From e1db6d86a97733c2422a4a0087cbb837bbf3351a Mon Sep 17 00:00:00 2001 From: "svenpanne@chromium.org" Date: Mon, 9 Dec 2013 10:15:19 +0000 Subject: [PATCH] Avoid FP exceptions when doing integer division. 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 --- src/hydrogen-instructions.cc | 5 +---- test/mjsunit/div-mul-minus-one.js | 2 -- test/mjsunit/regress/regress-3039.js | 41 ++++++++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+), 6 deletions(-) create mode 100644 test/mjsunit/regress/regress-3039.js diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc index 4f918b3..e7ad219 100644 --- a/src/hydrogen-instructions.cc +++ b/src/hydrogen-instructions.cc @@ -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); } diff --git a/test/mjsunit/div-mul-minus-one.js b/test/mjsunit/div-mul-minus-one.js index f05bf0f..5ade614 100644 --- a/test/mjsunit/div-mul-minus-one.js +++ b/test/mjsunit/div-mul-minus-one.js @@ -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 diff --git a/test/mjsunit/regress/regress-3039.js b/test/mjsunit/regress/regress-3039.js new file mode 100644 index 0000000..3c7f62c --- /dev/null +++ b/test/mjsunit/regress/regress-3039.js @@ -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)); -- 2.7.4