Ignore:
Timestamp:
May 22, 2009, 6:48:32 PM (16 years ago)
Author:
[email protected]
Message:

2009-05-21 Gavin Barraclough <​[email protected]>

Reviewed by Geoff Garen.

op_method_check

Optimize method calls, by caching specific function values within the Structure.
The new opcode is used almost like an x86 opcode prefix byte to optimize op_get_by_id,
where the property access is being used to read a function to be passed to op-call (i.e.
'foo.bar();'). This patch modifies the Structure class such that when a property is
put to an object for the first time we will check if the value is a function. If it is,
we will cache the function value on the Structure. A Structure in such a state guarantees
that not only does a property with the given identifier exist on the object, but also that
its value is unchanged. Upon any further attempt to put a property with the same identifier
(but a different value) to the object, it will transition back to a normal Structure (where
it will guarantee the presence but not the value of the property).

op_method_check makes use of the new information made available by the Structure, by
augmenting the functionality of op_get_by_id. Upon generating a FunctionCallDotNode a
check will be emitted prior to the property access reading the function value, and the JIT
will generate an extra (initially unlinked but patchable) set of checks prior to the regular
JIT code for get_by_id. The new code will do inline structure and prototype structure check
(unlike a regular get_by_id, which can only handle 'self' accesses inline), and then performs
an immediate load of the function value, rather than using memory accesses to load the value
from the obejct's property storage array. If the method check fails it will revert, or if
the access is polymorphic, the op_get_by_id will continue to operate - and optimize itself -
just as any other regular op_get_by_id would.

~2.5% on v8-tests, due to a ~9% progression on richards.

  • API/JSCallbackObjectFunctions.h: (JSC::::put): (JSC::::staticFunctionGetter):
  • API/JSObjectRef.cpp: (JSObjectMakeConstructor):
  • JavaScriptCore.exp:
  • assembler/AbstractMacroAssembler.h: (JSC::AbstractMacroAssembler::differenceBetween):
  • assembler/MacroAssemblerX86.h: (JSC::MacroAssemblerX86::moveWithPatch):
  • bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump):
  • bytecode/CodeBlock.h: (JSC::getMethodCallLinkInfoReturnLocation): (JSC::CodeBlock::getMethodCallLinkInfo): (JSC::CodeBlock::addMethodCallLinkInfos): (JSC::CodeBlock::methodCallLinkInfo):
  • bytecode/Opcode.h:
  • bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::emitMethodCheck):
  • bytecompiler/BytecodeGenerator.h:
  • interpreter/Interpreter.cpp: (JSC::Interpreter::privateExecute):
  • jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): (JSC::JIT::privateCompileSlowCases): (JSC::JIT::privateCompile):
  • jit/JIT.h: (JSC::MethodCallCompilationInfo::MethodCallCompilationInfo):
  • jit/JITOpcodes.cpp:
  • jit/JITPropertyAccess.cpp: (JSC::JIT::emit_op_method_check): (JSC::JIT::emitSlow_op_method_check): (JSC::JIT::emit_op_get_by_id): (JSC::JIT::emitSlow_op_get_by_id): (JSC::JIT::emit_op_put_by_id): (JSC::JIT::emitSlow_op_put_by_id): (JSC::JIT::compileGetByIdHotPath): (JSC::JIT::compileGetByIdSlowCase): (JSC::JIT::patchMethodCallProto):
  • jit/JITStubs.cpp: (JSC::JITStubs::cti_op_get_by_id_method_check): (JSC::JITStubs::cti_op_get_by_id_method_check_second):
  • jit/JITStubs.h:
  • jsc.cpp: (GlobalObject::GlobalObject):
  • parser/Nodes.cpp: (JSC::FunctionCallDotNode::emitBytecode):
  • runtime/Arguments.cpp: (JSC::Arguments::put):
  • runtime/ArrayConstructor.cpp: (JSC::ArrayConstructor::ArrayConstructor):
  • runtime/BooleanConstructor.cpp: (JSC::BooleanConstructor::BooleanConstructor):
  • runtime/DateConstructor.cpp: (JSC::DateConstructor::DateConstructor):
  • runtime/ErrorConstructor.cpp: (JSC::ErrorConstructor::ErrorConstructor): (JSC::constructError):
  • runtime/ErrorPrototype.cpp: (JSC::ErrorPrototype::ErrorPrototype):
  • runtime/FunctionConstructor.cpp: (JSC::FunctionConstructor::FunctionConstructor):
  • runtime/FunctionPrototype.cpp: (JSC::FunctionPrototype::FunctionPrototype):
  • runtime/InternalFunction.cpp: (JSC::InternalFunction::InternalFunction):
  • runtime/JSActivation.cpp: (JSC::JSActivation::put): (JSC::JSActivation::putWithAttributes):
  • runtime/JSByteArray.cpp: (JSC::JSByteArray::JSByteArray):
  • runtime/JSFunction.cpp: (JSC::JSFunction::JSFunction): (JSC::JSFunction::getOwnPropertySlot):
  • runtime/JSGlobalObject.cpp: (JSC::JSGlobalObject::putWithAttributes): (JSC::JSGlobalObject::reset): (JSC::JSGlobalObject::mark):
  • runtime/JSGlobalObject.h: (JSC::JSGlobalObject::JSGlobalObjectData::JSGlobalObjectData): (JSC::JSGlobalObject::methodCallDummy):
  • runtime/JSObject.cpp: (JSC::JSObject::put): (JSC::JSObject::putWithAttributes): (JSC::JSObject::deleteProperty): (JSC::JSObject::defineGetter): (JSC::JSObject::defineSetter): (JSC::JSObject::getPropertyAttributes): (JSC::JSObject::getPropertySpecificFunction): (JSC::JSObject::putDirectFunction): (JSC::JSObject::putDirectFunctionWithoutTransition):
  • runtime/JSObject.h: (JSC::getJSFunction): (JSC::JSObject::getDirectLocation): (JSC::JSObject::putDirect): (JSC::JSObject::putDirectWithoutTransition):
  • runtime/LiteralParser.cpp: (JSC::LiteralParser::parseObject):
  • runtime/Lookup.cpp: (JSC::setUpStaticFunctionSlot):
  • runtime/Lookup.h: (JSC::lookupPut):
  • runtime/MathObject.cpp: (JSC::MathObject::MathObject):
  • runtime/NativeErrorConstructor.cpp: (JSC::NativeErrorConstructor::NativeErrorConstructor): (JSC::NativeErrorConstructor::construct):
  • runtime/NativeErrorPrototype.cpp: (JSC::NativeErrorPrototype::NativeErrorPrototype):
  • runtime/NumberConstructor.cpp: (JSC::NumberConstructor::NumberConstructor):
  • runtime/ObjectConstructor.cpp: (JSC::ObjectConstructor::ObjectConstructor):
  • runtime/PropertyMapHashTable.h: (JSC::PropertyMapEntry::PropertyMapEntry):
  • runtime/PrototypeFunction.cpp: (JSC::PrototypeFunction::PrototypeFunction):
  • runtime/PutPropertySlot.h: (JSC::PutPropertySlot::): (JSC::PutPropertySlot::PutPropertySlot): (JSC::PutPropertySlot::setNewProperty): (JSC::PutPropertySlot::setDespecifyFunctionProperty): (JSC::PutPropertySlot::isCacheable): (JSC::PutPropertySlot::cachedOffset):
  • runtime/RegExpConstructor.cpp: (JSC::RegExpConstructor::RegExpConstructor):
  • runtime/StringConstructor.cpp: (JSC::StringConstructor::StringConstructor):
  • runtime/StringPrototype.cpp: (JSC::StringPrototype::StringPrototype):
  • runtime/Structure.cpp: (JSC::Structure::Structure): (JSC::Structure::~Structure): (JSC::Structure::materializePropertyMap): (JSC::Structure::addPropertyTransitionToExistingStructure): (JSC::Structure::addPropertyTransition): (JSC::Structure::changeFunctionTransition): (JSC::Structure::addPropertyWithoutTransition): (JSC::Structure::get): (JSC::Structure::despecifyFunction): (JSC::Structure::put): (JSC::Structure::remove):
  • runtime/Structure.h: (JSC::Structure::get): (JSC::Structure::specificFunction):
  • runtime/StructureTransitionTable.h: (JSC::StructureTransitionTableHashTraits::emptyValue):
  • wtf/Platform.h:
File:
1 edited

Legend:

Unmodified
Added
Removed

  • trunk/JavaScriptCore/runtime/Structure.h

    r43432 r44076  
    6262        static void dumpStatistics();
    6363
    64         static PassRefPtr<Structure> addPropertyTransition(Structure*, const Identifier& propertyName, unsigned attributes, size_t& offset);
    65         static PassRefPtr<Structure> addPropertyTransitionToExistingStructure(Structure*, const Identifier& propertyName, unsigned attributes, size_t& offset);
     64        static PassRefPtr<Structure> addPropertyTransition(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
     65        static PassRefPtr<Structure> addPropertyTransitionToExistingStructure(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
    6666        static PassRefPtr<Structure> removePropertyTransition(Structure*, const Identifier& propertyName, size_t& offset);
    6767        static PassRefPtr<Structure> changePrototypeTransition(Structure*, JSValue prototype);
     68        static PassRefPtr<Structure> changeFunctionTransition(Structure*, const Identifier&);       
    6869        static PassRefPtr<Structure> getterSetterTransition(Structure*);
    6970        static PassRefPtr<Structure> toDictionaryTransition(Structure*);
    … …  
    7980
    8081        // These should be used with caution. 
    81         size_t addPropertyWithoutTransition(const Identifier& propertyName, unsigned attributes);
     82        size_t addPropertyWithoutTransition(const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
    8283        size_t removePropertyWithoutTransition(const Identifier& propertyName);
    8384        void setPrototypeWithoutTransition(JSValue prototype) { m_prototype = prototype; }
    … …  
    99100
    100101        size_t get(const Identifier& propertyName);
    101         size_t get(const Identifier& propertyName, unsigned& attributes);
     102        size_t get(const UString::Rep* rep, unsigned& attributes, JSCell*& specificValue);
     103        size_t get(const Identifier& propertyName, unsigned& attributes, JSCell*& specificValue)
     104        {
     105            ASSERT(!propertyName.isNull());
     106            return get(propertyName._ustring.rep(), attributes, specificValue);
     107        }
     108
    102109        void getEnumerablePropertyNames(ExecState*, PropertyNameArray&, JSObject*);
    103110
    … …  
    107114        bool isEmpty() const { return m_propertyTable ? !m_propertyTable->keyCount : m_offset == noOffset; }
    108115
     116        JSCell* specificValue() { return m_specificValueInPrevious; }
     117
    109118    private:
    110119        Structure(JSValue prototype, const TypeInfo&);
    111120
    112         size_t put(const Identifier& propertyName, unsigned attributes);
     121        size_t put(const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
    113122        size_t remove(const Identifier& propertyName);
    114123        void getEnumerableNamesFromPropertyTable(PropertyNameArray&);
    … …  
    123132        void checkConsistency();
    124133
     134        bool despecifyFunction(const Identifier&);
     135
    125136        PropertyMapHashTable* copyPropertyTable();
    126137        void materializePropertyMap();
    … …  
    160171            StructureTransitionTable* table;
    161172        } m_transitions;
     173        JSCell* m_specificValueInPrevious;
    162174
    163175        RefPtr<PropertyNameArrayData> m_cachedPropertyNameArrayData;
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