darling-JavaScriptCore/bytecode/FullBytecodeLiveness.h

72 lines
3.0 KiB
C++

/*
* 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 "BytecodeLivenessAnalysis.h"
#include "Operands.h"
#include <wtf/FastBitVector.h>
namespace JSC {
class BytecodeLivenessAnalysis;
class CodeBlock;
// Note: Full bytecode liveness does not track any information about the liveness of temps.
// If you want tmp liveness for a checkpoint ask tmpLivenessForCheckpoint.
class FullBytecodeLiveness {
WTF_MAKE_FAST_ALLOCATED;
public:
const FastBitVector& getLiveness(BytecodeIndex bytecodeIndex, LivenessCalculationPoint point) const
{
// We don't have to worry about overflowing into the next bytecodeoffset in our vectors because we
// static assert that bytecode length is greater than the number of checkpoints in BytecodeStructs.h
switch (point) {
case LivenessCalculationPoint::BeforeUse:
return m_usesBefore[toIndex(bytecodeIndex)];
case LivenessCalculationPoint::AfterUse:
return m_usesAfter[toIndex(bytecodeIndex)];
}
RELEASE_ASSERT_NOT_REACHED();
}
bool virtualRegisterIsLive(VirtualRegister reg, BytecodeIndex bytecodeIndex, LivenessCalculationPoint point) const
{
return virtualRegisterIsAlwaysLive(reg) || virtualRegisterThatIsNotAlwaysLiveIsLive(getLiveness(bytecodeIndex, point), reg);
}
private:
friend class BytecodeLivenessAnalysis;
static size_t toIndex(BytecodeIndex bytecodeIndex) { return bytecodeIndex.offset() + bytecodeIndex.checkpoint(); }
// FIXME: Use FastBitVector's view mechanism to make them compact.
// https://bugs.webkit.org/show_bug.cgi?id=204427
Vector<FastBitVector, 0, UnsafeVectorOverflow> m_usesBefore;
Vector<FastBitVector, 0, UnsafeVectorOverflow> m_usesAfter;
};
} // namespace JSC