From 79a0e3b017510483166feff4eaec4d1fe7e758af Mon Sep 17 00:00:00 2001 From: "ulan@chromium.org" Date: Tue, 22 Jan 2013 13:55:22 +0000 Subject: [PATCH] Fix pattern detection for replacing shifts by rotation. BUG=2499 R=svenpanne@chromium.org Review URL: https://chromiumcodereview.appspot.com/12047015 Patch from Hirofumi Mako . git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13464 ce2b1a6d-e550-0410-aec6-3dcde31c8c00 --- src/hydrogen.cc | 2 ++ test/mjsunit/regress/regress-2499.js | 40 ++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100644 test/mjsunit/regress/regress-2499.js diff --git a/src/hydrogen.cc b/src/hydrogen.cc index 335a40c..eb72a3d 100644 --- a/src/hydrogen.cc +++ b/src/hydrogen.cc @@ -8464,6 +8464,7 @@ static bool ShiftAmountsAllowReplaceByRotate(HValue* sa, HValue* const32_minus_sa) { if (!const32_minus_sa->IsSub()) return false; HSub* sub = HSub::cast(const32_minus_sa); + if (sa != sub->right()) return false; HValue* const32 = sub->left(); if (!const32->IsConstant() || HConstant::cast(const32)->Integer32Value() != 32) { @@ -8492,6 +8493,7 @@ bool HOptimizedGraphBuilder::MatchRotateRight(HValue* left, } else { return false; } + if (shl->left() != shr->left()) return false; if (!ShiftAmountsAllowReplaceByRotate(shl->right(), shr->right()) && !ShiftAmountsAllowReplaceByRotate(shr->right(), shl->right())) { diff --git a/test/mjsunit/regress/regress-2499.js b/test/mjsunit/regress/regress-2499.js new file mode 100644 index 0000000..52aad87 --- /dev/null +++ b/test/mjsunit/regress/regress-2499.js @@ -0,0 +1,40 @@ +// 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 foo(word, nBits) { + return (word[1] >>> nBits) | (word[0] << (32 - nBits)); +} + +word = [0x1001, 0]; + +var expected = foo(word, 1); +foo(word, 1); +%OptimizeFunctionOnNextCall(foo); +var optimized = foo(word, 1); +assertEquals(expected, optimized) -- 2.7.4