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/*
* Copyright (C) 2012 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.
*/
#include "config.h"
#include "GetByIdStatus.h"
#include "CodeBlock.h"
namespace JSC {
GetByIdStatus GetByIdStatus::computeFor(CodeBlock* profiledBlock, unsigned bytecodeIndex, Identifier& ident)
{
UNUSED_PARAM(profiledBlock);
UNUSED_PARAM(bytecodeIndex);
UNUSED_PARAM(ident);
#if ENABLE(JIT) && ENABLE(VALUE_PROFILER)
// First check if it makes either calls, in which case we want to be super careful, or
// if it's not set at all, in which case we punt.
StructureStubInfo& stubInfo = profiledBlock->getStubInfo(bytecodeIndex);
if (!stubInfo.seen)
return GetByIdStatus(NoInformation, StructureSet(), notFound);
PolymorphicAccessStructureList* list;
int listSize;
switch (stubInfo.accessType) {
case access_get_by_id_self_list:
list = stubInfo.u.getByIdSelfList.structureList;
listSize = stubInfo.u.getByIdSelfList.listSize;
break;
case access_get_by_id_proto_list:
list = stubInfo.u.getByIdProtoList.structureList;
listSize = stubInfo.u.getByIdProtoList.listSize;
break;
default:
list = 0;
listSize = 0;
break;
}
for (int i = 0; i < listSize; ++i) {
if (!list->list[i].isDirect)
return GetByIdStatus(MakesCalls, StructureSet(), notFound);
}
// Next check if it takes slow case, in which case we want to be kind of careful.
if (profiledBlock->likelyToTakeSlowCase(bytecodeIndex))
return GetByIdStatus(TakesSlowPath, StructureSet(), notFound);
// Finally figure out if we can derive an access strategy.
GetByIdStatus result;
switch (stubInfo.accessType) {
case access_unset:
return GetByIdStatus(NoInformation, StructureSet(), notFound);
case access_get_by_id_self: {
Structure* structure = stubInfo.u.getByIdSelf.baseObjectStructure.get();
result.m_offset = structure->get(*profiledBlock->globalData(), ident);
if (result.m_offset != notFound)
result.m_structureSet.add(structure);
if (result.m_offset != notFound)
ASSERT(result.m_structureSet.size());
break;
}
case access_get_by_id_self_list: {
PolymorphicAccessStructureList* list = stubInfo.u.getByIdProtoList.structureList;
unsigned size = stubInfo.u.getByIdProtoList.listSize;
for (unsigned i = 0; i < size; ++i) {
ASSERT(list->list[i].isDirect);
Structure* structure = list->list[i].base.get();
if (result.m_structureSet.contains(structure))
continue;
size_t myOffset = structure->get(*profiledBlock->globalData(), ident);
if (myOffset == notFound) {
result.m_offset = notFound;
break;
}
if (!i)
result.m_offset = myOffset;
else if (result.m_offset != myOffset) {
result.m_offset = notFound;
break;
}
result.m_structureSet.add(structure);
}
if (result.m_offset != notFound)
ASSERT(result.m_structureSet.size());
break;
}
default:
ASSERT(result.m_offset == notFound);
break;
}
if (result.m_offset == notFound) {
result.m_state = TakesSlowPath;
result.m_structureSet.clear();
} else
result.m_state = SimpleDirect;
return result;
#else // ENABLE(JIT)
return GetByIdStatus(NoInformation, StructureSet(), notFound);
#endif // ENABLE(JIT)
}
} // namespace JSC
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