02d999abad
This fixes the signature of "Math.abs" from "(signed) -> signed" to "(signed) -> unsigned" and hence fixes cases where the absolute value would overflow the range of signed 32-bit values. This is in sync with spec erratas (and ECMAScript semantics). Note that this also switches the underlying implementation of the above absolute value function to a branch-free version. R=clemensh@chromium.org TEST=mjsunit/regress/regress-6838-3 BUG=v8:6838 Change-Id: Ib13b7ecd336ae386cbde7c574e727bf52f841e00 Reviewed-on: https://chromium-review.googlesource.com/684181 Commit-Queue: Michael Starzinger <mstarzinger@chromium.org> Reviewed-by: Clemens Hammacher <clemensh@chromium.org> Cr-Commit-Position: refs/heads/master@{#48169}
40 lines
988 B
JavaScript
40 lines
988 B
JavaScript
// Copyright 2017 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Flags: --allow-natives-syntax
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(function TestMathAbsReturningUnsigned() {
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function Module(stdlib) {
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"use asm";
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var abs=stdlib.Math.abs;
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function f(a, b) {
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a = a | 0;
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b = b | 0;
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return (abs(a >> 0) == (b >>> 0)) | 0;
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}
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return f;
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}
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var f = Module(this);
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assertEquals(0, f(1, 2));
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assertEquals(1, f(23, 23));
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assertEquals(1, f(-42, 42));
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assertEquals(1, f(-0x7fffffff, 0x7fffffff));
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assertEquals(1, f(-0x80000000, 0x80000000));
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assertTrue(%IsAsmWasmCode(Module));
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})();
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(function TestMathAbsOverflowSignedValue() {
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function Module(stdlib) {
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"use asm";
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var abs=stdlib.Math.abs;
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function f() {
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return (abs(-0x80000000) > 0) | 0;
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}
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return f;
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}
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var f = Module(this);
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assertEquals(1, f());
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assertTrue(%IsAsmWasmCode(Module));
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})();
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