| /* |
| * Copyright (C) 2014-2016 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 "PolymorphicAccess.h" |
| |
| #if ENABLE(JIT) |
| |
| #include "BinarySwitch.h" |
| #include "CCallHelpers.h" |
| #include "CodeBlock.h" |
| #include "GetterSetter.h" |
| #include "Heap.h" |
| #include "JITOperations.h" |
| #include "JSCInlines.h" |
| #include "LinkBuffer.h" |
| #include "ScratchRegisterAllocator.h" |
| #include "StructureStubClearingWatchpoint.h" |
| #include "StructureStubInfo.h" |
| #include <wtf/CommaPrinter.h> |
| #include <wtf/ListDump.h> |
| |
| namespace JSC { |
| |
| static const bool verbose = false; |
| |
| void AccessGenerationResult::dump(PrintStream& out) const |
| { |
| out.print(m_kind); |
| if (m_code) |
| out.print(":", m_code); |
| } |
| |
| Watchpoint* AccessGenerationState::addWatchpoint(const ObjectPropertyCondition& condition) |
| { |
| return WatchpointsOnStructureStubInfo::ensureReferenceAndAddWatchpoint( |
| watchpoints, jit->codeBlock(), stubInfo, condition); |
| } |
| |
| void AccessGenerationState::restoreScratch() |
| { |
| allocator->restoreReusedRegistersByPopping(*jit, preservedReusedRegisterState); |
| } |
| |
| void AccessGenerationState::succeed() |
| { |
| restoreScratch(); |
| success.append(jit->jump()); |
| } |
| |
| void AccessGenerationState::calculateLiveRegistersForCallAndExceptionHandling() |
| { |
| if (!m_calculatedRegistersForCallAndExceptionHandling) { |
| m_calculatedRegistersForCallAndExceptionHandling = true; |
| |
| m_liveRegistersToPreserveAtExceptionHandlingCallSite = jit->codeBlock()->jitCode()->liveRegistersToPreserveAtExceptionHandlingCallSite(jit->codeBlock(), stubInfo->callSiteIndex); |
| m_needsToRestoreRegistersIfException = m_liveRegistersToPreserveAtExceptionHandlingCallSite.numberOfSetRegisters() > 0; |
| if (m_needsToRestoreRegistersIfException) |
| RELEASE_ASSERT(JITCode::isOptimizingJIT(jit->codeBlock()->jitType())); |
| |
| m_liveRegistersForCall = RegisterSet(m_liveRegistersToPreserveAtExceptionHandlingCallSite, allocator->usedRegisters()); |
| m_liveRegistersForCall.exclude(RegisterSet::registersToNotSaveForJSCall()); |
| } |
| } |
| |
| void AccessGenerationState::preserveLiveRegistersToStackForCall() |
| { |
| unsigned extraStackPadding = 0; |
| unsigned numberOfStackBytesUsedForRegisterPreservation = ScratchRegisterAllocator::preserveRegistersToStackForCall(*jit, liveRegistersForCall(), extraStackPadding); |
| if (m_numberOfStackBytesUsedForRegisterPreservation != std::numeric_limits<unsigned>::max()) |
| RELEASE_ASSERT(numberOfStackBytesUsedForRegisterPreservation == m_numberOfStackBytesUsedForRegisterPreservation); |
| m_numberOfStackBytesUsedForRegisterPreservation = numberOfStackBytesUsedForRegisterPreservation; |
| } |
| |
| void AccessGenerationState::restoreLiveRegistersFromStackForCall(bool isGetter) |
| { |
| RegisterSet dontRestore; |
| if (isGetter) { |
| // This is the result value. We don't want to overwrite the result with what we stored to the stack. |
| // We sometimes have to store it to the stack just in case we throw an exception and need the original value. |
| dontRestore.set(valueRegs); |
| } |
| restoreLiveRegistersFromStackForCall(dontRestore); |
| } |
| |
| void AccessGenerationState::restoreLiveRegistersFromStackForCallWithThrownException() |
| { |
| // Even if we're a getter, we don't want to ignore the result value like we normally do |
| // because the getter threw, and therefore, didn't return a value that means anything. |
| // Instead, we want to restore that register to what it was upon entering the getter |
| // inline cache. The subtlety here is if the base and the result are the same register, |
| // and the getter threw, we want OSR exit to see the original base value, not the result |
| // of the getter call. |
| RegisterSet dontRestore = liveRegistersForCall(); |
| // As an optimization here, we only need to restore what is live for exception handling. |
| // We can construct the dontRestore set to accomplish this goal by having it contain only |
| // what is live for call but not live for exception handling. By ignoring things that are |
| // only live at the call but not the exception handler, we will only restore things live |
| // at the exception handler. |
| dontRestore.exclude(liveRegistersToPreserveAtExceptionHandlingCallSite()); |
| restoreLiveRegistersFromStackForCall(dontRestore); |
| } |
| |
| void AccessGenerationState::restoreLiveRegistersFromStackForCall(const RegisterSet& dontRestore) |
| { |
| unsigned extraStackPadding = 0; |
| ScratchRegisterAllocator::restoreRegistersFromStackForCall(*jit, liveRegistersForCall(), dontRestore, m_numberOfStackBytesUsedForRegisterPreservation, extraStackPadding); |
| } |
| |
| CallSiteIndex AccessGenerationState::callSiteIndexForExceptionHandlingOrOriginal() |
| { |
| RELEASE_ASSERT(m_calculatedRegistersForCallAndExceptionHandling); |
| |
| if (!m_calculatedCallSiteIndex) { |
| m_calculatedCallSiteIndex = true; |
| |
| if (m_needsToRestoreRegistersIfException) |
| m_callSiteIndex = jit->codeBlock()->newExceptionHandlingCallSiteIndex(stubInfo->callSiteIndex); |
| else |
| m_callSiteIndex = originalCallSiteIndex(); |
| } |
| |
| return m_callSiteIndex; |
| } |
| |
| const HandlerInfo& AccessGenerationState::originalExceptionHandler() const |
| { |
| RELEASE_ASSERT(m_needsToRestoreRegistersIfException); |
| HandlerInfo* exceptionHandler = jit->codeBlock()->handlerForIndex(stubInfo->callSiteIndex.bits()); |
| RELEASE_ASSERT(exceptionHandler); |
| return *exceptionHandler; |
| } |
| |
| CallSiteIndex AccessGenerationState::originalCallSiteIndex() const { return stubInfo->callSiteIndex; } |
| |
| AccessCase::AccessCase() |
| { |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::tryGet( |
| VM& vm, JSCell* owner, AccessType type, PropertyOffset offset, Structure* structure, |
| const ObjectPropertyConditionSet& conditionSet, bool viaProxy, WatchpointSet* additionalSet) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = type; |
| result->m_offset = offset; |
| result->m_structure.set(vm, owner, structure); |
| result->m_conditionSet = conditionSet; |
| |
| if (viaProxy || additionalSet) { |
| result->m_rareData = std::make_unique<RareData>(); |
| result->m_rareData->viaProxy = viaProxy; |
| result->m_rareData->additionalSet = additionalSet; |
| } |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::get( |
| VM& vm, JSCell* owner, AccessType type, PropertyOffset offset, Structure* structure, |
| const ObjectPropertyConditionSet& conditionSet, bool viaProxy, WatchpointSet* additionalSet, |
| PropertySlot::GetValueFunc customGetter, JSObject* customSlotBase) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = type; |
| result->m_offset = offset; |
| result->m_structure.set(vm, owner, structure); |
| result->m_conditionSet = conditionSet; |
| |
| if (viaProxy || additionalSet || result->doesCalls() || customGetter || customSlotBase) { |
| result->m_rareData = std::make_unique<RareData>(); |
| result->m_rareData->viaProxy = viaProxy; |
| result->m_rareData->additionalSet = additionalSet; |
| result->m_rareData->customAccessor.getter = customGetter; |
| result->m_rareData->customSlotBase.setMayBeNull(vm, owner, customSlotBase); |
| } |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::megamorphicLoad(VM& vm, JSCell* owner) |
| { |
| UNUSED_PARAM(vm); |
| UNUSED_PARAM(owner); |
| |
| if (GPRInfo::numberOfRegisters < 9) |
| return nullptr; |
| |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = MegamorphicLoad; |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::replace( |
| VM& vm, JSCell* owner, Structure* structure, PropertyOffset offset) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = Replace; |
| result->m_offset = offset; |
| result->m_structure.set(vm, owner, structure); |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::transition( |
| VM& vm, JSCell* owner, Structure* oldStructure, Structure* newStructure, PropertyOffset offset, |
| const ObjectPropertyConditionSet& conditionSet) |
| { |
| RELEASE_ASSERT(oldStructure == newStructure->previousID()); |
| |
| // Skip optimizing the case where we need a realloc, if we don't have |
| // enough registers to make it happen. |
| if (GPRInfo::numberOfRegisters < 6 |
| && oldStructure->outOfLineCapacity() != newStructure->outOfLineCapacity() |
| && oldStructure->outOfLineCapacity()) { |
| return nullptr; |
| } |
| |
| // Skip optimizing the case where we need realloc, and the structure has |
| // indexing storage. |
| // FIXME: We shouldn't skip this! Implement it! |
| // https://bugs.webkit.org/show_bug.cgi?id=130914 |
| if (oldStructure->couldHaveIndexingHeader()) |
| return nullptr; |
| |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = Transition; |
| result->m_offset = offset; |
| result->m_structure.set(vm, owner, newStructure); |
| result->m_conditionSet = conditionSet; |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::setter( |
| VM& vm, JSCell* owner, AccessType type, Structure* structure, PropertyOffset offset, |
| const ObjectPropertyConditionSet& conditionSet, PutPropertySlot::PutValueFunc customSetter, |
| JSObject* customSlotBase) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = type; |
| result->m_offset = offset; |
| result->m_structure.set(vm, owner, structure); |
| result->m_conditionSet = conditionSet; |
| result->m_rareData = std::make_unique<RareData>(); |
| result->m_rareData->customAccessor.setter = customSetter; |
| result->m_rareData->customSlotBase.setMayBeNull(vm, owner, customSlotBase); |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::in( |
| VM& vm, JSCell* owner, AccessType type, Structure* structure, |
| const ObjectPropertyConditionSet& conditionSet) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = type; |
| result->m_structure.set(vm, owner, structure); |
| result->m_conditionSet = conditionSet; |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::getLength(VM&, JSCell*, AccessType type) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = type; |
| |
| return result; |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::getIntrinsic( |
| VM& vm, JSCell* owner, JSFunction* getter, PropertyOffset offset, |
| Structure* structure, const ObjectPropertyConditionSet& conditionSet) |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| |
| result->m_type = IntrinsicGetter; |
| result->m_structure.set(vm, owner, structure); |
| result->m_conditionSet = conditionSet; |
| result->m_offset = offset; |
| |
| result->m_rareData = std::make_unique<RareData>(); |
| result->m_rareData->intrinsicFunction.set(vm, owner, getter); |
| |
| return result; |
| } |
| |
| AccessCase::~AccessCase() |
| { |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::fromStructureStubInfo( |
| VM& vm, JSCell* owner, StructureStubInfo& stubInfo) |
| { |
| switch (stubInfo.cacheType) { |
| case CacheType::GetByIdSelf: |
| return get( |
| vm, owner, Load, stubInfo.u.byIdSelf.offset, |
| stubInfo.u.byIdSelf.baseObjectStructure.get()); |
| |
| case CacheType::PutByIdReplace: |
| return replace( |
| vm, owner, stubInfo.u.byIdSelf.baseObjectStructure.get(), stubInfo.u.byIdSelf.offset); |
| |
| default: |
| return nullptr; |
| } |
| } |
| |
| std::unique_ptr<AccessCase> AccessCase::clone() const |
| { |
| std::unique_ptr<AccessCase> result(new AccessCase()); |
| result->m_type = m_type; |
| result->m_offset = m_offset; |
| result->m_structure = m_structure; |
| result->m_conditionSet = m_conditionSet; |
| if (RareData* rareData = m_rareData.get()) { |
| result->m_rareData = std::make_unique<RareData>(); |
| result->m_rareData->viaProxy = rareData->viaProxy; |
| result->m_rareData->additionalSet = rareData->additionalSet; |
| // NOTE: We don't copy the callLinkInfo, since that's created during code generation. |
| result->m_rareData->customAccessor.opaque = rareData->customAccessor.opaque; |
| result->m_rareData->customSlotBase = rareData->customSlotBase; |
| result->m_rareData->intrinsicFunction = rareData->intrinsicFunction; |
| } |
| return result; |
| } |
| |
| bool AccessCase::guardedByStructureCheck() const |
| { |
| if (viaProxy()) |
| return false; |
| |
| switch (m_type) { |
| case MegamorphicLoad: |
| case ArrayLength: |
| case StringLength: |
| return false; |
| default: |
| return true; |
| } |
| } |
| |
| JSObject* AccessCase::alternateBase() const |
| { |
| if (customSlotBase()) |
| return customSlotBase(); |
| return conditionSet().slotBaseCondition().object(); |
| } |
| |
| bool AccessCase::couldStillSucceed() const |
| { |
| return m_conditionSet.structuresEnsureValidityAssumingImpurePropertyWatchpoint(); |
| } |
| |
| bool AccessCase::canBeReplacedByMegamorphicLoad() const |
| { |
| return type() == Load |
| && !viaProxy() |
| && conditionSet().isEmpty() |
| && !additionalSet() |
| && !customSlotBase(); |
| } |
| |
| bool AccessCase::canReplace(const AccessCase& other) const |
| { |
| // We could do a lot better here, but for now we just do something obvious. |
| |
| if (type() == MegamorphicLoad && other.canBeReplacedByMegamorphicLoad()) |
| return true; |
| |
| if (!guardedByStructureCheck() || !other.guardedByStructureCheck()) { |
| // FIXME: Implement this! |
| return false; |
| } |
| |
| return structure() == other.structure(); |
| } |
| |
| void AccessCase::dump(PrintStream& out) const |
| { |
| out.print(m_type, ":("); |
| |
| CommaPrinter comma; |
| |
| if (m_type == Transition) |
| out.print(comma, "structure = ", pointerDump(structure()), " -> ", pointerDump(newStructure())); |
| else if (m_structure) |
| out.print(comma, "structure = ", pointerDump(m_structure.get())); |
| |
| if (isValidOffset(m_offset)) |
| out.print(comma, "offset = ", m_offset); |
| if (!m_conditionSet.isEmpty()) |
| out.print(comma, "conditions = ", m_conditionSet); |
| |
| if (RareData* rareData = m_rareData.get()) { |
| if (rareData->viaProxy) |
| out.print(comma, "viaProxy = ", rareData->viaProxy); |
| if (rareData->additionalSet) |
| out.print(comma, "additionalSet = ", RawPointer(rareData->additionalSet.get())); |
| if (rareData->callLinkInfo) |
| out.print(comma, "callLinkInfo = ", RawPointer(rareData->callLinkInfo.get())); |
| if (rareData->customAccessor.opaque) |
| out.print(comma, "customAccessor = ", RawPointer(rareData->customAccessor.opaque)); |
| if (rareData->customSlotBase) |
| out.print(comma, "customSlotBase = ", RawPointer(rareData->customSlotBase.get())); |
| } |
| |
| out.print(")"); |
| } |
| |
| bool AccessCase::visitWeak(VM& vm) const |
| { |
| if (m_structure && !Heap::isMarked(m_structure.get())) |
| return false; |
| if (!m_conditionSet.areStillLive()) |
| return false; |
| if (m_rareData) { |
| if (m_rareData->callLinkInfo) |
| m_rareData->callLinkInfo->visitWeak(vm); |
| if (m_rareData->customSlotBase && !Heap::isMarked(m_rareData->customSlotBase.get())) |
| return false; |
| if (m_rareData->intrinsicFunction && !Heap::isMarked(m_rareData->intrinsicFunction.get())) |
| return false; |
| } |
| return true; |
| } |
| |
| void AccessCase::generateWithGuard( |
| AccessGenerationState& state, CCallHelpers::JumpList& fallThrough) |
| { |
| CCallHelpers& jit = *state.jit; |
| VM& vm = *jit.vm(); |
| const Identifier& ident = *state.ident; |
| StructureStubInfo& stubInfo = *state.stubInfo; |
| JSValueRegs valueRegs = state.valueRegs; |
| GPRReg baseGPR = state.baseGPR; |
| GPRReg scratchGPR = state.scratchGPR; |
| |
| UNUSED_PARAM(vm); |
| |
| switch (m_type) { |
| case ArrayLength: { |
| ASSERT(!viaProxy()); |
| jit.load8(CCallHelpers::Address(baseGPR, JSCell::indexingTypeOffset()), scratchGPR); |
| fallThrough.append( |
| jit.branchTest32( |
| CCallHelpers::Zero, scratchGPR, CCallHelpers::TrustedImm32(IsArray))); |
| fallThrough.append( |
| jit.branchTest32( |
| CCallHelpers::Zero, scratchGPR, CCallHelpers::TrustedImm32(IndexingShapeMask))); |
| break; |
| } |
| |
| case StringLength: { |
| ASSERT(!viaProxy()); |
| fallThrough.append( |
| jit.branch8( |
| CCallHelpers::NotEqual, |
| CCallHelpers::Address(baseGPR, JSCell::typeInfoTypeOffset()), |
| CCallHelpers::TrustedImm32(StringType))); |
| break; |
| } |
| |
| case MegamorphicLoad: { |
| UniquedStringImpl* key = ident.impl(); |
| unsigned hash = IdentifierRepHash::hash(key); |
| |
| ScratchRegisterAllocator allocator(stubInfo.patch.usedRegisters); |
| allocator.lock(baseGPR); |
| #if USE(JSVALUE32_64) |
| allocator.lock(static_cast<GPRReg>(stubInfo.patch.baseTagGPR)); |
| #endif |
| allocator.lock(valueRegs); |
| allocator.lock(scratchGPR); |
| |
| GPRReg intermediateGPR = scratchGPR; |
| GPRReg maskGPR = allocator.allocateScratchGPR(); |
| GPRReg maskedHashGPR = allocator.allocateScratchGPR(); |
| GPRReg indexGPR = allocator.allocateScratchGPR(); |
| GPRReg offsetGPR = allocator.allocateScratchGPR(); |
| |
| if (verbose) { |
| dataLog("baseGPR = ", baseGPR, "\n"); |
| dataLog("valueRegs = ", valueRegs, "\n"); |
| dataLog("scratchGPR = ", scratchGPR, "\n"); |
| dataLog("intermediateGPR = ", intermediateGPR, "\n"); |
| dataLog("maskGPR = ", maskGPR, "\n"); |
| dataLog("maskedHashGPR = ", maskedHashGPR, "\n"); |
| dataLog("indexGPR = ", indexGPR, "\n"); |
| dataLog("offsetGPR = ", offsetGPR, "\n"); |
| } |
| |
| ScratchRegisterAllocator::PreservedState preservedState = |
| allocator.preserveReusedRegistersByPushing(jit, ScratchRegisterAllocator::ExtraStackSpace::SpaceForCCall); |
| |
| CCallHelpers::JumpList myFailAndIgnore; |
| CCallHelpers::JumpList myFallThrough; |
| |
| jit.emitLoadStructure(baseGPR, intermediateGPR, maskGPR); |
| jit.loadPtr( |
| CCallHelpers::Address(intermediateGPR, Structure::propertyTableUnsafeOffset()), |
| intermediateGPR); |
| |
| myFailAndIgnore.append(jit.branchTestPtr(CCallHelpers::Zero, intermediateGPR)); |
| |
| jit.load32(CCallHelpers::Address(intermediateGPR, PropertyTable::offsetOfIndexMask()), maskGPR); |
| jit.loadPtr(CCallHelpers::Address(intermediateGPR, PropertyTable::offsetOfIndex()), indexGPR); |
| jit.load32( |
| CCallHelpers::Address(intermediateGPR, PropertyTable::offsetOfIndexSize()), |
| intermediateGPR); |
| |
| jit.move(maskGPR, maskedHashGPR); |
| jit.and32(CCallHelpers::TrustedImm32(hash), maskedHashGPR); |
| jit.lshift32(CCallHelpers::TrustedImm32(2), intermediateGPR); |
| jit.addPtr(indexGPR, intermediateGPR); |
| |
| CCallHelpers::Label loop = jit.label(); |
| |
| jit.load32(CCallHelpers::BaseIndex(indexGPR, maskedHashGPR, CCallHelpers::TimesFour), offsetGPR); |
| |
| myFallThrough.append( |
| jit.branch32( |
| CCallHelpers::Equal, |
| offsetGPR, |
| CCallHelpers::TrustedImm32(PropertyTable::EmptyEntryIndex))); |
| |
| jit.sub32(CCallHelpers::TrustedImm32(1), offsetGPR); |
| jit.mul32(CCallHelpers::TrustedImm32(sizeof(PropertyMapEntry)), offsetGPR, offsetGPR); |
| jit.addPtr(intermediateGPR, offsetGPR); |
| |
| CCallHelpers::Jump collision = jit.branchPtr( |
| CCallHelpers::NotEqual, |
| CCallHelpers::Address(offsetGPR, OBJECT_OFFSETOF(PropertyMapEntry, key)), |
| CCallHelpers::TrustedImmPtr(key)); |
| |
| // offsetGPR currently holds a pointer to the PropertyMapEntry, which has the offset and attributes. |
| // Check them and then attempt the load. |
| |
| myFallThrough.append( |
| jit.branchTest32( |
| CCallHelpers::NonZero, |
| CCallHelpers::Address(offsetGPR, OBJECT_OFFSETOF(PropertyMapEntry, attributes)), |
| CCallHelpers::TrustedImm32(Accessor | CustomAccessor))); |
| |
| jit.load32(CCallHelpers::Address(offsetGPR, OBJECT_OFFSETOF(PropertyMapEntry, offset)), offsetGPR); |
| |
| jit.loadProperty(baseGPR, offsetGPR, valueRegs); |
| |
| allocator.restoreReusedRegistersByPopping(jit, preservedState); |
| state.succeed(); |
| |
| collision.link(&jit); |
| |
| jit.add32(CCallHelpers::TrustedImm32(1), maskedHashGPR); |
| |
| // FIXME: We could be smarter about this. Currently we're burning a GPR for the mask. But looping |
| // around isn't super common so we could, for example, recompute the mask from the difference between |
| // the table and index. But before we do that we should probably make it easier to multiply and |
| // divide by the size of PropertyMapEntry. That probably involves making PropertyMapEntry be arranged |
| // to have a power-of-2 size. |
| jit.and32(maskGPR, maskedHashGPR); |
| jit.jump().linkTo(loop, &jit); |
| |
| if (allocator.didReuseRegisters()) { |
| myFailAndIgnore.link(&jit); |
| allocator.restoreReusedRegistersByPopping(jit, preservedState); |
| state.failAndIgnore.append(jit.jump()); |
| |
| myFallThrough.link(&jit); |
| allocator.restoreReusedRegistersByPopping(jit, preservedState); |
| fallThrough.append(jit.jump()); |
| } else { |
| state.failAndIgnore.append(myFailAndIgnore); |
| fallThrough.append(myFallThrough); |
| } |
| return; |
| } |
| |
| default: { |
| if (viaProxy()) { |
| fallThrough.append( |
| jit.branch8( |
| CCallHelpers::NotEqual, |
| CCallHelpers::Address(baseGPR, JSCell::typeInfoTypeOffset()), |
| CCallHelpers::TrustedImm32(PureForwardingProxyType))); |
| |
| jit.loadPtr(CCallHelpers::Address(baseGPR, JSProxy::targetOffset()), scratchGPR); |
| |
| fallThrough.append( |
| jit.branchStructure( |
| CCallHelpers::NotEqual, |
| CCallHelpers::Address(scratchGPR, JSCell::structureIDOffset()), |
| structure())); |
| } else { |
| fallThrough.append( |
| jit.branchStructure( |
| CCallHelpers::NotEqual, |
| CCallHelpers::Address(baseGPR, JSCell::structureIDOffset()), |
| structure())); |
| } |
| break; |
| } }; |
| |
| generate(state); |
| } |
| |
| // EncodedJSValue in JSVALUE32_64 is a 64-bit integer. When being compiled in ARM EABI, it must be aligned on an even-numbered register (r0, r2 or [sp]). |
| // To prevent the assembler from using wrong registers, let's occupy r1 or r3 with a dummy argument when necessary. |
| #if (COMPILER_SUPPORTS(EABI) && CPU(ARM)) || CPU(MIPS) |
| #define EABI_32BIT_DUMMY_ARG CCallHelpers::TrustedImm32(0), |
| #else |
| #define EABI_32BIT_DUMMY_ARG |
| #endif |
| |
| void AccessCase::generate(AccessGenerationState& state) |
| { |
| if (verbose) |
| dataLog("Generating code for: ", *this, "\n"); |
| |
| CCallHelpers& jit = *state.jit; |
| VM& vm = *jit.vm(); |
| CodeBlock* codeBlock = jit.codeBlock(); |
| StructureStubInfo& stubInfo = *state.stubInfo; |
| const Identifier& ident = *state.ident; |
| JSValueRegs valueRegs = state.valueRegs; |
| GPRReg baseGPR = state.baseGPR; |
| GPRReg scratchGPR = state.scratchGPR; |
| |
| ASSERT(m_conditionSet.structuresEnsureValidityAssumingImpurePropertyWatchpoint()); |
| |
| if ((structure() && structure()->needImpurePropertyWatchpoint()) |
| || m_conditionSet.needImpurePropertyWatchpoint()) |
| vm.registerWatchpointForImpureProperty(ident, state.addWatchpoint()); |
| |
| if (additionalSet()) |
| additionalSet()->add(state.addWatchpoint()); |
| |
| for (const ObjectPropertyCondition& condition : m_conditionSet) { |
| Structure* structure = condition.object()->structure(); |
| |
| if (condition.isWatchableAssumingImpurePropertyWatchpoint()) { |
| structure->addTransitionWatchpoint(state.addWatchpoint(condition)); |
| continue; |
| } |
| |
| if (!condition.structureEnsuresValidityAssumingImpurePropertyWatchpoint(structure)) { |
| dataLog("This condition is no longer met: ", condition, "\n"); |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| // We will emit code that has a weak reference that isn't otherwise listed anywhere. |
| state.weakReferences.append(WriteBarrier<JSCell>(vm, codeBlock, structure)); |
| |
| jit.move(CCallHelpers::TrustedImmPtr(condition.object()), scratchGPR); |
| state.failAndRepatch.append( |
| jit.branchStructure( |
| CCallHelpers::NotEqual, |
| CCallHelpers::Address(scratchGPR, JSCell::structureIDOffset()), |
| structure)); |
| } |
| |
| switch (m_type) { |
| case InHit: |
| case InMiss: |
| jit.boxBooleanPayload(m_type == InHit, valueRegs.payloadGPR()); |
| state.succeed(); |
| return; |
| |
| case Miss: |
| jit.moveTrustedValue(jsUndefined(), valueRegs); |
| state.succeed(); |
| return; |
| |
| case Load: |
| case GetGetter: |
| case Getter: |
| case Setter: |
| case CustomValueGetter: |
| case CustomAccessorGetter: |
| case CustomValueSetter: |
| case CustomAccessorSetter: { |
| if (isValidOffset(m_offset)) { |
| Structure* currStructure; |
| if (m_conditionSet.isEmpty()) |
| currStructure = structure(); |
| else |
| currStructure = m_conditionSet.slotBaseCondition().object()->structure(); |
| currStructure->startWatchingPropertyForReplacements(vm, offset()); |
| } |
| |
| GPRReg baseForGetGPR; |
| if (viaProxy()) { |
| baseForGetGPR = valueRegs.payloadGPR(); |
| jit.loadPtr( |
| CCallHelpers::Address(baseGPR, JSProxy::targetOffset()), |
| baseForGetGPR); |
| } else |
| baseForGetGPR = baseGPR; |
| |
| GPRReg baseForAccessGPR; |
| if (!m_conditionSet.isEmpty()) { |
| jit.move( |
| CCallHelpers::TrustedImmPtr(alternateBase()), |
| scratchGPR); |
| baseForAccessGPR = scratchGPR; |
| } else |
| baseForAccessGPR = baseForGetGPR; |
| |
| GPRReg loadedValueGPR = InvalidGPRReg; |
| if (m_type != CustomValueGetter && m_type != CustomAccessorGetter && m_type != CustomValueSetter && m_type != CustomAccessorSetter) { |
| if (m_type == Load || m_type == GetGetter) |
| loadedValueGPR = valueRegs.payloadGPR(); |
| else |
| loadedValueGPR = scratchGPR; |
| |
| GPRReg storageGPR; |
| if (isInlineOffset(m_offset)) |
| storageGPR = baseForAccessGPR; |
| else { |
| jit.loadPtr( |
| CCallHelpers::Address(baseForAccessGPR, JSObject::butterflyOffset()), |
| loadedValueGPR); |
| storageGPR = loadedValueGPR; |
| } |
| |
| #if USE(JSVALUE64) |
| jit.load64( |
| CCallHelpers::Address(storageGPR, offsetRelativeToBase(m_offset)), loadedValueGPR); |
| #else |
| if (m_type == Load || m_type == GetGetter) { |
| jit.load32( |
| CCallHelpers::Address(storageGPR, offsetRelativeToBase(m_offset) + TagOffset), |
| valueRegs.tagGPR()); |
| } |
| jit.load32( |
| CCallHelpers::Address(storageGPR, offsetRelativeToBase(m_offset) + PayloadOffset), |
| loadedValueGPR); |
| #endif |
| } |
| |
| if (m_type == Load || m_type == GetGetter) { |
| state.succeed(); |
| return; |
| } |
| |
| // Stuff for custom getters/setters. |
| CCallHelpers::Call operationCall; |
| CCallHelpers::Call lookupExceptionHandlerCall; |
| |
| // Stuff for JS getters/setters. |
| CCallHelpers::DataLabelPtr addressOfLinkFunctionCheck; |
| CCallHelpers::Call fastPathCall; |
| CCallHelpers::Call slowPathCall; |
| |
| CCallHelpers::Jump success; |
| CCallHelpers::Jump fail; |
| |
| // This also does the necessary calculations of whether or not we're an |
| // exception handling call site. |
| state.calculateLiveRegistersForCallAndExceptionHandling(); |
| state.preserveLiveRegistersToStackForCall(); |
| |
| // Need to make sure that whenever this call is made in the future, we remember the |
| // place that we made it from. |
| jit.store32( |
| CCallHelpers::TrustedImm32(state.callSiteIndexForExceptionHandlingOrOriginal().bits()), |
| CCallHelpers::tagFor(static_cast<VirtualRegister>(JSStack::ArgumentCount))); |
| |
| if (m_type == Getter || m_type == Setter) { |
| // Create a JS call using a JS call inline cache. Assume that: |
| // |
| // - SP is aligned and represents the extent of the calling compiler's stack usage. |
| // |
| // - FP is set correctly (i.e. it points to the caller's call frame header). |
| // |
| // - SP - FP is an aligned difference. |
| // |
| // - Any byte between FP (exclusive) and SP (inclusive) could be live in the calling |
| // code. |
| // |
| // Therefore, we temporarily grow the stack for the purpose of the call and then |
| // shrink it after. |
| |
| RELEASE_ASSERT(!m_rareData->callLinkInfo); |
| m_rareData->callLinkInfo = std::make_unique<CallLinkInfo>(); |
| |
| // FIXME: If we generated a polymorphic call stub that jumped back to the getter |
| // stub, which then jumped back to the main code, then we'd have a reachability |
| // situation that the GC doesn't know about. The GC would ensure that the polymorphic |
| // call stub stayed alive, and it would ensure that the main code stayed alive, but |
| // it wouldn't know that the getter stub was alive. Ideally JIT stub routines would |
| // be GC objects, and then we'd be able to say that the polymorphic call stub has a |
| // reference to the getter stub. |
| // https://bugs.webkit.org/show_bug.cgi?id=148914 |
| m_rareData->callLinkInfo->disallowStubs(); |
| |
| m_rareData->callLinkInfo->setUpCall( |
| CallLinkInfo::Call, stubInfo.codeOrigin, loadedValueGPR); |
| |
| CCallHelpers::JumpList done; |
| |
| // There is a "this" argument. |
| unsigned numberOfParameters = 1; |
| // ... and a value argument if we're calling a setter. |
| if (m_type == Setter) |
| numberOfParameters++; |
| |
| // Get the accessor; if there ain't one then the result is jsUndefined(). |
| if (m_type == Setter) { |
| jit.loadPtr( |
| CCallHelpers::Address(loadedValueGPR, GetterSetter::offsetOfSetter()), |
| loadedValueGPR); |
| } else { |
| jit.loadPtr( |
| CCallHelpers::Address(loadedValueGPR, GetterSetter::offsetOfGetter()), |
| loadedValueGPR); |
| } |
| |
| CCallHelpers::Jump returnUndefined = jit.branchTestPtr( |
| CCallHelpers::Zero, loadedValueGPR); |
| |
| unsigned numberOfRegsForCall = JSStack::CallFrameHeaderSize + numberOfParameters; |
| |
| unsigned numberOfBytesForCall = |
| numberOfRegsForCall * sizeof(Register) + sizeof(CallerFrameAndPC); |
| |
| unsigned alignedNumberOfBytesForCall = |
| WTF::roundUpToMultipleOf(stackAlignmentBytes(), numberOfBytesForCall); |
| |
| jit.subPtr( |
| CCallHelpers::TrustedImm32(alignedNumberOfBytesForCall), |
| CCallHelpers::stackPointerRegister); |
| |
| CCallHelpers::Address calleeFrame = CCallHelpers::Address( |
| CCallHelpers::stackPointerRegister, |
| -static_cast<ptrdiff_t>(sizeof(CallerFrameAndPC))); |
| |
| jit.store32( |
| CCallHelpers::TrustedImm32(numberOfParameters), |
| calleeFrame.withOffset(JSStack::ArgumentCount * sizeof(Register) + PayloadOffset)); |
| |
| jit.storeCell( |
| loadedValueGPR, calleeFrame.withOffset(JSStack::Callee * sizeof(Register))); |
| |
| jit.storeCell( |
| baseForGetGPR, |
| calleeFrame.withOffset(virtualRegisterForArgument(0).offset() * sizeof(Register))); |
| |
| if (m_type == Setter) { |
| jit.storeValue( |
| valueRegs, |
| calleeFrame.withOffset( |
| virtualRegisterForArgument(1).offset() * sizeof(Register))); |
| } |
| |
| CCallHelpers::Jump slowCase = jit.branchPtrWithPatch( |
| CCallHelpers::NotEqual, loadedValueGPR, addressOfLinkFunctionCheck, |
| CCallHelpers::TrustedImmPtr(0)); |
| |
| fastPathCall = jit.nearCall(); |
| if (m_type == Getter) |
| jit.setupResults(valueRegs); |
| done.append(jit.jump()); |
| |
| slowCase.link(&jit); |
| jit.move(loadedValueGPR, GPRInfo::regT0); |
| #if USE(JSVALUE32_64) |
| // We *always* know that the getter/setter, if non-null, is a cell. |
| jit.move(CCallHelpers::TrustedImm32(JSValue::CellTag), GPRInfo::regT1); |
| #endif |
| jit.move(CCallHelpers::TrustedImmPtr(m_rareData->callLinkInfo.get()), GPRInfo::regT2); |
| slowPathCall = jit.nearCall(); |
| if (m_type == Getter) |
| jit.setupResults(valueRegs); |
| done.append(jit.jump()); |
| |
| returnUndefined.link(&jit); |
| if (m_type == Getter) |
| jit.moveTrustedValue(jsUndefined(), valueRegs); |
| |
| done.link(&jit); |
| |
| jit.addPtr(CCallHelpers::TrustedImm32((jit.codeBlock()->stackPointerOffset() * sizeof(Register)) - state.preservedReusedRegisterState.numberOfBytesPreserved - state.numberOfStackBytesUsedForRegisterPreservation()), |
| GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister); |
| state.restoreLiveRegistersFromStackForCall(isGetter()); |
| |
| state.callbacks.append( |
| [=, &vm] (LinkBuffer& linkBuffer) { |
| m_rareData->callLinkInfo->setCallLocations( |
| linkBuffer.locationOfNearCall(slowPathCall), |
| linkBuffer.locationOf(addressOfLinkFunctionCheck), |
| linkBuffer.locationOfNearCall(fastPathCall)); |
| |
| linkBuffer.link( |
| slowPathCall, |
| CodeLocationLabel(vm.getCTIStub(linkCallThunkGenerator).code())); |
| }); |
| } else { |
| // Need to make room for the C call so any of our stack spillage isn't overwritten. |
| // We also need to make room because we may be an inline cache in the FTL and not |
| // have a JIT call frame. |
| bool needsToMakeRoomOnStackForCCall = state.numberOfStackBytesUsedForRegisterPreservation() || codeBlock->jitType() == JITCode::FTLJIT; |
| if (needsToMakeRoomOnStackForCCall) |
| jit.makeSpaceOnStackForCCall(); |
| |
| // getter: EncodedJSValue (*GetValueFunc)(ExecState*, EncodedJSValue thisValue, PropertyName); |
| // setter: void (*PutValueFunc)(ExecState*, EncodedJSValue thisObject, EncodedJSValue value); |
| // Custom values are passed the slotBase (the property holder), custom accessors are passed the thisVaule (reciever). |
| GPRReg baseForCustomValue = m_type == CustomValueGetter || m_type == CustomValueSetter ? baseForAccessGPR : baseForGetGPR; |
| #if USE(JSVALUE64) |
| if (m_type == CustomValueGetter || m_type == CustomAccessorGetter) { |
| jit.setupArgumentsWithExecState( |
| baseForCustomValue, |
| CCallHelpers::TrustedImmPtr(ident.impl())); |
| } else |
| jit.setupArgumentsWithExecState(baseForCustomValue, valueRegs.gpr()); |
| #else |
| if (m_type == CustomValueGetter || m_type == CustomAccessorGetter) { |
| jit.setupArgumentsWithExecState( |
| EABI_32BIT_DUMMY_ARG baseForCustomValue, |
| CCallHelpers::TrustedImm32(JSValue::CellTag), |
| CCallHelpers::TrustedImmPtr(ident.impl())); |
| } else { |
| jit.setupArgumentsWithExecState( |
| EABI_32BIT_DUMMY_ARG baseForCustomValue, |
| CCallHelpers::TrustedImm32(JSValue::CellTag), |
| valueRegs.payloadGPR(), valueRegs.tagGPR()); |
| } |
| #endif |
| jit.storePtr(GPRInfo::callFrameRegister, &vm.topCallFrame); |
| |
| operationCall = jit.call(); |
| if (m_type == CustomValueGetter || m_type == CustomAccessorGetter) |
| jit.setupResults(valueRegs); |
| if (needsToMakeRoomOnStackForCCall) |
| jit.reclaimSpaceOnStackForCCall(); |
| |
| CCallHelpers::Jump noException = |
| jit.emitExceptionCheck(CCallHelpers::InvertedExceptionCheck); |
| |
| bool didSetLookupExceptionHandler = false; |
| state.restoreLiveRegistersFromStackForCallWithThrownException(); |
| state.restoreScratch(); |
| jit.copyCalleeSavesToVMCalleeSavesBuffer(); |
| if (state.needsToRestoreRegistersIfException()) { |
| // To the JIT that produces the original exception handling |
| // call site, they will expect the OSR exit to be arrived |
| // at from genericUnwind. Therefore we must model what genericUnwind |
| // does here. I.e, set callFrameForCatch and copy callee saves. |
| |
| jit.storePtr(GPRInfo::callFrameRegister, vm.addressOfCallFrameForCatch()); |
| CCallHelpers::Jump jumpToOSRExitExceptionHandler = jit.jump(); |
| |
| // We don't need to insert a new exception handler in the table |
| // because we're doing a manual exception check here. i.e, we'll |
| // never arrive here from genericUnwind(). |
| HandlerInfo originalHandler = state.originalExceptionHandler(); |
| state.callbacks.append( |
| [=] (LinkBuffer& linkBuffer) { |
| linkBuffer.link(jumpToOSRExitExceptionHandler, originalHandler.nativeCode); |
| }); |
| } else { |
| jit.setupArguments(CCallHelpers::TrustedImmPtr(&vm), GPRInfo::callFrameRegister); |
| lookupExceptionHandlerCall = jit.call(); |
| didSetLookupExceptionHandler = true; |
| jit.jumpToExceptionHandler(); |
| } |
| |
| noException.link(&jit); |
| state.restoreLiveRegistersFromStackForCall(isGetter()); |
| |
| state.callbacks.append( |
| [=] (LinkBuffer& linkBuffer) { |
| linkBuffer.link(operationCall, FunctionPtr(m_rareData->customAccessor.opaque)); |
| if (didSetLookupExceptionHandler) |
| linkBuffer.link(lookupExceptionHandlerCall, lookupExceptionHandler); |
| }); |
| } |
| state.succeed(); |
| return; |
| } |
| |
| case Replace: { |
| if (InferredType* type = structure()->inferredTypeFor(ident.impl())) { |
| if (verbose) |
| dataLog("Have type: ", type->descriptor(), "\n"); |
| state.failAndRepatch.append( |
| jit.branchIfNotType( |
| valueRegs, scratchGPR, type->descriptor(), CCallHelpers::DoNotHaveTagRegisters)); |
| } else if (verbose) |
| dataLog("Don't have type.\n"); |
| |
| if (isInlineOffset(m_offset)) { |
| jit.storeValue( |
| valueRegs, |
| CCallHelpers::Address( |
| baseGPR, |
| JSObject::offsetOfInlineStorage() + |
| offsetInInlineStorage(m_offset) * sizeof(JSValue))); |
| } else { |
| jit.loadPtr(CCallHelpers::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR); |
| jit.storeValue( |
| valueRegs, |
| CCallHelpers::Address( |
| scratchGPR, offsetInButterfly(m_offset) * sizeof(JSValue))); |
| } |
| state.succeed(); |
| return; |
| } |
| |
| case Transition: { |
| // AccessCase::transition() should have returned null. |
| RELEASE_ASSERT(GPRInfo::numberOfRegisters >= 6 || !structure()->outOfLineCapacity() || structure()->outOfLineCapacity() == newStructure()->outOfLineCapacity()); |
| RELEASE_ASSERT(!structure()->couldHaveIndexingHeader()); |
| |
| if (InferredType* type = newStructure()->inferredTypeFor(ident.impl())) { |
| if (verbose) |
| dataLog("Have type: ", type->descriptor(), "\n"); |
| state.failAndRepatch.append( |
| jit.branchIfNotType( |
| valueRegs, scratchGPR, type->descriptor(), CCallHelpers::DoNotHaveTagRegisters)); |
| } else if (verbose) |
| dataLog("Don't have type.\n"); |
| |
| CCallHelpers::JumpList slowPath; |
| |
| ScratchRegisterAllocator allocator(stubInfo.patch.usedRegisters); |
| allocator.lock(baseGPR); |
| #if USE(JSVALUE32_64) |
| allocator.lock(static_cast<GPRReg>(stubInfo.patch.baseTagGPR)); |
| #endif |
| allocator.lock(valueRegs); |
| allocator.lock(scratchGPR); |
| |
| GPRReg scratchGPR2 = allocator.allocateScratchGPR(); |
| GPRReg scratchGPR3; |
| if (newStructure()->outOfLineCapacity() != structure()->outOfLineCapacity() |
| && structure()->outOfLineCapacity()) |
| scratchGPR3 = allocator.allocateScratchGPR(); |
| else |
| scratchGPR3 = InvalidGPRReg; |
| |
| ScratchRegisterAllocator::PreservedState preservedState = |
| allocator.preserveReusedRegistersByPushing(jit, ScratchRegisterAllocator::ExtraStackSpace::SpaceForCCall); |
| |
| ASSERT(structure()->transitionWatchpointSetHasBeenInvalidated()); |
| |
| bool scratchGPRHasStorage = false; |
| bool needsToMakeRoomOnStackForCCall = !preservedState.numberOfBytesPreserved && codeBlock->jitType() == JITCode::FTLJIT; |
| |
| if (newStructure()->outOfLineCapacity() != structure()->outOfLineCapacity()) { |
| size_t newSize = newStructure()->outOfLineCapacity() * sizeof(JSValue); |
| CopiedAllocator* copiedAllocator = &vm.heap.storageAllocator(); |
| |
| if (!structure()->outOfLineCapacity()) { |
| jit.loadPtr(&copiedAllocator->m_currentRemaining, scratchGPR); |
| slowPath.append( |
| jit.branchSubPtr( |
| CCallHelpers::Signed, CCallHelpers::TrustedImm32(newSize), scratchGPR)); |
| jit.storePtr(scratchGPR, &copiedAllocator->m_currentRemaining); |
| jit.negPtr(scratchGPR); |
| jit.addPtr( |
| CCallHelpers::AbsoluteAddress(&copiedAllocator->m_currentPayloadEnd), scratchGPR); |
| jit.addPtr(CCallHelpers::TrustedImm32(sizeof(JSValue)), scratchGPR); |
| } else { |
| size_t oldSize = structure()->outOfLineCapacity() * sizeof(JSValue); |
| ASSERT(newSize > oldSize); |
| |
| jit.loadPtr(CCallHelpers::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR3); |
| jit.loadPtr(&copiedAllocator->m_currentRemaining, scratchGPR); |
| slowPath.append( |
| jit.branchSubPtr( |
| CCallHelpers::Signed, CCallHelpers::TrustedImm32(newSize), scratchGPR)); |
| jit.storePtr(scratchGPR, &copiedAllocator->m_currentRemaining); |
| jit.negPtr(scratchGPR); |
| jit.addPtr( |
| CCallHelpers::AbsoluteAddress(&copiedAllocator->m_currentPayloadEnd), scratchGPR); |
| jit.addPtr(CCallHelpers::TrustedImm32(sizeof(JSValue)), scratchGPR); |
| // We have scratchGPR = new storage, scratchGPR3 = old storage, |
| // scratchGPR2 = available |
| for (size_t offset = 0; offset < oldSize; offset += sizeof(void*)) { |
| jit.loadPtr( |
| CCallHelpers::Address( |
| scratchGPR3, |
| -static_cast<ptrdiff_t>( |
| offset + sizeof(JSValue) + sizeof(void*))), |
| scratchGPR2); |
| jit.storePtr( |
| scratchGPR2, |
| CCallHelpers::Address( |
| scratchGPR, |
| -static_cast<ptrdiff_t>(offset + sizeof(JSValue) + sizeof(void*)))); |
| } |
| } |
| |
| jit.storePtr(scratchGPR, CCallHelpers::Address(baseGPR, JSObject::butterflyOffset())); |
| scratchGPRHasStorage = true; |
| } |
| |
| uint32_t structureBits = bitwise_cast<uint32_t>(newStructure()->id()); |
| jit.store32( |
| CCallHelpers::TrustedImm32(structureBits), |
| CCallHelpers::Address(baseGPR, JSCell::structureIDOffset())); |
| |
| if (isInlineOffset(m_offset)) { |
| jit.storeValue( |
| valueRegs, |
| CCallHelpers::Address( |
| baseGPR, |
| JSObject::offsetOfInlineStorage() + |
| offsetInInlineStorage(m_offset) * sizeof(JSValue))); |
| } else { |
| if (!scratchGPRHasStorage) |
| jit.loadPtr(CCallHelpers::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR); |
| jit.storeValue( |
| valueRegs, |
| CCallHelpers::Address(scratchGPR, offsetInButterfly(m_offset) * sizeof(JSValue))); |
| } |
| |
| ScratchBuffer* scratchBuffer = nullptr; |
| if (newStructure()->outOfLineCapacity() != structure()->outOfLineCapacity()) |
| scratchBuffer = vm.scratchBufferForSize(allocator.desiredScratchBufferSizeForCall()); |
| |
| if (newStructure()->outOfLineCapacity() != structure()->outOfLineCapacity()) { |
| CCallHelpers::Call callFlushWriteBarrierBuffer; |
| CCallHelpers::Jump ownerIsRememberedOrInEden = jit.jumpIfIsRememberedOrInEden(baseGPR); |
| WriteBarrierBuffer& writeBarrierBuffer = jit.vm()->heap.writeBarrierBuffer(); |
| jit.load32(writeBarrierBuffer.currentIndexAddress(), scratchGPR2); |
| CCallHelpers::Jump needToFlush = |
| jit.branch32( |
| CCallHelpers::AboveOrEqual, scratchGPR2, |
| CCallHelpers::TrustedImm32(writeBarrierBuffer.capacity())); |
| |
| jit.add32(CCallHelpers::TrustedImm32(1), scratchGPR2); |
| jit.store32(scratchGPR2, writeBarrierBuffer.currentIndexAddress()); |
| |
| jit.move(CCallHelpers::TrustedImmPtr(writeBarrierBuffer.buffer()), scratchGPR); |
| // We use an offset of -sizeof(void*) because we already added 1 to scratchGPR2. |
| jit.storePtr( |
| baseGPR, |
| CCallHelpers::BaseIndex( |
| scratchGPR, scratchGPR2, CCallHelpers::ScalePtr, |
| static_cast<int32_t>(-sizeof(void*)))); |
| |
| CCallHelpers::Jump doneWithBarrier = jit.jump(); |
| needToFlush.link(&jit); |
| |
| // FIXME: We should restoreReusedRegistersByPopping() before this. Then, we wouldn't need |
| // padding in preserveReusedRegistersByPushing(). Or, maybe it would be even better if the |
| // barrier slow path was just the normal slow path, below. |
| // https://bugs.webkit.org/show_bug.cgi?id=149030 |
| allocator.preserveUsedRegistersToScratchBufferForCall(jit, scratchBuffer, scratchGPR2); |
| if (needsToMakeRoomOnStackForCCall) |
| jit.makeSpaceOnStackForCCall(); |
| jit.setupArgumentsWithExecState(baseGPR); |
| callFlushWriteBarrierBuffer = jit.call(); |
| if (needsToMakeRoomOnStackForCCall) |
| jit.reclaimSpaceOnStackForCCall(); |
| allocator.restoreUsedRegistersFromScratchBufferForCall( |
| jit, scratchBuffer, scratchGPR2); |
| |
| doneWithBarrier.link(&jit); |
| ownerIsRememberedOrInEden.link(&jit); |
| |
| state.callbacks.append( |
| [=] (LinkBuffer& linkBuffer) { |
| linkBuffer.link(callFlushWriteBarrierBuffer, operationFlushWriteBarrierBuffer); |
| }); |
| } |
| |
| allocator.restoreReusedRegistersByPopping(jit, preservedState); |
| state.succeed(); |
| |
| if (newStructure()->outOfLineCapacity() != structure()->outOfLineCapacity()) { |
| slowPath.link(&jit); |
| allocator.restoreReusedRegistersByPopping(jit, preservedState); |
| allocator.preserveUsedRegistersToScratchBufferForCall(jit, scratchBuffer, scratchGPR); |
| if (needsToMakeRoomOnStackForCCall) |
| jit.makeSpaceOnStackForCCall(); |
| #if USE(JSVALUE64) |
| jit.setupArgumentsWithExecState( |
| baseGPR, |
| CCallHelpers::TrustedImmPtr(newStructure()), |
| CCallHelpers::TrustedImm32(m_offset), |
| valueRegs.gpr()); |
| #else |
| jit.setupArgumentsWithExecState( |
| baseGPR, |
| CCallHelpers::TrustedImmPtr(newStructure()), |
| CCallHelpers::TrustedImm32(m_offset), |
| valueRegs.payloadGPR(), valueRegs.tagGPR()); |
| #endif |
| CCallHelpers::Call operationCall = jit.call(); |
| if (needsToMakeRoomOnStackForCCall) |
| jit.reclaimSpaceOnStackForCCall(); |
| allocator.restoreUsedRegistersFromScratchBufferForCall(jit, scratchBuffer, scratchGPR); |
| state.succeed(); |
| |
| state.callbacks.append( |
| [=] (LinkBuffer& linkBuffer) { |
| linkBuffer.link(operationCall, operationReallocateStorageAndFinishPut); |
| }); |
| } |
| return; |
| } |
| |
| case ArrayLength: { |
| jit.loadPtr(CCallHelpers::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR); |
| jit.load32(CCallHelpers::Address(scratchGPR, ArrayStorage::lengthOffset()), scratchGPR); |
| state.failAndIgnore.append( |
| jit.branch32(CCallHelpers::LessThan, scratchGPR, CCallHelpers::TrustedImm32(0))); |
| jit.boxInt32(scratchGPR, valueRegs, CCallHelpers::DoNotHaveTagRegisters); |
| state.succeed(); |
| return; |
| } |
| |
| case StringLength: { |
| jit.load32(CCallHelpers::Address(baseGPR, JSString::offsetOfLength()), valueRegs.payloadGPR()); |
| jit.boxInt32(valueRegs.payloadGPR(), valueRegs, CCallHelpers::DoNotHaveTagRegisters); |
| state.succeed(); |
| return; |
| } |
| |
| case IntrinsicGetter: { |
| RELEASE_ASSERT(isValidOffset(offset())); |
| |
| // We need to ensure the getter value does not move from under us. Note that GetterSetters |
| // are immutable so we just need to watch the property not any value inside it. |
| Structure* currStructure; |
| if (m_conditionSet.isEmpty()) |
| currStructure = structure(); |
| else |
| currStructure = m_conditionSet.slotBaseCondition().object()->structure(); |
| currStructure->startWatchingPropertyForReplacements(vm, offset()); |
| |
| emitIntrinsicGetter(state); |
| return; |
| } |
| |
| case MegamorphicLoad: |
| // These need to be handled by generateWithGuard(), since the guard is part of the megamorphic load |
| // algorithm. We can be sure that nobody will call generate() directly for MegamorphicLoad since |
| // MegamorphicLoad is not guarded by a structure check. |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| PolymorphicAccess::PolymorphicAccess() { } |
| PolymorphicAccess::~PolymorphicAccess() { } |
| |
| AccessGenerationResult PolymorphicAccess::regenerateWithCases( |
| VM& vm, CodeBlock* codeBlock, StructureStubInfo& stubInfo, const Identifier& ident, |
| Vector<std::unique_ptr<AccessCase>> originalCasesToAdd) |
| { |
| // This method will add the originalCasesToAdd to the list one at a time while preserving the |
| // invariants: |
| // - If a newly added case canReplace() any existing case, then the existing case is removed before |
| // the new case is added. Removal doesn't change order of the list. Any number of existing cases |
| // can be removed via the canReplace() rule. |
| // - Cases in the list always appear in ascending order of time of addition. Therefore, if you |
| // cascade through the cases in reverse order, you will get the most recent cases first. |
| // - If this method fails (returns null, doesn't add the cases), then both the previous case list |
| // and the previous stub are kept intact and the new cases are destroyed. It's OK to attempt to |
| // add more things after failure. |
| |
| // First ensure that the originalCasesToAdd doesn't contain duplicates. |
| Vector<std::unique_ptr<AccessCase>> casesToAdd; |
| for (unsigned i = 0; i < originalCasesToAdd.size(); ++i) { |
| std::unique_ptr<AccessCase> myCase = WTFMove(originalCasesToAdd[i]); |
| |
| // Add it only if it is not replaced by the subsequent cases in the list. |
| bool found = false; |
| for (unsigned j = i + 1; j < originalCasesToAdd.size(); ++j) { |
| if (originalCasesToAdd[j]->canReplace(*myCase)) { |
| found = true; |
| break; |
| } |
| } |
| |
| if (found) |
| continue; |
| |
| casesToAdd.append(WTFMove(myCase)); |
| } |
| |
| if (verbose) |
| dataLog("casesToAdd: ", listDump(casesToAdd), "\n"); |
| |
| // If there aren't any cases to add, then fail on the grounds that there's no point to generating a |
| // new stub that will be identical to the old one. Returning null should tell the caller to just |
| // keep doing what they were doing before. |
| if (casesToAdd.isEmpty()) |
| return AccessGenerationResult::MadeNoChanges; |
| |
| // Now construct the list of cases as they should appear if we are successful. This means putting |
| // all of the previous cases in this list in order but excluding those that can be replaced, and |
| // then adding the new cases. |
| ListType newCases; |
| for (auto& oldCase : m_list) { |
| // Ignore old cases that cannot possibly succeed anymore. |
| if (!oldCase->couldStillSucceed()) |
| continue; |
| |
| // Figure out if this is replaced by any new cases. |
| bool found = false; |
| for (auto& caseToAdd : casesToAdd) { |
| if (caseToAdd->canReplace(*oldCase)) { |
| found = true; |
| break; |
| } |
| } |
| if (found) |
| continue; |
| |
| newCases.append(oldCase->clone()); |
| } |
| for (auto& caseToAdd : casesToAdd) |
| newCases.append(WTFMove(caseToAdd)); |
| |
| if (verbose) |
| dataLog("newCases: ", listDump(newCases), "\n"); |
| |
| // See if we are close to having too many cases and if some of those cases can be subsumed by a |
| // megamorphic load. |
| if (newCases.size() >= Options::maxAccessVariantListSize()) { |
| unsigned numSelfLoads = 0; |
| for (auto& newCase : newCases) { |
| if (newCase->canBeReplacedByMegamorphicLoad()) |
| numSelfLoads++; |
| } |
| |
| if (numSelfLoads >= Options::megamorphicLoadCost()) { |
| if (auto mega = AccessCase::megamorphicLoad(vm, codeBlock)) { |
| newCases.removeAllMatching( |
| [&] (std::unique_ptr<AccessCase>& newCase) -> bool { |
| return newCase->canBeReplacedByMegamorphicLoad(); |
| }); |
| |
| newCases.append(WTFMove(mega)); |
| } |
| } |
| } |
| |
| if (newCases.size() > Options::maxAccessVariantListSize()) { |
| if (verbose) |
| dataLog("Too many cases.\n"); |
| return AccessGenerationResult::GaveUp; |
| } |
| |
| MacroAssemblerCodePtr result = regenerate(vm, codeBlock, stubInfo, ident, newCases); |
| if (!result) |
| return AccessGenerationResult::GaveUp; |
| |
| m_list = WTFMove(newCases); |
| return result; |
| } |
| |
| AccessGenerationResult PolymorphicAccess::regenerateWithCase( |
| VM& vm, CodeBlock* codeBlock, StructureStubInfo& stubInfo, const Identifier& ident, |
| std::unique_ptr<AccessCase> newAccess) |
| { |
| Vector<std::unique_ptr<AccessCase>> newAccesses; |
| newAccesses.append(WTFMove(newAccess)); |
| return regenerateWithCases(vm, codeBlock, stubInfo, ident, WTFMove(newAccesses)); |
| } |
| |
| bool PolymorphicAccess::visitWeak(VM& vm) const |
| { |
| for (unsigned i = 0; i < size(); ++i) { |
| if (!at(i).visitWeak(vm)) |
| return false; |
| } |
| if (Vector<WriteBarrier<JSCell>>* weakReferences = m_weakReferences.get()) { |
| for (WriteBarrier<JSCell>& weakReference : *weakReferences) { |
| if (!Heap::isMarked(weakReference.get())) |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void PolymorphicAccess::dump(PrintStream& out) const |
| { |
| out.print(RawPointer(this), ":["); |
| CommaPrinter comma; |
| for (auto& entry : m_list) |
| out.print(comma, *entry); |
| out.print("]"); |
| } |
| |
| MacroAssemblerCodePtr PolymorphicAccess::regenerate( |
| VM& vm, CodeBlock* codeBlock, StructureStubInfo& stubInfo, const Identifier& ident, |
| PolymorphicAccess::ListType& cases) |
| { |
| if (verbose) |
| dataLog("Generating code for cases: ", listDump(cases), "\n"); |
| |
| AccessGenerationState state; |
| |
| state.access = this; |
| state.stubInfo = &stubInfo; |
| state.ident = &ident; |
| |
| state.baseGPR = static_cast<GPRReg>(stubInfo.patch.baseGPR); |
| state.valueRegs = JSValueRegs( |
| #if USE(JSVALUE32_64) |
| static_cast<GPRReg>(stubInfo.patch.valueTagGPR), |
| #endif |
| static_cast<GPRReg>(stubInfo.patch.valueGPR)); |
| |
| ScratchRegisterAllocator allocator(stubInfo.patch.usedRegisters); |
| state.allocator = &allocator; |
| allocator.lock(state.baseGPR); |
| allocator.lock(state.valueRegs); |
| #if USE(JSVALUE32_64) |
| allocator.lock(static_cast<GPRReg>(stubInfo.patch.baseTagGPR)); |
| #endif |
| |
| state.scratchGPR = allocator.allocateScratchGPR(); |
| |
| CCallHelpers jit(&vm, codeBlock); |
| state.jit = &jit; |
| |
| state.preservedReusedRegisterState = |
| allocator.preserveReusedRegistersByPushing(jit, ScratchRegisterAllocator::ExtraStackSpace::NoExtraSpace); |
| |
| bool allGuardedByStructureCheck = true; |
| bool hasJSGetterSetterCall = false; |
| for (auto& entry : cases) { |
| allGuardedByStructureCheck &= entry->guardedByStructureCheck(); |
| if (entry->type() == AccessCase::Getter || entry->type() == AccessCase::Setter) |
| hasJSGetterSetterCall = true; |
| } |
| |
| if (cases.isEmpty()) { |
| // This is super unlikely, but we make it legal anyway. |
| state.failAndRepatch.append(jit.jump()); |
| } else if (!allGuardedByStructureCheck || cases.size() == 1) { |
| // If there are any proxies in the list, we cannot just use a binary switch over the structure. |
| // We need to resort to a cascade. A cascade also happens to be optimal if we only have just |
| // one case. |
| CCallHelpers::JumpList fallThrough; |
| |
| // Cascade through the list, preferring newer entries. |
| for (unsigned i = cases.size(); i--;) { |
| fallThrough.link(&jit); |
| cases[i]->generateWithGuard(state, fallThrough); |
| } |
| state.failAndRepatch.append(fallThrough); |
| } else { |
| jit.load32( |
| CCallHelpers::Address(state.baseGPR, JSCell::structureIDOffset()), |
| state.scratchGPR); |
| |
| Vector<int64_t> caseValues(cases.size()); |
| for (unsigned i = 0; i < cases.size(); ++i) |
| caseValues[i] = bitwise_cast<int32_t>(cases[i]->structure()->id()); |
| |
| BinarySwitch binarySwitch(state.scratchGPR, caseValues, BinarySwitch::Int32); |
| while (binarySwitch.advance(jit)) |
| cases[binarySwitch.caseIndex()]->generate(state); |
| state.failAndRepatch.append(binarySwitch.fallThrough()); |
| } |
| |
| if (!state.failAndIgnore.empty()) { |
| state.failAndIgnore.link(&jit); |
| |
| // Make sure that the inline cache optimization code knows that we are taking slow path because |
| // of something that isn't patchable. The slow path will decrement "countdown" and will only |
| // patch things if the countdown reaches zero. We increment the slow path count here to ensure |
| // that the slow path does not try to patch. |
| jit.load8(&stubInfo.countdown, state.scratchGPR); |
| jit.add32(CCallHelpers::TrustedImm32(1), state.scratchGPR); |
| jit.store8(state.scratchGPR, &stubInfo.countdown); |
| } |
| |
| CCallHelpers::JumpList failure; |
| if (allocator.didReuseRegisters()) { |
| state.failAndRepatch.link(&jit); |
| state.restoreScratch(); |
| } else |
| failure = state.failAndRepatch; |
| failure.append(jit.jump()); |
| |
| CodeBlock* codeBlockThatOwnsExceptionHandlers = nullptr; |
| CallSiteIndex callSiteIndexForExceptionHandling; |
| if (state.needsToRestoreRegistersIfException() && hasJSGetterSetterCall) { |
| // Emit the exception handler. |
| // Note that this code is only reachable when doing genericUnwind from a pure JS getter/setter . |
| // Note also that this is not reachable from custom getter/setter. Custom getter/setters will have |
| // their own exception handling logic that doesn't go through genericUnwind. |
| MacroAssembler::Label makeshiftCatchHandler = jit.label(); |
| |
| int stackPointerOffset = codeBlock->stackPointerOffset() * sizeof(EncodedJSValue); |
| stackPointerOffset -= state.preservedReusedRegisterState.numberOfBytesPreserved; |
| stackPointerOffset -= state.numberOfStackBytesUsedForRegisterPreservation(); |
| |
| jit.loadPtr(vm.addressOfCallFrameForCatch(), GPRInfo::callFrameRegister); |
| jit.addPtr(CCallHelpers::TrustedImm32(stackPointerOffset), GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister); |
| |
| state.restoreLiveRegistersFromStackForCallWithThrownException(); |
| state.restoreScratch(); |
| CCallHelpers::Jump jumpToOSRExitExceptionHandler = jit.jump(); |
| |
| HandlerInfo oldHandler = state.originalExceptionHandler(); |
| CallSiteIndex newExceptionHandlingCallSite = state.callSiteIndexForExceptionHandling(); |
| state.callbacks.append( |
| [=] (LinkBuffer& linkBuffer) { |
| linkBuffer.link(jumpToOSRExitExceptionHandler, oldHandler.nativeCode); |
| |
| HandlerInfo handlerToRegister = oldHandler; |
| handlerToRegister.nativeCode = linkBuffer.locationOf(makeshiftCatchHandler); |
| handlerToRegister.start = newExceptionHandlingCallSite.bits(); |
| handlerToRegister.end = newExceptionHandlingCallSite.bits() + 1; |
| codeBlock->appendExceptionHandler(handlerToRegister); |
| }); |
| |
| // We set these to indicate to the stub to remove itself from the CodeBlock's |
| // exception handler table when it is deallocated. |
| codeBlockThatOwnsExceptionHandlers = codeBlock; |
| ASSERT(JITCode::isOptimizingJIT(codeBlockThatOwnsExceptionHandlers->jitType())); |
| callSiteIndexForExceptionHandling = state.callSiteIndexForExceptionHandling(); |
| } |
| |
| LinkBuffer linkBuffer(vm, jit, codeBlock, JITCompilationCanFail); |
| if (linkBuffer.didFailToAllocate()) { |
| if (verbose) |
| dataLog("Did fail to allocate.\n"); |
| return MacroAssemblerCodePtr(); |
| } |
| |
| CodeLocationLabel successLabel = |
| stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToDone); |
| |
| linkBuffer.link(state.success, successLabel); |
| |
| linkBuffer.link( |
| failure, |
| stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToSlowCase)); |
| |
| for (auto callback : state.callbacks) |
| callback(linkBuffer); |
| |
| if (verbose) |
| dataLog(*codeBlock, " ", stubInfo.codeOrigin, ": Generating polymorphic access stub for ", listDump(cases), "\n"); |
| |
| MacroAssemblerCodeRef code = FINALIZE_CODE_FOR( |
| codeBlock, linkBuffer, |
| ("%s", toCString("Access stub for ", *codeBlock, " ", stubInfo.codeOrigin, " with return point ", successLabel, ": ", listDump(cases)).data())); |
| |
| bool doesCalls = false; |
| for (auto& entry : cases) |
| doesCalls |= entry->doesCalls(); |
| |
| m_stubRoutine = createJITStubRoutine(code, vm, codeBlock, doesCalls, nullptr, codeBlockThatOwnsExceptionHandlers, callSiteIndexForExceptionHandling); |
| m_watchpoints = WTFMove(state.watchpoints); |
| if (!state.weakReferences.isEmpty()) |
| m_weakReferences = std::make_unique<Vector<WriteBarrier<JSCell>>>(WTFMove(state.weakReferences)); |
| if (verbose) |
| dataLog("Returning: ", code.code(), "\n"); |
| return code.code(); |
| } |
| |
| void PolymorphicAccess::aboutToDie() |
| { |
| m_stubRoutine->aboutToDie(); |
| } |
| |
| } // namespace JSC |
| |
| namespace WTF { |
| |
| using namespace JSC; |
| |
| void printInternal(PrintStream& out, AccessGenerationResult::Kind kind) |
| { |
| switch (kind) { |
| case AccessGenerationResult::MadeNoChanges: |
| out.print("MadeNoChanges"); |
| return; |
| case AccessGenerationResult::GaveUp: |
| out.print("GaveUp"); |
| return; |
| case AccessGenerationResult::GeneratedNewCode: |
| out.print("GeneratedNewCode"); |
| return; |
| } |
| |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| void printInternal(PrintStream& out, AccessCase::AccessType type) |
| { |
| switch (type) { |
| case AccessCase::Load: |
| out.print("Load"); |
| return; |
| case AccessCase::MegamorphicLoad: |
| out.print("MegamorphicLoad"); |
| return; |
| case AccessCase::Transition: |
| out.print("Transition"); |
| return; |
| case AccessCase::Replace: |
| out.print("Replace"); |
| return; |
| case AccessCase::Miss: |
| out.print("Miss"); |
| return; |
| case AccessCase::GetGetter: |
| out.print("GetGetter"); |
| return; |
| case AccessCase::Getter: |
| out.print("Getter"); |
| return; |
| case AccessCase::Setter: |
| out.print("Setter"); |
| return; |
| case AccessCase::CustomValueGetter: |
| out.print("CustomValueGetter"); |
| return; |
| case AccessCase::CustomAccessorGetter: |
| out.print("CustomAccessorGetter"); |
| return; |
| case AccessCase::CustomValueSetter: |
| out.print("CustomValueSetter"); |
| return; |
| case AccessCase::CustomAccessorSetter: |
| out.print("CustomAccessorSetter"); |
| return; |
| case AccessCase::IntrinsicGetter: |
| out.print("IntrinsicGetter"); |
| return; |
| case AccessCase::InHit: |
| out.print("InHit"); |
| return; |
| case AccessCase::InMiss: |
| out.print("InMiss"); |
| return; |
| case AccessCase::ArrayLength: |
| out.print("ArrayLength"); |
| return; |
| case AccessCase::StringLength: |
| out.print("StringLength"); |
| return; |
| } |
| |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| } // namespace WTF |
| |
| #endif // ENABLE(JIT) |
| |
| |
