Example #1
0
GetByIdStatus GetByIdStatus::computeFromLLInt(CodeBlock* profiledBlock, unsigned bytecodeIndex, UniquedStringImpl* uid)
{
    UNUSED_PARAM(profiledBlock);
    UNUSED_PARAM(bytecodeIndex);
    UNUSED_PARAM(uid);

    VM& vm = *profiledBlock->vm();
    
    Instruction* instruction = profiledBlock->instructions().begin() + bytecodeIndex;
    
    if (instruction[0].u.opcode == LLInt::getOpcode(op_get_array_length))
        return GetByIdStatus(NoInformation, false);

    StructureID structureID = instruction[4].u.structureID;
    if (!structureID)
        return GetByIdStatus(NoInformation, false);

    Structure* structure = vm.heap.structureIDTable().get(structureID);

    if (structure->takesSlowPathInDFGForImpureProperty())
        return GetByIdStatus(NoInformation, false);

    unsigned attributesIgnored;
    PropertyOffset offset = structure->getConcurrently(uid, attributesIgnored);
    if (!isValidOffset(offset))
        return GetByIdStatus(NoInformation, false);
    
    return GetByIdStatus(Simple, false, GetByIdVariant(StructureSet(structure), offset));
}
Example #2
0
GetByIdStatus GetByIdStatus::computeFor(const StructureSet& set, StringImpl* uid)
{
    // For now we only handle the super simple self access case. We could handle the
    // prototype case in the future.
    
    if (set.isEmpty())
        return GetByIdStatus();

    if (toUInt32FromStringImpl(uid) != PropertyName::NotAnIndex)
        return GetByIdStatus(TakesSlowPath);
    
    GetByIdStatus result;
    result.m_state = Simple;
    result.m_wasSeenInJIT = false;
    for (unsigned i = 0; i < set.size(); ++i) {
        Structure* structure = set[i];
        if (structure->typeInfo().overridesGetOwnPropertySlot() && structure->typeInfo().type() != GlobalObjectType)
            return GetByIdStatus(TakesSlowPath);
        
        if (!structure->propertyAccessesAreCacheable())
            return GetByIdStatus(TakesSlowPath);
        
        unsigned attributes;
        PropertyOffset offset = structure->getConcurrently(uid, attributes);
        if (!isValidOffset(offset))
            return GetByIdStatus(TakesSlowPath); // It's probably a prototype lookup. Give up on life for now, even though we could totally be way smarter about it.
        if (attributes & Accessor)
            return GetByIdStatus(MakesCalls); // We could be smarter here, like strenght-reducing this to a Call.
        
        if (!result.appendVariant(GetByIdVariant(structure, offset)))
            return GetByIdStatus(TakesSlowPath);
    }
    
    return result;
}
GetByIdStatus GetByIdStatus::computeFromLLInt(CodeBlock* profiledBlock, unsigned bytecodeIndex, StringImpl* uid)
{
    UNUSED_PARAM(profiledBlock);
    UNUSED_PARAM(bytecodeIndex);
    UNUSED_PARAM(uid);
#if ENABLE(LLINT)
    Instruction* instruction = profiledBlock->instructions().begin() + bytecodeIndex;
    
    if (instruction[0].u.opcode == LLInt::getOpcode(llint_op_get_array_length))
        return GetByIdStatus(NoInformation, false);

    Structure* structure = instruction[4].u.structure.get();
    if (!structure)
        return GetByIdStatus(NoInformation, false);

    if (structure->takesSlowPathInDFGForImpureProperty())
        return GetByIdStatus(NoInformation, false);

    unsigned attributesIgnored;
    JSCell* specificValue;
    PropertyOffset offset = structure->getConcurrently(
        *profiledBlock->vm(), uid, attributesIgnored, specificValue);
    if (structure->isDictionary())
        specificValue = 0;
    if (!isValidOffset(offset))
        return GetByIdStatus(NoInformation, false);
    
    return GetByIdStatus(Simple, false, StructureSet(structure), offset, specificValue);
#else
    return GetByIdStatus(NoInformation, false);
#endif
}
PutByIdStatus PutByIdStatus::computeFromLLInt(CodeBlock* profiledBlock, unsigned bytecodeIndex, UniquedStringImpl* uid)
{
    UNUSED_PARAM(profiledBlock);
    UNUSED_PARAM(bytecodeIndex);
    UNUSED_PARAM(uid);

    VM& vm = *profiledBlock->vm();
    
    Instruction* instruction = profiledBlock->instructions().begin() + bytecodeIndex;

    StructureID structureID = instruction[4].u.structureID;
    if (!structureID)
        return PutByIdStatus(NoInformation);
    
    Structure* structure = vm.heap.structureIDTable().get(structureID);

    StructureID newStructureID = instruction[6].u.structureID;
    if (!newStructureID) {
        PropertyOffset offset = structure->getConcurrently(uid);
        if (!isValidOffset(offset))
            return PutByIdStatus(NoInformation);
        
        return PutByIdVariant::replace(structure, offset, structure->inferredTypeDescriptorFor(uid));
    }

    Structure* newStructure = vm.heap.structureIDTable().get(newStructureID);
    
    ASSERT(structure->transitionWatchpointSetHasBeenInvalidated());
    
    PropertyOffset offset = newStructure->getConcurrently(uid);
    if (!isValidOffset(offset))
        return PutByIdStatus(NoInformation);
    
    ObjectPropertyConditionSet conditionSet;
    if (!(instruction[8].u.putByIdFlags & PutByIdIsDirect)) {
        conditionSet =
            generateConditionsForPropertySetterMissConcurrently(
                *profiledBlock->vm(), profiledBlock->globalObject(), structure, uid);
        if (!conditionSet.isValid())
            return PutByIdStatus(NoInformation);
    }
    
    return PutByIdVariant::transition(
        structure, newStructure, conditionSet, offset, newStructure->inferredTypeDescriptorFor(uid));
}
Example #5
0
PutByIdStatus PutByIdStatus::computeFromLLInt(CodeBlock* profiledBlock, unsigned bytecodeIndex, StringImpl* uid)
{
    UNUSED_PARAM(profiledBlock);
    UNUSED_PARAM(bytecodeIndex);
    UNUSED_PARAM(uid);
    Instruction* instruction = profiledBlock->instructions().begin() + bytecodeIndex;

    Structure* structure = instruction[4].u.structure.get();
    if (!structure)
        return PutByIdStatus(NoInformation);
    
    if (instruction[0].u.opcode == LLInt::getOpcode(op_put_by_id)
        || instruction[0].u.opcode == LLInt::getOpcode(op_put_by_id_out_of_line)) {
        PropertyOffset offset = structure->getConcurrently(uid);
        if (!isValidOffset(offset))
            return PutByIdStatus(NoInformation);
        
        return PutByIdVariant::replace(structure, offset);
    }
    
    ASSERT(structure->transitionWatchpointSetHasBeenInvalidated());
    
    ASSERT(instruction[0].u.opcode == LLInt::getOpcode(op_put_by_id_transition_direct)
        || instruction[0].u.opcode == LLInt::getOpcode(op_put_by_id_transition_normal)
        || instruction[0].u.opcode == LLInt::getOpcode(op_put_by_id_transition_direct_out_of_line)
        || instruction[0].u.opcode == LLInt::getOpcode(op_put_by_id_transition_normal_out_of_line));
    
    Structure* newStructure = instruction[6].u.structure.get();
    StructureChain* chain = instruction[7].u.structureChain.get();
    ASSERT(newStructure);
    ASSERT(chain);
    
    PropertyOffset offset = newStructure->getConcurrently(uid);
    if (!isValidOffset(offset))
        return PutByIdStatus(NoInformation);
    
    RefPtr<IntendedStructureChain> intendedChain;
    if (chain)
        intendedChain = adoptRef(new IntendedStructureChain(profiledBlock, structure, chain));
    
    return PutByIdVariant::transition(structure, newStructure, intendedChain.get(), offset);
}
Example #6
0
bool GetByIdStatus::computeForChain(CodeBlock* profiledBlock, StringImpl* uid, PassRefPtr<IntendedStructureChain> passedChain)
{
#if ENABLE(JIT)
    RefPtr<IntendedStructureChain> chain = passedChain;

    // Validate the chain. If the chain is invalid, then currently the best thing
    // we can do is to assume that TakesSlow is true. In the future, it might be
    // worth exploring reifying the structure chain from the structure we've got
    // instead of using the one from the cache, since that will do the right things
    // if the structure chain has changed. But that may be harder, because we may
    // then end up having a different type of access altogether. And it currently
    // does not appear to be worth it to do so -- effectively, the heuristic we
    // have now is that if the structure chain has changed between when it was
    // cached on in the baseline JIT and when the DFG tried to inline the access,
    // then we fall back on a polymorphic access.
    if (!chain->isStillValid())
        return false;

    if (chain->head()->takesSlowPathInDFGForImpureProperty())
        return false;
    size_t chainSize = chain->size();
    for (size_t i = 0; i < chainSize; i++) {
        if (chain->at(i)->takesSlowPathInDFGForImpureProperty())
            return false;
    }

    JSObject* currentObject = chain->terminalPrototype();
    Structure* currentStructure = chain->last();

    ASSERT_UNUSED(currentObject, currentObject);

    unsigned attributesIgnored;
    JSCell* specificValue;

    PropertyOffset offset = currentStructure->getConcurrently(
                                *profiledBlock->vm(), uid, attributesIgnored, specificValue);
    if (currentStructure->isDictionary())
        specificValue = 0;
    if (!isValidOffset(offset))
        return false;

    m_variants.append(
        GetByIdVariant(StructureSet(chain->head()), offset, specificValue, chain));
    return true;
#else // ENABLE(JIT)
    UNUSED_PARAM(profiledBlock);
    UNUSED_PARAM(uid);
    UNUSED_PARAM(passedChain);
    UNREACHABLE_FOR_PLATFORM();
    return false;
#endif // ENABLE(JIT)
}
Example #7
0
ComplexGetStatus ComplexGetStatus::computeFor(
    CodeBlock* profiledBlock, Structure* headStructure, StructureChain* chain,
    unsigned chainCount, AtomicStringImpl* uid)
{
    // FIXME: We should assert that we never see a structure that
    // hasImpureGetOwnPropertySlot() but for which we don't
    // newImpurePropertyFiresWatchpoints(). We're not at a point where we can do
    // that, yet.
    // https://bugs.webkit.org/show_bug.cgi?id=131810
    
    if (headStructure->takesSlowPathInDFGForImpureProperty())
        return takesSlowPath();
    
    ComplexGetStatus result;
    result.m_kind = Inlineable;
    
    if (chain && chainCount) {
        result.m_chain = adoptRef(new IntendedStructureChain(
            profiledBlock, headStructure, chain, chainCount));
        
        if (!result.m_chain->isStillValid())
            return skip();
        
        if (headStructure->takesSlowPathInDFGForImpureProperty()
            || result.m_chain->takesSlowPathInDFGForImpureProperty())
            return takesSlowPath();
        
        JSObject* currentObject = result.m_chain->terminalPrototype();
        Structure* currentStructure = result.m_chain->last();
        
        ASSERT_UNUSED(currentObject, currentObject);
        
        result.m_offset = currentStructure->getConcurrently(uid, result.m_attributes);
    } else {
        result.m_offset = headStructure->getConcurrently(uid, result.m_attributes);
    }
    
    if (!isValidOffset(result.m_offset))
        return takesSlowPath();
    
    return result;
}
Example #8
0
GetByIdStatus GetByIdStatus::computeForStubInfo(
    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo, StringImpl* uid,
    CallLinkStatus::ExitSiteData callExitSiteData)
{
    if (!stubInfo || !stubInfo->seen)
        return GetByIdStatus(NoInformation);
    
    PolymorphicGetByIdList* list = 0;
    State slowPathState = TakesSlowPath;
    if (stubInfo->accessType == access_get_by_id_list) {
        list = stubInfo->u.getByIdList.list;
        for (unsigned i = 0; i < list->size(); ++i) {
            const GetByIdAccess& access = list->at(i);
            if (access.doesCalls())
                slowPathState = MakesCalls;
        }
    }
    
    // Finally figure out if we can derive an access strategy.
    GetByIdStatus result;
    result.m_state = Simple;
    result.m_wasSeenInJIT = true; // This is interesting for bytecode dumping only.
    switch (stubInfo->accessType) {
    case access_unset:
        return GetByIdStatus(NoInformation);
        
    case access_get_by_id_self: {
        Structure* structure = stubInfo->u.getByIdSelf.baseObjectStructure.get();
        if (structure->takesSlowPathInDFGForImpureProperty())
            return GetByIdStatus(slowPathState, true);
        unsigned attributesIgnored;
        GetByIdVariant variant;
        variant.m_offset = structure->getConcurrently(uid, attributesIgnored);
        if (!isValidOffset(variant.m_offset))
            return GetByIdStatus(slowPathState, true);
        
        variant.m_structureSet.add(structure);
        bool didAppend = result.appendVariant(variant);
        ASSERT_UNUSED(didAppend, didAppend);
        return result;
    }
        
    case access_get_by_id_list: {
        for (unsigned listIndex = 0; listIndex < list->size(); ++listIndex) {
            Structure* structure = list->at(listIndex).structure();
            
            ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
                profiledBlock, structure, list->at(listIndex).chain(),
                list->at(listIndex).chainCount(), uid);
             
            switch (complexGetStatus.kind()) {
            case ComplexGetStatus::ShouldSkip:
                continue;
                 
            case ComplexGetStatus::TakesSlowPath:
                return GetByIdStatus(slowPathState, true);
                 
            case ComplexGetStatus::Inlineable: {
                std::unique_ptr<CallLinkStatus> callLinkStatus;
                switch (list->at(listIndex).type()) {
                case GetByIdAccess::SimpleInline:
                case GetByIdAccess::SimpleStub: {
                    break;
                }
                case GetByIdAccess::Getter: {
                    AccessorCallJITStubRoutine* stub = static_cast<AccessorCallJITStubRoutine*>(
                        list->at(listIndex).stubRoutine());
                    callLinkStatus = std::make_unique<CallLinkStatus>(
                        CallLinkStatus::computeFor(
                            locker, profiledBlock, *stub->m_callLinkInfo, callExitSiteData));
                    break;
                }
                case GetByIdAccess::CustomGetter:
                case GetByIdAccess::WatchedStub:{
                    // FIXME: It would be totally sweet to support this at some point in the future.
                    // https://bugs.webkit.org/show_bug.cgi?id=133052
                    return GetByIdStatus(slowPathState, true);
                }
                default:
                    RELEASE_ASSERT_NOT_REACHED();
                }
                 
                GetByIdVariant variant(
                    StructureSet(structure), complexGetStatus.offset(), complexGetStatus.chain(),
                    std::move(callLinkStatus));
                 
                if (!result.appendVariant(variant))
                    return GetByIdStatus(slowPathState, true);
                break;
            } }
        }
        
        return result;
    }
        
    default:
        return GetByIdStatus(slowPathState, true);
    }
    
    RELEASE_ASSERT_NOT_REACHED();
    return GetByIdStatus();
}
Example #9
0
GetByIdStatus GetByIdStatus::computeForStubInfoWithoutExitSiteFeedback(
    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo, UniquedStringImpl* uid,
    CallLinkStatus::ExitSiteData callExitSiteData)
{
    if (!stubInfo || !stubInfo->everConsidered)
        return GetByIdStatus(NoInformation);

    PolymorphicAccess* list = 0;
    State slowPathState = TakesSlowPath;
    if (stubInfo->cacheType == CacheType::Stub) {
        list = stubInfo->u.stub;
        for (unsigned i = 0; i < list->size(); ++i) {
            const AccessCase& access = list->at(i);
            if (access.doesCalls())
                slowPathState = MakesCalls;
        }
    }
    
    if (stubInfo->tookSlowPath)
        return GetByIdStatus(slowPathState);
    
    // Finally figure out if we can derive an access strategy.
    GetByIdStatus result;
    result.m_state = Simple;
    result.m_wasSeenInJIT = true; // This is interesting for bytecode dumping only.
    switch (stubInfo->cacheType) {
    case CacheType::Unset:
        return GetByIdStatus(NoInformation);
        
    case CacheType::GetByIdSelf: {
        Structure* structure = stubInfo->u.byIdSelf.baseObjectStructure.get();
        if (structure->takesSlowPathInDFGForImpureProperty())
            return GetByIdStatus(slowPathState, true);
        unsigned attributesIgnored;
        GetByIdVariant variant;
        variant.m_offset = structure->getConcurrently(uid, attributesIgnored);
        if (!isValidOffset(variant.m_offset))
            return GetByIdStatus(slowPathState, true);
        
        variant.m_structureSet.add(structure);
        bool didAppend = result.appendVariant(variant);
        ASSERT_UNUSED(didAppend, didAppend);
        return result;
    }
        
    case CacheType::Stub: {
        for (unsigned listIndex = 0; listIndex < list->size(); ++listIndex) {
            const AccessCase& access = list->at(listIndex);
            if (access.viaProxy())
                return GetByIdStatus(slowPathState, true);
            
            Structure* structure = access.structure();
            if (!structure) {
                // The null structure cases arise due to array.length and string.length. We have no way
                // of creating a GetByIdVariant for those, and we don't really have to since the DFG
                // handles those cases in FixupPhase using value profiling. That's a bit awkward - we
                // shouldn't have to use value profiling to discover something that the AccessCase
                // could have told us. But, it works well enough. So, our only concern here is to not
                // crash on null structure.
                return GetByIdStatus(slowPathState, true);
            }
            
            ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
                structure, access.conditionSet(), uid);
             
            switch (complexGetStatus.kind()) {
            case ComplexGetStatus::ShouldSkip:
                continue;
                 
            case ComplexGetStatus::TakesSlowPath:
                return GetByIdStatus(slowPathState, true);
                 
            case ComplexGetStatus::Inlineable: {
                std::unique_ptr<CallLinkStatus> callLinkStatus;
                JSFunction* intrinsicFunction = nullptr;

                switch (access.type()) {
                case AccessCase::Load: {
                    break;
                }
                case AccessCase::IntrinsicGetter: {
                    intrinsicFunction = access.intrinsicFunction();
                    break;
                }
                case AccessCase::Getter: {
                    CallLinkInfo* callLinkInfo = access.callLinkInfo();
                    ASSERT(callLinkInfo);
                    callLinkStatus = std::make_unique<CallLinkStatus>(
                        CallLinkStatus::computeFor(
                            locker, profiledBlock, *callLinkInfo, callExitSiteData));
                    break;
                }
                default: {
                    // FIXME: It would be totally sweet to support more of these at some point in the
                    // future. https://bugs.webkit.org/show_bug.cgi?id=133052
                    return GetByIdStatus(slowPathState, true);
                } }
                 
                GetByIdVariant variant(
                    StructureSet(structure), complexGetStatus.offset(),
                    complexGetStatus.conditionSet(), WTFMove(callLinkStatus),
                    intrinsicFunction);

                if (!result.appendVariant(variant))
                    return GetByIdStatus(slowPathState, true);
                break;
            } }
        }
        
        return result;
    }
        
    default:
        return GetByIdStatus(slowPathState, true);
    }
    
    RELEASE_ASSERT_NOT_REACHED();
    return GetByIdStatus();
}
GetByIdStatus GetByIdStatus::computeFor(CodeBlock* profiledBlock, StubInfoMap& map, unsigned bytecodeIndex, StringImpl* uid)
{
    ConcurrentJITLocker locker(profiledBlock->m_lock);
    
    UNUSED_PARAM(profiledBlock);
    UNUSED_PARAM(bytecodeIndex);
    UNUSED_PARAM(uid);
#if ENABLE(JIT)
    StructureStubInfo* stubInfo = map.get(CodeOrigin(bytecodeIndex));
    if (!stubInfo || !stubInfo->seen)
        return computeFromLLInt(profiledBlock, bytecodeIndex, uid);
    
    if (stubInfo->resetByGC)
        return GetByIdStatus(TakesSlowPath, true);

    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, true);
    }
    
    // Next check if it takes slow case, in which case we want to be kind of careful.
    if (profiledBlock->likelyToTakeSlowCase(bytecodeIndex))
        return GetByIdStatus(TakesSlowPath, true);
    
    // Finally figure out if we can derive an access strategy.
    GetByIdStatus result;
    result.m_wasSeenInJIT = true; // This is interesting for bytecode dumping only.
    switch (stubInfo->accessType) {
    case access_unset:
        return computeFromLLInt(profiledBlock, bytecodeIndex, uid);
        
    case access_get_by_id_self: {
        Structure* structure = stubInfo->u.getByIdSelf.baseObjectStructure.get();
        if (structure->takesSlowPathInDFGForImpureProperty())
            return GetByIdStatus(TakesSlowPath, true);
        unsigned attributesIgnored;
        JSCell* specificValue;
        result.m_offset = structure->getConcurrently(
            *profiledBlock->vm(), uid, attributesIgnored, specificValue);
        if (structure->isDictionary())
            specificValue = 0;
        
        if (isValidOffset(result.m_offset)) {
            result.m_structureSet.add(structure);
            result.m_specificValue = JSValue(specificValue);
        }
        
        if (isValidOffset(result.m_offset))
            ASSERT(result.m_structureSet.size());
        break;
    }
        
    case access_get_by_id_self_list: {
        for (int i = 0; i < listSize; ++i) {
            ASSERT(list->list[i].isDirect);
            
            Structure* structure = list->list[i].base.get();
            if (structure->takesSlowPathInDFGForImpureProperty())
                return GetByIdStatus(TakesSlowPath, true);

            if (result.m_structureSet.contains(structure))
                continue;
            
            unsigned attributesIgnored;
            JSCell* specificValue;
            PropertyOffset myOffset = structure->getConcurrently(
                *profiledBlock->vm(), uid, attributesIgnored, specificValue);
            if (structure->isDictionary())
                specificValue = 0;
            
            if (!isValidOffset(myOffset)) {
                result.m_offset = invalidOffset;
                break;
            }
                    
            if (!i) {
                result.m_offset = myOffset;
                result.m_specificValue = JSValue(specificValue);
            } else if (result.m_offset != myOffset) {
                result.m_offset = invalidOffset;
                break;
            } else if (result.m_specificValue != JSValue(specificValue))
                result.m_specificValue = JSValue();
            
            result.m_structureSet.add(structure);
        }
                    
        if (isValidOffset(result.m_offset))
            ASSERT(result.m_structureSet.size());
        break;
    }
        
    case access_get_by_id_proto: {
        if (!stubInfo->u.getByIdProto.isDirect)
            return GetByIdStatus(MakesCalls, true);
        result.m_chain = adoptRef(new IntendedStructureChain(
            profiledBlock,
            stubInfo->u.getByIdProto.baseObjectStructure.get(),
            stubInfo->u.getByIdProto.prototypeStructure.get()));
        computeForChain(result, profiledBlock, uid);
        break;
    }
        
    case access_get_by_id_chain: {
        if (!stubInfo->u.getByIdChain.isDirect)
            return GetByIdStatus(MakesCalls, true);
        result.m_chain = adoptRef(new IntendedStructureChain(
            profiledBlock,
            stubInfo->u.getByIdChain.baseObjectStructure.get(),
            stubInfo->u.getByIdChain.chain.get(),
            stubInfo->u.getByIdChain.count));
        computeForChain(result, profiledBlock, uid);
        break;
    }
        
    default:
        ASSERT(!isValidOffset(result.m_offset));
        break;
    }
    
    if (!isValidOffset(result.m_offset)) {
        result.m_state = TakesSlowPath;
        result.m_structureSet.clear();
        result.m_chain.clear();
        result.m_specificValue = JSValue();
    } else
        result.m_state = Simple;
    
    return result;
#else // ENABLE(JIT)
    UNUSED_PARAM(map);
    return GetByIdStatus(NoInformation, false);
#endif // ENABLE(JIT)
}
Example #11
0
GetByIdStatus GetByIdStatus::computeForStubInfo(
    const ConcurrentJITLocker&, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
    StringImpl* uid)
{
    if (!stubInfo || !stubInfo->seen)
        return GetByIdStatus(NoInformation);
    
    if (stubInfo->resetByGC)
        return GetByIdStatus(TakesSlowPath, true);

    PolymorphicGetByIdList* list = 0;
    if (stubInfo->accessType == access_get_by_id_list) {
        list = stubInfo->u.getByIdList.list;
        for (unsigned i = 0; i < list->size(); ++i) {
            if (list->at(i).doesCalls())
                return GetByIdStatus(MakesCalls, true);
        }
    }
    
    // Finally figure out if we can derive an access strategy.
    GetByIdStatus result;
    result.m_state = Simple;
    result.m_wasSeenInJIT = true; // This is interesting for bytecode dumping only.
    switch (stubInfo->accessType) {
    case access_unset:
        return GetByIdStatus(NoInformation);
        
    case access_get_by_id_self: {
        Structure* structure = stubInfo->u.getByIdSelf.baseObjectStructure.get();
        if (structure->takesSlowPathInDFGForImpureProperty())
            return GetByIdStatus(TakesSlowPath, true);
        unsigned attributesIgnored;
        JSCell* specificValue;
        GetByIdVariant variant;
        variant.m_offset = structure->getConcurrently(
            *profiledBlock->vm(), uid, attributesIgnored, specificValue);
        if (!isValidOffset(variant.m_offset))
            return GetByIdStatus(TakesSlowPath, true);
        
        if (structure->isDictionary())
            specificValue = 0;
        
        variant.m_structureSet.add(structure);
        variant.m_specificValue = JSValue(specificValue);
        result.appendVariant(variant);
        return result;
    }
        
    case access_get_by_id_list: {
        for (unsigned listIndex = 0; listIndex < list->size(); ++listIndex) {
            ASSERT(!list->at(listIndex).doesCalls());
            
            Structure* structure = list->at(listIndex).structure();
            if (structure->takesSlowPathInDFGForImpureProperty())
                return GetByIdStatus(TakesSlowPath, true);
            
            if (list->at(listIndex).chain()) {
                RefPtr<IntendedStructureChain> chain = adoptRef(new IntendedStructureChain(
                    profiledBlock, structure, list->at(listIndex).chain(),
                    list->at(listIndex).chainCount()));
                if (!result.computeForChain(profiledBlock, uid, chain))
                    return GetByIdStatus(TakesSlowPath, true);
                continue;
            }
            
            unsigned attributesIgnored;
            JSCell* specificValue;
            PropertyOffset myOffset = structure->getConcurrently(
                *profiledBlock->vm(), uid, attributesIgnored, specificValue);
            if (structure->isDictionary())
                specificValue = 0;
            
            if (!isValidOffset(myOffset))
                return GetByIdStatus(TakesSlowPath, true);

            bool found = false;
            for (unsigned variantIndex = 0; variantIndex < result.m_variants.size(); ++variantIndex) {
                GetByIdVariant& variant = result.m_variants[variantIndex];
                if (variant.m_chain)
                    continue;
                
                if (variant.m_offset != myOffset)
                    continue;

                found = true;
                if (variant.m_structureSet.contains(structure))
                    break;
                
                if (variant.m_specificValue != JSValue(specificValue))
                    variant.m_specificValue = JSValue();
                
                variant.m_structureSet.add(structure);
                break;
            }
            
            if (found)
                continue;
            
            if (!result.appendVariant(GetByIdVariant(StructureSet(structure), myOffset, specificValue)))
                return GetByIdStatus(TakesSlowPath, true);
        }
        
        return result;
    }
        
    case access_get_by_id_chain: {
        if (!stubInfo->u.getByIdChain.isDirect)
            return GetByIdStatus(MakesCalls, true);
        RefPtr<IntendedStructureChain> chain = adoptRef(new IntendedStructureChain(
            profiledBlock,
            stubInfo->u.getByIdChain.baseObjectStructure.get(),
            stubInfo->u.getByIdChain.chain.get(),
            stubInfo->u.getByIdChain.count));
        if (result.computeForChain(profiledBlock, uid, chain))
            return result;
        return GetByIdStatus(TakesSlowPath, true);
    }
        
    default:
        return GetByIdStatus(TakesSlowPath, true);
    }
    
    RELEASE_ASSERT_NOT_REACHED();
    return GetByIdStatus();
}
Example #12
0
PutByIdStatus PutByIdStatus::computeFor(JSGlobalObject* globalObject, const StructureSet& set, StringImpl* uid, bool isDirect)
{
    if (toUInt32FromStringImpl(uid) != PropertyName::NotAnIndex)
        return PutByIdStatus(TakesSlowPath);

    if (set.isEmpty())
        return PutByIdStatus();
    
    PutByIdStatus result;
    result.m_state = Simple;
    for (unsigned i = 0; i < set.size(); ++i) {
        Structure* structure = set[i];
        
        if (structure->typeInfo().overridesGetOwnPropertySlot() && structure->typeInfo().type() != GlobalObjectType)
            return PutByIdStatus(TakesSlowPath);

        if (!structure->propertyAccessesAreCacheable())
            return PutByIdStatus(TakesSlowPath);
    
        unsigned attributes;
        PropertyOffset offset = structure->getConcurrently(uid, attributes);
        if (isValidOffset(offset)) {
            if (attributes & CustomAccessor)
                return PutByIdStatus(MakesCalls);

            if (attributes & (Accessor | ReadOnly))
                return PutByIdStatus(TakesSlowPath);
            
            WatchpointSet* replaceSet = structure->propertyReplacementWatchpointSet(offset);
            if (!replaceSet || replaceSet->isStillValid()) {
                // When this executes, it'll create, and fire, this replacement watchpoint set.
                // That means that  this has probably never executed or that something fishy is
                // going on. Also, we cannot create or fire the watchpoint set from the concurrent
                // JIT thread, so even if we wanted to do this, we'd need to have a lazy thingy.
                // So, better leave this alone and take slow path.
                return PutByIdStatus(TakesSlowPath);
            }
            
            if (!result.appendVariant(PutByIdVariant::replace(structure, offset)))
                return PutByIdStatus(TakesSlowPath);
            continue;
        }
    
        // Our hypothesis is that we're doing a transition. Before we prove that this is really
        // true, we want to do some sanity checks.
    
        // Don't cache put transitions on dictionaries.
        if (structure->isDictionary())
            return PutByIdStatus(TakesSlowPath);

        // If the structure corresponds to something that isn't an object, then give up, since
        // we don't want to be adding properties to strings.
        if (structure->typeInfo().type() == StringType)
            return PutByIdStatus(TakesSlowPath);
    
        RefPtr<IntendedStructureChain> chain;
        if (!isDirect) {
            chain = adoptRef(new IntendedStructureChain(globalObject, structure));
        
            // If the prototype chain has setters or read-only properties, then give up.
            if (chain->mayInterceptStoreTo(uid))
                return PutByIdStatus(TakesSlowPath);
        
            // If the prototype chain hasn't been normalized (i.e. there are proxies or dictionaries)
            // then give up. The dictionary case would only happen if this structure has not been
            // used in an optimized put_by_id transition. And really the only reason why we would
            // bail here is that I don't really feel like having the optimizing JIT go and flatten
            // dictionaries if we have evidence to suggest that those objects were never used as
            // prototypes in a cacheable prototype access - i.e. there's a good chance that some of
            // the other checks below will fail.
            if (structure->isProxy() || !chain->isNormalized())
                return PutByIdStatus(TakesSlowPath);
        }
    
        // We only optimize if there is already a structure that the transition is cached to.
        Structure* transition = Structure::addPropertyTransitionToExistingStructureConcurrently(structure, uid, 0, offset);
        if (!transition)
            return PutByIdStatus(TakesSlowPath);
        ASSERT(isValidOffset(offset));
    
        bool didAppend = result.appendVariant(
            PutByIdVariant::transition(structure, transition, chain.get(), offset));
        if (!didAppend)
            return PutByIdStatus(TakesSlowPath);
    }
    
    return result;
}
Example #13
0
PutByIdStatus PutByIdStatus::computeForStubInfo(
    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
    StringImpl* uid, CallLinkStatus::ExitSiteData callExitSiteData)
{
    if (!stubInfo || !stubInfo->seen)
        return PutByIdStatus();
    
    switch (stubInfo->accessType) {
    case access_unset:
        // If the JIT saw it but didn't optimize it, then assume that this takes slow path.
        return PutByIdStatus(TakesSlowPath);
        
    case access_put_by_id_replace: {
        PropertyOffset offset =
            stubInfo->u.putByIdReplace.baseObjectStructure->getConcurrently(uid);
        if (isValidOffset(offset)) {
            return PutByIdVariant::replace(
                stubInfo->u.putByIdReplace.baseObjectStructure.get(), offset);
        }
        return PutByIdStatus(TakesSlowPath);
    }
        
    case access_put_by_id_transition_normal:
    case access_put_by_id_transition_direct: {
        ASSERT(stubInfo->u.putByIdTransition.previousStructure->transitionWatchpointSetHasBeenInvalidated());
        PropertyOffset offset = 
            stubInfo->u.putByIdTransition.structure->getConcurrently(uid);
        if (isValidOffset(offset)) {
            RefPtr<IntendedStructureChain> chain;
            if (stubInfo->u.putByIdTransition.chain) {
                chain = adoptRef(new IntendedStructureChain(
                    profiledBlock, stubInfo->u.putByIdTransition.previousStructure.get(),
                    stubInfo->u.putByIdTransition.chain.get()));
            }
            return PutByIdVariant::transition(
                stubInfo->u.putByIdTransition.previousStructure.get(),
                stubInfo->u.putByIdTransition.structure.get(),
                chain.get(), offset);
        }
        return PutByIdStatus(TakesSlowPath);
    }
        
    case access_put_by_id_list: {
        PolymorphicPutByIdList* list = stubInfo->u.putByIdList.list;
        
        PutByIdStatus result;
        result.m_state = Simple;
        
        State slowPathState = TakesSlowPath;
        for (unsigned i = 0; i < list->size(); ++i) {
            const PutByIdAccess& access = list->at(i);
            
            switch (access.type()) {
            case PutByIdAccess::Setter:
            case PutByIdAccess::CustomSetter:
                slowPathState = MakesCalls;
                break;
            default:
                break;
            }
        }
        
        for (unsigned i = 0; i < list->size(); ++i) {
            const PutByIdAccess& access = list->at(i);
            
            PutByIdVariant variant;
            
            switch (access.type()) {
            case PutByIdAccess::Replace: {
                Structure* structure = access.structure();
                PropertyOffset offset = structure->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                variant = PutByIdVariant::replace(structure, offset);
                break;
            }
                
            case PutByIdAccess::Transition: {
                PropertyOffset offset =
                    access.newStructure()->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                RefPtr<IntendedStructureChain> chain;
                if (access.chain()) {
                    chain = adoptRef(new IntendedStructureChain(
                        profiledBlock, access.oldStructure(), access.chain()));
                    if (!chain->isStillValid())
                        continue;
                }
                variant = PutByIdVariant::transition(
                    access.oldStructure(), access.newStructure(), chain.get(), offset);
                break;
            }
                
            case PutByIdAccess::Setter: {
                Structure* structure = access.structure();
                
                ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
                    profiledBlock, structure, access.chain(), access.chainCount(), uid);
                
                switch (complexGetStatus.kind()) {
                case ComplexGetStatus::ShouldSkip:
                    continue;
                    
                case ComplexGetStatus::TakesSlowPath:
                    return PutByIdStatus(slowPathState);
                    
                case ComplexGetStatus::Inlineable: {
                    AccessorCallJITStubRoutine* stub = static_cast<AccessorCallJITStubRoutine*>(
                        access.stubRoutine());
                    std::unique_ptr<CallLinkStatus> callLinkStatus =
                        std::make_unique<CallLinkStatus>(
                            CallLinkStatus::computeFor(
                                locker, profiledBlock, *stub->m_callLinkInfo, callExitSiteData));
                    
                    variant = PutByIdVariant::setter(
                        structure, complexGetStatus.offset(), complexGetStatus.chain(),
                        std::move(callLinkStatus));
                } }
                break;
            }
                
            case PutByIdAccess::CustomSetter:
                return PutByIdStatus(MakesCalls);

            default:
                return PutByIdStatus(slowPathState);
            }
            
            if (!result.appendVariant(variant))
                return PutByIdStatus(slowPathState);
        }
        
        return result;
    }
        
    default:
        return PutByIdStatus(TakesSlowPath);
    }
}
Example #14
0
PutByIdStatus PutByIdStatus::computeFor(JSGlobalObject* globalObject, const StructureSet& set, UniquedStringImpl* uid, bool isDirect)
{
    if (parseIndex(*uid))
        return PutByIdStatus(TakesSlowPath);

    if (set.isEmpty())
        return PutByIdStatus();
    
    PutByIdStatus result;
    result.m_state = Simple;
    for (unsigned i = 0; i < set.size(); ++i) {
        Structure* structure = set[i];
        
        if (structure->typeInfo().overridesGetOwnPropertySlot() && structure->typeInfo().type() != GlobalObjectType)
            return PutByIdStatus(TakesSlowPath);

        if (!structure->propertyAccessesAreCacheable())
            return PutByIdStatus(TakesSlowPath);
    
        unsigned attributes;
        PropertyOffset offset = structure->getConcurrently(uid, attributes);
        if (isValidOffset(offset)) {
            if (attributes & CustomAccessor)
                return PutByIdStatus(MakesCalls);

            if (attributes & (Accessor | ReadOnly))
                return PutByIdStatus(TakesSlowPath);
            
            WatchpointSet* replaceSet = structure->propertyReplacementWatchpointSet(offset);
            if (!replaceSet || replaceSet->isStillValid()) {
                // When this executes, it'll create, and fire, this replacement watchpoint set.
                // That means that  this has probably never executed or that something fishy is
                // going on. Also, we cannot create or fire the watchpoint set from the concurrent
                // JIT thread, so even if we wanted to do this, we'd need to have a lazy thingy.
                // So, better leave this alone and take slow path.
                return PutByIdStatus(TakesSlowPath);
            }

            PutByIdVariant variant =
                PutByIdVariant::replace(structure, offset, structure->inferredTypeDescriptorFor(uid));
            if (!result.appendVariant(variant))
                return PutByIdStatus(TakesSlowPath);
            continue;
        }
    
        // Our hypothesis is that we're doing a transition. Before we prove that this is really
        // true, we want to do some sanity checks.
    
        // Don't cache put transitions on dictionaries.
        if (structure->isDictionary())
            return PutByIdStatus(TakesSlowPath);

        // If the structure corresponds to something that isn't an object, then give up, since
        // we don't want to be adding properties to strings.
        if (!structure->typeInfo().isObject())
            return PutByIdStatus(TakesSlowPath);
    
        ObjectPropertyConditionSet conditionSet;
        if (!isDirect) {
            conditionSet = generateConditionsForPropertySetterMissConcurrently(
                globalObject->vm(), globalObject, structure, uid);
            if (!conditionSet.isValid())
                return PutByIdStatus(TakesSlowPath);
        }
    
        // We only optimize if there is already a structure that the transition is cached to.
        Structure* transition =
            Structure::addPropertyTransitionToExistingStructureConcurrently(structure, uid, 0, offset);
        if (!transition)
            return PutByIdStatus(TakesSlowPath);
        ASSERT(isValidOffset(offset));
    
        bool didAppend = result.appendVariant(
            PutByIdVariant::transition(
                structure, transition, conditionSet, offset,
                transition->inferredTypeDescriptorFor(uid)));
        if (!didAppend)
            return PutByIdStatus(TakesSlowPath);
    }
    
    return result;
}
Example #15
0
PutByIdStatus PutByIdStatus::computeForStubInfo(
    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
    UniquedStringImpl* uid, CallLinkStatus::ExitSiteData callExitSiteData)
{
    if (!stubInfo || !stubInfo->everConsidered)
        return PutByIdStatus();
    
    if (stubInfo->tookSlowPath)
        return PutByIdStatus(TakesSlowPath);
    
    switch (stubInfo->cacheType) {
    case CacheType::Unset:
        // This means that we attempted to cache but failed for some reason.
        return PutByIdStatus(TakesSlowPath);
        
    case CacheType::PutByIdReplace: {
        PropertyOffset offset =
            stubInfo->u.byIdSelf.baseObjectStructure->getConcurrently(uid);
        if (isValidOffset(offset)) {
            return PutByIdVariant::replace(
                stubInfo->u.byIdSelf.baseObjectStructure.get(), offset, InferredType::Top);
        }
        return PutByIdStatus(TakesSlowPath);
    }
        
    case CacheType::Stub: {
        PolymorphicAccess* list = stubInfo->u.stub;
        
        PutByIdStatus result;
        result.m_state = Simple;
        
        State slowPathState = TakesSlowPath;
        for (unsigned i = 0; i < list->size(); ++i) {
            const AccessCase& access = list->at(i);
            if (access.doesCalls())
                slowPathState = MakesCalls;
        }
        
        for (unsigned i = 0; i < list->size(); ++i) {
            const AccessCase& access = list->at(i);
            if (access.viaProxy())
                return PutByIdStatus(slowPathState);
            
            PutByIdVariant variant;
            
            switch (access.type()) {
            case AccessCase::Replace: {
                Structure* structure = access.structure();
                PropertyOffset offset = structure->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                variant = PutByIdVariant::replace(
                    structure, offset, structure->inferredTypeDescriptorFor(uid));
                break;
            }
                
            case AccessCase::Transition: {
                PropertyOffset offset =
                    access.newStructure()->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                ObjectPropertyConditionSet conditionSet = access.conditionSet();
                if (!conditionSet.structuresEnsureValidity())
                    return PutByIdStatus(slowPathState);
                variant = PutByIdVariant::transition(
                    access.structure(), access.newStructure(), conditionSet, offset,
                    access.newStructure()->inferredTypeDescriptorFor(uid));
                break;
            }
                
            case AccessCase::Setter: {
                Structure* structure = access.structure();
                
                ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
                    structure, access.conditionSet(), uid);
                
                switch (complexGetStatus.kind()) {
                case ComplexGetStatus::ShouldSkip:
                    continue;
                    
                case ComplexGetStatus::TakesSlowPath:
                    return PutByIdStatus(slowPathState);
                    
                case ComplexGetStatus::Inlineable: {
                    CallLinkInfo* callLinkInfo = access.callLinkInfo();
                    ASSERT(callLinkInfo);
                    std::unique_ptr<CallLinkStatus> callLinkStatus =
                        std::make_unique<CallLinkStatus>(
                            CallLinkStatus::computeFor(
                                locker, profiledBlock, *callLinkInfo, callExitSiteData));
                    
                    variant = PutByIdVariant::setter(
                        structure, complexGetStatus.offset(), complexGetStatus.conditionSet(),
                        WTFMove(callLinkStatus));
                } }
                break;
            }
                
            case AccessCase::CustomSetter:
                return PutByIdStatus(MakesCalls);

            default:
                return PutByIdStatus(slowPathState);
            }
            
            if (!result.appendVariant(variant))
                return PutByIdStatus(slowPathState);
        }
        
        return result;
    }
        
    default:
        return PutByIdStatus(TakesSlowPath);
    }
}