v8/test/mjsunit/compiler/number-add.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

65 lines
2.1 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 NumberAdd passes on the right truncations
// even if it figures out during SimplifiedLowering that it
// can indeed do a Word32 operation (based on the feedback
// baked in for its inputs by other operators).
(function() {
// We need a + with Number feedback to get to a NumberAdd
// during the typed lowering pass of TurboFan's frontend.
function foo(x, y) { return x + y; }
foo(0.1, 0.2);
foo(0.1, 0.2);
// Now we need to fool TurboFan to think that it has to
// perform the `foo(x,-1)` on Float64 values until the
// very last moment (after the RETYPE phase of the
// SimplifiedLowering) where it realizes that the inputs
// and outputs of the NumberAdd allow it perform the
// operation on Word32.
function bar(x) {
x = Math.trunc(foo(x - 1, 1));
return foo(x, -1);
}
%PrepareFunctionForOptimization(bar);
assertEquals(0, bar(1));
assertEquals(1, bar(2));
%OptimizeFunctionOnNextCall(bar);
assertEquals(2, bar(3));
})();
// This tests that SpeculativeNumberAdd can still lower to
// Int32Add in SimplifiedLowering, which requires some magic
// to make sure that SpeculativeNumberAdd survives to that
// point, especially the JSTypedLowering needs to be unable
// to tell that the inputs to SpeculativeNumberAdd are non
// String primitives.
(function() {
// We need a function that has a + with feedback Number or
// NumberOrOddball, but for whose inputs the JSTypedLowering
// cannot reduce it to NumberAdd (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(1) | 0;
}
%PrepareFunctionForOptimization(foo);
assertEquals(2, foo());
assertEquals(2, foo());
%OptimizeFunctionOnNextCall(foo);
assertEquals(2, foo());
})();