fa54dff255
The typing rules for NumberMax and NumberMin didn't properly deal with -0 up until now, leading to suboptimal typing, i.e. for a simple case like Math.max(Math.round(x), 1) TurboFan was unable to figure out that the result is definitely going to be a positive integer in the range [1,inf] or NaN (assuming that NumberOrOddball feedback is used for the value x). Bug: v8:8015 Change-Id: I06e14a9c9b0b813eb214ace7749fcc6ab36bb66a Reviewed-on: https://chromium-review.googlesource.com/1199304 Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Georg Neis <neis@chromium.org> Cr-Commit-Position: refs/heads/master@{#55570}
39 lines
1018 B
JavaScript
39 lines
1018 B
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
|
|
|
|
// Test the case where TurboFan can statically rule out -0 from the
|
|
// Math.max type.
|
|
(function() {
|
|
function foo(x) {
|
|
// Arrange x such that TurboFan infers type [-inf, inf] \/ MinusZero.
|
|
x = +x;
|
|
x = Math.round(x);
|
|
return Object.is(-0, Math.max(1, x))
|
|
}
|
|
|
|
assertFalse(foo(-0));
|
|
assertFalse(foo(-1));
|
|
%OptimizeFunctionOnNextCall(foo);
|
|
assertFalse(foo(-0));
|
|
assertFalse(foo(-1));
|
|
})();
|
|
|
|
// Test the case where -0 is ruled out because it's strictly less than +0.
|
|
(function() {
|
|
function foo(x) {
|
|
// Arrange x such that TurboFan infers type [-inf, inf] \/ MinusZero.
|
|
x = +x;
|
|
x = Math.round(x);
|
|
return Object.is(-0, Math.max(0, x))
|
|
}
|
|
|
|
assertFalse(foo(-0));
|
|
assertFalse(foo(-1));
|
|
%OptimizeFunctionOnNextCall(foo);
|
|
assertFalse(foo(-0));
|
|
assertFalse(foo(-1));
|
|
})();
|