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Avoid FP exceptions when doing integer division.

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BUG=v8:3039
R=titzer@chromium.org

Review URL: https://codereview.chromium.org/104003004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18277 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
svenpanne@chromium.org 2013-12-09 10:15:19 +00:00
parent ab03fd5022
commit e1db6d86a9
3 changed files with 42 additions and 6 deletions
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5
src/hydrogen-instructions.cc
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@ -1776,10 +1776,7 @@ Range* HDiv::InferRange(Zone* zone) {
result->set_can_be_minus_zero(!CheckFlag(kAllUsesTruncatingToInt32) &&
(a->CanBeMinusZero() ||
(a->CanBeZero() && b->CanBeNegative())));
if (!a->Includes(kMinInt) ||
!b->Includes(-1) ||
CheckFlag(kAllUsesTruncatingToInt32)) {
// It is safe to clear kCanOverflow when kAllUsesTruncatingToInt32.
if (!a->Includes(kMinInt) || !b->Includes(-1)) {
ClearFlag(HValue::kCanOverflow);
}

2
test/mjsunit/div-mul-minus-one.js
View File

@ -36,9 +36,7 @@ var expected_MinInt = div(kMinInt);
var expected_minus_zero = div(0);
%OptimizeFunctionOnNextCall(div);
assertEquals(expected_MinInt, div(kMinInt));
assertOptimized(div);
assertEquals(expected_minus_zero , div(0));
assertOptimized(div);
function mul(g) {
return (g * -1) ^ 1

41
test/mjsunit/regress/regress-3039.js Normal file
View File

@ -0,0 +1,41 @@
// Copyright 2013 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
function do_div(x, y) {
return (x / y) | 0;
}
// Preparation.
assertEquals(17, do_div(51, 3));
assertEquals(13, do_div(65, 5));
%OptimizeFunctionOnNextCall(do_div);
assertEquals(11, do_div(77, 7));
// The actual test. We should not trigger a floating point exception.
assertEquals(-2147483648, do_div(-2147483648, -1));