blob: 1088ceeb0f9f49d5219d70942a2a252fb7fbd880 [file] [log] [blame]
// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
//
// Check that optimizer correctly handles (x << y) & MASK_32 pattern on 32-bit
// platforms: given the pattern
//
// v1 <- UnboxedIntConverter([tr] mint->uint32, v0)
// v2 <- UnboxedIntConverter(uint32->mint, v1)
//
// optimizer must *not* replace v2 with v0 because the first conversion is
// truncating and is erasing the high part of the mint value.
//
// VMOptions=--optimization-counter-threshold=5 --no-background-compilation
// @dart = 2.9
import "package:expect/expect.dart";
const _MASK_32 = 0xffffffff;
int _rotl32(int val, int shift) {
final mod_shift = shift & 31;
return ((val << mod_shift) & _MASK_32) |
((val & _MASK_32) >> (32 - mod_shift));
}
rot8(v) => _rotl32(v, 8);
main() {
// Note: value is selected in such a way that (value << 8) is not a smi - this
// triggers emission of BinaryMintOp instructions for shifts.
const value = 0xF0F00000;
const rotated = 0xF00000F0;
Expect.equals(rotated, rot8(value));
for (var i = 0; i < 10; i++) {
Expect.equals(rotated, rot8(value));
}
}