v8/test/mjsunit/compiler/number-subtract.js
Ross McIlroy 31a3cfbc10 [Test] Add PrepareForOptimization to mjsunit/compiler
BUG=v8:8801

Change-Id: I9d9d9824c6c9ad0176bbfd3723da1b578b17c256
Reviewed-on: https://chromium-review.googlesource.com/c/1495555
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60001}
2019-03-04 12:25:41 +00:00

36 lines
1.1 KiB
JavaScript

// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --allow-natives-syntax
// This tests that SpeculativeNumberSubtract can still lower to
// Int32Sub in SimplifiedLowering, which requires some magic
// to make sure that SpeculativeNumberSubtract survives to that
// point, especially the JSTypedLowering needs to be unable
// to tell that the inputs to SpeculativeNumberAdd are not
// Number, Undefined, Null or Boolean.
(function() {
// We need a function that has a - with feedback Number or
// NumberOrOddball, but for whose inputs the JSTypedLowering
// cannot reduce it to NumberSubtract (with SpeculativeToNumber
// conversions). We achieve this utilizing an object literal
// indirection here.
function baz(x) {
return {x}.x - x;
}
baz(null);
baz(undefined);
// Now we just need to truncate the result.
function foo(x) {
return baz(42) | 0;
}
%PrepareFunctionForOptimization(foo);
assertEquals(0, foo());
assertEquals(0, foo());
%OptimizeFunctionOnNextCall(foo);
assertEquals(0, foo());
})();