if (operand_equal_p (arg0, arg1, 0))
return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0));
- /* ~X & X is always zero. */
- if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ /* ~X & X, (X == 0) & X, and !X & X are always zero. */
+ if ((TREE_CODE (arg0) == BIT_NOT_EXPR
+ || TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ || (TREE_CODE (arg0) == EQ_EXPR
+ && integer_zerop (TREE_OPERAND (arg0, 1))))
&& operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
return omit_one_operand_loc (loc, type, integer_zero_node, arg1);
- /* X & ~X is always zero. */
- if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ /* X & ~X , X & (X == 0), and X & !X are always zero. */
+ if ((TREE_CODE (arg1) == BIT_NOT_EXPR
+ || TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ || (TREE_CODE (arg1) == EQ_EXPR
+ && integer_zerop (TREE_OPERAND (arg1, 1))))
&& operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
return omit_one_operand_loc (loc, type, integer_zero_node, arg0);
build_int_cst (TREE_TYPE (tem), 1)),
build_int_cst (TREE_TYPE (tem), 0));
}
+ /* Fold !X & 1 as X == 0. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && integer_onep (arg1))
+ {
+ tem = TREE_OPERAND (arg0, 0);
+ return fold_build2_loc (loc, EQ_EXPR, type, tem,
+ build_int_cst (TREE_TYPE (tem), 0));
+ }
/* Fold (X ^ Y) & Y as ~X & Y. */
if (TREE_CODE (arg0) == BIT_XOR_EXPR