diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/range-op.cc | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/gcc/range-op.cc b/gcc/range-op.cc index 072ebd3..fc930f4 100644 --- a/gcc/range-op.cc +++ b/gcc/range-op.cc @@ -2951,6 +2951,15 @@ operator_bitwise_and::op1_range (irange &r, tree type, } if (r.undefined_p ()) set_nonzero_range_from_mask (r, type, lhs); + + // For 0 = op1 & MASK, op1 is ~MASK. + if (lhs.zero_p () && op2.singleton_p ()) + { + wide_int nz = wi::bit_not (op2.get_nonzero_bits ()); + int_range<2> tmp (type); + tmp.set_nonzero_bits (nz); + r.intersect (tmp); + } return true; } @@ -4612,6 +4621,15 @@ range_op_bitwise_and_tests () op_bitwise_and.op1_range (res, integer_type_node, i1, i2); ASSERT_TRUE (res == int_range<1> (integer_type_node)); + // For 0 = x & MASK, x is ~MASK. + { + int_range<2> zero (integer_zero_node, integer_zero_node); + int_range<2> mask = int_range<2> (INT (7), INT (7)); + op_bitwise_and.op1_range (res, integer_type_node, zero, mask); + wide_int inv = wi::shwi (~7U, TYPE_PRECISION (integer_type_node)); + ASSERT_TRUE (res.get_nonzero_bits () == inv); + } + // (NONZERO | X) is nonzero. i1.set_nonzero (integer_type_node); i2.set_varying (integer_type_node); |