// 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 --opt --no-always-opt // This is a boiled-down example happening in the Epic Citadel demo: // After deopting, the multiplication for unary minus stayed in Smi // mode instead of going to double mode, leading to deopt loops. function unaryMinusTest(x) { var g = (1 << x) | 0; // Optimized code will contain a LMulI with -1 as right operand. return (g & -g) - 1 | 0; } %PrepareFunctionForOptimization(unaryMinusTest); unaryMinusTest(3); unaryMinusTest(3); %OptimizeFunctionOnNextCall(unaryMinusTest); unaryMinusTest(3); assertOptimized(unaryMinusTest); // Deopt on kMinInt unaryMinusTest(31); // The following is normally true, but not with --stress-opt. :-/ // assertUnoptimized(unaryMinusTest); %PrepareFunctionForOptimization(unaryMinusTest); // We should have learned something from the deopt. unaryMinusTest(31); %OptimizeFunctionOnNextCall(unaryMinusTest); unaryMinusTest(31); assertOptimized(unaryMinusTest);