Re: [PATCH, 5.1, rs6000] Fix PR65787

[Bill Schmidt <wschmidt@linux.vnet.ibm.com>]

Hi,

On Fri, 2015-04-17 at 10:02 -0500, Bill Schmidt wrote:
> On Fri, 2015-04-17 at 16:49 +0200, Jakub Jelinek wrote:
> > You have actually mailed the original patch again, not the revised one.
> 
> > That said, PARALLEL seems to be already handled by rtx_is_swappable_p,
> > so if it isn't handled correctly, perhaps there is a bug in that function.
> > 

Quite right.  I've fixed this as you suggested in the attached patch.
Bootstrapped and tested on powerpc64le-linux-gnu with no regressions.
Is this version ok?

Sorry for apparently not knowing my own code as well as I should... :/

Thanks,
Bill


2015-04-17  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR target/65787
	* config/rs6000/rs6000.c (rtx_is_swappable_p): Remove previous
	fix; ensure that a subsequent SH_NONE operand does not overwrite
	an existing *special value.


Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c	(revision 222182)
+++ gcc/config/rs6000/rs6000.c	(working copy)
@@ -34204,17 +34204,6 @@ rtx_is_swappable_p (rtx op, unsigned int *special)
       else
 	return 0;
 
-    case PARALLEL:
-      /* A vec_extract operation may be wrapped in a PARALLEL with a
-	 clobber, so account for that possibility.  */
-      if (XVECLEN (op, 0) != 2)
-	return 0;
-
-      if (GET_CODE (XVECEXP (op, 0, 1)) != CLOBBER)
-	return 0;
-
-      return rtx_is_swappable_p (XVECEXP (op, 0, 0), special);
-
     case UNSPEC:
       {
 	/* Various operations are unsafe for this optimization, at least
@@ -34308,6 +34297,8 @@ rtx_is_swappable_p (rtx op, unsigned int *special)
 	{
 	  unsigned int special_op = SH_NONE;
 	  ok &= rtx_is_swappable_p (XVECEXP (op, i, j), &special_op);
+	  if (special_op == SH_NONE)
+	    continue;
 	  /* Ensure we never have two kinds of special handling
 	     for the same insn.  */
 	  if (*special != SH_NONE && special_op != SH_NONE