2015-09-03 Richard Biener <rguenther@suse.de>

[official-gcc.git] / gcc / omp-low.c

/* Lowering pass for OMP directives.  Converts OMP directives into explicit
   calls to the runtime library (libgomp), data marshalling to implement data
   sharing and copying clauses, offloading to accelerators, and more.

   Contributed by Diego Novillo <dnovillo@redhat.com>

   Copyright (C) 2005-2015 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "cfghooks.h"
#include "tree.h"
#include "gimple.h"
#include "rtl.h"
#include "ssa.h"
#include "alias.h"
#include "fold-const.h"
#include "stor-layout.h"
#include "cfganal.h"
#include "internal-fn.h"
#include "gimple-fold.h"
#include "gimplify.h"
#include "gimple-iterator.h"
#include "gimplify-me.h"
#include "gimple-walk.h"
#include "tree-iterator.h"
#include "tree-inline.h"
#include "langhooks.h"
#include "diagnostic-core.h"
#include "cgraph.h"
#include "tree-cfg.h"
#include "tree-into-ssa.h"
#include "flags.h"
#include "insn-config.h"
#include "expmed.h"
#include "dojump.h"
#include "explow.h"
#include "calls.h"
#include "emit-rtl.h"
#include "varasm.h"
#include "stmt.h"
#include "expr.h"
#include "tree-dfa.h"
#include "tree-ssa.h"
#include "tree-pass.h"
#include "except.h"
#include "splay-tree.h"
#include "insn-codes.h"
#include "optabs.h"
#include "cfgloop.h"
#include "target.h"
#include "common/common-target.h"
#include "omp-low.h"
#include "gimple-low.h"
#include "tree-cfgcleanup.h"
#include "pretty-print.h"
#include "alloc-pool.h"
#include "symbol-summary.h"
#include "ipa-prop.h"
#include "tree-nested.h"
#include "tree-eh.h"
#include "cilk.h"
#include "context.h"
#include "lto-section-names.h"
#include "gomp-constants.h"


/* Lowering of OMP parallel and workshare constructs proceeds in two
   phases.  The first phase scans the function looking for OMP statements
   and then for variables that must be replaced to satisfy data sharing
   clauses.  The second phase expands code for the constructs, as well as
   re-gimplifying things when variables have been replaced with complex
   expressions.

   Final code generation is done by pass_expand_omp.  The flowgraph is
   scanned for regions which are then moved to a new
   function, to be invoked by the thread library, or offloaded.  */

/* OMP region information.  Every parallel and workshare
   directive is enclosed between two markers, the OMP_* directive
   and a corresponding OMP_RETURN statement.  */

struct omp_region
{
  /* The enclosing region.  */
  struct omp_region *outer;

  /* First child region.  */
  struct omp_region *inner;

  /* Next peer region.  */
  struct omp_region *next;

  /* Block containing the omp directive as its last stmt.  */
  basic_block entry;

  /* Block containing the OMP_RETURN as its last stmt.  */
  basic_block exit;

  /* Block containing the OMP_CONTINUE as its last stmt.  */
  basic_block cont;

  /* If this is a combined parallel+workshare region, this is a list
     of additional arguments needed by the combined parallel+workshare
     library call.  */
  vec<tree, va_gc> *ws_args;

  /* The code for the omp directive of this region.  */
  enum gimple_code type;

  /* Schedule kind, only used for OMP_FOR type regions.  */
  enum omp_clause_schedule_kind sched_kind;

  /* True if this is a combined parallel+workshare region.  */
  bool is_combined_parallel;
};

/* Levels of parallelism as defined by OpenACC.  Increasing numbers
   correspond to deeper loop nesting levels.  */
#define MASK_GANG 1
#define MASK_WORKER 2
#define MASK_VECTOR 4

/* Context structure.  Used to store information about each parallel
   directive in the code.  */

struct omp_context
{
  /* This field must be at the beginning, as we do "inheritance": Some
     callback functions for tree-inline.c (e.g., omp_copy_decl)
     receive a copy_body_data pointer that is up-casted to an
     omp_context pointer.  */
  copy_body_data cb;

  /* The tree of contexts corresponding to the encountered constructs.  */
  struct omp_context *outer;
  gimple stmt;

  /* Map variables to fields in a structure that allows communication
     between sending and receiving threads.  */
  splay_tree field_map;
  tree record_type;
  tree sender_decl;
  tree receiver_decl;

  /* These are used just by task contexts, if task firstprivate fn is
     needed.  srecord_type is used to communicate from the thread
     that encountered the task construct to task firstprivate fn,
     record_type is allocated by GOMP_task, initialized by task firstprivate
     fn and passed to the task body fn.  */
  splay_tree sfield_map;
  tree srecord_type;

  /* A chain of variables to add to the top-level block surrounding the
     construct.  In the case of a parallel, this is in the child function.  */
  tree block_vars;

  /* A map of reduction pointer variables.  For accelerators, each
     reduction variable is replaced with an array.  Each thread, in turn,
     is assigned to a slot on that array.  */
  splay_tree reduction_map;

  /* Label to which GOMP_cancel{,llation_point} and explicit and implicit
     barriers should jump to during omplower pass.  */
  tree cancel_label;

  /* What to do with variables with implicitly determined sharing
     attributes.  */
  enum omp_clause_default_kind default_kind;

  /* Nesting depth of this context.  Used to beautify error messages re
     invalid gotos.  The outermost ctx is depth 1, with depth 0 being
     reserved for the main body of the function.  */
  int depth;

  /* True if this parallel directive is nested within another.  */
  bool is_nested;

  /* True if this construct can be cancelled.  */
  bool cancellable;

  /* For OpenACC loops, a mask of gang, worker and vector used at
     levels below this one.  */
  int gwv_below;
  /* For OpenACC loops, a mask of gang, worker and vector used at
     this level and above.  For parallel and kernels clauses, a mask
     indicating which of num_gangs/num_workers/num_vectors was used.  */
  int gwv_this;
};

/* A structure holding the elements of:
   for (V = N1; V cond N2; V += STEP) [...] */

struct omp_for_data_loop
{
  tree v, n1, n2, step;
  enum tree_code cond_code;
};

/* A structure describing the main elements of a parallel loop.  */

struct omp_for_data
{
  struct omp_for_data_loop loop;
  tree chunk_size;
  gomp_for *for_stmt;
  tree pre, iter_type;
  int collapse;
  bool have_nowait, have_ordered;
  enum omp_clause_schedule_kind sched_kind;
  struct omp_for_data_loop *loops;
};


static splay_tree all_contexts;
static int taskreg_nesting_level;
static int target_nesting_level;
static struct omp_region *root_omp_region;
static bitmap task_shared_vars;
static vec<omp_context *> taskreg_contexts;

static void scan_omp (gimple_seq *, omp_context *);
static tree scan_omp_1_op (tree *, int *, void *);

#define WALK_SUBSTMTS  \
    case GIMPLE_BIND: \
    case GIMPLE_TRY: \
    case GIMPLE_CATCH: \
    case GIMPLE_EH_FILTER: \
    case GIMPLE_TRANSACTION: \
      /* The sub-statements for these should be walked.  */ \
      *handled_ops_p = false; \
      break;

/* Helper function to get the name of the array containing the partial
   reductions for OpenACC reductions.  */
static const char *
oacc_get_reduction_array_id (tree node)
{
  const char *id = IDENTIFIER_POINTER (DECL_NAME (node));
  int len = strlen ("OACC") + strlen (id);
  char *temp_name = XALLOCAVEC (char, len + 1);
  snprintf (temp_name, len + 1, "OACC%s", id);
  return IDENTIFIER_POINTER (get_identifier (temp_name));
}

/* Determine the number of threads OpenACC threads used to determine the
   size of the array of partial reductions.  Currently, this is num_gangs
   * vector_length.  This value may be different than GOACC_GET_NUM_THREADS,
   because it is independed of the device used.  */

static tree
oacc_max_threads (omp_context *ctx)
{
  tree nthreads, vector_length, gangs, clauses;

  gangs = fold_convert (sizetype, integer_one_node);
  vector_length = gangs;

  /* The reduction clause may be nested inside a loop directive.
     Scan for the innermost vector_length clause.  */
  for (omp_context *oc = ctx; oc; oc = oc->outer)
    {
      if (gimple_code (oc->stmt) != GIMPLE_OMP_TARGET
          || (gimple_omp_target_kind (oc->stmt)
              != GF_OMP_TARGET_KIND_OACC_PARALLEL))
        continue;

      clauses = gimple_omp_target_clauses (oc->stmt);

      vector_length = find_omp_clause (clauses, OMP_CLAUSE_VECTOR_LENGTH);
      if (vector_length)
        vector_length = fold_convert_loc (OMP_CLAUSE_LOCATION (vector_length),
                                          sizetype,
                                          OMP_CLAUSE_VECTOR_LENGTH_EXPR
                                          (vector_length));
      else
        vector_length = fold_convert (sizetype, integer_one_node);

      gangs = find_omp_clause (clauses, OMP_CLAUSE_NUM_GANGS);
      if (gangs)
        gangs = fold_convert_loc (OMP_CLAUSE_LOCATION (gangs), sizetype,
                                  OMP_CLAUSE_NUM_GANGS_EXPR (gangs));
      else
        gangs = fold_convert (sizetype, integer_one_node);

      break;
    }

  nthreads = fold_build2 (MULT_EXPR, sizetype, gangs, vector_length);

  return nthreads;
}

/* Holds offload tables with decls.  */
vec<tree, va_gc> *offload_funcs, *offload_vars;

/* Convenience function for calling scan_omp_1_op on tree operands.  */

static inline tree
scan_omp_op (tree *tp, omp_context *ctx)
{
  struct walk_stmt_info wi;

  memset (&wi, 0, sizeof (wi));
  wi.info = ctx;
  wi.want_locations = true;

  return walk_tree (tp, scan_omp_1_op, &wi, NULL);
}

static void lower_omp (gimple_seq *, omp_context *);
static tree lookup_decl_in_outer_ctx (tree, omp_context *);
static tree maybe_lookup_decl_in_outer_ctx (tree, omp_context *);

/* Find an OMP clause of type KIND within CLAUSES.  */

tree
find_omp_clause (tree clauses, enum omp_clause_code kind)
{
  for (; clauses ; clauses = OMP_CLAUSE_CHAIN (clauses))
    if (OMP_CLAUSE_CODE (clauses) == kind)
      return clauses;

  return NULL_TREE;
}

/* Return true if CTX is for an omp parallel.  */

static inline bool
is_parallel_ctx (omp_context *ctx)
{
  return gimple_code (ctx->stmt) == GIMPLE_OMP_PARALLEL;
}


/* Return true if CTX is for an omp task.  */

static inline bool
is_task_ctx (omp_context *ctx)
{
  return gimple_code (ctx->stmt) == GIMPLE_OMP_TASK;
}


/* Return true if CTX is for an omp parallel or omp task.  */

static inline bool
is_taskreg_ctx (omp_context *ctx)
{
  return gimple_code (ctx->stmt) == GIMPLE_OMP_PARALLEL
         || gimple_code (ctx->stmt) == GIMPLE_OMP_TASK;
}


/* Return true if REGION is a combined parallel+workshare region.  */

static inline bool
is_combined_parallel (struct omp_region *region)
{
  return region->is_combined_parallel;
}


/* Extract the header elements of parallel loop FOR_STMT and store
   them into *FD.  */

static void
extract_omp_for_data (gomp_for *for_stmt, struct omp_for_data *fd,
                      struct omp_for_data_loop *loops)
{
  tree t, var, *collapse_iter, *collapse_count;
  tree count = NULL_TREE, iter_type = long_integer_type_node;
  struct omp_for_data_loop *loop;
  int i;
  struct omp_for_data_loop dummy_loop;
  location_t loc = gimple_location (for_stmt);
  bool simd = gimple_omp_for_kind (for_stmt) & GF_OMP_FOR_SIMD;
  bool distribute = gimple_omp_for_kind (for_stmt)
                    == GF_OMP_FOR_KIND_DISTRIBUTE;

  fd->for_stmt = for_stmt;
  fd->pre = NULL;
  fd->collapse = gimple_omp_for_collapse (for_stmt);
  if (fd->collapse > 1)
    fd->loops = loops;
  else
    fd->loops = &fd->loop;

  fd->have_nowait = distribute || simd;
  fd->have_ordered = false;
  fd->sched_kind = OMP_CLAUSE_SCHEDULE_STATIC;
  fd->chunk_size = NULL_TREE;
  if (gimple_omp_for_kind (fd->for_stmt) == GF_OMP_FOR_KIND_CILKFOR)
    fd->sched_kind = OMP_CLAUSE_SCHEDULE_CILKFOR;
  collapse_iter = NULL;
  collapse_count = NULL;

  for (t = gimple_omp_for_clauses (for_stmt); t ; t = OMP_CLAUSE_CHAIN (t))
    switch (OMP_CLAUSE_CODE (t))
      {
      case OMP_CLAUSE_NOWAIT:
        fd->have_nowait = true;
        break;
      case OMP_CLAUSE_ORDERED:
        fd->have_ordered = true;
        break;
      case OMP_CLAUSE_SCHEDULE:
        gcc_assert (!distribute);
        fd->sched_kind = OMP_CLAUSE_SCHEDULE_KIND (t);
        fd->chunk_size = OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (t);
        break;
      case OMP_CLAUSE_DIST_SCHEDULE:
        gcc_assert (distribute);
        fd->chunk_size = OMP_CLAUSE_DIST_SCHEDULE_CHUNK_EXPR (t);
        break;
      case OMP_CLAUSE_COLLAPSE:
        if (fd->collapse > 1)
          {
            collapse_iter = &OMP_CLAUSE_COLLAPSE_ITERVAR (t);
            collapse_count = &OMP_CLAUSE_COLLAPSE_COUNT (t);
          }
        break;
      default:
        break;
      }

  /* FIXME: for now map schedule(auto) to schedule(static).
     There should be analysis to determine whether all iterations
     are approximately the same amount of work (then schedule(static)
     is best) or if it varies (then schedule(dynamic,N) is better).  */
  if (fd->sched_kind == OMP_CLAUSE_SCHEDULE_AUTO)
    {
      fd->sched_kind = OMP_CLAUSE_SCHEDULE_STATIC;
      gcc_assert (fd->chunk_size == NULL);
    }
  gcc_assert (fd->collapse == 1 || collapse_iter != NULL);
  if (fd->sched_kind == OMP_CLAUSE_SCHEDULE_RUNTIME)
    gcc_assert (fd->chunk_size == NULL);
  else if (fd->chunk_size == NULL)
    {
      /* We only need to compute a default chunk size for ordered
         static loops and dynamic loops.  */
      if (fd->sched_kind != OMP_CLAUSE_SCHEDULE_STATIC
          || fd->have_ordered)
        fd->chunk_size = (fd->sched_kind == OMP_CLAUSE_SCHEDULE_STATIC)
                         ? integer_zero_node : integer_one_node;
    }

  for (i = 0; i < fd->collapse; i++)
    {
      if (fd->collapse == 1)
        loop = &fd->loop;
      else if (loops != NULL)
        loop = loops + i;
      else
        loop = &dummy_loop;

      loop->v = gimple_omp_for_index (for_stmt, i);
      gcc_assert (SSA_VAR_P (loop->v));
      gcc_assert (TREE_CODE (TREE_TYPE (loop->v)) == INTEGER_TYPE
                  || TREE_CODE (TREE_TYPE (loop->v)) == POINTER_TYPE);
      var = TREE_CODE (loop->v) == SSA_NAME ? SSA_NAME_VAR (loop->v) : loop->v;
      loop->n1 = gimple_omp_for_initial (for_stmt, i);

      loop->cond_code = gimple_omp_for_cond (for_stmt, i);
      loop->n2 = gimple_omp_for_final (for_stmt, i);
      switch (loop->cond_code)
        {
        case LT_EXPR:
        case GT_EXPR:
          break;
        case NE_EXPR:
          gcc_assert (gimple_omp_for_kind (for_stmt)
                      == GF_OMP_FOR_KIND_CILKSIMD
                      || (gimple_omp_for_kind (for_stmt)
                          == GF_OMP_FOR_KIND_CILKFOR));
          break;
        case LE_EXPR:
          if (POINTER_TYPE_P (TREE_TYPE (loop->n2)))
            loop->n2 = fold_build_pointer_plus_hwi_loc (loc, loop->n2, 1);
          else
            loop->n2 = fold_build2_loc (loc,
                                    PLUS_EXPR, TREE_TYPE (loop->n2), loop->n2,
                                    build_int_cst (TREE_TYPE (loop->n2), 1));
          loop->cond_code = LT_EXPR;
          break;
        case GE_EXPR:
          if (POINTER_TYPE_P (TREE_TYPE (loop->n2)))
            loop->n2 = fold_build_pointer_plus_hwi_loc (loc, loop->n2, -1);
          else
            loop->n2 = fold_build2_loc (loc,
                                    MINUS_EXPR, TREE_TYPE (loop->n2), loop->n2,
                                    build_int_cst (TREE_TYPE (loop->n2), 1));
          loop->cond_code = GT_EXPR;
          break;
        default:
          gcc_unreachable ();
        }

      t = gimple_omp_for_incr (for_stmt, i);
      gcc_assert (TREE_OPERAND (t, 0) == var);
      switch (TREE_CODE (t))
        {
        case PLUS_EXPR:
          loop->step = TREE_OPERAND (t, 1);
          break;
        case POINTER_PLUS_EXPR:
          loop->step = fold_convert (ssizetype, TREE_OPERAND (t, 1));
          break;
        case MINUS_EXPR:
          loop->step = TREE_OPERAND (t, 1);
          loop->step = fold_build1_loc (loc,
                                    NEGATE_EXPR, TREE_TYPE (loop->step),
                                    loop->step);
          break;
        default:
          gcc_unreachable ();
        }

      if (simd
          || (fd->sched_kind == OMP_CLAUSE_SCHEDULE_STATIC
              && !fd->have_ordered))
        {
          if (fd->collapse == 1)
            iter_type = TREE_TYPE (loop->v);
          else if (i == 0
                   || TYPE_PRECISION (iter_type)
                      < TYPE_PRECISION (TREE_TYPE (loop->v)))
            iter_type
              = build_nonstandard_integer_type
                  (TYPE_PRECISION (TREE_TYPE (loop->v)), 1);
        }
      else if (iter_type != long_long_unsigned_type_node)
        {
          if (POINTER_TYPE_P (TREE_TYPE (loop->v)))
            iter_type = long_long_unsigned_type_node;
          else if (TYPE_UNSIGNED (TREE_TYPE (loop->v))
                   && TYPE_PRECISION (TREE_TYPE (loop->v))
                      >= TYPE_PRECISION (iter_type))
            {
              tree n;

              if (loop->cond_code == LT_EXPR)
                n = fold_build2_loc (loc,
                                 PLUS_EXPR, TREE_TYPE (loop->v),
                                 loop->n2, loop->step);
              else
                n = loop->n1;
              if (TREE_CODE (n) != INTEGER_CST
                  || tree_int_cst_lt (TYPE_MAX_VALUE (iter_type), n))
                iter_type = long_long_unsigned_type_node;
            }
          else if (TYPE_PRECISION (TREE_TYPE (loop->v))
                   > TYPE_PRECISION (iter_type))
            {
              tree n1, n2;

              if (loop->cond_code == LT_EXPR)
                {
                  n1 = loop->n1;
                  n2 = fold_build2_loc (loc,
                                    PLUS_EXPR, TREE_TYPE (loop->v),
                                    loop->n2, loop->step);
                }
              else
                {
                  n1 = fold_build2_loc (loc,
                                    MINUS_EXPR, TREE_TYPE (loop->v),
                                    loop->n2, loop->step);
                  n2 = loop->n1;
                }
              if (TREE_CODE (n1) != INTEGER_CST
                  || TREE_CODE (n2) != INTEGER_CST
                  || !tree_int_cst_lt (TYPE_MIN_VALUE (iter_type), n1)
                  || !tree_int_cst_lt (n2, TYPE_MAX_VALUE (iter_type)))
                iter_type = long_long_unsigned_type_node;
            }
        }

      if (collapse_count && *collapse_count == NULL)
        {
          t = fold_binary (loop->cond_code, boolean_type_node,
                           fold_convert (TREE_TYPE (loop->v), loop->n1),
                           fold_convert (TREE_TYPE (loop->v), loop->n2));
          if (t && integer_zerop (t))
            count = build_zero_cst (long_long_unsigned_type_node);
          else if ((i == 0 || count != NULL_TREE)
                   && TREE_CODE (TREE_TYPE (loop->v)) == INTEGER_TYPE
                   && TREE_CONSTANT (loop->n1)
                   && TREE_CONSTANT (loop->n2)
                   && TREE_CODE (loop->step) == INTEGER_CST)
            {
              tree itype = TREE_TYPE (loop->v);

              if (POINTER_TYPE_P (itype))
                itype = signed_type_for (itype);
              t = build_int_cst (itype, (loop->cond_code == LT_EXPR ? -1 : 1));
              t = fold_build2_loc (loc,
                               PLUS_EXPR, itype,
                               fold_convert_loc (loc, itype, loop->step), t);
              t = fold_build2_loc (loc, PLUS_EXPR, itype, t,
                               fold_convert_loc (loc, itype, loop->n2));
              t = fold_build2_loc (loc, MINUS_EXPR, itype, t,
                               fold_convert_loc (loc, itype, loop->n1));
              if (TYPE_UNSIGNED (itype) && loop->cond_code == GT_EXPR)
                t = fold_build2_loc (loc, TRUNC_DIV_EXPR, itype,
                                 fold_build1_loc (loc, NEGATE_EXPR, itype, t),
                                 fold_build1_loc (loc, NEGATE_EXPR, itype,
                                              fold_convert_loc (loc, itype,
                                                                loop->step)));
              else
                t = fold_build2_loc (loc, TRUNC_DIV_EXPR, itype, t,
                                 fold_convert_loc (loc, itype, loop->step));
              t = fold_convert_loc (loc, long_long_unsigned_type_node, t);
              if (count != NULL_TREE)
                count = fold_build2_loc (loc,
                                     MULT_EXPR, long_long_unsigned_type_node,
                                     count, t);
              else
                count = t;
              if (TREE_CODE (count) != INTEGER_CST)
                count = NULL_TREE;
            }
          else if (count && !integer_zerop (count))
            count = NULL_TREE;
        }
    }

  if (count
      && !simd
      && (fd->sched_kind != OMP_CLAUSE_SCHEDULE_STATIC
          || fd->have_ordered))
    {
      if (!tree_int_cst_lt (count, TYPE_MAX_VALUE (long_integer_type_node)))
        iter_type = long_long_unsigned_type_node;
      else
        iter_type = long_integer_type_node;
    }
  else if (collapse_iter && *collapse_iter != NULL)
    iter_type = TREE_TYPE (*collapse_iter);
  fd->iter_type = iter_type;
  if (collapse_iter && *collapse_iter == NULL)
    *collapse_iter = create_tmp_var (iter_type, ".iter");
  if (collapse_count && *collapse_count == NULL)
    {
      if (count)
        *collapse_count = fold_convert_loc (loc, iter_type, count);
      else
        *collapse_count = create_tmp_var (iter_type, ".count");
    }

  if (fd->collapse > 1)
    {
      fd->loop.v = *collapse_iter;
      fd->loop.n1 = build_int_cst (TREE_TYPE (fd->loop.v), 0);
      fd->loop.n2 = *collapse_count;
      fd->loop.step = build_int_cst (TREE_TYPE (fd->loop.v), 1);
      fd->loop.cond_code = LT_EXPR;
    }

  /* For OpenACC loops, force a chunk size of one, as this avoids the default
    scheduling where several subsequent iterations are being executed by the
    same thread.  */
  if (gimple_omp_for_kind (for_stmt) == GF_OMP_FOR_KIND_OACC_LOOP)
    {
      gcc_assert (fd->chunk_size == NULL_TREE);
      fd->chunk_size = build_int_cst (TREE_TYPE (fd->loop.v), 1);
    }
}


/* Given two blocks PAR_ENTRY_BB and WS_ENTRY_BB such that WS_ENTRY_BB
   is the immediate dominator of PAR_ENTRY_BB, return true if there
   are no data dependencies that would prevent expanding the parallel
   directive at PAR_ENTRY_BB as a combined parallel+workshare region.

   When expanding a combined parallel+workshare region, the call to
   the child function may need additional arguments in the case of
   GIMPLE_OMP_FOR regions.  In some cases, these arguments are
   computed out of variables passed in from the parent to the child
   via 'struct .omp_data_s'.  For instance:

        #pragma omp parallel for schedule (guided, i * 4)
        for (j ...)

   Is lowered into:

        # BLOCK 2 (PAR_ENTRY_BB)
        .omp_data_o.i = i;
        #pragma omp parallel [child fn: bar.omp_fn.0 ( ..., D.1598)

        # BLOCK 3 (WS_ENTRY_BB)
        .omp_data_i = &.omp_data_o;
        D.1667 = .omp_data_i->i;
        D.1598 = D.1667 * 4;
        #pragma omp for schedule (guided, D.1598)

   When we outline the parallel region, the call to the child function
   'bar.omp_fn.0' will need the value D.1598 in its argument list, but
   that value is computed *after* the call site.  So, in principle we
   cannot do the transformation.

   To see whether the code in WS_ENTRY_BB blocks the combined
   parallel+workshare call, we collect all the variables used in the
   GIMPLE_OMP_FOR header check whether they appear on the LHS of any
   statement in WS_ENTRY_BB.  If so, then we cannot emit the combined
   call.

   FIXME.  If we had the SSA form built at this point, we could merely
   hoist the code in block 3 into block 2 and be done with it.  But at
   this point we don't have dataflow information and though we could
   hack something up here, it is really not worth the aggravation.  */

static bool
workshare_safe_to_combine_p (basic_block ws_entry_bb)
{
  struct omp_for_data fd;
  gimple ws_stmt = last_stmt (ws_entry_bb);

  if (gimple_code (ws_stmt) == GIMPLE_OMP_SECTIONS)
    return true;

  gcc_assert (gimple_code (ws_stmt) == GIMPLE_OMP_FOR);

  extract_omp_for_data (as_a <gomp_for *> (ws_stmt), &fd, NULL);

  if (fd.collapse > 1 && TREE_CODE (fd.loop.n2) != INTEGER_CST)
    return false;
  if (fd.iter_type != long_integer_type_node)
    return false;

  /* FIXME.  We give up too easily here.  If any of these arguments
     are not constants, they will likely involve variables that have
     been mapped into fields of .omp_data_s for sharing with the child
     function.  With appropriate data flow, it would be possible to
     see through this.  */
  if (!is_gimple_min_invariant (fd.loop.n1)
      || !is_gimple_min_invariant (fd.loop.n2)
      || !is_gimple_min_invariant (fd.loop.step)
      || (fd.chunk_size && !is_gimple_min_invariant (fd.chunk_size)))
    return false;

  return true;
}


/* Collect additional arguments needed to emit a combined
   parallel+workshare call.  WS_STMT is the workshare directive being
   expanded.  */

static vec<tree, va_gc> *
get_ws_args_for (gimple par_stmt, gimple ws_stmt)
{
  tree t;
  location_t loc = gimple_location (ws_stmt);
  vec<tree, va_gc> *ws_args;

  if (gomp_for *for_stmt = dyn_cast <gomp_for *> (ws_stmt))
    {
      struct omp_for_data fd;
      tree n1, n2;

      extract_omp_for_data (for_stmt, &fd, NULL);
      n1 = fd.loop.n1;
      n2 = fd.loop.n2;

      if (gimple_omp_for_combined_into_p (for_stmt))
        {
          tree innerc
            = find_omp_clause (gimple_omp_parallel_clauses (par_stmt),
                               OMP_CLAUSE__LOOPTEMP_);
          gcc_assert (innerc);
          n1 = OMP_CLAUSE_DECL (innerc);
          innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                    OMP_CLAUSE__LOOPTEMP_);
          gcc_assert (innerc);
          n2 = OMP_CLAUSE_DECL (innerc);
        }

      vec_alloc (ws_args, 3 + (fd.chunk_size != 0));

      t = fold_convert_loc (loc, long_integer_type_node, n1);
      ws_args->quick_push (t);

      t = fold_convert_loc (loc, long_integer_type_node, n2);
      ws_args->quick_push (t);

      t = fold_convert_loc (loc, long_integer_type_node, fd.loop.step);
      ws_args->quick_push (t);

      if (fd.chunk_size)
        {
          t = fold_convert_loc (loc, long_integer_type_node, fd.chunk_size);
          ws_args->quick_push (t);
        }

      return ws_args;
    }
  else if (gimple_code (ws_stmt) == GIMPLE_OMP_SECTIONS)
    {
      /* Number of sections is equal to the number of edges from the
         GIMPLE_OMP_SECTIONS_SWITCH statement, except for the one to
         the exit of the sections region.  */
      basic_block bb = single_succ (gimple_bb (ws_stmt));
      t = build_int_cst (unsigned_type_node, EDGE_COUNT (bb->succs) - 1);
      vec_alloc (ws_args, 1);
      ws_args->quick_push (t);
      return ws_args;
    }

  gcc_unreachable ();
}


/* Discover whether REGION is a combined parallel+workshare region.  */

static void
determine_parallel_type (struct omp_region *region)
{
  basic_block par_entry_bb, par_exit_bb;
  basic_block ws_entry_bb, ws_exit_bb;

  if (region == NULL || region->inner == NULL
      || region->exit == NULL || region->inner->exit == NULL
      || region->inner->cont == NULL)
    return;

  /* We only support parallel+for and parallel+sections.  */
  if (region->type != GIMPLE_OMP_PARALLEL
      || (region->inner->type != GIMPLE_OMP_FOR
          && region->inner->type != GIMPLE_OMP_SECTIONS))
    return;

  /* Check for perfect nesting PAR_ENTRY_BB -> WS_ENTRY_BB and
     WS_EXIT_BB -> PAR_EXIT_BB.  */
  par_entry_bb = region->entry;
  par_exit_bb = region->exit;
  ws_entry_bb = region->inner->entry;
  ws_exit_bb = region->inner->exit;

  if (single_succ (par_entry_bb) == ws_entry_bb
      && single_succ (ws_exit_bb) == par_exit_bb
      && workshare_safe_to_combine_p (ws_entry_bb)
      && (gimple_omp_parallel_combined_p (last_stmt (par_entry_bb))
          || (last_and_only_stmt (ws_entry_bb)
              && last_and_only_stmt (par_exit_bb))))
    {
      gimple par_stmt = last_stmt (par_entry_bb);
      gimple ws_stmt = last_stmt (ws_entry_bb);

      if (region->inner->type == GIMPLE_OMP_FOR)
        {
          /* If this is a combined parallel loop, we need to determine
             whether or not to use the combined library calls.  There
             are two cases where we do not apply the transformation:
             static loops and any kind of ordered loop.  In the first
             case, we already open code the loop so there is no need
             to do anything else.  In the latter case, the combined
             parallel loop call would still need extra synchronization
             to implement ordered semantics, so there would not be any
             gain in using the combined call.  */
          tree clauses = gimple_omp_for_clauses (ws_stmt);
          tree c = find_omp_clause (clauses, OMP_CLAUSE_SCHEDULE);
          if (c == NULL
              || OMP_CLAUSE_SCHEDULE_KIND (c) == OMP_CLAUSE_SCHEDULE_STATIC
              || find_omp_clause (clauses, OMP_CLAUSE_ORDERED))
            {
              region->is_combined_parallel = false;
              region->inner->is_combined_parallel = false;
              return;
            }
        }

      region->is_combined_parallel = true;
      region->inner->is_combined_parallel = true;
      region->ws_args = get_ws_args_for (par_stmt, ws_stmt);
    }
}


/* Return true if EXPR is variable sized.  */

static inline bool
is_variable_sized (const_tree expr)
{
  return !TREE_CONSTANT (TYPE_SIZE_UNIT (TREE_TYPE (expr)));
}

/* Return true if DECL is a reference type.  */

static inline bool
is_reference (tree decl)
{
  return lang_hooks.decls.omp_privatize_by_reference (decl);
}

/* Return the type of a decl.  If the decl is reference type,
   return its base type.  */
static inline tree
get_base_type (tree decl)
{
  tree type = TREE_TYPE (decl);
  if (is_reference (decl))
    type = TREE_TYPE (type);
  return type;
}

/* Lookup variables.  The "maybe" form
   allows for the variable form to not have been entered, otherwise we
   assert that the variable must have been entered.  */

static inline tree
lookup_decl (tree var, omp_context *ctx)
{
  tree *n = ctx->cb.decl_map->get (var);
  return *n;
}

static inline tree
maybe_lookup_decl (const_tree var, omp_context *ctx)
{
  tree *n = ctx->cb.decl_map->get (const_cast<tree> (var));
  return n ? *n : NULL_TREE;
}

static inline tree
lookup_field (tree var, omp_context *ctx)
{
  splay_tree_node n;
  n = splay_tree_lookup (ctx->field_map, (splay_tree_key) var);
  return (tree) n->value;
}

static inline tree
lookup_sfield (tree var, omp_context *ctx)
{
  splay_tree_node n;
  n = splay_tree_lookup (ctx->sfield_map
                         ? ctx->sfield_map : ctx->field_map,
                         (splay_tree_key) var);
  return (tree) n->value;
}

static inline tree
maybe_lookup_field (tree var, omp_context *ctx)
{
  splay_tree_node n;
  n = splay_tree_lookup (ctx->field_map, (splay_tree_key) var);
  return n ? (tree) n->value : NULL_TREE;
}

static inline tree
lookup_oacc_reduction (const char *id, omp_context *ctx)
{
  splay_tree_node n;
  n = splay_tree_lookup (ctx->reduction_map, (splay_tree_key) id);
  return (tree) n->value;
}

static inline tree
maybe_lookup_oacc_reduction (tree var, omp_context *ctx)
{
  splay_tree_node n = NULL;
  if (ctx->reduction_map)
    n = splay_tree_lookup (ctx->reduction_map, (splay_tree_key) var);
  return n ? (tree) n->value : NULL_TREE;
}

/* Return true if DECL should be copied by pointer.  SHARED_CTX is
   the parallel context if DECL is to be shared.  */

static bool
use_pointer_for_field (tree decl, omp_context *shared_ctx)
{
  if (AGGREGATE_TYPE_P (TREE_TYPE (decl)))
    return true;

  /* We can only use copy-in/copy-out semantics for shared variables
     when we know the value is not accessible from an outer scope.  */
  if (shared_ctx)
    {
      gcc_assert (!is_gimple_omp_oacc (shared_ctx->stmt));

      /* ??? Trivially accessible from anywhere.  But why would we even
         be passing an address in this case?  Should we simply assert
         this to be false, or should we have a cleanup pass that removes
         these from the list of mappings?  */
      if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
        return true;

      /* For variables with DECL_HAS_VALUE_EXPR_P set, we cannot tell
         without analyzing the expression whether or not its location
         is accessible to anyone else.  In the case of nested parallel
         regions it certainly may be.  */
      if (TREE_CODE (decl) != RESULT_DECL && DECL_HAS_VALUE_EXPR_P (decl))
        return true;

      /* Do not use copy-in/copy-out for variables that have their
         address taken.  */
      if (TREE_ADDRESSABLE (decl))
        return true;

      /* lower_send_shared_vars only uses copy-in, but not copy-out
         for these.  */
      if (TREE_READONLY (decl)
          || ((TREE_CODE (decl) == RESULT_DECL
               || TREE_CODE (decl) == PARM_DECL)
              && DECL_BY_REFERENCE (decl)))
        return false;

      /* Disallow copy-in/out in nested parallel if
         decl is shared in outer parallel, otherwise
         each thread could store the shared variable
         in its own copy-in location, making the
         variable no longer really shared.  */
      if (shared_ctx->is_nested)
        {
          omp_context *up;

          for (up = shared_ctx->outer; up; up = up->outer)
            if (is_taskreg_ctx (up) && maybe_lookup_decl (decl, up))
              break;

          if (up)
            {
              tree c;

              for (c = gimple_omp_taskreg_clauses (up->stmt);
                   c; c = OMP_CLAUSE_CHAIN (c))
                if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_SHARED
                    && OMP_CLAUSE_DECL (c) == decl)
                  break;

              if (c)
                goto maybe_mark_addressable_and_ret;
            }
        }

      /* For tasks avoid using copy-in/out.  As tasks can be
         deferred or executed in different thread, when GOMP_task
         returns, the task hasn't necessarily terminated.  */
      if (is_task_ctx (shared_ctx))
        {
          tree outer;
        maybe_mark_addressable_and_ret:
          outer = maybe_lookup_decl_in_outer_ctx (decl, shared_ctx);
          if (is_gimple_reg (outer))
            {
              /* Taking address of OUTER in lower_send_shared_vars
                 might need regimplification of everything that uses the
                 variable.  */
              if (!task_shared_vars)
                task_shared_vars = BITMAP_ALLOC (NULL);
              bitmap_set_bit (task_shared_vars, DECL_UID (outer));
              TREE_ADDRESSABLE (outer) = 1;
            }
          return true;
        }
    }

  return false;
}

/* Construct a new automatic decl similar to VAR.  */

static tree
omp_copy_decl_2 (tree var, tree name, tree type, omp_context *ctx)
{
  tree copy = copy_var_decl (var, name, type);

  DECL_CONTEXT (copy) = current_function_decl;
  DECL_CHAIN (copy) = ctx->block_vars;
  ctx->block_vars = copy;

  return copy;
}

static tree
omp_copy_decl_1 (tree var, omp_context *ctx)
{
  return omp_copy_decl_2 (var, DECL_NAME (var), TREE_TYPE (var), ctx);
}

/* Build COMPONENT_REF and set TREE_THIS_VOLATILE and TREE_READONLY on it
   as appropriate.  */
static tree
omp_build_component_ref (tree obj, tree field)
{
  tree ret = build3 (COMPONENT_REF, TREE_TYPE (field), obj, field, NULL);
  if (TREE_THIS_VOLATILE (field))
    TREE_THIS_VOLATILE (ret) |= 1;
  if (TREE_READONLY (field))
    TREE_READONLY (ret) |= 1;
  return ret;
}

/* Build tree nodes to access the field for VAR on the receiver side.  */

static tree
build_receiver_ref (tree var, bool by_ref, omp_context *ctx)
{
  tree x, field = lookup_field (var, ctx);

  /* If the receiver record type was remapped in the child function,
     remap the field into the new record type.  */
  x = maybe_lookup_field (field, ctx);
  if (x != NULL)
    field = x;

  x = build_simple_mem_ref (ctx->receiver_decl);
  TREE_THIS_NOTRAP (x) = 1;
  x = omp_build_component_ref (x, field);
  if (by_ref)
    x = build_simple_mem_ref (x);

  return x;
}

/* Build tree nodes to access VAR in the scope outer to CTX.  In the case
   of a parallel, this is a component reference; for workshare constructs
   this is some variable.  */

static tree
build_outer_var_ref (tree var, omp_context *ctx)
{
  tree x;

  if (is_global_var (maybe_lookup_decl_in_outer_ctx (var, ctx)))
    x = var;
  else if (is_variable_sized (var))
    {
      x = TREE_OPERAND (DECL_VALUE_EXPR (var), 0);
      x = build_outer_var_ref (x, ctx);
      x = build_simple_mem_ref (x);
    }
  else if (is_taskreg_ctx (ctx))
    {
      bool by_ref = use_pointer_for_field (var, NULL);
      x = build_receiver_ref (var, by_ref, ctx);
    }
  else if (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR
           && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD)
    {
      /* #pragma omp simd isn't a worksharing construct, and can reference even
         private vars in its linear etc. clauses.  */
      x = NULL_TREE;
      if (ctx->outer && is_taskreg_ctx (ctx))
        x = lookup_decl (var, ctx->outer);
      else if (ctx->outer)
        x = maybe_lookup_decl_in_outer_ctx (var, ctx);
      if (x == NULL_TREE)
        x = var;
    }
  else if (ctx->outer)
    x = lookup_decl (var, ctx->outer);
  else if (is_reference (var))
    /* This can happen with orphaned constructs.  If var is reference, it is
       possible it is shared and as such valid.  */
    x = var;
  else
    gcc_unreachable ();

  if (is_reference (var))
    x = build_simple_mem_ref (x);

  return x;
}

/* Build tree nodes to access the field for VAR on the sender side.  */

static tree
build_sender_ref (tree var, omp_context *ctx)
{
  tree field = lookup_sfield (var, ctx);
  return omp_build_component_ref (ctx->sender_decl, field);
}

/* Add a new field for VAR inside the structure CTX->SENDER_DECL.  */

static void
install_var_field (tree var, bool by_ref, int mask, omp_context *ctx)
{
  tree field, type, sfield = NULL_TREE;

  gcc_assert ((mask & 1) == 0
              || !splay_tree_lookup (ctx->field_map, (splay_tree_key) var));
  gcc_assert ((mask & 2) == 0 || !ctx->sfield_map
              || !splay_tree_lookup (ctx->sfield_map, (splay_tree_key) var));
  gcc_assert ((mask & 3) == 3
              || !is_gimple_omp_oacc (ctx->stmt));

  type = TREE_TYPE (var);
  if (mask & 4)
    {
      gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
      type = build_pointer_type (build_pointer_type (type));
    }
  else if (by_ref)
    type = build_pointer_type (type);
  else if ((mask & 3) == 1 && is_reference (var))
    type = TREE_TYPE (type);

  field = build_decl (DECL_SOURCE_LOCATION (var),
                      FIELD_DECL, DECL_NAME (var), type);

  /* Remember what variable this field was created for.  This does have a
     side effect of making dwarf2out ignore this member, so for helpful
     debugging we clear it later in delete_omp_context.  */
  DECL_ABSTRACT_ORIGIN (field) = var;
  if (type == TREE_TYPE (var))
    {
      DECL_ALIGN (field) = DECL_ALIGN (var);
      DECL_USER_ALIGN (field) = DECL_USER_ALIGN (var);
      TREE_THIS_VOLATILE (field) = TREE_THIS_VOLATILE (var);
    }
  else
    DECL_ALIGN (field) = TYPE_ALIGN (type);

  if ((mask & 3) == 3)
    {
      insert_field_into_struct (ctx->record_type, field);
      if (ctx->srecord_type)
        {
          sfield = build_decl (DECL_SOURCE_LOCATION (var),
                               FIELD_DECL, DECL_NAME (var), type);
          DECL_ABSTRACT_ORIGIN (sfield) = var;
          DECL_ALIGN (sfield) = DECL_ALIGN (field);
          DECL_USER_ALIGN (sfield) = DECL_USER_ALIGN (field);
          TREE_THIS_VOLATILE (sfield) = TREE_THIS_VOLATILE (field);
          insert_field_into_struct (ctx->srecord_type, sfield);
        }
    }
  else
    {
      if (ctx->srecord_type == NULL_TREE)
        {
          tree t;

          ctx->srecord_type = lang_hooks.types.make_type (RECORD_TYPE);
          ctx->sfield_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
          for (t = TYPE_FIELDS (ctx->record_type); t ; t = TREE_CHAIN (t))
            {
              sfield = build_decl (DECL_SOURCE_LOCATION (var),
                                   FIELD_DECL, DECL_NAME (t), TREE_TYPE (t));
              DECL_ABSTRACT_ORIGIN (sfield) = DECL_ABSTRACT_ORIGIN (t);
              insert_field_into_struct (ctx->srecord_type, sfield);
              splay_tree_insert (ctx->sfield_map,
                                 (splay_tree_key) DECL_ABSTRACT_ORIGIN (t),
                                 (splay_tree_value) sfield);
            }
        }
      sfield = field;
      insert_field_into_struct ((mask & 1) ? ctx->record_type
                                : ctx->srecord_type, field);
    }

  if (mask & 1)
    splay_tree_insert (ctx->field_map, (splay_tree_key) var,
                       (splay_tree_value) field);
  if ((mask & 2) && ctx->sfield_map)
    splay_tree_insert (ctx->sfield_map, (splay_tree_key) var,
                       (splay_tree_value) sfield);
}

static tree
install_var_local (tree var, omp_context *ctx)
{
  tree new_var = omp_copy_decl_1 (var, ctx);
  insert_decl_map (&ctx->cb, var, new_var);
  return new_var;
}

/* Adjust the replacement for DECL in CTX for the new context.  This means
   copying the DECL_VALUE_EXPR, and fixing up the type.  */

static void
fixup_remapped_decl (tree decl, omp_context *ctx, bool private_debug)
{
  tree new_decl, size;

  new_decl = lookup_decl (decl, ctx);

  TREE_TYPE (new_decl) = remap_type (TREE_TYPE (decl), &ctx->cb);

  if ((!TREE_CONSTANT (DECL_SIZE (new_decl)) || private_debug)
      && DECL_HAS_VALUE_EXPR_P (decl))
    {
      tree ve = DECL_VALUE_EXPR (decl);
      walk_tree (&ve, copy_tree_body_r, &ctx->cb, NULL);
      SET_DECL_VALUE_EXPR (new_decl, ve);
      DECL_HAS_VALUE_EXPR_P (new_decl) = 1;
    }

  if (!TREE_CONSTANT (DECL_SIZE (new_decl)))
    {
      size = remap_decl (DECL_SIZE (decl), &ctx->cb);
      if (size == error_mark_node)
        size = TYPE_SIZE (TREE_TYPE (new_decl));
      DECL_SIZE (new_decl) = size;

      size = remap_decl (DECL_SIZE_UNIT (decl), &ctx->cb);
      if (size == error_mark_node)
        size = TYPE_SIZE_UNIT (TREE_TYPE (new_decl));
      DECL_SIZE_UNIT (new_decl) = size;
    }
}

/* The callback for remap_decl.  Search all containing contexts for a
   mapping of the variable; this avoids having to duplicate the splay
   tree ahead of time.  We know a mapping doesn't already exist in the
   given context.  Create new mappings to implement default semantics.  */

static tree
omp_copy_decl (tree var, copy_body_data *cb)
{
  omp_context *ctx = (omp_context *) cb;
  tree new_var;

  if (TREE_CODE (var) == LABEL_DECL)
    {
      new_var = create_artificial_label (DECL_SOURCE_LOCATION (var));
      DECL_CONTEXT (new_var) = current_function_decl;
      insert_decl_map (&ctx->cb, var, new_var);
      return new_var;
    }

  while (!is_taskreg_ctx (ctx))
    {
      ctx = ctx->outer;
      if (ctx == NULL)
        return var;
      new_var = maybe_lookup_decl (var, ctx);
      if (new_var)
        return new_var;
    }

  if (is_global_var (var) || decl_function_context (var) != ctx->cb.src_fn)
    return var;

  return error_mark_node;
}


/* Debugging dumps for parallel regions.  */
void dump_omp_region (FILE *, struct omp_region *, int);
void debug_omp_region (struct omp_region *);
void debug_all_omp_regions (void);

/* Dump the parallel region tree rooted at REGION.  */

void
dump_omp_region (FILE *file, struct omp_region *region, int indent)
{
  fprintf (file, "%*sbb %d: %s\n", indent, "", region->entry->index,
           gimple_code_name[region->type]);

  if (region->inner)
    dump_omp_region (file, region->inner, indent + 4);

  if (region->cont)
    {
      fprintf (file, "%*sbb %d: GIMPLE_OMP_CONTINUE\n", indent, "",
               region->cont->index);
    }

  if (region->exit)
    fprintf (file, "%*sbb %d: GIMPLE_OMP_RETURN\n", indent, "",
             region->exit->index);
  else
    fprintf (file, "%*s[no exit marker]\n", indent, "");

  if (region->next)
    dump_omp_region (file, region->next, indent);
}

DEBUG_FUNCTION void
debug_omp_region (struct omp_region *region)
{
  dump_omp_region (stderr, region, 0);
}

DEBUG_FUNCTION void
debug_all_omp_regions (void)
{
  dump_omp_region (stderr, root_omp_region, 0);
}


/* Create a new parallel region starting at STMT inside region PARENT.  */

static struct omp_region *
new_omp_region (basic_block bb, enum gimple_code type,
                struct omp_region *parent)
{
  struct omp_region *region = XCNEW (struct omp_region);

  region->outer = parent;
  region->entry = bb;
  region->type = type;

  if (parent)
    {
      /* This is a nested region.  Add it to the list of inner
         regions in PARENT.  */
      region->next = parent->inner;
      parent->inner = region;
    }
  else
    {
      /* This is a toplevel region.  Add it to the list of toplevel
         regions in ROOT_OMP_REGION.  */
      region->next = root_omp_region;
      root_omp_region = region;
    }

  return region;
}

/* Release the memory associated with the region tree rooted at REGION.  */

static void
free_omp_region_1 (struct omp_region *region)
{
  struct omp_region *i, *n;

  for (i = region->inner; i ; i = n)
    {
      n = i->next;
      free_omp_region_1 (i);
    }

  free (region);
}

/* Release the memory for the entire omp region tree.  */

void
free_omp_regions (void)
{
  struct omp_region *r, *n;
  for (r = root_omp_region; r ; r = n)
    {
      n = r->next;
      free_omp_region_1 (r);
    }
  root_omp_region = NULL;
}


/* Create a new context, with OUTER_CTX being the surrounding context.  */

static omp_context *
new_omp_context (gimple stmt, omp_context *outer_ctx)
{
  omp_context *ctx = XCNEW (omp_context);

  splay_tree_insert (all_contexts, (splay_tree_key) stmt,
                     (splay_tree_value) ctx);
  ctx->stmt = stmt;

  if (outer_ctx)
    {
      ctx->outer = outer_ctx;
      ctx->cb = outer_ctx->cb;
      ctx->cb.block = NULL;
      ctx->depth = outer_ctx->depth + 1;
      ctx->reduction_map = outer_ctx->reduction_map;
    }
  else
    {
      ctx->cb.src_fn = current_function_decl;
      ctx->cb.dst_fn = current_function_decl;
      ctx->cb.src_node = cgraph_node::get (current_function_decl);
      gcc_checking_assert (ctx->cb.src_node);
      ctx->cb.dst_node = ctx->cb.src_node;
      ctx->cb.src_cfun = cfun;
      ctx->cb.copy_decl = omp_copy_decl;
      ctx->cb.eh_lp_nr = 0;
      ctx->cb.transform_call_graph_edges = CB_CGE_MOVE;
      ctx->depth = 1;
    }

  ctx->cb.decl_map = new hash_map<tree, tree>;

  return ctx;
}

static gimple_seq maybe_catch_exception (gimple_seq);

/* Finalize task copyfn.  */

static void
finalize_task_copyfn (gomp_task *task_stmt)
{
  struct function *child_cfun;
  tree child_fn;
  gimple_seq seq = NULL, new_seq;
  gbind *bind;

  child_fn = gimple_omp_task_copy_fn (task_stmt);
  if (child_fn == NULL_TREE)
    return;

  child_cfun = DECL_STRUCT_FUNCTION (child_fn);
  DECL_STRUCT_FUNCTION (child_fn)->curr_properties = cfun->curr_properties;

  push_cfun (child_cfun);
  bind = gimplify_body (child_fn, false);
  gimple_seq_add_stmt (&seq, bind);
  new_seq = maybe_catch_exception (seq);
  if (new_seq != seq)
    {
      bind = gimple_build_bind (NULL, new_seq, NULL);
      seq = NULL;
      gimple_seq_add_stmt (&seq, bind);
    }
  gimple_set_body (child_fn, seq);
  pop_cfun ();

  /* Inform the callgraph about the new function.  */
  cgraph_node *node = cgraph_node::get_create (child_fn);
  node->parallelized_function = 1;
  cgraph_node::add_new_function (child_fn, false);
}

/* Destroy a omp_context data structures.  Called through the splay tree
   value delete callback.  */

static void
delete_omp_context (splay_tree_value value)
{
  omp_context *ctx = (omp_context *) value;

  delete ctx->cb.decl_map;

  if (ctx->field_map)
    splay_tree_delete (ctx->field_map);
  if (ctx->sfield_map)
    splay_tree_delete (ctx->sfield_map);
  /* Reduction map is copied to nested contexts, so only delete it in the
     owner.  */
  if (ctx->reduction_map
      && gimple_code (ctx->stmt) == GIMPLE_OMP_TARGET
      && is_gimple_omp_offloaded (ctx->stmt)
      && is_gimple_omp_oacc (ctx->stmt))
    splay_tree_delete (ctx->reduction_map);

  /* We hijacked DECL_ABSTRACT_ORIGIN earlier.  We need to clear it before
     it produces corrupt debug information.  */
  if (ctx->record_type)
    {
      tree t;
      for (t = TYPE_FIELDS (ctx->record_type); t ; t = DECL_CHAIN (t))
        DECL_ABSTRACT_ORIGIN (t) = NULL;
    }
  if (ctx->srecord_type)
    {
      tree t;
      for (t = TYPE_FIELDS (ctx->srecord_type); t ; t = DECL_CHAIN (t))
        DECL_ABSTRACT_ORIGIN (t) = NULL;
    }

  if (is_task_ctx (ctx))
    finalize_task_copyfn (as_a <gomp_task *> (ctx->stmt));

  XDELETE (ctx);
}

/* Fix up RECEIVER_DECL with a type that has been remapped to the child
   context.  */

static void
fixup_child_record_type (omp_context *ctx)
{
  tree f, type = ctx->record_type;

  /* ??? It isn't sufficient to just call remap_type here, because
     variably_modified_type_p doesn't work the way we expect for
     record types.  Testing each field for whether it needs remapping
     and creating a new record by hand works, however.  */
  for (f = TYPE_FIELDS (type); f ; f = DECL_CHAIN (f))
    if (variably_modified_type_p (TREE_TYPE (f), ctx->cb.src_fn))
      break;
  if (f)
    {
      tree name, new_fields = NULL;

      type = lang_hooks.types.make_type (RECORD_TYPE);
      name = DECL_NAME (TYPE_NAME (ctx->record_type));
      name = build_decl (DECL_SOURCE_LOCATION (ctx->receiver_decl),
                         TYPE_DECL, name, type);
      TYPE_NAME (type) = name;

      for (f = TYPE_FIELDS (ctx->record_type); f ; f = DECL_CHAIN (f))
        {
          tree new_f = copy_node (f);
          DECL_CONTEXT (new_f) = type;
          TREE_TYPE (new_f) = remap_type (TREE_TYPE (f), &ctx->cb);
          DECL_CHAIN (new_f) = new_fields;
          walk_tree (&DECL_SIZE (new_f), copy_tree_body_r, &ctx->cb, NULL);
          walk_tree (&DECL_SIZE_UNIT (new_f), copy_tree_body_r,
                     &ctx->cb, NULL);
          walk_tree (&DECL_FIELD_OFFSET (new_f), copy_tree_body_r,
                     &ctx->cb, NULL);
          new_fields = new_f;

          /* Arrange to be able to look up the receiver field
             given the sender field.  */
          splay_tree_insert (ctx->field_map, (splay_tree_key) f,
                             (splay_tree_value) new_f);
        }
      TYPE_FIELDS (type) = nreverse (new_fields);
      layout_type (type);
    }

  TREE_TYPE (ctx->receiver_decl)
    = build_qualified_type (build_reference_type (type), TYPE_QUAL_RESTRICT);
}

/* Instantiate decls as necessary in CTX to satisfy the data sharing
   specified by CLAUSES.  */

static void
scan_sharing_clauses (tree clauses, omp_context *ctx)
{
  tree c, decl;
  bool scan_array_reductions = false;

  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
    {
      bool by_ref;

      switch (OMP_CLAUSE_CODE (c))
        {
        case OMP_CLAUSE_PRIVATE:
          decl = OMP_CLAUSE_DECL (c);
          if (OMP_CLAUSE_PRIVATE_OUTER_REF (c))
            goto do_private;
          else if (!is_variable_sized (decl))
            install_var_local (decl, ctx);
          break;

        case OMP_CLAUSE_SHARED:
          decl = OMP_CLAUSE_DECL (c);
          /* Ignore shared directives in teams construct.  */
          if (gimple_code (ctx->stmt) == GIMPLE_OMP_TEAMS)
            {
              /* Global variables don't need to be copied,
                 the receiver side will use them directly.  */
              tree odecl = maybe_lookup_decl_in_outer_ctx (decl, ctx);
              if (is_global_var (odecl))
                break;
              insert_decl_map (&ctx->cb, decl, odecl);
              break;
            }
          gcc_assert (is_taskreg_ctx (ctx));
          gcc_assert (!COMPLETE_TYPE_P (TREE_TYPE (decl))
                      || !is_variable_sized (decl));
          /* Global variables don't need to be copied,
             the receiver side will use them directly.  */
          if (is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx)))
            break;
          by_ref = use_pointer_for_field (decl, ctx);
          if (! TREE_READONLY (decl)
              || TREE_ADDRESSABLE (decl)
              || by_ref
              || is_reference (decl))
            {
              install_var_field (decl, by_ref, 3, ctx);
              install_var_local (decl, ctx);
              break;
            }
          /* We don't need to copy const scalar vars back.  */
          OMP_CLAUSE_SET_CODE (c, OMP_CLAUSE_FIRSTPRIVATE);
          goto do_private;

        case OMP_CLAUSE_LASTPRIVATE:
          /* Let the corresponding firstprivate clause create
             the variable.  */
          if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
            break;
          /* FALLTHRU */

        case OMP_CLAUSE_FIRSTPRIVATE:
          if (is_gimple_omp_oacc (ctx->stmt))
            {
              sorry ("clause not supported yet");
              break;
            }
          /* FALLTHRU */
        case OMP_CLAUSE_REDUCTION:
        case OMP_CLAUSE_LINEAR:
          decl = OMP_CLAUSE_DECL (c);
        do_private:
          if (is_variable_sized (decl))
            {
              if (is_task_ctx (ctx))
                install_var_field (decl, false, 1, ctx);
              break;
            }
          else if (is_taskreg_ctx (ctx))
            {
              bool global
                = is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx));
              by_ref = use_pointer_for_field (decl, NULL);

              if (is_task_ctx (ctx)
                  && (global || by_ref || is_reference (decl)))
                {
                  install_var_field (decl, false, 1, ctx);
                  if (!global)
                    install_var_field (decl, by_ref, 2, ctx);
                }
              else if (!global)
                install_var_field (decl, by_ref, 3, ctx);
            }
          install_var_local (decl, ctx);
          if (is_gimple_omp_oacc (ctx->stmt)
              && OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION)
            {
              /* Create a decl for the reduction array.  */
              tree var = OMP_CLAUSE_DECL (c);
              tree type = get_base_type (var);
              tree ptype = build_pointer_type (type);
              tree array = create_tmp_var (ptype,
                                           oacc_get_reduction_array_id (var));
              omp_context *c = (ctx->field_map ? ctx : ctx->outer);
              install_var_field (array, true, 3, c);
              install_var_local (array, c);

              /* Insert it into the current context.  */
              splay_tree_insert (ctx->reduction_map, (splay_tree_key)
                                 oacc_get_reduction_array_id (var),
                                 (splay_tree_value) array);
              splay_tree_insert (ctx->reduction_map,
                                 (splay_tree_key) array,
                                 (splay_tree_value) array);
            }
          break;

        case OMP_CLAUSE__LOOPTEMP_:
          gcc_assert (is_parallel_ctx (ctx));
          decl = OMP_CLAUSE_DECL (c);
          install_var_field (decl, false, 3, ctx);
          install_var_local (decl, ctx);
          break;

        case OMP_CLAUSE_COPYPRIVATE:
        case OMP_CLAUSE_COPYIN:
          decl = OMP_CLAUSE_DECL (c);
          by_ref = use_pointer_for_field (decl, NULL);
          install_var_field (decl, by_ref, 3, ctx);
          break;

        case OMP_CLAUSE_DEFAULT:
          ctx->default_kind = OMP_CLAUSE_DEFAULT_KIND (c);
          break;

        case OMP_CLAUSE_FINAL:
        case OMP_CLAUSE_IF:
        case OMP_CLAUSE_NUM_THREADS:
        case OMP_CLAUSE_NUM_TEAMS:
        case OMP_CLAUSE_THREAD_LIMIT:
        case OMP_CLAUSE_DEVICE:
        case OMP_CLAUSE_SCHEDULE:
        case OMP_CLAUSE_DIST_SCHEDULE:
        case OMP_CLAUSE_DEPEND:
        case OMP_CLAUSE__CILK_FOR_COUNT_:
        case OMP_CLAUSE_NUM_GANGS:
        case OMP_CLAUSE_NUM_WORKERS:
        case OMP_CLAUSE_VECTOR_LENGTH:
          if (ctx->outer)
            scan_omp_op (&OMP_CLAUSE_OPERAND (c, 0), ctx->outer);
          break;

        case OMP_CLAUSE_TO:
        case OMP_CLAUSE_FROM:
        case OMP_CLAUSE_MAP:
          if (ctx->outer)
            scan_omp_op (&OMP_CLAUSE_SIZE (c), ctx->outer);
          decl = OMP_CLAUSE_DECL (c);
          /* Global variables with "omp declare target" attribute
             don't need to be copied, the receiver side will use them
             directly.  */
          if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
              && DECL_P (decl)
              && is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx))
              && varpool_node::get_create (decl)->offloadable)
            break;
          if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
              && OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER)
            {
              /* Ignore GOMP_MAP_POINTER kind for arrays in regions that are
                 not offloaded; there is nothing to map for those.  */
              if (!is_gimple_omp_offloaded (ctx->stmt)
                  && !POINTER_TYPE_P (TREE_TYPE (decl))
                  && !OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c))
                break;
            }
          if (DECL_P (decl))
            {
              if (DECL_SIZE (decl)
                  && TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
                {
                  tree decl2 = DECL_VALUE_EXPR (decl);
                  gcc_assert (TREE_CODE (decl2) == INDIRECT_REF);
                  decl2 = TREE_OPERAND (decl2, 0);
                  gcc_assert (DECL_P (decl2));
                  install_var_field (decl2, true, 3, ctx);
                  install_var_local (decl2, ctx);
                  install_var_local (decl, ctx);
                }
              else
                {
                  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
                      && OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
                      && !OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c)
                      && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
                    install_var_field (decl, true, 7, ctx);
                  else
                    install_var_field (decl, true, 3, ctx);
                  if (is_gimple_omp_offloaded (ctx->stmt))
                    install_var_local (decl, ctx);
                }
            }
          else
            {
              tree base = get_base_address (decl);
              tree nc = OMP_CLAUSE_CHAIN (c);
              if (DECL_P (base)
                  && nc != NULL_TREE
                  && OMP_CLAUSE_CODE (nc) == OMP_CLAUSE_MAP
                  && OMP_CLAUSE_DECL (nc) == base
                  && OMP_CLAUSE_MAP_KIND (nc) == GOMP_MAP_POINTER
                  && integer_zerop (OMP_CLAUSE_SIZE (nc)))
                {
                  OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c) = 1;
                  OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (nc) = 1;
                }
              else
                {
                  if (ctx->outer)
                    {
                      scan_omp_op (&OMP_CLAUSE_DECL (c), ctx->outer);
                      decl = OMP_CLAUSE_DECL (c);
                    }
                  gcc_assert (!splay_tree_lookup (ctx->field_map,
                                                  (splay_tree_key) decl));
                  tree field
                    = build_decl (OMP_CLAUSE_LOCATION (c),
                                  FIELD_DECL, NULL_TREE, ptr_type_node);
                  DECL_ALIGN (field) = TYPE_ALIGN (ptr_type_node);
                  insert_field_into_struct (ctx->record_type, field);
                  splay_tree_insert (ctx->field_map, (splay_tree_key) decl,
                                     (splay_tree_value) field);
                }
            }
          break;

        case OMP_CLAUSE_NOWAIT:
        case OMP_CLAUSE_ORDERED:
        case OMP_CLAUSE_COLLAPSE:
        case OMP_CLAUSE_UNTIED:
        case OMP_CLAUSE_MERGEABLE:
        case OMP_CLAUSE_PROC_BIND:
        case OMP_CLAUSE_SAFELEN:
        case OMP_CLAUSE_ASYNC:
        case OMP_CLAUSE_WAIT:
        case OMP_CLAUSE_GANG:
        case OMP_CLAUSE_WORKER:
        case OMP_CLAUSE_VECTOR:
          break;

        case OMP_CLAUSE_ALIGNED:
          decl = OMP_CLAUSE_DECL (c);
          if (is_global_var (decl)
              && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
            install_var_local (decl, ctx);
          break;

        case OMP_CLAUSE_DEVICE_RESIDENT:
        case OMP_CLAUSE_USE_DEVICE:
        case OMP_CLAUSE__CACHE_:
        case OMP_CLAUSE_INDEPENDENT:
        case OMP_CLAUSE_AUTO:
        case OMP_CLAUSE_SEQ:
          sorry ("Clause not supported yet");
          break;

        default:
          gcc_unreachable ();
        }
    }

  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
    {
      switch (OMP_CLAUSE_CODE (c))
        {
        case OMP_CLAUSE_LASTPRIVATE:
          /* Let the corresponding firstprivate clause create
             the variable.  */
          if (OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c))
            scan_array_reductions = true;
          if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
            break;
          /* FALLTHRU */

        case OMP_CLAUSE_FIRSTPRIVATE:
          if (is_gimple_omp_oacc (ctx->stmt))
            {
              sorry ("clause not supported yet");
              break;
            }
          /* FALLTHRU */
        case OMP_CLAUSE_PRIVATE:
        case OMP_CLAUSE_REDUCTION:
        case OMP_CLAUSE_LINEAR:
          decl = OMP_CLAUSE_DECL (c);
          if (is_variable_sized (decl))
            install_var_local (decl, ctx);
          fixup_remapped_decl (decl, ctx,
                               OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
                               && OMP_CLAUSE_PRIVATE_DEBUG (c));
          if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
              && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
            scan_array_reductions = true;
          else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR
                   && OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c))
            scan_array_reductions = true;
          break;

        case OMP_CLAUSE_SHARED:
          /* Ignore shared directives in teams construct.  */
          if (gimple_code (ctx->stmt) == GIMPLE_OMP_TEAMS)
            break;
          decl = OMP_CLAUSE_DECL (c);
          if (! is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx)))
            fixup_remapped_decl (decl, ctx, false);
          break;

        case OMP_CLAUSE_MAP:
          if (!is_gimple_omp_offloaded (ctx->stmt))
            break;
          decl = OMP_CLAUSE_DECL (c);
          if (DECL_P (decl)
              && is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx))
              && varpool_node::get_create (decl)->offloadable)
            break;
          if (DECL_P (decl))
            {
              if (OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
                  && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
                  && !COMPLETE_TYPE_P (TREE_TYPE (decl)))
                {
                  tree new_decl = lookup_decl (decl, ctx);
                  TREE_TYPE (new_decl)
                    = remap_type (TREE_TYPE (decl), &ctx->cb);
                }
              else if (DECL_SIZE (decl)
                       && TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
                {
                  tree decl2 = DECL_VALUE_EXPR (decl);
                  gcc_assert (TREE_CODE (decl2) == INDIRECT_REF);
                  decl2 = TREE_OPERAND (decl2, 0);
                  gcc_assert (DECL_P (decl2));
                  fixup_remapped_decl (decl2, ctx, false);
                  fixup_remapped_decl (decl, ctx, true);
                }
              else
                fixup_remapped_decl (decl, ctx, false);
            }
          break;

        case OMP_CLAUSE_COPYPRIVATE:
        case OMP_CLAUSE_COPYIN:
        case OMP_CLAUSE_DEFAULT:
        case OMP_CLAUSE_IF:
        case OMP_CLAUSE_NUM_THREADS:
        case OMP_CLAUSE_NUM_TEAMS:
        case OMP_CLAUSE_THREAD_LIMIT:
        case OMP_CLAUSE_DEVICE:
        case OMP_CLAUSE_SCHEDULE:
        case OMP_CLAUSE_DIST_SCHEDULE:
        case OMP_CLAUSE_NOWAIT:
        case OMP_CLAUSE_ORDERED:
        case OMP_CLAUSE_COLLAPSE:
        case OMP_CLAUSE_UNTIED:
        case OMP_CLAUSE_FINAL:
        case OMP_CLAUSE_MERGEABLE:
        case OMP_CLAUSE_PROC_BIND:
        case OMP_CLAUSE_SAFELEN:
        case OMP_CLAUSE_ALIGNED:
        case OMP_CLAUSE_DEPEND:
        case OMP_CLAUSE__LOOPTEMP_:
        case OMP_CLAUSE_TO:
        case OMP_CLAUSE_FROM:
        case OMP_CLAUSE__CILK_FOR_COUNT_:
        case OMP_CLAUSE_ASYNC:
        case OMP_CLAUSE_WAIT:
        case OMP_CLAUSE_NUM_GANGS:
        case OMP_CLAUSE_NUM_WORKERS:
        case OMP_CLAUSE_VECTOR_LENGTH:
        case OMP_CLAUSE_GANG:
        case OMP_CLAUSE_WORKER:
        case OMP_CLAUSE_VECTOR:
          break;

        case OMP_CLAUSE_DEVICE_RESIDENT:
        case OMP_CLAUSE_USE_DEVICE:
        case OMP_CLAUSE__CACHE_:
        case OMP_CLAUSE_INDEPENDENT:
        case OMP_CLAUSE_AUTO:
        case OMP_CLAUSE_SEQ:
          sorry ("Clause not supported yet");
          break;

        default:
          gcc_unreachable ();
        }
    }

  gcc_checking_assert (!scan_array_reductions
                       || !is_gimple_omp_oacc (ctx->stmt));
  if (scan_array_reductions)
    for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
          && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
        {
          scan_omp (&OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c), ctx);
          scan_omp (&OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c), ctx);
        }
      else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE
               && OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c))
        scan_omp (&OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c), ctx);
      else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR
               && OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c))
        scan_omp (&OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c), ctx);
}

/* Create a new name for omp child function.  Returns an identifier.  If
   IS_CILK_FOR is true then the suffix for the child function is
   "_cilk_for_fn."  */

static tree
create_omp_child_function_name (bool task_copy, bool is_cilk_for)
{
  if (is_cilk_for)
    return clone_function_name (current_function_decl, "_cilk_for_fn");
  return clone_function_name (current_function_decl,
                              task_copy ? "_omp_cpyfn" : "_omp_fn");
}

/* Returns the type of the induction variable for the child function for
   _Cilk_for and the types for _high and _low variables based on TYPE.  */

static tree
cilk_for_check_loop_diff_type (tree type)
{
  if (TYPE_PRECISION (type) <= TYPE_PRECISION (uint32_type_node))
    {
      if (TYPE_UNSIGNED (type))
        return uint32_type_node;
      else
        return integer_type_node;
    }
  else
    {
      if (TYPE_UNSIGNED (type))
        return uint64_type_node;
      else
        return long_long_integer_type_node;
    }
}

/* Build a decl for the omp child function.  It'll not contain a body
   yet, just the bare decl.  */

static void
create_omp_child_function (omp_context *ctx, bool task_copy)
{
  tree decl, type, name, t;

  tree cilk_for_count
    = (flag_cilkplus && gimple_code (ctx->stmt) == GIMPLE_OMP_PARALLEL)
      ? find_omp_clause (gimple_omp_parallel_clauses (ctx->stmt),
                         OMP_CLAUSE__CILK_FOR_COUNT_) : NULL_TREE;
  tree cilk_var_type = NULL_TREE;

  name = create_omp_child_function_name (task_copy,
                                         cilk_for_count != NULL_TREE);
  if (task_copy)
    type = build_function_type_list (void_type_node, ptr_type_node,
                                     ptr_type_node, NULL_TREE);
  else if (cilk_for_count)
    {
      type = TREE_TYPE (OMP_CLAUSE_OPERAND (cilk_for_count, 0));
      cilk_var_type = cilk_for_check_loop_diff_type (type);
      type = build_function_type_list (void_type_node, ptr_type_node,
                                       cilk_var_type, cilk_var_type, NULL_TREE);
    }
  else
    type = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);

  decl = build_decl (gimple_location (ctx->stmt), FUNCTION_DECL, name, type);

  gcc_checking_assert (!is_gimple_omp_oacc (ctx->stmt)
                       || !task_copy);
  if (!task_copy)
    ctx->cb.dst_fn = decl;
  else
    gimple_omp_task_set_copy_fn (ctx->stmt, decl);

  TREE_STATIC (decl) = 1;
  TREE_USED (decl) = 1;
  DECL_ARTIFICIAL (decl) = 1;
  DECL_IGNORED_P (decl) = 0;
  TREE_PUBLIC (decl) = 0;
  DECL_UNINLINABLE (decl) = 1;
  DECL_EXTERNAL (decl) = 0;
  DECL_CONTEXT (decl) = NULL_TREE;
  DECL_INITIAL (decl) = make_node (BLOCK);
  if (cgraph_node::get (current_function_decl)->offloadable)
    cgraph_node::get_create (decl)->offloadable = 1;
  else
    {
      omp_context *octx;
      for (octx = ctx; octx; octx = octx->outer)
        if (is_gimple_omp_offloaded (octx->stmt))
          {
            cgraph_node::get_create (decl)->offloadable = 1;
#ifdef ENABLE_OFFLOADING
            g->have_offload = true;
#endif
            break;
          }
    }

  if (cgraph_node::get_create (decl)->offloadable
      && !lookup_attribute ("omp declare target",
                           DECL_ATTRIBUTES (current_function_decl)))
    DECL_ATTRIBUTES (decl)
      = tree_cons (get_identifier ("omp target entrypoint"),
                   NULL_TREE, DECL_ATTRIBUTES (decl));

  t = build_decl (DECL_SOURCE_LOCATION (decl),
                  RESULT_DECL, NULL_TREE, void_type_node);
  DECL_ARTIFICIAL (t) = 1;
  DECL_IGNORED_P (t) = 1;
  DECL_CONTEXT (t) = decl;
  DECL_RESULT (decl) = t;

  /* _Cilk_for's child function requires two extra parameters called
     __low and __high that are set the by Cilk runtime when it calls this
     function.  */
  if (cilk_for_count)
    {
      t = build_decl (DECL_SOURCE_LOCATION (decl),
                      PARM_DECL, get_identifier ("__high"), cilk_var_type);
      DECL_ARTIFICIAL (t) = 1;
      DECL_NAMELESS (t) = 1;
      DECL_ARG_TYPE (t) = ptr_type_node;
      DECL_CONTEXT (t) = current_function_decl;
      TREE_USED (t) = 1;
      DECL_CHAIN (t) = DECL_ARGUMENTS (decl);
      DECL_ARGUMENTS (decl) = t;

      t = build_decl (DECL_SOURCE_LOCATION (decl),
                      PARM_DECL, get_identifier ("__low"), cilk_var_type);
      DECL_ARTIFICIAL (t) = 1;
      DECL_NAMELESS (t) = 1;
      DECL_ARG_TYPE (t) = ptr_type_node;
      DECL_CONTEXT (t) = current_function_decl;
      TREE_USED (t) = 1;
      DECL_CHAIN (t) = DECL_ARGUMENTS (decl);
      DECL_ARGUMENTS (decl) = t;
    }

  tree data_name = get_identifier (".omp_data_i");
  t = build_decl (DECL_SOURCE_LOCATION (decl), PARM_DECL, data_name,
                  ptr_type_node);
  DECL_ARTIFICIAL (t) = 1;
  DECL_NAMELESS (t) = 1;
  DECL_ARG_TYPE (t) = ptr_type_node;
  DECL_CONTEXT (t) = current_function_decl;
  TREE_USED (t) = 1;
  if (cilk_for_count)
    DECL_CHAIN (t) = DECL_ARGUMENTS (decl);
  DECL_ARGUMENTS (decl) = t;
  if (!task_copy)
    ctx->receiver_decl = t;
  else
    {
      t = build_decl (DECL_SOURCE_LOCATION (decl),
                      PARM_DECL, get_identifier (".omp_data_o"),
                      ptr_type_node);
      DECL_ARTIFICIAL (t) = 1;
      DECL_NAMELESS (t) = 1;
      DECL_ARG_TYPE (t) = ptr_type_node;
      DECL_CONTEXT (t) = current_function_decl;
      TREE_USED (t) = 1;
      TREE_ADDRESSABLE (t) = 1;
      DECL_CHAIN (t) = DECL_ARGUMENTS (decl);
      DECL_ARGUMENTS (decl) = t;
    }

  /* Allocate memory for the function structure.  The call to
     allocate_struct_function clobbers CFUN, so we need to restore
     it afterward.  */
  push_struct_function (decl);
  cfun->function_end_locus = gimple_location (ctx->stmt);
  pop_cfun ();
}

/* Callback for walk_gimple_seq.  Check if combined parallel
   contains gimple_omp_for_combined_into_p OMP_FOR.  */

static tree
find_combined_for (gimple_stmt_iterator *gsi_p,
                   bool *handled_ops_p,
                   struct walk_stmt_info *wi)
{
  gimple stmt = gsi_stmt (*gsi_p);

  *handled_ops_p = true;
  switch (gimple_code (stmt))
    {
    WALK_SUBSTMTS;

    case GIMPLE_OMP_FOR:
      if (gimple_omp_for_combined_into_p (stmt)
          && gimple_omp_for_kind (stmt) == GF_OMP_FOR_KIND_FOR)
        {
          wi->info = stmt;
          return integer_zero_node;
        }
      break;
    default:
      break;
    }
  return NULL;
}

/* Scan an OpenMP parallel directive.  */

static void
scan_omp_parallel (gimple_stmt_iterator *gsi, omp_context *outer_ctx)
{
  omp_context *ctx;
  tree name;
  gomp_parallel *stmt = as_a <gomp_parallel *> (gsi_stmt (*gsi));

  /* Ignore parallel directives with empty bodies, unless there
     are copyin clauses.  */
  if (optimize > 0
      && empty_body_p (gimple_omp_body (stmt))
      && find_omp_clause (gimple_omp_parallel_clauses (stmt),
                          OMP_CLAUSE_COPYIN) == NULL)
    {
      gsi_replace (gsi, gimple_build_nop (), false);
      return;
    }

  if (gimple_omp_parallel_combined_p (stmt))
    {
      struct walk_stmt_info wi;

      memset (&wi, 0, sizeof (wi));
      wi.val_only = true;
      walk_gimple_seq (gimple_omp_body (stmt),
                       find_combined_for, NULL, &wi);
      if (wi.info)
        {
          gomp_for *for_stmt = as_a <gomp_for *> ((gimple) wi.info);
          struct omp_for_data fd;
          extract_omp_for_data (for_stmt, &fd, NULL);
          /* We need two temporaries with fd.loop.v type (istart/iend)
             and then (fd.collapse - 1) temporaries with the same
             type for count2 ... countN-1 vars if not constant.  */
          size_t count = 2, i;
          tree type = fd.iter_type;
          if (fd.collapse > 1
              && TREE_CODE (fd.loop.n2) != INTEGER_CST)
            count += fd.collapse - 1;
          for (i = 0; i < count; i++)
            {
              tree temp = create_tmp_var (type);
              tree c = build_omp_clause (UNKNOWN_LOCATION,
                                         OMP_CLAUSE__LOOPTEMP_);
              insert_decl_map (&outer_ctx->cb, temp, temp);
              OMP_CLAUSE_DECL (c) = temp;
              OMP_CLAUSE_CHAIN (c) = gimple_omp_parallel_clauses (stmt);
              gimple_omp_parallel_set_clauses (stmt, c);
            }
        }
    }

  ctx = new_omp_context (stmt, outer_ctx);
  taskreg_contexts.safe_push (ctx);
  if (taskreg_nesting_level > 1)
    ctx->is_nested = true;
  ctx->field_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
  ctx->default_kind = OMP_CLAUSE_DEFAULT_SHARED;
  ctx->record_type = lang_hooks.types.make_type (RECORD_TYPE);
  name = create_tmp_var_name (".omp_data_s");
  name = build_decl (gimple_location (stmt),
                     TYPE_DECL, name, ctx->record_type);
  DECL_ARTIFICIAL (name) = 1;
  DECL_NAMELESS (name) = 1;
  TYPE_NAME (ctx->record_type) = name;
  TYPE_ARTIFICIAL (ctx->record_type) = 1;
  create_omp_child_function (ctx, false);
  gimple_omp_parallel_set_child_fn (stmt, ctx->cb.dst_fn);

  scan_sharing_clauses (gimple_omp_parallel_clauses (stmt), ctx);
  scan_omp (gimple_omp_body_ptr (stmt), ctx);

  if (TYPE_FIELDS (ctx->record_type) == NULL)
    ctx->record_type = ctx->receiver_decl = NULL;
}

/* Scan an OpenMP task directive.  */

static void
scan_omp_task (gimple_stmt_iterator *gsi, omp_context *outer_ctx)
{
  omp_context *ctx;
  tree name, t;
  gomp_task *stmt = as_a <gomp_task *> (gsi_stmt (*gsi));

  /* Ignore task directives with empty bodies.  */
  if (optimize > 0
      && empty_body_p (gimple_omp_body (stmt)))
    {
      gsi_replace (gsi, gimple_build_nop (), false);
      return;
    }

  ctx = new_omp_context (stmt, outer_ctx);
  taskreg_contexts.safe_push (ctx);
  if (taskreg_nesting_level > 1)
    ctx->is_nested = true;
  ctx->field_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
  ctx->default_kind = OMP_CLAUSE_DEFAULT_SHARED;
  ctx->record_type = lang_hooks.types.make_type (RECORD_TYPE);
  name = create_tmp_var_name (".omp_data_s");
  name = build_decl (gimple_location (stmt),
                     TYPE_DECL, name, ctx->record_type);
  DECL_ARTIFICIAL (name) = 1;
  DECL_NAMELESS (name) = 1;
  TYPE_NAME (ctx->record_type) = name;
  TYPE_ARTIFICIAL (ctx->record_type) = 1;
  create_omp_child_function (ctx, false);
  gimple_omp_task_set_child_fn (stmt, ctx->cb.dst_fn);

  scan_sharing_clauses (gimple_omp_task_clauses (stmt), ctx);

  if (ctx->srecord_type)
    {
      name = create_tmp_var_name (".omp_data_a");
      name = build_decl (gimple_location (stmt),
                         TYPE_DECL, name, ctx->srecord_type);
      DECL_ARTIFICIAL (name) = 1;
      DECL_NAMELESS (name) = 1;
      TYPE_NAME (ctx->srecord_type) = name;
      TYPE_ARTIFICIAL (ctx->srecord_type) = 1;
      create_omp_child_function (ctx, true);
    }

  scan_omp (gimple_omp_body_ptr (stmt), ctx);

  if (TYPE_FIELDS (ctx->record_type) == NULL)
    {
      ctx->record_type = ctx->receiver_decl = NULL;
      t = build_int_cst (long_integer_type_node, 0);
      gimple_omp_task_set_arg_size (stmt, t);
      t = build_int_cst (long_integer_type_node, 1);
      gimple_omp_task_set_arg_align (stmt, t);
    }
}


/* If any decls have been made addressable during scan_omp,
   adjust their fields if needed, and layout record types
   of parallel/task constructs.  */

static void
finish_taskreg_scan (omp_context *ctx)
{
  if (ctx->record_type == NULL_TREE)
    return;

  /* If any task_shared_vars were needed, verify all
     OMP_CLAUSE_SHARED clauses on GIMPLE_OMP_{PARALLEL,TASK}
     statements if use_pointer_for_field hasn't changed
     because of that.  If it did, update field types now.  */
  if (task_shared_vars)
    {
      tree c;

      for (c = gimple_omp_taskreg_clauses (ctx->stmt);
           c; c = OMP_CLAUSE_CHAIN (c))
        if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_SHARED)
          {
            tree decl = OMP_CLAUSE_DECL (c);

            /* Global variables don't need to be copied,
               the receiver side will use them directly.  */
            if (is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx)))
              continue;
            if (!bitmap_bit_p (task_shared_vars, DECL_UID (decl))
                || !use_pointer_for_field (decl, ctx))
              continue;
            tree field = lookup_field (decl, ctx);
            if (TREE_CODE (TREE_TYPE (field)) == POINTER_TYPE
                && TREE_TYPE (TREE_TYPE (field)) == TREE_TYPE (decl))
              continue;
            TREE_TYPE (field) = build_pointer_type (TREE_TYPE (decl));
            TREE_THIS_VOLATILE (field) = 0;
            DECL_USER_ALIGN (field) = 0;
            DECL_ALIGN (field) = TYPE_ALIGN (TREE_TYPE (field));
            if (TYPE_ALIGN (ctx->record_type) < DECL_ALIGN (field))
              TYPE_ALIGN (ctx->record_type) = DECL_ALIGN (field);
            if (ctx->srecord_type)
              {
                tree sfield = lookup_sfield (decl, ctx);
                TREE_TYPE (sfield) = TREE_TYPE (field);
                TREE_THIS_VOLATILE (sfield) = 0;
                DECL_USER_ALIGN (sfield) = 0;
                DECL_ALIGN (sfield) = DECL_ALIGN (field);
                if (TYPE_ALIGN (ctx->srecord_type) < DECL_ALIGN (sfield))
                  TYPE_ALIGN (ctx->srecord_type) = DECL_ALIGN (sfield);
              }
          }
    }

  if (gimple_code (ctx->stmt) == GIMPLE_OMP_PARALLEL)
    {
      layout_type (ctx->record_type);
      fixup_child_record_type (ctx);
    }
  else
    {
      location_t loc = gimple_location (ctx->stmt);
      tree *p, vla_fields = NULL_TREE, *q = &vla_fields;
      /* Move VLA fields to the end.  */
      p = &TYPE_FIELDS (ctx->record_type);
      while (*p)
        if (!TYPE_SIZE_UNIT (TREE_TYPE (*p))
            || ! TREE_CONSTANT (TYPE_SIZE_UNIT (TREE_TYPE (*p))))
          {
            *q = *p;
            *p = TREE_CHAIN (*p);
            TREE_CHAIN (*q) = NULL_TREE;
            q = &TREE_CHAIN (*q);
          }
        else
          p = &DECL_CHAIN (*p);
      *p = vla_fields;
      layout_type (ctx->record_type);
      fixup_child_record_type (ctx);
      if (ctx->srecord_type)
        layout_type (ctx->srecord_type);
      tree t = fold_convert_loc (loc, long_integer_type_node,
                                 TYPE_SIZE_UNIT (ctx->record_type));
      gimple_omp_task_set_arg_size (ctx->stmt, t);
      t = build_int_cst (long_integer_type_node,
                         TYPE_ALIGN_UNIT (ctx->record_type));
      gimple_omp_task_set_arg_align (ctx->stmt, t);
    }
}


static omp_context *
enclosing_target_ctx (omp_context *ctx)
{
  while (ctx != NULL
         && gimple_code (ctx->stmt) != GIMPLE_OMP_TARGET)
    ctx = ctx->outer;
  gcc_assert (ctx != NULL);
  return ctx;
}

static bool
oacc_loop_or_target_p (gimple stmt)
{
  enum gimple_code outer_type = gimple_code (stmt);
  return ((outer_type == GIMPLE_OMP_TARGET
           && ((gimple_omp_target_kind (stmt)
                == GF_OMP_TARGET_KIND_OACC_PARALLEL)
               || (gimple_omp_target_kind (stmt)
                   == GF_OMP_TARGET_KIND_OACC_KERNELS)))
          || (outer_type == GIMPLE_OMP_FOR
              && gimple_omp_for_kind (stmt) == GF_OMP_FOR_KIND_OACC_LOOP));
}

/* Scan a GIMPLE_OMP_FOR.  */

static void
scan_omp_for (gomp_for *stmt, omp_context *outer_ctx)
{
  enum gimple_code outer_type = GIMPLE_ERROR_MARK;
  omp_context *ctx;
  size_t i;
  tree clauses = gimple_omp_for_clauses (stmt);

  if (outer_ctx)
    outer_type = gimple_code (outer_ctx->stmt);

  ctx = new_omp_context (stmt, outer_ctx);

  if (is_gimple_omp_oacc (stmt))
    {
      if (outer_ctx && outer_type == GIMPLE_OMP_FOR)
        ctx->gwv_this = outer_ctx->gwv_this;
      for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
        {
          int val;
          if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_GANG)
            val = MASK_GANG;
          else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_WORKER)
            val = MASK_WORKER;
          else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_VECTOR)
            val = MASK_VECTOR;
          else
            continue;
          ctx->gwv_this |= val;
          if (!outer_ctx)
            {
              /* Skip; not nested inside a region.  */
              continue;
            }
          if (!oacc_loop_or_target_p (outer_ctx->stmt))
            {
              /* Skip; not nested inside an OpenACC region.  */
              continue;
            }
          if (outer_type == GIMPLE_OMP_FOR)
            outer_ctx->gwv_below |= val;
          if (OMP_CLAUSE_OPERAND (c, 0) != NULL_TREE)
            {
              omp_context *enclosing = enclosing_target_ctx (outer_ctx);
              if (gimple_omp_target_kind (enclosing->stmt)
                  == GF_OMP_TARGET_KIND_OACC_PARALLEL)
                error_at (gimple_location (stmt),
                          "no arguments allowed to gang, worker and vector clauses inside parallel");
            }
        }
    }

  scan_sharing_clauses (clauses, ctx);

  scan_omp (gimple_omp_for_pre_body_ptr (stmt), ctx);
  for (i = 0; i < gimple_omp_for_collapse (stmt); i++)
    {
      scan_omp_op (gimple_omp_for_index_ptr (stmt, i), ctx);
      scan_omp_op (gimple_omp_for_initial_ptr (stmt, i), ctx);
      scan_omp_op (gimple_omp_for_final_ptr (stmt, i), ctx);
      scan_omp_op (gimple_omp_for_incr_ptr (stmt, i), ctx);
    }
  scan_omp (gimple_omp_body_ptr (stmt), ctx);

  if (is_gimple_omp_oacc (stmt))
    {
      if (ctx->gwv_this & ctx->gwv_below)
        error_at (gimple_location (stmt),
                  "gang, worker and vector may occur only once in a loop nest");
      else if (ctx->gwv_below != 0
               && ctx->gwv_this > ctx->gwv_below)
        error_at (gimple_location (stmt),
                  "gang, worker and vector must occur in this order in a loop nest");
      if (outer_ctx && outer_type == GIMPLE_OMP_FOR)
        outer_ctx->gwv_below |= ctx->gwv_below;
    }
}

/* Scan an OpenMP sections directive.  */

static void
scan_omp_sections (gomp_sections *stmt, omp_context *outer_ctx)
{
  omp_context *ctx;

  ctx = new_omp_context (stmt, outer_ctx);
  scan_sharing_clauses (gimple_omp_sections_clauses (stmt), ctx);
  scan_omp (gimple_omp_body_ptr (stmt), ctx);
}

/* Scan an OpenMP single directive.  */

static void
scan_omp_single (gomp_single *stmt, omp_context *outer_ctx)
{
  omp_context *ctx;
  tree name;

  ctx = new_omp_context (stmt, outer_ctx);
  ctx->field_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
  ctx->record_type = lang_hooks.types.make_type (RECORD_TYPE);
  name = create_tmp_var_name (".omp_copy_s");
  name = build_decl (gimple_location (stmt),
                     TYPE_DECL, name, ctx->record_type);
  TYPE_NAME (ctx->record_type) = name;

  scan_sharing_clauses (gimple_omp_single_clauses (stmt), ctx);
  scan_omp (gimple_omp_body_ptr (stmt), ctx);

  if (TYPE_FIELDS (ctx->record_type) == NULL)
    ctx->record_type = NULL;
  else
    layout_type (ctx->record_type);
}

/* Scan a GIMPLE_OMP_TARGET.  */

static void
scan_omp_target (gomp_target *stmt, omp_context *outer_ctx)
{
  omp_context *ctx;
  tree name;
  bool offloaded = is_gimple_omp_offloaded (stmt);
  tree clauses = gimple_omp_target_clauses (stmt);

  ctx = new_omp_context (stmt, outer_ctx);
  ctx->field_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
  ctx->default_kind = OMP_CLAUSE_DEFAULT_SHARED;
  ctx->record_type = lang_hooks.types.make_type (RECORD_TYPE);
  name = create_tmp_var_name (".omp_data_t");
  name = build_decl (gimple_location (stmt),
                     TYPE_DECL, name, ctx->record_type);
  DECL_ARTIFICIAL (name) = 1;
  DECL_NAMELESS (name) = 1;
  TYPE_NAME (ctx->record_type) = name;
  TYPE_ARTIFICIAL (ctx->record_type) = 1;
  if (offloaded)
    {
      if (is_gimple_omp_oacc (stmt))
        ctx->reduction_map = splay_tree_new (splay_tree_compare_pointers,
                                             0, 0);

      create_omp_child_function (ctx, false);
      gimple_omp_target_set_child_fn (stmt, ctx->cb.dst_fn);
    }

  if (is_gimple_omp_oacc (stmt))
    {
      for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
        {
          if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_NUM_GANGS)
            ctx->gwv_this |= MASK_GANG;
          else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_NUM_WORKERS)
            ctx->gwv_this |= MASK_WORKER;
          else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_VECTOR_LENGTH)
            ctx->gwv_this |= MASK_VECTOR;
        }
    }

  scan_sharing_clauses (clauses, ctx);
  scan_omp (gimple_omp_body_ptr (stmt), ctx);

  if (TYPE_FIELDS (ctx->record_type) == NULL)
    ctx->record_type = ctx->receiver_decl = NULL;
  else
    {
      TYPE_FIELDS (ctx->record_type)
        = nreverse (TYPE_FIELDS (ctx->record_type));
#ifdef ENABLE_CHECKING
      tree field;
      unsigned int align = DECL_ALIGN (TYPE_FIELDS (ctx->record_type));
      for (field = TYPE_FIELDS (ctx->record_type);
           field;
           field = DECL_CHAIN (field))
        gcc_assert (DECL_ALIGN (field) == align);
#endif
      layout_type (ctx->record_type);
      if (offloaded)
        fixup_child_record_type (ctx);
    }
}

/* Scan an OpenMP teams directive.  */

static void
scan_omp_teams (gomp_teams *stmt, omp_context *outer_ctx)
{
  omp_context *ctx = new_omp_context (stmt, outer_ctx);
  scan_sharing_clauses (gimple_omp_teams_clauses (stmt), ctx);
  scan_omp (gimple_omp_body_ptr (stmt), ctx);
}

/* Check nesting restrictions.  */
static bool
check_omp_nesting_restrictions (gimple stmt, omp_context *ctx)
{
  /* No nesting of non-OpenACC STMT (that is, an OpenMP one, or a GOMP builtin)
     inside an OpenACC CTX.  */
  if (!(is_gimple_omp (stmt)
        && is_gimple_omp_oacc (stmt)))
    {
      for (omp_context *ctx_ = ctx; ctx_ != NULL; ctx_ = ctx_->outer)
        if (is_gimple_omp (ctx_->stmt)
            && is_gimple_omp_oacc (ctx_->stmt))
          {
            error_at (gimple_location (stmt),
                      "non-OpenACC construct inside of OpenACC region");
            return false;
          }
    }

  if (ctx != NULL)
    {
      if (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR
          && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD)
        {
          error_at (gimple_location (stmt),
                    "OpenMP constructs may not be nested inside simd region");
          return false;
        }
      else if (gimple_code (ctx->stmt) == GIMPLE_OMP_TEAMS)
        {
          if ((gimple_code (stmt) != GIMPLE_OMP_FOR
               || (gimple_omp_for_kind (stmt)
                   != GF_OMP_FOR_KIND_DISTRIBUTE))
              && gimple_code (stmt) != GIMPLE_OMP_PARALLEL)
            {
              error_at (gimple_location (stmt),
                        "only distribute or parallel constructs are allowed to "
                        "be closely nested inside teams construct");
              return false;
            }
        }
    }
  switch (gimple_code (stmt))
    {
    case GIMPLE_OMP_FOR:
      if (gimple_omp_for_kind (stmt) & GF_OMP_FOR_SIMD)
        return true;
      if (gimple_omp_for_kind (stmt) == GF_OMP_FOR_KIND_DISTRIBUTE)
        {
          if (ctx != NULL && gimple_code (ctx->stmt) != GIMPLE_OMP_TEAMS)
            {
              error_at (gimple_location (stmt),
                        "distribute construct must be closely nested inside "
                        "teams construct");
              return false;
            }
          return true;
        }
      /* FALLTHRU */
    case GIMPLE_CALL:
      if (is_gimple_call (stmt)
          && (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
              == BUILT_IN_GOMP_CANCEL
              || DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                 == BUILT_IN_GOMP_CANCELLATION_POINT))
        {
          const char *bad = NULL;
          const char *kind = NULL;
          if (ctx == NULL)
            {
              error_at (gimple_location (stmt), "orphaned %qs construct",
                        DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                        == BUILT_IN_GOMP_CANCEL
                        ? "#pragma omp cancel"
                        : "#pragma omp cancellation point");
              return false;
            }
          switch (tree_fits_shwi_p (gimple_call_arg (stmt, 0))
                  ? tree_to_shwi (gimple_call_arg (stmt, 0))
                  : 0)
            {
            case 1:
              if (gimple_code (ctx->stmt) != GIMPLE_OMP_PARALLEL)
                bad = "#pragma omp parallel";
              else if (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                       == BUILT_IN_GOMP_CANCEL
                       && !integer_zerop (gimple_call_arg (stmt, 1)))
                ctx->cancellable = true;
              kind = "parallel";
              break;
            case 2:
              if (gimple_code (ctx->stmt) != GIMPLE_OMP_FOR
                  || gimple_omp_for_kind (ctx->stmt) != GF_OMP_FOR_KIND_FOR)
                bad = "#pragma omp for";
              else if (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                       == BUILT_IN_GOMP_CANCEL
                       && !integer_zerop (gimple_call_arg (stmt, 1)))
                {
                  ctx->cancellable = true;
                  if (find_omp_clause (gimple_omp_for_clauses (ctx->stmt),
                                       OMP_CLAUSE_NOWAIT))
                    warning_at (gimple_location (stmt), 0,
                                "%<#pragma omp cancel for%> inside "
                                "%<nowait%> for construct");
                  if (find_omp_clause (gimple_omp_for_clauses (ctx->stmt),
                                       OMP_CLAUSE_ORDERED))
                    warning_at (gimple_location (stmt), 0,
                                "%<#pragma omp cancel for%> inside "
                                "%<ordered%> for construct");
                }
              kind = "for";
              break;
            case 4:
              if (gimple_code (ctx->stmt) != GIMPLE_OMP_SECTIONS
                  && gimple_code (ctx->stmt) != GIMPLE_OMP_SECTION)
                bad = "#pragma omp sections";
              else if (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                       == BUILT_IN_GOMP_CANCEL
                       && !integer_zerop (gimple_call_arg (stmt, 1)))
                {
                  if (gimple_code (ctx->stmt) == GIMPLE_OMP_SECTIONS)
                    {
                      ctx->cancellable = true;
                      if (find_omp_clause (gimple_omp_sections_clauses
                                                                (ctx->stmt),
                                           OMP_CLAUSE_NOWAIT))
                        warning_at (gimple_location (stmt), 0,
                                    "%<#pragma omp cancel sections%> inside "
                                    "%<nowait%> sections construct");
                    }
                  else
                    {
                      gcc_assert (ctx->outer
                                  && gimple_code (ctx->outer->stmt)
                                     == GIMPLE_OMP_SECTIONS);
                      ctx->outer->cancellable = true;
                      if (find_omp_clause (gimple_omp_sections_clauses
                                                        (ctx->outer->stmt),
                                           OMP_CLAUSE_NOWAIT))
                        warning_at (gimple_location (stmt), 0,
                                    "%<#pragma omp cancel sections%> inside "
                                    "%<nowait%> sections construct");
                    }
                }
              kind = "sections";
              break;
            case 8:
              if (gimple_code (ctx->stmt) != GIMPLE_OMP_TASK)
                bad = "#pragma omp task";
              else
                ctx->cancellable = true;
              kind = "taskgroup";
              break;
            default:
              error_at (gimple_location (stmt), "invalid arguments");
              return false;
            }
          if (bad)
            {
              error_at (gimple_location (stmt),
                        "%<%s %s%> construct not closely nested inside of %qs",
                        DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                        == BUILT_IN_GOMP_CANCEL
                        ? "#pragma omp cancel"
                        : "#pragma omp cancellation point", kind, bad);
              return false;
            }
        }
      /* FALLTHRU */
    case GIMPLE_OMP_SECTIONS:
    case GIMPLE_OMP_SINGLE:
      for (; ctx != NULL; ctx = ctx->outer)
        switch (gimple_code (ctx->stmt))
          {
          case GIMPLE_OMP_FOR:
          case GIMPLE_OMP_SECTIONS:
          case GIMPLE_OMP_SINGLE:
          case GIMPLE_OMP_ORDERED:
          case GIMPLE_OMP_MASTER:
          case GIMPLE_OMP_TASK:
          case GIMPLE_OMP_CRITICAL:
            if (is_gimple_call (stmt))
              {
                if (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))
                    != BUILT_IN_GOMP_BARRIER)
                  return true;
                error_at (gimple_location (stmt),
                          "barrier region may not be closely nested inside "
                          "of work-sharing, critical, ordered, master or "
                          "explicit task region");
                return false;
              }
            error_at (gimple_location (stmt),
                      "work-sharing region may not be closely nested inside "
                      "of work-sharing, critical, ordered, master or explicit "
                      "task region");
            return false;
          case GIMPLE_OMP_PARALLEL:
            return true;
          default:
            break;
          }
      break;
    case GIMPLE_OMP_MASTER:
      for (; ctx != NULL; ctx = ctx->outer)
        switch (gimple_code (ctx->stmt))
          {
          case GIMPLE_OMP_FOR:
          case GIMPLE_OMP_SECTIONS:
          case GIMPLE_OMP_SINGLE:
          case GIMPLE_OMP_TASK:
            error_at (gimple_location (stmt),
                      "master region may not be closely nested inside "
                      "of work-sharing or explicit task region");
            return false;
          case GIMPLE_OMP_PARALLEL:
            return true;
          default:
            break;
          }
      break;
    case GIMPLE_OMP_ORDERED:
      for (; ctx != NULL; ctx = ctx->outer)
        switch (gimple_code (ctx->stmt))
          {
          case GIMPLE_OMP_CRITICAL:
          case GIMPLE_OMP_TASK:
            error_at (gimple_location (stmt),
                      "ordered region may not be closely nested inside "
                      "of critical or explicit task region");
            return false;
          case GIMPLE_OMP_FOR:
            if (find_omp_clause (gimple_omp_for_clauses (ctx->stmt),
                                 OMP_CLAUSE_ORDERED) == NULL)
              {
                error_at (gimple_location (stmt),
                          "ordered region must be closely nested inside "
                          "a loop region with an ordered clause");
                return false;
              }
            return true;
          case GIMPLE_OMP_PARALLEL:
            error_at (gimple_location (stmt),
                      "ordered region must be closely nested inside "
                      "a loop region with an ordered clause");
            return false;
          default:
            break;
          }
      break;
    case GIMPLE_OMP_CRITICAL:
      {
        tree this_stmt_name
          = gimple_omp_critical_name (as_a <gomp_critical *> (stmt));
        for (; ctx != NULL; ctx = ctx->outer)
          if (gomp_critical *other_crit
                = dyn_cast <gomp_critical *> (ctx->stmt))
            if (this_stmt_name == gimple_omp_critical_name (other_crit))
              {
                error_at (gimple_location (stmt),
                          "critical region may not be nested inside a critical "
                          "region with the same name");
                return false;
              }
      }
      break;
    case GIMPLE_OMP_TEAMS:
      if (ctx == NULL
          || gimple_code (ctx->stmt) != GIMPLE_OMP_TARGET
          || gimple_omp_target_kind (ctx->stmt) != GF_OMP_TARGET_KIND_REGION)
        {
          error_at (gimple_location (stmt),
                    "teams construct not closely nested inside of target "
                    "region");
          return false;
        }
      break;
    case GIMPLE_OMP_TARGET:
      for (; ctx != NULL; ctx = ctx->outer)
        {
          if (gimple_code (ctx->stmt) != GIMPLE_OMP_TARGET)
            {
              if (is_gimple_omp (stmt)
                  && is_gimple_omp_oacc (stmt)
                  && is_gimple_omp (ctx->stmt))
                {
                  error_at (gimple_location (stmt),
                            "OpenACC construct inside of non-OpenACC region");
                  return false;
                }
              continue;
            }

          const char *stmt_name, *ctx_stmt_name;
          switch (gimple_omp_target_kind (stmt))
            {
            case GF_OMP_TARGET_KIND_REGION: stmt_name = "target"; break;
            case GF_OMP_TARGET_KIND_DATA: stmt_name = "target data"; break;
            case GF_OMP_TARGET_KIND_UPDATE: stmt_name = "target update"; break;
            case GF_OMP_TARGET_KIND_OACC_PARALLEL: stmt_name = "parallel"; break;
            case GF_OMP_TARGET_KIND_OACC_KERNELS: stmt_name = "kernels"; break;
            case GF_OMP_TARGET_KIND_OACC_DATA: stmt_name = "data"; break;
            case GF_OMP_TARGET_KIND_OACC_UPDATE: stmt_name = "update"; break;
            case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA: stmt_name = "enter/exit data"; break;
            default: gcc_unreachable ();
            }
          switch (gimple_omp_target_kind (ctx->stmt))
            {
            case GF_OMP_TARGET_KIND_REGION: ctx_stmt_name = "target"; break;
            case GF_OMP_TARGET_KIND_DATA: ctx_stmt_name = "target data"; break;
            case GF_OMP_TARGET_KIND_OACC_PARALLEL: ctx_stmt_name = "parallel"; break;
            case GF_OMP_TARGET_KIND_OACC_KERNELS: ctx_stmt_name = "kernels"; break;
            case GF_OMP_TARGET_KIND_OACC_DATA: ctx_stmt_name = "data"; break;
            default: gcc_unreachable ();
            }

          /* OpenACC/OpenMP mismatch?  */
          if (is_gimple_omp_oacc (stmt)
              != is_gimple_omp_oacc (ctx->stmt))
            {
              error_at (gimple_location (stmt),
                        "%s %s construct inside of %s %s region",
                        (is_gimple_omp_oacc (stmt)
                         ? "OpenACC" : "OpenMP"), stmt_name,
                        (is_gimple_omp_oacc (ctx->stmt)
                         ? "OpenACC" : "OpenMP"), ctx_stmt_name);
              return false;
            }
          if (is_gimple_omp_offloaded (ctx->stmt))
            {
              /* No GIMPLE_OMP_TARGET inside offloaded OpenACC CTX.  */
              if (is_gimple_omp_oacc (ctx->stmt))
                {
                  error_at (gimple_location (stmt),
                            "%s construct inside of %s region",
                            stmt_name, ctx_stmt_name);
                  return false;
                }
              else
                {
                  gcc_checking_assert (!is_gimple_omp_oacc (stmt));
                  warning_at (gimple_location (stmt), 0,
                              "%s construct inside of %s region",
                              stmt_name, ctx_stmt_name);
                }
            }
        }
      break;
    default:
      break;
    }
  return true;
}


/* Helper function scan_omp.

   Callback for walk_tree or operators in walk_gimple_stmt used to
   scan for OMP directives in TP.  */

static tree
scan_omp_1_op (tree *tp, int *walk_subtrees, void *data)
{
  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
  omp_context *ctx = (omp_context *) wi->info;
  tree t = *tp;

  switch (TREE_CODE (t))
    {
    case VAR_DECL:
    case PARM_DECL:
    case LABEL_DECL:
    case RESULT_DECL:
      if (ctx)
        *tp = remap_decl (t, &ctx->cb);
      break;

    default:
      if (ctx && TYPE_P (t))
        *tp = remap_type (t, &ctx->cb);
      else if (!DECL_P (t))
        {
          *walk_subtrees = 1;
          if (ctx)
            {
              tree tem = remap_type (TREE_TYPE (t), &ctx->cb);
              if (tem != TREE_TYPE (t))
                {
                  if (TREE_CODE (t) == INTEGER_CST)
                    *tp = wide_int_to_tree (tem, t);
                  else
                    TREE_TYPE (t) = tem;
                }
            }
        }
      break;
    }

  return NULL_TREE;
}

/* Return true if FNDECL is a setjmp or a longjmp.  */

static bool
setjmp_or_longjmp_p (const_tree fndecl)
{
  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
      && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SETJMP
          || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_LONGJMP))
    return true;

  tree declname = DECL_NAME (fndecl);
  if (!declname)
    return false;
  const char *name = IDENTIFIER_POINTER (declname);
  return !strcmp (name, "setjmp") || !strcmp (name, "longjmp");
}


/* Helper function for scan_omp.

   Callback for walk_gimple_stmt used to scan for OMP directives in
   the current statement in GSI.  */

static tree
scan_omp_1_stmt (gimple_stmt_iterator *gsi, bool *handled_ops_p,
                 struct walk_stmt_info *wi)
{
  gimple stmt = gsi_stmt (*gsi);
  omp_context *ctx = (omp_context *) wi->info;

  if (gimple_has_location (stmt))
    input_location = gimple_location (stmt);

  /* Check the nesting restrictions.  */
  bool remove = false;
  if (is_gimple_omp (stmt))
    remove = !check_omp_nesting_restrictions (stmt, ctx);
  else if (is_gimple_call (stmt))
    {
      tree fndecl = gimple_call_fndecl (stmt);
      if (fndecl)
        {
          if (setjmp_or_longjmp_p (fndecl)
              && ctx
              && gimple_code (ctx->stmt) == GIMPLE_OMP_FOR
              && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD)
            {
              remove = true;
              error_at (gimple_location (stmt),
                        "setjmp/longjmp inside simd construct");
            }
          else if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
            switch (DECL_FUNCTION_CODE (fndecl))
              {
              case BUILT_IN_GOMP_BARRIER:
              case BUILT_IN_GOMP_CANCEL:
              case BUILT_IN_GOMP_CANCELLATION_POINT:
              case BUILT_IN_GOMP_TASKYIELD:
              case BUILT_IN_GOMP_TASKWAIT:
              case BUILT_IN_GOMP_TASKGROUP_START:
              case BUILT_IN_GOMP_TASKGROUP_END:
                remove = !check_omp_nesting_restrictions (stmt, ctx);
                break;
              default:
                break;
              }
        }
    }
  if (remove)
    {
      stmt = gimple_build_nop ();
      gsi_replace (gsi, stmt, false);
    }

  *handled_ops_p = true;

  switch (gimple_code (stmt))
    {
    case GIMPLE_OMP_PARALLEL:
      taskreg_nesting_level++;
      scan_omp_parallel (gsi, ctx);
      taskreg_nesting_level--;
      break;

    case GIMPLE_OMP_TASK:
      taskreg_nesting_level++;
      scan_omp_task (gsi, ctx);
      taskreg_nesting_level--;
      break;

    case GIMPLE_OMP_FOR:
      scan_omp_for (as_a <gomp_for *> (stmt), ctx);
      break;

    case GIMPLE_OMP_SECTIONS:
      scan_omp_sections (as_a <gomp_sections *> (stmt), ctx);
      break;

    case GIMPLE_OMP_SINGLE:
      scan_omp_single (as_a <gomp_single *> (stmt), ctx);
      break;

    case GIMPLE_OMP_SECTION:
    case GIMPLE_OMP_MASTER:
    case GIMPLE_OMP_TASKGROUP:
    case GIMPLE_OMP_ORDERED:
    case GIMPLE_OMP_CRITICAL:
      ctx = new_omp_context (stmt, ctx);
      scan_omp (gimple_omp_body_ptr (stmt), ctx);
      break;

    case GIMPLE_OMP_TARGET:
      scan_omp_target (as_a <gomp_target *> (stmt), ctx);
      break;

    case GIMPLE_OMP_TEAMS:
      scan_omp_teams (as_a <gomp_teams *> (stmt), ctx);
      break;

    case GIMPLE_BIND:
      {
        tree var;

        *handled_ops_p = false;
        if (ctx)
          for (var = gimple_bind_vars (as_a <gbind *> (stmt));
               var ;
               var = DECL_CHAIN (var))
            insert_decl_map (&ctx->cb, var, var);
      }
      break;
    default:
      *handled_ops_p = false;
      break;
    }

  return NULL_TREE;
}


/* Scan all the statements starting at the current statement.  CTX
   contains context information about the OMP directives and
   clauses found during the scan.  */

static void
scan_omp (gimple_seq *body_p, omp_context *ctx)
{
  location_t saved_location;
  struct walk_stmt_info wi;

  memset (&wi, 0, sizeof (wi));
  wi.info = ctx;
  wi.want_locations = true;

  saved_location = input_location;
  walk_gimple_seq_mod (body_p, scan_omp_1_stmt, scan_omp_1_op, &wi);
  input_location = saved_location;
}
\f
/* Re-gimplification and code generation routines.  */

/* Build a call to GOMP_barrier.  */

static gimple
build_omp_barrier (tree lhs)
{
  tree fndecl = builtin_decl_explicit (lhs ? BUILT_IN_GOMP_BARRIER_CANCEL
                                           : BUILT_IN_GOMP_BARRIER);
  gcall *g = gimple_build_call (fndecl, 0);
  if (lhs)
    gimple_call_set_lhs (g, lhs);
  return g;
}

/* If a context was created for STMT when it was scanned, return it.  */

static omp_context *
maybe_lookup_ctx (gimple stmt)
{
  splay_tree_node n;
  n = splay_tree_lookup (all_contexts, (splay_tree_key) stmt);
  return n ? (omp_context *) n->value : NULL;
}


/* Find the mapping for DECL in CTX or the immediately enclosing
   context that has a mapping for DECL.

   If CTX is a nested parallel directive, we may have to use the decl
   mappings created in CTX's parent context.  Suppose that we have the
   following parallel nesting (variable UIDs showed for clarity):

        iD.1562 = 0;
        #omp parallel shared(iD.1562)           -> outer parallel
          iD.1562 = iD.1562 + 1;

          #omp parallel shared (iD.1562)        -> inner parallel
             iD.1562 = iD.1562 - 1;

   Each parallel structure will create a distinct .omp_data_s structure
   for copying iD.1562 in/out of the directive:

        outer parallel          .omp_data_s.1.i -> iD.1562
        inner parallel          .omp_data_s.2.i -> iD.1562

   A shared variable mapping will produce a copy-out operation before
   the parallel directive and a copy-in operation after it.  So, in
   this case we would have:

        iD.1562 = 0;
        .omp_data_o.1.i = iD.1562;
        #omp parallel shared(iD.1562)           -> outer parallel
          .omp_data_i.1 = &.omp_data_o.1
          .omp_data_i.1->i = .omp_data_i.1->i + 1;

          .omp_data_o.2.i = iD.1562;            -> **
          #omp parallel shared(iD.1562)         -> inner parallel
            .omp_data_i.2 = &.omp_data_o.2
            .omp_data_i.2->i = .omp_data_i.2->i - 1;


    ** This is a problem.  The symbol iD.1562 cannot be referenced
       inside the body of the outer parallel region.  But since we are
       emitting this copy operation while expanding the inner parallel
       directive, we need to access the CTX structure of the outer
       parallel directive to get the correct mapping:

          .omp_data_o.2.i = .omp_data_i.1->i

    Since there may be other workshare or parallel directives enclosing
    the parallel directive, it may be necessary to walk up the context
    parent chain.  This is not a problem in general because nested
    parallelism happens only rarely.  */

static tree
lookup_decl_in_outer_ctx (tree decl, omp_context *ctx)
{
  tree t;
  omp_context *up;

  for (up = ctx->outer, t = NULL; up && t == NULL; up = up->outer)
    t = maybe_lookup_decl (decl, up);

  gcc_assert (!ctx->is_nested || t || is_global_var (decl));

  return t ? t : decl;
}


/* Similar to lookup_decl_in_outer_ctx, but return DECL if not found
   in outer contexts.  */

static tree
maybe_lookup_decl_in_outer_ctx (tree decl, omp_context *ctx)
{
  tree t = NULL;
  omp_context *up;

  for (up = ctx->outer, t = NULL; up && t == NULL; up = up->outer)
    t = maybe_lookup_decl (decl, up);

  return t ? t : decl;
}


/* Construct the initialization value for reduction CLAUSE.  */

tree
omp_reduction_init (tree clause, tree type)
{
  location_t loc = OMP_CLAUSE_LOCATION (clause);
  switch (OMP_CLAUSE_REDUCTION_CODE (clause))
    {
    case PLUS_EXPR:
    case MINUS_EXPR:
    case BIT_IOR_EXPR:
    case BIT_XOR_EXPR:
    case TRUTH_OR_EXPR:
    case TRUTH_ORIF_EXPR:
    case TRUTH_XOR_EXPR:
    case NE_EXPR:
      return build_zero_cst (type);

    case MULT_EXPR:
    case TRUTH_AND_EXPR:
    case TRUTH_ANDIF_EXPR:
    case EQ_EXPR:
      return fold_convert_loc (loc, type, integer_one_node);

    case BIT_AND_EXPR:
      return fold_convert_loc (loc, type, integer_minus_one_node);

    case MAX_EXPR:
      if (SCALAR_FLOAT_TYPE_P (type))
        {
          REAL_VALUE_TYPE max, min;
          if (HONOR_INFINITIES (type))
            {
              real_inf (&max);
              real_arithmetic (&min, NEGATE_EXPR, &max, NULL);
            }
          else
            real_maxval (&min, 1, TYPE_MODE (type));
          return build_real (type, min);
        }
      else if (POINTER_TYPE_P (type))
        {
          wide_int min
            = wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type));
          return wide_int_to_tree (type, min);
        }
      else
        {
          gcc_assert (INTEGRAL_TYPE_P (type));
          return TYPE_MIN_VALUE (type);
        }

    case MIN_EXPR:
      if (SCALAR_FLOAT_TYPE_P (type))
        {
          REAL_VALUE_TYPE max;
          if (HONOR_INFINITIES (type))
            real_inf (&max);
          else
            real_maxval (&max, 0, TYPE_MODE (type));
          return build_real (type, max);
        }
      else if (POINTER_TYPE_P (type))
        {
          wide_int max
            = wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type));
          return wide_int_to_tree (type, max);
        }
      else
        {
          gcc_assert (INTEGRAL_TYPE_P (type));
          return TYPE_MAX_VALUE (type);
        }

    default:
      gcc_unreachable ();
    }
}

/* Return alignment to be assumed for var in CLAUSE, which should be
   OMP_CLAUSE_ALIGNED.  */

static tree
omp_clause_aligned_alignment (tree clause)
{
  if (OMP_CLAUSE_ALIGNED_ALIGNMENT (clause))
    return OMP_CLAUSE_ALIGNED_ALIGNMENT (clause);

  /* Otherwise return implementation defined alignment.  */
  unsigned int al = 1;
  machine_mode mode, vmode;
  int vs = targetm.vectorize.autovectorize_vector_sizes ();
  if (vs)
    vs = 1 << floor_log2 (vs);
  static enum mode_class classes[]
    = { MODE_INT, MODE_VECTOR_INT, MODE_FLOAT, MODE_VECTOR_FLOAT };
  for (int i = 0; i < 4; i += 2)
    for (mode = GET_CLASS_NARROWEST_MODE (classes[i]);
         mode != VOIDmode;
         mode = GET_MODE_WIDER_MODE (mode))
      {
        vmode = targetm.vectorize.preferred_simd_mode (mode);
        if (GET_MODE_CLASS (vmode) != classes[i + 1])
          continue;
        while (vs
               && GET_MODE_SIZE (vmode) < vs
               && GET_MODE_2XWIDER_MODE (vmode) != VOIDmode)
          vmode = GET_MODE_2XWIDER_MODE (vmode);
        
        tree type = lang_hooks.types.type_for_mode (mode, 1);
        if (type == NULL_TREE || TYPE_MODE (type) != mode)
          continue;
        type = build_vector_type (type, GET_MODE_SIZE (vmode)
                                        / GET_MODE_SIZE (mode));
        if (TYPE_MODE (type) != vmode)
          continue;
        if (TYPE_ALIGN_UNIT (type) > al)
          al = TYPE_ALIGN_UNIT (type);
      }
  return build_int_cst (integer_type_node, al);
}

/* Return maximum possible vectorization factor for the target.  */

static int
omp_max_vf (void)
{
  if (!optimize
      || optimize_debug
      || !flag_tree_loop_optimize
      || (!flag_tree_loop_vectorize
          && (global_options_set.x_flag_tree_loop_vectorize
              || global_options_set.x_flag_tree_vectorize)))
    return 1;

  int vs = targetm.vectorize.autovectorize_vector_sizes ();
  if (vs)
    {
      vs = 1 << floor_log2 (vs);
      return vs;
    }
  machine_mode vqimode = targetm.vectorize.preferred_simd_mode (QImode);
  if (GET_MODE_CLASS (vqimode) == MODE_VECTOR_INT)
    return GET_MODE_NUNITS (vqimode);
  return 1;
}

/* Helper function of lower_rec_input_clauses, used for #pragma omp simd
   privatization.  */

static bool
lower_rec_simd_input_clauses (tree new_var, omp_context *ctx, int &max_vf,
                              tree &idx, tree &lane, tree &ivar, tree &lvar)
{
  if (max_vf == 0)
    {
      max_vf = omp_max_vf ();
      if (max_vf > 1)
        {
          tree c = find_omp_clause (gimple_omp_for_clauses (ctx->stmt),
                                    OMP_CLAUSE_SAFELEN);
          if (c && TREE_CODE (OMP_CLAUSE_SAFELEN_EXPR (c)) != INTEGER_CST)
            max_vf = 1;
          else if (c && compare_tree_int (OMP_CLAUSE_SAFELEN_EXPR (c),
                                          max_vf) == -1)
            max_vf = tree_to_shwi (OMP_CLAUSE_SAFELEN_EXPR (c));
        }
      if (max_vf > 1)
        {
          idx = create_tmp_var (unsigned_type_node);
          lane = create_tmp_var (unsigned_type_node);
        }
    }
  if (max_vf == 1)
    return false;

  tree atype = build_array_type_nelts (TREE_TYPE (new_var), max_vf);
  tree avar = create_tmp_var_raw (atype);
  if (TREE_ADDRESSABLE (new_var))
    TREE_ADDRESSABLE (avar) = 1;
  DECL_ATTRIBUTES (avar)
    = tree_cons (get_identifier ("omp simd array"), NULL,
                 DECL_ATTRIBUTES (avar));
  gimple_add_tmp_var (avar);
  ivar = build4 (ARRAY_REF, TREE_TYPE (new_var), avar, idx,
                 NULL_TREE, NULL_TREE);
  lvar = build4 (ARRAY_REF, TREE_TYPE (new_var), avar, lane,
                 NULL_TREE, NULL_TREE);
  if (DECL_P (new_var))
    {
      SET_DECL_VALUE_EXPR (new_var, lvar);
      DECL_HAS_VALUE_EXPR_P (new_var) = 1;
    }
  return true;
}

/* Helper function of lower_rec_input_clauses.  For a reference
   in simd reduction, add an underlying variable it will reference.  */

static void
handle_simd_reference (location_t loc, tree new_vard, gimple_seq *ilist)
{
  tree z = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (new_vard)));
  if (TREE_CONSTANT (z))
    {
      const char *name = NULL;
      if (DECL_NAME (new_vard))
        name = IDENTIFIER_POINTER (DECL_NAME (new_vard));

      z = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (new_vard)), name);
      gimple_add_tmp_var (z);
      TREE_ADDRESSABLE (z) = 1;
      z = build_fold_addr_expr_loc (loc, z);
      gimplify_assign (new_vard, z, ilist);
    }
}

/* Generate code to implement the input clauses, FIRSTPRIVATE and COPYIN,
   from the receiver (aka child) side and initializers for REFERENCE_TYPE
   private variables.  Initialization statements go in ILIST, while calls
   to destructors go in DLIST.  */

static void
lower_rec_input_clauses (tree clauses, gimple_seq *ilist, gimple_seq *dlist,
                         omp_context *ctx, struct omp_for_data *fd)
{
  tree c, dtor, copyin_seq, x, ptr;
  bool copyin_by_ref = false;
  bool lastprivate_firstprivate = false;
  bool reduction_omp_orig_ref = false;
  int pass;
  bool is_simd = (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR
                  && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD);
  int max_vf = 0;
  tree lane = NULL_TREE, idx = NULL_TREE;
  tree ivar = NULL_TREE, lvar = NULL_TREE;
  gimple_seq llist[2] = { NULL, NULL };

  copyin_seq = NULL;

  /* Set max_vf=1 (which will later enforce safelen=1) in simd loops
     with data sharing clauses referencing variable sized vars.  That
     is unnecessarily hard to support and very unlikely to result in
     vectorized code anyway.  */
  if (is_simd)
    for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
      switch (OMP_CLAUSE_CODE (c))
        {
        case OMP_CLAUSE_LINEAR:
          if (OMP_CLAUSE_LINEAR_ARRAY (c))
            max_vf = 1;
          /* FALLTHRU */
        case OMP_CLAUSE_REDUCTION:
        case OMP_CLAUSE_PRIVATE:
        case OMP_CLAUSE_FIRSTPRIVATE:
        case OMP_CLAUSE_LASTPRIVATE:
          if (is_variable_sized (OMP_CLAUSE_DECL (c)))
            max_vf = 1;
          break;
        default:
          continue;
        }

  /* Do all the fixed sized types in the first pass, and the variable sized
     types in the second pass.  This makes sure that the scalar arguments to
     the variable sized types are processed before we use them in the
     variable sized operations.  */
  for (pass = 0; pass < 2; ++pass)
    {
      for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
        {
          enum omp_clause_code c_kind = OMP_CLAUSE_CODE (c);
          tree var, new_var;
          bool by_ref;
          location_t clause_loc = OMP_CLAUSE_LOCATION (c);

          switch (c_kind)
            {
            case OMP_CLAUSE_PRIVATE:
              if (OMP_CLAUSE_PRIVATE_DEBUG (c))
                continue;
              break;
            case OMP_CLAUSE_SHARED:
              /* Ignore shared directives in teams construct.  */
              if (gimple_code (ctx->stmt) == GIMPLE_OMP_TEAMS)
                continue;
              if (maybe_lookup_decl (OMP_CLAUSE_DECL (c), ctx) == NULL)
                {
                  gcc_assert (is_global_var (OMP_CLAUSE_DECL (c)));
                  continue;
                }
            case OMP_CLAUSE_FIRSTPRIVATE:
            case OMP_CLAUSE_COPYIN:
            case OMP_CLAUSE_LINEAR:
              break;
            case OMP_CLAUSE_REDUCTION:
              if (OMP_CLAUSE_REDUCTION_OMP_ORIG_REF (c))
                reduction_omp_orig_ref = true;
              break;
            case OMP_CLAUSE__LOOPTEMP_:
              /* Handle _looptemp_ clauses only on parallel.  */
              if (fd)
                continue;
              break;
            case OMP_CLAUSE_LASTPRIVATE:
              if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
                {
                  lastprivate_firstprivate = true;
                  if (pass != 0)
                    continue;
                }
              /* Even without corresponding firstprivate, if
                 decl is Fortran allocatable, it needs outer var
                 reference.  */
              else if (pass == 0
                       && lang_hooks.decls.omp_private_outer_ref
                                                        (OMP_CLAUSE_DECL (c)))
                lastprivate_firstprivate = true;
              break;
            case OMP_CLAUSE_ALIGNED:
              if (pass == 0)
                continue;
              var = OMP_CLAUSE_DECL (c);
              if (TREE_CODE (TREE_TYPE (var)) == POINTER_TYPE
                  && !is_global_var (var))
                {
                  new_var = maybe_lookup_decl (var, ctx);
                  if (new_var == NULL_TREE)
                    new_var = maybe_lookup_decl_in_outer_ctx (var, ctx);
                  x = builtin_decl_explicit (BUILT_IN_ASSUME_ALIGNED);
                  x = build_call_expr_loc (clause_loc, x, 2, new_var,
                                           omp_clause_aligned_alignment (c));
                  x = fold_convert_loc (clause_loc, TREE_TYPE (new_var), x);
                  x = build2 (MODIFY_EXPR, TREE_TYPE (new_var), new_var, x);
                  gimplify_and_add (x, ilist);
                }
              else if (TREE_CODE (TREE_TYPE (var)) == ARRAY_TYPE
                       && is_global_var (var))
                {
                  tree ptype = build_pointer_type (TREE_TYPE (var)), t, t2;
                  new_var = lookup_decl (var, ctx);
                  t = maybe_lookup_decl_in_outer_ctx (var, ctx);
                  t = build_fold_addr_expr_loc (clause_loc, t);
                  t2 = builtin_decl_explicit (BUILT_IN_ASSUME_ALIGNED);
                  t = build_call_expr_loc (clause_loc, t2, 2, t,
                                           omp_clause_aligned_alignment (c));
                  t = fold_convert_loc (clause_loc, ptype, t);
                  x = create_tmp_var (ptype);
                  t = build2 (MODIFY_EXPR, ptype, x, t);
                  gimplify_and_add (t, ilist);
                  t = build_simple_mem_ref_loc (clause_loc, x);
                  SET_DECL_VALUE_EXPR (new_var, t);
                  DECL_HAS_VALUE_EXPR_P (new_var) = 1;
                }
              continue;
            default:
              continue;
            }

          new_var = var = OMP_CLAUSE_DECL (c);
          if (c_kind != OMP_CLAUSE_COPYIN)
            new_var = lookup_decl (var, ctx);

          if (c_kind == OMP_CLAUSE_SHARED || c_kind == OMP_CLAUSE_COPYIN)
            {
              if (pass != 0)
                continue;
            }
          else if (is_variable_sized (var))
            {
              /* For variable sized types, we need to allocate the
                 actual storage here.  Call alloca and store the
                 result in the pointer decl that we created elsewhere.  */
              if (pass == 0)
                continue;

              if (c_kind != OMP_CLAUSE_FIRSTPRIVATE || !is_task_ctx (ctx))
                {
                  gcall *stmt;
                  tree tmp, atmp;

                  ptr = DECL_VALUE_EXPR (new_var);
                  gcc_assert (TREE_CODE (ptr) == INDIRECT_REF);
                  ptr = TREE_OPERAND (ptr, 0);
                  gcc_assert (DECL_P (ptr));
                  x = TYPE_SIZE_UNIT (TREE_TYPE (new_var));

                  /* void *tmp = __builtin_alloca */
                  atmp = builtin_decl_explicit (BUILT_IN_ALLOCA);
                  stmt = gimple_build_call (atmp, 1, x);
                  tmp = create_tmp_var_raw (ptr_type_node);
                  gimple_add_tmp_var (tmp);
                  gimple_call_set_lhs (stmt, tmp);

                  gimple_seq_add_stmt (ilist, stmt);

                  x = fold_convert_loc (clause_loc, TREE_TYPE (ptr), tmp);
                  gimplify_assign (ptr, x, ilist);
                }
            }
          else if (is_reference (var))
            {
              /* For references that are being privatized for Fortran,
                 allocate new backing storage for the new pointer
                 variable.  This allows us to avoid changing all the
                 code that expects a pointer to something that expects
                 a direct variable.  */
              if (pass == 0)
                continue;

              x = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (new_var)));
              if (c_kind == OMP_CLAUSE_FIRSTPRIVATE && is_task_ctx (ctx))
                {
                  x = build_receiver_ref (var, false, ctx);
                  x = build_fold_addr_expr_loc (clause_loc, x);
                }
              else if (TREE_CONSTANT (x))
                {
                  /* For reduction in SIMD loop, defer adding the
                     initialization of the reference, because if we decide
                     to use SIMD array for it, the initilization could cause
                     expansion ICE.  */
                  if (c_kind == OMP_CLAUSE_REDUCTION && is_simd)
                    x = NULL_TREE;
                  else
                    {
                      const char *name = NULL;
                      if (DECL_NAME (var))
                        name = IDENTIFIER_POINTER (DECL_NAME (new_var));

                      x = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (new_var)),
                                              name);
                      gimple_add_tmp_var (x);
                      TREE_ADDRESSABLE (x) = 1;
                      x = build_fold_addr_expr_loc (clause_loc, x);
                    }
                }
              else
                {
                  tree atmp = builtin_decl_explicit (BUILT_IN_ALLOCA);
                  x = build_call_expr_loc (clause_loc, atmp, 1, x);
                }

              if (x)
                {
                  x = fold_convert_loc (clause_loc, TREE_TYPE (new_var), x);
                  gimplify_assign (new_var, x, ilist);
                }

              new_var = build_simple_mem_ref_loc (clause_loc, new_var);
            }
          else if (c_kind == OMP_CLAUSE_REDUCTION
                   && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
            {
              if (pass == 0)
                continue;
            }
          else if (pass != 0)
            continue;

          switch (OMP_CLAUSE_CODE (c))
            {
            case OMP_CLAUSE_SHARED:
              /* Ignore shared directives in teams construct.  */
              if (gimple_code (ctx->stmt) == GIMPLE_OMP_TEAMS)
                continue;
              /* Shared global vars are just accessed directly.  */
              if (is_global_var (new_var))
                break;
              /* Set up the DECL_VALUE_EXPR for shared variables now.  This
                 needs to be delayed until after fixup_child_record_type so
                 that we get the correct type during the dereference.  */
              by_ref = use_pointer_for_field (var, ctx);
              x = build_receiver_ref (var, by_ref, ctx);
              SET_DECL_VALUE_EXPR (new_var, x);
              DECL_HAS_VALUE_EXPR_P (new_var) = 1;

              /* ??? If VAR is not passed by reference, and the variable
                 hasn't been initialized yet, then we'll get a warning for
                 the store into the omp_data_s structure.  Ideally, we'd be
                 able to notice this and not store anything at all, but
                 we're generating code too early.  Suppress the warning.  */
              if (!by_ref)
                TREE_NO_WARNING (var) = 1;
              break;

            case OMP_CLAUSE_LASTPRIVATE:
              if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
                break;
              /* FALLTHRU */

            case OMP_CLAUSE_PRIVATE:
              if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_PRIVATE)
                x = build_outer_var_ref (var, ctx);
              else if (OMP_CLAUSE_PRIVATE_OUTER_REF (c))
                {
                  if (is_task_ctx (ctx))
                    x = build_receiver_ref (var, false, ctx);
                  else
                    x = build_outer_var_ref (var, ctx);
                }
              else
                x = NULL;
            do_private:
              tree nx;
              nx = lang_hooks.decls.omp_clause_default_ctor (c, new_var, x);
              if (is_simd)
                {
                  tree y = lang_hooks.decls.omp_clause_dtor (c, new_var);
                  if ((TREE_ADDRESSABLE (new_var) || nx || y
                       || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
                      && lower_rec_simd_input_clauses (new_var, ctx, max_vf,
                                                       idx, lane, ivar, lvar))
                    {
                      if (nx)
                        x = lang_hooks.decls.omp_clause_default_ctor
                                                (c, unshare_expr (ivar), x);
                      if (nx && x)
                        gimplify_and_add (x, &llist[0]);
                      if (y)
                        {
                          y = lang_hooks.decls.omp_clause_dtor (c, ivar);
                          if (y)
                            {
                              gimple_seq tseq = NULL;

                              dtor = y;
                              gimplify_stmt (&dtor, &tseq);
                              gimple_seq_add_seq (&llist[1], tseq);
                            }
                        }
                      break;
                    }
                }
              if (nx)
                gimplify_and_add (nx, ilist);
              /* FALLTHRU */

            do_dtor:
              x = lang_hooks.decls.omp_clause_dtor (c, new_var);
              if (x)
                {
                  gimple_seq tseq = NULL;

                  dtor = x;
                  gimplify_stmt (&dtor, &tseq);
                  gimple_seq_add_seq (dlist, tseq);
                }
              break;

            case OMP_CLAUSE_LINEAR:
              if (!OMP_CLAUSE_LINEAR_NO_COPYIN (c))
                goto do_firstprivate;
              if (OMP_CLAUSE_LINEAR_NO_COPYOUT (c))
                x = NULL;
              else
                x = build_outer_var_ref (var, ctx);
              goto do_private;

            case OMP_CLAUSE_FIRSTPRIVATE:
              if (is_task_ctx (ctx))
                {
                  if (is_reference (var) || is_variable_sized (var))
                    goto do_dtor;
                  else if (is_global_var (maybe_lookup_decl_in_outer_ctx (var,
                                                                          ctx))
                           || use_pointer_for_field (var, NULL))
                    {
                      x = build_receiver_ref (var, false, ctx);
                      SET_DECL_VALUE_EXPR (new_var, x);
                      DECL_HAS_VALUE_EXPR_P (new_var) = 1;
                      goto do_dtor;
                    }
                }
            do_firstprivate:
              x = build_outer_var_ref (var, ctx);
              if (is_simd)
                {
                  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR
                      && gimple_omp_for_combined_into_p (ctx->stmt))
                    {
                      tree t = OMP_CLAUSE_LINEAR_STEP (c);
                      tree stept = TREE_TYPE (t);
                      tree ct = find_omp_clause (clauses,
                                                 OMP_CLAUSE__LOOPTEMP_);
                      gcc_assert (ct);
                      tree l = OMP_CLAUSE_DECL (ct);
                      tree n1 = fd->loop.n1;
                      tree step = fd->loop.step;
                      tree itype = TREE_TYPE (l);
                      if (POINTER_TYPE_P (itype))
                        itype = signed_type_for (itype);
                      l = fold_build2 (MINUS_EXPR, itype, l, n1);
                      if (TYPE_UNSIGNED (itype)
                          && fd->loop.cond_code == GT_EXPR)
                        l = fold_build2 (TRUNC_DIV_EXPR, itype,
                                         fold_build1 (NEGATE_EXPR, itype, l),
                                         fold_build1 (NEGATE_EXPR,
                                                      itype, step));
                      else
                        l = fold_build2 (TRUNC_DIV_EXPR, itype, l, step);
                      t = fold_build2 (MULT_EXPR, stept,
                                       fold_convert (stept, l), t);

                      if (OMP_CLAUSE_LINEAR_ARRAY (c))
                        {
                          x = lang_hooks.decls.omp_clause_linear_ctor
                                                        (c, new_var, x, t);
                          gimplify_and_add (x, ilist);
                          goto do_dtor;
                        }

                      if (POINTER_TYPE_P (TREE_TYPE (x)))
                        x = fold_build2 (POINTER_PLUS_EXPR,
                                         TREE_TYPE (x), x, t);
                      else
                        x = fold_build2 (PLUS_EXPR, TREE_TYPE (x), x, t);
                    }

                  if ((OMP_CLAUSE_CODE (c) != OMP_CLAUSE_LINEAR
                       || TREE_ADDRESSABLE (new_var))
                      && lower_rec_simd_input_clauses (new_var, ctx, max_vf,
                                                       idx, lane, ivar, lvar))
                    {
                      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR)
                        {
                          tree iv = create_tmp_var (TREE_TYPE (new_var));
                          x = lang_hooks.decls.omp_clause_copy_ctor (c, iv, x);
                          gimplify_and_add (x, ilist);
                          gimple_stmt_iterator gsi
                            = gsi_start_1 (gimple_omp_body_ptr (ctx->stmt));
                          gassign *g
                            = gimple_build_assign (unshare_expr (lvar), iv);
                          gsi_insert_before_without_update (&gsi, g,
                                                            GSI_SAME_STMT);
                          tree t = OMP_CLAUSE_LINEAR_STEP (c);
                          enum tree_code code = PLUS_EXPR;
                          if (POINTER_TYPE_P (TREE_TYPE (new_var)))
                            code = POINTER_PLUS_EXPR;
                          g = gimple_build_assign (iv, code, iv, t);
                          gsi_insert_before_without_update (&gsi, g,
                                                            GSI_SAME_STMT);
                          break;
                        }
                      x = lang_hooks.decls.omp_clause_copy_ctor
                                                (c, unshare_expr (ivar), x);
                      gimplify_and_add (x, &llist[0]);
                      x = lang_hooks.decls.omp_clause_dtor (c, ivar);
                      if (x)
                        {
                          gimple_seq tseq = NULL;

                          dtor = x;
                          gimplify_stmt (&dtor, &tseq);
                          gimple_seq_add_seq (&llist[1], tseq);
                        }
                      break;
                    }
                }
              x = lang_hooks.decls.omp_clause_copy_ctor (c, new_var, x);
              gimplify_and_add (x, ilist);
              goto do_dtor;

            case OMP_CLAUSE__LOOPTEMP_:
              gcc_assert (is_parallel_ctx (ctx));
              x = build_outer_var_ref (var, ctx);
              x = build2 (MODIFY_EXPR, TREE_TYPE (new_var), new_var, x);
              gimplify_and_add (x, ilist);
              break;

            case OMP_CLAUSE_COPYIN:
              by_ref = use_pointer_for_field (var, NULL);
              x = build_receiver_ref (var, by_ref, ctx);
              x = lang_hooks.decls.omp_clause_assign_op (c, new_var, x);
              append_to_statement_list (x, &copyin_seq);
              copyin_by_ref |= by_ref;
              break;

            case OMP_CLAUSE_REDUCTION:
              if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
                {
                  tree placeholder = OMP_CLAUSE_REDUCTION_PLACEHOLDER (c);
                  gimple tseq;
                  x = build_outer_var_ref (var, ctx);

                  if (is_reference (var)
                      && !useless_type_conversion_p (TREE_TYPE (placeholder),
                                                     TREE_TYPE (x)))
                    x = build_fold_addr_expr_loc (clause_loc, x);
                  SET_DECL_VALUE_EXPR (placeholder, x);
                  DECL_HAS_VALUE_EXPR_P (placeholder) = 1;
                  tree new_vard = new_var;
                  if (is_reference (var))
                    {
                      gcc_assert (TREE_CODE (new_var) == MEM_REF);
                      new_vard = TREE_OPERAND (new_var, 0);
                      gcc_assert (DECL_P (new_vard));
                    }
                  if (is_simd
                      && lower_rec_simd_input_clauses (new_var, ctx, max_vf,
                                                       idx, lane, ivar, lvar))
                    {
                      if (new_vard == new_var)
                        {
                          gcc_assert (DECL_VALUE_EXPR (new_var) == lvar);
                          SET_DECL_VALUE_EXPR (new_var, ivar);
                        }
                      else
                        {
                          SET_DECL_VALUE_EXPR (new_vard,
                                               build_fold_addr_expr (ivar));
                          DECL_HAS_VALUE_EXPR_P (new_vard) = 1;
                        }
                      x = lang_hooks.decls.omp_clause_default_ctor
                                (c, unshare_expr (ivar),
                                 build_outer_var_ref (var, ctx));
                      if (x)
                        gimplify_and_add (x, &llist[0]);
                      if (OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c))
                        {
                          tseq = OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c);
                          lower_omp (&tseq, ctx);
                          gimple_seq_add_seq (&llist[0], tseq);
                        }
                      OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c) = NULL;
                      tseq = OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c);
                      lower_omp (&tseq, ctx);
                      gimple_seq_add_seq (&llist[1], tseq);
                      OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c) = NULL;
                      DECL_HAS_VALUE_EXPR_P (placeholder) = 0;
                      if (new_vard == new_var)
                        SET_DECL_VALUE_EXPR (new_var, lvar);
                      else
                        SET_DECL_VALUE_EXPR (new_vard,
                                             build_fold_addr_expr (lvar));
                      x = lang_hooks.decls.omp_clause_dtor (c, ivar);
                      if (x)
                        {
                          tseq = NULL;
                          dtor = x;
                          gimplify_stmt (&dtor, &tseq);
                          gimple_seq_add_seq (&llist[1], tseq);
                        }
                      break;
                    }
                  /* If this is a reference to constant size reduction var
                     with placeholder, we haven't emitted the initializer
                     for it because it is undesirable if SIMD arrays are used.
                     But if they aren't used, we need to emit the deferred
                     initialization now.  */
                  else if (is_reference (var) && is_simd)
                    handle_simd_reference (clause_loc, new_vard, ilist);
                  x = lang_hooks.decls.omp_clause_default_ctor
                                (c, unshare_expr (new_var),
                                 build_outer_var_ref (var, ctx));
                  if (x)
                    gimplify_and_add (x, ilist);
                  if (OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c))
                    {
                      tseq = OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c);
                      lower_omp (&tseq, ctx);
                      gimple_seq_add_seq (ilist, tseq);
                    }
                  OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c) = NULL;
                  if (is_simd)
                    {
                      tseq = OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c);
                      lower_omp (&tseq, ctx);
                      gimple_seq_add_seq (dlist, tseq);
                      OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c) = NULL;
                    }
                  DECL_HAS_VALUE_EXPR_P (placeholder) = 0;
                  goto do_dtor;
                }
              else
                {
                  x = omp_reduction_init (c, TREE_TYPE (new_var));
                  gcc_assert (TREE_CODE (TREE_TYPE (new_var)) != ARRAY_TYPE);
                  enum tree_code code = OMP_CLAUSE_REDUCTION_CODE (c);

                  /* reduction(-:var) sums up the partial results, so it
                     acts identically to reduction(+:var).  */
                  if (code == MINUS_EXPR)
                    code = PLUS_EXPR;

                  tree new_vard = new_var;
                  if (is_simd && is_reference (var))
                    {
                      gcc_assert (TREE_CODE (new_var) == MEM_REF);
                      new_vard = TREE_OPERAND (new_var, 0);
                      gcc_assert (DECL_P (new_vard));
                    }
                  if (is_simd
                      && lower_rec_simd_input_clauses (new_var, ctx, max_vf,
                                                       idx, lane, ivar, lvar))
                    {
                      tree ref = build_outer_var_ref (var, ctx);

                      gimplify_assign (unshare_expr (ivar), x, &llist[0]);

                      x = build2 (code, TREE_TYPE (ref), ref, ivar);
                      ref = build_outer_var_ref (var, ctx);
                      gimplify_assign (ref, x, &llist[1]);

                      if (new_vard != new_var)
                        {
                          SET_DECL_VALUE_EXPR (new_vard,
                                               build_fold_addr_expr (lvar));
                          DECL_HAS_VALUE_EXPR_P (new_vard) = 1;
                        }
                    }
                  else
                    {
                      if (is_reference (var) && is_simd)
                        handle_simd_reference (clause_loc, new_vard, ilist);
                      gimplify_assign (new_var, x, ilist);
                      if (is_simd)
                        {
                          tree ref = build_outer_var_ref (var, ctx);

                          x = build2 (code, TREE_TYPE (ref), ref, new_var);
                          ref = build_outer_var_ref (var, ctx);
                          gimplify_assign (ref, x, dlist);
                        }
                    }
                }
              break;

            default:
              gcc_unreachable ();
            }
        }
    }

  if (lane)
    {
      tree uid = create_tmp_var (ptr_type_node, "simduid");
      /* Don't want uninit warnings on simduid, it is always uninitialized,
         but we use it not for the value, but for the DECL_UID only.  */
      TREE_NO_WARNING (uid) = 1;
      gimple g
        = gimple_build_call_internal (IFN_GOMP_SIMD_LANE, 1, uid);
      gimple_call_set_lhs (g, lane);
      gimple_stmt_iterator gsi = gsi_start_1 (gimple_omp_body_ptr (ctx->stmt));
      gsi_insert_before_without_update (&gsi, g, GSI_SAME_STMT);
      c = build_omp_clause (UNKNOWN_LOCATION, OMP_CLAUSE__SIMDUID_);
      OMP_CLAUSE__SIMDUID__DECL (c) = uid;
      OMP_CLAUSE_CHAIN (c) = gimple_omp_for_clauses (ctx->stmt);
      gimple_omp_for_set_clauses (ctx->stmt, c);
      g = gimple_build_assign (lane, INTEGER_CST,
                               build_int_cst (unsigned_type_node, 0));
      gimple_seq_add_stmt (ilist, g);
      for (int i = 0; i < 2; i++)
        if (llist[i])
          {
            tree vf = create_tmp_var (unsigned_type_node);
            g = gimple_build_call_internal (IFN_GOMP_SIMD_VF, 1, uid);
            gimple_call_set_lhs (g, vf);
            gimple_seq *seq = i == 0 ? ilist : dlist;
            gimple_seq_add_stmt (seq, g);
            tree t = build_int_cst (unsigned_type_node, 0);
            g = gimple_build_assign (idx, INTEGER_CST, t);
            gimple_seq_add_stmt (seq, g);
            tree body = create_artificial_label (UNKNOWN_LOCATION);
            tree header = create_artificial_label (UNKNOWN_LOCATION);
            tree end = create_artificial_label (UNKNOWN_LOCATION);
            gimple_seq_add_stmt (seq, gimple_build_goto (header));
            gimple_seq_add_stmt (seq, gimple_build_label (body));
            gimple_seq_add_seq (seq, llist[i]);
            t = build_int_cst (unsigned_type_node, 1);
            g = gimple_build_assign (idx, PLUS_EXPR, idx, t);
            gimple_seq_add_stmt (seq, g);
            gimple_seq_add_stmt (seq, gimple_build_label (header));
            g = gimple_build_cond (LT_EXPR, idx, vf, body, end);
            gimple_seq_add_stmt (seq, g);
            gimple_seq_add_stmt (seq, gimple_build_label (end));
          }
    }

  /* The copyin sequence is not to be executed by the main thread, since
     that would result in self-copies.  Perhaps not visible to scalars,
     but it certainly is to C++ operator=.  */
  if (copyin_seq)
    {
      x = build_call_expr (builtin_decl_explicit (BUILT_IN_OMP_GET_THREAD_NUM),
                           0);
      x = build2 (NE_EXPR, boolean_type_node, x,
                  build_int_cst (TREE_TYPE (x), 0));
      x = build3 (COND_EXPR, void_type_node, x, copyin_seq, NULL);
      gimplify_and_add (x, ilist);
    }

  /* If any copyin variable is passed by reference, we must ensure the
     master thread doesn't modify it before it is copied over in all
     threads.  Similarly for variables in both firstprivate and
     lastprivate clauses we need to ensure the lastprivate copying
     happens after firstprivate copying in all threads.  And similarly
     for UDRs if initializer expression refers to omp_orig.  */
  if (copyin_by_ref || lastprivate_firstprivate || reduction_omp_orig_ref)
    {
      /* Don't add any barrier for #pragma omp simd or
         #pragma omp distribute.  */
      if (gimple_code (ctx->stmt) != GIMPLE_OMP_FOR
          || gimple_omp_for_kind (ctx->stmt) == GF_OMP_FOR_KIND_FOR)
        gimple_seq_add_stmt (ilist, build_omp_barrier (NULL_TREE));
    }

  /* If max_vf is non-zero, then we can use only a vectorization factor
     up to the max_vf we chose.  So stick it into the safelen clause.  */
  if (max_vf)
    {
      tree c = find_omp_clause (gimple_omp_for_clauses (ctx->stmt),
                                OMP_CLAUSE_SAFELEN);
      if (c == NULL_TREE
          || (TREE_CODE (OMP_CLAUSE_SAFELEN_EXPR (c)) == INTEGER_CST
              && compare_tree_int (OMP_CLAUSE_SAFELEN_EXPR (c),
                                   max_vf) == 1))
        {
          c = build_omp_clause (UNKNOWN_LOCATION, OMP_CLAUSE_SAFELEN);
          OMP_CLAUSE_SAFELEN_EXPR (c) = build_int_cst (integer_type_node,
                                                       max_vf);
          OMP_CLAUSE_CHAIN (c) = gimple_omp_for_clauses (ctx->stmt);
          gimple_omp_for_set_clauses (ctx->stmt, c);
        }
    }
}


/* Generate code to implement the LASTPRIVATE clauses.  This is used for
   both parallel and workshare constructs.  PREDICATE may be NULL if it's
   always true.   */

static void
lower_lastprivate_clauses (tree clauses, tree predicate, gimple_seq *stmt_list,
                           omp_context *ctx)
{
  tree x, c, label = NULL, orig_clauses = clauses;
  bool par_clauses = false;
  tree simduid = NULL, lastlane = NULL;

  /* Early exit if there are no lastprivate or linear clauses.  */
  for (; clauses ; clauses = OMP_CLAUSE_CHAIN (clauses))
    if (OMP_CLAUSE_CODE (clauses) == OMP_CLAUSE_LASTPRIVATE
        || (OMP_CLAUSE_CODE (clauses) == OMP_CLAUSE_LINEAR
            && !OMP_CLAUSE_LINEAR_NO_COPYOUT (clauses)))
      break;
  if (clauses == NULL)
    {
      /* If this was a workshare clause, see if it had been combined
         with its parallel.  In that case, look for the clauses on the
         parallel statement itself.  */
      if (is_parallel_ctx (ctx))
        return;

      ctx = ctx->outer;
      if (ctx == NULL || !is_parallel_ctx (ctx))
        return;

      clauses = find_omp_clause (gimple_omp_parallel_clauses (ctx->stmt),
                                 OMP_CLAUSE_LASTPRIVATE);
      if (clauses == NULL)
        return;
      par_clauses = true;
    }

  if (predicate)
    {
      gcond *stmt;
      tree label_true, arm1, arm2;

      label = create_artificial_label (UNKNOWN_LOCATION);
      label_true = create_artificial_label (UNKNOWN_LOCATION);
      arm1 = TREE_OPERAND (predicate, 0);
      arm2 = TREE_OPERAND (predicate, 1);
      gimplify_expr (&arm1, stmt_list, NULL, is_gimple_val, fb_rvalue);
      gimplify_expr (&arm2, stmt_list, NULL, is_gimple_val, fb_rvalue);
      stmt = gimple_build_cond (TREE_CODE (predicate), arm1, arm2,
                                label_true, label);
      gimple_seq_add_stmt (stmt_list, stmt);
      gimple_seq_add_stmt (stmt_list, gimple_build_label (label_true));
    }

  if (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR
      && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD)
    {
      simduid = find_omp_clause (orig_clauses, OMP_CLAUSE__SIMDUID_);
      if (simduid)
        simduid = OMP_CLAUSE__SIMDUID__DECL (simduid);
    }

  for (c = clauses; c ;)
    {
      tree var, new_var;
      location_t clause_loc = OMP_CLAUSE_LOCATION (c);

      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE
          || (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR
              && !OMP_CLAUSE_LINEAR_NO_COPYOUT (c)))
        {
          var = OMP_CLAUSE_DECL (c);
          new_var = lookup_decl (var, ctx);

          if (simduid && DECL_HAS_VALUE_EXPR_P (new_var))
            {
              tree val = DECL_VALUE_EXPR (new_var);
              if (TREE_CODE (val) == ARRAY_REF
                  && VAR_P (TREE_OPERAND (val, 0))
                  && lookup_attribute ("omp simd array",
                                       DECL_ATTRIBUTES (TREE_OPERAND (val,
                                                                      0))))
                {
                  if (lastlane == NULL)
                    {
                      lastlane = create_tmp_var (unsigned_type_node);
                      gcall *g
                        = gimple_build_call_internal (IFN_GOMP_SIMD_LAST_LANE,
                                                      2, simduid,
                                                      TREE_OPERAND (val, 1));
                      gimple_call_set_lhs (g, lastlane);
                      gimple_seq_add_stmt (stmt_list, g);
                    }
                  new_var = build4 (ARRAY_REF, TREE_TYPE (val),
                                    TREE_OPERAND (val, 0), lastlane,
                                    NULL_TREE, NULL_TREE);
                }
            }

          if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE
              && OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c))
            {
              lower_omp (&OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c), ctx);
              gimple_seq_add_seq (stmt_list,
                                  OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c));
              OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c) = NULL;
            }
          else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR
                   && OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c))
            {
              lower_omp (&OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c), ctx);
              gimple_seq_add_seq (stmt_list,
                                  OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c));
              OMP_CLAUSE_LINEAR_GIMPLE_SEQ (c) = NULL;
            }

          x = build_outer_var_ref (var, ctx);
          if (is_reference (var))
            new_var = build_simple_mem_ref_loc (clause_loc, new_var);
          x = lang_hooks.decls.omp_clause_assign_op (c, x, new_var);
          gimplify_and_add (x, stmt_list);
        }
      c = OMP_CLAUSE_CHAIN (c);
      if (c == NULL && !par_clauses)
        {
          /* If this was a workshare clause, see if it had been combined
             with its parallel.  In that case, continue looking for the
             clauses also on the parallel statement itself.  */
          if (is_parallel_ctx (ctx))
            break;

          ctx = ctx->outer;
          if (ctx == NULL || !is_parallel_ctx (ctx))
            break;

          c = find_omp_clause (gimple_omp_parallel_clauses (ctx->stmt),
                               OMP_CLAUSE_LASTPRIVATE);
          par_clauses = true;
        }
    }

  if (label)
    gimple_seq_add_stmt (stmt_list, gimple_build_label (label));
}

static void
oacc_lower_reduction_var_helper (gimple_seq *stmt_seqp, omp_context *ctx,
                                 tree tid, tree var, tree new_var)
{
  /* The atomic add at the end of the sum creates unnecessary
     write contention on accelerators.  To work around this,
     create an array to store the partial reductions. Later, in
     lower_omp_for (for openacc), the values of array will be
     combined.  */

  tree t = NULL_TREE, array, x;
  tree type = get_base_type (var);
  gimple stmt;

  /* Now insert the partial reductions into the array.  */

  /* Find the reduction array.  */

  tree ptype = build_pointer_type (type);

  t = lookup_oacc_reduction (oacc_get_reduction_array_id (var), ctx);
  t = build_receiver_ref (t, false, ctx->outer);

  array = create_tmp_var (ptype);
  gimplify_assign (array, t, stmt_seqp);

  tree ptr = create_tmp_var (TREE_TYPE (array));

  /* Find the reduction array.  */

  /* testing a unary conversion.  */
  tree offset = create_tmp_var (sizetype);
  gimplify_assign (offset, TYPE_SIZE_UNIT (type),
                   stmt_seqp);
  t = create_tmp_var (sizetype);
  gimplify_assign (t, unshare_expr (fold_build1 (NOP_EXPR, sizetype, tid)),
                   stmt_seqp);
  stmt = gimple_build_assign (offset, MULT_EXPR, offset, t);
  gimple_seq_add_stmt (stmt_seqp, stmt);

  /* Offset expression.  Does the POINTER_PLUS_EXPR take care
     of adding sizeof(var) to the array?  */
  ptr = create_tmp_var (ptype);
  stmt = gimple_build_assign (unshare_expr (ptr), POINTER_PLUS_EXPR, array,
                              offset);
  gimple_seq_add_stmt (stmt_seqp, stmt);

  /* Move the local sum to gfc$sum[i].  */
  x = unshare_expr (build_simple_mem_ref (ptr));
  stmt = gimplify_assign (x, new_var, stmt_seqp);
}

/* Generate code to implement the REDUCTION clauses.  */

static void
lower_reduction_clauses (tree clauses, gimple_seq *stmt_seqp, omp_context *ctx)
{
  gimple_seq sub_seq = NULL;
  gimple stmt;
  tree x, c, tid = NULL_TREE;
  int count = 0;

  /* SIMD reductions are handled in lower_rec_input_clauses.  */
  if (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR
      && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD)
    return;

  /* First see if there is exactly one reduction clause.  Use OMP_ATOMIC
     update in that case, otherwise use a lock.  */
  for (c = clauses; c && count < 2; c = OMP_CLAUSE_CHAIN (c))
    if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION)
      {
        if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
          {
            /* Never use OMP_ATOMIC for array reductions or UDRs.  */
            count = -1;
            break;
          }
        count++;
      }

  if (count == 0)
    return;

  /* Initialize thread info for OpenACC.  */
  if (is_gimple_omp_oacc (ctx->stmt))
    {
      /* Get the current thread id.  */
      tree call = builtin_decl_explicit (BUILT_IN_GOACC_GET_THREAD_NUM);
      tid = create_tmp_var (TREE_TYPE (TREE_TYPE (call)));
      gimple stmt = gimple_build_call (call, 0);
      gimple_call_set_lhs (stmt, tid);
      gimple_seq_add_stmt (stmt_seqp, stmt);
    }

  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
    {
      tree var, ref, new_var;
      enum tree_code code;
      location_t clause_loc = OMP_CLAUSE_LOCATION (c);

      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_REDUCTION)
        continue;

      var = OMP_CLAUSE_DECL (c);
      new_var = lookup_decl (var, ctx);
      if (is_reference (var))
        new_var = build_simple_mem_ref_loc (clause_loc, new_var);
      ref = build_outer_var_ref (var, ctx);
      code = OMP_CLAUSE_REDUCTION_CODE (c);

      /* reduction(-:var) sums up the partial results, so it acts
         identically to reduction(+:var).  */
      if (code == MINUS_EXPR)
        code = PLUS_EXPR;

      if (is_gimple_omp_oacc (ctx->stmt))
        {
          gcc_checking_assert (!OMP_CLAUSE_REDUCTION_PLACEHOLDER (c));

          oacc_lower_reduction_var_helper (stmt_seqp, ctx, tid, var, new_var);
        }
      else if (count == 1)
        {
          tree addr = build_fold_addr_expr_loc (clause_loc, ref);

          addr = save_expr (addr);
          ref = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (addr)), addr);
          x = fold_build2_loc (clause_loc, code, TREE_TYPE (ref), ref, new_var);
          x = build2 (OMP_ATOMIC, void_type_node, addr, x);
          gimplify_and_add (x, stmt_seqp);
          return;
        }
      else if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
        {
          tree placeholder = OMP_CLAUSE_REDUCTION_PLACEHOLDER (c);

          if (is_reference (var)
              && !useless_type_conversion_p (TREE_TYPE (placeholder),
                                             TREE_TYPE (ref)))
            ref = build_fold_addr_expr_loc (clause_loc, ref);
          SET_DECL_VALUE_EXPR (placeholder, ref);
          DECL_HAS_VALUE_EXPR_P (placeholder) = 1;
          lower_omp (&OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c), ctx);
          gimple_seq_add_seq (&sub_seq, OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c));
          OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c) = NULL;
          OMP_CLAUSE_REDUCTION_PLACEHOLDER (c) = NULL;
        }
      else
        {
          x = build2 (code, TREE_TYPE (ref), ref, new_var);
          ref = build_outer_var_ref (var, ctx);
          gimplify_assign (ref, x, &sub_seq);
        }
    }

  if (is_gimple_omp_oacc (ctx->stmt))
    return;

  stmt = gimple_build_call (builtin_decl_explicit (BUILT_IN_GOMP_ATOMIC_START),
                            0);
  gimple_seq_add_stmt (stmt_seqp, stmt);

  gimple_seq_add_seq (stmt_seqp, sub_seq);

  stmt = gimple_build_call (builtin_decl_explicit (BUILT_IN_GOMP_ATOMIC_END),
                            0);
  gimple_seq_add_stmt (stmt_seqp, stmt);
}


/* Generate code to implement the COPYPRIVATE clauses.  */

static void
lower_copyprivate_clauses (tree clauses, gimple_seq *slist, gimple_seq *rlist,
                            omp_context *ctx)
{
  tree c;

  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
    {
      tree var, new_var, ref, x;
      bool by_ref;
      location_t clause_loc = OMP_CLAUSE_LOCATION (c);

      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_COPYPRIVATE)
        continue;

      var = OMP_CLAUSE_DECL (c);
      by_ref = use_pointer_for_field (var, NULL);

      ref = build_sender_ref (var, ctx);
      x = new_var = lookup_decl_in_outer_ctx (var, ctx);
      if (by_ref)
        {
          x = build_fold_addr_expr_loc (clause_loc, new_var);
          x = fold_convert_loc (clause_loc, TREE_TYPE (ref), x);
        }
      gimplify_assign (ref, x, slist);

      ref = build_receiver_ref (var, false, ctx);
      if (by_ref)
        {
          ref = fold_convert_loc (clause_loc,
                                  build_pointer_type (TREE_TYPE (new_var)),
                                  ref);
          ref = build_fold_indirect_ref_loc (clause_loc, ref);
        }
      if (is_reference (var))
        {
          ref = fold_convert_loc (clause_loc, TREE_TYPE (new_var), ref);
          ref = build_simple_mem_ref_loc (clause_loc, ref);
          new_var = build_simple_mem_ref_loc (clause_loc, new_var);
        }
      x = lang_hooks.decls.omp_clause_assign_op (c, new_var, ref);
      gimplify_and_add (x, rlist);
    }
}


/* Generate code to implement the clauses, FIRSTPRIVATE, COPYIN, LASTPRIVATE,
   and REDUCTION from the sender (aka parent) side.  */

static void
lower_send_clauses (tree clauses, gimple_seq *ilist, gimple_seq *olist,
                    omp_context *ctx)
{
  tree c;

  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
    {
      tree val, ref, x, var;
      bool by_ref, do_in = false, do_out = false;
      location_t clause_loc = OMP_CLAUSE_LOCATION (c);

      switch (OMP_CLAUSE_CODE (c))
        {
        case OMP_CLAUSE_PRIVATE:
          if (OMP_CLAUSE_PRIVATE_OUTER_REF (c))
            break;
          continue;
        case OMP_CLAUSE_FIRSTPRIVATE:
        case OMP_CLAUSE_COPYIN:
        case OMP_CLAUSE_LASTPRIVATE:
        case OMP_CLAUSE_REDUCTION:
        case OMP_CLAUSE__LOOPTEMP_:
          break;
        default:
          continue;
        }

      val = OMP_CLAUSE_DECL (c);
      var = lookup_decl_in_outer_ctx (val, ctx);

      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_COPYIN
          && is_global_var (var))
        continue;
      if (is_variable_sized (val))
        continue;
      by_ref = use_pointer_for_field (val, NULL);

      switch (OMP_CLAUSE_CODE (c))
        {
        case OMP_CLAUSE_PRIVATE:
        case OMP_CLAUSE_FIRSTPRIVATE:
        case OMP_CLAUSE_COPYIN:
        case OMP_CLAUSE__LOOPTEMP_:
          do_in = true;
          break;

        case OMP_CLAUSE_LASTPRIVATE:
          if (by_ref || is_reference (val))
            {
              if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
                continue;
              do_in = true;
            }
          else
            {
              do_out = true;
              if (lang_hooks.decls.omp_private_outer_ref (val))
                do_in = true;
            }
          break;

        case OMP_CLAUSE_REDUCTION:
          do_in = true;
          do_out = !(by_ref || is_reference (val));
          break;

        default:
          gcc_unreachable ();
        }

      if (do_in)
        {
          ref = build_sender_ref (val, ctx);
          x = by_ref ? build_fold_addr_expr_loc (clause_loc, var) : var;
          gimplify_assign (ref, x, ilist);
          if (is_task_ctx (ctx))
            DECL_ABSTRACT_ORIGIN (TREE_OPERAND (ref, 1)) = NULL;
        }

      if (do_out)
        {
          ref = build_sender_ref (val, ctx);
          gimplify_assign (var, ref, olist);
        }
    }
}

/* Generate code to implement SHARED from the sender (aka parent)
   side.  This is trickier, since GIMPLE_OMP_PARALLEL_CLAUSES doesn't
   list things that got automatically shared.  */

static void
lower_send_shared_vars (gimple_seq *ilist, gimple_seq *olist, omp_context *ctx)
{
  tree var, ovar, nvar, f, x, record_type;

  if (ctx->record_type == NULL)
    return;

  record_type = ctx->srecord_type ? ctx->srecord_type : ctx->record_type;
  for (f = TYPE_FIELDS (record_type); f ; f = DECL_CHAIN (f))
    {
      ovar = DECL_ABSTRACT_ORIGIN (f);
      nvar = maybe_lookup_decl (ovar, ctx);
      if (!nvar || !DECL_HAS_VALUE_EXPR_P (nvar))
        continue;

      /* If CTX is a nested parallel directive.  Find the immediately
         enclosing parallel or workshare construct that contains a
         mapping for OVAR.  */
      var = lookup_decl_in_outer_ctx (ovar, ctx);

      if (use_pointer_for_field (ovar, ctx))
        {
          x = build_sender_ref (ovar, ctx);
          var = build_fold_addr_expr (var);
          gimplify_assign (x, var, ilist);
        }
      else
        {
          x = build_sender_ref (ovar, ctx);
          gimplify_assign (x, var, ilist);

          if (!TREE_READONLY (var)
              /* We don't need to receive a new reference to a result
                 or parm decl.  In fact we may not store to it as we will
                 invalidate any pending RSO and generate wrong gimple
                 during inlining.  */
              && !((TREE_CODE (var) == RESULT_DECL
                    || TREE_CODE (var) == PARM_DECL)
                   && DECL_BY_REFERENCE (var)))
            {
              x = build_sender_ref (ovar, ctx);
              gimplify_assign (var, x, olist);
            }
        }
    }
}


/* A convenience function to build an empty GIMPLE_COND with just the
   condition.  */

static gcond *
gimple_build_cond_empty (tree cond)
{
  enum tree_code pred_code;
  tree lhs, rhs;

  gimple_cond_get_ops_from_tree (cond, &pred_code, &lhs, &rhs);
  return gimple_build_cond (pred_code, lhs, rhs, NULL_TREE, NULL_TREE);
}


/* Build the function calls to GOMP_parallel_start etc to actually
   generate the parallel operation.  REGION is the parallel region
   being expanded.  BB is the block where to insert the code.  WS_ARGS
   will be set if this is a call to a combined parallel+workshare
   construct, it contains the list of additional arguments needed by
   the workshare construct.  */

static void
expand_parallel_call (struct omp_region *region, basic_block bb,
                      gomp_parallel *entry_stmt,
                      vec<tree, va_gc> *ws_args)
{
  tree t, t1, t2, val, cond, c, clauses, flags;
  gimple_stmt_iterator gsi;
  gimple stmt;
  enum built_in_function start_ix;
  int start_ix2;
  location_t clause_loc;
  vec<tree, va_gc> *args;

  clauses = gimple_omp_parallel_clauses (entry_stmt);

  /* Determine what flavor of GOMP_parallel we will be
     emitting.  */
  start_ix = BUILT_IN_GOMP_PARALLEL;
  if (is_combined_parallel (region))
    {
      switch (region->inner->type)
        {
        case GIMPLE_OMP_FOR:
          gcc_assert (region->inner->sched_kind != OMP_CLAUSE_SCHEDULE_AUTO);
          start_ix2 = ((int)BUILT_IN_GOMP_PARALLEL_LOOP_STATIC
                       + (region->inner->sched_kind
                          == OMP_CLAUSE_SCHEDULE_RUNTIME
                          ? 3 : region->inner->sched_kind));
          start_ix = (enum built_in_function)start_ix2;
          break;
        case GIMPLE_OMP_SECTIONS:
          start_ix = BUILT_IN_GOMP_PARALLEL_SECTIONS;
          break;
        default:
          gcc_unreachable ();
        }
    }

  /* By default, the value of NUM_THREADS is zero (selected at run time)
     and there is no conditional.  */
  cond = NULL_TREE;
  val = build_int_cst (unsigned_type_node, 0);
  flags = build_int_cst (unsigned_type_node, 0);

  c = find_omp_clause (clauses, OMP_CLAUSE_IF);
  if (c)
    cond = OMP_CLAUSE_IF_EXPR (c);

  c = find_omp_clause (clauses, OMP_CLAUSE_NUM_THREADS);
  if (c)
    {
      val = OMP_CLAUSE_NUM_THREADS_EXPR (c);
      clause_loc = OMP_CLAUSE_LOCATION (c);
    }
  else
    clause_loc = gimple_location (entry_stmt);

  c = find_omp_clause (clauses, OMP_CLAUSE_PROC_BIND);
  if (c)
    flags = build_int_cst (unsigned_type_node, OMP_CLAUSE_PROC_BIND_KIND (c));

  /* Ensure 'val' is of the correct type.  */
  val = fold_convert_loc (clause_loc, unsigned_type_node, val);

  /* If we found the clause 'if (cond)', build either
     (cond != 0) or (cond ? val : 1u).  */
  if (cond)
    {
      cond = gimple_boolify (cond);

      if (integer_zerop (val))
        val = fold_build2_loc (clause_loc,
                           EQ_EXPR, unsigned_type_node, cond,
                           build_int_cst (TREE_TYPE (cond), 0));
      else
        {
          basic_block cond_bb, then_bb, else_bb;
          edge e, e_then, e_else;
          tree tmp_then, tmp_else, tmp_join, tmp_var;

          tmp_var = create_tmp_var (TREE_TYPE (val));
          if (gimple_in_ssa_p (cfun))
            {
              tmp_then = make_ssa_name (tmp_var);
              tmp_else = make_ssa_name (tmp_var);
              tmp_join = make_ssa_name (tmp_var);
            }
          else
            {
              tmp_then = tmp_var;
              tmp_else = tmp_var;
              tmp_join = tmp_var;
            }

          e = split_block_after_labels (bb);
          cond_bb = e->src;
          bb = e->dest;
          remove_edge (e);

          then_bb = create_empty_bb (cond_bb);
          else_bb = create_empty_bb (then_bb);
          set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb);
          set_immediate_dominator (CDI_DOMINATORS, else_bb, cond_bb);

          stmt = gimple_build_cond_empty (cond);
          gsi = gsi_start_bb (cond_bb);
          gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

          gsi = gsi_start_bb (then_bb);
          stmt = gimple_build_assign (tmp_then, val);
          gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

          gsi = gsi_start_bb (else_bb);
          stmt = gimple_build_assign
                   (tmp_else, build_int_cst (unsigned_type_node, 1));
          gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

          make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE);
          make_edge (cond_bb, else_bb, EDGE_FALSE_VALUE);
          add_bb_to_loop (then_bb, cond_bb->loop_father);
          add_bb_to_loop (else_bb, cond_bb->loop_father);
          e_then = make_edge (then_bb, bb, EDGE_FALLTHRU);
          e_else = make_edge (else_bb, bb, EDGE_FALLTHRU);

          if (gimple_in_ssa_p (cfun))
            {
              gphi *phi = create_phi_node (tmp_join, bb);
              add_phi_arg (phi, tmp_then, e_then, UNKNOWN_LOCATION);
              add_phi_arg (phi, tmp_else, e_else, UNKNOWN_LOCATION);
            }

          val = tmp_join;
        }

      gsi = gsi_start_bb (bb);
      val = force_gimple_operand_gsi (&gsi, val, true, NULL_TREE,
                                      false, GSI_CONTINUE_LINKING);
    }

  gsi = gsi_last_bb (bb);
  t = gimple_omp_parallel_data_arg (entry_stmt);
  if (t == NULL)
    t1 = null_pointer_node;
  else
    t1 = build_fold_addr_expr (t);
  t2 = build_fold_addr_expr (gimple_omp_parallel_child_fn (entry_stmt));

  vec_alloc (args, 4 + vec_safe_length (ws_args));
  args->quick_push (t2);
  args->quick_push (t1);
  args->quick_push (val);
  if (ws_args)
    args->splice (*ws_args);
  args->quick_push (flags);

  t = build_call_expr_loc_vec (UNKNOWN_LOCATION,
                               builtin_decl_explicit (start_ix), args);

  force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                            false, GSI_CONTINUE_LINKING);
}

/* Insert a function call whose name is FUNC_NAME with the information from
   ENTRY_STMT into the basic_block BB.  */

static void
expand_cilk_for_call (basic_block bb, gomp_parallel *entry_stmt,
                      vec <tree, va_gc> *ws_args)
{
  tree t, t1, t2;
  gimple_stmt_iterator gsi;
  vec <tree, va_gc> *args;

  gcc_assert (vec_safe_length (ws_args) == 2);
  tree func_name = (*ws_args)[0];
  tree grain = (*ws_args)[1];

  tree clauses = gimple_omp_parallel_clauses (entry_stmt);
  tree count = find_omp_clause (clauses, OMP_CLAUSE__CILK_FOR_COUNT_);
  gcc_assert (count != NULL_TREE);
  count = OMP_CLAUSE_OPERAND (count, 0);

  gsi = gsi_last_bb (bb);
  t = gimple_omp_parallel_data_arg (entry_stmt);
  if (t == NULL)
    t1 = null_pointer_node;
  else
    t1 = build_fold_addr_expr (t);
  t2 = build_fold_addr_expr (gimple_omp_parallel_child_fn (entry_stmt));

  vec_alloc (args, 4);
  args->quick_push (t2);
  args->quick_push (t1);
  args->quick_push (count);
  args->quick_push (grain);
  t = build_call_expr_loc_vec (UNKNOWN_LOCATION, func_name, args);

  force_gimple_operand_gsi (&gsi, t, true, NULL_TREE, false,
                            GSI_CONTINUE_LINKING);
}

/* Build the function call to GOMP_task to actually
   generate the task operation.  BB is the block where to insert the code.  */

static void
expand_task_call (basic_block bb, gomp_task *entry_stmt)
{
  tree t, t1, t2, t3, flags, cond, c, c2, clauses, depend;
  gimple_stmt_iterator gsi;
  location_t loc = gimple_location (entry_stmt);

  clauses = gimple_omp_task_clauses (entry_stmt);

  c = find_omp_clause (clauses, OMP_CLAUSE_IF);
  if (c)
    cond = gimple_boolify (OMP_CLAUSE_IF_EXPR (c));
  else
    cond = boolean_true_node;

  c = find_omp_clause (clauses, OMP_CLAUSE_UNTIED);
  c2 = find_omp_clause (clauses, OMP_CLAUSE_MERGEABLE);
  depend = find_omp_clause (clauses, OMP_CLAUSE_DEPEND);
  flags = build_int_cst (unsigned_type_node,
                         (c ? 1 : 0) + (c2 ? 4 : 0) + (depend ? 8 : 0));

  c = find_omp_clause (clauses, OMP_CLAUSE_FINAL);
  if (c)
    {
      c = gimple_boolify (OMP_CLAUSE_FINAL_EXPR (c));
      c = fold_build3_loc (loc, COND_EXPR, unsigned_type_node, c,
                           build_int_cst (unsigned_type_node, 2),
                           build_int_cst (unsigned_type_node, 0));
      flags = fold_build2_loc (loc, PLUS_EXPR, unsigned_type_node, flags, c);
    }
  if (depend)
    depend = OMP_CLAUSE_DECL (depend);
  else
    depend = build_int_cst (ptr_type_node, 0);

  gsi = gsi_last_bb (bb);
  t = gimple_omp_task_data_arg (entry_stmt);
  if (t == NULL)
    t2 = null_pointer_node;
  else
    t2 = build_fold_addr_expr_loc (loc, t);
  t1 = build_fold_addr_expr_loc (loc, gimple_omp_task_child_fn (entry_stmt));
  t = gimple_omp_task_copy_fn (entry_stmt);
  if (t == NULL)
    t3 = null_pointer_node;
  else
    t3 = build_fold_addr_expr_loc (loc, t);

  t = build_call_expr (builtin_decl_explicit (BUILT_IN_GOMP_TASK),
                       8, t1, t2, t3,
                       gimple_omp_task_arg_size (entry_stmt),
                       gimple_omp_task_arg_align (entry_stmt), cond, flags,
                       depend);

  force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                            false, GSI_CONTINUE_LINKING);
}


/* If exceptions are enabled, wrap the statements in BODY in a MUST_NOT_THROW
   catch handler and return it.  This prevents programs from violating the
   structured block semantics with throws.  */

static gimple_seq
maybe_catch_exception (gimple_seq body)
{
  gimple g;
  tree decl;

  if (!flag_exceptions)
    return body;

  if (lang_hooks.eh_protect_cleanup_actions != NULL)
    decl = lang_hooks.eh_protect_cleanup_actions ();
  else
    decl = builtin_decl_explicit (BUILT_IN_TRAP);

  g = gimple_build_eh_must_not_throw (decl);
  g = gimple_build_try (body, gimple_seq_alloc_with_stmt (g),
                        GIMPLE_TRY_CATCH);

 return gimple_seq_alloc_with_stmt (g);
}

/* Chain all the DECLs in LIST by their TREE_CHAIN fields.  */

static tree
vec2chain (vec<tree, va_gc> *v)
{
  tree chain = NULL_TREE, t;
  unsigned ix;

  FOR_EACH_VEC_SAFE_ELT_REVERSE (v, ix, t)
    {
      DECL_CHAIN (t) = chain;
      chain = t;
    }

  return chain;
}


/* Remove barriers in REGION->EXIT's block.  Note that this is only
   valid for GIMPLE_OMP_PARALLEL regions.  Since the end of a parallel region
   is an implicit barrier, any workshare inside the GIMPLE_OMP_PARALLEL that
   left a barrier at the end of the GIMPLE_OMP_PARALLEL region can now be
   removed.  */

static void
remove_exit_barrier (struct omp_region *region)
{
  gimple_stmt_iterator gsi;
  basic_block exit_bb;
  edge_iterator ei;
  edge e;
  gimple stmt;
  int any_addressable_vars = -1;

  exit_bb = region->exit;

  /* If the parallel region doesn't return, we don't have REGION->EXIT
     block at all.  */
  if (! exit_bb)
    return;

  /* The last insn in the block will be the parallel's GIMPLE_OMP_RETURN.  The
     workshare's GIMPLE_OMP_RETURN will be in a preceding block.  The kinds of
     statements that can appear in between are extremely limited -- no
     memory operations at all.  Here, we allow nothing at all, so the
     only thing we allow to precede this GIMPLE_OMP_RETURN is a label.  */
  gsi = gsi_last_bb (exit_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_RETURN);
  gsi_prev (&gsi);
  if (!gsi_end_p (gsi) && gimple_code (gsi_stmt (gsi)) != GIMPLE_LABEL)
    return;

  FOR_EACH_EDGE (e, ei, exit_bb->preds)
    {
      gsi = gsi_last_bb (e->src);
      if (gsi_end_p (gsi))
        continue;
      stmt = gsi_stmt (gsi);
      if (gimple_code (stmt) == GIMPLE_OMP_RETURN
          && !gimple_omp_return_nowait_p (stmt))
        {
          /* OpenMP 3.0 tasks unfortunately prevent this optimization
             in many cases.  If there could be tasks queued, the barrier
             might be needed to let the tasks run before some local
             variable of the parallel that the task uses as shared
             runs out of scope.  The task can be spawned either
             from within current function (this would be easy to check)
             or from some function it calls and gets passed an address
             of such a variable.  */
          if (any_addressable_vars < 0)
            {
              gomp_parallel *parallel_stmt
                = as_a <gomp_parallel *> (last_stmt (region->entry));
              tree child_fun = gimple_omp_parallel_child_fn (parallel_stmt);
              tree local_decls, block, decl;
              unsigned ix;

              any_addressable_vars = 0;
              FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (child_fun), ix, decl)
                if (TREE_ADDRESSABLE (decl))
                  {
                    any_addressable_vars = 1;
                    break;
                  }
              for (block = gimple_block (stmt);
                   !any_addressable_vars
                   && block
                   && TREE_CODE (block) == BLOCK;
                   block = BLOCK_SUPERCONTEXT (block))
                {
                  for (local_decls = BLOCK_VARS (block);
                       local_decls;
                       local_decls = DECL_CHAIN (local_decls))
                    if (TREE_ADDRESSABLE (local_decls))
                      {
                        any_addressable_vars = 1;
                        break;
                      }
                  if (block == gimple_block (parallel_stmt))
                    break;
                }
            }
          if (!any_addressable_vars)
            gimple_omp_return_set_nowait (stmt);
        }
    }
}

static void
remove_exit_barriers (struct omp_region *region)
{
  if (region->type == GIMPLE_OMP_PARALLEL)
    remove_exit_barrier (region);

  if (region->inner)
    {
      region = region->inner;
      remove_exit_barriers (region);
      while (region->next)
        {
          region = region->next;
          remove_exit_barriers (region);
        }
    }
}

/* Optimize omp_get_thread_num () and omp_get_num_threads ()
   calls.  These can't be declared as const functions, but
   within one parallel body they are constant, so they can be
   transformed there into __builtin_omp_get_{thread_num,num_threads} ()
   which are declared const.  Similarly for task body, except
   that in untied task omp_get_thread_num () can change at any task
   scheduling point.  */

static void
optimize_omp_library_calls (gimple entry_stmt)
{
  basic_block bb;
  gimple_stmt_iterator gsi;
  tree thr_num_tree = builtin_decl_explicit (BUILT_IN_OMP_GET_THREAD_NUM);
  tree thr_num_id = DECL_ASSEMBLER_NAME (thr_num_tree);
  tree num_thr_tree = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_THREADS);
  tree num_thr_id = DECL_ASSEMBLER_NAME (num_thr_tree);
  bool untied_task = (gimple_code (entry_stmt) == GIMPLE_OMP_TASK
                      && find_omp_clause (gimple_omp_task_clauses (entry_stmt),
                                          OMP_CLAUSE_UNTIED) != NULL);

  FOR_EACH_BB_FN (bb, cfun)
    for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
      {
        gimple call = gsi_stmt (gsi);
        tree decl;

        if (is_gimple_call (call)
            && (decl = gimple_call_fndecl (call))
            && DECL_EXTERNAL (decl)
            && TREE_PUBLIC (decl)
            && DECL_INITIAL (decl) == NULL)
          {
            tree built_in;

            if (DECL_NAME (decl) == thr_num_id)
              {
                /* In #pragma omp task untied omp_get_thread_num () can change
                   during the execution of the task region.  */
                if (untied_task)
                  continue;
                built_in = builtin_decl_explicit (BUILT_IN_OMP_GET_THREAD_NUM);
              }
            else if (DECL_NAME (decl) == num_thr_id)
              built_in = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_THREADS);
            else
              continue;

            if (DECL_ASSEMBLER_NAME (decl) != DECL_ASSEMBLER_NAME (built_in)
                || gimple_call_num_args (call) != 0)
              continue;

            if (flag_exceptions && !TREE_NOTHROW (decl))
              continue;

            if (TREE_CODE (TREE_TYPE (decl)) != FUNCTION_TYPE
                || !types_compatible_p (TREE_TYPE (TREE_TYPE (decl)),
                                        TREE_TYPE (TREE_TYPE (built_in))))
              continue;

            gimple_call_set_fndecl (call, built_in);
          }
      }
}

/* Callback for expand_omp_build_assign.  Return non-NULL if *tp needs to be
   regimplified.  */

static tree
expand_omp_regimplify_p (tree *tp, int *walk_subtrees, void *)
{
  tree t = *tp;

  /* Any variable with DECL_VALUE_EXPR needs to be regimplified.  */
  if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
    return t;

  if (TREE_CODE (t) == ADDR_EXPR)
    recompute_tree_invariant_for_addr_expr (t);

  *walk_subtrees = !TYPE_P (t) && !DECL_P (t);
  return NULL_TREE;
}

/* Prepend TO = FROM assignment before *GSI_P.  */

static void
expand_omp_build_assign (gimple_stmt_iterator *gsi_p, tree to, tree from)
{
  bool simple_p = DECL_P (to) && TREE_ADDRESSABLE (to);
  from = force_gimple_operand_gsi (gsi_p, from, simple_p, NULL_TREE,
                                   true, GSI_SAME_STMT);
  gimple stmt = gimple_build_assign (to, from);
  gsi_insert_before (gsi_p, stmt, GSI_SAME_STMT);
  if (walk_tree (&from, expand_omp_regimplify_p, NULL, NULL)
      || walk_tree (&to, expand_omp_regimplify_p, NULL, NULL))
    {
      gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
      gimple_regimplify_operands (stmt, &gsi);
    }
}

/* Expand the OpenMP parallel or task directive starting at REGION.  */

static void
expand_omp_taskreg (struct omp_region *region)
{
  basic_block entry_bb, exit_bb, new_bb;
  struct function *child_cfun;
  tree child_fn, block, t;
  gimple_stmt_iterator gsi;
  gimple entry_stmt, stmt;
  edge e;
  vec<tree, va_gc> *ws_args;

  entry_stmt = last_stmt (region->entry);
  child_fn = gimple_omp_taskreg_child_fn (entry_stmt);
  child_cfun = DECL_STRUCT_FUNCTION (child_fn);

  entry_bb = region->entry;
  if (gimple_code (entry_stmt) == GIMPLE_OMP_TASK)
    exit_bb = region->cont;
  else
    exit_bb = region->exit;

  bool is_cilk_for
    = (flag_cilkplus
       && gimple_code (entry_stmt) == GIMPLE_OMP_PARALLEL
       && find_omp_clause (gimple_omp_parallel_clauses (entry_stmt),
                           OMP_CLAUSE__CILK_FOR_COUNT_) != NULL_TREE);

  if (is_cilk_for)
    /* If it is a _Cilk_for statement, it is modelled *like* a parallel for,
       and the inner statement contains the name of the built-in function
       and grain.  */
    ws_args = region->inner->ws_args;
  else if (is_combined_parallel (region))
    ws_args = region->ws_args;
  else
    ws_args = NULL;

  if (child_cfun->cfg)
    {
      /* Due to inlining, it may happen that we have already outlined
         the region, in which case all we need to do is make the
         sub-graph unreachable and emit the parallel call.  */
      edge entry_succ_e, exit_succ_e;

      entry_succ_e = single_succ_edge (entry_bb);

      gsi = gsi_last_bb (entry_bb);
      gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_PARALLEL
                  || gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_TASK);
      gsi_remove (&gsi, true);

      new_bb = entry_bb;
      if (exit_bb)
        {
          exit_succ_e = single_succ_edge (exit_bb);
          make_edge (new_bb, exit_succ_e->dest, EDGE_FALLTHRU);
        }
      remove_edge_and_dominated_blocks (entry_succ_e);
    }
  else
    {
      unsigned srcidx, dstidx, num;

      /* If the parallel region needs data sent from the parent
         function, then the very first statement (except possible
         tree profile counter updates) of the parallel body
         is a copy assignment .OMP_DATA_I = &.OMP_DATA_O.  Since
         &.OMP_DATA_O is passed as an argument to the child function,
         we need to replace it with the argument as seen by the child
         function.

         In most cases, this will end up being the identity assignment
         .OMP_DATA_I = .OMP_DATA_I.  However, if the parallel body had
         a function call that has been inlined, the original PARM_DECL
         .OMP_DATA_I may have been converted into a different local
         variable.  In which case, we need to keep the assignment.  */
      if (gimple_omp_taskreg_data_arg (entry_stmt))
        {
          basic_block entry_succ_bb
            = single_succ_p (entry_bb) ? single_succ (entry_bb)
                                       : FALLTHRU_EDGE (entry_bb)->dest;
          tree arg;
          gimple parcopy_stmt = NULL;

          for (gsi = gsi_start_bb (entry_succ_bb); ; gsi_next (&gsi))
            {
              gimple stmt;

              gcc_assert (!gsi_end_p (gsi));
              stmt = gsi_stmt (gsi);
              if (gimple_code (stmt) != GIMPLE_ASSIGN)
                continue;

              if (gimple_num_ops (stmt) == 2)
                {
                  tree arg = gimple_assign_rhs1 (stmt);

                  /* We're ignore the subcode because we're
                     effectively doing a STRIP_NOPS.  */

                  if (TREE_CODE (arg) == ADDR_EXPR
                      && TREE_OPERAND (arg, 0)
                        == gimple_omp_taskreg_data_arg (entry_stmt))
                    {
                      parcopy_stmt = stmt;
                      break;
                    }
                }
            }

          gcc_assert (parcopy_stmt != NULL);
          arg = DECL_ARGUMENTS (child_fn);

          if (!gimple_in_ssa_p (cfun))
            {
              if (gimple_assign_lhs (parcopy_stmt) == arg)
                gsi_remove (&gsi, true);
              else
                {
                  /* ?? Is setting the subcode really necessary ??  */
                  gimple_omp_set_subcode (parcopy_stmt, TREE_CODE (arg));
                  gimple_assign_set_rhs1 (parcopy_stmt, arg);
                }
            }
          else
            {
              tree lhs = gimple_assign_lhs (parcopy_stmt);
              gcc_assert (SSA_NAME_VAR (lhs) == arg);
              /* We'd like to set the rhs to the default def in the child_fn,
                 but it's too early to create ssa names in the child_fn.
                 Instead, we set the rhs to the parm.  In
                 move_sese_region_to_fn, we introduce a default def for the
                 parm, map the parm to it's default def, and once we encounter
                 this stmt, replace the parm with the default def.  */
              gimple_assign_set_rhs1 (parcopy_stmt, arg);
              update_stmt (parcopy_stmt);
            }
        }

      /* Declare local variables needed in CHILD_CFUN.  */
      block = DECL_INITIAL (child_fn);
      BLOCK_VARS (block) = vec2chain (child_cfun->local_decls);
      /* The gimplifier could record temporaries in parallel/task block
         rather than in containing function's local_decls chain,
         which would mean cgraph missed finalizing them.  Do it now.  */
      for (t = BLOCK_VARS (block); t; t = DECL_CHAIN (t))
        if (TREE_CODE (t) == VAR_DECL
            && TREE_STATIC (t)
            && !DECL_EXTERNAL (t))
          varpool_node::finalize_decl (t);
      DECL_SAVED_TREE (child_fn) = NULL;
      /* We'll create a CFG for child_fn, so no gimple body is needed.  */
      gimple_set_body (child_fn, NULL);
      TREE_USED (block) = 1;

      /* Reset DECL_CONTEXT on function arguments.  */
      for (t = DECL_ARGUMENTS (child_fn); t; t = DECL_CHAIN (t))
        DECL_CONTEXT (t) = child_fn;

      /* Split ENTRY_BB at GIMPLE_OMP_PARALLEL or GIMPLE_OMP_TASK,
         so that it can be moved to the child function.  */
      gsi = gsi_last_bb (entry_bb);
      stmt = gsi_stmt (gsi);
      gcc_assert (stmt && (gimple_code (stmt) == GIMPLE_OMP_PARALLEL
                           || gimple_code (stmt) == GIMPLE_OMP_TASK));
      e = split_block (entry_bb, stmt);
      gsi_remove (&gsi, true);
      entry_bb = e->dest;
      edge e2 = NULL;
      if (gimple_code (entry_stmt) == GIMPLE_OMP_PARALLEL)
        single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;
      else
        {
          e2 = make_edge (e->src, BRANCH_EDGE (entry_bb)->dest, EDGE_ABNORMAL);
          gcc_assert (e2->dest == region->exit);
          remove_edge (BRANCH_EDGE (entry_bb));
          set_immediate_dominator (CDI_DOMINATORS, e2->dest, e->src);
          gsi = gsi_last_bb (region->exit);
          gcc_assert (!gsi_end_p (gsi)
                      && gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_RETURN);
          gsi_remove (&gsi, true);
        }

      /* Convert GIMPLE_OMP_{RETURN,CONTINUE} into a RETURN_EXPR.  */
      if (exit_bb)
        {
          gsi = gsi_last_bb (exit_bb);
          gcc_assert (!gsi_end_p (gsi)
                      && (gimple_code (gsi_stmt (gsi))
                          == (e2 ? GIMPLE_OMP_CONTINUE : GIMPLE_OMP_RETURN)));
          stmt = gimple_build_return (NULL);
          gsi_insert_after (&gsi, stmt, GSI_SAME_STMT);
          gsi_remove (&gsi, true);
        }

      /* Move the parallel region into CHILD_CFUN.  */

      if (gimple_in_ssa_p (cfun))
        {
          init_tree_ssa (child_cfun);
          init_ssa_operands (child_cfun);
          child_cfun->gimple_df->in_ssa_p = true;
          block = NULL_TREE;
        }
      else
        block = gimple_block (entry_stmt);

      new_bb = move_sese_region_to_fn (child_cfun, entry_bb, exit_bb, block);
      if (exit_bb)
        single_succ_edge (new_bb)->flags = EDGE_FALLTHRU;
      if (e2)
        {
          basic_block dest_bb = e2->dest;
          if (!exit_bb)
            make_edge (new_bb, dest_bb, EDGE_FALLTHRU);
          remove_edge (e2);
          set_immediate_dominator (CDI_DOMINATORS, dest_bb, new_bb);
        }
      /* When the OMP expansion process cannot guarantee an up-to-date
         loop tree arrange for the child function to fixup loops.  */
      if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
        child_cfun->x_current_loops->state |= LOOPS_NEED_FIXUP;

      /* Remove non-local VAR_DECLs from child_cfun->local_decls list.  */
      num = vec_safe_length (child_cfun->local_decls);
      for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
        {
          t = (*child_cfun->local_decls)[srcidx];
          if (DECL_CONTEXT (t) == cfun->decl)
            continue;
          if (srcidx != dstidx)
            (*child_cfun->local_decls)[dstidx] = t;
          dstidx++;
        }
      if (dstidx != num)
        vec_safe_truncate (child_cfun->local_decls, dstidx);

      /* Inform the callgraph about the new function.  */
      child_cfun->curr_properties = cfun->curr_properties;
      child_cfun->has_simduid_loops |= cfun->has_simduid_loops;
      child_cfun->has_force_vectorize_loops |= cfun->has_force_vectorize_loops;
      cgraph_node *node = cgraph_node::get_create (child_fn);
      node->parallelized_function = 1;
      cgraph_node::add_new_function (child_fn, true);

      /* Fix the callgraph edges for child_cfun.  Those for cfun will be
         fixed in a following pass.  */
      push_cfun (child_cfun);
      if (optimize)
        optimize_omp_library_calls (entry_stmt);
      cgraph_edge::rebuild_edges ();

      /* Some EH regions might become dead, see PR34608.  If
         pass_cleanup_cfg isn't the first pass to happen with the
         new child, these dead EH edges might cause problems.
         Clean them up now.  */
      if (flag_exceptions)
        {
          basic_block bb;
          bool changed = false;

          FOR_EACH_BB_FN (bb, cfun)
            changed |= gimple_purge_dead_eh_edges (bb);
          if (changed)
            cleanup_tree_cfg ();
        }
      if (gimple_in_ssa_p (cfun))
        update_ssa (TODO_update_ssa);
#ifdef ENABLE_CHECKING
      if (!loops_state_satisfies_p (LOOPS_NEED_FIXUP))
        verify_loop_structure ();
#endif
      pop_cfun ();
    }

  /* Emit a library call to launch the children threads.  */
  if (is_cilk_for)
    expand_cilk_for_call (new_bb,
                          as_a <gomp_parallel *> (entry_stmt), ws_args);
  else if (gimple_code (entry_stmt) == GIMPLE_OMP_PARALLEL)
    expand_parallel_call (region, new_bb,
                          as_a <gomp_parallel *> (entry_stmt), ws_args);
  else
    expand_task_call (new_bb, as_a <gomp_task *> (entry_stmt));
  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_only_virtuals);
}


/* Helper function for expand_omp_{for_*,simd}.  If this is the outermost
   of the combined collapse > 1 loop constructs, generate code like:
        if (__builtin_expect (N32 cond3 N31, 0)) goto ZERO_ITER_BB;
        if (cond3 is <)
          adj = STEP3 - 1;
        else
          adj = STEP3 + 1;
        count3 = (adj + N32 - N31) / STEP3;
        if (__builtin_expect (N22 cond2 N21, 0)) goto ZERO_ITER_BB;
        if (cond2 is <)
          adj = STEP2 - 1;
        else
          adj = STEP2 + 1;
        count2 = (adj + N22 - N21) / STEP2;
        if (__builtin_expect (N12 cond1 N11, 0)) goto ZERO_ITER_BB;
        if (cond1 is <)
          adj = STEP1 - 1;
        else
          adj = STEP1 + 1;
        count1 = (adj + N12 - N11) / STEP1;
        count = count1 * count2 * count3;
   Furthermore, if ZERO_ITER_BB is NULL, create a BB which does:
        count = 0;
   and set ZERO_ITER_BB to that bb.  If this isn't the outermost
   of the combined loop constructs, just initialize COUNTS array
   from the _looptemp_ clauses.  */

/* NOTE: It *could* be better to moosh all of the BBs together,
   creating one larger BB with all the computation and the unexpected
   jump at the end.  I.e.

   bool zero3, zero2, zero1, zero;

   zero3 = N32 c3 N31;
   count3 = (N32 - N31) /[cl] STEP3;
   zero2 = N22 c2 N21;
   count2 = (N22 - N21) /[cl] STEP2;
   zero1 = N12 c1 N11;
   count1 = (N12 - N11) /[cl] STEP1;
   zero = zero3 || zero2 || zero1;
   count = count1 * count2 * count3;
   if (__builtin_expect(zero, false)) goto zero_iter_bb;

   After all, we expect the zero=false, and thus we expect to have to
   evaluate all of the comparison expressions, so short-circuiting
   oughtn't be a win.  Since the condition isn't protecting a
   denominator, we're not concerned about divide-by-zero, so we can
   fully evaluate count even if a numerator turned out to be wrong.

   It seems like putting this all together would create much better
   scheduling opportunities, and less pressure on the chip's branch
   predictor.  */

static void
expand_omp_for_init_counts (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
                            basic_block &entry_bb, tree *counts,
                            basic_block &zero_iter_bb, int &first_zero_iter,
                            basic_block &l2_dom_bb)
{
  tree t, type = TREE_TYPE (fd->loop.v);
  edge e, ne;
  int i;

  /* Collapsed loops need work for expansion into SSA form.  */
  gcc_assert (!gimple_in_ssa_p (cfun));

  if (gimple_omp_for_combined_into_p (fd->for_stmt)
      && TREE_CODE (fd->loop.n2) != INTEGER_CST)
    {
      /* First two _looptemp_ clauses are for istart/iend, counts[0]
         isn't supposed to be handled, as the inner loop doesn't
         use it.  */
      tree innerc = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                     OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      for (i = 0; i < fd->collapse; i++)
        {
          innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                    OMP_CLAUSE__LOOPTEMP_);
          gcc_assert (innerc);
          if (i)
            counts[i] = OMP_CLAUSE_DECL (innerc);
          else
            counts[0] = NULL_TREE;
        }
      return;
    }

  for (i = 0; i < fd->collapse; i++)
    {
      tree itype = TREE_TYPE (fd->loops[i].v);

      if (SSA_VAR_P (fd->loop.n2)
          && ((t = fold_binary (fd->loops[i].cond_code, boolean_type_node,
                                fold_convert (itype, fd->loops[i].n1),
                                fold_convert (itype, fd->loops[i].n2)))
              == NULL_TREE || !integer_onep (t)))
        {
          gcond *cond_stmt;
          tree n1, n2;
          n1 = fold_convert (itype, unshare_expr (fd->loops[i].n1));
          n1 = force_gimple_operand_gsi (gsi, n1, true, NULL_TREE,
                                         true, GSI_SAME_STMT);
          n2 = fold_convert (itype, unshare_expr (fd->loops[i].n2));
          n2 = force_gimple_operand_gsi (gsi, n2, true, NULL_TREE,
                                         true, GSI_SAME_STMT);
          cond_stmt = gimple_build_cond (fd->loops[i].cond_code, n1, n2,
                                         NULL_TREE, NULL_TREE);
          gsi_insert_before (gsi, cond_stmt, GSI_SAME_STMT);
          if (walk_tree (gimple_cond_lhs_ptr (cond_stmt),
                         expand_omp_regimplify_p, NULL, NULL)
              || walk_tree (gimple_cond_rhs_ptr (cond_stmt),
                            expand_omp_regimplify_p, NULL, NULL))
            {
              *gsi = gsi_for_stmt (cond_stmt);
              gimple_regimplify_operands (cond_stmt, gsi);
            }
          e = split_block (entry_bb, cond_stmt);
          if (zero_iter_bb == NULL)
            {
              gassign *assign_stmt;
              first_zero_iter = i;
              zero_iter_bb = create_empty_bb (entry_bb);
              add_bb_to_loop (zero_iter_bb, entry_bb->loop_father);
              *gsi = gsi_after_labels (zero_iter_bb);
              assign_stmt = gimple_build_assign (fd->loop.n2,
                                                 build_zero_cst (type));
              gsi_insert_before (gsi, assign_stmt, GSI_SAME_STMT);
              set_immediate_dominator (CDI_DOMINATORS, zero_iter_bb,
                                       entry_bb);
            }
          ne = make_edge (entry_bb, zero_iter_bb, EDGE_FALSE_VALUE);
          ne->probability = REG_BR_PROB_BASE / 2000 - 1;
          e->flags = EDGE_TRUE_VALUE;
          e->probability = REG_BR_PROB_BASE - ne->probability;
          if (l2_dom_bb == NULL)
            l2_dom_bb = entry_bb;
          entry_bb = e->dest;
          *gsi = gsi_last_bb (entry_bb);
        }

      if (POINTER_TYPE_P (itype))
        itype = signed_type_for (itype);
      t = build_int_cst (itype, (fd->loops[i].cond_code == LT_EXPR
                                 ? -1 : 1));
      t = fold_build2 (PLUS_EXPR, itype,
                       fold_convert (itype, fd->loops[i].step), t);
      t = fold_build2 (PLUS_EXPR, itype, t,
                       fold_convert (itype, fd->loops[i].n2));
      t = fold_build2 (MINUS_EXPR, itype, t,
                       fold_convert (itype, fd->loops[i].n1));
      /* ?? We could probably use CEIL_DIV_EXPR instead of
         TRUNC_DIV_EXPR and adjusting by hand.  Unless we can't
         generate the same code in the end because generically we
         don't know that the values involved must be negative for
         GT??  */
      if (TYPE_UNSIGNED (itype) && fd->loops[i].cond_code == GT_EXPR)
        t = fold_build2 (TRUNC_DIV_EXPR, itype,
                         fold_build1 (NEGATE_EXPR, itype, t),
                         fold_build1 (NEGATE_EXPR, itype,
                                      fold_convert (itype,
                                                    fd->loops[i].step)));
      else
        t = fold_build2 (TRUNC_DIV_EXPR, itype, t,
                         fold_convert (itype, fd->loops[i].step));
      t = fold_convert (type, t);
      if (TREE_CODE (t) == INTEGER_CST)
        counts[i] = t;
      else
        {
          counts[i] = create_tmp_reg (type, ".count");
          expand_omp_build_assign (gsi, counts[i], t);
        }
      if (SSA_VAR_P (fd->loop.n2))
        {
          if (i == 0)
            t = counts[0];
          else
            t = fold_build2 (MULT_EXPR, type, fd->loop.n2, counts[i]);
          expand_omp_build_assign (gsi, fd->loop.n2, t);
        }
    }
}


/* Helper function for expand_omp_{for_*,simd}.  Generate code like:
        T = V;
        V3 = N31 + (T % count3) * STEP3;
        T = T / count3;
        V2 = N21 + (T % count2) * STEP2;
        T = T / count2;
        V1 = N11 + T * STEP1;
   if this loop doesn't have an inner loop construct combined with it.
   If it does have an inner loop construct combined with it and the
   iteration count isn't known constant, store values from counts array
   into its _looptemp_ temporaries instead.  */

static void
expand_omp_for_init_vars (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
                          tree *counts, gimple inner_stmt, tree startvar)
{
  int i;
  if (gimple_omp_for_combined_p (fd->for_stmt))
    {
      /* If fd->loop.n2 is constant, then no propagation of the counts
         is needed, they are constant.  */
      if (TREE_CODE (fd->loop.n2) == INTEGER_CST)
        return;

      tree clauses = gimple_code (inner_stmt) == GIMPLE_OMP_PARALLEL
                     ? gimple_omp_parallel_clauses (inner_stmt)
                     : gimple_omp_for_clauses (inner_stmt);
      /* First two _looptemp_ clauses are for istart/iend, counts[0]
         isn't supposed to be handled, as the inner loop doesn't
         use it.  */
      tree innerc = find_omp_clause (clauses, OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      for (i = 0; i < fd->collapse; i++)
        {
          innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                    OMP_CLAUSE__LOOPTEMP_);
          gcc_assert (innerc);
          if (i)
            {
              tree tem = OMP_CLAUSE_DECL (innerc);
              tree t = fold_convert (TREE_TYPE (tem), counts[i]);
              t = force_gimple_operand_gsi (gsi, t, false, NULL_TREE,
                                            false, GSI_CONTINUE_LINKING);
              gassign *stmt = gimple_build_assign (tem, t);
              gsi_insert_after (gsi, stmt, GSI_CONTINUE_LINKING);
            }
        }
      return;
    }

  tree type = TREE_TYPE (fd->loop.v);
  tree tem = create_tmp_reg (type, ".tem");
  gassign *stmt = gimple_build_assign (tem, startvar);
  gsi_insert_after (gsi, stmt, GSI_CONTINUE_LINKING);

  for (i = fd->collapse - 1; i >= 0; i--)
    {
      tree vtype = TREE_TYPE (fd->loops[i].v), itype, t;
      itype = vtype;
      if (POINTER_TYPE_P (vtype))
        itype = signed_type_for (vtype);
      if (i != 0)
        t = fold_build2 (TRUNC_MOD_EXPR, type, tem, counts[i]);
      else
        t = tem;
      t = fold_convert (itype, t);
      t = fold_build2 (MULT_EXPR, itype, t,
                       fold_convert (itype, fd->loops[i].step));
      if (POINTER_TYPE_P (vtype))
        t = fold_build_pointer_plus (fd->loops[i].n1, t);
      else
        t = fold_build2 (PLUS_EXPR, itype, fd->loops[i].n1, t);
      t = force_gimple_operand_gsi (gsi, t,
                                    DECL_P (fd->loops[i].v)
                                    && TREE_ADDRESSABLE (fd->loops[i].v),
                                    NULL_TREE, false,
                                    GSI_CONTINUE_LINKING);
      stmt = gimple_build_assign (fd->loops[i].v, t);
      gsi_insert_after (gsi, stmt, GSI_CONTINUE_LINKING);
      if (i != 0)
        {
          t = fold_build2 (TRUNC_DIV_EXPR, type, tem, counts[i]);
          t = force_gimple_operand_gsi (gsi, t, false, NULL_TREE,
                                        false, GSI_CONTINUE_LINKING);
          stmt = gimple_build_assign (tem, t);
          gsi_insert_after (gsi, stmt, GSI_CONTINUE_LINKING);
        }
    }
}


/* Helper function for expand_omp_for_*.  Generate code like:
    L10:
        V3 += STEP3;
        if (V3 cond3 N32) goto BODY_BB; else goto L11;
    L11:
        V3 = N31;
        V2 += STEP2;
        if (V2 cond2 N22) goto BODY_BB; else goto L12;
    L12:
        V2 = N21;
        V1 += STEP1;
        goto BODY_BB;  */

static basic_block
extract_omp_for_update_vars (struct omp_for_data *fd, basic_block cont_bb,
                             basic_block body_bb)
{
  basic_block last_bb, bb, collapse_bb = NULL;
  int i;
  gimple_stmt_iterator gsi;
  edge e;
  tree t;
  gimple stmt;

  last_bb = cont_bb;
  for (i = fd->collapse - 1; i >= 0; i--)
    {
      tree vtype = TREE_TYPE (fd->loops[i].v);

      bb = create_empty_bb (last_bb);
      add_bb_to_loop (bb, last_bb->loop_father);
      gsi = gsi_start_bb (bb);

      if (i < fd->collapse - 1)
        {
          e = make_edge (last_bb, bb, EDGE_FALSE_VALUE);
          e->probability = REG_BR_PROB_BASE / 8;

          t = fd->loops[i + 1].n1;
          t = force_gimple_operand_gsi (&gsi, t,
                                        DECL_P (fd->loops[i + 1].v)
                                        && TREE_ADDRESSABLE (fd->loops[i
                                                                       + 1].v),
                                        NULL_TREE, false,
                                        GSI_CONTINUE_LINKING);
          stmt = gimple_build_assign (fd->loops[i + 1].v, t);
          gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
        }
      else
        collapse_bb = bb;

      set_immediate_dominator (CDI_DOMINATORS, bb, last_bb);

      if (POINTER_TYPE_P (vtype))
        t = fold_build_pointer_plus (fd->loops[i].v, fd->loops[i].step);
      else
        t = fold_build2 (PLUS_EXPR, vtype, fd->loops[i].v, fd->loops[i].step);
      t = force_gimple_operand_gsi (&gsi, t,
                                    DECL_P (fd->loops[i].v)
                                    && TREE_ADDRESSABLE (fd->loops[i].v),
                                    NULL_TREE, false, GSI_CONTINUE_LINKING);
      stmt = gimple_build_assign (fd->loops[i].v, t);
      gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

      if (i > 0)
        {
          t = fd->loops[i].n2;
          t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                        false, GSI_CONTINUE_LINKING);
          tree v = fd->loops[i].v;
          if (DECL_P (v) && TREE_ADDRESSABLE (v))
            v = force_gimple_operand_gsi (&gsi, v, true, NULL_TREE,
                                          false, GSI_CONTINUE_LINKING);
          t = fold_build2 (fd->loops[i].cond_code, boolean_type_node, v, t);
          stmt = gimple_build_cond_empty (t);
          gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
          e = make_edge (bb, body_bb, EDGE_TRUE_VALUE);
          e->probability = REG_BR_PROB_BASE * 7 / 8;
        }
      else
        make_edge (bb, body_bb, EDGE_FALLTHRU);
      last_bb = bb;
    }

  return collapse_bb;
}


/* A subroutine of expand_omp_for.  Generate code for a parallel
   loop with any schedule.  Given parameters:

        for (V = N1; V cond N2; V += STEP) BODY;

   where COND is "<" or ">", we generate pseudocode

        more = GOMP_loop_foo_start (N1, N2, STEP, CHUNK, &istart0, &iend0);
        if (more) goto L0; else goto L3;
    L0:
        V = istart0;
        iend = iend0;
    L1:
        BODY;
        V += STEP;
        if (V cond iend) goto L1; else goto L2;
    L2:
        if (GOMP_loop_foo_next (&istart0, &iend0)) goto L0; else goto L3;
    L3:

    If this is a combined omp parallel loop, instead of the call to
    GOMP_loop_foo_start, we call GOMP_loop_foo_next.
    If this is gimple_omp_for_combined_p loop, then instead of assigning
    V and iend in L0 we assign the first two _looptemp_ clause decls of the
    inner GIMPLE_OMP_FOR and V += STEP; and
    if (V cond iend) goto L1; else goto L2; are removed.

    For collapsed loops, given parameters:
      collapse(3)
      for (V1 = N11; V1 cond1 N12; V1 += STEP1)
        for (V2 = N21; V2 cond2 N22; V2 += STEP2)
          for (V3 = N31; V3 cond3 N32; V3 += STEP3)
            BODY;

    we generate pseudocode

        if (__builtin_expect (N32 cond3 N31, 0)) goto Z0;
        if (cond3 is <)
          adj = STEP3 - 1;
        else
          adj = STEP3 + 1;
        count3 = (adj + N32 - N31) / STEP3;
        if (__builtin_expect (N22 cond2 N21, 0)) goto Z0;
        if (cond2 is <)
          adj = STEP2 - 1;
        else
          adj = STEP2 + 1;
        count2 = (adj + N22 - N21) / STEP2;
        if (__builtin_expect (N12 cond1 N11, 0)) goto Z0;
        if (cond1 is <)
          adj = STEP1 - 1;
        else
          adj = STEP1 + 1;
        count1 = (adj + N12 - N11) / STEP1;
        count = count1 * count2 * count3;
        goto Z1;
    Z0:
        count = 0;
    Z1:
        more = GOMP_loop_foo_start (0, count, 1, CHUNK, &istart0, &iend0);
        if (more) goto L0; else goto L3;
    L0:
        V = istart0;
        T = V;
        V3 = N31 + (T % count3) * STEP3;
        T = T / count3;
        V2 = N21 + (T % count2) * STEP2;
        T = T / count2;
        V1 = N11 + T * STEP1;
        iend = iend0;
    L1:
        BODY;
        V += 1;
        if (V < iend) goto L10; else goto L2;
    L10:
        V3 += STEP3;
        if (V3 cond3 N32) goto L1; else goto L11;
    L11:
        V3 = N31;
        V2 += STEP2;
        if (V2 cond2 N22) goto L1; else goto L12;
    L12:
        V2 = N21;
        V1 += STEP1;
        goto L1;
    L2:
        if (GOMP_loop_foo_next (&istart0, &iend0)) goto L0; else goto L3;
    L3:

      */

static void
expand_omp_for_generic (struct omp_region *region,
                        struct omp_for_data *fd,
                        enum built_in_function start_fn,
                        enum built_in_function next_fn,
                        gimple inner_stmt)
{
  tree type, istart0, iend0, iend;
  tree t, vmain, vback, bias = NULL_TREE;
  basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb, collapse_bb;
  basic_block l2_bb = NULL, l3_bb = NULL;
  gimple_stmt_iterator gsi;
  gassign *assign_stmt;
  bool in_combined_parallel = is_combined_parallel (region);
  bool broken_loop = region->cont == NULL;
  edge e, ne;
  tree *counts = NULL;
  int i;

  gcc_assert (!broken_loop || !in_combined_parallel);
  gcc_assert (fd->iter_type == long_integer_type_node
              || !in_combined_parallel);

  type = TREE_TYPE (fd->loop.v);
  istart0 = create_tmp_var (fd->iter_type, ".istart0");
  iend0 = create_tmp_var (fd->iter_type, ".iend0");
  TREE_ADDRESSABLE (istart0) = 1;
  TREE_ADDRESSABLE (iend0) = 1;

  /* See if we need to bias by LLONG_MIN.  */
  if (fd->iter_type == long_long_unsigned_type_node
      && TREE_CODE (type) == INTEGER_TYPE
      && !TYPE_UNSIGNED (type))
    {
      tree n1, n2;

      if (fd->loop.cond_code == LT_EXPR)
        {
          n1 = fd->loop.n1;
          n2 = fold_build2 (PLUS_EXPR, type, fd->loop.n2, fd->loop.step);
        }
      else
        {
          n1 = fold_build2 (MINUS_EXPR, type, fd->loop.n2, fd->loop.step);
          n2 = fd->loop.n1;
        }
      if (TREE_CODE (n1) != INTEGER_CST
          || TREE_CODE (n2) != INTEGER_CST
          || ((tree_int_cst_sgn (n1) < 0) ^ (tree_int_cst_sgn (n2) < 0)))
        bias = fold_convert (fd->iter_type, TYPE_MIN_VALUE (type));
    }

  entry_bb = region->entry;
  cont_bb = region->cont;
  collapse_bb = NULL;
  gcc_assert (EDGE_COUNT (entry_bb->succs) == 2);
  gcc_assert (broken_loop
              || BRANCH_EDGE (entry_bb)->dest == FALLTHRU_EDGE (cont_bb)->dest);
  l0_bb = split_edge (FALLTHRU_EDGE (entry_bb));
  l1_bb = single_succ (l0_bb);
  if (!broken_loop)
    {
      l2_bb = create_empty_bb (cont_bb);
      gcc_assert (BRANCH_EDGE (cont_bb)->dest == l1_bb);
      gcc_assert (EDGE_COUNT (cont_bb->succs) == 2);
    }
  else
    l2_bb = NULL;
  l3_bb = BRANCH_EDGE (entry_bb)->dest;
  exit_bb = region->exit;

  gsi = gsi_last_bb (entry_bb);

  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);
  if (fd->collapse > 1)
    {
      int first_zero_iter = -1;
      basic_block zero_iter_bb = NULL, l2_dom_bb = NULL;

      counts = XALLOCAVEC (tree, fd->collapse);
      expand_omp_for_init_counts (fd, &gsi, entry_bb, counts,
                                  zero_iter_bb, first_zero_iter,
                                  l2_dom_bb);

      if (zero_iter_bb)
        {
          /* Some counts[i] vars might be uninitialized if
             some loop has zero iterations.  But the body shouldn't
             be executed in that case, so just avoid uninit warnings.  */
          for (i = first_zero_iter; i < fd->collapse; i++)
            if (SSA_VAR_P (counts[i]))
              TREE_NO_WARNING (counts[i]) = 1;
          gsi_prev (&gsi);
          e = split_block (entry_bb, gsi_stmt (gsi));
          entry_bb = e->dest;
          make_edge (zero_iter_bb, entry_bb, EDGE_FALLTHRU);
          gsi = gsi_last_bb (entry_bb);
          set_immediate_dominator (CDI_DOMINATORS, entry_bb,
                                   get_immediate_dominator (CDI_DOMINATORS,
                                                            zero_iter_bb));
        }
    }
  if (in_combined_parallel)
    {
      /* In a combined parallel loop, emit a call to
         GOMP_loop_foo_next.  */
      t = build_call_expr (builtin_decl_explicit (next_fn), 2,
                           build_fold_addr_expr (istart0),
                           build_fold_addr_expr (iend0));
    }
  else
    {
      tree t0, t1, t2, t3, t4;
      /* If this is not a combined parallel loop, emit a call to
         GOMP_loop_foo_start in ENTRY_BB.  */
      t4 = build_fold_addr_expr (iend0);
      t3 = build_fold_addr_expr (istart0);
      t2 = fold_convert (fd->iter_type, fd->loop.step);
      t1 = fd->loop.n2;
      t0 = fd->loop.n1;
      if (gimple_omp_for_combined_into_p (fd->for_stmt))
        {
          tree innerc = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                         OMP_CLAUSE__LOOPTEMP_);
          gcc_assert (innerc);
          t0 = OMP_CLAUSE_DECL (innerc);
          innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                    OMP_CLAUSE__LOOPTEMP_);
          gcc_assert (innerc);
          t1 = OMP_CLAUSE_DECL (innerc);
        }
      if (POINTER_TYPE_P (TREE_TYPE (t0))
          && TYPE_PRECISION (TREE_TYPE (t0))
             != TYPE_PRECISION (fd->iter_type))
        {
          /* Avoid casting pointers to integer of a different size.  */
          tree itype = signed_type_for (type);
          t1 = fold_convert (fd->iter_type, fold_convert (itype, t1));
          t0 = fold_convert (fd->iter_type, fold_convert (itype, t0));
        }
      else
        {
          t1 = fold_convert (fd->iter_type, t1);
          t0 = fold_convert (fd->iter_type, t0);
        }
      if (bias)
        {
          t1 = fold_build2 (PLUS_EXPR, fd->iter_type, t1, bias);
          t0 = fold_build2 (PLUS_EXPR, fd->iter_type, t0, bias);
        }
      if (fd->iter_type == long_integer_type_node)
        {
          if (fd->chunk_size)
            {
              t = fold_convert (fd->iter_type, fd->chunk_size);
              t = build_call_expr (builtin_decl_explicit (start_fn),
                                   6, t0, t1, t2, t, t3, t4);
            }
          else
            t = build_call_expr (builtin_decl_explicit (start_fn),
                                 5, t0, t1, t2, t3, t4);
        }
      else
        {
          tree t5;
          tree c_bool_type;
          tree bfn_decl;

          /* The GOMP_loop_ull_*start functions have additional boolean
             argument, true for < loops and false for > loops.
             In Fortran, the C bool type can be different from
             boolean_type_node.  */
          bfn_decl = builtin_decl_explicit (start_fn);
          c_bool_type = TREE_TYPE (TREE_TYPE (bfn_decl));
          t5 = build_int_cst (c_bool_type,
                              fd->loop.cond_code == LT_EXPR ? 1 : 0);
          if (fd->chunk_size)
            {
              tree bfn_decl = builtin_decl_explicit (start_fn);
              t = fold_convert (fd->iter_type, fd->chunk_size);
              t = build_call_expr (bfn_decl, 7, t5, t0, t1, t2, t, t3, t4);
            }
          else
            t = build_call_expr (builtin_decl_explicit (start_fn),
                                 6, t5, t0, t1, t2, t3, t4);
        }
    }
  if (TREE_TYPE (t) != boolean_type_node)
    t = fold_build2 (NE_EXPR, boolean_type_node,
                     t, build_int_cst (TREE_TYPE (t), 0));
  t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                true, GSI_SAME_STMT);
  gsi_insert_after (&gsi, gimple_build_cond_empty (t), GSI_SAME_STMT);

  /* Remove the GIMPLE_OMP_FOR statement.  */
  gsi_remove (&gsi, true);

  /* Iteration setup for sequential loop goes in L0_BB.  */
  tree startvar = fd->loop.v;
  tree endvar = NULL_TREE;

  if (gimple_omp_for_combined_p (fd->for_stmt))
    {
      gcc_assert (gimple_code (inner_stmt) == GIMPLE_OMP_FOR
                  && gimple_omp_for_kind (inner_stmt)
                     == GF_OMP_FOR_KIND_SIMD);
      tree innerc = find_omp_clause (gimple_omp_for_clauses (inner_stmt),
                                     OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      startvar = OMP_CLAUSE_DECL (innerc);
      innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      endvar = OMP_CLAUSE_DECL (innerc);
    }

  gsi = gsi_start_bb (l0_bb);
  t = istart0;
  if (bias)
    t = fold_build2 (MINUS_EXPR, fd->iter_type, t, bias);
  if (POINTER_TYPE_P (TREE_TYPE (startvar)))
    t = fold_convert (signed_type_for (TREE_TYPE (startvar)), t);
  t = fold_convert (TREE_TYPE (startvar), t);
  t = force_gimple_operand_gsi (&gsi, t,
                                DECL_P (startvar)
                                && TREE_ADDRESSABLE (startvar),
                                NULL_TREE, false, GSI_CONTINUE_LINKING);
  assign_stmt = gimple_build_assign (startvar, t);
  gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);

  t = iend0;
  if (bias)
    t = fold_build2 (MINUS_EXPR, fd->iter_type, t, bias);
  if (POINTER_TYPE_P (TREE_TYPE (startvar)))
    t = fold_convert (signed_type_for (TREE_TYPE (startvar)), t);
  t = fold_convert (TREE_TYPE (startvar), t);
  iend = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                   false, GSI_CONTINUE_LINKING);
  if (endvar)
    {
      assign_stmt = gimple_build_assign (endvar, iend);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
      if (useless_type_conversion_p (TREE_TYPE (fd->loop.v), TREE_TYPE (iend)))
        assign_stmt = gimple_build_assign (fd->loop.v, iend);
      else
        assign_stmt = gimple_build_assign (fd->loop.v, NOP_EXPR, iend);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
    }
  if (fd->collapse > 1)
    expand_omp_for_init_vars (fd, &gsi, counts, inner_stmt, startvar);

  if (!broken_loop)
    {
      /* Code to control the increment and predicate for the sequential
         loop goes in the CONT_BB.  */
      gsi = gsi_last_bb (cont_bb);
      gomp_continue *cont_stmt = as_a <gomp_continue *> (gsi_stmt (gsi));
      gcc_assert (gimple_code (cont_stmt) == GIMPLE_OMP_CONTINUE);
      vmain = gimple_omp_continue_control_use (cont_stmt);
      vback = gimple_omp_continue_control_def (cont_stmt);

      if (!gimple_omp_for_combined_p (fd->for_stmt))
        {
          if (POINTER_TYPE_P (type))
            t = fold_build_pointer_plus (vmain, fd->loop.step);
          else
            t = fold_build2 (PLUS_EXPR, type, vmain, fd->loop.step);
          t = force_gimple_operand_gsi (&gsi, t,
                                        DECL_P (vback)
                                        && TREE_ADDRESSABLE (vback),
                                        NULL_TREE, true, GSI_SAME_STMT);
          assign_stmt = gimple_build_assign (vback, t);
          gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);

          t = build2 (fd->loop.cond_code, boolean_type_node,
                      DECL_P (vback) && TREE_ADDRESSABLE (vback) ? t : vback,
                      iend);
          gcond *cond_stmt = gimple_build_cond_empty (t);
          gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
        }

      /* Remove GIMPLE_OMP_CONTINUE.  */
      gsi_remove (&gsi, true);

      if (fd->collapse > 1 && !gimple_omp_for_combined_p (fd->for_stmt))
        collapse_bb = extract_omp_for_update_vars (fd, cont_bb, l1_bb);

      /* Emit code to get the next parallel iteration in L2_BB.  */
      gsi = gsi_start_bb (l2_bb);

      t = build_call_expr (builtin_decl_explicit (next_fn), 2,
                           build_fold_addr_expr (istart0),
                           build_fold_addr_expr (iend0));
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                    false, GSI_CONTINUE_LINKING);
      if (TREE_TYPE (t) != boolean_type_node)
        t = fold_build2 (NE_EXPR, boolean_type_node,
                         t, build_int_cst (TREE_TYPE (t), 0));
      gcond *cond_stmt = gimple_build_cond_empty (t);
      gsi_insert_after (&gsi, cond_stmt, GSI_CONTINUE_LINKING);
    }

  /* Add the loop cleanup function.  */
  gsi = gsi_last_bb (exit_bb);
  if (gimple_omp_return_nowait_p (gsi_stmt (gsi)))
    t = builtin_decl_explicit (BUILT_IN_GOMP_LOOP_END_NOWAIT);
  else if (gimple_omp_return_lhs (gsi_stmt (gsi)))
    t = builtin_decl_explicit (BUILT_IN_GOMP_LOOP_END_CANCEL);
  else
    t = builtin_decl_explicit (BUILT_IN_GOMP_LOOP_END);
  gcall *call_stmt = gimple_build_call (t, 0);
  if (gimple_omp_return_lhs (gsi_stmt (gsi)))
    gimple_call_set_lhs (call_stmt, gimple_omp_return_lhs (gsi_stmt (gsi)));
  gsi_insert_after (&gsi, call_stmt, GSI_SAME_STMT);
  gsi_remove (&gsi, true);

  /* Connect the new blocks.  */
  find_edge (entry_bb, l0_bb)->flags = EDGE_TRUE_VALUE;
  find_edge (entry_bb, l3_bb)->flags = EDGE_FALSE_VALUE;

  if (!broken_loop)
    {
      gimple_seq phis;

      e = find_edge (cont_bb, l3_bb);
      ne = make_edge (l2_bb, l3_bb, EDGE_FALSE_VALUE);

      phis = phi_nodes (l3_bb);
      for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
        {
          gimple phi = gsi_stmt (gsi);
          SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, ne),
                   PHI_ARG_DEF_FROM_EDGE (phi, e));
        }
      remove_edge (e);

      make_edge (cont_bb, l2_bb, EDGE_FALSE_VALUE);
      add_bb_to_loop (l2_bb, cont_bb->loop_father);
      e = find_edge (cont_bb, l1_bb);
      if (gimple_omp_for_combined_p (fd->for_stmt))
        {
          remove_edge (e);
          e = NULL;
        }
      else if (fd->collapse > 1)
        {
          remove_edge (e);
          e = make_edge (cont_bb, collapse_bb, EDGE_TRUE_VALUE);
        }
      else
        e->flags = EDGE_TRUE_VALUE;
      if (e)
        {
          e->probability = REG_BR_PROB_BASE * 7 / 8;
          find_edge (cont_bb, l2_bb)->probability = REG_BR_PROB_BASE / 8;
        }
      else
        {
          e = find_edge (cont_bb, l2_bb);
          e->flags = EDGE_FALLTHRU;
        }
      make_edge (l2_bb, l0_bb, EDGE_TRUE_VALUE);

      set_immediate_dominator (CDI_DOMINATORS, l2_bb,
                               recompute_dominator (CDI_DOMINATORS, l2_bb));
      set_immediate_dominator (CDI_DOMINATORS, l3_bb,
                               recompute_dominator (CDI_DOMINATORS, l3_bb));
      set_immediate_dominator (CDI_DOMINATORS, l0_bb,
                               recompute_dominator (CDI_DOMINATORS, l0_bb));
      set_immediate_dominator (CDI_DOMINATORS, l1_bb,
                               recompute_dominator (CDI_DOMINATORS, l1_bb));

      struct loop *outer_loop = alloc_loop ();
      outer_loop->header = l0_bb;
      outer_loop->latch = l2_bb;
      add_loop (outer_loop, l0_bb->loop_father);

      if (!gimple_omp_for_combined_p (fd->for_stmt))
        {
          struct loop *loop = alloc_loop ();
          loop->header = l1_bb;
          /* The loop may have multiple latches.  */
          add_loop (loop, outer_loop);
        }
    }
}


/* A subroutine of expand_omp_for.  Generate code for a parallel
   loop with static schedule and no specified chunk size.  Given
   parameters:

        for (V = N1; V cond N2; V += STEP) BODY;

   where COND is "<" or ">", we generate pseudocode

        if ((__typeof (V)) -1 > 0 && N2 cond N1) goto L2;
        if (cond is <)
          adj = STEP - 1;
        else
          adj = STEP + 1;
        if ((__typeof (V)) -1 > 0 && cond is >)
          n = -(adj + N2 - N1) / -STEP;
        else
          n = (adj + N2 - N1) / STEP;
        q = n / nthreads;
        tt = n % nthreads;
        if (threadid < tt) goto L3; else goto L4;
    L3:
        tt = 0;
        q = q + 1;
    L4:
        s0 = q * threadid + tt;
        e0 = s0 + q;
        V = s0 * STEP + N1;
        if (s0 >= e0) goto L2; else goto L0;
    L0:
        e = e0 * STEP + N1;
    L1:
        BODY;
        V += STEP;
        if (V cond e) goto L1;
    L2:
*/

static void
expand_omp_for_static_nochunk (struct omp_region *region,
                               struct omp_for_data *fd,
                               gimple inner_stmt)
{
  tree n, q, s0, e0, e, t, tt, nthreads, threadid;
  tree type, itype, vmain, vback;
  basic_block entry_bb, second_bb, third_bb, exit_bb, seq_start_bb;
  basic_block body_bb, cont_bb, collapse_bb = NULL;
  basic_block fin_bb;
  gimple_stmt_iterator gsi;
  edge ep;
  bool broken_loop = region->cont == NULL;
  tree *counts = NULL;
  tree n1, n2, step;

  gcc_checking_assert ((gimple_omp_for_kind (fd->for_stmt)
                        != GF_OMP_FOR_KIND_OACC_LOOP)
                       || !inner_stmt);

  itype = type = TREE_TYPE (fd->loop.v);
  if (POINTER_TYPE_P (type))
    itype = signed_type_for (type);

  entry_bb = region->entry;
  cont_bb = region->cont;
  gcc_assert (EDGE_COUNT (entry_bb->succs) == 2);
  fin_bb = BRANCH_EDGE (entry_bb)->dest;
  gcc_assert (broken_loop
              || (fin_bb == FALLTHRU_EDGE (cont_bb)->dest));
  seq_start_bb = split_edge (FALLTHRU_EDGE (entry_bb));
  body_bb = single_succ (seq_start_bb);
  if (!broken_loop)
    {
      gcc_assert (BRANCH_EDGE (cont_bb)->dest == body_bb
                  || single_succ (BRANCH_EDGE (cont_bb)->dest) == body_bb);
      gcc_assert (EDGE_COUNT (cont_bb->succs) == 2);
    }
  exit_bb = region->exit;

  /* Iteration space partitioning goes in ENTRY_BB.  */
  gsi = gsi_last_bb (entry_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);

  if (fd->collapse > 1)
    {
      int first_zero_iter = -1;
      basic_block l2_dom_bb = NULL;

      counts = XALLOCAVEC (tree, fd->collapse);
      expand_omp_for_init_counts (fd, &gsi, entry_bb, counts,
                                  fin_bb, first_zero_iter,
                                  l2_dom_bb);
      t = NULL_TREE;
    }
  else if (gimple_omp_for_combined_into_p (fd->for_stmt))
    t = integer_one_node;
  else
    t = fold_binary (fd->loop.cond_code, boolean_type_node,
                     fold_convert (type, fd->loop.n1),
                     fold_convert (type, fd->loop.n2));
  if (fd->collapse == 1
      && TYPE_UNSIGNED (type)
      && (t == NULL_TREE || !integer_onep (t)))
    {
      n1 = fold_convert (type, unshare_expr (fd->loop.n1));
      n1 = force_gimple_operand_gsi (&gsi, n1, true, NULL_TREE,
                                     true, GSI_SAME_STMT);
      n2 = fold_convert (type, unshare_expr (fd->loop.n2));
      n2 = force_gimple_operand_gsi (&gsi, n2, true, NULL_TREE,
                                     true, GSI_SAME_STMT);
      gcond *cond_stmt = gimple_build_cond (fd->loop.cond_code, n1, n2,
                                                 NULL_TREE, NULL_TREE);
      gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
      if (walk_tree (gimple_cond_lhs_ptr (cond_stmt),
                     expand_omp_regimplify_p, NULL, NULL)
          || walk_tree (gimple_cond_rhs_ptr (cond_stmt),
                        expand_omp_regimplify_p, NULL, NULL))
        {
          gsi = gsi_for_stmt (cond_stmt);
          gimple_regimplify_operands (cond_stmt, &gsi);
        }
      ep = split_block (entry_bb, cond_stmt);
      ep->flags = EDGE_TRUE_VALUE;
      entry_bb = ep->dest;
      ep->probability = REG_BR_PROB_BASE - (REG_BR_PROB_BASE / 2000 - 1);
      ep = make_edge (ep->src, fin_bb, EDGE_FALSE_VALUE);
      ep->probability = REG_BR_PROB_BASE / 2000 - 1;
      if (gimple_in_ssa_p (cfun))
        {
          int dest_idx = find_edge (entry_bb, fin_bb)->dest_idx;
          for (gphi_iterator gpi = gsi_start_phis (fin_bb);
               !gsi_end_p (gpi); gsi_next (&gpi))
            {
              gphi *phi = gpi.phi ();
              add_phi_arg (phi, gimple_phi_arg_def (phi, dest_idx),
                           ep, UNKNOWN_LOCATION);
            }
        }
      gsi = gsi_last_bb (entry_bb);
    }

  switch (gimple_omp_for_kind (fd->for_stmt))
    {
    case GF_OMP_FOR_KIND_FOR:
      nthreads = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_THREADS);
      threadid = builtin_decl_explicit (BUILT_IN_OMP_GET_THREAD_NUM);
      break;
    case GF_OMP_FOR_KIND_DISTRIBUTE:
      nthreads = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_TEAMS);
      threadid = builtin_decl_explicit (BUILT_IN_OMP_GET_TEAM_NUM);
      break;
    case GF_OMP_FOR_KIND_OACC_LOOP:
      nthreads = builtin_decl_explicit (BUILT_IN_GOACC_GET_NUM_THREADS);
      threadid = builtin_decl_explicit (BUILT_IN_GOACC_GET_THREAD_NUM);
      break;
    default:
      gcc_unreachable ();
    }
  nthreads = build_call_expr (nthreads, 0);
  nthreads = fold_convert (itype, nthreads);
  nthreads = force_gimple_operand_gsi (&gsi, nthreads, true, NULL_TREE,
                                       true, GSI_SAME_STMT);
  threadid = build_call_expr (threadid, 0);
  threadid = fold_convert (itype, threadid);
  threadid = force_gimple_operand_gsi (&gsi, threadid, true, NULL_TREE,
                                       true, GSI_SAME_STMT);

  n1 = fd->loop.n1;
  n2 = fd->loop.n2;
  step = fd->loop.step;
  if (gimple_omp_for_combined_into_p (fd->for_stmt))
    {
      tree innerc = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                     OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      n1 = OMP_CLAUSE_DECL (innerc);
      innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      n2 = OMP_CLAUSE_DECL (innerc);
    }
  n1 = force_gimple_operand_gsi (&gsi, fold_convert (type, n1),
                                 true, NULL_TREE, true, GSI_SAME_STMT);
  n2 = force_gimple_operand_gsi (&gsi, fold_convert (itype, n2),
                                 true, NULL_TREE, true, GSI_SAME_STMT);
  step = force_gimple_operand_gsi (&gsi, fold_convert (itype, step),
                                   true, NULL_TREE, true, GSI_SAME_STMT);

  t = build_int_cst (itype, (fd->loop.cond_code == LT_EXPR ? -1 : 1));
  t = fold_build2 (PLUS_EXPR, itype, step, t);
  t = fold_build2 (PLUS_EXPR, itype, t, n2);
  t = fold_build2 (MINUS_EXPR, itype, t, fold_convert (itype, n1));
  if (TYPE_UNSIGNED (itype) && fd->loop.cond_code == GT_EXPR)
    t = fold_build2 (TRUNC_DIV_EXPR, itype,
                     fold_build1 (NEGATE_EXPR, itype, t),
                     fold_build1 (NEGATE_EXPR, itype, step));
  else
    t = fold_build2 (TRUNC_DIV_EXPR, itype, t, step);
  t = fold_convert (itype, t);
  n = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE, true, GSI_SAME_STMT);

  q = create_tmp_reg (itype, "q");
  t = fold_build2 (TRUNC_DIV_EXPR, itype, n, nthreads);
  t = force_gimple_operand_gsi (&gsi, t, false, NULL_TREE, true, GSI_SAME_STMT);
  gsi_insert_before (&gsi, gimple_build_assign (q, t), GSI_SAME_STMT);

  tt = create_tmp_reg (itype, "tt");
  t = fold_build2 (TRUNC_MOD_EXPR, itype, n, nthreads);
  t = force_gimple_operand_gsi (&gsi, t, false, NULL_TREE, true, GSI_SAME_STMT);
  gsi_insert_before (&gsi, gimple_build_assign (tt, t), GSI_SAME_STMT);

  t = build2 (LT_EXPR, boolean_type_node, threadid, tt);
  gcond *cond_stmt = gimple_build_cond_empty (t);
  gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);

  second_bb = split_block (entry_bb, cond_stmt)->dest;
  gsi = gsi_last_bb (second_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);

  gsi_insert_before (&gsi, gimple_build_assign (tt, build_int_cst (itype, 0)),
                     GSI_SAME_STMT);
  gassign *assign_stmt
    = gimple_build_assign (q, PLUS_EXPR, q, build_int_cst (itype, 1));
  gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);

  third_bb = split_block (second_bb, assign_stmt)->dest;
  gsi = gsi_last_bb (third_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);

  t = build2 (MULT_EXPR, itype, q, threadid);
  t = build2 (PLUS_EXPR, itype, t, tt);
  s0 = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE, true, GSI_SAME_STMT);

  t = fold_build2 (PLUS_EXPR, itype, s0, q);
  e0 = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE, true, GSI_SAME_STMT);

  t = build2 (GE_EXPR, boolean_type_node, s0, e0);
  gsi_insert_before (&gsi, gimple_build_cond_empty (t), GSI_SAME_STMT);

  /* Remove the GIMPLE_OMP_FOR statement.  */
  gsi_remove (&gsi, true);

  /* Setup code for sequential iteration goes in SEQ_START_BB.  */
  gsi = gsi_start_bb (seq_start_bb);

  tree startvar = fd->loop.v;
  tree endvar = NULL_TREE;

  if (gimple_omp_for_combined_p (fd->for_stmt))
    {
      tree clauses = gimple_code (inner_stmt) == GIMPLE_OMP_PARALLEL
                     ? gimple_omp_parallel_clauses (inner_stmt)
                     : gimple_omp_for_clauses (inner_stmt);
      tree innerc = find_omp_clause (clauses, OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      startvar = OMP_CLAUSE_DECL (innerc);
      innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      endvar = OMP_CLAUSE_DECL (innerc);
    }
  t = fold_convert (itype, s0);
  t = fold_build2 (MULT_EXPR, itype, t, step);
  if (POINTER_TYPE_P (type))
    t = fold_build_pointer_plus (n1, t);
  else
    t = fold_build2 (PLUS_EXPR, type, t, n1);
  t = fold_convert (TREE_TYPE (startvar), t);
  t = force_gimple_operand_gsi (&gsi, t,
                                DECL_P (startvar)
                                && TREE_ADDRESSABLE (startvar),
                                NULL_TREE, false, GSI_CONTINUE_LINKING);
  assign_stmt = gimple_build_assign (startvar, t);
  gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);

  t = fold_convert (itype, e0);
  t = fold_build2 (MULT_EXPR, itype, t, step);
  if (POINTER_TYPE_P (type))
    t = fold_build_pointer_plus (n1, t);
  else
    t = fold_build2 (PLUS_EXPR, type, t, n1);
  t = fold_convert (TREE_TYPE (startvar), t);
  e = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                false, GSI_CONTINUE_LINKING);
  if (endvar)
    {
      assign_stmt = gimple_build_assign (endvar, e);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
      if (useless_type_conversion_p (TREE_TYPE (fd->loop.v), TREE_TYPE (e)))
        assign_stmt = gimple_build_assign (fd->loop.v, e);
      else
        assign_stmt = gimple_build_assign (fd->loop.v, NOP_EXPR, e);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
    }
  if (fd->collapse > 1)
    expand_omp_for_init_vars (fd, &gsi, counts, inner_stmt, startvar);

  if (!broken_loop)
    {
      /* The code controlling the sequential loop replaces the
         GIMPLE_OMP_CONTINUE.  */
      gsi = gsi_last_bb (cont_bb);
      gomp_continue *cont_stmt = as_a <gomp_continue *> (gsi_stmt (gsi));
      gcc_assert (gimple_code (cont_stmt) == GIMPLE_OMP_CONTINUE);
      vmain = gimple_omp_continue_control_use (cont_stmt);
      vback = gimple_omp_continue_control_def (cont_stmt);

      if (!gimple_omp_for_combined_p (fd->for_stmt))
        {
          if (POINTER_TYPE_P (type))
            t = fold_build_pointer_plus (vmain, step);
          else
            t = fold_build2 (PLUS_EXPR, type, vmain, step);
          t = force_gimple_operand_gsi (&gsi, t,
                                        DECL_P (vback)
                                        && TREE_ADDRESSABLE (vback),
                                        NULL_TREE, true, GSI_SAME_STMT);
          assign_stmt = gimple_build_assign (vback, t);
          gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);

          t = build2 (fd->loop.cond_code, boolean_type_node,
                      DECL_P (vback) && TREE_ADDRESSABLE (vback)
                      ? t : vback, e);
          gsi_insert_before (&gsi, gimple_build_cond_empty (t), GSI_SAME_STMT);
        }

      /* Remove the GIMPLE_OMP_CONTINUE statement.  */
      gsi_remove (&gsi, true);

      if (fd->collapse > 1 && !gimple_omp_for_combined_p (fd->for_stmt))
        collapse_bb = extract_omp_for_update_vars (fd, cont_bb, body_bb);
    }

  /* Replace the GIMPLE_OMP_RETURN with a barrier, or nothing.  */
  gsi = gsi_last_bb (exit_bb);
  if (!gimple_omp_return_nowait_p (gsi_stmt (gsi)))
    {
      t = gimple_omp_return_lhs (gsi_stmt (gsi));
      if (gimple_omp_for_kind (fd->for_stmt) == GF_OMP_FOR_KIND_OACC_LOOP)
        gcc_checking_assert (t == NULL_TREE);
      else
        gsi_insert_after (&gsi, build_omp_barrier (t), GSI_SAME_STMT);
    }
  gsi_remove (&gsi, true);

  /* Connect all the blocks.  */
  ep = make_edge (entry_bb, third_bb, EDGE_FALSE_VALUE);
  ep->probability = REG_BR_PROB_BASE / 4 * 3;
  ep = find_edge (entry_bb, second_bb);
  ep->flags = EDGE_TRUE_VALUE;
  ep->probability = REG_BR_PROB_BASE / 4;
  find_edge (third_bb, seq_start_bb)->flags = EDGE_FALSE_VALUE;
  find_edge (third_bb, fin_bb)->flags = EDGE_TRUE_VALUE;

  if (!broken_loop)
    {
      ep = find_edge (cont_bb, body_bb);
      if (ep == NULL)
        {
          ep = BRANCH_EDGE (cont_bb);
          gcc_assert (single_succ (ep->dest) == body_bb);
        }
      if (gimple_omp_for_combined_p (fd->for_stmt))
        {
          remove_edge (ep);
          ep = NULL;
        }
      else if (fd->collapse > 1)
        {
          remove_edge (ep);
          ep = make_edge (cont_bb, collapse_bb, EDGE_TRUE_VALUE);
        }
      else
        ep->flags = EDGE_TRUE_VALUE;
      find_edge (cont_bb, fin_bb)->flags
        = ep ? EDGE_FALSE_VALUE : EDGE_FALLTHRU;
    }

  set_immediate_dominator (CDI_DOMINATORS, second_bb, entry_bb);
  set_immediate_dominator (CDI_DOMINATORS, third_bb, entry_bb);
  set_immediate_dominator (CDI_DOMINATORS, seq_start_bb, third_bb);

  set_immediate_dominator (CDI_DOMINATORS, body_bb,
                           recompute_dominator (CDI_DOMINATORS, body_bb));
  set_immediate_dominator (CDI_DOMINATORS, fin_bb,
                           recompute_dominator (CDI_DOMINATORS, fin_bb));

  struct loop *loop = body_bb->loop_father;
  if (loop != entry_bb->loop_father)
    {
      gcc_assert (loop->header == body_bb);
      gcc_assert (broken_loop
                  || loop->latch == region->cont
                  || single_pred (loop->latch) == region->cont);
      return;
    }

  if (!broken_loop && !gimple_omp_for_combined_p (fd->for_stmt))
    {
      loop = alloc_loop ();
      loop->header = body_bb;
      if (collapse_bb == NULL)
        loop->latch = cont_bb;
      add_loop (loop, body_bb->loop_father);
    }
}

/* Return phi in E->DEST with ARG on edge E.  */

static gphi *
find_phi_with_arg_on_edge (tree arg, edge e)
{
  basic_block bb = e->dest;

  for (gphi_iterator gpi = gsi_start_phis (bb);
       !gsi_end_p (gpi);
       gsi_next (&gpi))
    {
      gphi *phi = gpi.phi ();
      if (PHI_ARG_DEF_FROM_EDGE (phi, e) == arg)
        return phi;
    }

  return NULL;
}

/* A subroutine of expand_omp_for.  Generate code for a parallel
   loop with static schedule and a specified chunk size.  Given
   parameters:

        for (V = N1; V cond N2; V += STEP) BODY;

   where COND is "<" or ">", we generate pseudocode

        if ((__typeof (V)) -1 > 0 && N2 cond N1) goto L2;
        if (cond is <)
          adj = STEP - 1;
        else
          adj = STEP + 1;
        if ((__typeof (V)) -1 > 0 && cond is >)
          n = -(adj + N2 - N1) / -STEP;
        else
          n = (adj + N2 - N1) / STEP;
        trip = 0;
        V = threadid * CHUNK * STEP + N1;  -- this extra definition of V is
                                              here so that V is defined
                                              if the loop is not entered
    L0:
        s0 = (trip * nthreads + threadid) * CHUNK;
        e0 = min(s0 + CHUNK, n);
        if (s0 < n) goto L1; else goto L4;
    L1:
        V = s0 * STEP + N1;
        e = e0 * STEP + N1;
    L2:
        BODY;
        V += STEP;
        if (V cond e) goto L2; else goto L3;
    L3:
        trip += 1;
        goto L0;
    L4:
*/

static void
expand_omp_for_static_chunk (struct omp_region *region,
                             struct omp_for_data *fd, gimple inner_stmt)
{
  tree n, s0, e0, e, t;
  tree trip_var, trip_init, trip_main, trip_back, nthreads, threadid;
  tree type, itype, vmain, vback, vextra;
  basic_block entry_bb, exit_bb, body_bb, seq_start_bb, iter_part_bb;
  basic_block trip_update_bb = NULL, cont_bb, collapse_bb = NULL, fin_bb;
  gimple_stmt_iterator gsi;
  edge se;
  bool broken_loop = region->cont == NULL;
  tree *counts = NULL;
  tree n1, n2, step;

  gcc_checking_assert ((gimple_omp_for_kind (fd->for_stmt)
                        != GF_OMP_FOR_KIND_OACC_LOOP)
                       || !inner_stmt);

  itype = type = TREE_TYPE (fd->loop.v);
  if (POINTER_TYPE_P (type))
    itype = signed_type_for (type);

  entry_bb = region->entry;
  se = split_block (entry_bb, last_stmt (entry_bb));
  entry_bb = se->src;
  iter_part_bb = se->dest;
  cont_bb = region->cont;
  gcc_assert (EDGE_COUNT (iter_part_bb->succs) == 2);
  fin_bb = BRANCH_EDGE (iter_part_bb)->dest;
  gcc_assert (broken_loop
              || fin_bb == FALLTHRU_EDGE (cont_bb)->dest);
  seq_start_bb = split_edge (FALLTHRU_EDGE (iter_part_bb));
  body_bb = single_succ (seq_start_bb);
  if (!broken_loop)
    {
      gcc_assert (BRANCH_EDGE (cont_bb)->dest == body_bb
                  || single_succ (BRANCH_EDGE (cont_bb)->dest) == body_bb);
      gcc_assert (EDGE_COUNT (cont_bb->succs) == 2);
      trip_update_bb = split_edge (FALLTHRU_EDGE (cont_bb));
    }
  exit_bb = region->exit;

  /* Trip and adjustment setup goes in ENTRY_BB.  */
  gsi = gsi_last_bb (entry_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);

  if (fd->collapse > 1)
    {
      int first_zero_iter = -1;
      basic_block l2_dom_bb = NULL;

      counts = XALLOCAVEC (tree, fd->collapse);
      expand_omp_for_init_counts (fd, &gsi, entry_bb, counts,
                                  fin_bb, first_zero_iter,
                                  l2_dom_bb);
      t = NULL_TREE;
    }
  else if (gimple_omp_for_combined_into_p (fd->for_stmt))
    t = integer_one_node;
  else
    t = fold_binary (fd->loop.cond_code, boolean_type_node,
                     fold_convert (type, fd->loop.n1),
                     fold_convert (type, fd->loop.n2));
  if (fd->collapse == 1
      && TYPE_UNSIGNED (type)
      && (t == NULL_TREE || !integer_onep (t)))
    {
      n1 = fold_convert (type, unshare_expr (fd->loop.n1));
      n1 = force_gimple_operand_gsi (&gsi, n1, true, NULL_TREE,
                                     true, GSI_SAME_STMT);
      n2 = fold_convert (type, unshare_expr (fd->loop.n2));
      n2 = force_gimple_operand_gsi (&gsi, n2, true, NULL_TREE,
                                     true, GSI_SAME_STMT);
      gcond *cond_stmt = gimple_build_cond (fd->loop.cond_code, n1, n2,
                                                 NULL_TREE, NULL_TREE);
      gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
      if (walk_tree (gimple_cond_lhs_ptr (cond_stmt),
                     expand_omp_regimplify_p, NULL, NULL)
          || walk_tree (gimple_cond_rhs_ptr (cond_stmt),
                        expand_omp_regimplify_p, NULL, NULL))
        {
          gsi = gsi_for_stmt (cond_stmt);
          gimple_regimplify_operands (cond_stmt, &gsi);
        }
      se = split_block (entry_bb, cond_stmt);
      se->flags = EDGE_TRUE_VALUE;
      entry_bb = se->dest;
      se->probability = REG_BR_PROB_BASE - (REG_BR_PROB_BASE / 2000 - 1);
      se = make_edge (se->src, fin_bb, EDGE_FALSE_VALUE);
      se->probability = REG_BR_PROB_BASE / 2000 - 1;
      if (gimple_in_ssa_p (cfun))
        {
          int dest_idx = find_edge (iter_part_bb, fin_bb)->dest_idx;
          for (gphi_iterator gpi = gsi_start_phis (fin_bb);
               !gsi_end_p (gpi); gsi_next (&gpi))
            {
              gphi *phi = gpi.phi ();
              add_phi_arg (phi, gimple_phi_arg_def (phi, dest_idx),
                           se, UNKNOWN_LOCATION);
            }
        }
      gsi = gsi_last_bb (entry_bb);
    }

  switch (gimple_omp_for_kind (fd->for_stmt))
    {
    case GF_OMP_FOR_KIND_FOR:
      nthreads = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_THREADS);
      threadid = builtin_decl_explicit (BUILT_IN_OMP_GET_THREAD_NUM);
      break;
    case GF_OMP_FOR_KIND_DISTRIBUTE:
      nthreads = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_TEAMS);
      threadid = builtin_decl_explicit (BUILT_IN_OMP_GET_TEAM_NUM);
      break;
    case GF_OMP_FOR_KIND_OACC_LOOP:
      nthreads = builtin_decl_explicit (BUILT_IN_GOACC_GET_NUM_THREADS);
      threadid = builtin_decl_explicit (BUILT_IN_GOACC_GET_THREAD_NUM);
      break;
    default:
      gcc_unreachable ();
    }
  nthreads = build_call_expr (nthreads, 0);
  nthreads = fold_convert (itype, nthreads);
  nthreads = force_gimple_operand_gsi (&gsi, nthreads, true, NULL_TREE,
                                       true, GSI_SAME_STMT);
  threadid = build_call_expr (threadid, 0);
  threadid = fold_convert (itype, threadid);
  threadid = force_gimple_operand_gsi (&gsi, threadid, true, NULL_TREE,
                                       true, GSI_SAME_STMT);

  n1 = fd->loop.n1;
  n2 = fd->loop.n2;
  step = fd->loop.step;
  if (gimple_omp_for_combined_into_p (fd->for_stmt))
    {
      tree innerc = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                     OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      n1 = OMP_CLAUSE_DECL (innerc);
      innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      n2 = OMP_CLAUSE_DECL (innerc);
    }
  n1 = force_gimple_operand_gsi (&gsi, fold_convert (type, n1),
                                 true, NULL_TREE, true, GSI_SAME_STMT);
  n2 = force_gimple_operand_gsi (&gsi, fold_convert (itype, n2),
                                 true, NULL_TREE, true, GSI_SAME_STMT);
  step = force_gimple_operand_gsi (&gsi, fold_convert (itype, step),
                                   true, NULL_TREE, true, GSI_SAME_STMT);
  fd->chunk_size
    = force_gimple_operand_gsi (&gsi, fold_convert (itype, fd->chunk_size),
                                true, NULL_TREE, true, GSI_SAME_STMT);

  t = build_int_cst (itype, (fd->loop.cond_code == LT_EXPR ? -1 : 1));
  t = fold_build2 (PLUS_EXPR, itype, step, t);
  t = fold_build2 (PLUS_EXPR, itype, t, n2);
  t = fold_build2 (MINUS_EXPR, itype, t, fold_convert (itype, n1));
  if (TYPE_UNSIGNED (itype) && fd->loop.cond_code == GT_EXPR)
    t = fold_build2 (TRUNC_DIV_EXPR, itype,
                     fold_build1 (NEGATE_EXPR, itype, t),
                     fold_build1 (NEGATE_EXPR, itype, step));
  else
    t = fold_build2 (TRUNC_DIV_EXPR, itype, t, step);
  t = fold_convert (itype, t);
  n = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                true, GSI_SAME_STMT);

  trip_var = create_tmp_reg (itype, ".trip");
  if (gimple_in_ssa_p (cfun))
    {
      trip_init = make_ssa_name (trip_var);
      trip_main = make_ssa_name (trip_var);
      trip_back = make_ssa_name (trip_var);
    }
  else
    {
      trip_init = trip_var;
      trip_main = trip_var;
      trip_back = trip_var;
    }

  gassign *assign_stmt
    = gimple_build_assign (trip_init, build_int_cst (itype, 0));
  gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);

  t = fold_build2 (MULT_EXPR, itype, threadid, fd->chunk_size);
  t = fold_build2 (MULT_EXPR, itype, t, step);
  if (POINTER_TYPE_P (type))
    t = fold_build_pointer_plus (n1, t);
  else
    t = fold_build2 (PLUS_EXPR, type, t, n1);
  vextra = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                     true, GSI_SAME_STMT);

  /* Remove the GIMPLE_OMP_FOR.  */
  gsi_remove (&gsi, true);

  /* Iteration space partitioning goes in ITER_PART_BB.  */
  gsi = gsi_last_bb (iter_part_bb);

  t = fold_build2 (MULT_EXPR, itype, trip_main, nthreads);
  t = fold_build2 (PLUS_EXPR, itype, t, threadid);
  t = fold_build2 (MULT_EXPR, itype, t, fd->chunk_size);
  s0 = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                 false, GSI_CONTINUE_LINKING);

  t = fold_build2 (PLUS_EXPR, itype, s0, fd->chunk_size);
  t = fold_build2 (MIN_EXPR, itype, t, n);
  e0 = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                 false, GSI_CONTINUE_LINKING);

  t = build2 (LT_EXPR, boolean_type_node, s0, n);
  gsi_insert_after (&gsi, gimple_build_cond_empty (t), GSI_CONTINUE_LINKING);

  /* Setup code for sequential iteration goes in SEQ_START_BB.  */
  gsi = gsi_start_bb (seq_start_bb);

  tree startvar = fd->loop.v;
  tree endvar = NULL_TREE;

  if (gimple_omp_for_combined_p (fd->for_stmt))
    {
      tree clauses = gimple_code (inner_stmt) == GIMPLE_OMP_PARALLEL
                     ? gimple_omp_parallel_clauses (inner_stmt)
                     : gimple_omp_for_clauses (inner_stmt);
      tree innerc = find_omp_clause (clauses, OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      startvar = OMP_CLAUSE_DECL (innerc);
      innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      endvar = OMP_CLAUSE_DECL (innerc);
    }

  t = fold_convert (itype, s0);
  t = fold_build2 (MULT_EXPR, itype, t, step);
  if (POINTER_TYPE_P (type))
    t = fold_build_pointer_plus (n1, t);
  else
    t = fold_build2 (PLUS_EXPR, type, t, n1);
  t = fold_convert (TREE_TYPE (startvar), t);
  t = force_gimple_operand_gsi (&gsi, t,
                                DECL_P (startvar)
                                && TREE_ADDRESSABLE (startvar),
                                NULL_TREE, false, GSI_CONTINUE_LINKING);
  assign_stmt = gimple_build_assign (startvar, t);
  gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);

  t = fold_convert (itype, e0);
  t = fold_build2 (MULT_EXPR, itype, t, step);
  if (POINTER_TYPE_P (type))
    t = fold_build_pointer_plus (n1, t);
  else
    t = fold_build2 (PLUS_EXPR, type, t, n1);
  t = fold_convert (TREE_TYPE (startvar), t);
  e = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                false, GSI_CONTINUE_LINKING);
  if (endvar)
    {
      assign_stmt = gimple_build_assign (endvar, e);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
      if (useless_type_conversion_p (TREE_TYPE (fd->loop.v), TREE_TYPE (e)))
        assign_stmt = gimple_build_assign (fd->loop.v, e);
      else
        assign_stmt = gimple_build_assign (fd->loop.v, NOP_EXPR, e);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
    }
  if (fd->collapse > 1)
    expand_omp_for_init_vars (fd, &gsi, counts, inner_stmt, startvar);

  if (!broken_loop)
    {
      /* The code controlling the sequential loop goes in CONT_BB,
         replacing the GIMPLE_OMP_CONTINUE.  */
      gsi = gsi_last_bb (cont_bb);
      gomp_continue *cont_stmt = as_a <gomp_continue *> (gsi_stmt (gsi));
      vmain = gimple_omp_continue_control_use (cont_stmt);
      vback = gimple_omp_continue_control_def (cont_stmt);

      if (!gimple_omp_for_combined_p (fd->for_stmt))
        {
          if (POINTER_TYPE_P (type))
            t = fold_build_pointer_plus (vmain, step);
          else
            t = fold_build2 (PLUS_EXPR, type, vmain, step);
          if (DECL_P (vback) && TREE_ADDRESSABLE (vback))
            t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                          true, GSI_SAME_STMT);
          assign_stmt = gimple_build_assign (vback, t);
          gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);

          if (tree_int_cst_equal (fd->chunk_size, integer_one_node))
            t = build2 (EQ_EXPR, boolean_type_node,
                        build_int_cst (itype, 0),
                        build_int_cst (itype, 1));
          else
            t = build2 (fd->loop.cond_code, boolean_type_node,
                        DECL_P (vback) && TREE_ADDRESSABLE (vback)
                        ? t : vback, e);
          gsi_insert_before (&gsi, gimple_build_cond_empty (t), GSI_SAME_STMT);
        }

      /* Remove GIMPLE_OMP_CONTINUE.  */
      gsi_remove (&gsi, true);

      if (fd->collapse > 1 && !gimple_omp_for_combined_p (fd->for_stmt))
        collapse_bb = extract_omp_for_update_vars (fd, cont_bb, body_bb);

      /* Trip update code goes into TRIP_UPDATE_BB.  */
      gsi = gsi_start_bb (trip_update_bb);

      t = build_int_cst (itype, 1);
      t = build2 (PLUS_EXPR, itype, trip_main, t);
      assign_stmt = gimple_build_assign (trip_back, t);
      gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
    }

  /* Replace the GIMPLE_OMP_RETURN with a barrier, or nothing.  */
  gsi = gsi_last_bb (exit_bb);
  if (!gimple_omp_return_nowait_p (gsi_stmt (gsi)))
    {
      t = gimple_omp_return_lhs (gsi_stmt (gsi));
      if (gimple_omp_for_kind (fd->for_stmt) == GF_OMP_FOR_KIND_OACC_LOOP)
        gcc_checking_assert (t == NULL_TREE);
      else
        gsi_insert_after (&gsi, build_omp_barrier (t), GSI_SAME_STMT);
    }
  gsi_remove (&gsi, true);

  /* Connect the new blocks.  */
  find_edge (iter_part_bb, seq_start_bb)->flags = EDGE_TRUE_VALUE;
  find_edge (iter_part_bb, fin_bb)->flags = EDGE_FALSE_VALUE;

  if (!broken_loop)
    {
      se = find_edge (cont_bb, body_bb);
      if (se == NULL)
        {
          se = BRANCH_EDGE (cont_bb);
          gcc_assert (single_succ (se->dest) == body_bb);
        }
      if (gimple_omp_for_combined_p (fd->for_stmt))
        {
          remove_edge (se);
          se = NULL;
        }
      else if (fd->collapse > 1)
        {
          remove_edge (se);
          se = make_edge (cont_bb, collapse_bb, EDGE_TRUE_VALUE);
        }
      else
        se->flags = EDGE_TRUE_VALUE;
      find_edge (cont_bb, trip_update_bb)->flags
        = se ? EDGE_FALSE_VALUE : EDGE_FALLTHRU;

      redirect_edge_and_branch (single_succ_edge (trip_update_bb), iter_part_bb);
    }

  if (gimple_in_ssa_p (cfun))
    {
      gphi_iterator psi;
      gphi *phi;
      edge re, ene;
      edge_var_map *vm;
      size_t i;

      gcc_assert (fd->collapse == 1 && !broken_loop);

      /* When we redirect the edge from trip_update_bb to iter_part_bb, we
         remove arguments of the phi nodes in fin_bb.  We need to create
         appropriate phi nodes in iter_part_bb instead.  */
      se = find_edge (iter_part_bb, fin_bb);
      re = single_succ_edge (trip_update_bb);
      vec<edge_var_map> *head = redirect_edge_var_map_vector (re);
      ene = single_succ_edge (entry_bb);

      psi = gsi_start_phis (fin_bb);
      for (i = 0; !gsi_end_p (psi) && head->iterate (i, &vm);
           gsi_next (&psi), ++i)
        {
          gphi *nphi;
          source_location locus;

          phi = psi.phi ();
          t = gimple_phi_result (phi);
          gcc_assert (t == redirect_edge_var_map_result (vm));

          if (!single_pred_p (fin_bb))
            t = copy_ssa_name (t, phi);

          nphi = create_phi_node (t, iter_part_bb);

          t = PHI_ARG_DEF_FROM_EDGE (phi, se);
          locus = gimple_phi_arg_location_from_edge (phi, se);

          /* A special case -- fd->loop.v is not yet computed in
             iter_part_bb, we need to use vextra instead.  */
          if (t == fd->loop.v)
            t = vextra;
          add_phi_arg (nphi, t, ene, locus);
          locus = redirect_edge_var_map_location (vm);
          tree back_arg = redirect_edge_var_map_def (vm);
          add_phi_arg (nphi, back_arg, re, locus);
          edge ce = find_edge (cont_bb, body_bb);
          if (ce == NULL)
            {
              ce = BRANCH_EDGE (cont_bb);
              gcc_assert (single_succ (ce->dest) == body_bb);
              ce = single_succ_edge (ce->dest);
            }
          gphi *inner_loop_phi = find_phi_with_arg_on_edge (back_arg, ce);
          gcc_assert (inner_loop_phi != NULL);
          add_phi_arg (inner_loop_phi, gimple_phi_result (nphi),
                       find_edge (seq_start_bb, body_bb), locus);

          if (!single_pred_p (fin_bb))
            add_phi_arg (phi, gimple_phi_result (nphi), se, locus);
        }
      gcc_assert (gsi_end_p (psi) && (head == NULL || i == head->length ()));
      redirect_edge_var_map_clear (re);
      if (single_pred_p (fin_bb))
        while (1)
          {
            psi = gsi_start_phis (fin_bb);
            if (gsi_end_p (psi))
              break;
            remove_phi_node (&psi, false);
          }

      /* Make phi node for trip.  */
      phi = create_phi_node (trip_main, iter_part_bb);
      add_phi_arg (phi, trip_back, single_succ_edge (trip_update_bb),
                   UNKNOWN_LOCATION);
      add_phi_arg (phi, trip_init, single_succ_edge (entry_bb),
                   UNKNOWN_LOCATION);
    }

  if (!broken_loop)
    set_immediate_dominator (CDI_DOMINATORS, trip_update_bb, cont_bb);
  set_immediate_dominator (CDI_DOMINATORS, iter_part_bb,
                           recompute_dominator (CDI_DOMINATORS, iter_part_bb));
  set_immediate_dominator (CDI_DOMINATORS, fin_bb,
                           recompute_dominator (CDI_DOMINATORS, fin_bb));
  set_immediate_dominator (CDI_DOMINATORS, seq_start_bb,
                           recompute_dominator (CDI_DOMINATORS, seq_start_bb));
  set_immediate_dominator (CDI_DOMINATORS, body_bb,
                           recompute_dominator (CDI_DOMINATORS, body_bb));

  if (!broken_loop)
    {
      struct loop *loop = body_bb->loop_father;
      struct loop *trip_loop = alloc_loop ();
      trip_loop->header = iter_part_bb;
      trip_loop->latch = trip_update_bb;
      add_loop (trip_loop, iter_part_bb->loop_father);

      if (loop != entry_bb->loop_father)
        {
          gcc_assert (loop->header == body_bb);
          gcc_assert (loop->latch == region->cont
                      || single_pred (loop->latch) == region->cont);
          trip_loop->inner = loop;
          return;
        }

      if (!gimple_omp_for_combined_p (fd->for_stmt))
        {
          loop = alloc_loop ();
          loop->header = body_bb;
          if (collapse_bb == NULL)
            loop->latch = cont_bb;
          add_loop (loop, trip_loop);
        }
    }
}

/* A subroutine of expand_omp_for.  Generate code for _Cilk_for loop.
   Given parameters:
   for (V = N1; V cond N2; V += STEP) BODY;

   where COND is "<" or ">" or "!=", we generate pseudocode

   for (ind_var = low; ind_var < high; ind_var++)
     {
       V = n1 + (ind_var * STEP)

       <BODY>
     }

   In the above pseudocode, low and high are function parameters of the
   child function.  In the function below, we are inserting a temp.
   variable that will be making a call to two OMP functions that will not be
   found in the body of _Cilk_for (since OMP_FOR cannot be mixed
   with _Cilk_for).  These functions are replaced with low and high
   by the function that handles taskreg.  */


static void
expand_cilk_for (struct omp_region *region, struct omp_for_data *fd)
{
  bool broken_loop = region->cont == NULL;
  basic_block entry_bb = region->entry;
  basic_block cont_bb = region->cont;

  gcc_assert (EDGE_COUNT (entry_bb->succs) == 2);
  gcc_assert (broken_loop
              || BRANCH_EDGE (entry_bb)->dest == FALLTHRU_EDGE (cont_bb)->dest);
  basic_block l0_bb = FALLTHRU_EDGE (entry_bb)->dest;
  basic_block l1_bb, l2_bb;

  if (!broken_loop)
    {
      gcc_assert (BRANCH_EDGE (cont_bb)->dest == l0_bb);
      gcc_assert (EDGE_COUNT (cont_bb->succs) == 2);
      l1_bb = split_block (cont_bb, last_stmt (cont_bb))->dest;
      l2_bb = BRANCH_EDGE (entry_bb)->dest;
    }
  else
    {
      BRANCH_EDGE (entry_bb)->flags &= ~EDGE_ABNORMAL;
      l1_bb = split_edge (BRANCH_EDGE (entry_bb));
      l2_bb = single_succ (l1_bb);
    }
  basic_block exit_bb = region->exit;
  basic_block l2_dom_bb = NULL;

  gimple_stmt_iterator gsi = gsi_last_bb (entry_bb);

  /* Below statements until the "tree high_val = ..." are pseudo statements
     used to pass information to be used by expand_omp_taskreg.
     low_val and high_val will be replaced by the __low and __high
     parameter from the child function.

     The call_exprs part is a place-holder, it is mainly used
     to distinctly identify to the top-level part that this is
     where we should put low and high (reasoning given in header
     comment).  */

  tree child_fndecl
    = gimple_omp_parallel_child_fn (
        as_a <gomp_parallel *> (last_stmt (region->outer->entry)));
  tree t, low_val = NULL_TREE, high_val = NULL_TREE;
  for (t = DECL_ARGUMENTS (child_fndecl); t; t = TREE_CHAIN (t))
    {
      if (!strcmp (IDENTIFIER_POINTER (DECL_NAME (t)), "__high"))
        high_val = t;
      else if (!strcmp (IDENTIFIER_POINTER (DECL_NAME (t)), "__low"))
        low_val = t;
    }
  gcc_assert (low_val && high_val);

  tree type = TREE_TYPE (low_val);
  tree ind_var = create_tmp_reg (type, "__cilk_ind_var");
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);

  /* Not needed in SSA form right now.  */
  gcc_assert (!gimple_in_ssa_p (cfun));
  if (l2_dom_bb == NULL)
    l2_dom_bb = l1_bb;

  tree n1 = low_val;
  tree n2 = high_val;

  gimple stmt = gimple_build_assign (ind_var, n1);

  /* Replace the GIMPLE_OMP_FOR statement.  */
  gsi_replace (&gsi, stmt, true);

  if (!broken_loop)
    {
      /* Code to control the increment goes in the CONT_BB.  */
      gsi = gsi_last_bb (cont_bb);
      stmt = gsi_stmt (gsi);
      gcc_assert (gimple_code (stmt) == GIMPLE_OMP_CONTINUE);
      stmt = gimple_build_assign (ind_var, PLUS_EXPR, ind_var,
                                  build_one_cst (type));

      /* Replace GIMPLE_OMP_CONTINUE.  */
      gsi_replace (&gsi, stmt, true);
    }

  /* Emit the condition in L1_BB.  */
  gsi = gsi_after_labels (l1_bb);
  t = fold_build2 (MULT_EXPR, TREE_TYPE (fd->loop.step),
                   fold_convert (TREE_TYPE (fd->loop.step), ind_var),
                   fd->loop.step);
  if (POINTER_TYPE_P (TREE_TYPE (fd->loop.n1)))
    t = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (fd->loop.n1),
                     fd->loop.n1, fold_convert (sizetype, t));
  else
    t = fold_build2 (PLUS_EXPR, TREE_TYPE (fd->loop.n1),
                     fd->loop.n1, fold_convert (TREE_TYPE (fd->loop.n1), t));
  t = fold_convert (TREE_TYPE (fd->loop.v), t);
  expand_omp_build_assign (&gsi, fd->loop.v, t);

  /* The condition is always '<' since the runtime will fill in the low
     and high values.  */
  stmt = gimple_build_cond (LT_EXPR, ind_var, n2, NULL_TREE, NULL_TREE);
  gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);

  /* Remove GIMPLE_OMP_RETURN.  */
  gsi = gsi_last_bb (exit_bb);
  gsi_remove (&gsi, true);

  /* Connect the new blocks.  */
  remove_edge (FALLTHRU_EDGE (entry_bb));

  edge e, ne;
  if (!broken_loop)
    {
      remove_edge (BRANCH_EDGE (entry_bb));
      make_edge (entry_bb, l1_bb, EDGE_FALLTHRU);

      e = BRANCH_EDGE (l1_bb);
      ne = FALLTHRU_EDGE (l1_bb);
      e->flags = EDGE_TRUE_VALUE;
    }
  else
    {
      single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;

      ne = single_succ_edge (l1_bb);
      e = make_edge (l1_bb, l0_bb, EDGE_TRUE_VALUE);

    }
  ne->flags = EDGE_FALSE_VALUE;
  e->probability = REG_BR_PROB_BASE * 7 / 8;
  ne->probability = REG_BR_PROB_BASE / 8;

  set_immediate_dominator (CDI_DOMINATORS, l1_bb, entry_bb);
  set_immediate_dominator (CDI_DOMINATORS, l2_bb, l2_dom_bb);
  set_immediate_dominator (CDI_DOMINATORS, l0_bb, l1_bb);

  if (!broken_loop)
    {
      struct loop *loop = alloc_loop ();
      loop->header = l1_bb;
      loop->latch = cont_bb;
      add_loop (loop, l1_bb->loop_father);
      loop->safelen = INT_MAX;
    }

  /* Pick the correct library function based on the precision of the
     induction variable type.  */
  tree lib_fun = NULL_TREE;
  if (TYPE_PRECISION (type) == 32)
    lib_fun = cilk_for_32_fndecl;
  else if (TYPE_PRECISION (type) == 64)
    lib_fun = cilk_for_64_fndecl;
  else
    gcc_unreachable ();

  gcc_assert (fd->sched_kind == OMP_CLAUSE_SCHEDULE_CILKFOR);

  /* WS_ARGS contains the library function flavor to call:
     __libcilkrts_cilk_for_64 or __libcilkrts_cilk_for_32), and the
     user-defined grain value.  If the user does not define one, then zero
     is passed in by the parser.  */
  vec_alloc (region->ws_args, 2);
  region->ws_args->quick_push (lib_fun);
  region->ws_args->quick_push (fd->chunk_size);
}

/* A subroutine of expand_omp_for.  Generate code for a simd non-worksharing
   loop.  Given parameters:

        for (V = N1; V cond N2; V += STEP) BODY;

   where COND is "<" or ">", we generate pseudocode

        V = N1;
        goto L1;
    L0:
        BODY;
        V += STEP;
    L1:
        if (V cond N2) goto L0; else goto L2;
    L2:

    For collapsed loops, given parameters:
      collapse(3)
      for (V1 = N11; V1 cond1 N12; V1 += STEP1)
        for (V2 = N21; V2 cond2 N22; V2 += STEP2)
          for (V3 = N31; V3 cond3 N32; V3 += STEP3)
            BODY;

    we generate pseudocode

        if (cond3 is <)
          adj = STEP3 - 1;
        else
          adj = STEP3 + 1;
        count3 = (adj + N32 - N31) / STEP3;
        if (cond2 is <)
          adj = STEP2 - 1;
        else
          adj = STEP2 + 1;
        count2 = (adj + N22 - N21) / STEP2;
        if (cond1 is <)
          adj = STEP1 - 1;
        else
          adj = STEP1 + 1;
        count1 = (adj + N12 - N11) / STEP1;
        count = count1 * count2 * count3;
        V = 0;
        V1 = N11;
        V2 = N21;
        V3 = N31;
        goto L1;
    L0:
        BODY;
        V += 1;
        V3 += STEP3;
        V2 += (V3 cond3 N32) ? 0 : STEP2;
        V3 = (V3 cond3 N32) ? V3 : N31;
        V1 += (V2 cond2 N22) ? 0 : STEP1;
        V2 = (V2 cond2 N22) ? V2 : N21;
    L1:
        if (V < count) goto L0; else goto L2;
    L2:

      */

static void
expand_omp_simd (struct omp_region *region, struct omp_for_data *fd)
{
  tree type, t;
  basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb, l2_bb, l2_dom_bb;
  gimple_stmt_iterator gsi;
  gimple stmt;
  gcond *cond_stmt;
  bool broken_loop = region->cont == NULL;
  edge e, ne;
  tree *counts = NULL;
  int i;
  tree safelen = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                  OMP_CLAUSE_SAFELEN);
  tree simduid = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                  OMP_CLAUSE__SIMDUID_);
  tree n1, n2;

  type = TREE_TYPE (fd->loop.v);
  entry_bb = region->entry;
  cont_bb = region->cont;
  gcc_assert (EDGE_COUNT (entry_bb->succs) == 2);
  gcc_assert (broken_loop
              || BRANCH_EDGE (entry_bb)->dest == FALLTHRU_EDGE (cont_bb)->dest);
  l0_bb = FALLTHRU_EDGE (entry_bb)->dest;
  if (!broken_loop)
    {
      gcc_assert (BRANCH_EDGE (cont_bb)->dest == l0_bb);
      gcc_assert (EDGE_COUNT (cont_bb->succs) == 2);
      l1_bb = split_block (cont_bb, last_stmt (cont_bb))->dest;
      l2_bb = BRANCH_EDGE (entry_bb)->dest;
    }
  else
    {
      BRANCH_EDGE (entry_bb)->flags &= ~EDGE_ABNORMAL;
      l1_bb = split_edge (BRANCH_EDGE (entry_bb));
      l2_bb = single_succ (l1_bb);
    }
  exit_bb = region->exit;
  l2_dom_bb = NULL;

  gsi = gsi_last_bb (entry_bb);

  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_FOR);
  /* Not needed in SSA form right now.  */
  gcc_assert (!gimple_in_ssa_p (cfun));
  if (fd->collapse > 1)
    {
      int first_zero_iter = -1;
      basic_block zero_iter_bb = l2_bb;

      counts = XALLOCAVEC (tree, fd->collapse);
      expand_omp_for_init_counts (fd, &gsi, entry_bb, counts,
                                  zero_iter_bb, first_zero_iter,
                                  l2_dom_bb);
    }
  if (l2_dom_bb == NULL)
    l2_dom_bb = l1_bb;

  n1 = fd->loop.n1;
  n2 = fd->loop.n2;
  if (gimple_omp_for_combined_into_p (fd->for_stmt))
    {
      tree innerc = find_omp_clause (gimple_omp_for_clauses (fd->for_stmt),
                                     OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      n1 = OMP_CLAUSE_DECL (innerc);
      innerc = find_omp_clause (OMP_CLAUSE_CHAIN (innerc),
                                OMP_CLAUSE__LOOPTEMP_);
      gcc_assert (innerc);
      n2 = OMP_CLAUSE_DECL (innerc);
      expand_omp_build_assign (&gsi, fd->loop.v,
                               fold_convert (type, n1));
      if (fd->collapse > 1)
        {
          gsi_prev (&gsi);
          expand_omp_for_init_vars (fd, &gsi, counts, NULL, n1);
          gsi_next (&gsi);
        }
    }
  else
    {
      expand_omp_build_assign (&gsi, fd->loop.v,
                               fold_convert (type, fd->loop.n1));
      if (fd->collapse > 1)
        for (i = 0; i < fd->collapse; i++)
          {
            tree itype = TREE_TYPE (fd->loops[i].v);
            if (POINTER_TYPE_P (itype))
              itype = signed_type_for (itype);
            t = fold_convert (TREE_TYPE (fd->loops[i].v), fd->loops[i].n1);
            expand_omp_build_assign (&gsi, fd->loops[i].v, t);
          }
      }

  /* Remove the GIMPLE_OMP_FOR statement.  */
  gsi_remove (&gsi, true);

  if (!broken_loop)
    {
      /* Code to control the increment goes in the CONT_BB.  */
      gsi = gsi_last_bb (cont_bb);
      stmt = gsi_stmt (gsi);
      gcc_assert (gimple_code (stmt) == GIMPLE_OMP_CONTINUE);

      if (POINTER_TYPE_P (type))
        t = fold_build_pointer_plus (fd->loop.v, fd->loop.step);
      else
        t = fold_build2 (PLUS_EXPR, type, fd->loop.v, fd->loop.step);
      expand_omp_build_assign (&gsi, fd->loop.v, t);

      if (fd->collapse > 1)
        {
          i = fd->collapse - 1;
          if (POINTER_TYPE_P (TREE_TYPE (fd->loops[i].v)))
            {
              t = fold_convert (sizetype, fd->loops[i].step);
              t = fold_build_pointer_plus (fd->loops[i].v, t);
            }
          else
            {
              t = fold_convert (TREE_TYPE (fd->loops[i].v),
                                fd->loops[i].step);
              t = fold_build2 (PLUS_EXPR, TREE_TYPE (fd->loops[i].v),
                               fd->loops[i].v, t);
            }
          expand_omp_build_assign (&gsi, fd->loops[i].v, t);

          for (i = fd->collapse - 1; i > 0; i--)
            {
              tree itype = TREE_TYPE (fd->loops[i].v);
              tree itype2 = TREE_TYPE (fd->loops[i - 1].v);
              if (POINTER_TYPE_P (itype2))
                itype2 = signed_type_for (itype2);
              t = build3 (COND_EXPR, itype2,
                          build2 (fd->loops[i].cond_code, boolean_type_node,
                                  fd->loops[i].v,
                                  fold_convert (itype, fd->loops[i].n2)),
                          build_int_cst (itype2, 0),
                          fold_convert (itype2, fd->loops[i - 1].step));
              if (POINTER_TYPE_P (TREE_TYPE (fd->loops[i - 1].v)))
                t = fold_build_pointer_plus (fd->loops[i - 1].v, t);
              else
                t = fold_build2 (PLUS_EXPR, itype2, fd->loops[i - 1].v, t);
              expand_omp_build_assign (&gsi, fd->loops[i - 1].v, t);

              t = build3 (COND_EXPR, itype,
                          build2 (fd->loops[i].cond_code, boolean_type_node,
                                  fd->loops[i].v,
                                  fold_convert (itype, fd->loops[i].n2)),
                          fd->loops[i].v,
                          fold_convert (itype, fd->loops[i].n1));
              expand_omp_build_assign (&gsi, fd->loops[i].v, t);
            }
        }

      /* Remove GIMPLE_OMP_CONTINUE.  */
      gsi_remove (&gsi, true);
    }

  /* Emit the condition in L1_BB.  */
  gsi = gsi_start_bb (l1_bb);

  t = fold_convert (type, n2);
  t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
                                false, GSI_CONTINUE_LINKING);
  t = build2 (fd->loop.cond_code, boolean_type_node, fd->loop.v, t);
  cond_stmt = gimple_build_cond_empty (t);
  gsi_insert_after (&gsi, cond_stmt, GSI_CONTINUE_LINKING);
  if (walk_tree (gimple_cond_lhs_ptr (cond_stmt), expand_omp_regimplify_p,
                 NULL, NULL)
      || walk_tree (gimple_cond_rhs_ptr (cond_stmt), expand_omp_regimplify_p,
                    NULL, NULL))
    {
      gsi = gsi_for_stmt (cond_stmt);
      gimple_regimplify_operands (cond_stmt, &gsi);
    }

  /* Remove GIMPLE_OMP_RETURN.  */
  gsi = gsi_last_bb (exit_bb);
  gsi_remove (&gsi, true);

  /* Connect the new blocks.  */
  remove_edge (FALLTHRU_EDGE (entry_bb));

  if (!broken_loop)
    {
      remove_edge (BRANCH_EDGE (entry_bb));
      make_edge (entry_bb, l1_bb, EDGE_FALLTHRU);

      e = BRANCH_EDGE (l1_bb);
      ne = FALLTHRU_EDGE (l1_bb);
      e->flags = EDGE_TRUE_VALUE;
    }
  else
    {
      single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;

      ne = single_succ_edge (l1_bb);
      e = make_edge (l1_bb, l0_bb, EDGE_TRUE_VALUE);

    }
  ne->flags = EDGE_FALSE_VALUE;
  e->probability = REG_BR_PROB_BASE * 7 / 8;
  ne->probability = REG_BR_PROB_BASE / 8;

  set_immediate_dominator (CDI_DOMINATORS, l1_bb, entry_bb);
  set_immediate_dominator (CDI_DOMINATORS, l2_bb, l2_dom_bb);
  set_immediate_dominator (CDI_DOMINATORS, l0_bb, l1_bb);

  if (!broken_loop)
    {
      struct loop *loop = alloc_loop ();
      loop->header = l1_bb;
      loop->latch = cont_bb;
      add_loop (loop, l1_bb->loop_father);
      if (safelen == NULL_TREE)
        loop->safelen = INT_MAX;
      else
        {
          safelen = OMP_CLAUSE_SAFELEN_EXPR (safelen);
          if (TREE_CODE (safelen) != INTEGER_CST)
            loop->safelen = 0;
          else if (!tree_fits_uhwi_p (safelen)
                   || tree_to_uhwi (safelen) > INT_MAX)
            loop->safelen = INT_MAX;
          else
            loop->safelen = tree_to_uhwi (safelen);
          if (loop->safelen == 1)
            loop->safelen = 0;
        }
      if (simduid)
        {
          loop->simduid = OMP_CLAUSE__SIMDUID__DECL (simduid);
          cfun->has_simduid_loops = true;
        }
      /* If not -fno-tree-loop-vectorize, hint that we want to vectorize
         the loop.  */
      if ((flag_tree_loop_vectorize
           || (!global_options_set.x_flag_tree_loop_vectorize
               && !global_options_set.x_flag_tree_vectorize))
          && flag_tree_loop_optimize
          && loop->safelen > 1)
        {
          loop->force_vectorize = true;
          cfun->has_force_vectorize_loops = true;
        }
    }
  else if (simduid)
    cfun->has_simduid_loops = true;
}


/* Expand the OMP loop defined by REGION.  */

static void
expand_omp_for (struct omp_region *region, gimple inner_stmt)
{
  struct omp_for_data fd;
  struct omp_for_data_loop *loops;

  loops
    = (struct omp_for_data_loop *)
      alloca (gimple_omp_for_collapse (last_stmt (region->entry))
              * sizeof (struct omp_for_data_loop));
  extract_omp_for_data (as_a <gomp_for *> (last_stmt (region->entry)),
                        &fd, loops);
  region->sched_kind = fd.sched_kind;

  gcc_assert (EDGE_COUNT (region->entry->succs) == 2);
  BRANCH_EDGE (region->entry)->flags &= ~EDGE_ABNORMAL;
  FALLTHRU_EDGE (region->entry)->flags &= ~EDGE_ABNORMAL;
  if (region->cont)
    {
      gcc_assert (EDGE_COUNT (region->cont->succs) == 2);
      BRANCH_EDGE (region->cont)->flags &= ~EDGE_ABNORMAL;
      FALLTHRU_EDGE (region->cont)->flags &= ~EDGE_ABNORMAL;
    }
  else
    /* If there isn't a continue then this is a degerate case where
       the introduction of abnormal edges during lowering will prevent
       original loops from being detected.  Fix that up.  */
    loops_state_set (LOOPS_NEED_FIXUP);

  if (gimple_omp_for_kind (fd.for_stmt) & GF_OMP_FOR_SIMD)
    expand_omp_simd (region, &fd);
  else if (gimple_omp_for_kind (fd.for_stmt) == GF_OMP_FOR_KIND_CILKFOR)
    expand_cilk_for (region, &fd);
  else if (fd.sched_kind == OMP_CLAUSE_SCHEDULE_STATIC
           && !fd.have_ordered)
    {
      if (fd.chunk_size == NULL)
        expand_omp_for_static_nochunk (region, &fd, inner_stmt);
      else
        expand_omp_for_static_chunk (region, &fd, inner_stmt);
    }
  else
    {
      int fn_index, start_ix, next_ix;

      gcc_assert (gimple_omp_for_kind (fd.for_stmt)
                  == GF_OMP_FOR_KIND_FOR);
      if (fd.chunk_size == NULL
          && fd.sched_kind == OMP_CLAUSE_SCHEDULE_STATIC)
        fd.chunk_size = integer_zero_node;
      gcc_assert (fd.sched_kind != OMP_CLAUSE_SCHEDULE_AUTO);
      fn_index = (fd.sched_kind == OMP_CLAUSE_SCHEDULE_RUNTIME)
                  ? 3 : fd.sched_kind;
      fn_index += fd.have_ordered * 4;
      start_ix = ((int)BUILT_IN_GOMP_LOOP_STATIC_START) + fn_index;
      next_ix = ((int)BUILT_IN_GOMP_LOOP_STATIC_NEXT) + fn_index;
      if (fd.iter_type == long_long_unsigned_type_node)
        {
          start_ix += ((int)BUILT_IN_GOMP_LOOP_ULL_STATIC_START
                        - (int)BUILT_IN_GOMP_LOOP_STATIC_START);
          next_ix += ((int)BUILT_IN_GOMP_LOOP_ULL_STATIC_NEXT
                      - (int)BUILT_IN_GOMP_LOOP_STATIC_NEXT);
        }
      expand_omp_for_generic (region, &fd, (enum built_in_function) start_ix,
                              (enum built_in_function) next_ix, inner_stmt);
    }

  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_only_virtuals);
}


/* Expand code for an OpenMP sections directive.  In pseudo code, we generate

        v = GOMP_sections_start (n);
    L0:
        switch (v)
          {
          case 0:
            goto L2;
          case 1:
            section 1;
            goto L1;
          case 2:
            ...
          case n:
            ...
          default:
            abort ();
          }
    L1:
        v = GOMP_sections_next ();
        goto L0;
    L2:
        reduction;

    If this is a combined parallel sections, replace the call to
    GOMP_sections_start with call to GOMP_sections_next.  */

static void
expand_omp_sections (struct omp_region *region)
{
  tree t, u, vin = NULL, vmain, vnext, l2;
  unsigned len;
  basic_block entry_bb, l0_bb, l1_bb, l2_bb, default_bb;
  gimple_stmt_iterator si, switch_si;
  gomp_sections *sections_stmt;
  gimple stmt;
  gomp_continue *cont;
  edge_iterator ei;
  edge e;
  struct omp_region *inner;
  unsigned i, casei;
  bool exit_reachable = region->cont != NULL;

  gcc_assert (region->exit != NULL);
  entry_bb = region->entry;
  l0_bb = single_succ (entry_bb);
  l1_bb = region->cont;
  l2_bb = region->exit;
  if (single_pred_p (l2_bb) && single_pred (l2_bb) == l0_bb)
    l2 = gimple_block_label (l2_bb);
  else
    {
      /* This can happen if there are reductions.  */
      len = EDGE_COUNT (l0_bb->succs);
      gcc_assert (len > 0);
      e = EDGE_SUCC (l0_bb, len - 1);
      si = gsi_last_bb (e->dest);
      l2 = NULL_TREE;
      if (gsi_end_p (si)
          || gimple_code (gsi_stmt (si)) != GIMPLE_OMP_SECTION)
        l2 = gimple_block_label (e->dest);
      else
        FOR_EACH_EDGE (e, ei, l0_bb->succs)
          {
            si = gsi_last_bb (e->dest);
            if (gsi_end_p (si)
                || gimple_code (gsi_stmt (si)) != GIMPLE_OMP_SECTION)
              {
                l2 = gimple_block_label (e->dest);
                break;
              }
          }
    }
  if (exit_reachable)
    default_bb = create_empty_bb (l1_bb->prev_bb);
  else
    default_bb = create_empty_bb (l0_bb);

  /* We will build a switch() with enough cases for all the
     GIMPLE_OMP_SECTION regions, a '0' case to handle the end of more work
     and a default case to abort if something goes wrong.  */
  len = EDGE_COUNT (l0_bb->succs);

  /* Use vec::quick_push on label_vec throughout, since we know the size
     in advance.  */
  auto_vec<tree> label_vec (len);

  /* The call to GOMP_sections_start goes in ENTRY_BB, replacing the
     GIMPLE_OMP_SECTIONS statement.  */
  si = gsi_last_bb (entry_bb);
  sections_stmt = as_a <gomp_sections *> (gsi_stmt (si));
  gcc_assert (gimple_code (sections_stmt) == GIMPLE_OMP_SECTIONS);
  vin = gimple_omp_sections_control (sections_stmt);
  if (!is_combined_parallel (region))
    {
      /* If we are not inside a combined parallel+sections region,
         call GOMP_sections_start.  */
      t = build_int_cst (unsigned_type_node, len - 1);
      u = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_START);
      stmt = gimple_build_call (u, 1, t);
    }
  else
    {
      /* Otherwise, call GOMP_sections_next.  */
      u = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_NEXT);
      stmt = gimple_build_call (u, 0);
    }
  gimple_call_set_lhs (stmt, vin);
  gsi_insert_after (&si, stmt, GSI_SAME_STMT);
  gsi_remove (&si, true);

  /* The switch() statement replacing GIMPLE_OMP_SECTIONS_SWITCH goes in
     L0_BB.  */
  switch_si = gsi_last_bb (l0_bb);
  gcc_assert (gimple_code (gsi_stmt (switch_si)) == GIMPLE_OMP_SECTIONS_SWITCH);
  if (exit_reachable)
    {
      cont = as_a <gomp_continue *> (last_stmt (l1_bb));
      gcc_assert (gimple_code (cont) == GIMPLE_OMP_CONTINUE);
      vmain = gimple_omp_continue_control_use (cont);
      vnext = gimple_omp_continue_control_def (cont);
    }
  else
    {
      vmain = vin;
      vnext = NULL_TREE;
    }

  t = build_case_label (build_int_cst (unsigned_type_node, 0), NULL, l2);
  label_vec.quick_push (t);
  i = 1;

  /* Convert each GIMPLE_OMP_SECTION into a CASE_LABEL_EXPR.  */
  for (inner = region->inner, casei = 1;
       inner;
       inner = inner->next, i++, casei++)
    {
      basic_block s_entry_bb, s_exit_bb;

      /* Skip optional reduction region.  */
      if (inner->type == GIMPLE_OMP_ATOMIC_LOAD)
        {
          --i;
          --casei;
          continue;
        }

      s_entry_bb = inner->entry;
      s_exit_bb = inner->exit;

      t = gimple_block_label (s_entry_bb);
      u = build_int_cst (unsigned_type_node, casei);
      u = build_case_label (u, NULL, t);
      label_vec.quick_push (u);

      si = gsi_last_bb (s_entry_bb);
      gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_SECTION);
      gcc_assert (i < len || gimple_omp_section_last_p (gsi_stmt (si)));
      gsi_remove (&si, true);
      single_succ_edge (s_entry_bb)->flags = EDGE_FALLTHRU;

      if (s_exit_bb == NULL)
        continue;

      si = gsi_last_bb (s_exit_bb);
      gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_RETURN);
      gsi_remove (&si, true);

      single_succ_edge (s_exit_bb)->flags = EDGE_FALLTHRU;
    }

  /* Error handling code goes in DEFAULT_BB.  */
  t = gimple_block_label (default_bb);
  u = build_case_label (NULL, NULL, t);
  make_edge (l0_bb, default_bb, 0);
  add_bb_to_loop (default_bb, current_loops->tree_root);

  stmt = gimple_build_switch (vmain, u, label_vec);
  gsi_insert_after (&switch_si, stmt, GSI_SAME_STMT);
  gsi_remove (&switch_si, true);

  si = gsi_start_bb (default_bb);
  stmt = gimple_build_call (builtin_decl_explicit (BUILT_IN_TRAP), 0);
  gsi_insert_after (&si, stmt, GSI_CONTINUE_LINKING);

  if (exit_reachable)
    {
      tree bfn_decl;

      /* Code to get the next section goes in L1_BB.  */
      si = gsi_last_bb (l1_bb);
      gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_CONTINUE);

      bfn_decl = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_NEXT);
      stmt = gimple_build_call (bfn_decl, 0);
      gimple_call_set_lhs (stmt, vnext);
      gsi_insert_after (&si, stmt, GSI_SAME_STMT);
      gsi_remove (&si, true);

      single_succ_edge (l1_bb)->flags = EDGE_FALLTHRU;
    }

  /* Cleanup function replaces GIMPLE_OMP_RETURN in EXIT_BB.  */
  si = gsi_last_bb (l2_bb);
  if (gimple_omp_return_nowait_p (gsi_stmt (si)))
    t = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_END_NOWAIT);
  else if (gimple_omp_return_lhs (gsi_stmt (si)))
    t = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_END_CANCEL);
  else
    t = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_END);
  stmt = gimple_build_call (t, 0);
  if (gimple_omp_return_lhs (gsi_stmt (si)))
    gimple_call_set_lhs (stmt, gimple_omp_return_lhs (gsi_stmt (si)));
  gsi_insert_after (&si, stmt, GSI_SAME_STMT);
  gsi_remove (&si, true);

  set_immediate_dominator (CDI_DOMINATORS, default_bb, l0_bb);
}


/* Expand code for an OpenMP single directive.  We've already expanded
   much of the code, here we simply place the GOMP_barrier call.  */

static void
expand_omp_single (struct omp_region *region)
{
  basic_block entry_bb, exit_bb;
  gimple_stmt_iterator si;

  entry_bb = region->entry;
  exit_bb = region->exit;

  si = gsi_last_bb (entry_bb);
  gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_SINGLE);
  gsi_remove (&si, true);
  single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;

  si = gsi_last_bb (exit_bb);
  if (!gimple_omp_return_nowait_p (gsi_stmt (si)))
    {
      tree t = gimple_omp_return_lhs (gsi_stmt (si));
      gsi_insert_after (&si, build_omp_barrier (t), GSI_SAME_STMT);
    }
  gsi_remove (&si, true);
  single_succ_edge (exit_bb)->flags = EDGE_FALLTHRU;
}


/* Generic expansion for OpenMP synchronization directives: master,
   ordered and critical.  All we need to do here is remove the entry
   and exit markers for REGION.  */

static void
expand_omp_synch (struct omp_region *region)
{
  basic_block entry_bb, exit_bb;
  gimple_stmt_iterator si;

  entry_bb = region->entry;
  exit_bb = region->exit;

  si = gsi_last_bb (entry_bb);
  gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_SINGLE
              || gimple_code (gsi_stmt (si)) == GIMPLE_OMP_MASTER
              || gimple_code (gsi_stmt (si)) == GIMPLE_OMP_TASKGROUP
              || gimple_code (gsi_stmt (si)) == GIMPLE_OMP_ORDERED
              || gimple_code (gsi_stmt (si)) == GIMPLE_OMP_CRITICAL
              || gimple_code (gsi_stmt (si)) == GIMPLE_OMP_TEAMS);
  gsi_remove (&si, true);
  single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;

  if (exit_bb)
    {
      si = gsi_last_bb (exit_bb);
      gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_RETURN);
      gsi_remove (&si, true);
      single_succ_edge (exit_bb)->flags = EDGE_FALLTHRU;
    }
}

/* A subroutine of expand_omp_atomic.  Attempt to implement the atomic
   operation as a normal volatile load.  */

static bool
expand_omp_atomic_load (basic_block load_bb, tree addr,
                        tree loaded_val, int index)
{
  enum built_in_function tmpbase;
  gimple_stmt_iterator gsi;
  basic_block store_bb;
  location_t loc;
  gimple stmt;
  tree decl, call, type, itype;

  gsi = gsi_last_bb (load_bb);
  stmt = gsi_stmt (gsi);
  gcc_assert (gimple_code (stmt) == GIMPLE_OMP_ATOMIC_LOAD);
  loc = gimple_location (stmt);

  /* ??? If the target does not implement atomic_load_optab[mode], and mode
     is smaller than word size, then expand_atomic_load assumes that the load
     is atomic.  We could avoid the builtin entirely in this case.  */

  tmpbase = (enum built_in_function) (BUILT_IN_ATOMIC_LOAD_N + index + 1);
  decl = builtin_decl_explicit (tmpbase);
  if (decl == NULL_TREE)
    return false;

  type = TREE_TYPE (loaded_val);
  itype = TREE_TYPE (TREE_TYPE (decl));

  call = build_call_expr_loc (loc, decl, 2, addr,
                              build_int_cst (NULL,
                                             gimple_omp_atomic_seq_cst_p (stmt)
                                             ? MEMMODEL_SEQ_CST
                                             : MEMMODEL_RELAXED));
  if (!useless_type_conversion_p (type, itype))
    call = fold_build1_loc (loc, VIEW_CONVERT_EXPR, type, call);
  call = build2_loc (loc, MODIFY_EXPR, void_type_node, loaded_val, call);

  force_gimple_operand_gsi (&gsi, call, true, NULL_TREE, true, GSI_SAME_STMT);
  gsi_remove (&gsi, true);

  store_bb = single_succ (load_bb);
  gsi = gsi_last_bb (store_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_ATOMIC_STORE);
  gsi_remove (&gsi, true);

  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_no_phi);

  return true;
}

/* A subroutine of expand_omp_atomic.  Attempt to implement the atomic
   operation as a normal volatile store.  */

static bool
expand_omp_atomic_store (basic_block load_bb, tree addr,
                         tree loaded_val, tree stored_val, int index)
{
  enum built_in_function tmpbase;
  gimple_stmt_iterator gsi;
  basic_block store_bb = single_succ (load_bb);
  location_t loc;
  gimple stmt;
  tree decl, call, type, itype;
  machine_mode imode;
  bool exchange;

  gsi = gsi_last_bb (load_bb);
  stmt = gsi_stmt (gsi);
  gcc_assert (gimple_code (stmt) == GIMPLE_OMP_ATOMIC_LOAD);

  /* If the load value is needed, then this isn't a store but an exchange.  */
  exchange = gimple_omp_atomic_need_value_p (stmt);

  gsi = gsi_last_bb (store_bb);
  stmt = gsi_stmt (gsi);
  gcc_assert (gimple_code (stmt) == GIMPLE_OMP_ATOMIC_STORE);
  loc = gimple_location (stmt);

  /* ??? If the target does not implement atomic_store_optab[mode], and mode
     is smaller than word size, then expand_atomic_store assumes that the store
     is atomic.  We could avoid the builtin entirely in this case.  */

  tmpbase = (exchange ? BUILT_IN_ATOMIC_EXCHANGE_N : BUILT_IN_ATOMIC_STORE_N);
  tmpbase = (enum built_in_function) ((int) tmpbase + index + 1);
  decl = builtin_decl_explicit (tmpbase);
  if (decl == NULL_TREE)
    return false;

  type = TREE_TYPE (stored_val);

  /* Dig out the type of the function's second argument.  */
  itype = TREE_TYPE (decl);
  itype = TYPE_ARG_TYPES (itype);
  itype = TREE_CHAIN (itype);
  itype = TREE_VALUE (itype);
  imode = TYPE_MODE (itype);

  if (exchange && !can_atomic_exchange_p (imode, true))
    return false;

  if (!useless_type_conversion_p (itype, type))
    stored_val = fold_build1_loc (loc, VIEW_CONVERT_EXPR, itype, stored_val);
  call = build_call_expr_loc (loc, decl, 3, addr, stored_val,
                              build_int_cst (NULL,
                                             gimple_omp_atomic_seq_cst_p (stmt)
                                             ? MEMMODEL_SEQ_CST
                                             : MEMMODEL_RELAXED));
  if (exchange)
    {
      if (!useless_type_conversion_p (type, itype))
        call = build1_loc (loc, VIEW_CONVERT_EXPR, type, call);
      call = build2_loc (loc, MODIFY_EXPR, void_type_node, loaded_val, call);
    }

  force_gimple_operand_gsi (&gsi, call, true, NULL_TREE, true, GSI_SAME_STMT);
  gsi_remove (&gsi, true);

  /* Remove the GIMPLE_OMP_ATOMIC_LOAD that we verified above.  */
  gsi = gsi_last_bb (load_bb);
  gsi_remove (&gsi, true);

  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_no_phi);

  return true;
}

/* A subroutine of expand_omp_atomic.  Attempt to implement the atomic
   operation as a __atomic_fetch_op builtin.  INDEX is log2 of the
   size of the data type, and thus usable to find the index of the builtin
   decl.  Returns false if the expression is not of the proper form.  */

static bool
expand_omp_atomic_fetch_op (basic_block load_bb,
                            tree addr, tree loaded_val,
                            tree stored_val, int index)
{
  enum built_in_function oldbase, newbase, tmpbase;
  tree decl, itype, call;
  tree lhs, rhs;
  basic_block store_bb = single_succ (load_bb);
  gimple_stmt_iterator gsi;
  gimple stmt;
  location_t loc;
  enum tree_code code;
  bool need_old, need_new;
  machine_mode imode;
  bool seq_cst;

  /* We expect to find the following sequences:

   load_bb:
       GIMPLE_OMP_ATOMIC_LOAD (tmp, mem)

   store_bb:
       val = tmp OP something; (or: something OP tmp)
       GIMPLE_OMP_STORE (val)

  ???FIXME: Allow a more flexible sequence.
  Perhaps use data flow to pick the statements.

  */

  gsi = gsi_after_labels (store_bb);
  stmt = gsi_stmt (gsi);
  loc = gimple_location (stmt);
  if (!is_gimple_assign (stmt))
    return false;
  gsi_next (&gsi);
  if (gimple_code (gsi_stmt (gsi)) != GIMPLE_OMP_ATOMIC_STORE)
    return false;
  need_new = gimple_omp_atomic_need_value_p (gsi_stmt (gsi));
  need_old = gimple_omp_atomic_need_value_p (last_stmt (load_bb));
  seq_cst = gimple_omp_atomic_seq_cst_p (last_stmt (load_bb));
  gcc_checking_assert (!need_old || !need_new);

  if (!operand_equal_p (gimple_assign_lhs (stmt), stored_val, 0))
    return false;

  /* Check for one of the supported fetch-op operations.  */
  code = gimple_assign_rhs_code (stmt);
  switch (code)
    {
    case PLUS_EXPR:
    case POINTER_PLUS_EXPR:
      oldbase = BUILT_IN_ATOMIC_FETCH_ADD_N;
      newbase = BUILT_IN_ATOMIC_ADD_FETCH_N;
      break;
    case MINUS_EXPR:
      oldbase = BUILT_IN_ATOMIC_FETCH_SUB_N;
      newbase = BUILT_IN_ATOMIC_SUB_FETCH_N;
      break;
    case BIT_AND_EXPR:
      oldbase = BUILT_IN_ATOMIC_FETCH_AND_N;
      newbase = BUILT_IN_ATOMIC_AND_FETCH_N;
      break;
    case BIT_IOR_EXPR:
      oldbase = BUILT_IN_ATOMIC_FETCH_OR_N;
      newbase = BUILT_IN_ATOMIC_OR_FETCH_N;
      break;
    case BIT_XOR_EXPR:
      oldbase = BUILT_IN_ATOMIC_FETCH_XOR_N;
      newbase = BUILT_IN_ATOMIC_XOR_FETCH_N;
      break;
    default:
      return false;
    }

  /* Make sure the expression is of the proper form.  */
  if (operand_equal_p (gimple_assign_rhs1 (stmt), loaded_val, 0))
    rhs = gimple_assign_rhs2 (stmt);
  else if (commutative_tree_code (gimple_assign_rhs_code (stmt))
           && operand_equal_p (gimple_assign_rhs2 (stmt), loaded_val, 0))
    rhs = gimple_assign_rhs1 (stmt);
  else
    return false;

  tmpbase = ((enum built_in_function)
             ((need_new ? newbase : oldbase) + index + 1));
  decl = builtin_decl_explicit (tmpbase);
  if (decl == NULL_TREE)
    return false;
  itype = TREE_TYPE (TREE_TYPE (decl));
  imode = TYPE_MODE (itype);

  /* We could test all of the various optabs involved, but the fact of the
     matter is that (with the exception of i486 vs i586 and xadd) all targets
     that support any atomic operaton optab also implements compare-and-swap.
     Let optabs.c take care of expanding any compare-and-swap loop.  */
  if (!can_compare_and_swap_p (imode, true))
    return false;

  gsi = gsi_last_bb (load_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_ATOMIC_LOAD);

  /* OpenMP does not imply any barrier-like semantics on its atomic ops.
     It only requires that the operation happen atomically.  Thus we can
     use the RELAXED memory model.  */
  call = build_call_expr_loc (loc, decl, 3, addr,
                              fold_convert_loc (loc, itype, rhs),
                              build_int_cst (NULL,
                                             seq_cst ? MEMMODEL_SEQ_CST
                                                     : MEMMODEL_RELAXED));

  if (need_old || need_new)
    {
      lhs = need_old ? loaded_val : stored_val;
      call = fold_convert_loc (loc, TREE_TYPE (lhs), call);
      call = build2_loc (loc, MODIFY_EXPR, void_type_node, lhs, call);
    }
  else
    call = fold_convert_loc (loc, void_type_node, call);
  force_gimple_operand_gsi (&gsi, call, true, NULL_TREE, true, GSI_SAME_STMT);
  gsi_remove (&gsi, true);

  gsi = gsi_last_bb (store_bb);
  gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_ATOMIC_STORE);
  gsi_remove (&gsi, true);
  gsi = gsi_last_bb (store_bb);
  gsi_remove (&gsi, true);

  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_no_phi);

  return true;
}

/* A subroutine of expand_omp_atomic.  Implement the atomic operation as:

      oldval = *addr;
      repeat:
        newval = rhs;    // with oldval replacing *addr in rhs
        oldval = __sync_val_compare_and_swap (addr, oldval, newval);
        if (oldval != newval)
          goto repeat;

   INDEX is log2 of the size of the data type, and thus usable to find the
   index of the builtin decl.  */

static bool
expand_omp_atomic_pipeline (basic_block load_bb, basic_block store_bb,
                            tree addr, tree loaded_val, tree stored_val,
                            int index)
{
  tree loadedi, storedi, initial, new_storedi, old_vali;
  tree type, itype, cmpxchg, iaddr;
  gimple_stmt_iterator si;
  basic_block loop_header = single_succ (load_bb);
  gimple phi, stmt;
  edge e;
  enum built_in_function fncode;

  /* ??? We need a non-pointer interface to __atomic_compare_exchange in
     order to use the RELAXED memory model effectively.  */
  fncode = (enum built_in_function)((int)BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_N
                                    + index + 1);
  cmpxchg = builtin_decl_explicit (fncode);
  if (cmpxchg == NULL_TREE)
    return false;
  type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (addr)));
  itype = TREE_TYPE (TREE_TYPE (cmpxchg));

  if (!can_compare_and_swap_p (TYPE_MODE (itype), true))
    return false;

  /* Load the initial value, replacing the GIMPLE_OMP_ATOMIC_LOAD.  */
  si = gsi_last_bb (load_bb);
  gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_ATOMIC_LOAD);

  /* For floating-point values, we'll need to view-convert them to integers
     so that we can perform the atomic compare and swap.  Simplify the
     following code by always setting up the "i"ntegral variables.  */
  if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
    {
      tree iaddr_val;

      iaddr = create_tmp_reg (build_pointer_type_for_mode (itype, ptr_mode,
                                                           true));
      iaddr_val
        = force_gimple_operand_gsi (&si,
                                    fold_convert (TREE_TYPE (iaddr), addr),
                                    false, NULL_TREE, true, GSI_SAME_STMT);
      stmt = gimple_build_assign (iaddr, iaddr_val);
      gsi_insert_before (&si, stmt, GSI_SAME_STMT);
      loadedi = create_tmp_var (itype);
      if (gimple_in_ssa_p (cfun))
        loadedi = make_ssa_name (loadedi);
    }
  else
    {
      iaddr = addr;
      loadedi = loaded_val;
    }

  fncode = (enum built_in_function) (BUILT_IN_ATOMIC_LOAD_N + index + 1);
  tree loaddecl = builtin_decl_explicit (fncode);
  if (loaddecl)
    initial
      = fold_convert (TREE_TYPE (TREE_TYPE (iaddr)),
                      build_call_expr (loaddecl, 2, iaddr,
                                       build_int_cst (NULL_TREE,
                                                      MEMMODEL_RELAXED)));
  else
    initial = build2 (MEM_REF, TREE_TYPE (TREE_TYPE (iaddr)), iaddr,
                      build_int_cst (TREE_TYPE (iaddr), 0));

  initial
    = force_gimple_operand_gsi (&si, initial, true, NULL_TREE, true,
                                GSI_SAME_STMT);

  /* Move the value to the LOADEDI temporary.  */
  if (gimple_in_ssa_p (cfun))
    {
      gcc_assert (gimple_seq_empty_p (phi_nodes (loop_header)));
      phi = create_phi_node (loadedi, loop_header);
      SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, single_succ_edge (load_bb)),
               initial);
    }
  else
    gsi_insert_before (&si,
                       gimple_build_assign (loadedi, initial),
                       GSI_SAME_STMT);
  if (loadedi != loaded_val)
    {
      gimple_stmt_iterator gsi2;
      tree x;

      x = build1 (VIEW_CONVERT_EXPR, type, loadedi);
      gsi2 = gsi_start_bb (loop_header);
      if (gimple_in_ssa_p (cfun))
        {
          gassign *stmt;
          x = force_gimple_operand_gsi (&gsi2, x, true, NULL_TREE,
                                        true, GSI_SAME_STMT);
          stmt = gimple_build_assign (loaded_val, x);
          gsi_insert_before (&gsi2, stmt, GSI_SAME_STMT);
        }
      else
        {
          x = build2 (MODIFY_EXPR, TREE_TYPE (loaded_val), loaded_val, x);
          force_gimple_operand_gsi (&gsi2, x, true, NULL_TREE,
                                    true, GSI_SAME_STMT);
        }
    }
  gsi_remove (&si, true);

  si = gsi_last_bb (store_bb);
  gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_ATOMIC_STORE);

  if (iaddr == addr)
    storedi = stored_val;
  else
    storedi =
      force_gimple_operand_gsi (&si,
                                build1 (VIEW_CONVERT_EXPR, itype,
                                        stored_val), true, NULL_TREE, true,
                                GSI_SAME_STMT);

  /* Build the compare&swap statement.  */
  new_storedi = build_call_expr (cmpxchg, 3, iaddr, loadedi, storedi);
  new_storedi = force_gimple_operand_gsi (&si,
                                          fold_convert (TREE_TYPE (loadedi),
                                                        new_storedi),
                                          true, NULL_TREE,
                                          true, GSI_SAME_STMT);

  if (gimple_in_ssa_p (cfun))
    old_vali = loadedi;
  else
    {
      old_vali = create_tmp_var (TREE_TYPE (loadedi));
      stmt = gimple_build_assign (old_vali, loadedi);
      gsi_insert_before (&si, stmt, GSI_SAME_STMT);

      stmt = gimple_build_assign (loadedi, new_storedi);
      gsi_insert_before (&si, stmt, GSI_SAME_STMT);
    }

  /* Note that we always perform the comparison as an integer, even for
     floating point.  This allows the atomic operation to properly
     succeed even with NaNs and -0.0.  */
  stmt = gimple_build_cond_empty
           (build2 (NE_EXPR, boolean_type_node,
                    new_storedi, old_vali));
  gsi_insert_before (&si, stmt, GSI_SAME_STMT);

  /* Update cfg.  */
  e = single_succ_edge (store_bb);
  e->flags &= ~EDGE_FALLTHRU;
  e->flags |= EDGE_FALSE_VALUE;

  e = make_edge (store_bb, loop_header, EDGE_TRUE_VALUE);

  /* Copy the new value to loadedi (we already did that before the condition
     if we are not in SSA).  */
  if (gimple_in_ssa_p (cfun))
    {
      phi = gimple_seq_first_stmt (phi_nodes (loop_header));
      SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, e), new_storedi);
    }

  /* Remove GIMPLE_OMP_ATOMIC_STORE.  */
  gsi_remove (&si, true);

  struct loop *loop = alloc_loop ();
  loop->header = loop_header;
  loop->latch = store_bb;
  add_loop (loop, loop_header->loop_father);

  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_no_phi);

  return true;
}

/* A subroutine of expand_omp_atomic.  Implement the atomic operation as:

                                  GOMP_atomic_start ();
                                  *addr = rhs;
                                  GOMP_atomic_end ();

   The result is not globally atomic, but works so long as all parallel
   references are within #pragma omp atomic directives.  According to
   responses received from omp@openmp.org, appears to be within spec.
   Which makes sense, since that's how several other compilers handle
   this situation as well.
   LOADED_VAL and ADDR are the operands of GIMPLE_OMP_ATOMIC_LOAD we're
   expanding.  STORED_VAL is the operand of the matching
   GIMPLE_OMP_ATOMIC_STORE.

   We replace
   GIMPLE_OMP_ATOMIC_LOAD (loaded_val, addr) with
   loaded_val = *addr;

   and replace
   GIMPLE_OMP_ATOMIC_STORE (stored_val)  with
   *addr = stored_val;
*/

static bool
expand_omp_atomic_mutex (basic_block load_bb, basic_block store_bb,
                         tree addr, tree loaded_val, tree stored_val)
{
  gimple_stmt_iterator si;
  gassign *stmt;
  tree t;

  si = gsi_last_bb (load_bb);
  gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_ATOMIC_LOAD);

  t = builtin_decl_explicit (BUILT_IN_GOMP_ATOMIC_START);
  t = build_call_expr (t, 0);
  force_gimple_operand_gsi (&si, t, true, NULL_TREE, true, GSI_SAME_STMT);

  stmt = gimple_build_assign (loaded_val, build_simple_mem_ref (addr));
  gsi_insert_before (&si, stmt, GSI_SAME_STMT);
  gsi_remove (&si, true);

  si = gsi_last_bb (store_bb);
  gcc_assert (gimple_code (gsi_stmt (si)) == GIMPLE_OMP_ATOMIC_STORE);

  stmt = gimple_build_assign (build_simple_mem_ref (unshare_expr (addr)),
                              stored_val);
  gsi_insert_before (&si, stmt, GSI_SAME_STMT);

  t = builtin_decl_explicit (BUILT_IN_GOMP_ATOMIC_END);
  t = build_call_expr (t, 0);
  force_gimple_operand_gsi (&si, t, true, NULL_TREE, true, GSI_SAME_STMT);
  gsi_remove (&si, true);

  if (gimple_in_ssa_p (cfun))
    update_ssa (TODO_update_ssa_no_phi);
  return true;
}

/* Expand an GIMPLE_OMP_ATOMIC statement.  We try to expand
   using expand_omp_atomic_fetch_op. If it failed, we try to
   call expand_omp_atomic_pipeline, and if it fails too, the
   ultimate fallback is wrapping the operation in a mutex
   (expand_omp_atomic_mutex).  REGION is the atomic region built
   by build_omp_regions_1().  */

static void
expand_omp_atomic (struct omp_region *region)
{
  basic_block load_bb = region->entry, store_bb = region->exit;
  gomp_atomic_load *load = as_a <gomp_atomic_load *> (last_stmt (load_bb));
  gomp_atomic_store *store = as_a <gomp_atomic_store *> (last_stmt (store_bb));
  tree loaded_val = gimple_omp_atomic_load_lhs (load);
  tree addr = gimple_omp_atomic_load_rhs (load);
  tree stored_val = gimple_omp_atomic_store_val (store);
  tree type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (addr)));
  HOST_WIDE_INT index;

  /* Make sure the type is one of the supported sizes.  */
  index = tree_to_uhwi (TYPE_SIZE_UNIT (type));
  index = exact_log2 (index);
  if (index >= 0 && index <= 4)
    {
      unsigned int align = TYPE_ALIGN_UNIT (type);

      /* __sync builtins require strict data alignment.  */
      if (exact_log2 (align) >= index)
        {
          /* Atomic load.  */
          if (loaded_val == stored_val
              && (GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT
                  || GET_MODE_CLASS (TYPE_MODE (type)) == MODE_FLOAT)
              && GET_MODE_BITSIZE (TYPE_MODE (type)) <= BITS_PER_WORD
              && expand_omp_atomic_load (load_bb, addr, loaded_val, index))
            return;

          /* Atomic store.  */
          if ((GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT
               || GET_MODE_CLASS (TYPE_MODE (type)) == MODE_FLOAT)
              && GET_MODE_BITSIZE (TYPE_MODE (type)) <= BITS_PER_WORD
              && store_bb == single_succ (load_bb)
              && first_stmt (store_bb) == store
              && expand_omp_atomic_store (load_bb, addr, loaded_val,
                                          stored_val, index))
            return;

          /* When possible, use specialized atomic update functions.  */
          if ((INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
              && store_bb == single_succ (load_bb)
              && expand_omp_atomic_fetch_op (load_bb, addr,
                                             loaded_val, stored_val, index))
            return;

          /* If we don't have specialized __sync builtins, try and implement
             as a compare and swap loop.  */
          if (expand_omp_atomic_pipeline (load_bb, store_bb, addr,
                                          loaded_val, stored_val, index))
            return;
        }
    }

  /* The ultimate fallback is wrapping the operation in a mutex.  */
  expand_omp_atomic_mutex (load_bb, store_bb, addr, loaded_val, stored_val);
}


/* Expand the GIMPLE_OMP_TARGET starting at REGION.  */

static void
expand_omp_target (struct omp_region *region)
{
  basic_block entry_bb, exit_bb, new_bb;
  struct function *child_cfun;
  tree child_fn, block, t;
  gimple_stmt_iterator gsi;
  gomp_target *entry_stmt;
  gimple stmt;
  edge e;
  bool offloaded, data_region;

  entry_stmt = as_a <gomp_target *> (last_stmt (region->entry));
  new_bb = region->entry;

  offloaded = is_gimple_omp_offloaded (entry_stmt);
  switch (gimple_omp_target_kind (entry_stmt))
    {
    case GF_OMP_TARGET_KIND_REGION:
    case GF_OMP_TARGET_KIND_UPDATE:
    case GF_OMP_TARGET_KIND_OACC_PARALLEL:
    case GF_OMP_TARGET_KIND_OACC_KERNELS:
    case GF_OMP_TARGET_KIND_OACC_UPDATE:
    case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA:
      data_region = false;
      break;
    case GF_OMP_TARGET_KIND_DATA:
    case GF_OMP_TARGET_KIND_OACC_DATA:
      data_region = true;
      break;
    default:
      gcc_unreachable ();
    }

  child_fn = NULL_TREE;
  child_cfun = NULL;
  if (offloaded)
    {
      child_fn = gimple_omp_target_child_fn (entry_stmt);
      child_cfun = DECL_STRUCT_FUNCTION (child_fn);
    }

  /* Supported by expand_omp_taskreg, but not here.  */
  if (child_cfun != NULL)
    gcc_checking_assert (!child_cfun->cfg);
  gcc_checking_assert (!gimple_in_ssa_p (cfun));

  entry_bb = region->entry;
  exit_bb = region->exit;

  if (offloaded)
    {
      unsigned srcidx, dstidx, num;

      /* If the offloading region needs data sent from the parent
         function, then the very first statement (except possible
         tree profile counter updates) of the offloading body
         is a copy assignment .OMP_DATA_I = &.OMP_DATA_O.  Since
         &.OMP_DATA_O is passed as an argument to the child function,
         we need to replace it with the argument as seen by the child
         function.

         In most cases, this will end up being the identity assignment
         .OMP_DATA_I = .OMP_DATA_I.  However, if the offloading body had
         a function call that has been inlined, the original PARM_DECL
         .OMP_DATA_I may have been converted into a different local
         variable.  In which case, we need to keep the assignment.  */
      tree data_arg = gimple_omp_target_data_arg (entry_stmt);
      if (data_arg)
        {
          basic_block entry_succ_bb = single_succ (entry_bb);
          gimple_stmt_iterator gsi;
          tree arg;
          gimple tgtcopy_stmt = NULL;
          tree sender = TREE_VEC_ELT (data_arg, 0);

          for (gsi = gsi_start_bb (entry_succ_bb); ; gsi_next (&gsi))
            {
              gcc_assert (!gsi_end_p (gsi));
              stmt = gsi_stmt (gsi);
              if (gimple_code (stmt) != GIMPLE_ASSIGN)
                continue;

              if (gimple_num_ops (stmt) == 2)
                {
                  tree arg = gimple_assign_rhs1 (stmt);

                  /* We're ignoring the subcode because we're
                     effectively doing a STRIP_NOPS.  */

                  if (TREE_CODE (arg) == ADDR_EXPR
                      && TREE_OPERAND (arg, 0) == sender)
                    {
                      tgtcopy_stmt = stmt;
                      break;
                    }
                }
            }

          gcc_assert (tgtcopy_stmt != NULL);
          arg = DECL_ARGUMENTS (child_fn);

          gcc_assert (gimple_assign_lhs (tgtcopy_stmt) == arg);
          gsi_remove (&gsi, true);
        }

      /* Declare local variables needed in CHILD_CFUN.  */
      block = DECL_INITIAL (child_fn);
      BLOCK_VARS (block) = vec2chain (child_cfun->local_decls);
      /* The gimplifier could record temporaries in the offloading block
         rather than in containing function's local_decls chain,
         which would mean cgraph missed finalizing them.  Do it now.  */
      for (t = BLOCK_VARS (block); t; t = DECL_CHAIN (t))
        if (TREE_CODE (t) == VAR_DECL
            && TREE_STATIC (t)
            && !DECL_EXTERNAL (t))
          varpool_node::finalize_decl (t);
      DECL_SAVED_TREE (child_fn) = NULL;
      /* We'll create a CFG for child_fn, so no gimple body is needed.  */
      gimple_set_body (child_fn, NULL);
      TREE_USED (block) = 1;

      /* Reset DECL_CONTEXT on function arguments.  */
      for (t = DECL_ARGUMENTS (child_fn); t; t = DECL_CHAIN (t))
        DECL_CONTEXT (t) = child_fn;

      /* Split ENTRY_BB at GIMPLE_*,
         so that it can be moved to the child function.  */
      gsi = gsi_last_bb (entry_bb);
      stmt = gsi_stmt (gsi);
      gcc_assert (stmt
                  && gimple_code (stmt) == gimple_code (entry_stmt));
      e = split_block (entry_bb, stmt);
      gsi_remove (&gsi, true);
      entry_bb = e->dest;
      single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;

      /* Convert GIMPLE_OMP_RETURN into a RETURN_EXPR.  */
      if (exit_bb)
        {
          gsi = gsi_last_bb (exit_bb);
          gcc_assert (!gsi_end_p (gsi)
                      && gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_RETURN);
          stmt = gimple_build_return (NULL);
          gsi_insert_after (&gsi, stmt, GSI_SAME_STMT);
          gsi_remove (&gsi, true);
        }

      /* Move the offloading region into CHILD_CFUN.  */

      block = gimple_block (entry_stmt);

      new_bb = move_sese_region_to_fn (child_cfun, entry_bb, exit_bb, block);
      if (exit_bb)
        single_succ_edge (new_bb)->flags = EDGE_FALLTHRU;
      /* When the OMP expansion process cannot guarantee an up-to-date
         loop tree arrange for the child function to fixup loops.  */
      if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
        child_cfun->x_current_loops->state |= LOOPS_NEED_FIXUP;

      /* Remove non-local VAR_DECLs from child_cfun->local_decls list.  */
      num = vec_safe_length (child_cfun->local_decls);
      for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
        {
          t = (*child_cfun->local_decls)[srcidx];
          if (DECL_CONTEXT (t) == cfun->decl)
            continue;
          if (srcidx != dstidx)
            (*child_cfun->local_decls)[dstidx] = t;
          dstidx++;
        }
      if (dstidx != num)
        vec_safe_truncate (child_cfun->local_decls, dstidx);

      /* Inform the callgraph about the new function.  */
      child_cfun->curr_properties = cfun->curr_properties;
      child_cfun->has_simduid_loops |= cfun->has_simduid_loops;
      child_cfun->has_force_vectorize_loops |= cfun->has_force_vectorize_loops;
      cgraph_node *node = cgraph_node::get_create (child_fn);
      node->parallelized_function = 1;
      cgraph_node::add_new_function (child_fn, true);

#ifdef ENABLE_OFFLOADING
      /* Add the new function to the offload table.  */
      vec_safe_push (offload_funcs, child_fn);
#endif

      /* Fix the callgraph edges for child_cfun.  Those for cfun will be
         fixed in a following pass.  */
      push_cfun (child_cfun);
      cgraph_edge::rebuild_edges ();

#ifdef ENABLE_OFFLOADING
      /* Prevent IPA from removing child_fn as unreachable, since there are no
         refs from the parent function to child_fn in offload LTO mode.  */
      cgraph_node::get (child_fn)->mark_force_output ();
#endif

      /* Some EH regions might become dead, see PR34608.  If
         pass_cleanup_cfg isn't the first pass to happen with the
         new child, these dead EH edges might cause problems.
         Clean them up now.  */
      if (flag_exceptions)
        {
          basic_block bb;
          bool changed = false;

          FOR_EACH_BB_FN (bb, cfun)
            changed |= gimple_purge_dead_eh_edges (bb);
          if (changed)
            cleanup_tree_cfg ();
        }
#ifdef ENABLE_CHECKING
      if (!loops_state_satisfies_p (LOOPS_NEED_FIXUP))
        verify_loop_structure ();
#endif
      pop_cfun ();
    }

  /* Emit a library call to launch the offloading region, or do data
     transfers.  */
  tree t1, t2, t3, t4, device, cond, c, clauses;
  enum built_in_function start_ix;
  location_t clause_loc;

  switch (gimple_omp_target_kind (entry_stmt))
    {
    case GF_OMP_TARGET_KIND_REGION:
      start_ix = BUILT_IN_GOMP_TARGET;
      break;
    case GF_OMP_TARGET_KIND_DATA:
      start_ix = BUILT_IN_GOMP_TARGET_DATA;
      break;
    case GF_OMP_TARGET_KIND_UPDATE:
      start_ix = BUILT_IN_GOMP_TARGET_UPDATE;
      break;
    case GF_OMP_TARGET_KIND_OACC_PARALLEL:
    case GF_OMP_TARGET_KIND_OACC_KERNELS:
      start_ix = BUILT_IN_GOACC_PARALLEL;
      break;
    case GF_OMP_TARGET_KIND_OACC_DATA:
      start_ix = BUILT_IN_GOACC_DATA_START;
      break;
    case GF_OMP_TARGET_KIND_OACC_UPDATE:
      start_ix = BUILT_IN_GOACC_UPDATE;
      break;
    case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA:
      start_ix = BUILT_IN_GOACC_ENTER_EXIT_DATA;
      break;
    default:
      gcc_unreachable ();
    }

  clauses = gimple_omp_target_clauses (entry_stmt);

  /* By default, the value of DEVICE is GOMP_DEVICE_ICV (let runtime
     library choose) and there is no conditional.  */
  cond = NULL_TREE;
  device = build_int_cst (integer_type_node, GOMP_DEVICE_ICV);

  c = find_omp_clause (clauses, OMP_CLAUSE_IF);
  if (c)
    cond = OMP_CLAUSE_IF_EXPR (c);

  c = find_omp_clause (clauses, OMP_CLAUSE_DEVICE);
  if (c)
    {
      /* Even if we pass it to all library function calls, it is currently only
         defined/used for the OpenMP target ones.  */
      gcc_checking_assert (start_ix == BUILT_IN_GOMP_TARGET
                           || start_ix == BUILT_IN_GOMP_TARGET_DATA
                           || start_ix == BUILT_IN_GOMP_TARGET_UPDATE);

      device = OMP_CLAUSE_DEVICE_ID (c);
      clause_loc = OMP_CLAUSE_LOCATION (c);
    }
  else
    clause_loc = gimple_location (entry_stmt);

  /* Ensure 'device' is of the correct type.  */
  device = fold_convert_loc (clause_loc, integer_type_node, device);

  /* If we found the clause 'if (cond)', build
     (cond ? device : GOMP_DEVICE_HOST_FALLBACK).  */
  if (cond)
    {
      cond = gimple_boolify (cond);

      basic_block cond_bb, then_bb, else_bb;
      edge e;
      tree tmp_var;

      tmp_var = create_tmp_var (TREE_TYPE (device));
      if (offloaded)
        e = split_block_after_labels (new_bb);
      else
        {
          gsi = gsi_last_bb (new_bb);
          gsi_prev (&gsi);
          e = split_block (new_bb, gsi_stmt (gsi));
        }
      cond_bb = e->src;
      new_bb = e->dest;
      remove_edge (e);

      then_bb = create_empty_bb (cond_bb);
      else_bb = create_empty_bb (then_bb);
      set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb);
      set_immediate_dominator (CDI_DOMINATORS, else_bb, cond_bb);

      stmt = gimple_build_cond_empty (cond);
      gsi = gsi_last_bb (cond_bb);
      gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

      gsi = gsi_start_bb (then_bb);
      stmt = gimple_build_assign (tmp_var, device);
      gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

      gsi = gsi_start_bb (else_bb);
      stmt = gimple_build_assign (tmp_var,
                                  build_int_cst (integer_type_node,
                                                 GOMP_DEVICE_HOST_FALLBACK));
      gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);

      make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE);
      make_edge (cond_bb, else_bb, EDGE_FALSE_VALUE);
      add_bb_to_loop (then_bb, cond_bb->loop_father);
      add_bb_to_loop (else_bb, cond_bb->loop_father);
      make_edge (then_bb, new_bb, EDGE_FALLTHRU);
      make_edge (else_bb, new_bb, EDGE_FALLTHRU);

      device = tmp_var;
    }

  gsi = gsi_last_bb (new_bb);
  t = gimple_omp_target_data_arg (entry_stmt);
  if (t == NULL)
    {
      t1 = size_zero_node;
      t2 = build_zero_cst (ptr_type_node);
      t3 = t2;
      t4 = t2;
    }
  else
    {
      t1 = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (TREE_VEC_ELT (t, 1))));
      t1 = size_binop (PLUS_EXPR, t1, size_int (1));
      t2 = build_fold_addr_expr (TREE_VEC_ELT (t, 0));
      t3 = build_fold_addr_expr (TREE_VEC_ELT (t, 1));
      t4 = build_fold_addr_expr (TREE_VEC_ELT (t, 2));
    }

  gimple g;
  /* The maximum number used by any start_ix, without varargs.  */
  auto_vec<tree, 11> args;
  args.quick_push (device);
  if (offloaded)
    args.quick_push (build_fold_addr_expr (child_fn));
  switch (start_ix)
    {
    case BUILT_IN_GOMP_TARGET:
    case BUILT_IN_GOMP_TARGET_DATA:
    case BUILT_IN_GOMP_TARGET_UPDATE:
      /* This const void * is part of the current ABI, but we're not actually
         using it.  */
      args.quick_push (build_zero_cst (ptr_type_node));
      break;
    case BUILT_IN_GOACC_DATA_START:
    case BUILT_IN_GOACC_ENTER_EXIT_DATA:
    case BUILT_IN_GOACC_PARALLEL:
    case BUILT_IN_GOACC_UPDATE:
      break;
    default:
      gcc_unreachable ();
    }
  args.quick_push (t1);
  args.quick_push (t2);
  args.quick_push (t3);
  args.quick_push (t4);
  switch (start_ix)
    {
    case BUILT_IN_GOACC_DATA_START:
    case BUILT_IN_GOMP_TARGET:
    case BUILT_IN_GOMP_TARGET_DATA:
    case BUILT_IN_GOMP_TARGET_UPDATE:
      break;
    case BUILT_IN_GOACC_PARALLEL:
      {
        tree t_num_gangs, t_num_workers, t_vector_length;

        /* Default values for num_gangs, num_workers, and vector_length.  */
        t_num_gangs = t_num_workers = t_vector_length
          = fold_convert_loc (gimple_location (entry_stmt),
                              integer_type_node, integer_one_node);
        /* ..., but if present, use the value specified by the respective
           clause, making sure that are of the correct type.  */
        c = find_omp_clause (clauses, OMP_CLAUSE_NUM_GANGS);
        if (c)
          t_num_gangs = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
                                          integer_type_node,
                                          OMP_CLAUSE_NUM_GANGS_EXPR (c));
        c = find_omp_clause (clauses, OMP_CLAUSE_NUM_WORKERS);
        if (c)
          t_num_workers = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
                                            integer_type_node,
                                            OMP_CLAUSE_NUM_WORKERS_EXPR (c));
        c = find_omp_clause (clauses, OMP_CLAUSE_VECTOR_LENGTH);
        if (c)
          t_vector_length = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
                                              integer_type_node,
                                              OMP_CLAUSE_VECTOR_LENGTH_EXPR (c));
        args.quick_push (t_num_gangs);
        args.quick_push (t_num_workers);
        args.quick_push (t_vector_length);
      }
      /* FALLTHRU */
    case BUILT_IN_GOACC_ENTER_EXIT_DATA:
    case BUILT_IN_GOACC_UPDATE:
      {
        tree t_async;
        int t_wait_idx;

        /* Default values for t_async.  */
        t_async = fold_convert_loc (gimple_location (entry_stmt),
                                    integer_type_node,
                                    build_int_cst (integer_type_node,
                                                   GOMP_ASYNC_SYNC));
        /* ..., but if present, use the value specified by the respective
           clause, making sure that is of the correct type.  */
        c = find_omp_clause (clauses, OMP_CLAUSE_ASYNC);
        if (c)
          t_async = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
                                      integer_type_node,
                                      OMP_CLAUSE_ASYNC_EXPR (c));

        args.quick_push (t_async);
        /* Save the index, and... */
        t_wait_idx = args.length ();
        /* ... push a default value.  */
        args.quick_push (fold_convert_loc (gimple_location (entry_stmt),
                                           integer_type_node,
                                           integer_zero_node));
        c = find_omp_clause (clauses, OMP_CLAUSE_WAIT);
        if (c)
          {
            int n = 0;

            for (; c; c = OMP_CLAUSE_CHAIN (c))
              {
                if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_WAIT)
                  {
                    args.safe_push (fold_convert_loc (OMP_CLAUSE_LOCATION (c),
                                                      integer_type_node,
                                                      OMP_CLAUSE_WAIT_EXPR (c)));
                    n++;
                  }
              }

            /* Now that we know the number, replace the default value.  */
            args.ordered_remove (t_wait_idx);
            args.quick_insert (t_wait_idx,
                               fold_convert_loc (gimple_location (entry_stmt),
                                                 integer_type_node,
                                                 build_int_cst (integer_type_node, n)));
          }
      }
      break;
    default:
      gcc_unreachable ();
    }

  g = gimple_build_call_vec (builtin_decl_explicit (start_ix), args);
  gimple_set_location (g, gimple_location (entry_stmt));
  gsi_insert_before (&gsi, g, GSI_SAME_STMT);
  if (!offloaded)
    {
      g = gsi_stmt (gsi);
      gcc_assert (g && gimple_code (g) == GIMPLE_OMP_TARGET);
      gsi_remove (&gsi, true);
    }
  if (data_region
      && region->exit)
    {
      gsi = gsi_last_bb (region->exit);
      g = gsi_stmt (gsi);
      gcc_assert (g && gimple_code (g) == GIMPLE_OMP_RETURN);
      gsi_remove (&gsi, true);
    }
}


/* Expand the parallel region tree rooted at REGION.  Expansion
   proceeds in depth-first order.  Innermost regions are expanded
   first.  This way, parallel regions that require a new function to
   be created (e.g., GIMPLE_OMP_PARALLEL) can be expanded without having any
   internal dependencies in their body.  */

static void
expand_omp (struct omp_region *region)
{
  while (region)
    {
      location_t saved_location;
      gimple inner_stmt = NULL;

      /* First, determine whether this is a combined parallel+workshare
         region.  */
      if (region->type == GIMPLE_OMP_PARALLEL)
        determine_parallel_type (region);

      if (region->type == GIMPLE_OMP_FOR
          && gimple_omp_for_combined_p (last_stmt (region->entry)))
        inner_stmt = last_stmt (region->inner->entry);

      if (region->inner)
        expand_omp (region->inner);

      saved_location = input_location;
      if (gimple_has_location (last_stmt (region->entry)))
        input_location = gimple_location (last_stmt (region->entry));

      switch (region->type)
        {
        case GIMPLE_OMP_PARALLEL:
        case GIMPLE_OMP_TASK:
          expand_omp_taskreg (region);
          break;

        case GIMPLE_OMP_FOR:
          expand_omp_for (region, inner_stmt);
          break;

        case GIMPLE_OMP_SECTIONS:
          expand_omp_sections (region);
          break;

        case GIMPLE_OMP_SECTION:
          /* Individual omp sections are handled together with their
             parent GIMPLE_OMP_SECTIONS region.  */
          break;

        case GIMPLE_OMP_SINGLE:
          expand_omp_single (region);
          break;

        case GIMPLE_OMP_MASTER:
        case GIMPLE_OMP_TASKGROUP:
        case GIMPLE_OMP_ORDERED:
        case GIMPLE_OMP_CRITICAL:
        case GIMPLE_OMP_TEAMS:
          expand_omp_synch (region);
          break;

        case GIMPLE_OMP_ATOMIC_LOAD:
          expand_omp_atomic (region);
          break;

        case GIMPLE_OMP_TARGET:
          expand_omp_target (region);
          break;

        default:
          gcc_unreachable ();
        }

      input_location = saved_location;
      region = region->next;
    }
}


/* Helper for build_omp_regions.  Scan the dominator tree starting at
   block BB.  PARENT is the region that contains BB.  If SINGLE_TREE is
   true, the function ends once a single tree is built (otherwise, whole
   forest of OMP constructs may be built).  */

static void
build_omp_regions_1 (basic_block bb, struct omp_region *parent,
                     bool single_tree)
{
  gimple_stmt_iterator gsi;
  gimple stmt;
  basic_block son;

  gsi = gsi_last_bb (bb);
  if (!gsi_end_p (gsi) && is_gimple_omp (gsi_stmt (gsi)))
    {
      struct omp_region *region;
      enum gimple_code code;

      stmt = gsi_stmt (gsi);
      code = gimple_code (stmt);
      if (code == GIMPLE_OMP_RETURN)
        {
          /* STMT is the return point out of region PARENT.  Mark it
             as the exit point and make PARENT the immediately
             enclosing region.  */
          gcc_assert (parent);
          region = parent;
          region->exit = bb;
          parent = parent->outer;
        }
      else if (code == GIMPLE_OMP_ATOMIC_STORE)
        {
          /* GIMPLE_OMP_ATOMIC_STORE is analoguous to
             GIMPLE_OMP_RETURN, but matches with
             GIMPLE_OMP_ATOMIC_LOAD.  */
          gcc_assert (parent);
          gcc_assert (parent->type == GIMPLE_OMP_ATOMIC_LOAD);
          region = parent;
          region->exit = bb;
          parent = parent->outer;
        }
      else if (code == GIMPLE_OMP_CONTINUE)
        {
          gcc_assert (parent);
          parent->cont = bb;
        }
      else if (code == GIMPLE_OMP_SECTIONS_SWITCH)
        {
          /* GIMPLE_OMP_SECTIONS_SWITCH is part of
             GIMPLE_OMP_SECTIONS, and we do nothing for it.  */
        }
      else
        {
          region = new_omp_region (bb, code, parent);
          /* Otherwise...  */
          if (code == GIMPLE_OMP_TARGET)
            {
              switch (gimple_omp_target_kind (stmt))
                {
                case GF_OMP_TARGET_KIND_REGION:
                case GF_OMP_TARGET_KIND_DATA:
                case GF_OMP_TARGET_KIND_OACC_PARALLEL:
                case GF_OMP_TARGET_KIND_OACC_KERNELS:
                case GF_OMP_TARGET_KIND_OACC_DATA:
                  break;
                case GF_OMP_TARGET_KIND_UPDATE:
                case GF_OMP_TARGET_KIND_OACC_UPDATE:
                case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA:
                  /* ..., other than for those stand-alone directives...  */
                  region = NULL;
                  break;
                default:
                  gcc_unreachable ();
                }
            }
          /* ..., this directive becomes the parent for a new region.  */
          if (region)
            parent = region;
        }
    }

  if (single_tree && !parent)
    return;

  for (son = first_dom_son (CDI_DOMINATORS, bb);
       son;
       son = next_dom_son (CDI_DOMINATORS, son))
    build_omp_regions_1 (son, parent, single_tree);
}

/* Builds the tree of OMP regions rooted at ROOT, storing it to
   root_omp_region.  */

static void
build_omp_regions_root (basic_block root)
{
  gcc_assert (root_omp_region == NULL);
  build_omp_regions_1 (root, NULL, true);
  gcc_assert (root_omp_region != NULL);
}

/* Expands omp construct (and its subconstructs) starting in HEAD.  */

void
omp_expand_local (basic_block head)
{
  build_omp_regions_root (head);
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\nOMP region tree\n\n");
      dump_omp_region (dump_file, root_omp_region, 0);
      fprintf (dump_file, "\n");
    }

  remove_exit_barriers (root_omp_region);
  expand_omp (root_omp_region);

  free_omp_regions ();
}

/* Scan the CFG and build a tree of OMP regions.  Return the root of
   the OMP region tree.  */

static void
build_omp_regions (void)
{
  gcc_assert (root_omp_region == NULL);
  calculate_dominance_info (CDI_DOMINATORS);
  build_omp_regions_1 (ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, false);
}

/* Main entry point for expanding OMP-GIMPLE into runtime calls.  */

static unsigned int
execute_expand_omp (void)
{
  build_omp_regions ();

  if (!root_omp_region)
    return 0;

  if (dump_file)
    {
      fprintf (dump_file, "\nOMP region tree\n\n");
      dump_omp_region (dump_file, root_omp_region, 0);
      fprintf (dump_file, "\n");
    }

  remove_exit_barriers (root_omp_region);

  expand_omp (root_omp_region);

#ifdef ENABLE_CHECKING
  if (!loops_state_satisfies_p (LOOPS_NEED_FIXUP))
    verify_loop_structure ();
#endif
  cleanup_tree_cfg ();

  free_omp_regions ();

  return 0;
}

/* OMP expansion -- the default pass, run before creation of SSA form.  */

namespace {

const pass_data pass_data_expand_omp =
{
  GIMPLE_PASS, /* type */
  "ompexp", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  PROP_gimple_any, /* properties_required */
  PROP_gimple_eomp, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_expand_omp : public gimple_opt_pass
{
public:
  pass_expand_omp (gcc::context *ctxt)
    : gimple_opt_pass (pass_data_expand_omp, ctxt)
  {}

  /* opt_pass methods: */
  virtual unsigned int execute (function *)
    {
      bool gate = ((flag_cilkplus != 0 || flag_openacc != 0 || flag_openmp != 0
                    || flag_openmp_simd != 0)
                   && !seen_error ());

      /* This pass always runs, to provide PROP_gimple_eomp.
         But often, there is nothing to do.  */
      if (!gate)
        return 0;

      return execute_expand_omp ();
    }

}; // class pass_expand_omp

} // anon namespace

gimple_opt_pass *
make_pass_expand_omp (gcc::context *ctxt)
{
  return new pass_expand_omp (ctxt);
}

namespace {

const pass_data pass_data_expand_omp_ssa =
{
  GIMPLE_PASS, /* type */
  "ompexpssa", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  PROP_cfg | PROP_ssa, /* properties_required */
  PROP_gimple_eomp, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  TODO_cleanup_cfg | TODO_rebuild_alias, /* todo_flags_finish */
};

class pass_expand_omp_ssa : public gimple_opt_pass
{
public:
  pass_expand_omp_ssa (gcc::context *ctxt)
    : gimple_opt_pass (pass_data_expand_omp_ssa, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *fun)
    {
      return !(fun->curr_properties & PROP_gimple_eomp);
    }
  virtual unsigned int execute (function *) { return execute_expand_omp (); }

}; // class pass_expand_omp_ssa

} // anon namespace

gimple_opt_pass *
make_pass_expand_omp_ssa (gcc::context *ctxt)
{
  return new pass_expand_omp_ssa (ctxt);
}
\f
/* Routines to lower OMP directives into OMP-GIMPLE.  */

/* Helper function to preform, potentially COMPLEX_TYPE, operation and
   convert it to gimple.  */
static void
oacc_gimple_assign (tree dest, tree_code op, tree src, gimple_seq *seq)
{
  gimple stmt;

  if (TREE_CODE (TREE_TYPE (dest)) != COMPLEX_TYPE)
    {
      stmt = gimple_build_assign (dest, op, dest, src);
      gimple_seq_add_stmt (seq, stmt);
      return;
    }

  tree t = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
  tree rdest = fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (dest)), dest);
  gimplify_assign (t, rdest, seq);
  rdest = t;

  t = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
  tree idest = fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (dest)), dest);
  gimplify_assign (t, idest, seq);
  idest = t;

  t = create_tmp_var (TREE_TYPE (TREE_TYPE (src)));
  tree rsrc = fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (src)), src);
  gimplify_assign (t, rsrc, seq);
  rsrc = t;

  t = create_tmp_var (TREE_TYPE (TREE_TYPE (src)));
  tree isrc = fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (src)), src);
  gimplify_assign (t, isrc, seq);
  isrc = t;

  tree r = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
  tree i = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
  tree result;

  if (op == PLUS_EXPR)
    {
      stmt = gimple_build_assign (r, op, rdest, rsrc);
      gimple_seq_add_stmt (seq, stmt);

      stmt = gimple_build_assign (i, op, idest, isrc);
      gimple_seq_add_stmt (seq, stmt);
    }
  else if (op == MULT_EXPR)
    {
      /* Let x = a + ib = dest, y = c + id = src.
         x * y = (ac - bd) + i(ad + bc)  */
      tree ac = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
      tree bd = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
      tree ad = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));
      tree bc = create_tmp_var (TREE_TYPE (TREE_TYPE (dest)));

      stmt = gimple_build_assign (ac, MULT_EXPR, rdest, rsrc);
      gimple_seq_add_stmt (seq, stmt);

      stmt = gimple_build_assign (bd, MULT_EXPR, idest, isrc);
      gimple_seq_add_stmt (seq, stmt);

      stmt = gimple_build_assign (r, MINUS_EXPR, ac, bd);
      gimple_seq_add_stmt (seq, stmt);

      stmt = gimple_build_assign (ad, MULT_EXPR, rdest, isrc);
      gimple_seq_add_stmt (seq, stmt);

      stmt = gimple_build_assign (bd, MULT_EXPR, idest, rsrc);
      gimple_seq_add_stmt (seq, stmt);

      stmt = gimple_build_assign (i, PLUS_EXPR, ad, bc);
      gimple_seq_add_stmt (seq, stmt);
    }
  else
    gcc_unreachable ();

  result = build2 (COMPLEX_EXPR, TREE_TYPE (dest), r, i);
  gimplify_assign (dest, result, seq);
}

/* Helper function to initialize local data for the reduction arrays.
   The reduction arrays need to be placed inside the calling function
   for accelerators, or else the host won't be able to preform the final
   reduction.  */

static void
oacc_initialize_reduction_data (tree clauses, tree nthreads,
                                gimple_seq *stmt_seqp, omp_context *ctx)
{
  tree c, t, oc;
  gimple stmt;
  omp_context *octx;

  /* Find the innermost OpenACC parallel context.  */
  if (gimple_code (ctx->stmt) == GIMPLE_OMP_TARGET
      && (gimple_omp_target_kind (ctx->stmt)
          == GF_OMP_TARGET_KIND_OACC_PARALLEL))
    octx = ctx;
  else
    octx = ctx->outer;
  gcc_checking_assert (gimple_code (octx->stmt) == GIMPLE_OMP_TARGET
                       && (gimple_omp_target_kind (octx->stmt)
                           == GF_OMP_TARGET_KIND_OACC_PARALLEL));

  /* Extract the clauses.  */
  oc = gimple_omp_target_clauses (octx->stmt);

  /* Find the last outer clause.  */
  for (; oc && OMP_CLAUSE_CHAIN (oc); oc = OMP_CLAUSE_CHAIN (oc))
    ;

  /* Allocate arrays for each reduction variable.  */
  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
    {
      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_REDUCTION)
        continue;

      tree var = OMP_CLAUSE_DECL (c);
      tree type = get_base_type (var);
      tree array = lookup_oacc_reduction (oacc_get_reduction_array_id (var),
                                          ctx);
      tree size, call;

      /* Calculate size of the reduction array.  */
      t = create_tmp_var (TREE_TYPE (nthreads));
      stmt = gimple_build_assign (t, MULT_EXPR, nthreads,
                                  fold_convert (TREE_TYPE (nthreads),
                                                TYPE_SIZE_UNIT (type)));
      gimple_seq_add_stmt (stmt_seqp, stmt);

      size = create_tmp_var (sizetype);
      gimplify_assign (size, fold_build1 (NOP_EXPR, sizetype, t), stmt_seqp);

      /* Now allocate memory for it.  */
      call = unshare_expr (builtin_decl_explicit (BUILT_IN_ALLOCA));
      stmt = gimple_build_call (call, 1, size);
      gimple_call_set_lhs (stmt, array);
      gimple_seq_add_stmt (stmt_seqp, stmt);

      /* Map this array into the accelerator.  */

      /* Add the reduction array to the list of clauses.  */
      tree x = array;
      t = build_omp_clause (gimple_location (ctx->stmt), OMP_CLAUSE_MAP);
      OMP_CLAUSE_SET_MAP_KIND (t, GOMP_MAP_FORCE_FROM);
      OMP_CLAUSE_DECL (t) = x;
      OMP_CLAUSE_CHAIN (t) = NULL;
      if (oc)
        OMP_CLAUSE_CHAIN (oc) = t;
      else
        gimple_omp_target_set_clauses (as_a <gomp_target *> (octx->stmt), t);
      OMP_CLAUSE_SIZE (t) = size;
      oc = t;
    }
}

/* Helper function to process the array of partial reductions.  Nthreads
   indicates the number of threads.  Unfortunately, GOACC_GET_NUM_THREADS
   cannot be used here, because nthreads on the host may be different than
   on the accelerator. */

static void
oacc_finalize_reduction_data (tree clauses, tree nthreads,
                              gimple_seq *stmt_seqp, omp_context *ctx)
{
  tree c, x, var, array, loop_header, loop_body, loop_exit, type;
  gimple stmt;

  /* Create for loop.

     let var = the original reduction variable
     let array = reduction variable array

     for (i = 0; i < nthreads; i++)
       var op= array[i]
 */

  loop_header = create_artificial_label (UNKNOWN_LOCATION);
  loop_body = create_artificial_label (UNKNOWN_LOCATION);
  loop_exit = create_artificial_label (UNKNOWN_LOCATION);

  /* Create and initialize an index variable.  */
  tree ix = create_tmp_var (sizetype);
  gimplify_assign (ix, fold_build1 (NOP_EXPR, sizetype, integer_zero_node),
                   stmt_seqp);

  /* Insert the loop header label here.  */
  gimple_seq_add_stmt (stmt_seqp, gimple_build_label (loop_header));

  /* Exit loop if ix >= nthreads.  */
  x = create_tmp_var (sizetype);
  gimplify_assign (x, fold_build1 (NOP_EXPR, sizetype, nthreads), stmt_seqp);
  stmt = gimple_build_cond (GE_EXPR, ix, x, loop_exit, loop_body);
  gimple_seq_add_stmt (stmt_seqp, stmt);

  /* Insert the loop body label here.  */
  gimple_seq_add_stmt (stmt_seqp, gimple_build_label (loop_body));

  /* Collapse each reduction array, one element at a time.  */
  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
    {
      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_REDUCTION)
        continue;

      tree_code reduction_code = OMP_CLAUSE_REDUCTION_CODE (c);

      /* reduction(-:var) sums up the partial results, so it acts
         identically to reduction(+:var).  */
      if (reduction_code == MINUS_EXPR)
        reduction_code = PLUS_EXPR;

      /* Set up reduction variable var.  */
      var = OMP_CLAUSE_DECL (c);
      type = get_base_type (var);
      array = lookup_oacc_reduction (oacc_get_reduction_array_id
                                     (OMP_CLAUSE_DECL (c)), ctx);

      /* Calculate the array offset.  */
      tree offset = create_tmp_var (sizetype);
      gimplify_assign (offset, TYPE_SIZE_UNIT (type), stmt_seqp);
      stmt = gimple_build_assign (offset, MULT_EXPR, offset, ix);
      gimple_seq_add_stmt (stmt_seqp, stmt);

      tree ptr = create_tmp_var (TREE_TYPE (array));
      stmt = gimple_build_assign (ptr, POINTER_PLUS_EXPR, array, offset);
      gimple_seq_add_stmt (stmt_seqp, stmt);

      /* Extract array[ix] into mem.  */
      tree mem = create_tmp_var (type);
      gimplify_assign (mem, build_simple_mem_ref (ptr), stmt_seqp);

      /* Find the original reduction variable.  */
      if (is_reference (var))
        var = build_simple_mem_ref (var);

      tree t = create_tmp_var (type);

      x = lang_hooks.decls.omp_clause_assign_op (c, t, var);
      gimplify_and_add (unshare_expr(x), stmt_seqp);

      /* var = var op mem */
      switch (OMP_CLAUSE_REDUCTION_CODE (c))
        {
        case TRUTH_ANDIF_EXPR:
        case TRUTH_ORIF_EXPR:
          t = fold_build2 (OMP_CLAUSE_REDUCTION_CODE (c), integer_type_node,
                           t, mem);
          gimplify_and_add (t, stmt_seqp);
          break;
        default:
          /* The lhs isn't a gimple_reg when var is COMPLEX_TYPE.  */
          oacc_gimple_assign (t, OMP_CLAUSE_REDUCTION_CODE (c), mem,
                              stmt_seqp);
        }

      t = fold_build1 (NOP_EXPR, TREE_TYPE (var), t);
      x = lang_hooks.decls.omp_clause_assign_op (c, var, t);
      gimplify_and_add (unshare_expr(x), stmt_seqp);
    }

  /* Increment the induction variable.  */
  tree one = fold_build1 (NOP_EXPR, sizetype, integer_one_node);
  stmt = gimple_build_assign (ix, PLUS_EXPR, ix, one);
  gimple_seq_add_stmt (stmt_seqp, stmt);

  /* Go back to the top of the loop.  */
  gimple_seq_add_stmt (stmt_seqp, gimple_build_goto (loop_header));

  /* Place the loop exit label here.  */
  gimple_seq_add_stmt (stmt_seqp, gimple_build_label (loop_exit));
}

/* Scan through all of the gimple stmts searching for an OMP_FOR_EXPR, and
   scan that for reductions.  */

static void
oacc_process_reduction_data (gimple_seq *body, gimple_seq *in_stmt_seqp,
                        gimple_seq *out_stmt_seqp, omp_context *ctx)
{
  gimple_stmt_iterator gsi;
  gimple_seq inner = NULL;

  /* A collapse clause may have inserted a new bind block.  */
  gsi = gsi_start (*body);
  while (!gsi_end_p (gsi))
    {
      gimple stmt = gsi_stmt (gsi);
      if (gbind *bind_stmt = dyn_cast <gbind *> (stmt))
        {
          inner = gimple_bind_body (bind_stmt);
          body = &inner;
          gsi = gsi_start (*body);
        }
      else if (dyn_cast <gomp_for *> (stmt))
        break;
      else
        gsi_next (&gsi);
    }

  for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
    {
      tree clauses, nthreads, t, c, acc_device, acc_device_host, call,
        enter, exit;
      bool reduction_found = false;

      gimple stmt = gsi_stmt (gsi);

      switch (gimple_code (stmt))
        {
        case GIMPLE_OMP_FOR:
          clauses = gimple_omp_for_clauses (stmt);

          /* Search for a reduction clause.  */
          for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
            if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION)
              {
                reduction_found = true;
                break;
              }

          if (!reduction_found)
            break;

          ctx = maybe_lookup_ctx (stmt);
          t = NULL_TREE;

          /* Extract the number of threads.  */
          nthreads = create_tmp_var (sizetype);
          t = oacc_max_threads (ctx);
          gimplify_assign (nthreads, t, in_stmt_seqp);

          /* Determine if this is kernel will be executed on the host.  */
          call = builtin_decl_explicit (BUILT_IN_ACC_GET_DEVICE_TYPE);
          acc_device = create_tmp_var (integer_type_node, ".acc_device_type");
          stmt = gimple_build_call (call, 0);
          gimple_call_set_lhs (stmt, acc_device);
          gimple_seq_add_stmt (in_stmt_seqp, stmt);

          /* Set nthreads = 1 for ACC_DEVICE_TYPE=host.  */
          acc_device_host = create_tmp_var (integer_type_node,
                                            ".acc_device_host");
          gimplify_assign (acc_device_host,
                           build_int_cst (integer_type_node,
                                          GOMP_DEVICE_HOST),
                           in_stmt_seqp);

          enter = create_artificial_label (UNKNOWN_LOCATION);
          exit = create_artificial_label (UNKNOWN_LOCATION);

          stmt = gimple_build_cond (EQ_EXPR, acc_device, acc_device_host,
                                    enter, exit);
          gimple_seq_add_stmt (in_stmt_seqp, stmt);
          gimple_seq_add_stmt (in_stmt_seqp, gimple_build_label (enter));
          gimplify_assign (nthreads, fold_build1 (NOP_EXPR, sizetype,
                                                  integer_one_node),
                           in_stmt_seqp);
          gimple_seq_add_stmt (in_stmt_seqp, gimple_build_label (exit));

          oacc_initialize_reduction_data (clauses, nthreads, in_stmt_seqp,
                                          ctx);
          oacc_finalize_reduction_data (clauses, nthreads, out_stmt_seqp, ctx);
          break;
        default:
          // Scan for other directives which support reduction here.
          break;
        }
    }
}

/* If ctx is a worksharing context inside of a cancellable parallel
   region and it isn't nowait, add lhs to its GIMPLE_OMP_RETURN
   and conditional branch to parallel's cancel_label to handle
   cancellation in the implicit barrier.  */

static void
maybe_add_implicit_barrier_cancel (omp_context *ctx, gimple_seq *body)
{
  gimple omp_return = gimple_seq_last_stmt (*body);
  gcc_assert (gimple_code (omp_return) == GIMPLE_OMP_RETURN);
  if (gimple_omp_return_nowait_p (omp_return))
    return;
  if (ctx->outer
      && gimple_code (ctx->outer->stmt) == GIMPLE_OMP_PARALLEL
      && ctx->outer->cancellable)
    {
      tree fndecl = builtin_decl_explicit (BUILT_IN_GOMP_CANCEL);
      tree c_bool_type = TREE_TYPE (TREE_TYPE (fndecl));
      tree lhs = create_tmp_var (c_bool_type);
      gimple_omp_return_set_lhs (omp_return, lhs);
      tree fallthru_label = create_artificial_label (UNKNOWN_LOCATION);
      gimple g = gimple_build_cond (NE_EXPR, lhs,
                                    fold_convert (c_bool_type,
                                                  boolean_false_node),
                                    ctx->outer->cancel_label, fallthru_label);
      gimple_seq_add_stmt (body, g);
      gimple_seq_add_stmt (body, gimple_build_label (fallthru_label));
    }
}

/* Lower the OpenMP sections directive in the current statement in GSI_P.
   CTX is the enclosing OMP context for the current statement.  */

static void
lower_omp_sections (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree block, control;
  gimple_stmt_iterator tgsi;
  gomp_sections *stmt;
  gimple t;
  gbind *new_stmt, *bind;
  gimple_seq ilist, dlist, olist, new_body;

  stmt = as_a <gomp_sections *> (gsi_stmt (*gsi_p));

  push_gimplify_context ();

  dlist = NULL;
  ilist = NULL;
  lower_rec_input_clauses (gimple_omp_sections_clauses (stmt),
                           &ilist, &dlist, ctx, NULL);

  new_body = gimple_omp_body (stmt);
  gimple_omp_set_body (stmt, NULL);
  tgsi = gsi_start (new_body);
  for (; !gsi_end_p (tgsi); gsi_next (&tgsi))
    {
      omp_context *sctx;
      gimple sec_start;

      sec_start = gsi_stmt (tgsi);
      sctx = maybe_lookup_ctx (sec_start);
      gcc_assert (sctx);

      lower_omp (gimple_omp_body_ptr (sec_start), sctx);
      gsi_insert_seq_after (&tgsi, gimple_omp_body (sec_start),
                            GSI_CONTINUE_LINKING);
      gimple_omp_set_body (sec_start, NULL);

      if (gsi_one_before_end_p (tgsi))
        {
          gimple_seq l = NULL;
          lower_lastprivate_clauses (gimple_omp_sections_clauses (stmt), NULL,
                                     &l, ctx);
          gsi_insert_seq_after (&tgsi, l, GSI_CONTINUE_LINKING);
          gimple_omp_section_set_last (sec_start);
        }

      gsi_insert_after (&tgsi, gimple_build_omp_return (false),
                        GSI_CONTINUE_LINKING);
    }

  block = make_node (BLOCK);
  bind = gimple_build_bind (NULL, new_body, block);

  olist = NULL;
  lower_reduction_clauses (gimple_omp_sections_clauses (stmt), &olist, ctx);

  block = make_node (BLOCK);
  new_stmt = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, new_stmt, true);

  pop_gimplify_context (new_stmt);
  gimple_bind_append_vars (new_stmt, ctx->block_vars);
  BLOCK_VARS (block) = gimple_bind_vars (bind);
  if (BLOCK_VARS (block))
    TREE_USED (block) = 1;

  new_body = NULL;
  gimple_seq_add_seq (&new_body, ilist);
  gimple_seq_add_stmt (&new_body, stmt);
  gimple_seq_add_stmt (&new_body, gimple_build_omp_sections_switch ());
  gimple_seq_add_stmt (&new_body, bind);

  control = create_tmp_var (unsigned_type_node, ".section");
  t = gimple_build_omp_continue (control, control);
  gimple_omp_sections_set_control (stmt, control);
  gimple_seq_add_stmt (&new_body, t);

  gimple_seq_add_seq (&new_body, olist);
  if (ctx->cancellable)
    gimple_seq_add_stmt (&new_body, gimple_build_label (ctx->cancel_label));
  gimple_seq_add_seq (&new_body, dlist);

  new_body = maybe_catch_exception (new_body);

  t = gimple_build_omp_return
        (!!find_omp_clause (gimple_omp_sections_clauses (stmt),
                            OMP_CLAUSE_NOWAIT));
  gimple_seq_add_stmt (&new_body, t);
  maybe_add_implicit_barrier_cancel (ctx, &new_body);

  gimple_bind_set_body (new_stmt, new_body);
}


/* A subroutine of lower_omp_single.  Expand the simple form of
   a GIMPLE_OMP_SINGLE, without a copyprivate clause:

        if (GOMP_single_start ())
          BODY;
        [ GOMP_barrier (); ]    -> unless 'nowait' is present.

  FIXME.  It may be better to delay expanding the logic of this until
  pass_expand_omp.  The expanded logic may make the job more difficult
  to a synchronization analysis pass.  */

static void
lower_omp_single_simple (gomp_single *single_stmt, gimple_seq *pre_p)
{
  location_t loc = gimple_location (single_stmt);
  tree tlabel = create_artificial_label (loc);
  tree flabel = create_artificial_label (loc);
  gimple call, cond;
  tree lhs, decl;

  decl = builtin_decl_explicit (BUILT_IN_GOMP_SINGLE_START);
  lhs = create_tmp_var (TREE_TYPE (TREE_TYPE (decl)));
  call = gimple_build_call (decl, 0);
  gimple_call_set_lhs (call, lhs);
  gimple_seq_add_stmt (pre_p, call);

  cond = gimple_build_cond (EQ_EXPR, lhs,
                            fold_convert_loc (loc, TREE_TYPE (lhs),
                                              boolean_true_node),
                            tlabel, flabel);
  gimple_seq_add_stmt (pre_p, cond);
  gimple_seq_add_stmt (pre_p, gimple_build_label (tlabel));
  gimple_seq_add_seq (pre_p, gimple_omp_body (single_stmt));
  gimple_seq_add_stmt (pre_p, gimple_build_label (flabel));
}


/* A subroutine of lower_omp_single.  Expand the simple form of
   a GIMPLE_OMP_SINGLE, with a copyprivate clause:

        #pragma omp single copyprivate (a, b, c)

   Create a new structure to hold copies of 'a', 'b' and 'c' and emit:

      {
        if ((copyout_p = GOMP_single_copy_start ()) == NULL)
          {
            BODY;
            copyout.a = a;
            copyout.b = b;
            copyout.c = c;
            GOMP_single_copy_end (&copyout);
          }
        else
          {
            a = copyout_p->a;
            b = copyout_p->b;
            c = copyout_p->c;
          }
        GOMP_barrier ();
      }

  FIXME.  It may be better to delay expanding the logic of this until
  pass_expand_omp.  The expanded logic may make the job more difficult
  to a synchronization analysis pass.  */

static void
lower_omp_single_copy (gomp_single *single_stmt, gimple_seq *pre_p,
                       omp_context *ctx)
{
  tree ptr_type, t, l0, l1, l2, bfn_decl;
  gimple_seq copyin_seq;
  location_t loc = gimple_location (single_stmt);

  ctx->sender_decl = create_tmp_var (ctx->record_type, ".omp_copy_o");

  ptr_type = build_pointer_type (ctx->record_type);
  ctx->receiver_decl = create_tmp_var (ptr_type, ".omp_copy_i");

  l0 = create_artificial_label (loc);
  l1 = create_artificial_label (loc);
  l2 = create_artificial_label (loc);

  bfn_decl = builtin_decl_explicit (BUILT_IN_GOMP_SINGLE_COPY_START);
  t = build_call_expr_loc (loc, bfn_decl, 0);
  t = fold_convert_loc (loc, ptr_type, t);
  gimplify_assign (ctx->receiver_decl, t, pre_p);

  t = build2 (EQ_EXPR, boolean_type_node, ctx->receiver_decl,
              build_int_cst (ptr_type, 0));
  t = build3 (COND_EXPR, void_type_node, t,
              build_and_jump (&l0), build_and_jump (&l1));
  gimplify_and_add (t, pre_p);

  gimple_seq_add_stmt (pre_p, gimple_build_label (l0));

  gimple_seq_add_seq (pre_p, gimple_omp_body (single_stmt));

  copyin_seq = NULL;
  lower_copyprivate_clauses (gimple_omp_single_clauses (single_stmt), pre_p,
                              &copyin_seq, ctx);

  t = build_fold_addr_expr_loc (loc, ctx->sender_decl);
  bfn_decl = builtin_decl_explicit (BUILT_IN_GOMP_SINGLE_COPY_END);
  t = build_call_expr_loc (loc, bfn_decl, 1, t);
  gimplify_and_add (t, pre_p);

  t = build_and_jump (&l2);
  gimplify_and_add (t, pre_p);

  gimple_seq_add_stmt (pre_p, gimple_build_label (l1));

  gimple_seq_add_seq (pre_p, copyin_seq);

  gimple_seq_add_stmt (pre_p, gimple_build_label (l2));
}


/* Expand code for an OpenMP single directive.  */

static void
lower_omp_single (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree block;
  gimple t;
  gomp_single *single_stmt = as_a <gomp_single *> (gsi_stmt (*gsi_p));
  gbind *bind;
  gimple_seq bind_body, bind_body_tail = NULL, dlist;

  push_gimplify_context ();

  block = make_node (BLOCK);
  bind = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, bind, true);
  bind_body = NULL;
  dlist = NULL;
  lower_rec_input_clauses (gimple_omp_single_clauses (single_stmt),
                           &bind_body, &dlist, ctx, NULL);
  lower_omp (gimple_omp_body_ptr (single_stmt), ctx);

  gimple_seq_add_stmt (&bind_body, single_stmt);

  if (ctx->record_type)
    lower_omp_single_copy (single_stmt, &bind_body, ctx);
  else
    lower_omp_single_simple (single_stmt, &bind_body);

  gimple_omp_set_body (single_stmt, NULL);

  gimple_seq_add_seq (&bind_body, dlist);

  bind_body = maybe_catch_exception (bind_body);

  t = gimple_build_omp_return
        (!!find_omp_clause (gimple_omp_single_clauses (single_stmt),
                            OMP_CLAUSE_NOWAIT));
  gimple_seq_add_stmt (&bind_body_tail, t);
  maybe_add_implicit_barrier_cancel (ctx, &bind_body_tail);
  if (ctx->record_type)
    {
      gimple_stmt_iterator gsi = gsi_start (bind_body_tail);
      tree clobber = build_constructor (ctx->record_type, NULL);
      TREE_THIS_VOLATILE (clobber) = 1;
      gsi_insert_after (&gsi, gimple_build_assign (ctx->sender_decl,
                                                   clobber), GSI_SAME_STMT);
    }
  gimple_seq_add_seq (&bind_body, bind_body_tail);
  gimple_bind_set_body (bind, bind_body);

  pop_gimplify_context (bind);

  gimple_bind_append_vars (bind, ctx->block_vars);
  BLOCK_VARS (block) = ctx->block_vars;
  if (BLOCK_VARS (block))
    TREE_USED (block) = 1;
}


/* Expand code for an OpenMP master directive.  */

static void
lower_omp_master (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree block, lab = NULL, x, bfn_decl;
  gimple stmt = gsi_stmt (*gsi_p);
  gbind *bind;
  location_t loc = gimple_location (stmt);
  gimple_seq tseq;

  push_gimplify_context ();

  block = make_node (BLOCK);
  bind = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, bind, true);
  gimple_bind_add_stmt (bind, stmt);

  bfn_decl = builtin_decl_explicit (BUILT_IN_OMP_GET_THREAD_NUM);
  x = build_call_expr_loc (loc, bfn_decl, 0);
  x = build2 (EQ_EXPR, boolean_type_node, x, integer_zero_node);
  x = build3 (COND_EXPR, void_type_node, x, NULL, build_and_jump (&lab));
  tseq = NULL;
  gimplify_and_add (x, &tseq);
  gimple_bind_add_seq (bind, tseq);

  lower_omp (gimple_omp_body_ptr (stmt), ctx);
  gimple_omp_set_body (stmt, maybe_catch_exception (gimple_omp_body (stmt)));
  gimple_bind_add_seq (bind, gimple_omp_body (stmt));
  gimple_omp_set_body (stmt, NULL);

  gimple_bind_add_stmt (bind, gimple_build_label (lab));

  gimple_bind_add_stmt (bind, gimple_build_omp_return (true));

  pop_gimplify_context (bind);

  gimple_bind_append_vars (bind, ctx->block_vars);
  BLOCK_VARS (block) = ctx->block_vars;
}


/* Expand code for an OpenMP taskgroup directive.  */

static void
lower_omp_taskgroup (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  gimple stmt = gsi_stmt (*gsi_p);
  gcall *x;
  gbind *bind;
  tree block = make_node (BLOCK);

  bind = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, bind, true);
  gimple_bind_add_stmt (bind, stmt);

  x = gimple_build_call (builtin_decl_explicit (BUILT_IN_GOMP_TASKGROUP_START),
                         0);
  gimple_bind_add_stmt (bind, x);

  lower_omp (gimple_omp_body_ptr (stmt), ctx);
  gimple_bind_add_seq (bind, gimple_omp_body (stmt));
  gimple_omp_set_body (stmt, NULL);

  gimple_bind_add_stmt (bind, gimple_build_omp_return (true));

  gimple_bind_append_vars (bind, ctx->block_vars);
  BLOCK_VARS (block) = ctx->block_vars;
}


/* Expand code for an OpenMP ordered directive.  */

static void
lower_omp_ordered (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree block;
  gimple stmt = gsi_stmt (*gsi_p);
  gcall *x;
  gbind *bind;

  push_gimplify_context ();

  block = make_node (BLOCK);
  bind = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, bind, true);
  gimple_bind_add_stmt (bind, stmt);

  x = gimple_build_call (builtin_decl_explicit (BUILT_IN_GOMP_ORDERED_START),
                         0);
  gimple_bind_add_stmt (bind, x);

  lower_omp (gimple_omp_body_ptr (stmt), ctx);
  gimple_omp_set_body (stmt, maybe_catch_exception (gimple_omp_body (stmt)));
  gimple_bind_add_seq (bind, gimple_omp_body (stmt));
  gimple_omp_set_body (stmt, NULL);

  x = gimple_build_call (builtin_decl_explicit (BUILT_IN_GOMP_ORDERED_END), 0);
  gimple_bind_add_stmt (bind, x);

  gimple_bind_add_stmt (bind, gimple_build_omp_return (true));

  pop_gimplify_context (bind);

  gimple_bind_append_vars (bind, ctx->block_vars);
  BLOCK_VARS (block) = gimple_bind_vars (bind);
}


/* Gimplify a GIMPLE_OMP_CRITICAL statement.  This is a relatively simple
   substitution of a couple of function calls.  But in the NAMED case,
   requires that languages coordinate a symbol name.  It is therefore
   best put here in common code.  */

static GTY(()) hash_map<tree, tree> *critical_name_mutexes;

static void
lower_omp_critical (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree block;
  tree name, lock, unlock;
  gomp_critical *stmt = as_a <gomp_critical *> (gsi_stmt (*gsi_p));
  gbind *bind;
  location_t loc = gimple_location (stmt);
  gimple_seq tbody;

  name = gimple_omp_critical_name (stmt);
  if (name)
    {
      tree decl;

      if (!critical_name_mutexes)
        critical_name_mutexes = hash_map<tree, tree>::create_ggc (10);

      tree *n = critical_name_mutexes->get (name);
      if (n == NULL)
        {
          char *new_str;

          decl = create_tmp_var_raw (ptr_type_node);

          new_str = ACONCAT ((".gomp_critical_user_",
                              IDENTIFIER_POINTER (name), NULL));
          DECL_NAME (decl) = get_identifier (new_str);
          TREE_PUBLIC (decl) = 1;
          TREE_STATIC (decl) = 1;
          DECL_COMMON (decl) = 1;
          DECL_ARTIFICIAL (decl) = 1;
          DECL_IGNORED_P (decl) = 1;

          varpool_node::finalize_decl (decl);

          critical_name_mutexes->put (name, decl);
        }
      else
        decl = *n;

      /* If '#pragma omp critical' is inside offloaded region or
         inside function marked as offloadable, the symbol must be
         marked as offloadable too.  */
      omp_context *octx;
      if (cgraph_node::get (current_function_decl)->offloadable)
        varpool_node::get_create (decl)->offloadable = 1;
      else
        for (octx = ctx->outer; octx; octx = octx->outer)
          if (is_gimple_omp_offloaded (octx->stmt))
            {
              varpool_node::get_create (decl)->offloadable = 1;
              break;
            }

      lock = builtin_decl_explicit (BUILT_IN_GOMP_CRITICAL_NAME_START);
      lock = build_call_expr_loc (loc, lock, 1, build_fold_addr_expr_loc (loc, decl));

      unlock = builtin_decl_explicit (BUILT_IN_GOMP_CRITICAL_NAME_END);
      unlock = build_call_expr_loc (loc, unlock, 1,
                                build_fold_addr_expr_loc (loc, decl));
    }
  else
    {
      lock = builtin_decl_explicit (BUILT_IN_GOMP_CRITICAL_START);
      lock = build_call_expr_loc (loc, lock, 0);

      unlock = builtin_decl_explicit (BUILT_IN_GOMP_CRITICAL_END);
      unlock = build_call_expr_loc (loc, unlock, 0);
    }

  push_gimplify_context ();

  block = make_node (BLOCK);
  bind = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, bind, true);
  gimple_bind_add_stmt (bind, stmt);

  tbody = gimple_bind_body (bind);
  gimplify_and_add (lock, &tbody);
  gimple_bind_set_body (bind, tbody);

  lower_omp (gimple_omp_body_ptr (stmt), ctx);
  gimple_omp_set_body (stmt, maybe_catch_exception (gimple_omp_body (stmt)));
  gimple_bind_add_seq (bind, gimple_omp_body (stmt));
  gimple_omp_set_body (stmt, NULL);

  tbody = gimple_bind_body (bind);
  gimplify_and_add (unlock, &tbody);
  gimple_bind_set_body (bind, tbody);

  gimple_bind_add_stmt (bind, gimple_build_omp_return (true));

  pop_gimplify_context (bind);
  gimple_bind_append_vars (bind, ctx->block_vars);
  BLOCK_VARS (block) = gimple_bind_vars (bind);
}


/* A subroutine of lower_omp_for.  Generate code to emit the predicate
   for a lastprivate clause.  Given a loop control predicate of (V
   cond N2), we gate the clause on (!(V cond N2)).  The lowered form
   is appended to *DLIST, iterator initialization is appended to
   *BODY_P.  */

static void
lower_omp_for_lastprivate (struct omp_for_data *fd, gimple_seq *body_p,
                           gimple_seq *dlist, struct omp_context *ctx)
{
  tree clauses, cond, vinit;
  enum tree_code cond_code;
  gimple_seq stmts;

  cond_code = fd->loop.cond_code;
  cond_code = cond_code == LT_EXPR ? GE_EXPR : LE_EXPR;

  /* When possible, use a strict equality expression.  This can let VRP
     type optimizations deduce the value and remove a copy.  */
  if (tree_fits_shwi_p (fd->loop.step))
    {
      HOST_WIDE_INT step = tree_to_shwi (fd->loop.step);
      if (step == 1 || step == -1)
        cond_code = EQ_EXPR;
    }

  tree n2 = fd->loop.n2;
  if (fd->collapse > 1
      && TREE_CODE (n2) != INTEGER_CST
      && gimple_omp_for_combined_into_p (fd->for_stmt)
      && gimple_code (ctx->outer->stmt) == GIMPLE_OMP_FOR)
    {
      gomp_for *gfor = as_a <gomp_for *> (ctx->outer->stmt);
      if (gimple_omp_for_kind (gfor) == GF_OMP_FOR_KIND_FOR)
        {
          struct omp_for_data outer_fd;
          extract_omp_for_data (gfor, &outer_fd, NULL);
          n2 = fold_convert (TREE_TYPE (n2), outer_fd.loop.n2);
        }
    }
  cond = build2 (cond_code, boolean_type_node, fd->loop.v, n2);

  clauses = gimple_omp_for_clauses (fd->for_stmt);
  stmts = NULL;
  lower_lastprivate_clauses (clauses, cond, &stmts, ctx);
  if (!gimple_seq_empty_p (stmts))
    {
      gimple_seq_add_seq (&stmts, *dlist);
      *dlist = stmts;

      /* Optimize: v = 0; is usually cheaper than v = some_other_constant.  */
      vinit = fd->loop.n1;
      if (cond_code == EQ_EXPR
          && tree_fits_shwi_p (fd->loop.n2)
          && ! integer_zerop (fd->loop.n2))
        vinit = build_int_cst (TREE_TYPE (fd->loop.v), 0);
      else
        vinit = unshare_expr (vinit);

      /* Initialize the iterator variable, so that threads that don't execute
         any iterations don't execute the lastprivate clauses by accident.  */
      gimplify_assign (fd->loop.v, vinit, body_p);
    }
}


/* Lower code for an OMP loop directive.  */

static void
lower_omp_for (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree *rhs_p, block;
  struct omp_for_data fd, *fdp = NULL;
  gomp_for *stmt = as_a <gomp_for *> (gsi_stmt (*gsi_p));
  gbind *new_stmt;
  gimple_seq omp_for_body, body, dlist;
  size_t i;

  push_gimplify_context ();

  lower_omp (gimple_omp_for_pre_body_ptr (stmt), ctx);

  block = make_node (BLOCK);
  new_stmt = gimple_build_bind (NULL, NULL, block);
  /* Replace at gsi right away, so that 'stmt' is no member
     of a sequence anymore as we're going to add to a different
     one below.  */
  gsi_replace (gsi_p, new_stmt, true);

  /* Move declaration of temporaries in the loop body before we make
     it go away.  */
  omp_for_body = gimple_omp_body (stmt);
  if (!gimple_seq_empty_p (omp_for_body)
      && gimple_code (gimple_seq_first_stmt (omp_for_body)) == GIMPLE_BIND)
    {
      gbind *inner_bind
        = as_a <gbind *> (gimple_seq_first_stmt (omp_for_body));
      tree vars = gimple_bind_vars (inner_bind);
      gimple_bind_append_vars (new_stmt, vars);
      /* bind_vars/BLOCK_VARS are being moved to new_stmt/block, don't
         keep them on the inner_bind and it's block.  */
      gimple_bind_set_vars (inner_bind, NULL_TREE);
      if (gimple_bind_block (inner_bind))
        BLOCK_VARS (gimple_bind_block (inner_bind)) = NULL_TREE;
    }

  if (gimple_omp_for_combined_into_p (stmt))
    {
      extract_omp_for_data (stmt, &fd, NULL);
      fdp = &fd;

      /* We need two temporaries with fd.loop.v type (istart/iend)
         and then (fd.collapse - 1) temporaries with the same
         type for count2 ... countN-1 vars if not constant.  */
      size_t count = 2;
      tree type = fd.iter_type;
      if (fd.collapse > 1
          && TREE_CODE (fd.loop.n2) != INTEGER_CST)
        count += fd.collapse - 1;
      bool parallel_for = gimple_omp_for_kind (stmt) == GF_OMP_FOR_KIND_FOR;
      tree outerc = NULL, *pc = gimple_omp_for_clauses_ptr (stmt);
      tree clauses = *pc;
      if (parallel_for)
        outerc
          = find_omp_clause (gimple_omp_parallel_clauses (ctx->outer->stmt),
                             OMP_CLAUSE__LOOPTEMP_);
      for (i = 0; i < count; i++)
        {
          tree temp;
          if (parallel_for)
            {
              gcc_assert (outerc);
              temp = lookup_decl (OMP_CLAUSE_DECL (outerc), ctx->outer);
              outerc = find_omp_clause (OMP_CLAUSE_CHAIN (outerc),
                                        OMP_CLAUSE__LOOPTEMP_);
            }
          else
            {
              temp = create_tmp_var (type);
              insert_decl_map (&ctx->outer->cb, temp, temp);
            }
          *pc = build_omp_clause (UNKNOWN_LOCATION, OMP_CLAUSE__LOOPTEMP_);
          OMP_CLAUSE_DECL (*pc) = temp;
          pc = &OMP_CLAUSE_CHAIN (*pc);
        }
      *pc = clauses;
    }

  /* The pre-body and input clauses go before the lowered GIMPLE_OMP_FOR.  */
  dlist = NULL;
  body = NULL;
  lower_rec_input_clauses (gimple_omp_for_clauses (stmt), &body, &dlist, ctx,
                           fdp);
  gimple_seq_add_seq (&body, gimple_omp_for_pre_body (stmt));

  lower_omp (gimple_omp_body_ptr (stmt), ctx);

  /* Lower the header expressions.  At this point, we can assume that
     the header is of the form:

        #pragma omp for (V = VAL1; V {<|>|<=|>=} VAL2; V = V [+-] VAL3)

     We just need to make sure that VAL1, VAL2 and VAL3 are lowered
     using the .omp_data_s mapping, if needed.  */
  for (i = 0; i < gimple_omp_for_collapse (stmt); i++)
    {
      rhs_p = gimple_omp_for_initial_ptr (stmt, i);
      if (!is_gimple_min_invariant (*rhs_p))
        *rhs_p = get_formal_tmp_var (*rhs_p, &body);

      rhs_p = gimple_omp_for_final_ptr (stmt, i);
      if (!is_gimple_min_invariant (*rhs_p))
        *rhs_p = get_formal_tmp_var (*rhs_p, &body);

      rhs_p = &TREE_OPERAND (gimple_omp_for_incr (stmt, i), 1);
      if (!is_gimple_min_invariant (*rhs_p))
        *rhs_p = get_formal_tmp_var (*rhs_p, &body);
    }

  /* Once lowered, extract the bounds and clauses.  */
  extract_omp_for_data (stmt, &fd, NULL);

  lower_omp_for_lastprivate (&fd, &body, &dlist, ctx);

  gimple_seq_add_stmt (&body, stmt);
  gimple_seq_add_seq (&body, gimple_omp_body (stmt));

  gimple_seq_add_stmt (&body, gimple_build_omp_continue (fd.loop.v,
                                                         fd.loop.v));

  /* After the loop, add exit clauses.  */
  lower_reduction_clauses (gimple_omp_for_clauses (stmt), &body, ctx);

  if (ctx->cancellable)
    gimple_seq_add_stmt (&body, gimple_build_label (ctx->cancel_label));

  gimple_seq_add_seq (&body, dlist);

  body = maybe_catch_exception (body);

  /* Region exit marker goes at the end of the loop body.  */
  gimple_seq_add_stmt (&body, gimple_build_omp_return (fd.have_nowait));
  maybe_add_implicit_barrier_cancel (ctx, &body);
  pop_gimplify_context (new_stmt);

  gimple_bind_append_vars (new_stmt, ctx->block_vars);
  BLOCK_VARS (block) = gimple_bind_vars (new_stmt);
  if (BLOCK_VARS (block))
    TREE_USED (block) = 1;

  gimple_bind_set_body (new_stmt, body);
  gimple_omp_set_body (stmt, NULL);
  gimple_omp_for_set_pre_body (stmt, NULL);
}

/* Callback for walk_stmts.  Check if the current statement only contains
   GIMPLE_OMP_FOR or GIMPLE_OMP_SECTIONS.  */

static tree
check_combined_parallel (gimple_stmt_iterator *gsi_p,
                         bool *handled_ops_p,
                         struct walk_stmt_info *wi)
{
  int *info = (int *) wi->info;
  gimple stmt = gsi_stmt (*gsi_p);

  *handled_ops_p = true;
  switch (gimple_code (stmt))
    {
    WALK_SUBSTMTS;

    case GIMPLE_OMP_FOR:
    case GIMPLE_OMP_SECTIONS:
      *info = *info == 0 ? 1 : -1;
      break;
    default:
      *info = -1;
      break;
    }
  return NULL;
}

struct omp_taskcopy_context
{
  /* This field must be at the beginning, as we do "inheritance": Some
     callback functions for tree-inline.c (e.g., omp_copy_decl)
     receive a copy_body_data pointer that is up-casted to an
     omp_context pointer.  */
  copy_body_data cb;
  omp_context *ctx;
};

static tree
task_copyfn_copy_decl (tree var, copy_body_data *cb)
{
  struct omp_taskcopy_context *tcctx = (struct omp_taskcopy_context *) cb;

  if (splay_tree_lookup (tcctx->ctx->sfield_map, (splay_tree_key) var))
    return create_tmp_var (TREE_TYPE (var));

  return var;
}

static tree
task_copyfn_remap_type (struct omp_taskcopy_context *tcctx, tree orig_type)
{
  tree name, new_fields = NULL, type, f;

  type = lang_hooks.types.make_type (RECORD_TYPE);
  name = DECL_NAME (TYPE_NAME (orig_type));
  name = build_decl (gimple_location (tcctx->ctx->stmt),
                     TYPE_DECL, name, type);
  TYPE_NAME (type) = name;

  for (f = TYPE_FIELDS (orig_type); f ; f = TREE_CHAIN (f))
    {
      tree new_f = copy_node (f);
      DECL_CONTEXT (new_f) = type;
      TREE_TYPE (new_f) = remap_type (TREE_TYPE (f), &tcctx->cb);
      TREE_CHAIN (new_f) = new_fields;
      walk_tree (&DECL_SIZE (new_f), copy_tree_body_r, &tcctx->cb, NULL);
      walk_tree (&DECL_SIZE_UNIT (new_f), copy_tree_body_r, &tcctx->cb, NULL);
      walk_tree (&DECL_FIELD_OFFSET (new_f), copy_tree_body_r,
                 &tcctx->cb, NULL);
      new_fields = new_f;
      tcctx->cb.decl_map->put (f, new_f);
    }
  TYPE_FIELDS (type) = nreverse (new_fields);
  layout_type (type);
  return type;
}

/* Create task copyfn.  */

static void
create_task_copyfn (gomp_task *task_stmt, omp_context *ctx)
{
  struct function *child_cfun;
  tree child_fn, t, c, src, dst, f, sf, arg, sarg, decl;
  tree record_type, srecord_type, bind, list;
  bool record_needs_remap = false, srecord_needs_remap = false;
  splay_tree_node n;
  struct omp_taskcopy_context tcctx;
  location_t loc = gimple_location (task_stmt);

  child_fn = gimple_omp_task_copy_fn (task_stmt);
  child_cfun = DECL_STRUCT_FUNCTION (child_fn);
  gcc_assert (child_cfun->cfg == NULL);
  DECL_SAVED_TREE (child_fn) = alloc_stmt_list ();

  /* Reset DECL_CONTEXT on function arguments.  */
  for (t = DECL_ARGUMENTS (child_fn); t; t = DECL_CHAIN (t))
    DECL_CONTEXT (t) = child_fn;

  /* Populate the function.  */
  push_gimplify_context ();
  push_cfun (child_cfun);

  bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
  TREE_SIDE_EFFECTS (bind) = 1;
  list = NULL;
  DECL_SAVED_TREE (child_fn) = bind;
  DECL_SOURCE_LOCATION (child_fn) = gimple_location (task_stmt);

  /* Remap src and dst argument types if needed.  */
  record_type = ctx->record_type;
  srecord_type = ctx->srecord_type;
  for (f = TYPE_FIELDS (record_type); f ; f = DECL_CHAIN (f))
    if (variably_modified_type_p (TREE_TYPE (f), ctx->cb.src_fn))
      {
        record_needs_remap = true;
        break;
      }
  for (f = TYPE_FIELDS (srecord_type); f ; f = DECL_CHAIN (f))
    if (variably_modified_type_p (TREE_TYPE (f), ctx->cb.src_fn))
      {
        srecord_needs_remap = true;
        break;
      }

  if (record_needs_remap || srecord_needs_remap)
    {
      memset (&tcctx, '\0', sizeof (tcctx));
      tcctx.cb.src_fn = ctx->cb.src_fn;
      tcctx.cb.dst_fn = child_fn;
      tcctx.cb.src_node = cgraph_node::get (tcctx.cb.src_fn);
      gcc_checking_assert (tcctx.cb.src_node);
      tcctx.cb.dst_node = tcctx.cb.src_node;
      tcctx.cb.src_cfun = ctx->cb.src_cfun;
      tcctx.cb.copy_decl = task_copyfn_copy_decl;
      tcctx.cb.eh_lp_nr = 0;
      tcctx.cb.transform_call_graph_edges = CB_CGE_MOVE;
      tcctx.cb.decl_map = new hash_map<tree, tree>;
      tcctx.ctx = ctx;

      if (record_needs_remap)
        record_type = task_copyfn_remap_type (&tcctx, record_type);
      if (srecord_needs_remap)
        srecord_type = task_copyfn_remap_type (&tcctx, srecord_type);
    }
  else
    tcctx.cb.decl_map = NULL;

  arg = DECL_ARGUMENTS (child_fn);
  TREE_TYPE (arg) = build_pointer_type (record_type);
  sarg = DECL_CHAIN (arg);
  TREE_TYPE (sarg) = build_pointer_type (srecord_type);

  /* First pass: initialize temporaries used in record_type and srecord_type
     sizes and field offsets.  */
  if (tcctx.cb.decl_map)
    for (c = gimple_omp_task_clauses (task_stmt); c; c = OMP_CLAUSE_CHAIN (c))
      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE)
        {
          tree *p;

          decl = OMP_CLAUSE_DECL (c);
          p = tcctx.cb.decl_map->get (decl);
          if (p == NULL)
            continue;
          n = splay_tree_lookup (ctx->sfield_map, (splay_tree_key) decl);
          sf = (tree) n->value;
          sf = *tcctx.cb.decl_map->get (sf);
          src = build_simple_mem_ref_loc (loc, sarg);
          src = omp_build_component_ref (src, sf);
          t = build2 (MODIFY_EXPR, TREE_TYPE (*p), *p, src);
          append_to_statement_list (t, &list);
        }

  /* Second pass: copy shared var pointers and copy construct non-VLA
     firstprivate vars.  */
  for (c = gimple_omp_task_clauses (task_stmt); c; c = OMP_CLAUSE_CHAIN (c))
    switch (OMP_CLAUSE_CODE (c))
      {
      case OMP_CLAUSE_SHARED:
        decl = OMP_CLAUSE_DECL (c);
        n = splay_tree_lookup (ctx->field_map, (splay_tree_key) decl);
        if (n == NULL)
          break;
        f = (tree) n->value;
        if (tcctx.cb.decl_map)
          f = *tcctx.cb.decl_map->get (f);
        n = splay_tree_lookup (ctx->sfield_map, (splay_tree_key) decl);
        sf = (tree) n->value;
        if (tcctx.cb.decl_map)
          sf = *tcctx.cb.decl_map->get (sf);
        src = build_simple_mem_ref_loc (loc, sarg);
        src = omp_build_component_ref (src, sf);
        dst = build_simple_mem_ref_loc (loc, arg);
        dst = omp_build_component_ref (dst, f);
        t = build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
        append_to_statement_list (t, &list);
        break;
      case OMP_CLAUSE_FIRSTPRIVATE:
        decl = OMP_CLAUSE_DECL (c);
        if (is_variable_sized (decl))
          break;
        n = splay_tree_lookup (ctx->field_map, (splay_tree_key) decl);
        if (n == NULL)
          break;
        f = (tree) n->value;
        if (tcctx.cb.decl_map)
          f = *tcctx.cb.decl_map->get (f);
        n = splay_tree_lookup (ctx->sfield_map, (splay_tree_key) decl);
        if (n != NULL)
          {
            sf = (tree) n->value;
            if (tcctx.cb.decl_map)
              sf = *tcctx.cb.decl_map->get (sf);
            src = build_simple_mem_ref_loc (loc, sarg);
            src = omp_build_component_ref (src, sf);
            if (use_pointer_for_field (decl, NULL) || is_reference (decl))
              src = build_simple_mem_ref_loc (loc, src);
          }
        else
          src = decl;
        dst = build_simple_mem_ref_loc (loc, arg);
        dst = omp_build_component_ref (dst, f);
        t = lang_hooks.decls.omp_clause_copy_ctor (c, dst, src);
        append_to_statement_list (t, &list);
        break;
      case OMP_CLAUSE_PRIVATE:
        if (! OMP_CLAUSE_PRIVATE_OUTER_REF (c))
          break;
        decl = OMP_CLAUSE_DECL (c);
        n = splay_tree_lookup (ctx->field_map, (splay_tree_key) decl);
        f = (tree) n->value;
        if (tcctx.cb.decl_map)
          f = *tcctx.cb.decl_map->get (f);
        n = splay_tree_lookup (ctx->sfield_map, (splay_tree_key) decl);
        if (n != NULL)
          {
            sf = (tree) n->value;
            if (tcctx.cb.decl_map)
              sf = *tcctx.cb.decl_map->get (sf);
            src = build_simple_mem_ref_loc (loc, sarg);
            src = omp_build_component_ref (src, sf);
            if (use_pointer_for_field (decl, NULL))
              src = build_simple_mem_ref_loc (loc, src);
          }
        else
          src = decl;
        dst = build_simple_mem_ref_loc (loc, arg);
        dst = omp_build_component_ref (dst, f);
        t = build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
        append_to_statement_list (t, &list);
        break;
      default:
        break;
      }

  /* Last pass: handle VLA firstprivates.  */
  if (tcctx.cb.decl_map)
    for (c = gimple_omp_task_clauses (task_stmt); c; c = OMP_CLAUSE_CHAIN (c))
      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE)
        {
          tree ind, ptr, df;

          decl = OMP_CLAUSE_DECL (c);
          if (!is_variable_sized (decl))
            continue;
          n = splay_tree_lookup (ctx->field_map, (splay_tree_key) decl);
          if (n == NULL)
            continue;
          f = (tree) n->value;
          f = *tcctx.cb.decl_map->get (f);
          gcc_assert (DECL_HAS_VALUE_EXPR_P (decl));
          ind = DECL_VALUE_EXPR (decl);
          gcc_assert (TREE_CODE (ind) == INDIRECT_REF);
          gcc_assert (DECL_P (TREE_OPERAND (ind, 0)));
          n = splay_tree_lookup (ctx->sfield_map,
                                 (splay_tree_key) TREE_OPERAND (ind, 0));
          sf = (tree) n->value;
          sf = *tcctx.cb.decl_map->get (sf);
          src = build_simple_mem_ref_loc (loc, sarg);
          src = omp_build_component_ref (src, sf);
          src = build_simple_mem_ref_loc (loc, src);
          dst = build_simple_mem_ref_loc (loc, arg);
          dst = omp_build_component_ref (dst, f);
          t = lang_hooks.decls.omp_clause_copy_ctor (c, dst, src);
          append_to_statement_list (t, &list);
          n = splay_tree_lookup (ctx->field_map,
                                 (splay_tree_key) TREE_OPERAND (ind, 0));
          df = (tree) n->value;
          df = *tcctx.cb.decl_map->get (df);
          ptr = build_simple_mem_ref_loc (loc, arg);
          ptr = omp_build_component_ref (ptr, df);
          t = build2 (MODIFY_EXPR, TREE_TYPE (ptr), ptr,
                      build_fold_addr_expr_loc (loc, dst));
          append_to_statement_list (t, &list);
        }

  t = build1 (RETURN_EXPR, void_type_node, NULL);
  append_to_statement_list (t, &list);

  if (tcctx.cb.decl_map)
    delete tcctx.cb.decl_map;
  pop_gimplify_context (NULL);
  BIND_EXPR_BODY (bind) = list;
  pop_cfun ();
}

static void
lower_depend_clauses (gimple stmt, gimple_seq *iseq, gimple_seq *oseq)
{
  tree c, clauses;
  gimple g;
  size_t n_in = 0, n_out = 0, idx = 2, i;

  clauses = find_omp_clause (gimple_omp_task_clauses (stmt),
                             OMP_CLAUSE_DEPEND);
  gcc_assert (clauses);
  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
    if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_DEPEND)
      switch (OMP_CLAUSE_DEPEND_KIND (c))
        {
        case OMP_CLAUSE_DEPEND_IN:
          n_in++;
          break;
        case OMP_CLAUSE_DEPEND_OUT:
        case OMP_CLAUSE_DEPEND_INOUT:
          n_out++;
          break;
        default:
          gcc_unreachable ();
        }
  tree type = build_array_type_nelts (ptr_type_node, n_in + n_out + 2);
  tree array = create_tmp_var (type);
  tree r = build4 (ARRAY_REF, ptr_type_node, array, size_int (0), NULL_TREE,
                   NULL_TREE);
  g = gimple_build_assign (r, build_int_cst (ptr_type_node, n_in + n_out));
  gimple_seq_add_stmt (iseq, g);
  r = build4 (ARRAY_REF, ptr_type_node, array, size_int (1), NULL_TREE,
              NULL_TREE);
  g = gimple_build_assign (r, build_int_cst (ptr_type_node, n_out));
  gimple_seq_add_stmt (iseq, g);
  for (i = 0; i < 2; i++)
    {
      if ((i ? n_in : n_out) == 0)
        continue;
      for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
        if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_DEPEND
            && ((OMP_CLAUSE_DEPEND_KIND (c) != OMP_CLAUSE_DEPEND_IN) ^ i))
          {
            tree t = OMP_CLAUSE_DECL (c);
            t = fold_convert (ptr_type_node, t);
            gimplify_expr (&t, iseq, NULL, is_gimple_val, fb_rvalue);
            r = build4 (ARRAY_REF, ptr_type_node, array, size_int (idx++),
                        NULL_TREE, NULL_TREE);
            g = gimple_build_assign (r, t);
            gimple_seq_add_stmt (iseq, g);
          }
    }
  tree *p = gimple_omp_task_clauses_ptr (stmt);
  c = build_omp_clause (UNKNOWN_LOCATION, OMP_CLAUSE_DEPEND);
  OMP_CLAUSE_DECL (c) = build_fold_addr_expr (array);
  OMP_CLAUSE_CHAIN (c) = *p;
  *p = c;
  tree clobber = build_constructor (type, NULL);
  TREE_THIS_VOLATILE (clobber) = 1;
  g = gimple_build_assign (array, clobber);
  gimple_seq_add_stmt (oseq, g);
}

/* Lower the OpenMP parallel or task directive in the current statement
   in GSI_P.  CTX holds context information for the directive.  */

static void
lower_omp_taskreg (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree clauses;
  tree child_fn, t;
  gimple stmt = gsi_stmt (*gsi_p);
  gbind *par_bind, *bind, *dep_bind = NULL;
  gimple_seq par_body, olist, ilist, par_olist, par_rlist, par_ilist, new_body;
  location_t loc = gimple_location (stmt);

  clauses = gimple_omp_taskreg_clauses (stmt);
  par_bind
    = as_a <gbind *> (gimple_seq_first_stmt (gimple_omp_body (stmt)));
  par_body = gimple_bind_body (par_bind);
  child_fn = ctx->cb.dst_fn;
  if (gimple_code (stmt) == GIMPLE_OMP_PARALLEL
      && !gimple_omp_parallel_combined_p (stmt))
    {
      struct walk_stmt_info wi;
      int ws_num = 0;

      memset (&wi, 0, sizeof (wi));
      wi.info = &ws_num;
      wi.val_only = true;
      walk_gimple_seq (par_body, check_combined_parallel, NULL, &wi);
      if (ws_num == 1)
        gimple_omp_parallel_set_combined_p (stmt, true);
    }
  gimple_seq dep_ilist = NULL;
  gimple_seq dep_olist = NULL;
  if (gimple_code (stmt) == GIMPLE_OMP_TASK
      && find_omp_clause (clauses, OMP_CLAUSE_DEPEND))
    {
      push_gimplify_context ();
      dep_bind = gimple_build_bind (NULL, NULL, make_node (BLOCK));
      lower_depend_clauses (stmt, &dep_ilist, &dep_olist);
    }

  if (ctx->srecord_type)
    create_task_copyfn (as_a <gomp_task *> (stmt), ctx);

  push_gimplify_context ();

  par_olist = NULL;
  par_ilist = NULL;
  par_rlist = NULL;
  lower_rec_input_clauses (clauses, &par_ilist, &par_olist, ctx, NULL);
  lower_omp (&par_body, ctx);
  if (gimple_code (stmt) == GIMPLE_OMP_PARALLEL)
    lower_reduction_clauses (clauses, &par_rlist, ctx);

  /* Declare all the variables created by mapping and the variables
     declared in the scope of the parallel body.  */
  record_vars_into (ctx->block_vars, child_fn);
  record_vars_into (gimple_bind_vars (par_bind), child_fn);

  if (ctx->record_type)
    {
      ctx->sender_decl
        = create_tmp_var (ctx->srecord_type ? ctx->srecord_type
                          : ctx->record_type, ".omp_data_o");
      DECL_NAMELESS (ctx->sender_decl) = 1;
      TREE_ADDRESSABLE (ctx->sender_decl) = 1;
      gimple_omp_taskreg_set_data_arg (stmt, ctx->sender_decl);
    }

  olist = NULL;
  ilist = NULL;
  lower_send_clauses (clauses, &ilist, &olist, ctx);
  lower_send_shared_vars (&ilist, &olist, ctx);

  if (ctx->record_type)
    {
      tree clobber = build_constructor (TREE_TYPE (ctx->sender_decl), NULL);
      TREE_THIS_VOLATILE (clobber) = 1;
      gimple_seq_add_stmt (&olist, gimple_build_assign (ctx->sender_decl,
                                                        clobber));
    }

  /* Once all the expansions are done, sequence all the different
     fragments inside gimple_omp_body.  */

  new_body = NULL;

  if (ctx->record_type)
    {
      t = build_fold_addr_expr_loc (loc, ctx->sender_decl);
      /* fixup_child_record_type might have changed receiver_decl's type.  */
      t = fold_convert_loc (loc, TREE_TYPE (ctx->receiver_decl), t);
      gimple_seq_add_stmt (&new_body,
                           gimple_build_assign (ctx->receiver_decl, t));
    }

  gimple_seq_add_seq (&new_body, par_ilist);
  gimple_seq_add_seq (&new_body, par_body);
  gimple_seq_add_seq (&new_body, par_rlist);
  if (ctx->cancellable)
    gimple_seq_add_stmt (&new_body, gimple_build_label (ctx->cancel_label));
  gimple_seq_add_seq (&new_body, par_olist);
  new_body = maybe_catch_exception (new_body);
  if (gimple_code (stmt) == GIMPLE_OMP_TASK)
    gimple_seq_add_stmt (&new_body,
                         gimple_build_omp_continue (integer_zero_node,
                                                    integer_zero_node));
  gimple_seq_add_stmt (&new_body, gimple_build_omp_return (false));
  gimple_omp_set_body (stmt, new_body);

  bind = gimple_build_bind (NULL, NULL, gimple_bind_block (par_bind));
  gsi_replace (gsi_p, dep_bind ? dep_bind : bind, true);
  gimple_bind_add_seq (bind, ilist);
  gimple_bind_add_stmt (bind, stmt);
  gimple_bind_add_seq (bind, olist);

  pop_gimplify_context (NULL);

  if (dep_bind)
    {
      gimple_bind_add_seq (dep_bind, dep_ilist);
      gimple_bind_add_stmt (dep_bind, bind);
      gimple_bind_add_seq (dep_bind, dep_olist);
      pop_gimplify_context (dep_bind);
    }
}

/* Lower the GIMPLE_OMP_TARGET in the current statement
   in GSI_P.  CTX holds context information for the directive.  */

static void
lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  tree clauses;
  tree child_fn, t, c;
  gomp_target *stmt = as_a <gomp_target *> (gsi_stmt (*gsi_p));
  gbind *tgt_bind, *bind;
  gimple_seq tgt_body, olist, ilist, orlist, irlist, new_body;
  location_t loc = gimple_location (stmt);
  bool offloaded, data_region;
  unsigned int map_cnt = 0;

  offloaded = is_gimple_omp_offloaded (stmt);
  switch (gimple_omp_target_kind (stmt))
    {
    case GF_OMP_TARGET_KIND_REGION:
    case GF_OMP_TARGET_KIND_UPDATE:
    case GF_OMP_TARGET_KIND_OACC_PARALLEL:
    case GF_OMP_TARGET_KIND_OACC_KERNELS:
    case GF_OMP_TARGET_KIND_OACC_UPDATE:
    case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA:
      data_region = false;
      break;
    case GF_OMP_TARGET_KIND_DATA:
    case GF_OMP_TARGET_KIND_OACC_DATA:
      data_region = true;
      break;
    default:
      gcc_unreachable ();
    }

  clauses = gimple_omp_target_clauses (stmt);

  tgt_bind = NULL;
  tgt_body = NULL;
  if (offloaded)
    {
      tgt_bind = gimple_seq_first_stmt_as_a_bind (gimple_omp_body (stmt));
      tgt_body = gimple_bind_body (tgt_bind);
    }
  else if (data_region)
    tgt_body = gimple_omp_body (stmt);
  child_fn = ctx->cb.dst_fn;

  push_gimplify_context ();

  irlist = NULL;
  orlist = NULL;
  if (offloaded
      && is_gimple_omp_oacc (stmt))
    oacc_process_reduction_data (&tgt_body, &irlist, &orlist, ctx);

  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
    switch (OMP_CLAUSE_CODE (c))
      {
        tree var, x;

      default:
        break;
      case OMP_CLAUSE_MAP:
#ifdef ENABLE_CHECKING
        /* First check what we're prepared to handle in the following.  */
        switch (OMP_CLAUSE_MAP_KIND (c))
          {
          case GOMP_MAP_ALLOC:
          case GOMP_MAP_TO:
          case GOMP_MAP_FROM:
          case GOMP_MAP_TOFROM:
          case GOMP_MAP_POINTER:
          case GOMP_MAP_TO_PSET:
            break;
          case GOMP_MAP_FORCE_ALLOC:
          case GOMP_MAP_FORCE_TO:
          case GOMP_MAP_FORCE_FROM:
          case GOMP_MAP_FORCE_TOFROM:
          case GOMP_MAP_FORCE_PRESENT:
          case GOMP_MAP_FORCE_DEALLOC:
          case GOMP_MAP_FORCE_DEVICEPTR:
            gcc_assert (is_gimple_omp_oacc (stmt));
            break;
          default:
            gcc_unreachable ();
          }
#endif
          /* FALLTHRU */
      case OMP_CLAUSE_TO:
      case OMP_CLAUSE_FROM:
        var = OMP_CLAUSE_DECL (c);
        if (!DECL_P (var))
          {
            if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_MAP
                || !OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c))
              map_cnt++;
            continue;
          }

        if (DECL_SIZE (var)
            && TREE_CODE (DECL_SIZE (var)) != INTEGER_CST)
          {
            tree var2 = DECL_VALUE_EXPR (var);
            gcc_assert (TREE_CODE (var2) == INDIRECT_REF);
            var2 = TREE_OPERAND (var2, 0);
            gcc_assert (DECL_P (var2));
            var = var2;
          }

        if (!maybe_lookup_field (var, ctx))
          continue;

        if (offloaded)
          {
            x = build_receiver_ref (var, true, ctx);
            tree new_var = lookup_decl (var, ctx);
            if (OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
                && !OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c)
                && TREE_CODE (TREE_TYPE (var)) == ARRAY_TYPE)
              x = build_simple_mem_ref (x);
            SET_DECL_VALUE_EXPR (new_var, x);
            DECL_HAS_VALUE_EXPR_P (new_var) = 1;
          }
        map_cnt++;
      }

  if (offloaded)
    {
      target_nesting_level++;
      lower_omp (&tgt_body, ctx);
      target_nesting_level--;
    }
  else if (data_region)
    lower_omp (&tgt_body, ctx);

  if (offloaded)
    {
      /* Declare all the variables created by mapping and the variables
         declared in the scope of the target body.  */
      record_vars_into (ctx->block_vars, child_fn);
      record_vars_into (gimple_bind_vars (tgt_bind), child_fn);
    }

  olist = NULL;
  ilist = NULL;
  if (ctx->record_type)
    {
      ctx->sender_decl
        = create_tmp_var (ctx->record_type, ".omp_data_arr");
      DECL_NAMELESS (ctx->sender_decl) = 1;
      TREE_ADDRESSABLE (ctx->sender_decl) = 1;
      t = make_tree_vec (3);
      TREE_VEC_ELT (t, 0) = ctx->sender_decl;
      TREE_VEC_ELT (t, 1)
        = create_tmp_var (build_array_type_nelts (size_type_node, map_cnt),
                          ".omp_data_sizes");
      DECL_NAMELESS (TREE_VEC_ELT (t, 1)) = 1;
      TREE_ADDRESSABLE (TREE_VEC_ELT (t, 1)) = 1;
      TREE_STATIC (TREE_VEC_ELT (t, 1)) = 1;
      tree tkind_type;
      int talign_shift;
      if (is_gimple_omp_oacc (stmt))
        {
          tkind_type = short_unsigned_type_node;
          talign_shift = 8;
        }
      else
        {
          tkind_type = unsigned_char_type_node;
          talign_shift = 3;
        }
      TREE_VEC_ELT (t, 2)
        = create_tmp_var (build_array_type_nelts (tkind_type, map_cnt),
                          ".omp_data_kinds");
      DECL_NAMELESS (TREE_VEC_ELT (t, 2)) = 1;
      TREE_ADDRESSABLE (TREE_VEC_ELT (t, 2)) = 1;
      TREE_STATIC (TREE_VEC_ELT (t, 2)) = 1;
      gimple_omp_target_set_data_arg (stmt, t);

      vec<constructor_elt, va_gc> *vsize;
      vec<constructor_elt, va_gc> *vkind;
      vec_alloc (vsize, map_cnt);
      vec_alloc (vkind, map_cnt);
      unsigned int map_idx = 0;

      for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
        switch (OMP_CLAUSE_CODE (c))
          {
            tree ovar, nc;

          default:
            break;
          case OMP_CLAUSE_MAP:
          case OMP_CLAUSE_TO:
          case OMP_CLAUSE_FROM:
            nc = c;
            ovar = OMP_CLAUSE_DECL (c);
            if (!DECL_P (ovar))
              {
                if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
                    && OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c))
                  {
                    gcc_checking_assert (OMP_CLAUSE_DECL (OMP_CLAUSE_CHAIN (c))
                                         == get_base_address (ovar));
                    nc = OMP_CLAUSE_CHAIN (c);
                    ovar = OMP_CLAUSE_DECL (nc);
                  }
                else
                  {
                    tree x = build_sender_ref (ovar, ctx);
                    tree v
                      = build_fold_addr_expr_with_type (ovar, ptr_type_node);
                    gimplify_assign (x, v, &ilist);
                    nc = NULL_TREE;
                  }
              }
            else
              {
                if (DECL_SIZE (ovar)
                    && TREE_CODE (DECL_SIZE (ovar)) != INTEGER_CST)
                  {
                    tree ovar2 = DECL_VALUE_EXPR (ovar);
                    gcc_assert (TREE_CODE (ovar2) == INDIRECT_REF);
                    ovar2 = TREE_OPERAND (ovar2, 0);
                    gcc_assert (DECL_P (ovar2));
                    ovar = ovar2;
                  }
                if (!maybe_lookup_field (ovar, ctx))
                  continue;
              }

            unsigned int talign = TYPE_ALIGN_UNIT (TREE_TYPE (ovar));
            if (DECL_P (ovar) && DECL_ALIGN_UNIT (ovar) > talign)
              talign = DECL_ALIGN_UNIT (ovar);
            if (nc)
              {
                tree var = lookup_decl_in_outer_ctx (ovar, ctx);
                tree x = build_sender_ref (ovar, ctx);
                if (maybe_lookup_oacc_reduction (var, ctx))
                  {
                    gcc_checking_assert (offloaded
                                         && is_gimple_omp_oacc (stmt));
                    gimplify_assign (x, var, &ilist);
                  }
                else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
                         && OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
                         && !OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c)
                         && TREE_CODE (TREE_TYPE (ovar)) == ARRAY_TYPE)
                  {
                    gcc_assert (offloaded);
                    tree avar
                      = create_tmp_var (TREE_TYPE (TREE_TYPE (x)));
                    mark_addressable (avar);
                    gimplify_assign (avar, build_fold_addr_expr (var), &ilist);
                    talign = DECL_ALIGN_UNIT (avar);
                    avar = build_fold_addr_expr (avar);
                    gimplify_assign (x, avar, &ilist);
                  }
                else if (is_gimple_reg (var))
                  {
                    gcc_assert (offloaded);
                    tree avar = create_tmp_var (TREE_TYPE (var));
                    mark_addressable (avar);
                    enum gomp_map_kind map_kind = OMP_CLAUSE_MAP_KIND (c);
                    if (GOMP_MAP_COPY_TO_P (map_kind)
                        || map_kind == GOMP_MAP_POINTER
                        || map_kind == GOMP_MAP_TO_PSET
                        || map_kind == GOMP_MAP_FORCE_DEVICEPTR)
                      gimplify_assign (avar, var, &ilist);
                    avar = build_fold_addr_expr (avar);
                    gimplify_assign (x, avar, &ilist);
                    if ((GOMP_MAP_COPY_FROM_P (map_kind)
                         || map_kind == GOMP_MAP_FORCE_DEVICEPTR)
                        && !TYPE_READONLY (TREE_TYPE (var)))
                      {
                        x = build_sender_ref (ovar, ctx);
                        x = build_simple_mem_ref (x);
                        gimplify_assign (var, x, &olist);
                      }
                  }
                else
                  {
                    var = build_fold_addr_expr (var);
                    gimplify_assign (x, var, &ilist);
                  }
              }
            tree s = OMP_CLAUSE_SIZE (c);
            if (s == NULL_TREE)
              s = TYPE_SIZE_UNIT (TREE_TYPE (ovar));
            s = fold_convert (size_type_node, s);
            tree purpose = size_int (map_idx++);
            CONSTRUCTOR_APPEND_ELT (vsize, purpose, s);
            if (TREE_CODE (s) != INTEGER_CST)
              TREE_STATIC (TREE_VEC_ELT (t, 1)) = 0;

            unsigned HOST_WIDE_INT tkind;
            switch (OMP_CLAUSE_CODE (c))
              {
              case OMP_CLAUSE_MAP:
                tkind = OMP_CLAUSE_MAP_KIND (c);
                break;
              case OMP_CLAUSE_TO:
                tkind = GOMP_MAP_TO;
                break;
              case OMP_CLAUSE_FROM:
                tkind = GOMP_MAP_FROM;
                break;
              default:
                gcc_unreachable ();
              }
            gcc_checking_assert (tkind
                                 < (HOST_WIDE_INT_C (1U) << talign_shift));
            talign = ceil_log2 (talign);
            tkind |= talign << talign_shift;
            gcc_checking_assert (tkind
                                 <= tree_to_uhwi (TYPE_MAX_VALUE (tkind_type)));
            CONSTRUCTOR_APPEND_ELT (vkind, purpose,
                                    build_int_cstu (tkind_type, tkind));
            if (nc && nc != c)
              c = nc;
          }

      gcc_assert (map_idx == map_cnt);

      DECL_INITIAL (TREE_VEC_ELT (t, 1))
        = build_constructor (TREE_TYPE (TREE_VEC_ELT (t, 1)), vsize);
      DECL_INITIAL (TREE_VEC_ELT (t, 2))
        = build_constructor (TREE_TYPE (TREE_VEC_ELT (t, 2)), vkind);
      if (!TREE_STATIC (TREE_VEC_ELT (t, 1)))
        {
          gimple_seq initlist = NULL;
          force_gimple_operand (build1 (DECL_EXPR, void_type_node,
                                        TREE_VEC_ELT (t, 1)),
                                &initlist, true, NULL_TREE);
          gimple_seq_add_seq (&ilist, initlist);

          tree clobber = build_constructor (TREE_TYPE (TREE_VEC_ELT (t, 1)),
                                            NULL);
          TREE_THIS_VOLATILE (clobber) = 1;
          gimple_seq_add_stmt (&olist,
                               gimple_build_assign (TREE_VEC_ELT (t, 1),
                                                    clobber));
        }

      tree clobber = build_constructor (ctx->record_type, NULL);
      TREE_THIS_VOLATILE (clobber) = 1;
      gimple_seq_add_stmt (&olist, gimple_build_assign (ctx->sender_decl,
                                                        clobber));
    }

  /* Once all the expansions are done, sequence all the different
     fragments inside gimple_omp_body.  */

  new_body = NULL;

  if (offloaded
      && ctx->record_type)
    {
      t = build_fold_addr_expr_loc (loc, ctx->sender_decl);
      /* fixup_child_record_type might have changed receiver_decl's type.  */
      t = fold_convert_loc (loc, TREE_TYPE (ctx->receiver_decl), t);
      gimple_seq_add_stmt (&new_body,
                           gimple_build_assign (ctx->receiver_decl, t));
    }

  if (offloaded)
    {
      gimple_seq_add_seq (&new_body, tgt_body);
      new_body = maybe_catch_exception (new_body);
    }
  else if (data_region)
    new_body = tgt_body;
  if (offloaded || data_region)
    {
      gimple_seq_add_stmt (&new_body, gimple_build_omp_return (false));
      gimple_omp_set_body (stmt, new_body);
    }

  bind = gimple_build_bind (NULL, NULL,
                            tgt_bind ? gimple_bind_block (tgt_bind)
                                     : NULL_TREE);
  gsi_replace (gsi_p, bind, true);
  gimple_bind_add_seq (bind, irlist);
  gimple_bind_add_seq (bind, ilist);
  gimple_bind_add_stmt (bind, stmt);
  gimple_bind_add_seq (bind, olist);
  gimple_bind_add_seq (bind, orlist);

  pop_gimplify_context (NULL);
}

/* Expand code for an OpenMP teams directive.  */

static void
lower_omp_teams (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  gomp_teams *teams_stmt = as_a <gomp_teams *> (gsi_stmt (*gsi_p));
  push_gimplify_context ();

  tree block = make_node (BLOCK);
  gbind *bind = gimple_build_bind (NULL, NULL, block);
  gsi_replace (gsi_p, bind, true);
  gimple_seq bind_body = NULL;
  gimple_seq dlist = NULL;
  gimple_seq olist = NULL;

  tree num_teams = find_omp_clause (gimple_omp_teams_clauses (teams_stmt),
                                    OMP_CLAUSE_NUM_TEAMS);
  if (num_teams == NULL_TREE)
    num_teams = build_int_cst (unsigned_type_node, 0);
  else
    {
      num_teams = OMP_CLAUSE_NUM_TEAMS_EXPR (num_teams);
      num_teams = fold_convert (unsigned_type_node, num_teams);
      gimplify_expr (&num_teams, &bind_body, NULL, is_gimple_val, fb_rvalue);
    }
  tree thread_limit = find_omp_clause (gimple_omp_teams_clauses (teams_stmt),
                                       OMP_CLAUSE_THREAD_LIMIT);
  if (thread_limit == NULL_TREE)
    thread_limit = build_int_cst (unsigned_type_node, 0);
  else
    {
      thread_limit = OMP_CLAUSE_THREAD_LIMIT_EXPR (thread_limit);
      thread_limit = fold_convert (unsigned_type_node, thread_limit);
      gimplify_expr (&thread_limit, &bind_body, NULL, is_gimple_val,
                     fb_rvalue);
    }

  lower_rec_input_clauses (gimple_omp_teams_clauses (teams_stmt),
                           &bind_body, &dlist, ctx, NULL);
  lower_omp (gimple_omp_body_ptr (teams_stmt), ctx);
  lower_reduction_clauses (gimple_omp_teams_clauses (teams_stmt), &olist, ctx);
  gimple_seq_add_stmt (&bind_body, teams_stmt);

  location_t loc = gimple_location (teams_stmt);
  tree decl = builtin_decl_explicit (BUILT_IN_GOMP_TEAMS);
  gimple call = gimple_build_call (decl, 2, num_teams, thread_limit);
  gimple_set_location (call, loc);
  gimple_seq_add_stmt (&bind_body, call);

  gimple_seq_add_seq (&bind_body, gimple_omp_body (teams_stmt));
  gimple_omp_set_body (teams_stmt, NULL);
  gimple_seq_add_seq (&bind_body, olist);
  gimple_seq_add_seq (&bind_body, dlist);
  gimple_seq_add_stmt (&bind_body, gimple_build_omp_return (true));
  gimple_bind_set_body (bind, bind_body);

  pop_gimplify_context (bind);

  gimple_bind_append_vars (bind, ctx->block_vars);
  BLOCK_VARS (block) = ctx->block_vars;
  if (BLOCK_VARS (block))
    TREE_USED (block) = 1;
}


/* Callback for lower_omp_1.  Return non-NULL if *tp needs to be
   regimplified.  If DATA is non-NULL, lower_omp_1 is outside
   of OMP context, but with task_shared_vars set.  */

static tree
lower_omp_regimplify_p (tree *tp, int *walk_subtrees,
                        void *data)
{
  tree t = *tp;

  /* Any variable with DECL_VALUE_EXPR needs to be regimplified.  */
  if (TREE_CODE (t) == VAR_DECL && data == NULL && DECL_HAS_VALUE_EXPR_P (t))
    return t;

  if (task_shared_vars
      && DECL_P (t)
      && bitmap_bit_p (task_shared_vars, DECL_UID (t)))
    return t;

  /* If a global variable has been privatized, TREE_CONSTANT on
     ADDR_EXPR might be wrong.  */
  if (data == NULL && TREE_CODE (t) == ADDR_EXPR)
    recompute_tree_invariant_for_addr_expr (t);

  *walk_subtrees = !TYPE_P (t) && !DECL_P (t);
  return NULL_TREE;
}

static void
lower_omp_1 (gimple_stmt_iterator *gsi_p, omp_context *ctx)
{
  gimple stmt = gsi_stmt (*gsi_p);
  struct walk_stmt_info wi;
  gcall *call_stmt;

  if (gimple_has_location (stmt))
    input_location = gimple_location (stmt);

  if (task_shared_vars)
    memset (&wi, '\0', sizeof (wi));

  /* If we have issued syntax errors, avoid doing any heavy lifting.
     Just replace the OMP directives with a NOP to avoid
     confusing RTL expansion.  */
  if (seen_error () && is_gimple_omp (stmt))
    {
      gsi_replace (gsi_p, gimple_build_nop (), true);
      return;
    }

  switch (gimple_code (stmt))
    {
    case GIMPLE_COND:
      {
        gcond *cond_stmt = as_a <gcond *> (stmt);
        if ((ctx || task_shared_vars)
            && (walk_tree (gimple_cond_lhs_ptr (cond_stmt),
                           lower_omp_regimplify_p,
                           ctx ? NULL : &wi, NULL)
                || walk_tree (gimple_cond_rhs_ptr (cond_stmt),
                              lower_omp_regimplify_p,
                              ctx ? NULL : &wi, NULL)))
          gimple_regimplify_operands (cond_stmt, gsi_p);
      }
      break;
    case GIMPLE_CATCH:
      lower_omp (gimple_catch_handler_ptr (as_a <gcatch *> (stmt)), ctx);
      break;
    case GIMPLE_EH_FILTER:
      lower_omp (gimple_eh_filter_failure_ptr (stmt), ctx);
      break;
    case GIMPLE_TRY:
      lower_omp (gimple_try_eval_ptr (stmt), ctx);
      lower_omp (gimple_try_cleanup_ptr (stmt), ctx);
      break;
    case GIMPLE_TRANSACTION:
      lower_omp (gimple_transaction_body_ptr (
                   as_a <gtransaction *> (stmt)),
                 ctx);
      break;
    case GIMPLE_BIND:
      lower_omp (gimple_bind_body_ptr (as_a <gbind *> (stmt)), ctx);
      break;
    case GIMPLE_OMP_PARALLEL:
    case GIMPLE_OMP_TASK:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      if (ctx->cancellable)
        ctx->cancel_label = create_artificial_label (UNKNOWN_LOCATION);
      lower_omp_taskreg (gsi_p, ctx);
      break;
    case GIMPLE_OMP_FOR:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      if (ctx->cancellable)
        ctx->cancel_label = create_artificial_label (UNKNOWN_LOCATION);
      lower_omp_for (gsi_p, ctx);
      break;
    case GIMPLE_OMP_SECTIONS:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      if (ctx->cancellable)
        ctx->cancel_label = create_artificial_label (UNKNOWN_LOCATION);
      lower_omp_sections (gsi_p, ctx);
      break;
    case GIMPLE_OMP_SINGLE:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_single (gsi_p, ctx);
      break;
    case GIMPLE_OMP_MASTER:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_master (gsi_p, ctx);
      break;
    case GIMPLE_OMP_TASKGROUP:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_taskgroup (gsi_p, ctx);
      break;
    case GIMPLE_OMP_ORDERED:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_ordered (gsi_p, ctx);
      break;
    case GIMPLE_OMP_CRITICAL:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_critical (gsi_p, ctx);
      break;
    case GIMPLE_OMP_ATOMIC_LOAD:
      if ((ctx || task_shared_vars)
          && walk_tree (gimple_omp_atomic_load_rhs_ptr (
                          as_a <gomp_atomic_load *> (stmt)),
                        lower_omp_regimplify_p, ctx ? NULL : &wi, NULL))
        gimple_regimplify_operands (stmt, gsi_p);
      break;
    case GIMPLE_OMP_TARGET:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_target (gsi_p, ctx);
      break;
    case GIMPLE_OMP_TEAMS:
      ctx = maybe_lookup_ctx (stmt);
      gcc_assert (ctx);
      lower_omp_teams (gsi_p, ctx);
      break;
    case GIMPLE_CALL:
      tree fndecl;
      call_stmt = as_a <gcall *> (stmt);
      fndecl = gimple_call_fndecl (call_stmt);
      if (fndecl
          && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
        switch (DECL_FUNCTION_CODE (fndecl))
          {
          case BUILT_IN_GOMP_BARRIER:
            if (ctx == NULL)
              break;
            /* FALLTHRU */
          case BUILT_IN_GOMP_CANCEL:
          case BUILT_IN_GOMP_CANCELLATION_POINT:
            omp_context *cctx;
            cctx = ctx;
            if (gimple_code (cctx->stmt) == GIMPLE_OMP_SECTION)
              cctx = cctx->outer;
            gcc_assert (gimple_call_lhs (call_stmt) == NULL_TREE);
            if (!cctx->cancellable)
              {
                if (DECL_FUNCTION_CODE (fndecl)
                    == BUILT_IN_GOMP_CANCELLATION_POINT)
                  {
                    stmt = gimple_build_nop ();
                    gsi_replace (gsi_p, stmt, false);
                  }
                break;
              }
            if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_GOMP_BARRIER)
              {
                fndecl = builtin_decl_explicit (BUILT_IN_GOMP_BARRIER_CANCEL);
                gimple_call_set_fndecl (call_stmt, fndecl);
                gimple_call_set_fntype (call_stmt, TREE_TYPE (fndecl));
              }
            tree lhs;
            lhs = create_tmp_var (TREE_TYPE (TREE_TYPE (fndecl)));
            gimple_call_set_lhs (call_stmt, lhs);
            tree fallthru_label;
            fallthru_label = create_artificial_label (UNKNOWN_LOCATION);
            gimple g;
            g = gimple_build_label (fallthru_label);
            gsi_insert_after (gsi_p, g, GSI_SAME_STMT);
            g = gimple_build_cond (NE_EXPR, lhs,
                                   fold_convert (TREE_TYPE (lhs),
                                                 boolean_false_node),
                                   cctx->cancel_label, fallthru_label);
            gsi_insert_after (gsi_p, g, GSI_SAME_STMT);
            break;
          default:
            break;
          }
      /* FALLTHRU */
    default:
      if ((ctx || task_shared_vars)
          && walk_gimple_op (stmt, lower_omp_regimplify_p,
                             ctx ? NULL : &wi))
        {
          /* Just remove clobbers, this should happen only if we have
             "privatized" local addressable variables in SIMD regions,
             the clobber isn't needed in that case and gimplifying address
             of the ARRAY_REF into a pointer and creating MEM_REF based
             clobber would create worse code than we get with the clobber
             dropped.  */
          if (gimple_clobber_p (stmt))
            {
              gsi_replace (gsi_p, gimple_build_nop (), true);
              break;
            }
          gimple_regimplify_operands (stmt, gsi_p);
        }
      break;
    }
}

static void
lower_omp (gimple_seq *body, omp_context *ctx)
{
  location_t saved_location = input_location;
  gimple_stmt_iterator gsi;
  for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
    lower_omp_1 (&gsi, ctx);
  /* During gimplification, we haven't folded statments inside offloading
     or taskreg regions (gimplify.c:maybe_fold_stmt); do that now.  */
  if (target_nesting_level || taskreg_nesting_level)
    for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
      fold_stmt (&gsi);
  input_location = saved_location;
}
\f
/* Main entry point.  */

static unsigned int
execute_lower_omp (void)
{
  gimple_seq body;
  int i;
  omp_context *ctx;

  /* This pass always runs, to provide PROP_gimple_lomp.
     But often, there is nothing to do.  */
  if (flag_cilkplus == 0 && flag_openacc == 0 && flag_openmp == 0
      && flag_openmp_simd == 0)
    return 0;

  all_contexts = splay_tree_new (splay_tree_compare_pointers, 0,
                                 delete_omp_context);

  body = gimple_body (current_function_decl);
  scan_omp (&body, NULL);
  gcc_assert (taskreg_nesting_level == 0);
  FOR_EACH_VEC_ELT (taskreg_contexts, i, ctx)
    finish_taskreg_scan (ctx);
  taskreg_contexts.release ();

  if (all_contexts->root)
    {
      if (task_shared_vars)
        push_gimplify_context ();
      lower_omp (&body, NULL);
      if (task_shared_vars)
        pop_gimplify_context (NULL);
    }

  if (all_contexts)
    {
      splay_tree_delete (all_contexts);
      all_contexts = NULL;
    }
  BITMAP_FREE (task_shared_vars);
  return 0;
}

namespace {

const pass_data pass_data_lower_omp =
{
  GIMPLE_PASS, /* type */
  "omplower", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  PROP_gimple_any, /* properties_required */
  PROP_gimple_lomp, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_lower_omp : public gimple_opt_pass
{
public:
  pass_lower_omp (gcc::context *ctxt)
    : gimple_opt_pass (pass_data_lower_omp, ctxt)
  {}

  /* opt_pass methods: */
  virtual unsigned int execute (function *) { return execute_lower_omp (); }

}; // class pass_lower_omp

} // anon namespace

gimple_opt_pass *
make_pass_lower_omp (gcc::context *ctxt)
{
  return new pass_lower_omp (ctxt);
}
\f
/* The following is a utility to diagnose structured block violations.
   It is not part of the "omplower" pass, as that's invoked too late.  It
   should be invoked by the respective front ends after gimplification.  */

static splay_tree all_labels;

/* Check for mismatched contexts and generate an error if needed.  Return
   true if an error is detected.  */

static bool
diagnose_sb_0 (gimple_stmt_iterator *gsi_p,
               gimple branch_ctx, gimple label_ctx)
{
  gcc_checking_assert (!branch_ctx || is_gimple_omp (branch_ctx));
  gcc_checking_assert (!label_ctx || is_gimple_omp (label_ctx));

  if (label_ctx == branch_ctx)
    return false;

  const char* kind = NULL;

  if (flag_cilkplus)
    {
      if ((branch_ctx
           && gimple_code (branch_ctx) == GIMPLE_OMP_FOR
           && gimple_omp_for_kind (branch_ctx) == GF_OMP_FOR_KIND_CILKSIMD)
          || (label_ctx
              && gimple_code (label_ctx) == GIMPLE_OMP_FOR
              && gimple_omp_for_kind (label_ctx) == GF_OMP_FOR_KIND_CILKSIMD))
        kind = "Cilk Plus";
    }
  if (flag_openacc)
    {
      if ((branch_ctx && is_gimple_omp_oacc (branch_ctx))
          || (label_ctx && is_gimple_omp_oacc (label_ctx)))
        {
          gcc_checking_assert (kind == NULL);
          kind = "OpenACC";
        }
    }
  if (kind == NULL)
    {
      gcc_checking_assert (flag_openmp);
      kind = "OpenMP";
    }

  /*
     Previously we kept track of the label's entire context in diagnose_sb_[12]
     so we could traverse it and issue a correct "exit" or "enter" error
     message upon a structured block violation.

     We built the context by building a list with tree_cons'ing, but there is
     no easy counterpart in gimple tuples.  It seems like far too much work
     for issuing exit/enter error messages.  If someone really misses the
     distinct error message... patches welcome.
   */

#if 0
  /* Try to avoid confusing the user by producing and error message
     with correct "exit" or "enter" verbiage.  We prefer "exit"
     unless we can show that LABEL_CTX is nested within BRANCH_CTX.  */
  if (branch_ctx == NULL)
    exit_p = false;
  else
    {
      while (label_ctx)
        {
          if (TREE_VALUE (label_ctx) == branch_ctx)
            {
              exit_p = false;
              break;
            }
          label_ctx = TREE_CHAIN (label_ctx);
        }
    }

  if (exit_p)
    error ("invalid exit from %s structured block", kind);
  else
    error ("invalid entry to %s structured block", kind);
#endif

  /* If it's obvious we have an invalid entry, be specific about the error.  */
  if (branch_ctx == NULL)
    error ("invalid entry to %s structured block", kind);
  else
    {
      /* Otherwise, be vague and lazy, but efficient.  */
      error ("invalid branch to/from %s structured block", kind);
    }

  gsi_replace (gsi_p, gimple_build_nop (), false);
  return true;
}

/* Pass 1: Create a minimal tree of structured blocks, and record
   where each label is found.  */

static tree
diagnose_sb_1 (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
               struct walk_stmt_info *wi)
{
  gimple context = (gimple) wi->info;
  gimple inner_context;
  gimple stmt = gsi_stmt (*gsi_p);

  *handled_ops_p = true;

  switch (gimple_code (stmt))
    {
    WALK_SUBSTMTS;

    case GIMPLE_OMP_PARALLEL:
    case GIMPLE_OMP_TASK:
    case GIMPLE_OMP_SECTIONS:
    case GIMPLE_OMP_SINGLE:
    case GIMPLE_OMP_SECTION:
    case GIMPLE_OMP_MASTER:
    case GIMPLE_OMP_ORDERED:
    case GIMPLE_OMP_CRITICAL:
    case GIMPLE_OMP_TARGET:
    case GIMPLE_OMP_TEAMS:
    case GIMPLE_OMP_TASKGROUP:
      /* The minimal context here is just the current OMP construct.  */
      inner_context = stmt;
      wi->info = inner_context;
      walk_gimple_seq (gimple_omp_body (stmt), diagnose_sb_1, NULL, wi);
      wi->info = context;
      break;

    case GIMPLE_OMP_FOR:
      inner_context = stmt;
      wi->info = inner_context;
      /* gimple_omp_for_{index,initial,final} are all DECLs; no need to
         walk them.  */
      walk_gimple_seq (gimple_omp_for_pre_body (stmt),
                       diagnose_sb_1, NULL, wi);
      walk_gimple_seq (gimple_omp_body (stmt), diagnose_sb_1, NULL, wi);
      wi->info = context;
      break;

    case GIMPLE_LABEL:
      splay_tree_insert (all_labels,
                         (splay_tree_key) gimple_label_label (
                                            as_a <glabel *> (stmt)),
                         (splay_tree_value) context);
      break;

    default:
      break;
    }

  return NULL_TREE;
}

/* Pass 2: Check each branch and see if its context differs from that of
   the destination label's context.  */

static tree
diagnose_sb_2 (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
               struct walk_stmt_info *wi)
{
  gimple context = (gimple) wi->info;
  splay_tree_node n;
  gimple stmt = gsi_stmt (*gsi_p);

  *handled_ops_p = true;

  switch (gimple_code (stmt))
    {
    WALK_SUBSTMTS;

    case GIMPLE_OMP_PARALLEL:
    case GIMPLE_OMP_TASK:
    case GIMPLE_OMP_SECTIONS:
    case GIMPLE_OMP_SINGLE:
    case GIMPLE_OMP_SECTION:
    case GIMPLE_OMP_MASTER:
    case GIMPLE_OMP_ORDERED:
    case GIMPLE_OMP_CRITICAL:
    case GIMPLE_OMP_TARGET:
    case GIMPLE_OMP_TEAMS:
    case GIMPLE_OMP_TASKGROUP:
      wi->info = stmt;
      walk_gimple_seq_mod (gimple_omp_body_ptr (stmt), diagnose_sb_2, NULL, wi);
      wi->info = context;
      break;

    case GIMPLE_OMP_FOR:
      wi->info = stmt;
      /* gimple_omp_for_{index,initial,final} are all DECLs; no need to
         walk them.  */
      walk_gimple_seq_mod (gimple_omp_for_pre_body_ptr (stmt),
                           diagnose_sb_2, NULL, wi);
      walk_gimple_seq_mod (gimple_omp_body_ptr (stmt), diagnose_sb_2, NULL, wi);
      wi->info = context;
      break;

    case GIMPLE_COND:
        {
          gcond *cond_stmt = as_a <gcond *> (stmt);
          tree lab = gimple_cond_true_label (cond_stmt);
          if (lab)
            {
              n = splay_tree_lookup (all_labels,
                                     (splay_tree_key) lab);
              diagnose_sb_0 (gsi_p, context,
                             n ? (gimple) n->value : NULL);
            }
          lab = gimple_cond_false_label (cond_stmt);
          if (lab)
            {
              n = splay_tree_lookup (all_labels,
                                     (splay_tree_key) lab);
              diagnose_sb_0 (gsi_p, context,
                             n ? (gimple) n->value : NULL);
            }
        }
      break;

    case GIMPLE_GOTO:
      {
        tree lab = gimple_goto_dest (stmt);
        if (TREE_CODE (lab) != LABEL_DECL)
          break;

        n = splay_tree_lookup (all_labels, (splay_tree_key) lab);
        diagnose_sb_0 (gsi_p, context, n ? (gimple) n->value : NULL);
      }
      break;

    case GIMPLE_SWITCH:
      {
        gswitch *switch_stmt = as_a <gswitch *> (stmt);
        unsigned int i;
        for (i = 0; i < gimple_switch_num_labels (switch_stmt); ++i)
          {
            tree lab = CASE_LABEL (gimple_switch_label (switch_stmt, i));
            n = splay_tree_lookup (all_labels, (splay_tree_key) lab);
            if (n && diagnose_sb_0 (gsi_p, context, (gimple) n->value))
              break;
          }
      }
      break;

    case GIMPLE_RETURN:
      diagnose_sb_0 (gsi_p, context, NULL);
      break;

    default:
      break;
    }

  return NULL_TREE;
}

/* Called from tree-cfg.c::make_edges to create cfg edges for all relevant
   GIMPLE_* codes.  */
bool
make_gimple_omp_edges (basic_block bb, struct omp_region **region,
                       int *region_idx)
{
  gimple last = last_stmt (bb);
  enum gimple_code code = gimple_code (last);
  struct omp_region *cur_region = *region;
  bool fallthru = false;

  switch (code)
    {
    case GIMPLE_OMP_PARALLEL:
    case GIMPLE_OMP_TASK:
    case GIMPLE_OMP_FOR:
    case GIMPLE_OMP_SINGLE:
    case GIMPLE_OMP_TEAMS:
    case GIMPLE_OMP_MASTER:
    case GIMPLE_OMP_TASKGROUP:
    case GIMPLE_OMP_ORDERED:
    case GIMPLE_OMP_CRITICAL:
    case GIMPLE_OMP_SECTION:
      cur_region = new_omp_region (bb, code, cur_region);
      fallthru = true;
      break;

    case GIMPLE_OMP_TARGET:
      cur_region = new_omp_region (bb, code, cur_region);
      fallthru = true;
      switch (gimple_omp_target_kind (last))
        {
        case GF_OMP_TARGET_KIND_REGION:
        case GF_OMP_TARGET_KIND_DATA:
        case GF_OMP_TARGET_KIND_OACC_PARALLEL:
        case GF_OMP_TARGET_KIND_OACC_KERNELS:
        case GF_OMP_TARGET_KIND_OACC_DATA:
          break;
        case GF_OMP_TARGET_KIND_UPDATE:
        case GF_OMP_TARGET_KIND_OACC_UPDATE:
        case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA:
          cur_region = cur_region->outer;
          break;
        default:
          gcc_unreachable ();
        }
      break;

    case GIMPLE_OMP_SECTIONS:
      cur_region = new_omp_region (bb, code, cur_region);
      fallthru = true;
      break;

    case GIMPLE_OMP_SECTIONS_SWITCH:
      fallthru = false;
      break;

    case GIMPLE_OMP_ATOMIC_LOAD:
    case GIMPLE_OMP_ATOMIC_STORE:
       fallthru = true;
       break;

    case GIMPLE_OMP_RETURN:
      /* In the case of a GIMPLE_OMP_SECTION, the edge will go
         somewhere other than the next block.  This will be
         created later.  */
      cur_region->exit = bb;
      if (cur_region->type == GIMPLE_OMP_TASK)
        /* Add an edge corresponding to not scheduling the task
           immediately.  */
        make_edge (cur_region->entry, bb, EDGE_ABNORMAL);
      fallthru = cur_region->type != GIMPLE_OMP_SECTION;
      cur_region = cur_region->outer;
      break;

    case GIMPLE_OMP_CONTINUE:
      cur_region->cont = bb;
      switch (cur_region->type)
        {
        case GIMPLE_OMP_FOR:
          /* Mark all GIMPLE_OMP_FOR and GIMPLE_OMP_CONTINUE
             succs edges as abnormal to prevent splitting
             them.  */
          single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
          /* Make the loopback edge.  */
          make_edge (bb, single_succ (cur_region->entry),
                     EDGE_ABNORMAL);

          /* Create an edge from GIMPLE_OMP_FOR to exit, which
             corresponds to the case that the body of the loop
             is not executed at all.  */
          make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
          make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
          fallthru = false;
          break;

        case GIMPLE_OMP_SECTIONS:
          /* Wire up the edges into and out of the nested sections.  */
          {
            basic_block switch_bb = single_succ (cur_region->entry);

            struct omp_region *i;
            for (i = cur_region->inner; i ; i = i->next)
              {
                gcc_assert (i->type == GIMPLE_OMP_SECTION);
                make_edge (switch_bb, i->entry, 0);
                make_edge (i->exit, bb, EDGE_FALLTHRU);
              }

            /* Make the loopback edge to the block with
               GIMPLE_OMP_SECTIONS_SWITCH.  */
            make_edge (bb, switch_bb, 0);

            /* Make the edge from the switch to exit.  */
            make_edge (switch_bb, bb->next_bb, 0);
            fallthru = false;
          }
          break;

        case GIMPLE_OMP_TASK:
          fallthru = true;
          break;

        default:
          gcc_unreachable ();
        }
      break;

    default:
      gcc_unreachable ();
    }

  if (*region != cur_region)
    {
      *region = cur_region;
      if (cur_region)
        *region_idx = cur_region->entry->index;
      else
        *region_idx = 0;
    }

  return fallthru;
}

static unsigned int
diagnose_omp_structured_block_errors (void)
{
  struct walk_stmt_info wi;
  gimple_seq body = gimple_body (current_function_decl);

  all_labels = splay_tree_new (splay_tree_compare_pointers, 0, 0);

  memset (&wi, 0, sizeof (wi));
  walk_gimple_seq (body, diagnose_sb_1, NULL, &wi);

  memset (&wi, 0, sizeof (wi));
  wi.want_locations = true;
  walk_gimple_seq_mod (&body, diagnose_sb_2, NULL, &wi);

  gimple_set_body (current_function_decl, body);

  splay_tree_delete (all_labels);
  all_labels = NULL;

  return 0;
}

namespace {

const pass_data pass_data_diagnose_omp_blocks =
{
  GIMPLE_PASS, /* type */
  "*diagnose_omp_blocks", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  PROP_gimple_any, /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_diagnose_omp_blocks : public gimple_opt_pass
{
public:
  pass_diagnose_omp_blocks (gcc::context *ctxt)
    : gimple_opt_pass (pass_data_diagnose_omp_blocks, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *)
  {
    return flag_cilkplus || flag_openacc || flag_openmp;
  }
  virtual unsigned int execute (function *)
    {
      return diagnose_omp_structured_block_errors ();
    }

}; // class pass_diagnose_omp_blocks

} // anon namespace

gimple_opt_pass *
make_pass_diagnose_omp_blocks (gcc::context *ctxt)
{
  return new pass_diagnose_omp_blocks (ctxt);
}
\f
/* SIMD clone supporting code.  */

/* Allocate a fresh `simd_clone' and return it.  NARGS is the number
   of arguments to reserve space for.  */

static struct cgraph_simd_clone *
simd_clone_struct_alloc (int nargs)
{
  struct cgraph_simd_clone *clone_info;
  size_t len = (sizeof (struct cgraph_simd_clone)
                + nargs * sizeof (struct cgraph_simd_clone_arg));
  clone_info = (struct cgraph_simd_clone *)
               ggc_internal_cleared_alloc (len);
  return clone_info;
}

/* Make a copy of the `struct cgraph_simd_clone' in FROM to TO.  */

static inline void
simd_clone_struct_copy (struct cgraph_simd_clone *to,
                        struct cgraph_simd_clone *from)
{
  memcpy (to, from, (sizeof (struct cgraph_simd_clone)
                     + ((from->nargs - from->inbranch)
                        * sizeof (struct cgraph_simd_clone_arg))));
}

/* Return vector of parameter types of function FNDECL.  This uses
   TYPE_ARG_TYPES if available, otherwise falls back to types of
   DECL_ARGUMENTS types.  */

vec<tree>
simd_clone_vector_of_formal_parm_types (tree fndecl)
{
  if (TYPE_ARG_TYPES (TREE_TYPE (fndecl)))
    return ipa_get_vector_of_formal_parm_types (TREE_TYPE (fndecl));
  vec<tree> args = ipa_get_vector_of_formal_parms (fndecl);
  unsigned int i;
  tree arg;
  FOR_EACH_VEC_ELT (args, i, arg)
    args[i] = TREE_TYPE (args[i]);
  return args;
}

/* Given a simd function in NODE, extract the simd specific
   information from the OMP clauses passed in CLAUSES, and return
   the struct cgraph_simd_clone * if it should be cloned.  *INBRANCH_SPECIFIED
   is set to TRUE if the `inbranch' or `notinbranch' clause specified,
   otherwise set to FALSE.  */

static struct cgraph_simd_clone *
simd_clone_clauses_extract (struct cgraph_node *node, tree clauses,
                            bool *inbranch_specified)
{
  vec<tree> args = simd_clone_vector_of_formal_parm_types (node->decl);
  tree t;
  int n;
  *inbranch_specified = false;

  n = args.length ();
  if (n > 0 && args.last () == void_type_node)
    n--;

  /* To distinguish from an OpenMP simd clone, Cilk Plus functions to
     be cloned have a distinctive artificial label in addition to "omp
     declare simd".  */
  bool cilk_clone
    = (flag_cilkplus
       && lookup_attribute ("cilk simd function",
                            DECL_ATTRIBUTES (node->decl)));

  /* Allocate one more than needed just in case this is an in-branch
     clone which will require a mask argument.  */
  struct cgraph_simd_clone *clone_info = simd_clone_struct_alloc (n + 1);
  clone_info->nargs = n;
  clone_info->cilk_elemental = cilk_clone;

  if (!clauses)
    {
      args.release ();
      return clone_info;
    }
  clauses = TREE_VALUE (clauses);
  if (!clauses || TREE_CODE (clauses) != OMP_CLAUSE)
    return clone_info;

  for (t = clauses; t; t = OMP_CLAUSE_CHAIN (t))
    {
      switch (OMP_CLAUSE_CODE (t))
        {
        case OMP_CLAUSE_INBRANCH:
          clone_info->inbranch = 1;
          *inbranch_specified = true;
          break;
        case OMP_CLAUSE_NOTINBRANCH:
          clone_info->inbranch = 0;
          *inbranch_specified = true;
          break;
        case OMP_CLAUSE_SIMDLEN:
          clone_info->simdlen
            = TREE_INT_CST_LOW (OMP_CLAUSE_SIMDLEN_EXPR (t));
          break;
        case OMP_CLAUSE_LINEAR:
          {
            tree decl = OMP_CLAUSE_DECL (t);
            tree step = OMP_CLAUSE_LINEAR_STEP (t);
            int argno = TREE_INT_CST_LOW (decl);
            if (OMP_CLAUSE_LINEAR_VARIABLE_STRIDE (t))
              {
                clone_info->args[argno].arg_type
                  = SIMD_CLONE_ARG_TYPE_LINEAR_VARIABLE_STEP;
                clone_info->args[argno].linear_step = tree_to_shwi (step);
                gcc_assert (clone_info->args[argno].linear_step >= 0
                            && clone_info->args[argno].linear_step < n);
              }
            else
              {
                if (POINTER_TYPE_P (args[argno]))
                  step = fold_convert (ssizetype, step);
                if (!tree_fits_shwi_p (step))
                  {
                    warning_at (OMP_CLAUSE_LOCATION (t), 0,
                                "ignoring large linear step");
                    args.release ();
                    return NULL;
                  }
                else if (integer_zerop (step))
                  {
                    warning_at (OMP_CLAUSE_LOCATION (t), 0,
                                "ignoring zero linear step");
                    args.release ();
                    return NULL;
                  }
                else
                  {
                    clone_info->args[argno].arg_type
                      = SIMD_CLONE_ARG_TYPE_LINEAR_CONSTANT_STEP;
                    clone_info->args[argno].linear_step = tree_to_shwi (step);
                  }
              }
            break;
          }
        case OMP_CLAUSE_UNIFORM:
          {
            tree decl = OMP_CLAUSE_DECL (t);
            int argno = tree_to_uhwi (decl);
            clone_info->args[argno].arg_type
              = SIMD_CLONE_ARG_TYPE_UNIFORM;
            break;
          }
        case OMP_CLAUSE_ALIGNED:
          {
            tree decl = OMP_CLAUSE_DECL (t);
            int argno = tree_to_uhwi (decl);
            clone_info->args[argno].alignment
              = TREE_INT_CST_LOW (OMP_CLAUSE_ALIGNED_ALIGNMENT (t));
            break;
          }
        default:
          break;
        }
    }
  args.release ();
  return clone_info;
}

/* Given a SIMD clone in NODE, calculate the characteristic data
   type and return the coresponding type.  The characteristic data
   type is computed as described in the Intel Vector ABI.  */

static tree
simd_clone_compute_base_data_type (struct cgraph_node *node,
                                   struct cgraph_simd_clone *clone_info)
{
  tree type = integer_type_node;
  tree fndecl = node->decl;

  /* a) For non-void function, the characteristic data type is the
        return type.  */
  if (TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE)
    type = TREE_TYPE (TREE_TYPE (fndecl));

  /* b) If the function has any non-uniform, non-linear parameters,
        then the characteristic data type is the type of the first
        such parameter.  */
  else
    {
      vec<tree> map = simd_clone_vector_of_formal_parm_types (fndecl);
      for (unsigned int i = 0; i < clone_info->nargs; ++i)
        if (clone_info->args[i].arg_type == SIMD_CLONE_ARG_TYPE_VECTOR)
          {
            type = map[i];
            break;
          }
      map.release ();
    }

  /* c) If the characteristic data type determined by a) or b) above
        is struct, union, or class type which is pass-by-value (except
        for the type that maps to the built-in complex data type), the
        characteristic data type is int.  */
  if (RECORD_OR_UNION_TYPE_P (type)
      && !aggregate_value_p (type, NULL)
      && TREE_CODE (type) != COMPLEX_TYPE)
    return integer_type_node;

  /* d) If none of the above three classes is applicable, the
        characteristic data type is int.  */

  return type;

  /* e) For Intel Xeon Phi native and offload compilation, if the
        resulting characteristic data type is 8-bit or 16-bit integer
        data type, the characteristic data type is int.  */
  /* Well, we don't handle Xeon Phi yet.  */
}

static tree
simd_clone_mangle (struct cgraph_node *node,
                   struct cgraph_simd_clone *clone_info)
{
  char vecsize_mangle = clone_info->vecsize_mangle;
  char mask = clone_info->inbranch ? 'M' : 'N';
  unsigned int simdlen = clone_info->simdlen;
  unsigned int n;
  pretty_printer pp;

  gcc_assert (vecsize_mangle && simdlen);

  pp_string (&pp, "_ZGV");
  pp_character (&pp, vecsize_mangle);
  pp_character (&pp, mask);
  pp_decimal_int (&pp, simdlen);

  for (n = 0; n < clone_info->nargs; ++n)
    {
      struct cgraph_simd_clone_arg arg = clone_info->args[n];

      if (arg.arg_type == SIMD_CLONE_ARG_TYPE_UNIFORM)
        pp_character (&pp, 'u');
      else if (arg.arg_type == SIMD_CLONE_ARG_TYPE_LINEAR_CONSTANT_STEP)
        {
          gcc_assert (arg.linear_step != 0);
          pp_character (&pp, 'l');
          if (arg.linear_step > 1)
            pp_unsigned_wide_integer (&pp, arg.linear_step);
          else if (arg.linear_step < 0)
            {
              pp_character (&pp, 'n');
              pp_unsigned_wide_integer (&pp, (-(unsigned HOST_WIDE_INT)
                                              arg.linear_step));
            }
        }
      else if (arg.arg_type == SIMD_CLONE_ARG_TYPE_LINEAR_VARIABLE_STEP)
        {
          pp_character (&pp, 's');
          pp_unsigned_wide_integer (&pp, arg.linear_step);
        }
      else
        pp_character (&pp, 'v');
      if (arg.alignment)
        {
          pp_character (&pp, 'a');
          pp_decimal_int (&pp, arg.alignment);
        }
    }

  pp_underscore (&pp);
  const char *str = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl));
  if (*str == '*')
    ++str;
  pp_string (&pp, str);
  str = pp_formatted_text (&pp);

  /* If there already is a SIMD clone with the same mangled name, don't
     add another one.  This can happen e.g. for
     #pragma omp declare simd
     #pragma omp declare simd simdlen(8)
     int foo (int, int);
     if the simdlen is assumed to be 8 for the first one, etc.  */
  for (struct cgraph_node *clone = node->simd_clones; clone;
       clone = clone->simdclone->next_clone)
    if (strcmp (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (clone->decl)),
                str) == 0)
      return NULL_TREE;

  return get_identifier (str);
}

/* Create a simd clone of OLD_NODE and return it.  */

static struct cgraph_node *
simd_clone_create (struct cgraph_node *old_node)
{
  struct cgraph_node *new_node;
  if (old_node->definition)
    {
      if (!old_node->has_gimple_body_p ())
        return NULL;
      old_node->get_body ();
      new_node = old_node->create_version_clone_with_body (vNULL, NULL, NULL,
                                                           false, NULL, NULL,
                                                           "simdclone");
    }
  else
    {
      tree old_decl = old_node->decl;
      tree new_decl = copy_node (old_node->decl);
      DECL_NAME (new_decl) = clone_function_name (old_decl, "simdclone");
      SET_DECL_ASSEMBLER_NAME (new_decl, DECL_NAME (new_decl));
      SET_DECL_RTL (new_decl, NULL);
      DECL_STATIC_CONSTRUCTOR (new_decl) = 0;
      DECL_STATIC_DESTRUCTOR (new_decl) = 0;
      new_node = old_node->create_version_clone (new_decl, vNULL, NULL);
      symtab->call_cgraph_insertion_hooks (new_node);
    }
  if (new_node == NULL)
    return new_node;

  TREE_PUBLIC (new_node->decl) = TREE_PUBLIC (old_node->decl);

  /* The function cgraph_function_versioning () will force the new
     symbol local.  Undo this, and inherit external visability from
     the old node.  */
  new_node->local.local = old_node->local.local;
  new_node->externally_visible = old_node->externally_visible;

  return new_node;
}

/* Adjust the return type of the given function to its appropriate
   vector counterpart.  Returns a simd array to be used throughout the
   function as a return value.  */

static tree
simd_clone_adjust_return_type (struct cgraph_node *node)
{
  tree fndecl = node->decl;
  tree orig_rettype = TREE_TYPE (TREE_TYPE (fndecl));
  unsigned int veclen;
  tree t;

  /* Adjust the function return type.  */
  if (orig_rettype == void_type_node)
    return NULL_TREE;
  TREE_TYPE (fndecl) = build_distinct_type_copy (TREE_TYPE (fndecl));
  t = TREE_TYPE (TREE_TYPE (fndecl));
  if (INTEGRAL_TYPE_P (t) || POINTER_TYPE_P (t))
    veclen = node->simdclone->vecsize_int;
  else
    veclen = node->simdclone->vecsize_float;
  veclen /= GET_MODE_BITSIZE (TYPE_MODE (t));
  if (veclen > node->simdclone->simdlen)
    veclen = node->simdclone->simdlen;
  if (POINTER_TYPE_P (t))
    t = pointer_sized_int_node;
  if (veclen == node->simdclone->simdlen)
    t = build_vector_type (t, node->simdclone->simdlen);
  else
    {
      t = build_vector_type (t, veclen);
      t = build_array_type_nelts (t, node->simdclone->simdlen / veclen);
    }
  TREE_TYPE (TREE_TYPE (fndecl)) = t;
  if (!node->definition)
    return NULL_TREE;

  t = DECL_RESULT (fndecl);
  /* Adjust the DECL_RESULT.  */
  gcc_assert (TREE_TYPE (t) != void_type_node);
  TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (fndecl));
  relayout_decl (t);

  tree atype = build_array_type_nelts (orig_rettype,
                                       node->simdclone->simdlen);
  if (veclen != node->simdclone->simdlen)
    return build1 (VIEW_CONVERT_EXPR, atype, t);

  /* Set up a SIMD array to use as the return value.  */
  tree retval = create_tmp_var_raw (atype, "retval");
  gimple_add_tmp_var (retval);
  return retval;
}

/* Each vector argument has a corresponding array to be used locally
   as part of the eventual loop.  Create such temporary array and
   return it.

   PREFIX is the prefix to be used for the temporary.

   TYPE is the inner element type.

   SIMDLEN is the number of elements.  */

static tree
create_tmp_simd_array (const char *prefix, tree type, int simdlen)
{
  tree atype = build_array_type_nelts (type, simdlen);
  tree avar = create_tmp_var_raw (atype, prefix);
  gimple_add_tmp_var (avar);
  return avar;
}

/* Modify the function argument types to their corresponding vector
   counterparts if appropriate.  Also, create one array for each simd
   argument to be used locally when using the function arguments as
   part of the loop.

   NODE is the function whose arguments are to be adjusted.

   Returns an adjustment vector that will be filled describing how the
   argument types will be adjusted.  */

static ipa_parm_adjustment_vec
simd_clone_adjust_argument_types (struct cgraph_node *node)
{
  vec<tree> args;
  ipa_parm_adjustment_vec adjustments;

  if (node->definition)
    args = ipa_get_vector_of_formal_parms (node->decl);
  else
    args = simd_clone_vector_of_formal_parm_types (node->decl);
  adjustments.create (args.length ());
  unsigned i, j, veclen;
  struct ipa_parm_adjustment adj;
  for (i = 0; i < node->simdclone->nargs; ++i)
    {
      memset (&adj, 0, sizeof (adj));
      tree parm = args[i];
      tree parm_type = node->definition ? TREE_TYPE (parm) : parm;
      adj.base_index = i;
      adj.base = parm;

      node->simdclone->args[i].orig_arg = node->definition ? parm : NULL_TREE;
      node->simdclone->args[i].orig_type = parm_type;

      if (node->simdclone->args[i].arg_type != SIMD_CLONE_ARG_TYPE_VECTOR)
        {
          /* No adjustment necessary for scalar arguments.  */
          adj.op = IPA_PARM_OP_COPY;
        }
      else
        {
          if (INTEGRAL_TYPE_P (parm_type) || POINTER_TYPE_P (parm_type))
            veclen = node->simdclone->vecsize_int;
          else
            veclen = node->simdclone->vecsize_float;
          veclen /= GET_MODE_BITSIZE (TYPE_MODE (parm_type));
          if (veclen > node->simdclone->simdlen)
            veclen = node->simdclone->simdlen;
          adj.arg_prefix = "simd";
          if (POINTER_TYPE_P (parm_type))
            adj.type = build_vector_type (pointer_sized_int_node, veclen);
          else
            adj.type = build_vector_type (parm_type, veclen);
          node->simdclone->args[i].vector_type = adj.type;
          for (j = veclen; j < node->simdclone->simdlen; j += veclen)
            {
              adjustments.safe_push (adj);
              if (j == veclen)
                {
                  memset (&adj, 0, sizeof (adj));
                  adj.op = IPA_PARM_OP_NEW;
                  adj.arg_prefix = "simd";
                  adj.base_index = i;
                  adj.type = node->simdclone->args[i].vector_type;
                }
            }

          if (node->definition)
            node->simdclone->args[i].simd_array
              = create_tmp_simd_array (IDENTIFIER_POINTER (DECL_NAME (parm)),
                                       parm_type, node->simdclone->simdlen);
        }
      adjustments.safe_push (adj);
    }

  if (node->simdclone->inbranch)
    {
      tree base_type
        = simd_clone_compute_base_data_type (node->simdclone->origin,
                                             node->simdclone);

      memset (&adj, 0, sizeof (adj));
      adj.op = IPA_PARM_OP_NEW;
      adj.arg_prefix = "mask";

      adj.base_index = i;
      if (INTEGRAL_TYPE_P (base_type) || POINTER_TYPE_P (base_type))
        veclen = node->simdclone->vecsize_int;
      else
        veclen = node->simdclone->vecsize_float;
      veclen /= GET_MODE_BITSIZE (TYPE_MODE (base_type));
      if (veclen > node->simdclone->simdlen)
        veclen = node->simdclone->simdlen;
      if (POINTER_TYPE_P (base_type))
        adj.type = build_vector_type (pointer_sized_int_node, veclen);
      else
        adj.type = build_vector_type (base_type, veclen);
      adjustments.safe_push (adj);

      for (j = veclen; j < node->simdclone->simdlen; j += veclen)
        adjustments.safe_push (adj);

      /* We have previously allocated one extra entry for the mask.  Use
         it and fill it.  */
      struct cgraph_simd_clone *sc = node->simdclone;
      sc->nargs++;
      if (node->definition)
        {
          sc->args[i].orig_arg
            = build_decl (UNKNOWN_LOCATION, PARM_DECL, NULL, base_type);
          sc->args[i].simd_array
            = create_tmp_simd_array ("mask", base_type, sc->simdlen);
        }
      sc->args[i].orig_type = base_type;
      sc->args[i].arg_type = SIMD_CLONE_ARG_TYPE_MASK;
    }

  if (node->definition)
    ipa_modify_formal_parameters (node->decl, adjustments);
  else
    {
      tree new_arg_types = NULL_TREE, new_reversed;
      bool last_parm_void = false;
      if (args.length () > 0 && args.last () == void_type_node)
        last_parm_void = true;

      gcc_assert (TYPE_ARG_TYPES (TREE_TYPE (node->decl)));
      j = adjustments.length ();
      for (i = 0; i < j; i++)
        {
          struct ipa_parm_adjustment *adj = &adjustments[i];
          tree ptype;
          if (adj->op == IPA_PARM_OP_COPY)
            ptype = args[adj->base_index];
          else
            ptype = adj->type;
          new_arg_types = tree_cons (NULL_TREE, ptype, new_arg_types);
        }
      new_reversed = nreverse (new_arg_types);
      if (last_parm_void)
        {
          if (new_reversed)
            TREE_CHAIN (new_arg_types) = void_list_node;
          else
            new_reversed = void_list_node;
        }

      tree new_type = build_distinct_type_copy (TREE_TYPE (node->decl));
      TYPE_ARG_TYPES (new_type) = new_reversed;
      TREE_TYPE (node->decl) = new_type;

      adjustments.release ();
    }
  args.release ();
  return adjustments;
}

/* Initialize and copy the function arguments in NODE to their
   corresponding local simd arrays.  Returns a fresh gimple_seq with
   the instruction sequence generated.  */

static gimple_seq
simd_clone_init_simd_arrays (struct cgraph_node *node,
                             ipa_parm_adjustment_vec adjustments)
{
  gimple_seq seq = NULL;
  unsigned i = 0, j = 0, k;

  for (tree arg = DECL_ARGUMENTS (node->decl);
       arg;
       arg = DECL_CHAIN (arg), i++, j++)
    {
      if (adjustments[j].op == IPA_PARM_OP_COPY)
        continue;

      node->simdclone->args[i].vector_arg = arg;

      tree array = node->simdclone->args[i].simd_array;
      if (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg)) == node->simdclone->simdlen)
        {
          tree ptype = build_pointer_type (TREE_TYPE (TREE_TYPE (array)));
          tree ptr = build_fold_addr_expr (array);
          tree t = build2 (MEM_REF, TREE_TYPE (arg), ptr,
                           build_int_cst (ptype, 0));
          t = build2 (MODIFY_EXPR, TREE_TYPE (t), t, arg);
          gimplify_and_add (t, &seq);
        }
      else
        {
          unsigned int simdlen = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg));
          tree ptype = build_pointer_type (TREE_TYPE (TREE_TYPE (array)));
          for (k = 0; k < node->simdclone->simdlen; k += simdlen)
            {
              tree ptr = build_fold_addr_expr (array);
              int elemsize;
              if (k)
                {
                  arg = DECL_CHAIN (arg);
                  j++;
                }
              elemsize
                = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (arg))));
              tree t = build2 (MEM_REF, TREE_TYPE (arg), ptr,
                               build_int_cst (ptype, k * elemsize));
              t = build2 (MODIFY_EXPR, TREE_TYPE (t), t, arg);
              gimplify_and_add (t, &seq);
            }
        }
    }
  return seq;
}

/* Callback info for ipa_simd_modify_stmt_ops below.  */

struct modify_stmt_info {
  ipa_parm_adjustment_vec adjustments;
  gimple stmt;
  /* True if the parent statement was modified by
     ipa_simd_modify_stmt_ops.  */
  bool modified;
};

/* Callback for walk_gimple_op.

   Adjust operands from a given statement as specified in the
   adjustments vector in the callback data.  */

static tree
ipa_simd_modify_stmt_ops (tree *tp, int *walk_subtrees, void *data)
{
  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
  struct modify_stmt_info *info = (struct modify_stmt_info *) wi->info;
  tree *orig_tp = tp;
  if (TREE_CODE (*tp) == ADDR_EXPR)
    tp = &TREE_OPERAND (*tp, 0);
  struct ipa_parm_adjustment *cand = NULL;
  if (TREE_CODE (*tp) == PARM_DECL)
    cand = ipa_get_adjustment_candidate (&tp, NULL, info->adjustments, true);
  else
    {
      if (TYPE_P (*tp))
        *walk_subtrees = 0;
    }

  tree repl = NULL_TREE;
  if (cand)
    repl = unshare_expr (cand->new_decl);
  else
    {
      if (tp != orig_tp)
        {
          *walk_subtrees = 0;
          bool modified = info->modified;
          info->modified = false;
          walk_tree (tp, ipa_simd_modify_stmt_ops, wi, wi->pset);
          if (!info->modified)
            {
              info->modified = modified;
              return NULL_TREE;
            }
          info->modified = modified;
          repl = *tp;
        }
      else
        return NULL_TREE;
    }

  if (tp != orig_tp)
    {
      repl = build_fold_addr_expr (repl);
      gimple stmt;
      if (is_gimple_debug (info->stmt))
        {
          tree vexpr = make_node (DEBUG_EXPR_DECL);
          stmt = gimple_build_debug_source_bind (vexpr, repl, NULL);
          DECL_ARTIFICIAL (vexpr) = 1;
          TREE_TYPE (vexpr) = TREE_TYPE (repl);
          DECL_MODE (vexpr) = TYPE_MODE (TREE_TYPE (repl));
          repl = vexpr;
        }
      else
        {
          stmt = gimple_build_assign (make_ssa_name (TREE_TYPE (repl)), repl);
          repl = gimple_assign_lhs (stmt);
        }
      gimple_stmt_iterator gsi = gsi_for_stmt (info->stmt);
      gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
      *orig_tp = repl;
    }
  else if (!useless_type_conversion_p (TREE_TYPE (*tp), TREE_TYPE (repl)))
    {
      tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*tp), repl);
      *tp = vce;
    }
  else
    *tp = repl;

  info->modified = true;
  return NULL_TREE;
}

/* Traverse the function body and perform all modifications as
   described in ADJUSTMENTS.  At function return, ADJUSTMENTS will be
   modified such that the replacement/reduction value will now be an
   offset into the corresponding simd_array.

   This function will replace all function argument uses with their
   corresponding simd array elements, and ajust the return values
   accordingly.  */

static void
ipa_simd_modify_function_body (struct cgraph_node *node,
                               ipa_parm_adjustment_vec adjustments,
                               tree retval_array, tree iter)
{
  basic_block bb;
  unsigned int i, j, l;

  /* Re-use the adjustments array, but this time use it to replace
     every function argument use to an offset into the corresponding
     simd_array.  */
  for (i = 0, j = 0; i < node->simdclone->nargs; ++i, ++j)
    {
      if (!node->simdclone->args[i].vector_arg)
        continue;

      tree basetype = TREE_TYPE (node->simdclone->args[i].orig_arg);
      tree vectype = TREE_TYPE (node->simdclone->args[i].vector_arg);
      adjustments[j].new_decl
        = build4 (ARRAY_REF,
                  basetype,
                  node->simdclone->args[i].simd_array,
                  iter,
                  NULL_TREE, NULL_TREE);
      if (adjustments[j].op == IPA_PARM_OP_NONE
          && TYPE_VECTOR_SUBPARTS (vectype) < node->simdclone->simdlen)
        j += node->simdclone->simdlen / TYPE_VECTOR_SUBPARTS (vectype) - 1;
    }

  l = adjustments.length ();
  for (i = 1; i < num_ssa_names; i++)
    {
      tree name = ssa_name (i);
      if (name
          && SSA_NAME_VAR (name)
          && TREE_CODE (SSA_NAME_VAR (name)) == PARM_DECL)
        {
          for (j = 0; j < l; j++)
            if (SSA_NAME_VAR (name) == adjustments[j].base
                && adjustments[j].new_decl)
              {
                tree base_var;
                if (adjustments[j].new_ssa_base == NULL_TREE)
                  {
                    base_var
                      = copy_var_decl (adjustments[j].base,
                                       DECL_NAME (adjustments[j].base),
                                       TREE_TYPE (adjustments[j].base));
                    adjustments[j].new_ssa_base = base_var;
                  }
                else
                  base_var = adjustments[j].new_ssa_base;
                if (SSA_NAME_IS_DEFAULT_DEF (name))
                  {
                    bb = single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun));
                    gimple_stmt_iterator gsi = gsi_after_labels (bb);
                    tree new_decl = unshare_expr (adjustments[j].new_decl);
                    set_ssa_default_def (cfun, adjustments[j].base, NULL_TREE);
                    SET_SSA_NAME_VAR_OR_IDENTIFIER (name, base_var);
                    SSA_NAME_IS_DEFAULT_DEF (name) = 0;
                    gimple stmt = gimple_build_assign (name, new_decl);
                    gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
                  }
                else
                  SET_SSA_NAME_VAR_OR_IDENTIFIER (name, base_var);
              }
        }
    }

  struct modify_stmt_info info;
  info.adjustments = adjustments;

  FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
    {
      gimple_stmt_iterator gsi;

      gsi = gsi_start_bb (bb);
      while (!gsi_end_p (gsi))
        {
          gimple stmt = gsi_stmt (gsi);
          info.stmt = stmt;
          struct walk_stmt_info wi;

          memset (&wi, 0, sizeof (wi));
          info.modified = false;
          wi.info = &info;
          walk_gimple_op (stmt, ipa_simd_modify_stmt_ops, &wi);

          if (greturn *return_stmt = dyn_cast <greturn *> (stmt))
            {
              tree retval = gimple_return_retval (return_stmt);
              if (!retval)
                {
                  gsi_remove (&gsi, true);
                  continue;
                }

              /* Replace `return foo' with `retval_array[iter] = foo'.  */
              tree ref = build4 (ARRAY_REF, TREE_TYPE (retval),
                                 retval_array, iter, NULL, NULL);
              stmt = gimple_build_assign (ref, retval);
              gsi_replace (&gsi, stmt, true);
              info.modified = true;
            }

          if (info.modified)
            {
              update_stmt (stmt);
              if (maybe_clean_eh_stmt (stmt))
                gimple_purge_dead_eh_edges (gimple_bb (stmt));
            }
          gsi_next (&gsi);
        }
    }
}

/* Adjust the argument types in NODE to their appropriate vector
   counterparts.  */

static void
simd_clone_adjust (struct cgraph_node *node)
{
  push_cfun (DECL_STRUCT_FUNCTION (node->decl));

  targetm.simd_clone.adjust (node);

  tree retval = simd_clone_adjust_return_type (node);
  ipa_parm_adjustment_vec adjustments
    = simd_clone_adjust_argument_types (node);

  push_gimplify_context ();

  gimple_seq seq = simd_clone_init_simd_arrays (node, adjustments);

  /* Adjust all uses of vector arguments accordingly.  Adjust all
     return values accordingly.  */
  tree iter = create_tmp_var (unsigned_type_node, "iter");
  tree iter1 = make_ssa_name (iter);
  tree iter2 = make_ssa_name (iter);
  ipa_simd_modify_function_body (node, adjustments, retval, iter1);

  /* Initialize the iteration variable.  */
  basic_block entry_bb = single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun));
  basic_block body_bb = split_block_after_labels (entry_bb)->dest;
  gimple_stmt_iterator gsi = gsi_after_labels (entry_bb);
  /* Insert the SIMD array and iv initialization at function
     entry.  */
  gsi_insert_seq_before (&gsi, seq, GSI_NEW_STMT);

  pop_gimplify_context (NULL);

  /* Create a new BB right before the original exit BB, to hold the
     iteration increment and the condition/branch.  */
  basic_block orig_exit = EDGE_PRED (EXIT_BLOCK_PTR_FOR_FN (cfun), 0)->src;
  basic_block incr_bb = create_empty_bb (orig_exit);
  add_bb_to_loop (incr_bb, body_bb->loop_father);
  /* The succ of orig_exit was EXIT_BLOCK_PTR_FOR_FN (cfun), with an empty
     flag.  Set it now to be a FALLTHRU_EDGE.  */
  gcc_assert (EDGE_COUNT (orig_exit->succs) == 1);
  EDGE_SUCC (orig_exit, 0)->flags |= EDGE_FALLTHRU;
  for (unsigned i = 0;
       i < EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); ++i)
    {
      edge e = EDGE_PRED (EXIT_BLOCK_PTR_FOR_FN (cfun), i);
      redirect_edge_succ (e, incr_bb);
    }
  edge e = make_edge (incr_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
  e->probability = REG_BR_PROB_BASE;
  gsi = gsi_last_bb (incr_bb);
  gimple g = gimple_build_assign (iter2, PLUS_EXPR, iter1,
                                  build_int_cst (unsigned_type_node, 1));
  gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);

  /* Mostly annotate the loop for the vectorizer (the rest is done below).  */
  struct loop *loop = alloc_loop ();
  cfun->has_force_vectorize_loops = true;
  loop->safelen = node->simdclone->simdlen;
  loop->force_vectorize = true;
  loop->header = body_bb;

  /* Branch around the body if the mask applies.  */
  if (node->simdclone->inbranch)
    {
      gimple_stmt_iterator gsi = gsi_last_bb (loop->header);
      tree mask_array
        = node->simdclone->args[node->simdclone->nargs - 1].simd_array;
      tree mask = make_ssa_name (TREE_TYPE (TREE_TYPE (mask_array)));
      tree aref = build4 (ARRAY_REF,
                          TREE_TYPE (TREE_TYPE (mask_array)),
                          mask_array, iter1,
                          NULL, NULL);
      g = gimple_build_assign (mask, aref);
      gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
      int bitsize = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (aref)));
      if (!INTEGRAL_TYPE_P (TREE_TYPE (aref)))
        {
          aref = build1 (VIEW_CONVERT_EXPR,
                         build_nonstandard_integer_type (bitsize, 0), mask);
          mask = make_ssa_name (TREE_TYPE (aref));
          g = gimple_build_assign (mask, aref);
          gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
        }

      g = gimple_build_cond (EQ_EXPR, mask, build_zero_cst (TREE_TYPE (mask)),
                             NULL, NULL);
      gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
      make_edge (loop->header, incr_bb, EDGE_TRUE_VALUE);
      FALLTHRU_EDGE (loop->header)->flags = EDGE_FALSE_VALUE;
    }

  /* Generate the condition.  */
  g = gimple_build_cond (LT_EXPR,
                         iter2,
                         build_int_cst (unsigned_type_node,
                                        node->simdclone->simdlen),
                         NULL, NULL);
  gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
  e = split_block (incr_bb, gsi_stmt (gsi));
  basic_block latch_bb = e->dest;
  basic_block new_exit_bb;
  new_exit_bb = split_block_after_labels (latch_bb)->dest;
  loop->latch = latch_bb;

  redirect_edge_succ (FALLTHRU_EDGE (latch_bb), body_bb);

  make_edge (incr_bb, new_exit_bb, EDGE_FALSE_VALUE);
  /* The successor of incr_bb is already pointing to latch_bb; just
     change the flags.
     make_edge (incr_bb, latch_bb, EDGE_TRUE_VALUE);  */
  FALLTHRU_EDGE (incr_bb)->flags = EDGE_TRUE_VALUE;

  gphi *phi = create_phi_node (iter1, body_bb);
  edge preheader_edge = find_edge (entry_bb, body_bb);
  edge latch_edge = single_succ_edge (latch_bb);
  add_phi_arg (phi, build_zero_cst (unsigned_type_node), preheader_edge,
               UNKNOWN_LOCATION);
  add_phi_arg (phi, iter2, latch_edge, UNKNOWN_LOCATION);

  /* Generate the new return.  */
  gsi = gsi_last_bb (new_exit_bb);
  if (retval
      && TREE_CODE (retval) == VIEW_CONVERT_EXPR
      && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
    retval = TREE_OPERAND (retval, 0);
  else if (retval)
    {
      retval = build1 (VIEW_CONVERT_EXPR,
                       TREE_TYPE (TREE_TYPE (node->decl)),
                       retval);
      retval = force_gimple_operand_gsi (&gsi, retval, true, NULL,
                                         false, GSI_CONTINUE_LINKING);
    }
  g = gimple_build_return (retval);
  gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);

  /* Handle aligned clauses by replacing default defs of the aligned
     uniform args with __builtin_assume_aligned (arg_N(D), alignment)
     lhs.  Handle linear by adding PHIs.  */
  for (unsigned i = 0; i < node->simdclone->nargs; i++)
    if (node->simdclone->args[i].arg_type == SIMD_CLONE_ARG_TYPE_UNIFORM
        && (TREE_ADDRESSABLE (node->simdclone->args[i].orig_arg)
            || !is_gimple_reg_type
                        (TREE_TYPE (node->simdclone->args[i].orig_arg))))
      {
        tree orig_arg = node->simdclone->args[i].orig_arg;
        if (is_gimple_reg_type (TREE_TYPE (orig_arg)))
          iter1 = make_ssa_name (TREE_TYPE (orig_arg));
        else
          {
            iter1 = create_tmp_var_raw (TREE_TYPE (orig_arg));
            gimple_add_tmp_var (iter1);
          }
        gsi = gsi_after_labels (entry_bb);
        g = gimple_build_assign (iter1, orig_arg);
        gsi_insert_before (&gsi, g, GSI_NEW_STMT);
        gsi = gsi_after_labels (body_bb);
        g = gimple_build_assign (orig_arg, iter1);
        gsi_insert_before (&gsi, g, GSI_NEW_STMT);
      }
    else if (node->simdclone->args[i].arg_type == SIMD_CLONE_ARG_TYPE_UNIFORM
             && DECL_BY_REFERENCE (node->simdclone->args[i].orig_arg)
             && TREE_CODE (TREE_TYPE (node->simdclone->args[i].orig_arg))
                == REFERENCE_TYPE
             && TREE_ADDRESSABLE
                  (TREE_TYPE (TREE_TYPE (node->simdclone->args[i].orig_arg))))
      {
        tree orig_arg = node->simdclone->args[i].orig_arg;
        tree def = ssa_default_def (cfun, orig_arg);
        if (def && !has_zero_uses (def))
          {
            iter1 = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (orig_arg)));
            gimple_add_tmp_var (iter1);
            gsi = gsi_after_labels (entry_bb);
            g = gimple_build_assign (iter1, build_simple_mem_ref (def));
            gsi_insert_before (&gsi, g, GSI_NEW_STMT);
            gsi = gsi_after_labels (body_bb);
            g = gimple_build_assign (build_simple_mem_ref (def), iter1);
            gsi_insert_before (&gsi, g, GSI_NEW_STMT);
          }
      }
    else if (node->simdclone->args[i].alignment
             && node->simdclone->args[i].arg_type
                == SIMD_CLONE_ARG_TYPE_UNIFORM
             && (node->simdclone->args[i].alignment
                 & (node->simdclone->args[i].alignment - 1)) == 0
             && TREE_CODE (TREE_TYPE (node->simdclone->args[i].orig_arg))
                == POINTER_TYPE)
      {
        unsigned int alignment = node->simdclone->args[i].alignment;
        tree orig_arg = node->simdclone->args[i].orig_arg;
        tree def = ssa_default_def (cfun, orig_arg);
        if (def && !has_zero_uses (def))
          {
            tree fn = builtin_decl_explicit (BUILT_IN_ASSUME_ALIGNED);
            gimple_seq seq = NULL;
            bool need_cvt = false;
            gcall *call
              = gimple_build_call (fn, 2, def, size_int (alignment));
            g = call;
            if (!useless_type_conversion_p (TREE_TYPE (orig_arg),
                                            ptr_type_node))
              need_cvt = true;
            tree t = make_ssa_name (need_cvt ? ptr_type_node : orig_arg);
            gimple_call_set_lhs (g, t);
            gimple_seq_add_stmt_without_update (&seq, g);
            if (need_cvt)
              {
                t = make_ssa_name (orig_arg);
                g = gimple_build_assign (t, NOP_EXPR, gimple_call_lhs (g));
                gimple_seq_add_stmt_without_update (&seq, g);
              }
            gsi_insert_seq_on_edge_immediate
              (single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)), seq);

            entry_bb = single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun));
            int freq = compute_call_stmt_bb_frequency (current_function_decl,
                                                       entry_bb);
            node->create_edge (cgraph_node::get_create (fn),
                               call, entry_bb->count, freq);

            imm_use_iterator iter;
            use_operand_p use_p;
            gimple use_stmt;
            tree repl = gimple_get_lhs (g);
            FOR_EACH_IMM_USE_STMT (use_stmt, iter, def)
              if (is_gimple_debug (use_stmt) || use_stmt == call)
                continue;
              else
                FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
                  SET_USE (use_p, repl);
          }
      }
    else if (node->simdclone->args[i].arg_type
             == SIMD_CLONE_ARG_TYPE_LINEAR_CONSTANT_STEP)
      {
        tree orig_arg = node->simdclone->args[i].orig_arg;
        gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (orig_arg))
                    || POINTER_TYPE_P (TREE_TYPE (orig_arg)));
        tree def = NULL_TREE;
        if (TREE_ADDRESSABLE (orig_arg))
          {
            def = make_ssa_name (TREE_TYPE (orig_arg));
            iter1 = make_ssa_name (TREE_TYPE (orig_arg));
            iter2 = make_ssa_name (TREE_TYPE (orig_arg));
            gsi = gsi_after_labels (entry_bb);
            g = gimple_build_assign (def, orig_arg);
            gsi_insert_before (&gsi, g, GSI_NEW_STMT);
          }
        else
          {
            def = ssa_default_def (cfun, orig_arg);
            if (!def || has_zero_uses (def))
              def = NULL_TREE;
            else
              {
                iter1 = make_ssa_name (orig_arg);
                iter2 = make_ssa_name (orig_arg);
              }
          }
        if (def)
          {
            phi = create_phi_node (iter1, body_bb);
            add_phi_arg (phi, def, preheader_edge, UNKNOWN_LOCATION);
            add_phi_arg (phi, iter2, latch_edge, UNKNOWN_LOCATION);
            enum tree_code code = INTEGRAL_TYPE_P (TREE_TYPE (orig_arg))
                                  ? PLUS_EXPR : POINTER_PLUS_EXPR;
            tree addtype = INTEGRAL_TYPE_P (TREE_TYPE (orig_arg))
                           ? TREE_TYPE (orig_arg) : sizetype;
            tree addcst
              = build_int_cst (addtype, node->simdclone->args[i].linear_step);
            g = gimple_build_assign (iter2, code, iter1, addcst);
            gsi = gsi_last_bb (incr_bb);
            gsi_insert_before (&gsi, g, GSI_SAME_STMT);

            imm_use_iterator iter;
            use_operand_p use_p;
            gimple use_stmt;
            if (TREE_ADDRESSABLE (orig_arg))
              {
                gsi = gsi_after_labels (body_bb);
                g = gimple_build_assign (orig_arg, iter1);
                gsi_insert_before (&gsi, g, GSI_NEW_STMT);
              }
            else
              FOR_EACH_IMM_USE_STMT (use_stmt, iter, def)
                if (use_stmt == phi)
                  continue;
                else
                  FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
                    SET_USE (use_p, iter1);
          }
      }

  calculate_dominance_info (CDI_DOMINATORS);
  add_loop (loop, loop->header->loop_father);
  update_ssa (TODO_update_ssa);

  pop_cfun ();
}

/* If the function in NODE is tagged as an elemental SIMD function,
   create the appropriate SIMD clones.  */

static void
expand_simd_clones (struct cgraph_node *node)
{
  tree attr = lookup_attribute ("omp declare simd",
                                DECL_ATTRIBUTES (node->decl));
  if (attr == NULL_TREE
      || node->global.inlined_to
      || lookup_attribute ("noclone", DECL_ATTRIBUTES (node->decl)))
    return;

  /* Ignore
     #pragma omp declare simd
     extern int foo ();
     in C, there we don't know the argument types at all.  */
  if (!node->definition
      && TYPE_ARG_TYPES (TREE_TYPE (node->decl)) == NULL_TREE)
    return;

  do
    {
      /* Start with parsing the "omp declare simd" attribute(s).  */
      bool inbranch_clause_specified;
      struct cgraph_simd_clone *clone_info
        = simd_clone_clauses_extract (node, TREE_VALUE (attr),
                                      &inbranch_clause_specified);
      if (clone_info == NULL)
        continue;

      int orig_simdlen = clone_info->simdlen;
      tree base_type = simd_clone_compute_base_data_type (node, clone_info);
      /* The target can return 0 (no simd clones should be created),
         1 (just one ISA of simd clones should be created) or higher
         count of ISA variants.  In that case, clone_info is initialized
         for the first ISA variant.  */
      int count
        = targetm.simd_clone.compute_vecsize_and_simdlen (node, clone_info,
                                                          base_type, 0);
      if (count == 0)
        continue;

      /* Loop over all COUNT ISA variants, and if !INBRANCH_CLAUSE_SPECIFIED,
         also create one inbranch and one !inbranch clone of it.  */
      for (int i = 0; i < count * 2; i++)
        {
          struct cgraph_simd_clone *clone = clone_info;
          if (inbranch_clause_specified && (i & 1) != 0)
            continue;

          if (i != 0)
            {
              clone = simd_clone_struct_alloc (clone_info->nargs
                                               + ((i & 1) != 0));
              simd_clone_struct_copy (clone, clone_info);
              /* Undo changes targetm.simd_clone.compute_vecsize_and_simdlen
                 and simd_clone_adjust_argument_types did to the first
                 clone's info.  */
              clone->nargs -= clone_info->inbranch;
              clone->simdlen = orig_simdlen;
              /* And call the target hook again to get the right ISA.  */
              targetm.simd_clone.compute_vecsize_and_simdlen (node, clone,
                                                              base_type,
                                                              i / 2);
              if ((i & 1) != 0)
                clone->inbranch = 1;
            }

          /* simd_clone_mangle might fail if such a clone has been created
             already.  */
          tree id = simd_clone_mangle (node, clone);
          if (id == NULL_TREE)
            continue;

          /* Only when we are sure we want to create the clone actually
             clone the function (or definitions) or create another
             extern FUNCTION_DECL (for prototypes without definitions).  */
          struct cgraph_node *n = simd_clone_create (node);
          if (n == NULL)
            continue;

          n->simdclone = clone;
          clone->origin = node;
          clone->next_clone = NULL;
          if (node->simd_clones == NULL)
            {
              clone->prev_clone = n;
              node->simd_clones = n;
            }
          else
            {
              clone->prev_clone = node->simd_clones->simdclone->prev_clone;
              clone->prev_clone->simdclone->next_clone = n;
              node->simd_clones->simdclone->prev_clone = n;
            }
          symtab->change_decl_assembler_name (n->decl, id);
          /* And finally adjust the return type, parameters and for
             definitions also function body.  */
          if (node->definition)
            simd_clone_adjust (n);
          else
            {
              simd_clone_adjust_return_type (n);
              simd_clone_adjust_argument_types (n);
            }
        }
    }
  while ((attr = lookup_attribute ("omp declare simd", TREE_CHAIN (attr))));
}

/* Entry point for IPA simd clone creation pass.  */

static unsigned int
ipa_omp_simd_clone (void)
{
  struct cgraph_node *node;
  FOR_EACH_FUNCTION (node)
    expand_simd_clones (node);
  return 0;
}

namespace {

const pass_data pass_data_omp_simd_clone =
{
  SIMPLE_IPA_PASS,              /* type */
  "simdclone",                  /* name */
  OPTGROUP_NONE,                /* optinfo_flags */
  TV_NONE,                      /* tv_id */
  ( PROP_ssa | PROP_cfg ),      /* properties_required */
  0,                            /* properties_provided */
  0,                            /* properties_destroyed */
  0,                            /* todo_flags_start */
  0,                            /* todo_flags_finish */
};

class pass_omp_simd_clone : public simple_ipa_opt_pass
{
public:
  pass_omp_simd_clone(gcc::context *ctxt)
    : simple_ipa_opt_pass(pass_data_omp_simd_clone, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *);
  virtual unsigned int execute (function *) { return ipa_omp_simd_clone (); }
};

bool
pass_omp_simd_clone::gate (function *)
{
  return ((flag_openmp || flag_openmp_simd
           || flag_cilkplus
           || (in_lto_p && !flag_wpa))
          && (targetm.simd_clone.compute_vecsize_and_simdlen != NULL));
}

} // anon namespace

simple_ipa_opt_pass *
make_pass_omp_simd_clone (gcc::context *ctxt)
{
  return new pass_omp_simd_clone (ctxt);
}

/* Helper function for omp_finish_file routine.  Takes decls from V_DECLS and
   adds their addresses and sizes to constructor-vector V_CTOR.  */
static void
add_decls_addresses_to_decl_constructor (vec<tree, va_gc> *v_decls,
                                         vec<constructor_elt, va_gc> *v_ctor)
{
  unsigned len = vec_safe_length (v_decls);
  for (unsigned i = 0; i < len; i++)
    {
      tree it = (*v_decls)[i];
      bool is_function = TREE_CODE (it) != VAR_DECL;

      CONSTRUCTOR_APPEND_ELT (v_ctor, NULL_TREE, build_fold_addr_expr (it));
      if (!is_function)
        CONSTRUCTOR_APPEND_ELT (v_ctor, NULL_TREE,
                                fold_convert (const_ptr_type_node,
                                              DECL_SIZE_UNIT (it)));
    }
}

/* Create new symbols containing (address, size) pairs for global variables,
   marked with "omp declare target" attribute, as well as addresses for the
   functions, which are outlined offloading regions.  */
void
omp_finish_file (void)
{
  unsigned num_funcs = vec_safe_length (offload_funcs);
  unsigned num_vars = vec_safe_length (offload_vars);

  if (num_funcs == 0 && num_vars == 0)
    return;

  if (targetm_common.have_named_sections)
    {
      vec<constructor_elt, va_gc> *v_f, *v_v;
      vec_alloc (v_f, num_funcs);
      vec_alloc (v_v, num_vars * 2);

      add_decls_addresses_to_decl_constructor (offload_funcs, v_f);
      add_decls_addresses_to_decl_constructor (offload_vars, v_v);

      tree vars_decl_type = build_array_type_nelts (pointer_sized_int_node,
                                                    num_vars * 2);
      tree funcs_decl_type = build_array_type_nelts (pointer_sized_int_node,
                                                     num_funcs);
      TYPE_ALIGN (vars_decl_type) = TYPE_ALIGN (pointer_sized_int_node);
      TYPE_ALIGN (funcs_decl_type) = TYPE_ALIGN (pointer_sized_int_node);
      tree ctor_v = build_constructor (vars_decl_type, v_v);
      tree ctor_f = build_constructor (funcs_decl_type, v_f);
      TREE_CONSTANT (ctor_v) = TREE_CONSTANT (ctor_f) = 1;
      TREE_STATIC (ctor_v) = TREE_STATIC (ctor_f) = 1;
      tree funcs_decl = build_decl (UNKNOWN_LOCATION, VAR_DECL,
                                    get_identifier (".offload_func_table"),
                                    funcs_decl_type);
      tree vars_decl = build_decl (UNKNOWN_LOCATION, VAR_DECL,
                                   get_identifier (".offload_var_table"),
                                   vars_decl_type);
      TREE_STATIC (funcs_decl) = TREE_STATIC (vars_decl) = 1;
      /* Do not align tables more than TYPE_ALIGN (pointer_sized_int_node),
         otherwise a joint table in a binary will contain padding between
         tables from multiple object files.  */
      DECL_USER_ALIGN (funcs_decl) = DECL_USER_ALIGN (vars_decl) = 1;
      DECL_ALIGN (funcs_decl) = TYPE_ALIGN (funcs_decl_type);
      DECL_ALIGN (vars_decl) = TYPE_ALIGN (vars_decl_type);
      DECL_INITIAL (funcs_decl) = ctor_f;
      DECL_INITIAL (vars_decl) = ctor_v;
      set_decl_section_name (funcs_decl, OFFLOAD_FUNC_TABLE_SECTION_NAME);
      set_decl_section_name (vars_decl, OFFLOAD_VAR_TABLE_SECTION_NAME);

      varpool_node::finalize_decl (vars_decl);
      varpool_node::finalize_decl (funcs_decl);
    }
  else
    {
      for (unsigned i = 0; i < num_funcs; i++)
        {
          tree it = (*offload_funcs)[i];
          targetm.record_offload_symbol (it);
        }
      for (unsigned i = 0; i < num_vars; i++)
        {
          tree it = (*offload_vars)[i];
          targetm.record_offload_symbol (it);
        }
    }
}

#include "gt-omp-low.h"