/* * Copyright (C) 2011 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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. */ #ifndef DFGVariableAccessData_h #define DFGVariableAccessData_h #include "PredictedType.h" #include "VirtualRegister.h" #include <wtf/Platform.h> #include <wtf/UnionFind.h> namespace JSC { namespace DFG { class VariableAccessData : public UnionFind<VariableAccessData> { public: VariableAccessData() : m_local(static_cast<VirtualRegister>(std::numeric_limits<int>::min())) , m_prediction(PredictNone) { } VariableAccessData(VirtualRegister local) : m_local(local) , m_prediction(PredictNone) { } VirtualRegister local() { ASSERT(m_local == find()->m_local); return m_local; } int operand() { return static_cast<int>(local()); } bool predict(PredictedType prediction) { return mergePrediction(find()->m_prediction, prediction); } PredictedType prediction() { return find()->m_prediction; } private: // This is slightly space-inefficient, since anything we're unified with // will have the same operand and should have the same prediction. But // putting them here simplifies the code, and we don't expect DFG space // usage for variable access nodes do be significant. VirtualRegister m_local; PredictedType m_prediction; }; } } // namespace JSC::DFG #endif // DFGVariableAccessData_h