darling-JavaScriptCore/bytecode/ArrayAllocationProfile.h
2020-08-29 15:28:47 -04:00

103 lines
3.4 KiB
C++

/*
* Copyright (C) 2012, 2013 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.
*/
#pragma once
#include "IndexingType.h"
#include "JSArray.h"
namespace JSC {
class ArrayAllocationProfile {
public:
ArrayAllocationProfile() = default;
ArrayAllocationProfile(IndexingType recommendedIndexingMode)
{
initializeIndexingMode(recommendedIndexingMode);
}
IndexingType selectIndexingTypeConcurrently()
{
return m_currentIndexingType;
}
IndexingType selectIndexingType()
{
ASSERT(!isCompilationThread());
JSArray* lastArray = m_lastArray;
if (lastArray && UNLIKELY(lastArray->indexingType() != m_currentIndexingType))
updateProfile();
return m_currentIndexingType;
}
// vector length hint becomes [0, BASE_CONTIGUOUS_VECTOR_LEN_MAX].
unsigned vectorLengthHintConcurrently()
{
return m_largestSeenVectorLength;
}
unsigned vectorLengthHint()
{
ASSERT(!isCompilationThread());
JSArray* lastArray = m_lastArray;
if (lastArray && (m_largestSeenVectorLength != BASE_CONTIGUOUS_VECTOR_LEN_MAX) && UNLIKELY(lastArray->getVectorLength() > m_largestSeenVectorLength))
updateProfile();
return m_largestSeenVectorLength;
}
JSArray* updateLastAllocation(JSArray* lastArray)
{
m_lastArray = lastArray;
return lastArray;
}
JS_EXPORT_PRIVATE void updateProfile();
static IndexingType selectIndexingTypeFor(ArrayAllocationProfile* profile)
{
if (!profile)
return ArrayWithUndecided;
return profile->selectIndexingType();
}
static JSArray* updateLastAllocationFor(ArrayAllocationProfile* profile, JSArray* lastArray)
{
if (profile)
profile->updateLastAllocation(lastArray);
return lastArray;
}
void initializeIndexingMode(IndexingType recommendedIndexingMode) { m_currentIndexingType = recommendedIndexingMode; }
private:
IndexingType m_currentIndexingType { ArrayWithUndecided };
unsigned m_largestSeenVectorLength { 0 };
JSArray* m_lastArray { nullptr };
};
} // namespace JSC