Files
sdk/tests/language/bit_shift_test.dart
T
Alexander Markov c8860b4ca2 Remove all uses of --limit-ints-to-64-bits VM option
VM option --limit-ints-to-64-bits was enabled by default a while ago,
and now we're preparing to remove it from Dart VM.

This CL removes all uses of this option in preparation for this cleanup.

Issue: https://github.com/dart-lang/sdk/issues/33306
Change-Id: I8f33cf4ca8ce7ef9a171a982346e43dd8cb722a9
Reviewed-on: https://dart-review.googlesource.com/57960
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2018-06-01 19:32:24 +00:00

64 lines
1.6 KiB
Dart

// Copyright (c) 2012, 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.
// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
import "package:expect/expect.dart";
// Note: in Dart 2 mode all integers are 64-bit already.
// Still, it is harmless to apply _uint64Mask because (1 << 64) is 0 (all bits
// are shifted out), so _uint64Mask is -1 (its bit pattern is 0xffffffffffffffff).
const _uint64Mask = (1 << 64) - 1;
constants() {
Expect.equals(0, 499 >> 33);
Expect.equals(0, (499 << 33) & 0xFFFFFFFF);
Expect.equals(0, (499 << 32) >> 65);
Expect.equals(0, ((499 << 32) << 65) & _uint64Mask);
}
foo(i) {
if (i != 0) {
y--;
foo(i - 1);
y++;
}
}
var y;
// id returns [x] in a way that should be difficult to predict statically.
id(x) {
y = x;
foo(10);
return y;
}
interceptors() {
Expect.equals(0, id(499) >> 33);
Expect.equals(0, (id(499) << 33) & 0xFFFFFFFF);
Expect.equals(0, id(499 << 32) >> 65);
Expect.equals(0, (id(499 << 32) << 65) & _uint64Mask);
}
speculative() {
var a = id(499);
var b = id(499 << 32);
for (int i = 0; i < 1; i++) {
Expect.equals(0, a >> 33);
Expect.equals(0, (a << 33) & 0xFFFFFFFF);
Expect.equals(0, b >> 65);
Expect.equals(0, (b << 65) & _uint64Mask);
}
}
// JavaScript shifts by the amount modulo 32. That is x << y is equivalent to
// x << (y & 0x1F). Dart does not.
main() {
for (var i = 0; i < 10; ++i) {
constants();
interceptors();
speculative();
}
}