fix ifcvt rtl sharing

[Alan Modra]

This patch cures PR 12067, a combine problem caused by shared rtl.  The
noce_try_cmove change is the specific fix for the bug report, the other
changes are by inspection for similar places that could run into rtl
sharing problems.

	PR optimization/12067
	* ifcvt.c (noce_try_cmove): Unshare cond rtl.
	(noce_try_addcc): Likewise.
	(noce_try_cmove_arith): Likewise.
	(noce_get_alt_condition): Likewise.

Bootstrapped i686-linux, regression test in progress.  OK for head/3.3?

Index: gcc/ifcvt.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ifcvt.c,v
retrieving revision 1.124
diff -u -p -r1.124 ifcvt.c
--- gcc/ifcvt.c	26 Jul 2003 18:38:42 -0000	1.124
+++ gcc/ifcvt.c	27 Aug 2003 01:59:57 -0000
@@ -900,7 +900,8 @@ noce_try_addcc (struct noce_if_info *if_
 	{
 	  start_sequence ();
 	  target = emit_conditional_add (if_info->x, code,
-					 XEXP (cond, 0), XEXP (cond, 1),
+					 copy_rtx (XEXP (cond, 0)),
+					 copy_rtx (XEXP (cond, 1)),
 					 VOIDmode,
 					 if_info->b, XEXP (if_info->a, 1),
 					 GET_MODE (if_info->x),
@@ -1089,8 +1090,8 @@ noce_try_cmove (struct noce_if_info *if_
 
       code = GET_CODE (if_info->cond);
       target = noce_emit_cmove (if_info, if_info->x, code,
-				XEXP (if_info->cond, 0),
-				XEXP (if_info->cond, 1),
+				copy_rtx (XEXP (if_info->cond, 0)),
+				copy_rtx (XEXP (if_info->cond, 1)),
 				if_info->a, if_info->b);
 
       if (target)
@@ -1232,8 +1233,9 @@ noce_try_cmove_arith (struct noce_if_inf
 	goto end_seq_and_fail;
     }
 
-  target = noce_emit_cmove (if_info, x, code, XEXP (if_info->cond, 0),
-			    XEXP (if_info->cond, 1), a, b);
+  target = noce_emit_cmove (if_info, x, code,
+			    copy_rtx (XEXP (if_info->cond, 0)),
+			    copy_rtx (XEXP (if_info->cond, 1)), a, b);
 
   if (! target)
     goto end_seq_and_fail;
@@ -1390,7 +1392,8 @@ noce_get_alt_condition (struct noce_if_i
 	  || op_a != XEXP (if_info->cond, 0)
 	  || op_b != XEXP (if_info->cond, 1))
 	{
-	  cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
+	  cond = gen_rtx_fmt_ee (code, GET_MODE (cond),
+				 copy_rtx (op_a), copy_rtx (op_b));
 	  *earliest = if_info->cond_earliest;
 	  return cond;
 	}

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre