re PR tree-optimization/46806 (-O3 implies 0 <= 8 <= 7)

2010-12-06  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/46806
	* tree-ssa-copyrename.c (copy_rename_partition_coalesce): Do not
	coalesce different types.

	* g++.dg/torture/20100825.C: New testcase.

From-SVN: r167490

gcc/ChangeLog

 2010-12-06  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/46806
+	* tree-ssa-copyrename.c (copy_rename_partition_coalesce): Do not
+	coalesce different types.
+
+2010-12-06  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/46785
 	* tree-vect-loop.c (vect_is_simple_reduction_1): Also allow
 	call statements as operand definition.

gcc/testsuite/ChangeLog

 2010-12-06  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/46806
+	* g++.dg/torture/20100825.C: New testcase.
+
+2010-12-06  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/46785
 	* gcc.dg/vect/fast-math-vect-reduc-9.c: New testcase.
 

gcc/testsuite/g++.dg/torture/20100825.C

+// { dg-do run }
+
+typedef enum { zero = 0, one = 1, two = 2, ENUM_MAX = 3 } my_enum;
+my_enum e;
+extern "C" void abort (void);
+int __attribute__((noinline)) foo() { return 10; }
+int main()
+{
+  int r;
+  r = foo();
+  if ((r < 0) || (r >= ENUM_MAX))
+    return 0;
+  e = (my_enum)r;
+  abort ();
+}

gcc/tree-ssa-copyrename.c

@@ -226,11 +226,11 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
       ign2 = false;
     }
 
-  /* Don't coalesce if the two variables aren't type compatible.  */
-  if (!types_compatible_p (TREE_TYPE (root1), TREE_TYPE (root2)))
+  /* Don't coalesce if the two variables are not of the same type.  */
+  if (TREE_TYPE (root1) != TREE_TYPE (root2))
     {
       if (debug)
-	fprintf (debug, " : Incompatible types.  No coalesce.\n");
+	fprintf (debug, " : Different types.  No coalesce.\n");
       return false;
     }