* combine.c (combine_validate_cost): New parameter NEWOTHERPAT.

	(try_combine): Move potential calls to undo_all() so they happen
	before we commit to using the combined insns.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@126142 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 37 insertions, 29 deletions

diff --git a/gcc/combine.c b/gcc/combine.c
index fece7e02614..5cf65bae192 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -741,14 +741,17 @@ do_SUBST_MODE (rtx *into, enum machine_mode newval)
 #define SUBST_MODE(INTO, NEWVAL)  do_SUBST_MODE(&(INTO), (NEWVAL))
 
 /* Subroutine of try_combine.  Determine whether the combine replacement
-   patterns NEWPAT and NEWI2PAT are cheaper according to insn_rtx_cost
-   that the original instruction sequence I1, I2 and I3.  Note that I1
-   and/or NEWI2PAT may be NULL_RTX.  This function returns false, if the
-   costs of all instructions can be estimated, and the replacements are
-   more expensive than the original sequence.  */
+   patterns NEWPAT, NEWI2PAT and NEWOTHERPAT are cheaper according to
+   insn_rtx_cost that the original instruction sequence I1, I2, I3 and
+   undobuf.other_insn.  Note that I1 and/or NEWI2PAT may be NULL_RTX. 
+   NEWOTHERPAT and undobuf.other_insn may also both be NULL_RTX.  This
+   function returns false, if the costs of all instructions can be
+   estimated, and the replacements are more expensive than the original
+   sequence.  */
 
 static bool
-combine_validate_cost (rtx i1, rtx i2, rtx i3, rtx newpat, rtx newi2pat)
+combine_validate_cost (rtx i1, rtx i2, rtx i3, rtx newpat, rtx newi2pat,
+		       rtx newotherpat)
 {
   int i1_cost, i2_cost, i3_cost;
   int new_i2_cost, new_i3_cost;
@@ -789,7 +792,7 @@ combine_validate_cost (rtx i1, rtx i2, rtx i3, rtx newpat, rtx newi2pat)
       int old_other_cost, new_other_cost;
 
       old_other_cost = INSN_COST (undobuf.other_insn);
-      new_other_cost = insn_rtx_cost (PATTERN (undobuf.other_insn));
+      new_other_cost = insn_rtx_cost (newotherpat);
       if (old_other_cost > 0 && new_other_cost > 0)
 	{
 	  old_cost += old_other_cost;
@@ -2159,6 +2162,8 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
   int maxreg;
   rtx temp;
   rtx link;
+  rtx other_pat = 0;
+  rtx new_other_notes;
   int i;
 
   /* Exit early if one of the insns involved can't be used for
@@ -3285,12 +3290,9 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
   /* If we had to change another insn, make sure it is valid also.  */
   if (undobuf.other_insn)
     {
-      rtx other_pat = PATTERN (undobuf.other_insn);
-      rtx new_other_notes;
-      rtx note, next;
-
       CLEAR_HARD_REG_SET (newpat_used_regs);
 
+      other_pat = PATTERN (undobuf.other_insn);
       other_code_number = recog_for_combine (&other_pat, undobuf.other_insn,
 					     &new_other_notes);
 
@@ -3299,24 +3301,8 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
 	  undo_all ();
 	  return 0;
 	}
-
-      PATTERN (undobuf.other_insn) = other_pat;
-
-      /* If any of the notes in OTHER_INSN were REG_UNUSED, ensure that they
-	 are still valid.  Then add any non-duplicate notes added by
-	 recog_for_combine.  */
-      for (note = REG_NOTES (undobuf.other_insn); note; note = next)
-	{
-	  next = XEXP (note, 1);
-
-	  if (REG_NOTE_KIND (note) == REG_UNUSED
-	      && ! reg_set_p (XEXP (note, 0), PATTERN (undobuf.other_insn)))
-	    remove_note (undobuf.other_insn, note);
-	}
-
-      distribute_notes (new_other_notes, undobuf.other_insn,
-			undobuf.other_insn, NULL_RTX, NULL_RTX, NULL_RTX);
     }
+
 #ifdef HAVE_cc0
   /* If I2 is the CC0 setter and I3 is the CC0 user then check whether
      they are adjacent to each other or not.  */
@@ -3333,7 +3319,7 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
 
   /* Only allow this combination if insn_rtx_costs reports that the
      replacement instructions are cheaper than the originals.  */
-  if (!combine_validate_cost (i1, i2, i3, newpat, newi2pat))
+  if (!combine_validate_cost (i1, i2, i3, newpat, newi2pat, other_pat))
     {
       undo_all ();
       return 0;
@@ -3342,6 +3328,28 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
   /* We now know that we can do this combination.  Merge the insns and
      update the status of registers and LOG_LINKS.  */
 
+  if (undobuf.other_insn)
+    {
+      rtx note, next;
+
+      PATTERN (undobuf.other_insn) = other_pat;
+
+      /* If any of the notes in OTHER_INSN were REG_UNUSED, ensure that they
+	 are still valid.  Then add any non-duplicate notes added by
+	 recog_for_combine.  */
+      for (note = REG_NOTES (undobuf.other_insn); note; note = next)
+	{
+	  next = XEXP (note, 1);
+
+	  if (REG_NOTE_KIND (note) == REG_UNUSED
+	      && ! reg_set_p (XEXP (note, 0), PATTERN (undobuf.other_insn)))
+	    remove_note (undobuf.other_insn, note);
+	}
+
+      distribute_notes (new_other_notes, undobuf.other_insn,
+			undobuf.other_insn, NULL_RTX, NULL_RTX, NULL_RTX);
+    }
+
   if (swap_i2i3)
     {
       rtx insn;