Reviewers: Kevin Millikin, Description: HHasInstanceType uses GVN but does not provide a comparison function for its data. This leads to elimination of instance type checks that should not be eliminated.
Provide the data comparison function. BUG=995 Please review this at http://codereview.chromium.org/5898003/ SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/ Affected files: M src/hydrogen-instructions.h A test/mjsunit/regress/regress-995.js Index: src/hydrogen-instructions.h =================================================================== --- src/hydrogen-instructions.h (revision 6051) +++ src/hydrogen-instructions.h (working copy) @@ -2134,6 +2134,12 @@ DECLARE_CONCRETE_INSTRUCTION(HasInstanceType, "has_instance_type") + protected: + virtual bool DataEquals(HValue* other) const { + HHasInstanceType* b = HHasInstanceType::cast(other); + return (from_ == b->from()) && (to_ == b->to()); + } + private: InstanceType from_; InstanceType to_; // Inclusive range, not all combinations work. Index: test/mjsunit/regress/regress-995.js =================================================================== --- test/mjsunit/regress/regress-995.js (revision 0) +++ test/mjsunit/regress/regress-995.js (revision 0) @@ -0,0 +1,39 @@ +// Copyright 2010 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. + +// +// HHasInstanceType did not correctly compare its data during GVN +// causing the %_IsArray in this test to not be executed and its +// result assumed to be the same as the %_IsSpecObject result. +// +// Flags: --allow-natives-syntax + +function f(value) { + if (%_IsSpecObject(value)) { if ((%_IsArray(value))) assertTrue(false); } +} + +f(new String("bar")); -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
