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/*
* Copyright (C) 2013, 2015 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. AND ITS 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 APPLE INC. OR ITS 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.
*/
#pragma once
#include "BytecodeBasicBlock.h"
#include "BytecodeGraph.h"
#include "CodeBlock.h"
#include <wtf/FastBitVector.h>
namespace JSC {
class BytecodeKills;
class FullBytecodeLiveness;
// We model our bytecode effects like the following and insert the liveness calculation points.
//
// <- BeforeUse
// Use
// <- AfterUse
// Use by exception handlers
// Def
enum class LivenessCalculationPoint : uint8_t {
BeforeUse,
AfterUse,
};
class BytecodeLivenessPropagation {
public:
template<typename CodeBlockType, typename UseFunctor>
static void stepOverInstructionUse(CodeBlockType*, const InstructionStream&, BytecodeGraph&, BytecodeIndex, const UseFunctor&);
template<typename CodeBlockType, typename UseFunctor>
static void stepOverInstructionUseInExceptionHandler(CodeBlockType*, const InstructionStream&, BytecodeGraph&, BytecodeIndex, const UseFunctor&);
template<typename CodeBlockType, typename DefFunctor>
static void stepOverInstructionDef(CodeBlockType*, const InstructionStream&, BytecodeGraph&, BytecodeIndex, const DefFunctor&);
template<typename CodeBlockType, typename UseFunctor, typename DefFunctor>
static void stepOverInstruction(CodeBlockType*, const InstructionStream&, BytecodeGraph&, BytecodeIndex, const UseFunctor&, const DefFunctor&);
template<typename CodeBlockType>
static void stepOverInstruction(CodeBlockType*, const InstructionStream&, BytecodeGraph&, BytecodeIndex, FastBitVector& out);
template<typename CodeBlockType, typename Instructions>
static bool computeLocalLivenessForBytecodeIndex(CodeBlockType*, const Instructions&, BytecodeGraph&, BytecodeBasicBlock*, BytecodeIndex, FastBitVector& result);
template<typename CodeBlockType, typename Instructions>
static bool computeLocalLivenessForBlock(CodeBlockType*, const Instructions&, BytecodeGraph&, BytecodeBasicBlock*);
template<typename CodeBlockType, typename Instructions>
static FastBitVector getLivenessInfoAtBytecodeIndex(CodeBlockType*, const Instructions&, BytecodeGraph&, BytecodeIndex);
template<typename CodeBlockType, typename Instructions>
static void runLivenessFixpoint(CodeBlockType*, const Instructions&, BytecodeGraph&);
};
class BytecodeLivenessAnalysis : private BytecodeLivenessPropagation {
WTF_MAKE_FAST_ALLOCATED;
WTF_MAKE_NONCOPYABLE(BytecodeLivenessAnalysis);
public:
friend class BytecodeLivenessPropagation;
BytecodeLivenessAnalysis(CodeBlock*);
FastBitVector getLivenessInfoAtBytecodeIndex(CodeBlock*, BytecodeIndex);
void computeFullLiveness(CodeBlock*, FullBytecodeLiveness& result);
void computeKills(CodeBlock*, BytecodeKills& result);
BytecodeGraph& graph() { return m_graph; }
private:
void dumpResults(CodeBlock*);
void getLivenessInfoAtBytecodeIndex(CodeBlock*, BytecodeIndex, FastBitVector&);
BytecodeGraph m_graph;
};
inline bool operandIsAlwaysLive(int operand);
inline bool operandThatIsNotAlwaysLiveIsLive(const FastBitVector& out, int operand);
inline bool operandIsLive(const FastBitVector& out, int operand);
inline bool isValidRegisterForLiveness(int operand);
} // namespace JSC