[thirdparty/gcc.git] / gcc / lra-coalesce.c

/* Coalesce spilled pseudos.
   Copyright (C) 2010-2022 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/>.	 */


/* This file contains a pass making some simple RTL code
   transformations by coalescing pseudos to remove some move insns.

   Spilling pseudos in LRA can create memory-memory moves.  We should
   remove potential memory-memory moves before the next constraint
   pass because the constraint pass will generate additional insns for
   such moves and all these insns will be hard to remove afterwards.

   Here we coalesce only spilled pseudos.  Coalescing non-spilled
   pseudos (with different hard regs) might result in spilling
   additional pseudos because of possible conflicts with other
   non-spilled pseudos and, as a consequence, in more constraint
   passes and even LRA infinite cycling.  Trivial the same hard
   register moves will be removed by subsequent compiler passes.

   We don't coalesce special reload pseudos.  It complicates LRA code
   a lot without visible generated code improvement.

   The pseudo live-ranges are used to find conflicting pseudos during
   coalescing.

   Most frequently executed moves is tried to be coalesced first.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "rtl.h"
#include "predict.h"
#include "df.h"
#include "insn-config.h"
#include "regs.h"
#include "memmodel.h"
#include "ira.h"
#include "recog.h"
#include "lra-int.h"

/* Arrays whose elements represent the first and the next pseudo
   (regno) in the coalesced pseudos group to which given pseudo (its
   regno is the index) belongs.	 The next of the last pseudo in the
   group refers to the first pseudo in the group, in other words the
   group is represented by a cyclic list.  */
static int *first_coalesced_pseudo, *next_coalesced_pseudo;

/* The function is used to sort moves according to their execution
   frequencies.	 */
static int
move_freq_compare_func (const void *v1p, const void *v2p)
{
  rtx_insn *mv1 = *(rtx_insn * const *) v1p;
  rtx_insn *mv2 = *(rtx_insn * const *) v2p;
  int pri1, pri2;

  pri1 = REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv1));
  pri2 = REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv2));
  if (pri2 - pri1)
    return pri2 - pri1;

  /* If frequencies are equal, sort by moves, so that the results of
     qsort leave nothing to chance.  */
  return (int) INSN_UID (mv1) - (int) INSN_UID (mv2);
}

/* Pseudos which go away after coalescing.  */
static bitmap_head coalesced_pseudos_bitmap;

/* Merge two sets of coalesced pseudos given correspondingly by
   pseudos REGNO1 and REGNO2 (more accurately merging REGNO2 group
   into REGNO1 group).	Set up COALESCED_PSEUDOS_BITMAP.  */
static void
merge_pseudos (int regno1, int regno2)
{
  int regno, first, first2, last, next;

  first = first_coalesced_pseudo[regno1];
  if ((first2 = first_coalesced_pseudo[regno2]) == first)
    return;
  for (last = regno2, regno = next_coalesced_pseudo[regno2];;
       regno = next_coalesced_pseudo[regno])
    {
      first_coalesced_pseudo[regno] = first;
      bitmap_set_bit (&coalesced_pseudos_bitmap, regno);
      if (regno == regno2)
	break;
      last = regno;
    }
  next = next_coalesced_pseudo[first];
  next_coalesced_pseudo[first] = regno2;
  next_coalesced_pseudo[last] = next;
  lra_reg_info[first].live_ranges
    = (lra_merge_live_ranges
       (lra_reg_info[first].live_ranges,
	lra_copy_live_range_list (lra_reg_info[first2].live_ranges)));
  if (partial_subreg_p (lra_reg_info[first].biggest_mode,
			lra_reg_info[first2].biggest_mode))
    lra_reg_info[first].biggest_mode = lra_reg_info[first2].biggest_mode;
}

/* Change pseudos in *LOC on their coalescing group
   representatives.  */
static bool
substitute (rtx *loc)
{
  int i, regno;
  const char *fmt;
  enum rtx_code code;
  bool res;

  if (*loc == NULL_RTX)
    return false;
  code = GET_CODE (*loc);
  if (code == REG)
    {
      regno = REGNO (*loc);
      if (regno < FIRST_PSEUDO_REGISTER
	  || first_coalesced_pseudo[regno] == regno)
	return false;
      *loc = regno_reg_rtx[first_coalesced_pseudo[regno]];
      return true;
    }

  res = false;
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'e')
	{
	  if (substitute (&XEXP (*loc, i)))
	    res = true;
	}
      else if (fmt[i] == 'E')
	{
	  int j;

	  for (j = XVECLEN (*loc, i) - 1; j >= 0; j--)
	    if (substitute (&XVECEXP (*loc, i, j)))
	      res = true;
	}
    }
  return res;
}

/* Specialize "substitute" for use on an insn.  This can't change
   the insn ptr, just the contents of the insn.  */

static bool
substitute_within_insn (rtx_insn *insn)
{
  rtx loc = insn;
  return substitute (&loc);
}

/* The current iteration (1, 2, ...) of the coalescing pass.  */
int lra_coalesce_iter;

/* Return true if the move involving REGNO1 and REGNO2 is a potential
   memory-memory move.	*/
static bool
mem_move_p (int regno1, int regno2)
{
  return reg_renumber[regno1] < 0 && reg_renumber[regno2] < 0;
}

/* Pseudos used instead of the coalesced pseudos.  */
static bitmap_head used_pseudos_bitmap;

/* Set up USED_PSEUDOS_BITMAP, and update LR_BITMAP (a BB live info
   bitmap).  */
static void
update_live_info (bitmap lr_bitmap)
{
  unsigned int j;
  bitmap_iterator bi;

  bitmap_clear (&used_pseudos_bitmap);
  EXECUTE_IF_AND_IN_BITMAP (&coalesced_pseudos_bitmap, lr_bitmap,
			    FIRST_PSEUDO_REGISTER, j, bi)
    bitmap_set_bit (&used_pseudos_bitmap, first_coalesced_pseudo[j]);
  if (! bitmap_empty_p (&used_pseudos_bitmap))
    {
      bitmap_and_compl_into (lr_bitmap, &coalesced_pseudos_bitmap);
      bitmap_ior_into (lr_bitmap, &used_pseudos_bitmap);
    }
}

/* Return true if pseudo REGNO can be potentially coalesced.  */
static bool
coalescable_pseudo_p (int regno)
{
  lra_assert (regno >= FIRST_PSEUDO_REGISTER);
  return (/* We don't want to coalesce regnos with equivalences, at
	     least without updating this info.  */
	  ira_reg_equiv[regno].constant == NULL_RTX
	  && ira_reg_equiv[regno].memory == NULL_RTX
	  && ira_reg_equiv[regno].invariant == NULL_RTX);
}

/* The major function for aggressive pseudo coalescing of moves only
   if the both pseudos were spilled and not special reload pseudos.  */
bool
lra_coalesce (void)
{
  basic_block bb;
  rtx_insn *mv, *insn, *next, **sorted_moves;
  rtx set;
  int i, mv_num, sregno, dregno;
  int coalesced_moves;
  int max_regno = max_reg_num ();
  bitmap_head involved_insns_bitmap;
  
  timevar_push (TV_LRA_COALESCE);

  if (lra_dump_file != NULL)
    fprintf (lra_dump_file,
	     "\n********** Pseudos coalescing #%d: **********\n\n",
	     ++lra_coalesce_iter);
  first_coalesced_pseudo = XNEWVEC (int, max_regno);
  next_coalesced_pseudo = XNEWVEC (int, max_regno);
  for (i = 0; i < max_regno; i++)
    first_coalesced_pseudo[i] = next_coalesced_pseudo[i] = i;
  sorted_moves = XNEWVEC (rtx_insn *, get_max_uid ());
  mv_num = 0;
  /* Collect moves.  */
  coalesced_moves = 0;
  FOR_EACH_BB_FN (bb, cfun)
    {
      FOR_BB_INSNS_SAFE (bb, insn, next)
	if (INSN_P (insn)
	    && (set = single_set (insn)) != NULL_RTX
	    && REG_P (SET_DEST (set)) && REG_P (SET_SRC (set))
	    && (sregno = REGNO (SET_SRC (set))) >= FIRST_PSEUDO_REGISTER
	    && (dregno = REGNO (SET_DEST (set))) >= FIRST_PSEUDO_REGISTER
	    && mem_move_p (sregno, dregno)
	    && coalescable_pseudo_p (sregno) && coalescable_pseudo_p (dregno)
	    && ! side_effects_p (set)
	    && !(lra_intersected_live_ranges_p
		 (lra_reg_info[sregno].live_ranges,
		  lra_reg_info[dregno].live_ranges)))
	  sorted_moves[mv_num++] = insn;
    }
  qsort (sorted_moves, mv_num, sizeof (rtx), move_freq_compare_func);
  /* Coalesced copies, most frequently executed first.	*/
  bitmap_initialize (&coalesced_pseudos_bitmap, &reg_obstack);
  bitmap_initialize (&involved_insns_bitmap, &reg_obstack);
  for (i = 0; i < mv_num; i++)
    {
      mv = sorted_moves[i];
      set = single_set (mv);
      lra_assert (set != NULL && REG_P (SET_SRC (set))
		  && REG_P (SET_DEST (set)));
      sregno = REGNO (SET_SRC (set));
      dregno = REGNO (SET_DEST (set));
      if (first_coalesced_pseudo[sregno] == first_coalesced_pseudo[dregno])
	{
	  coalesced_moves++;
	  if (lra_dump_file != NULL)
	    fprintf
	      (lra_dump_file, "      Coalescing move %i:r%d-r%d (freq=%d)\n",
	       INSN_UID (mv), sregno, dregno,
	       REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv)));
	  /* We updated involved_insns_bitmap when doing the merge.  */
	}
      else if (!(lra_intersected_live_ranges_p
		 (lra_reg_info[first_coalesced_pseudo[sregno]].live_ranges,
		  lra_reg_info[first_coalesced_pseudo[dregno]].live_ranges)))
	{
	  coalesced_moves++;
	  if (lra_dump_file != NULL)
	    fprintf
	      (lra_dump_file,
	       "  Coalescing move %i:r%d(%d)-r%d(%d) (freq=%d)\n",
	       INSN_UID (mv), sregno, ORIGINAL_REGNO (SET_SRC (set)),
	       dregno, ORIGINAL_REGNO (SET_DEST (set)),
	       REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv)));
	  bitmap_ior_into (&involved_insns_bitmap,
			   &lra_reg_info[sregno].insn_bitmap);
	  bitmap_ior_into (&involved_insns_bitmap,
			   &lra_reg_info[dregno].insn_bitmap);
	  merge_pseudos (sregno, dregno);
	}
    }
  bitmap_initialize (&used_pseudos_bitmap, &reg_obstack);
  FOR_EACH_BB_FN (bb, cfun)
    {
      update_live_info (df_get_live_in (bb));
      update_live_info (df_get_live_out (bb));
      FOR_BB_INSNS_SAFE (bb, insn, next)
	if (INSN_P (insn)
	    && bitmap_bit_p (&involved_insns_bitmap, INSN_UID (insn)))
	  {
	    if (! substitute_within_insn (insn))
	      continue;
	    lra_update_insn_regno_info (insn);
	    if ((set = single_set (insn)) != NULL_RTX && set_noop_p (set))
	      {
		/* Coalesced move.  */
		if (lra_dump_file != NULL)
		  fprintf (lra_dump_file, "	 Removing move %i (freq=%d)\n",
			   INSN_UID (insn),
			   REG_FREQ_FROM_BB (BLOCK_FOR_INSN (insn)));
		lra_set_insn_deleted (insn);
	      }
	  }
    }
  /* If we have situation after inheritance pass:

     r1 <- p1   insn originally setting p1
     i1 <- r1   setting inheritance i1 from reload r1
       ...
     ... <- ... p2 ... dead p2
     ..
     p1 <- i1
     r2 <- i1
     ...<- ... r2 ...

     And we are coalescing p1 and p2 using p1.  In this case i1 and p1
     should have different values, otherwise they can get the same
     hard reg and this is wrong for insn using p2 before coalescing.
     The situation even can be more complicated when new reload
     pseudos occur after the inheriatnce.  So invalidate the result
     pseudos.  */
  for (i = 0; i < max_regno; i++)
    if (first_coalesced_pseudo[i] == i
	&& first_coalesced_pseudo[i] != next_coalesced_pseudo[i])
      {
	lra_set_regno_unique_value (i);
	if (lra_dump_file != NULL)
	  fprintf (lra_dump_file,
		   "	 Make unique value for coalescing result r%d\n", i);
      }
  bitmap_clear (&used_pseudos_bitmap);
  bitmap_clear (&involved_insns_bitmap);
  bitmap_clear (&coalesced_pseudos_bitmap);
  if (lra_dump_file != NULL && coalesced_moves != 0)
    fprintf (lra_dump_file, "Coalesced Moves = %d\n", coalesced_moves);
  free (sorted_moves);
  free (next_coalesced_pseudo);
  free (first_coalesced_pseudo);
  timevar_pop (TV_LRA_COALESCE);
  return coalesced_moves != 0;
}
Commit	Line	Data
55a2c322	1	/* Coalesce spilled pseudos.
7adcbafe	2	Copyright (C) 2010-2022 Free Software Foundation, Inc.
55a2c322 VM	3	Contributed by Vladimir Makarov <vmakarov@redhat.com>.
	4
	5	This file is part of GCC.
	6
	7	GCC is free software; you can redistribute it and/or modify it under
	8	the terms of the GNU General Public License as published by the Free
	9	Software Foundation; either version 3, or (at your option) any later
	10	version.
	11
	12	GCC is distributed in the hope that it will be useful, but WITHOUT ANY
	13	WARRANTY; without even the implied warranty of MERCHANTABILITY or
	14	FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	15	for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with GCC; see the file COPYING3. If not see
	19	<http://www.gnu.org/licenses/>. */
	20
	21
	22	/* This file contains a pass making some simple RTL code
	23	transformations by coalescing pseudos to remove some move insns.
	24
	25	Spilling pseudos in LRA can create memory-memory moves. We should
	26	remove potential memory-memory moves before the next constraint
	27	pass because the constraint pass will generate additional insns for
	28	such moves and all these insns will be hard to remove afterwards.
	29
	30	Here we coalesce only spilled pseudos. Coalescing non-spilled
	31	pseudos (with different hard regs) might result in spilling
	32	additional pseudos because of possible conflicts with other
	33	non-spilled pseudos and, as a consequence, in more constraint
	34	passes and even LRA infinite cycling. Trivial the same hard
	35	register moves will be removed by subsequent compiler passes.
	36
	37	We don't coalesce special reload pseudos. It complicates LRA code
	38	a lot without visible generated code improvement.
	39
	40	The pseudo live-ranges are used to find conflicting pseudos during
	41	coalescing.
	42
	43	Most frequently executed moves is tried to be coalesced first. */
	44
	45	#include "config.h"
	46	#include "system.h"
	47	#include "coretypes.h"
c7131fb2	48	#include "backend.h"
55a2c322	49	#include "rtl.h"
957060b5	50	#include "predict.h"
c7131fb2	51	#include "df.h"
55a2c322	52	#include "insn-config.h"
957060b5	53	#include "regs.h"
4d0cdd0c	54	#include "memmodel.h"
957060b5	55	#include "ira.h"
55a2c322	56	#include "recog.h"
55a2c322	57	#include "lra-int.h"
55a2c322 VM	58
	59	/* Arrays whose elements represent the first and the next pseudo
	60	(regno) in the coalesced pseudos group to which given pseudo (its
	61	regno is the index) belongs. The next of the last pseudo in the
	62	group refers to the first pseudo in the group, in other words the
	63	group is represented by a cyclic list. */
	64	static int first_coalesced_pseudo, next_coalesced_pseudo;
	65
	66	/* The function is used to sort moves according to their execution
	67	frequencies. */
	68	static int
	69	move_freq_compare_func (const void v1p, const void v2p)
	70	{
cfa434f6 DM	71	rtx_insn mv1 = (rtx_insn * const *) v1p;
cfa434f6 DM	72	rtx_insn mv2 = (rtx_insn * const *) v2p;
55a2c322	73	int pri1, pri2;
f4eafc30	74
fef37404 VM	75	pri1 = REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv1));
fef37404 VM	76	pri2 = REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv2));
55a2c322 VM	77	if (pri2 - pri1)
	78	return pri2 - pri1;
	79
	80	/* If frequencies are equal, sort by moves, so that the results of
	81	qsort leave nothing to chance. */
	82	return (int) INSN_UID (mv1) - (int) INSN_UID (mv2);
	83	}
	84
	85	/* Pseudos which go away after coalescing. */
	86	static bitmap_head coalesced_pseudos_bitmap;
	87
	88	/* Merge two sets of coalesced pseudos given correspondingly by
	89	pseudos REGNO1 and REGNO2 (more accurately merging REGNO2 group
	90	into REGNO1 group). Set up COALESCED_PSEUDOS_BITMAP. */
	91	static void
	92	merge_pseudos (int regno1, int regno2)
	93	{
	94	int regno, first, first2, last, next;
	95
	96	first = first_coalesced_pseudo[regno1];
	97	if ((first2 = first_coalesced_pseudo[regno2]) == first)
	98	return;
	99	for (last = regno2, regno = next_coalesced_pseudo[regno2];;
	100	regno = next_coalesced_pseudo[regno])
	101	{
	102	first_coalesced_pseudo[regno] = first;
	103	bitmap_set_bit (&coalesced_pseudos_bitmap, regno);
	104	if (regno == regno2)
	105	break;
	106	last = regno;
	107	}
	108	next = next_coalesced_pseudo[first];
	109	next_coalesced_pseudo[first] = regno2;
	110	next_coalesced_pseudo[last] = next;
	111	lra_reg_info[first].live_ranges
	112	= (lra_merge_live_ranges
	113	(lra_reg_info[first].live_ranges,
	114	lra_copy_live_range_list (lra_reg_info[first2].live_ranges)));
bd4288c0 RS	115	if (partial_subreg_p (lra_reg_info[first].biggest_mode,
bd4288c0 RS	116	lra_reg_info[first2].biggest_mode))
55a2c322 VM	117	lra_reg_info[first].biggest_mode = lra_reg_info[first2].biggest_mode;
	118	}
	119
	120	/* Change pseudos in *LOC on their coalescing group
	121	representatives. */
	122	static bool
	123	substitute (rtx *loc)
	124	{
	125	int i, regno;
	126	const char *fmt;
	127	enum rtx_code code;
	128	bool res;
	129
	130	if (*loc == NULL_RTX)
	131	return false;
	132	code = GET_CODE (*loc);
	133	if (code == REG)
	134	{
	135	regno = REGNO (*loc);
	136	if (regno < FIRST_PSEUDO_REGISTER
	137	\|\| first_coalesced_pseudo[regno] == regno)
	138	return false;
	139	*loc = regno_reg_rtx[first_coalesced_pseudo[regno]];
	140	return true;
	141	}
	142
	143	res = false;
	144	fmt = GET_RTX_FORMAT (code);
	145	for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
	146	{
	147	if (fmt[i] == 'e')
	148	{
	149	if (substitute (&XEXP (*loc, i)))
	150	res = true;
	151	}
	152	else if (fmt[i] == 'E')
	153	{
	154	int j;
	155
	156	for (j = XVECLEN (*loc, i) - 1; j >= 0; j--)
	157	if (substitute (&XVECEXP (*loc, i, j)))
	158	res = true;
	159	}
	160	}
	161	return res;
	162	}
	163
cfa434f6 DM	164	/* Specialize "substitute" for use on an insn. This can't change
	165	the insn ptr, just the contents of the insn. */
	166
	167	static bool
	168	substitute_within_insn (rtx_insn *insn)
	169	{
	170	rtx loc = insn;
	171	return substitute (&loc);
	172	}
	173
55a2c322 VM	174	/* The current iteration (1, 2, ...) of the coalescing pass. */
	175	int lra_coalesce_iter;
	176
	177	/* Return true if the move involving REGNO1 and REGNO2 is a potential
	178	memory-memory move. */
	179	static bool
	180	mem_move_p (int regno1, int regno2)
	181	{
	182	return reg_renumber[regno1] < 0 && reg_renumber[regno2] < 0;
	183	}
	184
	185	/* Pseudos used instead of the coalesced pseudos. */
	186	static bitmap_head used_pseudos_bitmap;
	187
	188	/* Set up USED_PSEUDOS_BITMAP, and update LR_BITMAP (a BB live info
	189	bitmap). */
	190	static void
	191	update_live_info (bitmap lr_bitmap)
	192	{
	193	unsigned int j;
	194	bitmap_iterator bi;
	195
	196	bitmap_clear (&used_pseudos_bitmap);
	197	EXECUTE_IF_AND_IN_BITMAP (&coalesced_pseudos_bitmap, lr_bitmap,
	198	FIRST_PSEUDO_REGISTER, j, bi)
	199	bitmap_set_bit (&used_pseudos_bitmap, first_coalesced_pseudo[j]);
	200	if (! bitmap_empty_p (&used_pseudos_bitmap))
	201	{
	202	bitmap_and_compl_into (lr_bitmap, &coalesced_pseudos_bitmap);
	203	bitmap_ior_into (lr_bitmap, &used_pseudos_bitmap);
	204	}
	205	}
	206
72ea0d47	207	/* Return true if pseudo REGNO can be potentially coalesced. */
55a2c322	208	static bool
72ea0d47	209	coalescable_pseudo_p (int regno)
55a2c322 VM	210	{
55a2c322 VM	211	lra_assert (regno >= FIRST_PSEUDO_REGISTER);
72ea0d47	212	return (/* We don't want to coalesce regnos with equivalences, at
55a2c322	213	least without updating this info. */
72ea0d47	214	ira_reg_equiv[regno].constant == NULL_RTX
55a2c322 VM	215	&& ira_reg_equiv[regno].memory == NULL_RTX
	216	&& ira_reg_equiv[regno].invariant == NULL_RTX);
	217	}
	218
	219	/* The major function for aggressive pseudo coalescing of moves only
	220	if the both pseudos were spilled and not special reload pseudos. */
	221	bool
	222	lra_coalesce (void)
	223	{
	224	basic_block bb;
cfa434f6 DM	225	rtx_insn mv, insn, next, *sorted_moves;
cfa434f6 DM	226	rtx set;
72ea0d47	227	int i, mv_num, sregno, dregno;
55a2c322 VM	228	int coalesced_moves;
55a2c322 VM	229	int max_regno = max_reg_num ();
72ea0d47	230	bitmap_head involved_insns_bitmap;
35b707ff	231
55a2c322 VM	232	timevar_push (TV_LRA_COALESCE);
	233
	234	if (lra_dump_file != NULL)
	235	fprintf (lra_dump_file,
	236	"\n******** Pseudos coalescing #%d: ********\n\n",
	237	++lra_coalesce_iter);
	238	first_coalesced_pseudo = XNEWVEC (int, max_regno);
	239	next_coalesced_pseudo = XNEWVEC (int, max_regno);
	240	for (i = 0; i < max_regno; i++)
	241	first_coalesced_pseudo[i] = next_coalesced_pseudo[i] = i;
cfa434f6	242	sorted_moves = XNEWVEC (rtx_insn *, get_max_uid ());
55a2c322	243	mv_num = 0;
55a2c322 VM	244	/* Collect moves. */
55a2c322 VM	245	coalesced_moves = 0;
11cd3bed	246	FOR_EACH_BB_FN (bb, cfun)
55a2c322 VM	247	{
	248	FOR_BB_INSNS_SAFE (bb, insn, next)
	249	if (INSN_P (insn)
	250	&& (set = single_set (insn)) != NULL_RTX
	251	&& REG_P (SET_DEST (set)) && REG_P (SET_SRC (set))
	252	&& (sregno = REGNO (SET_SRC (set))) >= FIRST_PSEUDO_REGISTER
	253	&& (dregno = REGNO (SET_DEST (set))) >= FIRST_PSEUDO_REGISTER
	254	&& mem_move_p (sregno, dregno)
72ea0d47	255	&& coalescable_pseudo_p (sregno) && coalescable_pseudo_p (dregno)
55a2c322 VM	256	&& ! side_effects_p (set)
	257	&& !(lra_intersected_live_ranges_p
	258	(lra_reg_info[sregno].live_ranges,
	259	lra_reg_info[dregno].live_ranges)))
	260	sorted_moves[mv_num++] = insn;
	261	}
55a2c322 VM	262	qsort (sorted_moves, mv_num, sizeof (rtx), move_freq_compare_func);
	263	/* Coalesced copies, most frequently executed first. */
	264	bitmap_initialize (&coalesced_pseudos_bitmap, &reg_obstack);
	265	bitmap_initialize (&involved_insns_bitmap, &reg_obstack);
	266	for (i = 0; i < mv_num; i++)
	267	{
	268	mv = sorted_moves[i];
	269	set = single_set (mv);
	270	lra_assert (set != NULL && REG_P (SET_SRC (set))
	271	&& REG_P (SET_DEST (set)));
	272	sregno = REGNO (SET_SRC (set));
	273	dregno = REGNO (SET_DEST (set));
	274	if (first_coalesced_pseudo[sregno] == first_coalesced_pseudo[dregno])
	275	{
	276	coalesced_moves++;
	277	if (lra_dump_file != NULL)
	278	fprintf
	279	(lra_dump_file, " Coalescing move %i:r%d-r%d (freq=%d)\n",
	280	INSN_UID (mv), sregno, dregno,
fef37404	281	REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv)));
55a2c322 VM	282	/* We updated involved_insns_bitmap when doing the merge. */
	283	}
	284	else if (!(lra_intersected_live_ranges_p
	285	(lra_reg_info[first_coalesced_pseudo[sregno]].live_ranges,
	286	lra_reg_info[first_coalesced_pseudo[dregno]].live_ranges)))
	287	{
	288	coalesced_moves++;
	289	if (lra_dump_file != NULL)
	290	fprintf
	291	(lra_dump_file,
	292	" Coalescing move %i:r%d(%d)-r%d(%d) (freq=%d)\n",
	293	INSN_UID (mv), sregno, ORIGINAL_REGNO (SET_SRC (set)),
	294	dregno, ORIGINAL_REGNO (SET_DEST (set)),
fef37404	295	REG_FREQ_FROM_BB (BLOCK_FOR_INSN (mv)));
55a2c322 VM	296	bitmap_ior_into (&involved_insns_bitmap,
	297	&lra_reg_info[sregno].insn_bitmap);
	298	bitmap_ior_into (&involved_insns_bitmap,
	299	&lra_reg_info[dregno].insn_bitmap);
	300	merge_pseudos (sregno, dregno);
	301	}
	302	}
	303	bitmap_initialize (&used_pseudos_bitmap, &reg_obstack);
11cd3bed	304	FOR_EACH_BB_FN (bb, cfun)
55a2c322 VM	305	{
	306	update_live_info (df_get_live_in (bb));
	307	update_live_info (df_get_live_out (bb));
	308	FOR_BB_INSNS_SAFE (bb, insn, next)
	309	if (INSN_P (insn)
	310	&& bitmap_bit_p (&involved_insns_bitmap, INSN_UID (insn)))
	311	{
cfa434f6	312	if (! substitute_within_insn (insn))
55a2c322 VM	313	continue;
	314	lra_update_insn_regno_info (insn);
	315	if ((set = single_set (insn)) != NULL_RTX && set_noop_p (set))
	316	{
	317	/* Coalesced move. */
	318	if (lra_dump_file != NULL)
	319	fprintf (lra_dump_file, " Removing move %i (freq=%d)\n",
fef37404 VM	320	INSN_UID (insn),
fef37404 VM	321	REG_FREQ_FROM_BB (BLOCK_FOR_INSN (insn)));
55a2c322 VM	322	lra_set_insn_deleted (insn);
	323	}
	324	}
	325	}
c9846a8c VM	326	/* If we have situation after inheritance pass:
c9846a8c VM	327
35b707ff	328	r1 <- p1 insn originally setting p1
c9846a8c VM	329	i1 <- r1 setting inheritance i1 from reload r1
	330	...
	331	... <- ... p2 ... dead p2
	332	..
	333	p1 <- i1
	334	r2 <- i1
	335	...<- ... r2 ...
	336
	337	And we are coalescing p1 and p2 using p1. In this case i1 and p1
	338	should have different values, otherwise they can get the same
	339	hard reg and this is wrong for insn using p2 before coalescing.
35b707ff VM	340	The situation even can be more complicated when new reload
	341	pseudos occur after the inheriatnce. So invalidate the result
	342	pseudos. */
	343	for (i = 0; i < max_regno; i++)
	344	if (first_coalesced_pseudo[i] == i
	345	&& first_coalesced_pseudo[i] != next_coalesced_pseudo[i])
c9846a8c	346	{
35b707ff	347	lra_set_regno_unique_value (i);
c9846a8c VM	348	if (lra_dump_file != NULL)
c9846a8c VM	349	fprintf (lra_dump_file,
35b707ff	350	" Make unique value for coalescing result r%d\n", i);
c9846a8c	351	}
55a2c322 VM	352	bitmap_clear (&used_pseudos_bitmap);
	353	bitmap_clear (&involved_insns_bitmap);
	354	bitmap_clear (&coalesced_pseudos_bitmap);
	355	if (lra_dump_file != NULL && coalesced_moves != 0)
	356	fprintf (lra_dump_file, "Coalesced Moves = %d\n", coalesced_moves);
	357	free (sorted_moves);
	358	free (next_coalesced_pseudo);
	359	free (first_coalesced_pseudo);
	360	timevar_pop (TV_LRA_COALESCE);
	361	return coalesced_moves != 0;
	362	}