fold-const.c (fold_unary): Optimize away a VIEW_CONVERT_EXPR to the same type as it's operand.

	* fold-const.c (fold_unary) <VIEW_CONVERT_EXPR>: Optimize away a
	VIEW_CONVERT_EXPR to the same type as it's operand.

From-SVN: r120945

gcc/ChangeLog

+2007-01-18  Roger Sayle  <roger@eyesopen.com>
+
+	* fold-const.c (fold_unary) <VIEW_CONVERT_EXPR>: Optimize away a
+	VIEW_CONVERT_EXPR to the same type as it's operand.
+
 2007-01-18  David Edelsohn  <edelsohn@gnu.org>
 
 	* config/rs6000/darwin-ldouble.c: Only build _SOFT_FLOAT if

gcc/fold-const.c

@@ -7573,6 +7573,8 @@ fold_unary (enum tree_code code, tree type, tree op0)
       return tem ? tem : NULL_TREE;
 
     case VIEW_CONVERT_EXPR:
+      if (TREE_TYPE (op0) == type)
+	return op0;
       if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
 	return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
       return fold_view_convert_expr (type, op0);