2007-03-01 Paul Brook <paul@codesourcery.com>

[official-gcc.git] / gcc / passes.c

/* Top level of GCC compilers (cc1, cc1plus, etc.)
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   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 2, 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 COPYING.  If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.  */

/* This is the top level of cc1/c++.
   It parses command args, opens files, invokes the various passes
   in the proper order, and counts the time used by each.
   Error messages and low-level interface to malloc also handled here.  */

#include "config.h"
#undef FLOAT /* This is for hpux. They should change hpux.  */
#undef FFS  /* Some systems define this in param.h.  */
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include <signal.h>

#ifdef HAVE_SYS_RESOURCE_H
# include <sys/resource.h>
#endif

#ifdef HAVE_SYS_TIMES_H
# include <sys/times.h>
#endif

#include "line-map.h"
#include "input.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "flags.h"
#include "insn-attr.h"
#include "insn-config.h"
#include "insn-flags.h"
#include "hard-reg-set.h"
#include "recog.h"
#include "output.h"
#include "except.h"
#include "function.h"
#include "toplev.h"
#include "expr.h"
#include "basic-block.h"
#include "intl.h"
#include "ggc.h"
#include "graph.h"
#include "regs.h"
#include "timevar.h"
#include "diagnostic.h"
#include "params.h"
#include "reload.h"
#include "dwarf2asm.h"
#include "integrate.h"
#include "real.h"
#include "debug.h"
#include "target.h"
#include "langhooks.h"
#include "cfglayout.h"
#include "cfgloop.h"
#include "hosthooks.h"
#include "cgraph.h"
#include "opts.h"
#include "coverage.h"
#include "value-prof.h"
#include "tree-inline.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "tree-dump.h"
#include "predict.h"

#if defined (DWARF2_UNWIND_INFO) || defined (DWARF2_DEBUGGING_INFO)
#include "dwarf2out.h"
#endif

#if defined (DBX_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
#include "dbxout.h"
#endif

#ifdef SDB_DEBUGGING_INFO
#include "sdbout.h"
#endif

#ifdef XCOFF_DEBUGGING_INFO
#include "xcoffout.h"           /* Needed for external data
                                   declarations for e.g. AIX 4.x.  */
#endif

/* Global variables used to communicate with passes.  */
int dump_flags;
bool in_gimple_form;


/* This is called from various places for FUNCTION_DECL, VAR_DECL,
   and TYPE_DECL nodes.

   This does nothing for local (non-static) variables, unless the
   variable is a register variable with DECL_ASSEMBLER_NAME set.  In
   that case, or if the variable is not an automatic, it sets up the
   RTL and outputs any assembler code (label definition, storage
   allocation and initialization).

   DECL is the declaration.  TOP_LEVEL is nonzero
   if this declaration is not within a function.  */

void
rest_of_decl_compilation (tree decl,
                          int top_level,
                          int at_end)
{
  /* We deferred calling assemble_alias so that we could collect
     other attributes such as visibility.  Emit the alias now.  */
  {
    tree alias;
    alias = lookup_attribute ("alias", DECL_ATTRIBUTES (decl));
    if (alias)
      {
        alias = TREE_VALUE (TREE_VALUE (alias));
        alias = get_identifier (TREE_STRING_POINTER (alias));
        assemble_alias (decl, alias);
      }
  }

  /* Can't defer this, because it needs to happen before any
     later function definitions are processed.  */
  if (DECL_ASSEMBLER_NAME_SET_P (decl) && DECL_REGISTER (decl))
    make_decl_rtl (decl);

  /* Forward declarations for nested functions are not "external",
     but we need to treat them as if they were.  */
  if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)
      || TREE_CODE (decl) == FUNCTION_DECL)
    {
      timevar_push (TV_VARCONST);

      /* Don't output anything when a tentative file-scope definition
         is seen.  But at end of compilation, do output code for them.

         We do output all variables when unit-at-a-time is active and rely on
         callgraph code to defer them except for forward declarations
         (see gcc.c-torture/compile/920624-1.c) */
      if ((at_end
           || !DECL_DEFER_OUTPUT (decl)
           || DECL_INITIAL (decl))
          && !DECL_EXTERNAL (decl))
        {
          if (TREE_CODE (decl) != FUNCTION_DECL)
            varpool_finalize_decl (decl);
          else
            assemble_variable (decl, top_level, at_end, 0);
        }

#ifdef ASM_FINISH_DECLARE_OBJECT
      if (decl == last_assemble_variable_decl)
        {
          ASM_FINISH_DECLARE_OBJECT (asm_out_file, decl,
                                     top_level, at_end);
        }
#endif

      timevar_pop (TV_VARCONST);
    }
  else if (TREE_CODE (decl) == TYPE_DECL
           /* Like in rest_of_type_compilation, avoid confusing the debug
              information machinery when there are errors.  */
           && !(sorrycount || errorcount))
    {
      timevar_push (TV_SYMOUT);
      debug_hooks->type_decl (decl, !top_level);
      timevar_pop (TV_SYMOUT);
    }

  /* Let cgraph know about the existence of variables.  */
  if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
    varpool_node (decl);
}

/* Called after finishing a record, union or enumeral type.  */

void
rest_of_type_compilation (tree type, int toplev)
{
  /* Avoid confusing the debug information machinery when there are
     errors.  */
  if (errorcount != 0 || sorrycount != 0)
    return;

  timevar_push (TV_SYMOUT);
  debug_hooks->type_decl (TYPE_STUB_DECL (type), !toplev);
  timevar_pop (TV_SYMOUT);
}

\f

void
finish_optimization_passes (void)
{
  enum tree_dump_index i;
  struct dump_file_info *dfi;
  char *name;

  timevar_push (TV_DUMP);
  if (profile_arc_flag || flag_test_coverage || flag_branch_probabilities)
    {
      dump_file = dump_begin (pass_profile.static_pass_number, NULL);
      end_branch_prob ();
      if (dump_file)
        dump_end (pass_profile.static_pass_number, dump_file);
    }

  if (optimize > 0)
    {
      dump_file = dump_begin (pass_combine.static_pass_number, NULL);
      if (dump_file)
        {
          dump_combine_total_stats (dump_file);
          dump_end (pass_combine.static_pass_number, dump_file);
        }
    }

  /* Do whatever is necessary to finish printing the graphs.  */
  if (graph_dump_format != no_graph)
    for (i = TDI_end; (dfi = get_dump_file_info (i)) != NULL; ++i)
      if (dump_initialized_p (i)
          && (dfi->flags & TDF_GRAPH) != 0
          && (name = get_dump_file_name (i)) != NULL)
        {
          finish_graph_dump_file (name);
          free (name);
        }

  timevar_pop (TV_DUMP);
}

static bool
gate_rest_of_compilation (void)
{
  /* Early return if there were errors.  We can run afoul of our
     consistency checks, and there's not really much point in fixing them.  */
  return !(rtl_dump_and_exit || flag_syntax_only || errorcount || sorrycount);
}

struct tree_opt_pass pass_rest_of_compilation =
{
  NULL,                                 /* name */
  gate_rest_of_compilation,             /* gate */
  NULL,                                 /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  TV_REST_OF_COMPILATION,               /* tv_id */
  PROP_rtl,                             /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  TODO_ggc_collect,                     /* todo_flags_finish */
  0                                     /* letter */
};

static bool
gate_postreload (void)
{
  return reload_completed;
}

struct tree_opt_pass pass_postreload =
{
  NULL,                                 /* name */
  gate_postreload,                      /* gate */
  NULL,                                 /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  0,                                    /* tv_id */
  PROP_rtl,                             /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  TODO_ggc_collect,                     /* todo_flags_finish */
  0                                     /* letter */
};



/* The root of the compilation pass tree, once constructed.  */
struct tree_opt_pass *all_passes, *all_ipa_passes, *all_lowering_passes;

/* Iterate over the pass tree allocating dump file numbers.  We want
   to do this depth first, and independent of whether the pass is
   enabled or not.  */

static void
register_one_dump_file (struct tree_opt_pass *pass, bool ipa, int properties)
{
  char *dot_name, *flag_name, *glob_name;
  const char *prefix;
  char num[10];
  int flags;

  /* See below in next_pass_1.  */
  num[0] = '\0';
  if (pass->static_pass_number != -1)
    sprintf (num, "%d", ((int) pass->static_pass_number < 0
                         ? 1 : pass->static_pass_number));

  dot_name = concat (".", pass->name, num, NULL);
  if (ipa)
    prefix = "ipa-", flags = TDF_IPA;
  else if (properties & PROP_trees)
    prefix = "tree-", flags = TDF_TREE;
  else
    prefix = "rtl-", flags = TDF_RTL;

  flag_name = concat (prefix, pass->name, num, NULL);
  glob_name = concat (prefix, pass->name, NULL);
  pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
                                            flags, pass->letter);
}

/* Recursive worker function for register_dump_files.  */

static int 
register_dump_files_1 (struct tree_opt_pass *pass, bool ipa, int properties)
{
  do
    {
      int new_properties = (properties | pass->properties_provided)
                           & ~pass->properties_destroyed;

      if (pass->name)
        register_one_dump_file (pass, ipa, new_properties);

      if (pass->sub)
        new_properties = register_dump_files_1 (pass->sub, false,
                                                new_properties);

      /* If we have a gate, combine the properties that we could have with
         and without the pass being examined.  */
      if (pass->gate)
        properties &= new_properties;
      else
        properties = new_properties;

      pass = pass->next;
    }
  while (pass);

  return properties;
}

/* Register the dump files for the pipeline starting at PASS.  IPA is
   true if the pass is inter-procedural, and PROPERTIES reflects the
   properties that are guaranteed to be available at the beginning of
   the pipeline.  */

static void 
register_dump_files (struct tree_opt_pass *pass, bool ipa, int properties)
{
  pass->properties_required |= properties;
  register_dump_files_1 (pass, ipa, properties);
}

/* Add a pass to the pass list. Duplicate the pass if it's already
   in the list.  */

static struct tree_opt_pass **
next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
{
  /* A nonzero static_pass_number indicates that the
     pass is already in the list.  */
  if (pass->static_pass_number)
    {
      struct tree_opt_pass *new;

      new = xmalloc (sizeof (*new));
      memcpy (new, pass, sizeof (*new));
      new->next = NULL;

      /* Indicate to register_dump_files that this pass has duplicates,
         and so it should rename the dump file.  The first instance will
         be -1, and be number of duplicates = -static_pass_number - 1.
         Subsequent instances will be > 0 and just the duplicate number.  */
      if (pass->name)
        {
          pass->static_pass_number -= 1;
          new->static_pass_number = -pass->static_pass_number;
        }
      
      *list = new;
    }
  else
    {
      pass->static_pass_number = -1;
      *list = pass;
    }  
  
  return &(*list)->next;
          
}

/* Construct the pass tree.  The sequencing of passes is driven by
   the cgraph routines:

   cgraph_finalize_compilation_unit ()
       for each node N in the cgraph
           cgraph_analyze_function (N)
               cgraph_lower_function (N) -> all_lowering_passes

   If we are optimizing, cgraph_optimize is then invoked:

   cgraph_optimize ()
       ipa_passes ()                    -> all_ipa_passes
       cgraph_expand_all_functions ()
           for each node N in the cgraph
               cgraph_expand_function (N)
                   lang_hooks.callgraph.expand_function (DECL (N))
                        tree_rest_of_compilation (DECL (N))  -> all_passes
*/

void
init_optimization_passes (void)
{
  struct tree_opt_pass **p;

#define NEXT_PASS(PASS)  (p = next_pass_1 (p, &PASS))

 /* All passes needed to lower the function into shape optimizers can
    operate on.  These passes are always run first on the function, but
    backend might produce already lowered functions that are not processed
    by these passes.  */
  p = &all_lowering_passes;
  NEXT_PASS (pass_remove_useless_stmts);
  NEXT_PASS (pass_mudflap_1);
  NEXT_PASS (pass_lower_omp);
  NEXT_PASS (pass_lower_cf);
  NEXT_PASS (pass_lower_eh);
  NEXT_PASS (pass_build_cfg);
  NEXT_PASS (pass_lower_complex_O0);
  NEXT_PASS (pass_lower_vector);
  NEXT_PASS (pass_warn_function_return);
  NEXT_PASS (pass_build_cgraph_edges);
  NEXT_PASS (pass_inline_parameters);
  *p = NULL;

  /* Interprocedural optimization passes. 
     All these passes are ignored in -fno-unit-at-a-time
     except for subpases of early_local_pases.  */
  p = &all_ipa_passes;
  NEXT_PASS (pass_ipa_function_and_variable_visibility);
  NEXT_PASS (pass_ipa_early_inline);
    {
      struct tree_opt_pass **p = &pass_ipa_early_inline.sub;
      NEXT_PASS (pass_early_inline);
      NEXT_PASS (pass_inline_parameters);
      NEXT_PASS (pass_rebuild_cgraph_edges);
    }
  NEXT_PASS (pass_early_local_passes);
    {
      struct tree_opt_pass **p = &pass_early_local_passes.sub;
      NEXT_PASS (pass_tree_profile);
      NEXT_PASS (pass_cleanup_cfg);
      NEXT_PASS (pass_init_datastructures);
      NEXT_PASS (pass_expand_omp);
      NEXT_PASS (pass_all_early_optimizations);
        {
          struct tree_opt_pass **p = &pass_all_early_optimizations.sub;
          NEXT_PASS (pass_referenced_vars);
          NEXT_PASS (pass_reset_cc_flags);
          NEXT_PASS (pass_build_ssa);
          NEXT_PASS (pass_early_warn_uninitialized);
          NEXT_PASS (pass_rebuild_cgraph_edges);
          NEXT_PASS (pass_early_inline);
          NEXT_PASS (pass_cleanup_cfg);
          NEXT_PASS (pass_rename_ssa_copies);
          NEXT_PASS (pass_ccp);
          NEXT_PASS (pass_forwprop);
          NEXT_PASS (pass_sra_early);
          NEXT_PASS (pass_copy_prop);
          NEXT_PASS (pass_merge_phi);
          NEXT_PASS (pass_dce);
          NEXT_PASS (pass_tail_recursion);
          NEXT_PASS (pass_profile);
          NEXT_PASS (pass_release_ssa_names);
        }
      NEXT_PASS (pass_rebuild_cgraph_edges);
      NEXT_PASS (pass_inline_parameters);
    }
  NEXT_PASS (pass_ipa_increase_alignment);
  NEXT_PASS (pass_ipa_cp);
  NEXT_PASS (pass_ipa_inline);
  NEXT_PASS (pass_ipa_reference);
  NEXT_PASS (pass_ipa_pure_const); 
  NEXT_PASS (pass_ipa_type_escape);
  NEXT_PASS (pass_ipa_pta);
  *p = NULL;

  /* These passes are run after IPA passes on every function that is being
     output to the assembler file.  */
  p = &all_passes;
  NEXT_PASS (pass_apply_inline);
  NEXT_PASS (pass_all_optimizations);
    {
      struct tree_opt_pass **p = &pass_all_optimizations.sub;
      NEXT_PASS (pass_create_structure_vars);
      NEXT_PASS (pass_may_alias);
      NEXT_PASS (pass_return_slot);
      NEXT_PASS (pass_rename_ssa_copies);

      /* Initial scalar cleanups.  */
      NEXT_PASS (pass_ccp);
      NEXT_PASS (pass_fre);
      NEXT_PASS (pass_dce);
      NEXT_PASS (pass_forwprop);
      NEXT_PASS (pass_copy_prop);
      NEXT_PASS (pass_merge_phi);
      NEXT_PASS (pass_vrp);
      NEXT_PASS (pass_dce);
      NEXT_PASS (pass_dominator);

      /* The only const/copy propagation opportunities left after
         DOM should be due to degenerate PHI nodes.  So rather than
         run the full propagators, run a specialized pass which
         only examines PHIs to discover const/copy propagation
         opportunities.  */
      NEXT_PASS (pass_phi_only_cprop);

      NEXT_PASS (pass_phiopt);
      NEXT_PASS (pass_may_alias);
      NEXT_PASS (pass_tail_recursion);
      NEXT_PASS (pass_ch);
      NEXT_PASS (pass_stdarg);
      NEXT_PASS (pass_lower_complex);
      NEXT_PASS (pass_sra);
      /* FIXME: SRA may generate arbitrary gimple code, exposing new
         aliased and call-clobbered variables.  As mentioned below,
         pass_may_alias should be a TODO item.  */
      NEXT_PASS (pass_may_alias);
      NEXT_PASS (pass_rename_ssa_copies);
      NEXT_PASS (pass_dominator);

      /* The only const/copy propagation opportunities left after
         DOM should be due to degenerate PHI nodes.  So rather than
         run the full propagators, run a specialized pass which
         only examines PHIs to discover const/copy propagation
         opportunities.  */
      NEXT_PASS (pass_phi_only_cprop);

      NEXT_PASS (pass_reassoc);
      NEXT_PASS (pass_dce);
      NEXT_PASS (pass_dse);
      NEXT_PASS (pass_may_alias);
      NEXT_PASS (pass_forwprop);
      NEXT_PASS (pass_phiopt);
      NEXT_PASS (pass_object_sizes);
      NEXT_PASS (pass_store_ccp);
      NEXT_PASS (pass_store_copy_prop);
      NEXT_PASS (pass_fold_builtins);
      NEXT_PASS (pass_cse_sincos);
      /* FIXME: May alias should a TODO but for 4.0.0,
         we add may_alias right after fold builtins
         which can create arbitrary GIMPLE.  */
      NEXT_PASS (pass_may_alias);
      NEXT_PASS (pass_split_crit_edges);
      NEXT_PASS (pass_pre);
      NEXT_PASS (pass_may_alias);
      NEXT_PASS (pass_sink_code);
      NEXT_PASS (pass_tree_loop);
        {
          struct tree_opt_pass **p = &pass_tree_loop.sub;
          NEXT_PASS (pass_tree_loop_init);
          NEXT_PASS (pass_copy_prop);
          NEXT_PASS (pass_lim);
          NEXT_PASS (pass_tree_unswitch);
          NEXT_PASS (pass_scev_cprop);
          NEXT_PASS (pass_empty_loop);
          NEXT_PASS (pass_record_bounds);
          NEXT_PASS (pass_linear_transform);
          NEXT_PASS (pass_iv_canon);
          NEXT_PASS (pass_if_conversion);
          NEXT_PASS (pass_vectorize);
            {
              struct tree_opt_pass **p = &pass_vectorize.sub;
              NEXT_PASS (pass_lower_vector_ssa);
              NEXT_PASS (pass_dce_loop);
            }
          /* NEXT_PASS (pass_may_alias) cannot be done again because the
             vectorizer creates alias relations that are not supported by
             pass_may_alias.  */
          NEXT_PASS (pass_complete_unroll);
          NEXT_PASS (pass_loop_prefetch);
          NEXT_PASS (pass_iv_optimize);
          NEXT_PASS (pass_tree_loop_done);
        }
      NEXT_PASS (pass_cse_reciprocals);
      NEXT_PASS (pass_reassoc);
      NEXT_PASS (pass_vrp);
      NEXT_PASS (pass_dominator);

      /* The only const/copy propagation opportunities left after
         DOM should be due to degenerate PHI nodes.  So rather than
         run the full propagators, run a specialized pass which
         only examines PHIs to discover const/copy propagation
         opportunities.  */
      NEXT_PASS (pass_phi_only_cprop);

      NEXT_PASS (pass_cd_dce);

      /* FIXME: If DCE is not run before checking for uninitialized uses,
         we may get false warnings (e.g., testsuite/gcc.dg/uninit-5.c).
         However, this also causes us to misdiagnose cases that should be
         real warnings (e.g., testsuite/gcc.dg/pr18501.c).
         
         To fix the false positives in uninit-5.c, we would have to
         account for the predicates protecting the set and the use of each
         variable.  Using a representation like Gated Single Assignment
         may help.  */
      NEXT_PASS (pass_late_warn_uninitialized);
      NEXT_PASS (pass_dse);
      NEXT_PASS (pass_forwprop);
      NEXT_PASS (pass_phiopt);
      NEXT_PASS (pass_tail_calls);
      NEXT_PASS (pass_rename_ssa_copies);
      NEXT_PASS (pass_uncprop);
      NEXT_PASS (pass_del_ssa);
      NEXT_PASS (pass_nrv);
      NEXT_PASS (pass_mark_used_blocks);
      NEXT_PASS (pass_cleanup_cfg_post_optimizing);
    }
  NEXT_PASS (pass_warn_function_noreturn);
  NEXT_PASS (pass_free_datastructures);
  NEXT_PASS (pass_mudflap_2);
  NEXT_PASS (pass_free_cfg_annotations);
  NEXT_PASS (pass_expand);
  NEXT_PASS (pass_rest_of_compilation);
    {
      struct tree_opt_pass **p = &pass_rest_of_compilation.sub;
      NEXT_PASS (pass_init_function);
      NEXT_PASS (pass_jump);
      NEXT_PASS (pass_insn_locators_initialize);
      NEXT_PASS (pass_rtl_eh);
      NEXT_PASS (pass_initial_value_sets);
      NEXT_PASS (pass_unshare_all_rtl);
      NEXT_PASS (pass_instantiate_virtual_regs);
      NEXT_PASS (pass_jump2);
      NEXT_PASS (pass_lower_subreg);
      NEXT_PASS (pass_cse);
      NEXT_PASS (pass_rtl_fwprop);
      NEXT_PASS (pass_gcse);
      NEXT_PASS (pass_jump_bypass);
      NEXT_PASS (pass_rtl_ifcvt);
      NEXT_PASS (pass_tracer);
      /* Perform loop optimizations.  It might be better to do them a bit
         sooner, but we want the profile feedback to work more
         efficiently.  */
      NEXT_PASS (pass_loop2);
        {
          struct tree_opt_pass **p = &pass_loop2.sub;
          NEXT_PASS (pass_rtl_loop_init);
          NEXT_PASS (pass_rtl_move_loop_invariants);
          NEXT_PASS (pass_rtl_unswitch);
          NEXT_PASS (pass_rtl_unroll_and_peel_loops);
          NEXT_PASS (pass_rtl_doloop);
          NEXT_PASS (pass_rtl_loop_done);
          *p = NULL;
        }
      NEXT_PASS (pass_web);
      NEXT_PASS (pass_cse2);
      NEXT_PASS (pass_rtl_fwprop_addr);
      NEXT_PASS (pass_life);
      NEXT_PASS (pass_combine);
      NEXT_PASS (pass_if_after_combine);
      NEXT_PASS (pass_partition_blocks);
      NEXT_PASS (pass_regmove);
      NEXT_PASS (pass_split_all_insns);
      NEXT_PASS (pass_lower_subreg2);
      NEXT_PASS (pass_mode_switching);
      NEXT_PASS (pass_see);
      NEXT_PASS (pass_recompute_reg_usage);
      NEXT_PASS (pass_sms);
      NEXT_PASS (pass_sched);
      NEXT_PASS (pass_local_alloc);
      NEXT_PASS (pass_global_alloc);
      NEXT_PASS (pass_postreload);
        {
          struct tree_opt_pass **p = &pass_postreload.sub;
          NEXT_PASS (pass_postreload_cse);
          NEXT_PASS (pass_gcse2);
          NEXT_PASS (pass_flow2);
          NEXT_PASS (pass_rtl_seqabstr);
          NEXT_PASS (pass_stack_adjustments);
          NEXT_PASS (pass_peephole2);
          NEXT_PASS (pass_if_after_reload);
          NEXT_PASS (pass_regrename);
          NEXT_PASS (pass_reorder_blocks);
          NEXT_PASS (pass_branch_target_load_optimize);
          NEXT_PASS (pass_leaf_regs);
          NEXT_PASS (pass_sched2);
          NEXT_PASS (pass_split_before_regstack);
          NEXT_PASS (pass_stack_regs);
          NEXT_PASS (pass_compute_alignments);
          NEXT_PASS (pass_duplicate_computed_gotos);
          NEXT_PASS (pass_variable_tracking);
          NEXT_PASS (pass_free_cfg);
          NEXT_PASS (pass_machine_reorg);
          NEXT_PASS (pass_cleanup_barriers);
          NEXT_PASS (pass_delay_slots);
          NEXT_PASS (pass_split_for_shorten_branches);
          NEXT_PASS (pass_convert_to_eh_region_ranges);
          NEXT_PASS (pass_shorten_branches);
          NEXT_PASS (pass_set_nothrow_function_flags);
          NEXT_PASS (pass_final);
        }
    }
  NEXT_PASS (pass_clean_state);
  *p = NULL;

#undef NEXT_PASS

  /* Register the passes with the tree dump code.  */
  register_dump_files (all_lowering_passes, false, PROP_gimple_any);
  all_lowering_passes->todo_flags_start |= TODO_set_props;
  register_dump_files (all_ipa_passes, true,
                       PROP_gimple_any | PROP_gimple_lcf | PROP_gimple_leh
                       | PROP_cfg);
  register_dump_files (all_passes, false,
                       PROP_gimple_any | PROP_gimple_lcf | PROP_gimple_leh
                       | PROP_cfg);
}

/* If we are in IPA mode (i.e., current_function_decl is NULL), call
   function CALLBACK for every function in the call graph.  Otherwise,
   call CALLBACK on the current function.  */ 

static void
do_per_function (void (*callback) (void *data), void *data)
{
  if (current_function_decl)
    callback (data);
  else
    {
      struct cgraph_node *node;
      for (node = cgraph_nodes; node; node = node->next)
        if (node->analyzed)
          {
            push_cfun (DECL_STRUCT_FUNCTION (node->decl));
            current_function_decl = node->decl;
            callback (data);
            free_dominance_info (CDI_DOMINATORS);
            free_dominance_info (CDI_POST_DOMINATORS);
            current_function_decl = NULL;
            pop_cfun ();
            ggc_collect ();
          }
    }
}

/* Because inlining might remove no-longer reachable nodes, we need to
   keep the array visible to garbage collector to avoid reading collected
   out nodes.  */
static int nnodes;
static GTY ((length ("nnodes"))) struct cgraph_node **order;

/* If we are in IPA mode (i.e., current_function_decl is NULL), call
   function CALLBACK for every function in the call graph.  Otherwise,
   call CALLBACK on the current function.  */ 

static void
do_per_function_toporder (void (*callback) (void *data), void *data)
{
  int i;

  if (current_function_decl)
    callback (data);
  else
    {
      gcc_assert (!order);
      order = ggc_alloc (sizeof (*order) * cgraph_n_nodes);
      nnodes = cgraph_postorder (order);
      for (i = nnodes - 1; i >= 0; i--)
        {
          struct cgraph_node *node = order[i];

          /* Allow possibly removed nodes to be garbage collected.  */
          order[i] = NULL;
          if (node->analyzed && (node->needed || node->reachable))
            {
              push_cfun (DECL_STRUCT_FUNCTION (node->decl));
              current_function_decl = node->decl;
              callback (data);
              free_dominance_info (CDI_DOMINATORS);
              free_dominance_info (CDI_POST_DOMINATORS);
              current_function_decl = NULL;
              pop_cfun ();
              ggc_collect ();
            }
        }
    }
  ggc_free (order);
  order = NULL;
  nnodes = 0;
}

/* Perform all TODO actions that ought to be done on each function.  */

static void
execute_function_todo (void *data)
{
  unsigned int flags = (size_t)data;
  if (cfun->curr_properties & PROP_ssa)
    flags |= TODO_verify_ssa;
  flags &= ~cfun->last_verified;
  if (!flags)
    return;
  
  /* Always cleanup the CFG before trying to update SSA.  */
  if (flags & TODO_cleanup_cfg)
    {
      bool cleanup;

      if (current_loops)
        cleanup = cleanup_tree_cfg_loop ();
      else
        cleanup = cleanup_tree_cfg ();

      if (cleanup && (cfun->curr_properties & PROP_ssa))
        flags |= TODO_remove_unused_locals;
        
      /* When cleanup_tree_cfg merges consecutive blocks, it may
         perform some simplistic propagation when removing single
         valued PHI nodes.  This propagation may, in turn, cause the
         SSA form to become out-of-date (see PR 22037).  So, even
         if the parent pass had not scheduled an SSA update, we may
         still need to do one.  */
      if (!(flags & TODO_update_ssa_any) && need_ssa_update_p ())
        flags |= TODO_update_ssa;
    }

  if (flags & TODO_update_ssa_any)
    {
      unsigned update_flags = flags & TODO_update_ssa_any;
      update_ssa (update_flags);
      cfun->last_verified &= ~TODO_verify_ssa;
    }

  if (flags & TODO_remove_unused_locals)
    remove_unused_locals ();

  if ((flags & TODO_dump_func)
      && dump_file && current_function_decl)
    {
      if (cfun->curr_properties & PROP_trees)
        dump_function_to_file (current_function_decl,
                               dump_file, dump_flags);
      else
        {
          if (dump_flags & TDF_SLIM)
            print_rtl_slim_with_bb (dump_file, get_insns (), dump_flags);
          else if ((cfun->curr_properties & PROP_cfg)
                   && (dump_flags & TDF_BLOCKS))
            print_rtl_with_bb (dump_file, get_insns ());
          else
            print_rtl (dump_file, get_insns ());

          if (cfun->curr_properties & PROP_cfg
              && graph_dump_format != no_graph
              && (dump_flags & TDF_GRAPH))
            print_rtl_graph_with_bb (dump_file_name, get_insns ());
        }

      /* Flush the file.  If verification fails, we won't be able to
         close the file before aborting.  */
      fflush (dump_file);
    }

  if (flags & TODO_rebuild_frequencies)
    {
      if (profile_status == PROFILE_GUESSED)
        {
          loop_optimizer_init (0);
          add_noreturn_fake_exit_edges ();
          mark_irreducible_loops ();
          connect_infinite_loops_to_exit ();
          estimate_bb_frequencies ();
          remove_fake_exit_edges ();
          loop_optimizer_finalize ();
        }
      else if (profile_status == PROFILE_READ)
        counts_to_freqs ();
      else
        gcc_unreachable ();
    }

#if defined ENABLE_CHECKING
  if (flags & TODO_verify_ssa)
    verify_ssa (true);
  if (flags & TODO_verify_flow)
    verify_flow_info ();
  if (flags & TODO_verify_stmts)
    verify_stmts ();
  if (flags & TODO_verify_loops)
    verify_loop_closed_ssa ();
#endif

  cfun->last_verified = flags & TODO_verify_all;
}

/* Perform all TODO actions.  */
static void
execute_todo (unsigned int flags)
{
#if defined ENABLE_CHECKING
  if (need_ssa_update_p ())
    gcc_assert (flags & TODO_update_ssa_any);
#endif

  do_per_function (execute_function_todo, (void *)(size_t) flags);

  /* Always remove functions just as before inlining: IPA passes might be
     interested to see bodies of extern inline functions that are not inlined
     to analyze side effects.  The full removal is done just at the end
     of IPA pass queue.  */
  if (flags & TODO_remove_functions)
    cgraph_remove_unreachable_nodes (true, dump_file);

  if ((flags & TODO_dump_cgraph)
      && dump_file && !current_function_decl)
    {
      dump_cgraph (dump_file);
      /* Flush the file.  If verification fails, we won't be able to
         close the file before aborting.  */
      fflush (dump_file);
    }

  if (flags & TODO_ggc_collect)
    {
      ggc_collect ();
    }
}

/* Verify invariants that should hold between passes.  This is a place
   to put simple sanity checks.  */

static void
verify_interpass_invariants (void)
{
#ifdef ENABLE_CHECKING
  gcc_assert (!fold_deferring_overflow_warnings_p ());
#endif
}

/* Clear the last verified flag.  */

static void
clear_last_verified (void *data ATTRIBUTE_UNUSED)
{
  cfun->last_verified = 0;
}

/* Helper function. Verify that the properties has been turn into the
   properties expected by the pass.  */

#ifdef ENABLE_CHECKING
static void
verify_curr_properties (void *data)
{
  unsigned int props = (size_t)data;
  gcc_assert ((cfun->curr_properties & props) == props);
}
#endif

/* After executing the pass, apply expected changes to the function
   properties. */
static void
update_properties_after_pass (void *data)
{
  struct tree_opt_pass *pass = data;
  cfun->curr_properties = (cfun->curr_properties | pass->properties_provided)
                           & ~pass->properties_destroyed;
}

static bool
execute_one_pass (struct tree_opt_pass *pass)
{
  bool initializing_dump;
  unsigned int todo_after = 0;

  /* See if we're supposed to run this pass.  */
  if (pass->gate && !pass->gate ())
    return false;

  if (!quiet_flag && !cfun)
    fprintf (stderr, " <%s>", pass->name ? pass->name : "");

  if (pass->todo_flags_start & TODO_set_props)
    cfun->curr_properties = pass->properties_required;

  /* Note that the folders should only create gimple expressions.
     This is a hack until the new folder is ready.  */
  in_gimple_form = (cfun && (cfun->curr_properties & PROP_trees)) != 0;

  /* Run pre-pass verification.  */
  execute_todo (pass->todo_flags_start);

#ifdef ENABLE_CHECKING
  do_per_function (verify_curr_properties,
                   (void *)(size_t)pass->properties_required);
#endif

  /* If a dump file name is present, open it if enabled.  */
  if (pass->static_pass_number != -1)
    {
      initializing_dump = !dump_initialized_p (pass->static_pass_number);
      dump_file_name = get_dump_file_name (pass->static_pass_number);
      dump_file = dump_begin (pass->static_pass_number, &dump_flags);
      if (dump_file && current_function_decl)
        {
          const char *dname, *aname;
          dname = lang_hooks.decl_printable_name (current_function_decl, 2);
          aname = (IDENTIFIER_POINTER
                   (DECL_ASSEMBLER_NAME (current_function_decl)));
          fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname,
             cfun->function_frequency == FUNCTION_FREQUENCY_HOT
             ? " (hot)"
             : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
             ? " (unlikely executed)"
             : "");
        }
    }
  else
    initializing_dump = false;

  /* If a timevar is present, start it.  */
  if (pass->tv_id)
    timevar_push (pass->tv_id);

  /* Do it!  */
  if (pass->execute)
    {
      todo_after = pass->execute ();
      do_per_function (clear_last_verified, NULL);
    }

  /* Stop timevar.  */
  if (pass->tv_id)
    timevar_pop (pass->tv_id);

  do_per_function (update_properties_after_pass, pass);

  if (initializing_dump
      && dump_file
      && graph_dump_format != no_graph
      && (cfun->curr_properties & (PROP_cfg | PROP_rtl))
          == (PROP_cfg | PROP_rtl))
    {
      get_dump_file_info (pass->static_pass_number)->flags |= TDF_GRAPH;
      dump_flags |= TDF_GRAPH;
      clean_graph_dump_file (dump_file_name);
    }

  /* Run post-pass cleanup and verification.  */
  execute_todo (todo_after | pass->todo_flags_finish);
  verify_interpass_invariants ();

  if (!current_function_decl)
    cgraph_process_new_functions ();

  /* Flush and close dump file.  */
  if (dump_file_name)
    {
      free ((char *) dump_file_name);
      dump_file_name = NULL;
    }

  if (dump_file)
    {
      dump_end (pass->static_pass_number, dump_file);
      dump_file = NULL;
    }

  /* Reset in_gimple_form to not break non-unit-at-a-time mode.  */
  in_gimple_form = false;

  return true;
}

void
execute_pass_list (struct tree_opt_pass *pass)
{
  do
    {
      if (execute_one_pass (pass) && pass->sub)
        execute_pass_list (pass->sub);
      pass = pass->next;
    }
  while (pass);
}

/* Same as execute_pass_list but assume that subpasses of IPA passes
   are local passes.  */
void
execute_ipa_pass_list (struct tree_opt_pass *pass)
{
  do
    {
      gcc_assert (!current_function_decl);
      gcc_assert (!cfun);
      if (execute_one_pass (pass) && pass->sub)
        do_per_function_toporder ((void (*)(void *))execute_pass_list,
                                  pass->sub);
      if (!current_function_decl)
        cgraph_process_new_functions ();
      pass = pass->next;
    }
  while (pass);
}
#include "gt-passes.h"