diff options
Diffstat (limited to 'Source/JavaScriptCore/bytecode/StructureStubInfo.h')
| -rw-r--r-- | Source/JavaScriptCore/bytecode/StructureStubInfo.h | 287 |
1 files changed, 82 insertions, 205 deletions
diff --git a/Source/JavaScriptCore/bytecode/StructureStubInfo.h b/Source/JavaScriptCore/bytecode/StructureStubInfo.h index 5463f3e95..40d362d44 100644 --- a/Source/JavaScriptCore/bytecode/StructureStubInfo.h +++ b/Source/JavaScriptCore/bytecode/StructureStubInfo.h @@ -1,5 +1,5 @@ /* - * Copyright (C) 2008, 2012, 2013 Apple Inc. All rights reserved. + * Copyright (C) 2008, 2012-2015 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -26,205 +26,121 @@ #ifndef StructureStubInfo_h #define StructureStubInfo_h -#include <wtf/Platform.h> - #include "CodeOrigin.h" #include "Instruction.h" #include "JITStubRoutine.h" #include "MacroAssembler.h" +#include "ObjectPropertyConditionSet.h" #include "Opcode.h" -#include "PolymorphicAccessStructureList.h" +#include "Options.h" +#include "PolymorphicAccess.h" #include "RegisterSet.h" #include "Structure.h" #include "StructureStubClearingWatchpoint.h" -#include <wtf/OwnPtr.h> namespace JSC { #if ENABLE(JIT) -class PolymorphicPutByIdList; +class PolymorphicAccess; -enum AccessType { - access_get_by_id_self, - access_get_by_id_proto, - access_get_by_id_chain, - access_get_by_id_self_list, - access_get_by_id_proto_list, - access_put_by_id_transition_normal, - access_put_by_id_transition_direct, - access_put_by_id_replace, - access_put_by_id_list, - access_unset, - access_get_by_id_generic, - access_put_by_id_generic, - access_get_array_length, - access_get_string_length, - access_in_list +enum class AccessType : int8_t { + Get, + Put, + In }; -inline bool isGetByIdAccess(AccessType accessType) -{ - switch (accessType) { - case access_get_by_id_self: - case access_get_by_id_proto: - case access_get_by_id_chain: - case access_get_by_id_self_list: - case access_get_by_id_proto_list: - case access_get_by_id_generic: - case access_get_array_length: - case access_get_string_length: - return true; - default: - return false; - } -} - -inline bool isPutByIdAccess(AccessType accessType) -{ - switch (accessType) { - case access_put_by_id_transition_normal: - case access_put_by_id_transition_direct: - case access_put_by_id_replace: - case access_put_by_id_list: - case access_put_by_id_generic: - return true; - default: - return false; - } -} - -inline bool isInAccess(AccessType accessType) -{ - switch (accessType) { - case access_in_list: - return true; - default: - return false; - } -} +enum class CacheType : int8_t { + Unset, + GetByIdSelf, + PutByIdReplace, + Stub +}; -struct StructureStubInfo { - StructureStubInfo() - : accessType(access_unset) - , seen(false) - , resetByGC(false) - { - } +class StructureStubInfo { + WTF_MAKE_NONCOPYABLE(StructureStubInfo); + WTF_MAKE_FAST_ALLOCATED; +public: + StructureStubInfo(AccessType); + ~StructureStubInfo(); - void initGetByIdSelf(VM& vm, JSCell* owner, Structure* baseObjectStructure) - { - accessType = access_get_by_id_self; + void initGetByIdSelf(CodeBlock*, Structure* baseObjectStructure, PropertyOffset); + void initPutByIdReplace(CodeBlock*, Structure* baseObjectStructure, PropertyOffset); + void initStub(CodeBlock*, std::unique_ptr<PolymorphicAccess>); - u.getByIdSelf.baseObjectStructure.set(vm, owner, baseObjectStructure); - } + MacroAssemblerCodePtr addAccessCase( + CodeBlock*, const Identifier&, std::unique_ptr<AccessCase>); - void initGetByIdChain(VM& vm, JSCell* owner, Structure* baseObjectStructure, StructureChain* chain, unsigned count, bool isDirect) - { - accessType = access_get_by_id_chain; + void reset(CodeBlock*); - u.getByIdChain.baseObjectStructure.set(vm, owner, baseObjectStructure); - u.getByIdChain.chain.set(vm, owner, chain); - u.getByIdChain.count = count; - u.getByIdChain.isDirect = isDirect; - } + void deref(); + void aboutToDie(); - void initGetByIdSelfList(PolymorphicAccessStructureList* structureList, int listSize, bool didSelfPatching = false) + // Check if the stub has weak references that are dead. If it does, then it resets itself, + // either entirely or just enough to ensure that those dead pointers don't get used anymore. + void visitWeakReferences(CodeBlock*); + + ALWAYS_INLINE bool considerCaching() { - accessType = access_get_by_id_self_list; - - u.getByIdSelfList.structureList = structureList; - u.getByIdSelfList.listSize = listSize; - u.getByIdSelfList.didSelfPatching = didSelfPatching; + everConsidered = true; + if (!countdown) { + // Check if we have been doing repatching too frequently. If so, then we should cool off + // for a while. + willRepatch(); + if (repatchCount > Options::repatchCountForCoolDown()) { + // We've been repatching too much, so don't do it now. + repatchCount = 0; + // The amount of time we require for cool-down depends on the number of times we've + // had to cool down in the past. The relationship is exponential. The max value we + // allow here is 2^256 - 2, since the slow paths may increment the count to indicate + // that they'd like to temporarily skip patching just this once. + countdown = WTF::leftShiftWithSaturation( + static_cast<uint8_t>(Options::initialCoolDownCount()), + numberOfCoolDowns, + static_cast<uint8_t>(std::numeric_limits<uint8_t>::max() - 1)); + willCoolDown(); + return false; + } + return true; + } + countdown--; + return false; } - void initGetByIdProtoList(PolymorphicAccessStructureList* structureList, int listSize) + ALWAYS_INLINE void willRepatch() { - accessType = access_get_by_id_proto_list; - - u.getByIdProtoList.structureList = structureList; - u.getByIdProtoList.listSize = listSize; + WTF::incrementWithSaturation(repatchCount); } - // PutById* - - void initPutByIdTransition(VM& vm, JSCell* owner, Structure* previousStructure, Structure* structure, StructureChain* chain, bool isDirect) + ALWAYS_INLINE void willCoolDown() { - if (isDirect) - accessType = access_put_by_id_transition_direct; - else - accessType = access_put_by_id_transition_normal; - - u.putByIdTransition.previousStructure.set(vm, owner, previousStructure); - u.putByIdTransition.structure.set(vm, owner, structure); - u.putByIdTransition.chain.set(vm, owner, chain); + WTF::incrementWithSaturation(numberOfCoolDowns); } - void initPutByIdReplace(VM& vm, JSCell* owner, Structure* baseObjectStructure) - { - accessType = access_put_by_id_replace; - - u.putByIdReplace.baseObjectStructure.set(vm, owner, baseObjectStructure); - } - - void initPutByIdList(PolymorphicPutByIdList* list) - { - accessType = access_put_by_id_list; - u.putByIdList.list = list; - } - - void initInList(PolymorphicAccessStructureList* list, int listSize) - { - accessType = access_in_list; - u.inList.structureList = list; - u.inList.listSize = listSize; - } - - void reset() - { - deref(); - accessType = access_unset; - stubRoutine.clear(); - watchpoints.clear(); - } + CodeLocationCall callReturnLocation; - void deref(); + CodeOrigin codeOrigin; + CallSiteIndex callSiteIndex; - bool visitWeakReferences(); - - bool seenOnce() - { - return seen; - } + bool containsPC(void* pc) const; - void setSeen() - { - seen = true; - } - - StructureStubClearingWatchpoint* addWatchpoint(CodeBlock* codeBlock) - { - return WatchpointsOnStructureStubInfo::ensureReferenceAndAddWatchpoint( - watchpoints, codeBlock, this); - } - - int8_t accessType; - bool seen : 1; - bool resetByGC : 1; - - CodeOrigin codeOrigin; + union { + struct { + WriteBarrierBase<Structure> baseObjectStructure; + PropertyOffset offset; + } byIdSelf; + PolymorphicAccess* stub; + } u; struct { - int8_t registersFlushed; - int8_t callFrameRegister; int8_t baseGPR; #if USE(JSVALUE32_64) int8_t valueTagGPR; + int8_t baseTagGPR; #endif int8_t valueGPR; RegisterSet usedRegisters; int32_t deltaCallToDone; - int32_t deltaCallToStorageLoad; int32_t deltaCallToJump; int32_t deltaCallToSlowCase; int32_t deltaCheckImmToCall; @@ -236,53 +152,14 @@ struct StructureStubInfo { #endif } patch; - union { - struct { - // It would be unwise to put anything here, as it will surely be overwritten. - } unset; - struct { - WriteBarrierBase<Structure> baseObjectStructure; - } getByIdSelf; - struct { - WriteBarrierBase<Structure> baseObjectStructure; - WriteBarrierBase<Structure> prototypeStructure; - bool isDirect; - } getByIdProto; - struct { - WriteBarrierBase<Structure> baseObjectStructure; - WriteBarrierBase<StructureChain> chain; - unsigned count : 31; - bool isDirect : 1; - } getByIdChain; - struct { - PolymorphicAccessStructureList* structureList; - int listSize : 31; - bool didSelfPatching : 1; - } getByIdSelfList; - struct { - PolymorphicAccessStructureList* structureList; - int listSize; - } getByIdProtoList; - struct { - WriteBarrierBase<Structure> previousStructure; - WriteBarrierBase<Structure> structure; - WriteBarrierBase<StructureChain> chain; - } putByIdTransition; - struct { - WriteBarrierBase<Structure> baseObjectStructure; - } putByIdReplace; - struct { - PolymorphicPutByIdList* list; - } putByIdList; - struct { - PolymorphicAccessStructureList* structureList; - int listSize; - } inList; - } u; - - RefPtr<JITStubRoutine> stubRoutine; - CodeLocationCall callReturnLocation; - RefPtr<WatchpointsOnStructureStubInfo> watchpoints; + AccessType accessType; + CacheType cacheType; + uint8_t countdown; // We repatch only when this is zero. If not zero, we decrement. + uint8_t repatchCount; + uint8_t numberOfCoolDowns; + bool resetByGC : 1; + bool tookSlowPath : 1; + bool everConsidered : 1; }; inline CodeOrigin getStructureStubInfoCodeOrigin(StructureStubInfo& structureStubInfo) @@ -290,7 +167,7 @@ inline CodeOrigin getStructureStubInfoCodeOrigin(StructureStubInfo& structureStu return structureStubInfo.codeOrigin; } -typedef HashMap<CodeOrigin, StructureStubInfo*> StubInfoMap; +typedef HashMap<CodeOrigin, StructureStubInfo*, CodeOriginApproximateHash> StubInfoMap; #else |