v8/test/mjsunit/compiler/stubs/floor-stub.js
danno abc35080b3 Add a MathFloor stub generated with TurboFan
This stub will be used as the basis of a Math.floor-specific CallIC to
detect and track calls to floor that return -0.

Along the way:
- Create a TurboFanCodeStub super class from which the StringLength and
MathRound TF stubs derive.
- Fix the ugly hack that passes the first stub parameter as the "this"
pointer in the the TF-compiled JS function.
- Fix bugs in the ia32/x64 disassembler.

Review URL: https://codereview.chromium.org/1137703002

Cr-Commit-Position: refs/heads/master@{#28339}
2015-05-11 11:45:02 +00:00

54 lines
2.7 KiB
JavaScript

// Copyright 2015 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Flags: --allow-natives-syntax --expose-natives-as=builtins --noalways-opt
const kExtraTypeFeedbackMinusZeroSentinel = 1;
const kFirstSlotExtraTypeFeedbackIndex = 5;
(function(){
var floorFunc = function() {
Math.floor(NaN);
}
// Execute the function once to make sure it has a type feedback vector.
floorFunc(5);
assertTrue(kExtraTypeFeedbackMinusZeroSentinel !==
%FixedArrayGet(%GetTypeFeedbackVector(floorFunc),
kFirstSlotExtraTypeFeedbackIndex));
assertEquals(5.0, builtins.MathFloor_STUB(floorFunc, 4, 5.5));
assertTrue(kExtraTypeFeedbackMinusZeroSentinel !==
%FixedArrayGet(%GetTypeFeedbackVector(floorFunc),
kFirstSlotExtraTypeFeedbackIndex));
// Executing floor such that it returns -0 should set the proper sentinel in
// the feedback vector.
assertEquals(-Infinity, 1/builtins.MathFloor_STUB(floorFunc, 4, -0));
assertEquals(kExtraTypeFeedbackMinusZeroSentinel,
%FixedArrayGet(%GetTypeFeedbackVector(floorFunc),
kFirstSlotExtraTypeFeedbackIndex));
%ClearFunctionTypeFeedback(floorFunc);
})();