Reviewers: Kevin Millikin, Description: Check for phi-uses of arguments object before eliminating dead phi's.
HGraphBuilder::TryArgumentsAccess does not emit any uses for receiver and will generate incorrect code when receiver for a property access is defined by a phi
that returns either arguments object or something else. BUG=v8:1582 TEST=test/mjsunit/regress/regress-1582.js Please review this at http://codereview.chromium.org/7553006/ SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/ Affected files: M src/hydrogen.h M src/hydrogen.cc A test/mjsunit/regress/regress-1582.js Index: src/hydrogen.cc =================================================================== --- src/hydrogen.cc (revision 8772) +++ src/hydrogen.cc (working copy) @@ -840,6 +840,19 @@ } +bool HGraph::CheckPhis() { + int block_count = blocks_.length(); + for (int i = 0; i < block_count; ++i) { + for (int j = 0; j < blocks_[i]->phis()->length(); ++j) { + HPhi* phi = blocks_[i]->phis()->at(j); + // We don't support phi uses of arguments for now. + if (phi->CheckFlag(HValue::kIsArguments)) return false; + } + } + return true; +} + + bool HGraph::CollectPhis() { int block_count = blocks_.length(); phi_list_ = new ZoneList<HPhi*>(block_count); @@ -847,8 +860,6 @@ for (int j = 0; j < blocks_[i]->phis()->length(); ++j) { HPhi* phi = blocks_[i]->phis()->at(j); phi_list_->Add(phi); - // We don't support phi uses of arguments for now. - if (phi->CheckFlag(HValue::kIsArguments)) return false; // Check for the hole value (from an uninitialized const). for (int k = 0; k < phi->OperandCount(); k++) { if (phi->OperandAt(k) == GetConstantHole()) return false; @@ -2300,6 +2311,10 @@ graph()->OrderBlocks(); graph()->AssignDominators(); graph()->PropagateDeoptimizingMark(); + if (!graph()->CheckPhis()) { + Bailout("Unsupported phi-use"); + return NULL; + } graph()->EliminateRedundantPhis(); if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis(); if (!graph()->CollectPhis()) { Index: src/hydrogen.h =================================================================== --- src/hydrogen.h (revision 8772) +++ src/hydrogen.h (working copy) @@ -242,6 +242,10 @@ // Returns false if there are phi-uses of the arguments-object // which are not supported by the optimizing compiler. + bool CheckPhis(); + + // Returns false if there are phi-uses of hole values comming + // from uninitialized consts. bool CollectPhis(); Handle<Code> Compile(CompilationInfo* info); Index: test/mjsunit/regress/regress-1582.js =================================================================== --- test/mjsunit/regress/regress-1582.js (revision 0) +++ test/mjsunit/regress/regress-1582.js (revision 0) @@ -0,0 +1,47 @@ +// Copyright 2011 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(restIsArray, rest) { + var arr; + if (typeof rest === "object" && (rest instanceof Array)) { + arr = rest; + } else { + arr = arguments; + } + var i = arr.length; + while (--i >= 0) arr[i]; + var arrIsArguments = (arr[1] !== rest); + assertEquals(restIsArray, arrIsArguments); +} + +f(false, 'b', 'c'); +f(false, 'b', 'c'); +f(false, 'b', 'c'); +%OptimizeFunctionOnNextCall(f); +f(true, ['b', 'c']); -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
