diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ccb7019fa41..f01b9fe11ae 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+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
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 600655d1d2c..5c3b6971e34 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+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
diff --git a/gcc/testsuite/g++.dg/torture/20100825.C b/gcc/testsuite/g++.dg/torture/20100825.C
new file mode 100644
index 00000000000..460c1b60875
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/20100825.C
@@ -0,0 +1,15 @@
+// { 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 ();
+}
diff --git a/gcc/tree-ssa-copyrename.c b/gcc/tree-ssa-copyrename.c
index 41d43a6179c..abee6b9407f 100644
--- a/gcc/tree-ssa-copyrename.c
+++ b/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;
     }