bf71023ba5
This fixes a deopt loop in the Epic Citadel demo and removes some code. Apart from that, this change is performance-neutral. When we do something similar for BIT_NOT, the whole UnaryOp stuff can go away. R=jkummerow@chromium.org Review URL: https://codereview.chromium.org/21782002 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16029 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
56 lines
2.4 KiB
JavaScript
56 lines
2.4 KiB
JavaScript
// Copyright 2013 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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// Flags: --allow-natives-syntax
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// This is a boiled-down example happening in the Epic Citadel demo:
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// After deopting, the multiplication for unary minus stayed in Smi
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// mode instead of going to double mode, leading to deopt loops.
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function unaryMinusTest(x) {
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var g = (1 << x) | 0;
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// Optimized code will contain a LMulI with -1 as right operand.
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return (g & -g) - 1 | 0;
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}
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unaryMinusTest(3);
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unaryMinusTest(3);
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%OptimizeFunctionOnNextCall(unaryMinusTest);
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unaryMinusTest(3);
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assertOptimized(unaryMinusTest);
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// Deopt on kMinInt
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unaryMinusTest(31);
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// The following is normally true, but not with --stress-opt. :-/
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// assertUnoptimized(unaryMinusTest);
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// We should have learned something from the deopt.
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unaryMinusTest(31);
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%OptimizeFunctionOnNextCall(unaryMinusTest);
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unaryMinusTest(31);
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assertOptimized(unaryMinusTest);
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