fold-const.c (fold, [...]): Elide conversion between cv-qualified versions of types.

        * fold-const.c (fold, case COND_EXPR): Elide conversion between
        cv-qualified versions of types.

From-SVN: r34416

gcc/ChangeLog

+2000-06-05  Jason Merrill  <jason@casey.soma.redhat.com>
+
+	* fold-const.c (fold, case COND_EXPR): Elide conversion between
+	cv-qualified versions of types.
+
 Mon Jun  5 14:06:18 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
 	* config/sparc/sparc.c (short_branch): Correct error in range

gcc/fold-const.c

@@ -6903,6 +6903,10 @@ fold (expr)
 	      tree comp_op1 = TREE_OPERAND (arg0, 1);
 	      tree comp_type = TREE_TYPE (comp_op0);
 
+	      /* Avoid adding NOP_EXPRs in case this is an lvalue.  */
+	      if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
+		comp_type = type;
+
 	      switch (comp_code)
 		{
 		case EQ_EXPR: