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-rw-r--r--Source/JavaScriptCore/bytecode/StructureStubInfo.h347
1 files changed, 102 insertions, 245 deletions
diff --git a/Source/JavaScriptCore/bytecode/StructureStubInfo.h b/Source/JavaScriptCore/bytecode/StructureStubInfo.h
index f5c39357c..40d362d44 100644
--- a/Source/JavaScriptCore/bytecode/StructureStubInfo.h
+++ b/Source/JavaScriptCore/bytecode/StructureStubInfo.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2008, 2012 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
@@ -26,298 +26,155 @@
#ifndef StructureStubInfo_h
#define StructureStubInfo_h
-#include <wtf/Platform.h>
-
-#if ENABLE(JIT)
-
#include "CodeOrigin.h"
-#include "DFGRegisterSet.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 {
-class PolymorphicPutByIdList;
-
-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,
-};
-
-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;
- }
-}
-
-struct StructureStubInfo {
- StructureStubInfo()
- : accessType(access_unset)
- , seen(false)
- , resetByGC(false)
- {
- }
-
- void initGetByIdSelf(VM& vm, JSCell* owner, Structure* baseObjectStructure)
- {
- accessType = access_get_by_id_self;
-
- u.getByIdSelf.baseObjectStructure.set(vm, owner, baseObjectStructure);
- }
-
- void initGetByIdProto(VM& vm, JSCell* owner, Structure* baseObjectStructure, Structure* prototypeStructure, bool isDirect)
- {
- accessType = access_get_by_id_proto;
-
- u.getByIdProto.baseObjectStructure.set(vm, owner, baseObjectStructure);
- u.getByIdProto.prototypeStructure.set(vm, owner, prototypeStructure);
- u.getByIdProto.isDirect = isDirect;
- }
-
- void initGetByIdChain(VM& vm, JSCell* owner, Structure* baseObjectStructure, StructureChain* chain, unsigned count, bool isDirect)
- {
- accessType = access_get_by_id_chain;
-
- u.getByIdChain.baseObjectStructure.set(vm, owner, baseObjectStructure);
- u.getByIdChain.chain.set(vm, owner, chain);
- u.getByIdChain.count = count;
- u.getByIdChain.isDirect = isDirect;
- }
+#if ENABLE(JIT)
- void initGetByIdSelfList(PolymorphicAccessStructureList* structureList, int listSize)
- {
- accessType = access_get_by_id_self_list;
+class PolymorphicAccess;
- u.getByIdSelfList.structureList = structureList;
- u.getByIdSelfList.listSize = listSize;
- }
+enum class AccessType : int8_t {
+ Get,
+ Put,
+ In
+};
- void initGetByIdProtoList(PolymorphicAccessStructureList* structureList, int listSize)
- {
- accessType = access_get_by_id_proto_list;
+enum class CacheType : int8_t {
+ Unset,
+ GetByIdSelf,
+ PutByIdReplace,
+ Stub
+};
- u.getByIdProtoList.structureList = structureList;
- u.getByIdProtoList.listSize = listSize;
- }
+class StructureStubInfo {
+ WTF_MAKE_NONCOPYABLE(StructureStubInfo);
+ WTF_MAKE_FAST_ALLOCATED;
+public:
+ StructureStubInfo(AccessType);
+ ~StructureStubInfo();
- // PutById*
+ void initGetByIdSelf(CodeBlock*, Structure* baseObjectStructure, PropertyOffset);
+ void initPutByIdReplace(CodeBlock*, Structure* baseObjectStructure, PropertyOffset);
+ void initStub(CodeBlock*, std::unique_ptr<PolymorphicAccess>);
- void initPutByIdTransition(VM& vm, JSCell* owner, Structure* previousStructure, Structure* structure, StructureChain* chain, bool isDirect)
- {
- if (isDirect)
- accessType = access_put_by_id_transition_direct;
- else
- accessType = access_put_by_id_transition_normal;
+ MacroAssemblerCodePtr addAccessCase(
+ CodeBlock*, const Identifier&, std::unique_ptr<AccessCase>);
- u.putByIdTransition.previousStructure.set(vm, owner, previousStructure);
- u.putByIdTransition.structure.set(vm, owner, structure);
- u.putByIdTransition.chain.set(vm, owner, chain);
- }
-
- 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 reset()
- {
- deref();
- accessType = access_unset;
- stubRoutine.clear();
- watchpoints.clear();
- }
+ void reset(CodeBlock*);
void deref();
+ void aboutToDie();
- bool visitWeakReferences();
+ // 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*);
- bool seenOnce()
+ ALWAYS_INLINE bool considerCaching()
{
- return seen;
+ 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 setSeen()
+ ALWAYS_INLINE void willRepatch()
{
- seen = true;
+ WTF::incrementWithSaturation(repatchCount);
}
-
- StructureStubClearingWatchpoint* addWatchpoint(CodeBlock* codeBlock)
+
+ ALWAYS_INLINE void willCoolDown()
{
- return WatchpointsOnStructureStubInfo::ensureReferenceAndAddWatchpoint(
- watchpoints, codeBlock, this);
+ WTF::incrementWithSaturation(numberOfCoolDowns);
}
-
- unsigned bytecodeIndex;
- int8_t accessType;
- bool seen : 1;
- bool resetByGC : 1;
+ CodeLocationCall callReturnLocation;
-#if ENABLE(DFG_JIT)
CodeOrigin codeOrigin;
-#endif // ENABLE(DFG_JIT)
+ CallSiteIndex callSiteIndex;
+
+ bool containsPC(void* pc) const;
union {
struct {
- int8_t registersFlushed;
- int8_t baseGPR;
+ WriteBarrierBase<Structure> baseObjectStructure;
+ PropertyOffset offset;
+ } byIdSelf;
+ PolymorphicAccess* stub;
+ } u;
+
+ struct {
+ int8_t baseGPR;
#if USE(JSVALUE32_64)
- int8_t valueTagGPR;
-#endif
- int8_t valueGPR;
- DFG::RegisterSetPOD usedRegisters;
- int32_t deltaCallToDone;
- int32_t deltaCallToStorageLoad;
- int32_t deltaCallToStructCheck;
- int32_t deltaCallToSlowCase;
- int32_t deltaCheckImmToCall;
-#if USE(JSVALUE64)
- int32_t deltaCallToLoadOrStore;
-#else
- int32_t deltaCallToTagLoadOrStore;
- int32_t deltaCallToPayloadLoadOrStore;
+ int8_t valueTagGPR;
+ int8_t baseTagGPR;
#endif
- } dfg;
- struct {
- union {
- struct {
- int16_t structureToCompare;
- int16_t structureCheck;
- int16_t propertyStorageLoad;
+ int8_t valueGPR;
+ RegisterSet usedRegisters;
+ int32_t deltaCallToDone;
+ int32_t deltaCallToJump;
+ int32_t deltaCallToSlowCase;
+ int32_t deltaCheckImmToCall;
#if USE(JSVALUE64)
- int16_t displacementLabel;
+ int32_t deltaCallToLoadOrStore;
#else
- int16_t displacementLabel1;
- int16_t displacementLabel2;
+ int32_t deltaCallToTagLoadOrStore;
+ int32_t deltaCallToPayloadLoadOrStore;
#endif
- int16_t putResult;
- int16_t coldPathBegin;
- } get;
- struct {
- int16_t structureToCompare;
- int16_t propertyStorageLoad;
-#if USE(JSVALUE64)
- int16_t displacementLabel;
-#else
- int16_t displacementLabel1;
- int16_t displacementLabel2;
-#endif
- } put;
- } u;
- int16_t methodCheckProtoObj;
- int16_t methodCheckProtoStructureToCompare;
- int16_t methodCheckPutFunction;
- } baseline;
} 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;
- } 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;
- } u;
-
- RefPtr<JITStubRoutine> stubRoutine;
- CodeLocationCall callReturnLocation;
- CodeLocationLabel hotPathBegin;
- 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 void* getStructureStubInfoReturnLocation(StructureStubInfo* structureStubInfo)
+inline CodeOrigin getStructureStubInfoCodeOrigin(StructureStubInfo& structureStubInfo)
{
- return structureStubInfo->callReturnLocation.executableAddress();
+ return structureStubInfo.codeOrigin;
}
-inline unsigned getStructureStubInfoBytecodeIndex(StructureStubInfo* structureStubInfo)
-{
- return structureStubInfo->bytecodeIndex;
-}
+typedef HashMap<CodeOrigin, StructureStubInfo*, CodeOriginApproximateHash> StubInfoMap;
-} // namespace JSC
+#else
+
+typedef HashMap<int, void*> StubInfoMap;
#endif // ENABLE(JIT)
+} // namespace JSC
+
#endif // StructureStubInfo_h
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