tree-ssa-loop-niter.c (simplify_replace_tree): Do not replace constants.

2010-06-09  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-loop-niter.c (simplify_replace_tree): Do not
	replace constants.

From-SVN: r160467

gcc/ChangeLog

+2010-06-09  Richard Guenther  <rguenther@suse.de>
+
+	* tree-ssa-loop-niter.c (simplify_replace_tree): Do not
+	replace constants.
+
 2010-06-09  Kai Tietz  <kai.tietz@onevision.com>
 
 	* c-objc-common.c (c_tree_printer): Pre-intialize t by NULL_TREE.

gcc/tree-ssa-loop-niter.c

@@ -1374,6 +1374,10 @@ simplify_replace_tree (tree expr, tree old, tree new_tree)
   if (!expr)
     return NULL_TREE;
 
+  /* Do not bother to replace constants.  */
+  if (CONSTANT_CLASS_P (old))
+    return expr;
+
   if (expr == old
       || operand_equal_p (expr, old, 0))
     return unshare_expr (new_tree);