re PR rtl-optimization/12799 (faulty mov->add change clobbers the CC register)

	PR optimization/12799
	* postreload.c (reload_cse_move2add): Generate the add2
	patterns manually.

From-SVN: r73195

gcc/ChangeLog

 2003-11-02  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	PR optimization/12799
+	* postreload.c (reload_cse_move2add): Generate the add2
+	patterns manually.
+
+2003-11-02  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	* config/sparc/sparc.c (function_arg_partial_nregs) [TARGET_ARCH64]:
 	Return 0 for all complex modes whose size is lesser or equal to
 	a word.  Add a ??? comment for the condition used with 16-byte

gcc/postreload.c

@@ -1199,14 +1199,12 @@ reload_cse_move2add (rtx first)
 		  else if (rtx_cost (new_src, PLUS) < rtx_cost (src, SET)
 			   && have_add2_insn (reg, new_src))
 		    {
-		      rtx newpat = gen_add2_insn (reg, new_src);
-		      if (INSN_P (newpat) && NEXT_INSN (newpat) == NULL_RTX)
-			newpat = PATTERN (newpat);
-		      /* If it was the first insn of a sequence or
-			 some other emitted insn, validate_change will
-			 reject it.  */
-		      validate_change (insn, &PATTERN (insn),
-				       newpat, 0);
+		      rtx newpat = gen_rtx_SET (VOIDmode,
+						reg,
+						gen_rtx_PLUS (GET_MODE (reg),
+						 	      reg,
+						 	      new_src));
+		      validate_change (insn, &PATTERN (insn), newpat, 0);
 		    }
 		  else
 		    {
@@ -1288,10 +1286,11 @@ reload_cse_move2add (rtx first)
 				< COSTS_N_INSNS (1) + rtx_cost (src3, SET))
 			       && have_add2_insn (reg, new_src))
 			{
-			  rtx newpat = gen_add2_insn (reg, new_src);
-			  if (INSN_P (newpat)
-			      && NEXT_INSN (newpat) == NULL_RTX)
-			    newpat = PATTERN (newpat);
+			  rtx newpat = gen_rtx_SET (VOIDmode,
+						    reg,
+						    gen_rtx_PLUS (GET_MODE (reg),
+						 		  reg,
+								  new_src));
 			  success
 			    = validate_change (next, &PATTERN (next),
 					       newpat, 0);

gcc/testsuite/ChangeLog

 2003-11-02  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	* gcc.dg/20031102-1.c: New test.
+
+2003-11-02  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	* gcc.dg/complex-1.c: New test.
 
 2003-11-01  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>

gcc/testsuite/gcc.dg/20031102-1.c

+/* PR optimization/12799 */
+/* Origin: Pratap Subrahmanyam <pratap@vmware.com> */
+
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-options "-O2 -march=i686" { target i686-*-* } } */
+
+/* Verify that reload_cse_move2add doesn't add unexpected CLOBBERs. */
+
+extern void abort(void);
+
+int loo = 1;
+
+__inline__ char InlineFunc(void)
+{
+  return __builtin_expect(!!(loo == 1), 1);
+}
+
+int FooBar(void)
+{
+  int i;
+  int var1 = InlineFunc() ? 2046 : 1023;
+  int var2 = InlineFunc() ? 512 : 1024;
+
+  for (i = 0; i < var1; i++)
+    ;
+
+  if (InlineFunc() && var2 != 512)
+    abort();
+
+  return 0;
+}
+
+int main(void)
+{
+  return FooBar();
+}