From 7e0ea6ab46391141cd8a6e319adbd4e029d5ac67 Mon Sep 17 00:00:00 2001 From: "verwaest@chromium.org" Date: Wed, 2 Oct 2013 13:24:08 +0000 Subject: [PATCH] Only fold polymorphic into monomorphic load if all load from either receiver or same prototype. R=jkummerow@chromium.org Review URL: https://chromiumcodereview.appspot.com/25718002 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17078 ce2b1a6d-e550-0410-aec6-3dcde31c8c00 --- src/hydrogen.cc | 6 +++- test/mjsunit/regress/regress-polymorphic-load.js | 43 ++++++++++++++++++++++++ 2 files changed, 48 insertions(+), 1 deletion(-) create mode 100644 test/mjsunit/regress/regress-polymorphic-load.js diff --git a/src/hydrogen.cc b/src/hydrogen.cc index f59f988..3705042 100644 --- a/src/hydrogen.cc +++ b/src/hydrogen.cc @@ -4707,10 +4707,14 @@ bool HOptimizedGraphBuilder::PropertyAccessInfo::IsCompatibleForLoad( if (!LookupDescriptor()) return false; if (!lookup_.IsFound()) { - return (!info->lookup_.IsFound() || !info->holder_.is_null()) && + return (!info->lookup_.IsFound() || info->has_holder()) && map_->prototype() == info->map_->prototype(); } + // Mismatch if the other access info found the property in the prototype + // chain. + if (info->has_holder()) return false; + if (lookup_.IsPropertyCallbacks()) { return accessor_.is_identical_to(info->accessor_); } diff --git a/test/mjsunit/regress/regress-polymorphic-load.js b/test/mjsunit/regress/regress-polymorphic-load.js new file mode 100644 index 0000000..2545e85 --- /dev/null +++ b/test/mjsunit/regress/regress-polymorphic-load.js @@ -0,0 +1,43 @@ +// 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 f(o) { + return o.x; +} + +var o1 = {x:1}; +var o2 = {__proto__: {x:2}}; + +f(o2); +f(o2); +f(o2); +f(o1); +%OptimizeFunctionOnNextCall(f); +assertEquals(1, f(o1)); +assertEquals(2, f(o2)); -- 2.7.4