re PR middle-end/28964 (partition_stack_vars uses unstable sort)

2006-09-22  Richard Guenther  <rguenther@suse.de>

	PR middle-end/28964
	* cfgexpand.c (stack_var_size_cmp): Use DECL_UID to make
	sort of stack variables stable.

From-SVN: r117146

gcc/ChangeLog

+2006-09-22  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/28964
+	* cfgexpand.c (stack_var_size_cmp): Use DECL_UID to make
+	sort of stack variables stable.
+
 2006-09-22  Peter Bergner <bergner@vnet.ibm.com>
 
 	PR middle-end/28690

gcc/cfgexpand.c

@@ -350,11 +350,19 @@ stack_var_size_cmp (const void *a, const void *b)
 {
   HOST_WIDE_INT sa = stack_vars[*(const size_t *)a].size;
   HOST_WIDE_INT sb = stack_vars[*(const size_t *)b].size;
+  unsigned int uida = DECL_UID (stack_vars[*(const size_t *)a].decl);
+  unsigned int uidb = DECL_UID (stack_vars[*(const size_t *)b].decl);
 
   if (sa < sb)
     return -1;
   if (sa > sb)
     return 1;
+  /* For stack variables of the same size use the uid of the decl
+     to make the sort stable.  */
+  if (uida < uidb)
+    return -1;
+  if (uida > uidb)
+    return 1;
   return 0;
 }