fold-const.c (fold_single_bit_test): Fix overflow test.

2013-08-30  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_single_bit_test): Fix overflow test.

From-SVN: r202103

gcc/ChangeLog

+2013-08-30  Richard Biener  <rguenther@suse.de>
+
+	* fold-const.c (fold_single_bit_test): Fix overflow test.
+
 2013-08-30  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* function.c (assign_parm_setup_reg): For a parameter passed by pointer

gcc/fold-const.c

@@ -6634,10 +6634,10 @@ fold_single_bit_test (location_t loc, enum tree_code code,
 	 not overflow, adjust BITNUM and INNER.  */
       if (TREE_CODE (inner) == RSHIFT_EXPR
 	  && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
-	  && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
+	  && host_integerp (TREE_OPERAND (inner, 1), 1)
 	  && bitnum < TYPE_PRECISION (type)
-	  && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
-				   bitnum - TYPE_PRECISION (type)))
+	  && (TREE_INT_CST_LOW (TREE_OPERAND (inner, 1))
+	      < (unsigned) (TYPE_PRECISION (type) - bitnum)))
 	{
 	  bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
 	  inner = TREE_OPERAND (inner, 0);