Changeset 209653 in webkit for trunk/Source/JavaScriptCore/jit/GPRInfo.h

Timestamp:

Dec 9, 2016, 11:32:38 PM (9 years ago)

Author:

[email protected]

Message:

JSVALUE64: Pass arguments in platform argument registers when making JavaScript calls
​https://bugs.webkit.org/show_bug.cgi?id=160355

Reviewed by Filip Pizlo.

JSTests:

New microbenchmarks to measure call type performance.

• microbenchmarks/calling-computed-args.js: Added.
• microbenchmarks/calling-many-callees.js: Added.
• microbenchmarks/calling-one-callee-fixed.js: Added.
• microbenchmarks/calling-one-callee.js: Added.
• microbenchmarks/calling-poly-callees.js: Added.
• microbenchmarks/calling-poly-extra-arity-callees.js: Added.
• microbenchmarks/calling-tailcall.js: Added.
• microbenchmarks/calling-virtual-arity-fixup-callees.js: Added.
• microbenchmarks/calling-virtual-arity-fixup-stackargs.js: Added.
• microbenchmarks/calling-virtual-callees.js: Added.
• microbenchmarks/calling-virtual-extra-arity-callees.js: Added.

Source/JavaScriptCore:

This patch implements passing JavaScript function arguments in registers for 64 bit platforms.

The implemented convention follows the ABI conventions for the associated platform.
The first two arguments are the callee and argument count, the rest of the argument registers
contain "this" and following argument until all platform argument registers are exhausted.
Arguments beyond what fit in registers are placed on the stack in the same location as
before this patch.

For X86-64 non-Windows platforms, there are 6 argument registers specified in the related ABI.
ARM64 has had argument registers. This allows for 4 or 6 parameter values to be placed in
registers on these respective platforms. This patch doesn't implement passing arguments in
registers for 32 bit platform, since most platforms have at most 4 argument registers
specified and 32 bit platforms use two 32 bit registers/memory locations to store one JSValue.

The call frame on the stack in unchanged in format and the arguments that are passed in
registers use the corresponding call frame location as a spill location. Arguments can
also be passed on the stack. The LLInt, baseline JIT'ed code as well as the initial entry
from C++ code base arguments on the stack. DFG s and FTL generated code pass arguments
via registers. All callees can accept arguments either in registers or on the stack.
The callee is responsible for moving argument to its preferred location.

The multiple entry points to JavaSCript code is now handled via the JITEntryPoints class and
related code. That class now has entries for StackArgsArityCheckNotRequired,
StackArgsMustCheckArity and for platforms that support registers arguments,
RegisterArgsArityCheckNotRequired, RegisterArgsMustCheckArity as well as and additional
RegisterArgsPossibleExtraArgs entry point when extra registers argument are passed.
This last case is needed to spill those extra arguments to the corresponding call frame
slots.

• JavaScriptCore.xcodeproj/project.pbxproj:
• b3/B3ArgumentRegValue.h:
• b3/B3Validate.cpp:
• bytecode/CallLinkInfo.cpp:

(JSC::CallLinkInfo::CallLinkInfo):

• bytecode/CallLinkInfo.h:

(JSC::CallLinkInfo::setUpCall):
(JSC::CallLinkInfo::argumentsLocation):
(JSC::CallLinkInfo::argumentsInRegisters):

• bytecode/PolymorphicAccess.cpp:

(JSC::AccessCase::generateImpl):

• dfg/DFGAbstractInterpreterInlines.h:

(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGCPSRethreadingPhase.cpp:

(JSC::DFG::CPSRethreadingPhase::canonicalizeLocalsInBlock):
(JSC::DFG::CPSRethreadingPhase::specialCaseArguments):
(JSC::DFG::CPSRethreadingPhase::computeIsFlushed):

• dfg/DFGClobberize.h:

(JSC::DFG::clobberize):

• dfg/DFGCommon.h:
• dfg/DFGDCEPhase.cpp:

(JSC::DFG::DCEPhase::run):

• dfg/DFGDoesGC.cpp:

(JSC::DFG::doesGC):

• dfg/DFGDriver.cpp:

(JSC::DFG::compileImpl):

• dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):

• dfg/DFGGenerationInfo.h:

(JSC::DFG::GenerationInfo::initArgumentRegisterValue):

• dfg/DFGGraph.cpp:

(JSC::DFG::Graph::dump):
(JSC::DFG::Graph::methodOfGettingAValueProfileFor):

• dfg/DFGGraph.h:

(JSC::DFG::Graph::needsFlushedThis):
(JSC::DFG::Graph::addImmediateShouldSpeculateInt32):

• dfg/DFGInPlaceAbstractState.cpp:

(JSC::DFG::InPlaceAbstractState::initialize):

• dfg/DFGJITCompiler.cpp:

(JSC::DFG::JITCompiler::link):
(JSC::DFG::JITCompiler::compile):
(JSC::DFG::JITCompiler::compileFunction):
(JSC::DFG::JITCompiler::compileEntry): Deleted.

• dfg/DFGJITCompiler.h:

(JSC::DFG::JITCompiler::addJSDirectCall):
(JSC::DFG::JITCompiler::JSDirectCallRecord::JSDirectCallRecord):
(JSC::DFG::JITCompiler::JSDirectCallRecord::hasSlowCall):

• dfg/DFGJITFinalizer.cpp:

(JSC::DFG::JITFinalizer::JITFinalizer):
(JSC::DFG::JITFinalizer::finalize):
(JSC::DFG::JITFinalizer::finalizeFunction):

• dfg/DFGJITFinalizer.h:
• dfg/DFGLiveCatchVariablePreservationPhase.cpp:

(JSC::DFG::LiveCatchVariablePreservationPhase::handleBlock):

• dfg/DFGMaximalFlushInsertionPhase.cpp:

(JSC::DFG::MaximalFlushInsertionPhase::treatRegularBlock):
(JSC::DFG::MaximalFlushInsertionPhase::treatRootBlock):

• dfg/DFGMayExit.cpp:
• dfg/DFGMinifiedNode.cpp:

(JSC::DFG::MinifiedNode::fromNode):

• dfg/DFGMinifiedNode.h:

(JSC::DFG::belongsInMinifiedGraph):

• dfg/DFGNode.cpp:

(JSC::DFG::Node::hasVariableAccessData):

• dfg/DFGNode.h:

(JSC::DFG::Node::accessesStack):
(JSC::DFG::Node::setVariableAccessData):
(JSC::DFG::Node::hasArgumentRegisterIndex):
(JSC::DFG::Node::argumentRegisterIndex):

• dfg/DFGNodeType.h:
• dfg/DFGOSRAvailabilityAnalysisPhase.cpp:

(JSC::DFG::LocalOSRAvailabilityCalculator::executeNode):

• dfg/DFGOSREntrypointCreationPhase.cpp:

(JSC::DFG::OSREntrypointCreationPhase::run):

• dfg/DFGPlan.cpp:

(JSC::DFG::Plan::compileInThreadImpl):

• dfg/DFGPreciseLocalClobberize.h:

(JSC::DFG::PreciseLocalClobberizeAdaptor::readTop):

• dfg/DFGPredictionInjectionPhase.cpp:

(JSC::DFG::PredictionInjectionPhase::run):

• dfg/DFGPredictionPropagationPhase.cpp:
• dfg/DFGPutStackSinkingPhase.cpp:
• dfg/DFGRegisterBank.h:

(JSC::DFG::RegisterBank::iterator::unlock):
(JSC::DFG::RegisterBank::unlockAtIndex):

• dfg/DFGSSAConversionPhase.cpp:

(JSC::DFG::SSAConversionPhase::run):

• dfg/DFGSafeToExecute.h:

(JSC::DFG::safeToExecute):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::SpeculativeJIT):
(JSC::DFG::SpeculativeJIT::clearGenerationInfo):
(JSC::DFG::dumpRegisterInfo):
(JSC::DFG::SpeculativeJIT::dump):
(JSC::DFG::SpeculativeJIT::compileCurrentBlock):
(JSC::DFG::SpeculativeJIT::checkArgumentTypes):
(JSC::DFG::SpeculativeJIT::setupArgumentRegistersForEntry):
(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT.h:

(JSC::DFG::SpeculativeJIT::allocate):
(JSC::DFG::SpeculativeJIT::spill):
(JSC::DFG::SpeculativeJIT::generationInfoFromVirtualRegister):
(JSC::DFG::JSValueOperand::JSValueOperand):
(JSC::DFG::JSValueOperand::gprUseSpecific):

• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::emitCall):
(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::fillJSValue):
(JSC::DFG::SpeculativeJIT::emitCall):
(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGStrengthReductionPhase.cpp:

(JSC::DFG::StrengthReductionPhase::handleNode):

• dfg/DFGThunks.cpp:

(JSC::DFG::osrEntryThunkGenerator):

• dfg/DFGVariableEventStream.cpp:

(JSC::DFG::VariableEventStream::reconstruct):

• dfg/DFGVirtualRegisterAllocationPhase.cpp:

(JSC::DFG::VirtualRegisterAllocationPhase::allocateRegister):
(JSC::DFG::VirtualRegisterAllocationPhase::run):

• ftl/FTLCapabilities.cpp:

(JSC::FTL::canCompile):

• ftl/FTLJITCode.cpp:

(JSC::FTL::JITCode::~JITCode):
(JSC::FTL::JITCode::initializeEntrypointThunk):
(JSC::FTL::JITCode::setEntryFor):
(JSC::FTL::JITCode::addressForCall):
(JSC::FTL::JITCode::executableAddressAtOffset):
(JSC::FTL::JITCode::initializeAddressForCall): Deleted.
(JSC::FTL::JITCode::initializeArityCheckEntrypoint): Deleted.

• ftl/FTLJITCode.h:
• ftl/FTLJITFinalizer.cpp:

(JSC::FTL::JITFinalizer::finalizeFunction):

• ftl/FTLLink.cpp:

(JSC::FTL::link):

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::lower):
(JSC::FTL::DFG::LowerDFGToB3::compileNode):
(JSC::FTL::DFG::LowerDFGToB3::compileGetArgumentRegister):
(JSC::FTL::DFG::LowerDFGToB3::compileCallOrConstruct):
(JSC::FTL::DFG::LowerDFGToB3::compileDirectCallOrConstruct):
(JSC::FTL::DFG::LowerDFGToB3::compileTailCall):
(JSC::FTL::DFG::LowerDFGToB3::compileCallOrConstructVarargsSpread):
(JSC::FTL::DFG::LowerDFGToB3::compileCallOrConstructVarargs):
(JSC::FTL::DFG::LowerDFGToB3::compileCallEval):

• ftl/FTLOSREntry.cpp:

(JSC::FTL::prepareOSREntry):

• ftl/FTLOutput.cpp:

(JSC::FTL::Output::argumentRegister):
(JSC::FTL::Output::argumentRegisterInt32):

• ftl/FTLOutput.h:
• interpreter/ShadowChicken.cpp:

(JSC::ShadowChicken::update):

• jit/AssemblyHelpers.cpp:

(JSC::AssemblyHelpers::emitDumbVirtualCall):

• jit/AssemblyHelpers.h:

(JSC::AssemblyHelpers::spillArgumentRegistersToFrameBeforePrologue):
(JSC::AssemblyHelpers::spillArgumentRegistersToFrame):
(JSC::AssemblyHelpers::fillArgumentRegistersFromFrameBeforePrologue):
(JSC::AssemblyHelpers::emitPutArgumentToCallFrameBeforePrologue):
(JSC::AssemblyHelpers::emitPutArgumentToCallFrame):
(JSC::AssemblyHelpers::emitGetFromCallFrameHeaderBeforePrologue):
(JSC::AssemblyHelpers::emitGetFromCallFrameArgumentBeforePrologue):
(JSC::AssemblyHelpers::emitGetPayloadFromCallFrameHeaderBeforePrologue):
(JSC::AssemblyHelpers::incrementCounter):

• jit/CachedRecovery.cpp:

(JSC::CachedRecovery::addTargetJSValueRegs):

• jit/CachedRecovery.h:

(JSC::CachedRecovery::gprTargets):
(JSC::CachedRecovery::setWantedFPR):
(JSC::CachedRecovery::wantedJSValueRegs):
(JSC::CachedRecovery::setWantedJSValueRegs): Deleted.

• jit/CallFrameShuffleData.h:
• jit/CallFrameShuffler.cpp:

(JSC::CallFrameShuffler::CallFrameShuffler):
(JSC::CallFrameShuffler::dump):
(JSC::CallFrameShuffler::tryWrites):
(JSC::CallFrameShuffler::prepareAny):

• jit/CallFrameShuffler.h:

(JSC::CallFrameShuffler::snapshot):
(JSC::CallFrameShuffler::addNew):
(JSC::CallFrameShuffler::initDangerFrontier):
(JSC::CallFrameShuffler::updateDangerFrontier):
(JSC::CallFrameShuffler::findDangerFrontierFrom):

• jit/CallFrameShuffler64.cpp:

(JSC::CallFrameShuffler::emitDisplace):

• jit/GPRInfo.h:

(JSC::JSValueRegs::operator==):
(JSC::JSValueRegs::operator!=):
(JSC::GPRInfo::toArgumentIndex):
(JSC::argumentRegisterFor):
(JSC::argumentRegisterForCallee):
(JSC::argumentRegisterForArgumentCount):
(JSC::argumentRegisterIndexForJSFunctionArgument):
(JSC::jsFunctionArgumentForArgumentRegister):
(JSC::argumentRegisterForFunctionArgument):
(JSC::numberOfRegisterArgumentsFor):

• jit/JIT.cpp:

(JSC::JIT::compileWithoutLinking):
(JSC::JIT::link):
(JSC::JIT::compileCTINativeCall): Deleted.

• jit/JIT.h:

(JSC::JIT::compileNativeCallEntryPoints):

• jit/JITCall.cpp:

(JSC::JIT::compileSetupVarargsFrame):
(JSC::JIT::compileCallEval):
(JSC::JIT::compileCallEvalSlowCase):
(JSC::JIT::compileOpCall):
(JSC::JIT::compileOpCallSlowCase):

• jit/JITCall32_64.cpp:

(JSC::JIT::compileCallEvalSlowCase):
(JSC::JIT::compileOpCall):
(JSC::JIT::compileOpCallSlowCase):

• jit/JITCode.cpp:

(JSC::JITCode::execute):
(JSC::DirectJITCode::DirectJITCode):
(JSC::DirectJITCode::initializeEntryPoints):
(JSC::DirectJITCode::addressForCall):
(JSC::NativeJITCode::addressForCall):
(JSC::DirectJITCode::initializeCodeRef): Deleted.

• jit/JITCode.h:

(JSC::JITCode::executableAddress): Deleted.

• jit/JITEntryPoints.h: Added.

(JSC::JITEntryPoints::JITEntryPoints):
(JSC::JITEntryPoints::entryFor):
(JSC::JITEntryPoints::setEntryFor):
(JSC::JITEntryPoints::offsetOfEntryFor):
(JSC::JITEntryPoints::registerEntryTypeForArgumentCount):
(JSC::JITEntryPoints::registerEntryTypeForArgumentType):
(JSC::JITEntryPoints::clearEntries):
(JSC::JITEntryPoints::operator=):
(JSC::JITEntryPointsWithRef::JITEntryPointsWithRef):
(JSC::JITEntryPointsWithRef::codeRef):
(JSC::argumentsLocationFor):
(JSC::registerEntryPointTypeFor):
(JSC::entryPointTypeFor):
(JSC::thunkEntryPointTypeFor):
(JSC::JITJSCallThunkEntryPointsWithRef::JITJSCallThunkEntryPointsWithRef):
(JSC::JITJSCallThunkEntryPointsWithRef::entryFor):
(JSC::JITJSCallThunkEntryPointsWithRef::setEntryFor):
(JSC::JITJSCallThunkEntryPointsWithRef::offsetOfEntryFor):
(JSC::JITJSCallThunkEntryPointsWithRef::clearEntries):
(JSC::JITJSCallThunkEntryPointsWithRef::codeRef):
(JSC::JITJSCallThunkEntryPointsWithRef::operator=):

• jit/JITOpcodes.cpp:

(JSC::JIT::privateCompileJITEntryNativeCall):
(JSC::JIT::privateCompileCTINativeCall): Deleted.

• jit/JITOpcodes32_64.cpp:

(JSC::JIT::privateCompileJITEntryNativeCall):
(JSC::JIT::privateCompileCTINativeCall): Deleted.

• jit/JITOperations.cpp:
• jit/JITThunks.cpp:

(JSC::JITThunks::jitEntryNativeCall):
(JSC::JITThunks::jitEntryNativeConstruct):
(JSC::JITThunks::jitEntryStub):
(JSC::JITThunks::jitCallThunkEntryStub):
(JSC::JITThunks::hostFunctionStub):
(JSC::JITThunks::ctiNativeCall): Deleted.
(JSC::JITThunks::ctiNativeConstruct): Deleted.

• jit/JITThunks.h:
• jit/JSInterfaceJIT.h:

(JSC::JSInterfaceJIT::emitJumpIfNotInt32):
(JSC::JSInterfaceJIT::emitLoadInt32):

• jit/RegisterSet.cpp:

(JSC::RegisterSet::argumentRegisters):

• jit/RegisterSet.h:
• jit/Repatch.cpp:

(JSC::linkSlowFor):
(JSC::revertCall):
(JSC::unlinkFor):
(JSC::linkVirtualFor):
(JSC::linkPolymorphicCall):

• jit/SpecializedThunkJIT.h:

(JSC::SpecializedThunkJIT::SpecializedThunkJIT):
(JSC::SpecializedThunkJIT::checkJSStringArgument):
(JSC::SpecializedThunkJIT::linkFailureHere):
(JSC::SpecializedThunkJIT::finalize):

• jit/ThunkGenerator.h:
• jit/ThunkGenerators.cpp:

(JSC::createRegisterArgumentsSpillEntry):
(JSC::slowPathFor):
(JSC::linkCallThunkGenerator):
(JSC::linkDirectCallThunkGenerator):
(JSC::linkPolymorphicCallThunkGenerator):
(JSC::virtualThunkFor):
(JSC::nativeForGenerator):
(JSC::nativeCallGenerator):
(JSC::nativeTailCallGenerator):
(JSC::nativeTailCallWithoutSavedTagsGenerator):
(JSC::nativeConstructGenerator):
(JSC::stringCharLoadRegCall):
(JSC::charCodeAtThunkGenerator):
(JSC::charAtThunkGenerator):
(JSC::fromCharCodeThunkGenerator):
(JSC::clz32ThunkGenerator):
(JSC::sqrtThunkGenerator):
(JSC::floorThunkGenerator):
(JSC::ceilThunkGenerator):
(JSC::truncThunkGenerator):
(JSC::roundThunkGenerator):
(JSC::expThunkGenerator):
(JSC::logThunkGenerator):
(JSC::absThunkGenerator):
(JSC::imulThunkGenerator):
(JSC::randomThunkGenerator):
(JSC::boundThisNoArgsFunctionCallGenerator):

• jit/ThunkGenerators.h:
• jsc.cpp:

(jscmain):

• llint/LLIntEntrypoint.cpp:

(JSC::LLInt::setFunctionEntrypoint):
(JSC::LLInt::setEvalEntrypoint):
(JSC::LLInt::setProgramEntrypoint):
(JSC::LLInt::setModuleProgramEntrypoint):

• llint/LLIntSlowPaths.cpp:

(JSC::LLInt::entryOSR):
(JSC::LLInt::setUpCall):

• llint/LLIntThunks.cpp:

(JSC::LLInt::generateThunkWithJumpTo):
(JSC::LLInt::functionForRegisterCallEntryThunkGenerator):
(JSC::LLInt::functionForStackCallEntryThunkGenerator):
(JSC::LLInt::functionForRegisterConstructEntryThunkGenerator):
(JSC::LLInt::functionForStackConstructEntryThunkGenerator):
(JSC::LLInt::functionForRegisterCallArityCheckThunkGenerator):
(JSC::LLInt::functionForStackCallArityCheckThunkGenerator):
(JSC::LLInt::functionForRegisterConstructArityCheckThunkGenerator):
(JSC::LLInt::functionForStackConstructArityCheckThunkGenerator):
(JSC::LLInt::functionForCallEntryThunkGenerator): Deleted.
(JSC::LLInt::functionForConstructEntryThunkGenerator): Deleted.
(JSC::LLInt::functionForCallArityCheckThunkGenerator): Deleted.
(JSC::LLInt::functionForConstructArityCheckThunkGenerator): Deleted.

• llint/LLIntThunks.h:
• runtime/ArityCheckMode.h:
• runtime/ExecutableBase.cpp:

(JSC::ExecutableBase::clearCode):

• runtime/ExecutableBase.h:

(JSC::ExecutableBase::entrypointFor):
(JSC::ExecutableBase::offsetOfEntryFor):
(JSC::ExecutableBase::offsetOfJITCodeWithArityCheckFor): Deleted.

• runtime/JSBoundFunction.cpp:

(JSC::boundThisNoArgsFunctionCall):

• runtime/NativeExecutable.cpp:

(JSC::NativeExecutable::finishCreation):

• runtime/ScriptExecutable.cpp:

(JSC::ScriptExecutable::installCode):

• runtime/VM.cpp:

(JSC::VM::VM):
(JSC::thunkGeneratorForIntrinsic):
(JSC::VM::clearCounters):
(JSC::VM::dumpCounters):

• runtime/VM.h:

(JSC::VM::getJITEntryStub):
(JSC::VM::getJITCallThunkEntryStub):
(JSC::VM::addressOfCounter):
(JSC::VM::counterFor):

• wasm/WasmBinding.cpp:

(JSC::Wasm::importStubGenerator):

Source/WTF:

Added a new build option ENABLE_VM_COUNTERS to enable JIT'able counters.
The default is for the option to be off.

• wtf/Platform.h:

Added ENABLE_VM_COUNTERS

File:

• trunk/Source/JavaScriptCore/jit/GPRInfo.h (modified) (17 diffs)

trunk/Source/JavaScriptCore/jit/GPRInfo.h

@@ -70 +70 @@
     explicit operator bool() const { return m_gpr != InvalidGPRReg; }
 
-    bool operator==(JSValueRegs other) { return m_gpr == other.m_gpr; }
-    bool operator!=(JSValueRegs other) { return !(*this == other); }
+    bool operator==(JSValueRegs other) const { return m_gpr == other.m_gpr; }
+    bool operator!=(JSValueRegs other) const { return !(*this == other); }
     
     GPRReg gpr() const { return m_gpr; }
@@ -332 +332 @@
 #if CPU(X86)
 #define NUMBER_OF_ARGUMENT_REGISTERS 0u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS 0u
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 0u
 
@@ -354 +355 @@
     static const GPRReg argumentGPR3 = X86Registers::ebx; // regT3
     static const GPRReg nonArgGPR0 = X86Registers::esi; // regT4
+    static const GPRReg nonArgGPR1 = X86Registers::edi; // regT5
     static const GPRReg returnValueGPR = X86Registers::eax; // regT0
     static const GPRReg returnValueGPR2 = X86Registers::edx; // regT1
@@ -378 +380 @@
         unsigned result = indexForRegister[reg];
         return result;
+    }
+
+    static unsigned toArgumentIndex(GPRReg reg)
+    {
+        ASSERT(reg != InvalidGPRReg);
+        ASSERT(static_cast<int>(reg) < 8);
+        static const unsigned indexForArgumentRegister[8] = { 2, 0, 1, 3, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex };
+        return indexForArgumentRegister[reg];
     }
 
@@ -400 +410 @@
 #define NUMBER_OF_ARGUMENT_REGISTERS 6u
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 5u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS (NUMBER_OF_ARGUMENT_REGISTERS - 2u)
 #else
 #define NUMBER_OF_ARGUMENT_REGISTERS 4u
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 7u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS 0u
 #endif
 
@@ -465 +477 @@
 #endif
     static const GPRReg nonArgGPR0 = X86Registers::r10; // regT5 (regT4 on Windows)
+    static const GPRReg nonArgGPR1 = X86Registers::eax; // regT0
     static const GPRReg returnValueGPR = X86Registers::eax; // regT0
     static const GPRReg returnValueGPR2 = X86Registers::edx; // regT1 or regT2
@@ -509 +522 @@
     }
 
+    static unsigned toArgumentIndex(GPRReg reg)
+    {
+        ASSERT(reg != InvalidGPRReg);
+        ASSERT(static_cast<int>(reg) < 16);
+#if !OS(WINDOWS)
+        static const unsigned indexForArgumentRegister[16] = { InvalidIndex, 3, 2, InvalidIndex, InvalidIndex, InvalidIndex, 1, 0, 4, 5, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex };
+#else
+        static const unsigned indexForArgumentRegister[16] = { InvalidIndex, 0, 1, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex, 2, 3, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex, InvalidIndex };
+#endif
+        return indexForArgumentRegister[reg];
+    }
+    
     static const char* debugName(GPRReg reg)
     {
@@ -539 +564 @@
 #if CPU(ARM)
 #define NUMBER_OF_ARGUMENT_REGISTERS 4u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS 0u
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 0u
 
@@ -602 +628 @@
     }
 
+    static unsigned toArgumentIndex(GPRReg reg)
+    {
+        ASSERT(reg != InvalidGPRReg);
+        ASSERT(static_cast<int>(reg) < 16);
+        if (reg > argumentGPR3)
+            return InvalidIndex;
+        return (unsigned)reg;
+    }
+    
     static const char* debugName(GPRReg reg)
     {
@@ -622 +657 @@
 #if CPU(ARM64)
 #define NUMBER_OF_ARGUMENT_REGISTERS 8u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS (NUMBER_OF_ARGUMENT_REGISTERS - 2u)
 // Callee Saves includes x19..x28 and FP registers q8..q15
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 18u
@@ -699 +735 @@
     COMPILE_ASSERT(ARM64Registers::q14 == 14, q14_is_14);
     COMPILE_ASSERT(ARM64Registers::q15 == 15, q15_is_15);
+
     static GPRReg toRegister(unsigned index)
     {
@@ -714 +751 @@
         ASSERT(index < numberOfArgumentRegisters);
         return toRegister(index);
+    }
+
+    static unsigned toArgumentIndex(GPRReg reg)
+    {
+        ASSERT(reg != InvalidGPRReg);
+        if (reg > argumentGPR7)
+            return InvalidIndex;
+        return (unsigned)reg;
     }
 
@@ -747 +792 @@
 #if CPU(MIPS)
 #define NUMBER_OF_ARGUMENT_REGISTERS 4u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS 0u
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 0u
 
@@ -774 +820 @@
     static const GPRReg argumentGPR3 = MIPSRegisters::a3;
     static const GPRReg nonArgGPR0 = regT4;
+    static const GPRReg nonArgGPR1 = regT5;
     static const GPRReg returnValueGPR = regT0;
     static const GPRReg returnValueGPR2 = regT1;
@@ -826 +873 @@
 #if CPU(SH4)
 #define NUMBER_OF_ARGUMENT_REGISTERS 4u
+#define NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS 0u
 #define NUMBER_OF_CALLEE_SAVES_REGISTERS 0u
 
@@ -856 +904 @@
     static const GPRReg argumentGPR3 = SH4Registers::r7; // regT3
     static const GPRReg nonArgGPR0 = regT4;
+    static const GPRReg nonArgGPR1 = regT5;
     static const GPRReg returnValueGPR = regT0;
     static const GPRReg returnValueGPR2 = regT1;
@@ -892 +941 @@
 #endif // CPU(SH4)
 
+inline GPRReg argumentRegisterFor(unsigned argumentIndex)
+{
+#if NUMBER_OF_ARGUMENT_REGISTERS
+    if (argumentIndex >= NUMBER_OF_ARGUMENT_REGISTERS)
+        return InvalidGPRReg;
+    return GPRInfo::toArgumentRegister(argumentIndex);
+#else
+    UNUSED_PARAM(argumentIndex);
+    RELEASE_ASSERT_NOT_REACHED();
+    return InvalidGPRReg;
+#endif
+}
+
+inline GPRReg argumentRegisterForCallee()
+{
+#if NUMBER_OF_ARGUMENT_REGISTERS
+    return argumentRegisterFor(0);
+#else
+    return GPRInfo::regT0;
+#endif
+}
+
+inline GPRReg argumentRegisterForArgumentCount()
+{
+    return argumentRegisterFor(1);
+}
+
+inline unsigned argumentRegisterIndexForJSFunctionArgument(unsigned argument)
+{
+    return argument + 2;
+}
+
+inline unsigned jsFunctionArgumentForArgumentRegisterIndex(unsigned index)
+{
+#if NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS > 0
+    ASSERT(index >= 2);
+    return index - 2;
+#else
+    UNUSED_PARAM(index);
+    RELEASE_ASSERT_NOT_REACHED();
+    return 0;
+#endif
+}
+
+inline unsigned jsFunctionArgumentForArgumentRegister(GPRReg gpr)
+{
+#if NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS > 0
+    unsigned argumentRegisterIndex = GPRInfo::toArgumentIndex(gpr);
+    ASSERT(argumentRegisterIndex != GPRInfo::InvalidIndex);
+    return jsFunctionArgumentForArgumentRegisterIndex(argumentRegisterIndex);
+#else
+    UNUSED_PARAM(gpr);
+    RELEASE_ASSERT_NOT_REACHED();
+    return 0;
+#endif
+}
+
+inline GPRReg argumentRegisterForFunctionArgument(unsigned argumentIndex)
+{
+    return argumentRegisterFor(argumentRegisterIndexForJSFunctionArgument(argumentIndex));
+}
+
+inline unsigned numberOfRegisterArgumentsFor(unsigned argumentCount)
+{
+    return std::min(argumentCount, NUMBER_OF_JS_FUNCTION_ARGUMENT_REGISTERS);
+}
+
 // The baseline JIT uses "accumulator" style execution with regT0 (for 64-bit)
 // and regT0 + regT1 (for 32-bit) serving as the accumulator register(s) for