2008-05-08 Vladimir Makarov <vmakarov@redhat.com>

[official-gcc.git] / gcc / ira-emit.c

/* Integrated Register Allocator.  Changing code and generating moves.
   Copyright (C) 2006, 2007, 2008
   Free Software Foundation, Inc.
   Contributed by Vladimir Makarov <vmakarov@redhat.com>.

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 "tm.h"
#include "regs.h"
#include "rtl.h"
#include "tm_p.h"
#include "target.h"
#include "flags.h"
#include "obstack.h"
#include "bitmap.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "expr.h"
#include "recog.h"
#include "params.h"
#include "timevar.h"
#include "tree-pass.h"
#include "output.h"
#include "reload.h"
#include "errors.h"
#include "df.h"
#include "ira-int.h"


/* The structure represents an allocno move.  The both allocnos have
   the same origional regno but different allocation.  */
struct move
{
  /* The allocnos involved in the move.  */
  allocno_t from, to;
  /* The next move in the move sequence.  */
  struct move *next;
  /* Used for finding dependencies.  */
  int visited_p;
  /* The size of the following array. */
  int deps_num;
  /* Moves on which given move depends on.  Dependency can be cyclic.
     It means we need a temporary to generates the moves.  Sequence
     A1->A2, B1->B2 where A1 and B2 are assigned to reg R1 and A2 and
     B1 are assigned to reg R2 is an example of the cyclic
     dependencies.  */
  struct move **deps;
  /* First insn generated for the move.  */
  rtx insn;
};

/* Array of moves (indexed by BB index) which should be put at the
   start/end of the corresponding basic blocks.  */
static struct move **at_bb_start, **at_bb_end;

/* Max regno before renaming some pseudo-registers.  For example, the
   same pseudo-register can be renamed in a loop if its allocation is
   different outside the loop.  */
static int max_regno_before_changing;

static struct move *create_move (allocno_t, allocno_t);
static void free_move (struct move *);
static void free_move_list (struct move *);
static int eq_move_lists_p (struct move *, struct move *);
static int change_regs (rtx *);
static void add_to_edge_list (edge, struct move *, int);
static rtx create_new_reg (rtx);
static int subloop_tree_node_p (loop_tree_node_t, loop_tree_node_t);
static void set_allocno_reg (allocno_t, rtx);
static int not_modified_p (allocno_t, allocno_t);
static void generate_edge_moves (edge);
static void change_loop (loop_tree_node_t);
static void set_allocno_somewhere_renamed_p (void);
static int eq_edge_move_lists_p (VEC(edge,gc) *);
static void unify_moves (basic_block, int);
static void traverse_moves (struct move *);
static struct move *modify_move_list (struct move *);
static rtx emit_move_list (struct move *, int);
static void emit_moves (void);
static void update_costs (allocno_t, int, int);
static void add_range_and_copies_from_move_list (struct move *,
                                                 loop_tree_node_t,
                                                 bitmap, int);
static void add_ranges_and_copies (void);

/* The function returns new move of allocnos TO and FROM.  */
static struct move *
create_move (allocno_t to, allocno_t from)
{
  struct move *move;

  move = ira_allocate (sizeof (struct move));
  move->deps = NULL;
  move->deps_num = 0;
  move->to = to;
  move->from = from;
  move->next = NULL;
  move->insn = NULL_RTX;
  move->visited_p = FALSE;
  return move;
}

/* The function frees memory for MOVE and its dependencies.  */
static void
free_move (struct move *move)
{
  if (move->deps != NULL)
    ira_free (move->deps);
  ira_free (move);
}

/* The function frees memory for list of the moves given by its
   HEAD.  */
static void
free_move_list (struct move *head)
{
  struct move *next;
  
  for (; head != NULL; head = next)
    {
      next = head->next;
      free_move (head);
    }
}

/* The function returns nonzero if the the move list LIST1 and LIST2
   are equal (two moves are equal if they involve the same
   allocnos).  */
static int
eq_move_lists_p (struct move *list1, struct move *list2)
{
  for (; list1 != NULL && list2 != NULL;
       list1 = list1->next, list2 = list2->next)
    if (list1->from != list2->from || list1->to != list2->to)
      return FALSE;
  return list1 == list2;
}

/* This recursive function changes pseudo-registers in *LOC if it is
   necessary.  The function returns TRUE if a change was done.  */
static int
change_regs (rtx *loc)
{
  int i, regno, result = FALSE;
  const char *fmt;
  enum rtx_code code;

  if (*loc == NULL_RTX)
    return FALSE;
  code = GET_CODE (*loc);
  if (code == REG)
    {
      regno = REGNO (*loc);
      if (regno < FIRST_PSEUDO_REGISTER)
        return FALSE;
      if (regno >= max_regno_before_changing)
        /* It is a shared register which was changed already.  */
        return FALSE;
      if (ira_curr_regno_allocno_map[regno] == NULL)
        return FALSE;
      *loc = ALLOCNO_REG (ira_curr_regno_allocno_map[regno]);
      return TRUE;
    }

  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'e')
        result = change_regs (&XEXP (*loc, i)) || result;
      else if (fmt[i] == 'E')
        {
          int j;

          for (j = XVECLEN (*loc, i) - 1; j >= 0; j--)
            result = change_regs (&XVECEXP (*loc, i, j)) || result;
        }
    }
  return result;
}

/* The function attaches MOVE to the edge E.  The move is attached to
   the head of the list if HEAD_P is nonzero.  */
static void
add_to_edge_list (edge e, struct move *move, int head_p)
{
  struct move *last;

  if (head_p || e->aux == NULL)
    {
      move->next = e->aux;
      e->aux = move;
    }
  else
    {
      for (last = e->aux; last->next != NULL; last = last->next)
        ;
      last->next = move;
      move->next = NULL;
    }
}

/* The function creates and returns new pseudo-register with the same
   attributes as ORIGINAL_REG.  */
static rtx
create_new_reg (rtx original_reg)
{
  rtx new_reg;

  new_reg = gen_reg_rtx (GET_MODE (original_reg));
  ORIGINAL_REGNO (new_reg) = ORIGINAL_REGNO (original_reg);
  REG_USERVAR_P (new_reg) = REG_USERVAR_P (original_reg);
  REG_POINTER (new_reg) = REG_POINTER (original_reg);
  REG_ATTRS (new_reg) = REG_ATTRS (original_reg);
  if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
    fprintf (ira_dump_file, "      Creating newreg=%i from oldreg=%i\n",
             REGNO (new_reg), REGNO (original_reg));
  return new_reg;
}

/* The function returns TRUE if loop given by SUBNODE inside the
   loop given by NODE.  */
static int
subloop_tree_node_p (loop_tree_node_t subnode, loop_tree_node_t node)
{
  for (; subnode != NULL; subnode = subnode->father)
    if (subnode == node)
      return TRUE;
  return FALSE;
}

/* The function sets up member `reg' to REG for allocnos which has the
   same regno as ALLOCNO and which are inside the loop corresponding to
   ALLOCNO. */
static void
set_allocno_reg (allocno_t allocno, rtx reg)
{
  int regno;
  allocno_t a;
  loop_tree_node_t node;

  node = ALLOCNO_LOOP_TREE_NODE (allocno);
  for (a = regno_allocno_map[ALLOCNO_REGNO (allocno)];
       a != NULL;
       a = ALLOCNO_NEXT_REGNO_ALLOCNO (a))
    if (subloop_tree_node_p (ALLOCNO_LOOP_TREE_NODE (a), node))
      ALLOCNO_REG (a) = reg;
  for (a = ALLOCNO_CAP (allocno); a != NULL; a = ALLOCNO_CAP (a))
    ALLOCNO_REG (a) = reg;
  regno = ALLOCNO_REGNO (allocno);
  for (a = allocno;;)
    {
      if (a == NULL || (a = ALLOCNO_CAP (a)) == NULL)
        {
          node = node->father;
          if (node == NULL)
            break;
          a = node->regno_allocno_map[regno];
        }
      if (a == NULL)
        continue;
      if (ALLOCNO_CHILD_RENAMED_P (a))
        break;
      ALLOCNO_CHILD_RENAMED_P (a) = TRUE;
    }
}

/* The following function returns TRUE if move of SRC_ALLOCNO to
   DEST_ALLOCNO does not change value of the destination.  One possible
   reason for this is the situation when SRC_ALLOCNO is not modified
   in the corresponding loop.  */
static int
not_modified_p (allocno_t src_allocno, allocno_t dest_allocno)
{
  int regno, orig_regno;
  allocno_t a;
  loop_tree_node_t node;

  orig_regno = ALLOCNO_REGNO (src_allocno);
  regno = REGNO (ALLOCNO_REG (dest_allocno));
  for (node = ALLOCNO_LOOP_TREE_NODE (src_allocno);
       node != NULL;
       node = node->father)
    if ((a = node->regno_allocno_map[orig_regno]) == NULL)
      break;
    else if (REGNO (ALLOCNO_REG (a)) == (unsigned) regno)
      return TRUE;
    else if (bitmap_bit_p (node->modified_regnos, orig_regno))
      return FALSE;
  return node != NULL;
}

/* The function generates and attaches moves to the edge E.  It looks
   at the final regnos of allocnos living on the edge with the same
   original regno to figure out when moves should be generated.  */
static void
generate_edge_moves (edge e)
{
  loop_tree_node_t src_loop_node, dest_loop_node;
  unsigned int regno;
  bitmap_iterator bi;
  allocno_t src_allocno, dest_allocno, *src_map, *dest_map;
  struct move *move;

  src_loop_node = IRA_BB_NODE (e->src)->father;
  dest_loop_node = IRA_BB_NODE (e->dest)->father;
  e->aux = NULL;
  if (src_loop_node == dest_loop_node)
    return;
  src_map = src_loop_node->regno_allocno_map;
  dest_map = dest_loop_node->regno_allocno_map;
  EXECUTE_IF_SET_IN_REG_SET (DF_LR_IN (e->dest),
                             FIRST_PSEUDO_REGISTER, regno, bi)
    if (bitmap_bit_p (DF_LR_OUT (e->src), regno))
      {
        src_allocno = src_map[regno];
        dest_allocno = dest_map[regno];
        if (REGNO (ALLOCNO_REG (src_allocno))
            == REGNO (ALLOCNO_REG (dest_allocno)))
          continue;
        /* Actually it is not a optimization we need this code because
           the memory (remember about equivalent memory) might be ROM
           (or placed in read only section).  */
        if (ALLOCNO_HARD_REGNO (dest_allocno) < 0
            && ALLOCNO_HARD_REGNO (src_allocno) >= 0
            && not_modified_p (src_allocno, dest_allocno))
          {
            ALLOCNO_MEM_OPTIMIZED_DEST (src_allocno) = dest_allocno;
            ALLOCNO_MEM_OPTIMIZED_DEST_P (dest_allocno) = TRUE;
            if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
              fprintf (ira_dump_file, "      Remove r%d:a%d->a%d(mem)\n",
                       regno, ALLOCNO_NUM (src_allocno),
                       ALLOCNO_NUM (dest_allocno));
            continue;
          }
        move = create_move (dest_allocno, src_allocno);
        add_to_edge_list (e, move, TRUE);
    }
}

/* Bitmap of allocnos local for the current loop.  */
static bitmap local_allocno_bitmap;

/* This bitmap is used to find that we need to generate and to use a
   new pseudo-register when processing allocnos with the same original
   regno.  */
static bitmap used_regno_bitmap;

/* This bitmap contains regnos of allocnos which were renamed locally
   because the allocnos correspond to disjoint live ranges in loops
   with a common parent.  */
static bitmap renamed_regno_bitmap;

/* The following function changes (if necessary) pseudo-registers
   inside loop given by loop tree node NODE.  */
static void
change_loop (loop_tree_node_t node)
{
  bitmap_iterator bi;
  unsigned int i;
  int regno, used_p;
  allocno_t allocno, father_allocno, *map;
  rtx insn, original_reg;
  enum reg_class cover_class;
  loop_tree_node_t father;

  if (node != ira_loop_tree_root)
    {
      
      if (node->bb != NULL)
        {
          FOR_BB_INSNS (node->bb, insn)
            if (INSN_P (insn) && change_regs (&insn))
              {
                df_insn_rescan (insn);
                df_notes_rescan (insn);
              }
          return;
        }
      
      if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
        fprintf (ira_dump_file,
                 "      Changing RTL for loop %d (header bb%d)\n",
                 node->loop->num, node->loop->header->index);
      
      father = ira_curr_loop_tree_node->father;
      map = father->regno_allocno_map;
      EXECUTE_IF_SET_IN_REG_SET (ira_curr_loop_tree_node->border_allocnos,
                                 0, i, bi)
        {
          allocno = allocnos[i];
          regno = ALLOCNO_REGNO (allocno);
          cover_class = ALLOCNO_COVER_CLASS (allocno);
          father_allocno = map[regno];
          ira_assert (regno < reg_equiv_len);
          /* We generate the same hard register move because the
             reload pass can put an allocno into memory in this case
             we will have live range splitting.  If it does not happen
             such the same hard register moves will be removed.  The
             worst case when the both allocnos are put into memory by
             the reload is very rare.  */
          if (father_allocno != NULL
              && (ALLOCNO_HARD_REGNO (allocno)
                  == ALLOCNO_HARD_REGNO (father_allocno))
              && (ALLOCNO_HARD_REGNO (allocno) < 0
                  || (father->reg_pressure[cover_class] + 1
                      <= available_class_regs[cover_class])
                  || TEST_HARD_REG_BIT (prohibited_mode_move_regs
                                        [ALLOCNO_MODE (allocno)],
                                        ALLOCNO_HARD_REGNO (allocno))
                  /* don't create copies because reload can spill an
                     allocno set by copy although the allocno will not
                     get memory slot.  */
                  || reg_equiv_invariant_p[regno]
                  || reg_equiv_const[regno] != NULL_RTX))
            continue;
          original_reg = ALLOCNO_REG (allocno);
          if (father_allocno == NULL
              || REGNO (ALLOCNO_REG (father_allocno)) == REGNO (original_reg))
            {
              if (internal_flag_ira_verbose > 3 && ira_dump_file)
                fprintf (ira_dump_file, "  %i vs father %i:",
                         ALLOCNO_HARD_REGNO (allocno),
                         ALLOCNO_HARD_REGNO (father_allocno));
              set_allocno_reg (allocno, create_new_reg (original_reg));
            }
        }
    }
  /* Rename locals: Local allocnos with same regno in different loops
     might get the different hard register.  So we need to change
     ALLOCNO_REG.  */
  bitmap_and_compl (local_allocno_bitmap,
                    ira_curr_loop_tree_node->mentioned_allocnos,
                    ira_curr_loop_tree_node->border_allocnos);
  EXECUTE_IF_SET_IN_REG_SET (local_allocno_bitmap, 0, i, bi)
    {
      allocno = allocnos[i];
      regno = ALLOCNO_REGNO (allocno);
      if (ALLOCNO_CAP_MEMBER (allocno) != NULL)
        continue;
      used_p = bitmap_bit_p (used_regno_bitmap, regno);
      bitmap_set_bit (used_regno_bitmap, regno);
      ALLOCNO_SOMEWHERE_RENAMED_P (allocno) = TRUE;
      if (! used_p)
        continue;
      bitmap_set_bit (renamed_regno_bitmap, regno);
      set_allocno_reg (allocno, create_new_reg (ALLOCNO_REG (allocno)));
    }
}

/* The function processes to set up flag somewhere_renamed_p.  */
static void
set_allocno_somewhere_renamed_p (void)
{
  unsigned int regno;
  allocno_t allocno;
  allocno_iterator ai;

  FOR_EACH_ALLOCNO (allocno, ai)
    {
      regno = ALLOCNO_REGNO (allocno);
      if (bitmap_bit_p (renamed_regno_bitmap, regno)
          && REGNO (ALLOCNO_REG (allocno)) == regno)
        ALLOCNO_SOMEWHERE_RENAMED_P (allocno) = TRUE;
    }
}

/* The function returns nonzero if move lists on all edges given in
   vector VEC are equal.  */
static int
eq_edge_move_lists_p (VEC(edge,gc) *vec)
{
  struct move *list;
  int i;

  list = EDGE_I (vec, 0)->aux;
  for (i = EDGE_COUNT (vec) - 1; i > 0; i--)
    if (! eq_move_lists_p (list, EDGE_I (vec, i)->aux))
      return FALSE;
  return TRUE;
}

/* The function looks at all entry edges (if START_P) or exit edges of
   basic block BB and puts move lists at the BB start or end if it is
   possible.  In other words, it decreases code duplication of
   allocno moves.  */
static void
unify_moves (basic_block bb, int start_p)
{
  int i;
  edge e;
  struct move *list;
  VEC(edge,gc) *vec;

  vec = (start_p ? bb->preds : bb->succs);
  if (EDGE_COUNT (vec) == 0 || ! eq_edge_move_lists_p (vec))
    return;
  e = EDGE_I (vec, 0);
  list = e->aux;
  if (! start_p && control_flow_insn_p (BB_END (bb)))
    return;
  e->aux = NULL;
  for (i = EDGE_COUNT (vec) - 1; i > 0; i--)
    {
      e = EDGE_I (vec, i);
      free_move_list (e->aux);
      e->aux = NULL;
    }
  if (start_p)
    at_bb_start[bb->index] = list;
  else
    at_bb_end[bb->index] = list;
}

/* Last move (in move sequence being processed) setting up the
   corresponding hard register.  */
static struct move *hard_regno_last_set[FIRST_PSEUDO_REGISTER];

/* If the element value is equal to CURR_TICK then the corresponding
   element in `hard_regno_last_set' is defined and correct.  */
static int hard_regno_last_set_check[FIRST_PSEUDO_REGISTER];

/* Last move (in move sequence being processed) setting up the
   corresponding allocno.  */
static struct move **allocno_last_set;

/* If the element value is equal to CURR_TICK then the corresponding
   element in . `allocno_last_set' is defined and correct.  */
static int *allocno_last_set_check;

typedef struct move *move_t;

/* Definition of vector of moves.  */
DEF_VEC_P(move_t);
DEF_VEC_ALLOC_P(move_t, heap);

/* This vec contains moves sorted topologically (depth-first) on their
   dependency graph.  */
static VEC(move_t,heap) *move_vec;

/* The variable value is used to check correctness of values of
   elements of arrays `hard_regno_last_set' and
   `allocno_last_set_check'.  */
static int curr_tick;

/* This recursive function traverses dependencies of MOVE and produces
   topological sorting (in depth-first order).  */
static void
traverse_moves (move_t move)
{
  int i;

  if (move->visited_p)
    return;
  move->visited_p = TRUE;
  for (i = move->deps_num - 1; i >= 0; i--)
    traverse_moves (move->deps[i]);
  VEC_safe_push (move_t, heap, move_vec, move);
}

/* The function removes unnecessary moves in the LIST, makes
   topological sorting, and removes cycles on hard reg dependencies by
   introducing new allocnos assigned to memory and additional moves.
   It returns the result move list.  */
static move_t
modify_move_list (move_t list)
{
  int i, n, nregs, hard_regno;
  allocno_t to, from, new_allocno;
  move_t move, new_move, set_move, first, last;

  if (list == NULL)
    return NULL;
  /* Creat move deps.  */
  curr_tick++;
  for (move = list; move != NULL; move = move->next)
    {
      to = move->to;
      if ((hard_regno = ALLOCNO_HARD_REGNO (to)) < 0)
        continue;
      nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (to)];
      for (i = 0; i < nregs; i++)
        {
          hard_regno_last_set[hard_regno + i] = move;
          hard_regno_last_set_check[hard_regno + i] = curr_tick;
        }
    }
  for (move = list; move != NULL; move = move->next)
    {
      from = move->from;
      to = move->to;
      if ((hard_regno = ALLOCNO_HARD_REGNO (from)) >= 0)
        {
          nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (from)];
          for (n = i = 0; i < nregs; i++)
            if (hard_regno_last_set_check[hard_regno + i] == curr_tick
                && (ALLOCNO_REGNO (hard_regno_last_set[hard_regno + i]->to)
                    != ALLOCNO_REGNO (from)))
              n++;
          move->deps = ira_allocate (n * sizeof (move_t));
          for (n = i = 0; i < nregs; i++)
            if (hard_regno_last_set_check[hard_regno + i] == curr_tick
                && (ALLOCNO_REGNO (hard_regno_last_set[hard_regno + i]->to)
                    != ALLOCNO_REGNO (from)))
              move->deps[n++] = hard_regno_last_set[hard_regno + i];
          move->deps_num = n;
        }
    }
  /* Toplogical sorting:  */
  VEC_truncate (move_t, move_vec, 0);
  for (move = list; move != NULL; move = move->next)
    traverse_moves (move);
  last = NULL;
  for (i = (int) VEC_length (move_t, move_vec) - 1; i >= 0; i--)
    {
      move = VEC_index (move_t, move_vec, i);
      move->next = NULL;
      if (last != NULL)
        last->next = move;
      last = move;
    }
  first = VEC_last (move_t, move_vec);
  /* Removing cycles:  */
  curr_tick++;
  VEC_truncate (move_t, move_vec, 0);
  for (move = first; move != NULL; move = move->next)
    {
      from = move->from;
      to = move->to;
      if ((hard_regno = ALLOCNO_HARD_REGNO (from)) >= 0)
        {
          nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (from)];
          for (i = 0; i < nregs; i++)
            if (hard_regno_last_set_check[hard_regno + i] == curr_tick
                && ALLOCNO_HARD_REGNO
                   (hard_regno_last_set[hard_regno + i]->to) >= 0)
              {
                set_move = hard_regno_last_set[hard_regno + i];
                /* It does not matter what loop_tree_node (of TO or
                   FROM) to use for the new allocno because of
                   subsequent IRA internal representation
                   flattening.  */
                new_allocno
                  = create_allocno (ALLOCNO_REGNO (set_move->to), FALSE,
                                    ALLOCNO_LOOP_TREE_NODE (set_move->to));
                ALLOCNO_MODE (new_allocno) = ALLOCNO_MODE (set_move->to);
                set_allocno_cover_class (new_allocno,
                                         ALLOCNO_COVER_CLASS (set_move->to));
                ALLOCNO_ASSIGNED_P (new_allocno) = TRUE;
                ALLOCNO_HARD_REGNO (new_allocno) = -1;
                ALLOCNO_REG (new_allocno)
                  = create_new_reg (ALLOCNO_REG (set_move->to));
                ALLOCNO_CONFLICT_ID (new_allocno) = ALLOCNO_NUM (new_allocno);
                /* Make it possibly conflicting with all earlier
                   created allocnos.  Cases where temporary allocnos
                   created to remove the cycles are quite rare.  */
                ALLOCNO_MIN (new_allocno) = 0;
                ALLOCNO_MAX (new_allocno) = allocnos_num - 1;
                new_move = create_move (set_move->to, new_allocno);
                set_move->to = new_allocno;
                VEC_safe_push (move_t, heap, move_vec, new_move);
                move_loops_num++;
                if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
                  fprintf (ira_dump_file,
                           "    Creating temporary allocno a%dr%d\n",
                           ALLOCNO_NUM (new_allocno),
                           REGNO (ALLOCNO_REG (new_allocno)));
              }
        }
      if ((hard_regno = ALLOCNO_HARD_REGNO (to)) < 0)
        continue;
      nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (to)];
      for (i = 0; i < nregs; i++)
        {
          hard_regno_last_set[hard_regno + i] = move;
          hard_regno_last_set_check[hard_regno + i] = curr_tick;
        }
    }
  for (i = (int) VEC_length (move_t, move_vec) - 1; i >= 0; i--)
    {
      move = VEC_index (move_t, move_vec, i);
      move->next = NULL;
      last->next = move;
      last = move;
    }
  return first;
}

/* The function generates RTX move insns from the move list LIST.  It
   updates allocation cost using move execution frequency FREQ.  */
static rtx
emit_move_list (move_t list, int freq)
{
  int cost;
  rtx result, insn;
  enum machine_mode mode;
  enum reg_class cover_class;

  start_sequence ();
  for (; list != NULL; list = list->next)
    {
      start_sequence ();
      emit_move_insn (ALLOCNO_REG (list->to), ALLOCNO_REG (list->from));
      list->insn = get_insns ();
      end_sequence ();
      /* The reload needs to have set up insn codes.  If the reload
         sets up insn codes by itself, it may fail because insns will
         have hard registers instead of pseudos and there may be no
         machine insn with given hard registers.  */
      for (insn = list->insn; insn != NULL_RTX; insn = NEXT_INSN (insn))
        recog_memoized (insn);
      emit_insn (list->insn);
      mode = ALLOCNO_MODE (list->to);
      cover_class = ALLOCNO_COVER_CLASS (list->to);
      cost = 0;
      if (ALLOCNO_HARD_REGNO (list->to) < 0)
        {
          if (ALLOCNO_HARD_REGNO (list->from) >= 0)
            {
              cost = memory_move_cost[mode][cover_class][0] * freq;
              store_cost += cost;
            }
        }
      else if (ALLOCNO_HARD_REGNO (list->from) < 0)
        {
          if (ALLOCNO_HARD_REGNO (list->to) >= 0)
            {
              cost = memory_move_cost[mode][cover_class][0] * freq;
              load_cost += cost;
            }
        }
      else
        {
          cost = register_move_cost[mode][cover_class][cover_class] * freq;
          shuffle_cost += cost;
        }
      overall_cost += cost;
    }
  result = get_insns ();
  end_sequence ();
  return result;
}

/* The function generates RTX move insns from move lists attached to
   basic blocks and edges.  */
static void
emit_moves (void)
{
  basic_block bb;
  edge_iterator ei;
  edge e;
  rtx insns, tmp;

  FOR_EACH_BB (bb)
    {
      if (at_bb_start[bb->index] != NULL)
        {
          at_bb_start[bb->index] = modify_move_list (at_bb_start[bb->index]);
          insns = emit_move_list (at_bb_start[bb->index],
                                  REG_FREQ_FROM_BB (bb));
          tmp = BB_HEAD (bb);
          if (LABEL_P (tmp))
            tmp = NEXT_INSN (tmp);
          if (NOTE_INSN_BASIC_BLOCK_P (tmp))
            tmp = NEXT_INSN (tmp);
          if (tmp == BB_HEAD (bb))
            emit_insn_before (insns, tmp);
          else if (tmp != NULL_RTX)
            emit_insn_after (insns, PREV_INSN (tmp));
          else
            emit_insn_after (insns, get_last_insn ());
        }

      if (at_bb_end[bb->index] != NULL)
        {
          at_bb_end[bb->index] = modify_move_list (at_bb_end[bb->index]);
          insns = emit_move_list (at_bb_end[bb->index], REG_FREQ_FROM_BB (bb));
          ira_assert (! control_flow_insn_p (BB_END (bb)));
          emit_insn_after (insns, BB_END (bb));
        }

      FOR_EACH_EDGE (e, ei, bb->succs)
        {
          if (e->aux == NULL)
            continue;
          ira_assert ((e->flags & EDGE_ABNORMAL) == 0
                      || ! EDGE_CRITICAL_P (e));
          e->aux = modify_move_list (e->aux);
          insert_insn_on_edge
            (emit_move_list (e->aux,
                             REG_FREQ_FROM_EDGE_FREQ (EDGE_FREQUENCY (e))),
             e);
          if (e->src->next_bb != e->dest)
            additional_jumps_num++;
        }
    }
}

/* Update costs of A and corresponding allocnos on upper levels on the
   loop tree from reading (if READ_P) or writing A on an execution
   path with FREQ.  */
static void
update_costs (allocno_t a, int read_p, int freq)
{
  loop_tree_node_t father;

  for (;;)
    {
      ALLOCNO_NREFS (a)++;
      ALLOCNO_FREQ (a) += freq;
      ALLOCNO_MEMORY_COST (a)
        += (memory_move_cost[ALLOCNO_MODE (a)][ALLOCNO_COVER_CLASS (a)]
            [read_p ? 1 : 0] * freq);
      if ((father = ALLOCNO_LOOP_TREE_NODE (a)->father) == NULL
          || (a = father->regno_allocno_map[ALLOCNO_REGNO (a)]) == NULL)
        break;
    }
}

/* The function processes moves from LIST with execution FREQ to add
   ranges, copies, and modify costs for allocnos involved in the
   moves.  All regnos living through the list is in LIVE_THROUGH, and
   the loop tree node used to find corresponding allocnos is NODE.  */
static void
add_range_and_copies_from_move_list (move_t list, loop_tree_node_t node,
                                     bitmap live_through, int freq)
{
  int start, n;
  unsigned int regno;
  move_t move;
  allocno_t to, from, a;
  copy_t cp;
  allocno_live_range_t r;
  bitmap_iterator bi;
  HARD_REG_SET hard_regs_live;

  if (list == NULL)
    return;
  n = 0;
  EXECUTE_IF_SET_IN_BITMAP (live_through, FIRST_PSEUDO_REGISTER, regno, bi)
    n++;
  REG_SET_TO_HARD_REG_SET (hard_regs_live, live_through);
  /* This is a trick to guarantee that new ranges is not merged with
     the old ones.  */
  max_point++;
  start = max_point;
  for (move = list; move != NULL; move = move->next)
    {
      from = move->from;
      to = move->to;
      if (ALLOCNO_CONFLICT_ALLOCNO_ARRAY (to) == NULL)
        {
          if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
            fprintf (ira_dump_file, "    Allocate conflicts for a%dr%d\n",
                     ALLOCNO_NUM (to), REGNO (ALLOCNO_REG (to)));
          allocate_allocno_conflicts (to, n);
        }
      bitmap_clear_bit (live_through, ALLOCNO_REGNO (from));
      bitmap_clear_bit (live_through, ALLOCNO_REGNO (to));
      IOR_HARD_REG_SET (ALLOCNO_CONFLICT_HARD_REGS (from), hard_regs_live);
      IOR_HARD_REG_SET (ALLOCNO_CONFLICT_HARD_REGS (to), hard_regs_live);
      IOR_HARD_REG_SET (ALLOCNO_TOTAL_CONFLICT_HARD_REGS (from),
                        hard_regs_live);
      IOR_HARD_REG_SET (ALLOCNO_TOTAL_CONFLICT_HARD_REGS (to), hard_regs_live);
      update_costs (from, TRUE, freq);
      update_costs (to, FALSE, freq);
      cp = add_allocno_copy (from, to, freq, move->insn, NULL);
      if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
        fprintf (ira_dump_file, "    Adding cp%d:a%dr%d-a%dr%d\n",
                 cp->num, ALLOCNO_NUM (cp->first),
                 REGNO (ALLOCNO_REG (cp->first)), ALLOCNO_NUM (cp->second),
                 REGNO (ALLOCNO_REG (cp->second)));
      r = ALLOCNO_LIVE_RANGES (from);
      if (r == NULL || r->finish >= 0)
        {
          ALLOCNO_LIVE_RANGES (from)
            = create_allocno_live_range (from, start, max_point, r);
          if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
            fprintf (ira_dump_file,
                     "    Adding range [%d..%d] to allocno a%dr%d\n",
                     start, max_point, ALLOCNO_NUM (from),
                     REGNO (ALLOCNO_REG (from)));
        }
      else
        r->finish = max_point;
      max_point++;
      ALLOCNO_LIVE_RANGES (to)
        = create_allocno_live_range (to, max_point, -1,
                                     ALLOCNO_LIVE_RANGES (to));
      max_point++;
    }
  for (move = list; move != NULL; move = move->next)
    {
      r = ALLOCNO_LIVE_RANGES (move->to);
      if (r->finish < 0)
        {
          r->finish = max_point - 1;
          if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
            fprintf (ira_dump_file,
                     "    Adding range [%d..%d] to allocno a%dr%d\n",
                     r->start, r->finish, ALLOCNO_NUM (move->to),
                     REGNO (ALLOCNO_REG (move->to)));
        }
    }
  EXECUTE_IF_SET_IN_BITMAP (live_through, FIRST_PSEUDO_REGISTER, regno, bi)
    {
      a = node->regno_allocno_map[regno];
      if (ALLOCNO_MEM_OPTIMIZED_DEST (a) == NULL)
        {
          ALLOCNO_LIVE_RANGES (a)
            = create_allocno_live_range (a, start, max_point - 1,
                                         ALLOCNO_LIVE_RANGES (a));
          if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
            fprintf
              (ira_dump_file,
               "    Adding range [%d..%d] to live through allocno a%dr%d\n",
               start, max_point - 1, ALLOCNO_NUM (a), REGNO (ALLOCNO_REG (a)));
        }
    }
}

/* The function processes all move list to add ranges, conflicts,
   copies, and modify costs for allocnos involved in the moves.  */
static void
add_ranges_and_copies (void)
{
  basic_block bb;
  edge_iterator ei;
  edge e;
  loop_tree_node_t node;
  bitmap live_through;

  live_through = ira_allocate_bitmap ();
  FOR_EACH_BB (bb)
    {
      /* It does not matter what loop_tree_node (of source or
         destination block) to use for searching allocnos by their
         regnos because of subsequent IR flattening.  */
      node = IRA_BB_NODE (bb)->father;
      bitmap_copy (live_through, DF_LR_IN (bb));
      add_range_and_copies_from_move_list
        (at_bb_start[bb->index], node, live_through, REG_FREQ_FROM_BB (bb));
      bitmap_copy (live_through, DF_LR_OUT (bb));
      add_range_and_copies_from_move_list
        (at_bb_end[bb->index], node, live_through, REG_FREQ_FROM_BB (bb));
      FOR_EACH_EDGE (e, ei, bb->succs)
        {
          bitmap_and (live_through, DF_LR_IN (e->dest), DF_LR_OUT (bb));
          add_range_and_copies_from_move_list
            (e->aux, node, live_through,
             REG_FREQ_FROM_EDGE_FREQ (EDGE_FREQUENCY (e)));
        }
    }
  ira_free_bitmap (live_through);
}

/* The entry function changes code and generates shuffling allocnos on
   region borders for the regional (LOOPS_P is TRUE in this case)
   register allocation.  */
void
ira_emit (int loops_p)
{
  basic_block bb;
  edge_iterator ei;
  edge e;
  allocno_t a;
  allocno_iterator ai;

  FOR_EACH_ALLOCNO (a, ai)
    ALLOCNO_REG (a) = regno_reg_rtx[ALLOCNO_REGNO (a)];
  if (! loops_p)
    return;
  at_bb_start = ira_allocate (sizeof (move_t) * last_basic_block);
  memset (at_bb_start, 0, sizeof (move_t) * last_basic_block);
  at_bb_end = ira_allocate (sizeof (move_t) * last_basic_block);
  memset (at_bb_end, 0, sizeof (move_t) * last_basic_block);
  local_allocno_bitmap = ira_allocate_bitmap ();
  used_regno_bitmap = ira_allocate_bitmap ();
  renamed_regno_bitmap = ira_allocate_bitmap ();
  max_regno_before_changing = max_reg_num ();
  traverse_loop_tree (TRUE, ira_loop_tree_root, change_loop, NULL);
  set_allocno_somewhere_renamed_p ();
  ira_free_bitmap (used_regno_bitmap);
  ira_free_bitmap (renamed_regno_bitmap);
  ira_free_bitmap (local_allocno_bitmap);
  FOR_EACH_BB (bb)
    {
      at_bb_start[bb->index] = NULL;
      at_bb_end[bb->index] = NULL;
      FOR_EACH_EDGE (e, ei, bb->succs)
        if (e->dest != EXIT_BLOCK_PTR)
          generate_edge_moves (e);
    }
  allocno_last_set = ira_allocate (sizeof (move_t) * max_reg_num ());
  allocno_last_set_check = ira_allocate (sizeof (int) * max_reg_num ());
  memset (allocno_last_set_check, 0, sizeof (int) * max_reg_num ());
  memset (hard_regno_last_set_check, 0, sizeof (hard_regno_last_set_check));
  curr_tick = 0;
  FOR_EACH_BB (bb)
    unify_moves (bb, TRUE);
  FOR_EACH_BB (bb)
    unify_moves (bb, FALSE);
  move_vec = VEC_alloc (move_t, heap, allocnos_num);
  emit_moves ();
  add_ranges_and_copies ();
  /* Clean up: */
  FOR_EACH_BB (bb)
    {
      free_move_list (at_bb_start[bb->index]);
      free_move_list (at_bb_end[bb->index]);
      FOR_EACH_EDGE (e, ei, bb->succs)
        {
          free_move_list (e->aux);
          e->aux = NULL;
        }
    }
  VEC_free (move_t, heap, move_vec);
  ira_free (allocno_last_set_check);
  ira_free (allocno_last_set);
  commit_edge_insertions ();
  ira_free (at_bb_end);
  ira_free (at_bb_start);
}