combine.c (try_combine): Don't ignore result of overlap checking loop.

	* combine.c (try_combine): Don't ignore result of overlap checking
	loop.  Combine overlap & asm check into single loop.

Co-Authored-By: Nicolai Stange <nicstange@gmail.com>

From-SVN: r244361

gcc/ChangeLog

+2017-01-12  Nathan Sidwell  <nathan@acm.org>
+	    Nicolai Stange  <nicstange@gmail.com>
+
+	* combine.c (try_combine): Don't ignore result of overlap checking
+	loop.  Combine overlap & asm check into single loop.
+
 2017-01-12  Richard Biener  <rguenther@suse.de>
 
 	* tree-pretty-print.c (dump_generic_node): Provide -gimple

gcc/combine.c

@@ -2785,22 +2785,24 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
 	 (Besides, reload can't handle output reloads for this.)
 
 	 The problem can also happen if the dest of I3 is a memory ref,
-	 if another dest in I2 is an indirect memory ref.  */
-      for (i = 0; i < XVECLEN (p2, 0); i++)
-	if ((GET_CODE (XVECEXP (p2, 0, i)) == SET
-	     || GET_CODE (XVECEXP (p2, 0, i)) == CLOBBER)
-	    && reg_overlap_mentioned_p (SET_DEST (PATTERN (i3)),
-					SET_DEST (XVECEXP (p2, 0, i))))
-	  break;
+	 if another dest in I2 is an indirect memory ref.
 
-      /* Make sure this PARALLEL is not an asm.  We do not allow combining
+	 Neither can this PARALLEL be an asm.  We do not allow combining
 	 that usually (see can_combine_p), so do not here either.  */
-      for (i = 0; i < XVECLEN (p2, 0); i++)
-	if (GET_CODE (XVECEXP (p2, 0, i)) == SET
-	    && GET_CODE (SET_SRC (XVECEXP (p2, 0, i))) == ASM_OPERANDS)
-	  break;
+      bool ok = true;
+      for (i = 0; ok && i < XVECLEN (p2, 0); i++)
+	{
+	  if ((GET_CODE (XVECEXP (p2, 0, i)) == SET
+	       || GET_CODE (XVECEXP (p2, 0, i)) == CLOBBER)
+	      && reg_overlap_mentioned_p (SET_DEST (PATTERN (i3)),
+					  SET_DEST (XVECEXP (p2, 0, i))))
+	    ok = false;
+	  else if (GET_CODE (XVECEXP (p2, 0, i)) == SET
+		   && GET_CODE (SET_SRC (XVECEXP (p2, 0, i))) == ASM_OPERANDS)
+	    ok = false;
+	}
 
-      if (i == XVECLEN (p2, 0))
+      if (ok)
 	for (i = 0; i < XVECLEN (p2, 0); i++)
 	  if (GET_CODE (XVECEXP (p2, 0, i)) == SET
 	      && SET_DEST (XVECEXP (p2, 0, i)) == SET_SRC (PATTERN (i3)))