bool JITCompiler::compile(JITCode& entry)
{
setStartOfCode();
compileEntry();
SpeculativeJIT speculative(*this);
compileBody(speculative);
setEndOfMainPath();
// Generate slow path code.
speculative.runSlowPathGenerators();
compileExceptionHandlers();
linkOSRExits();
// Create OSR entry trampolines if necessary.
speculative.createOSREntries();
setEndOfCode();
LinkBuffer linkBuffer(*m_globalData, this, m_codeBlock, JITCompilationCanFail);
if (linkBuffer.didFailToAllocate())
return false;
link(linkBuffer);
speculative.linkOSREntries(linkBuffer);
if (m_disassembler)
m_disassembler->dump(linkBuffer);
entry = JITCode(
linkBuffer.finalizeCodeWithoutDisassembly(),
JITCode::DFGJIT);
return true;
}
MacroAssemblerCodeRef registerRestorationThunkGenerator(VM* vm)
{
AssemblyHelpers jit(vm, 0);
generateRegisterRestoration(jit);
LinkBuffer linkBuffer(*vm, &jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(linkBuffer, ("Register restoration thunk"));
}
Compilation::Compilation(VM& vm, Procedure& proc, unsigned optLevel)
{
CCallHelpers jit(&vm);
generate(proc, jit, optLevel);
LinkBuffer linkBuffer(vm, jit, nullptr);
m_codeRef = FINALIZE_CODE(linkBuffer, ("B3::Compilation"));
m_byproducts = proc.takeByproducts();
}
Compilation compile(VM& vm, Procedure& proc, unsigned optLevel)
{
TimingScope timingScope("Compilation");
prepareForGeneration(proc, optLevel);
CCallHelpers jit(&vm);
generate(proc, jit);
LinkBuffer linkBuffer(vm, jit, nullptr);
return Compilation(FINALIZE_CODE(linkBuffer, ("B3::Compilation")), proc.releaseByproducts());
}
void JITCompiler::compile(JITCode& entry)
{
compileEntry();
SpeculativeJIT speculative(*this);
compileBody(speculative);
LinkBuffer linkBuffer(*m_globalData, this);
link(linkBuffer);
speculative.linkOSREntries(linkBuffer);
entry = JITCode(linkBuffer.finalizeCode(), JITCode::DFGJIT);
}
void generateICFastPath(
State& state, CodeBlock* codeBlock, GeneratedFunction generatedFunction,
StackMaps::RecordMap& recordMap, DescriptorType& ic, size_t sizeOfIC)
{
VM& vm = state.graph.m_vm;
StackMaps::RecordMap::iterator iter = recordMap.find(ic.stackmapID());
if (iter == recordMap.end()) {
// It was optimized out.
return;
}
Vector<StackMaps::Record>& records = iter->value;
RELEASE_ASSERT(records.size() == ic.m_generators.size());
for (unsigned i = records.size(); i--;) {
StackMaps::Record& record = records[i];
auto generator = ic.m_generators[i];
CCallHelpers fastPathJIT(&vm, codeBlock);
generator.generateFastPath(fastPathJIT);
char* startOfIC =
bitwise_cast<char*>(generatedFunction) + record.instructionOffset;
LinkBuffer linkBuffer(vm, fastPathJIT, startOfIC, sizeOfIC);
// Note: we could handle the !isValid() case. We just don't appear to have a
// reason to do so, yet.
RELEASE_ASSERT(linkBuffer.isValid());
MacroAssembler::AssemblerType_T::fillNops(
startOfIC + linkBuffer.size(), sizeOfIC - linkBuffer.size());
state.finalizer->sideCodeLinkBuffer->link(
ic.m_slowPathDone[i], CodeLocationLabel(startOfIC + sizeOfIC));
linkBuffer.link(
generator.slowPathJump(),
state.finalizer->sideCodeLinkBuffer->locationOf(generator.slowPathBegin()));
generator.finalize(linkBuffer, *state.finalizer->sideCodeLinkBuffer);
}
}
void LazySlowPath::generate(CodeBlock* codeBlock)
{
RELEASE_ASSERT(!m_stub);
VM& vm = *codeBlock->vm();
CCallHelpers jit(&vm, codeBlock);
GenerationParams params;
CCallHelpers::JumpList exceptionJumps;
params.exceptionJumps = m_exceptionTarget ? &exceptionJumps : nullptr;
params.lazySlowPath = this;
unsigned bytesSaved = m_scratchRegisterAllocator.preserveReusedRegistersByPushing(jit, ScratchRegisterAllocator::ExtraStackSpace::NoExtraSpace);
// This is needed because LLVM may create a stackmap location that is the register SP.
// But on arm64, SP is also the same register number as ZR, so LLVM is telling us that it has
// proven something is zero. Our MASM isn't universally compatible with arm64's context dependent
// notion of SP meaning ZR. We just make things easier by ensuring we do the necessary move of zero
// into a non-SP register.
if (m_newZeroValueRegister != InvalidGPRReg)
jit.move(CCallHelpers::TrustedImm32(0), m_newZeroValueRegister);
m_generator->run(jit, params);
CCallHelpers::Label doneLabel;
CCallHelpers::Jump jumpToEndOfPatchpoint;
if (bytesSaved) {
doneLabel = jit.label();
m_scratchRegisterAllocator.restoreReusedRegistersByPopping(jit, bytesSaved, ScratchRegisterAllocator::ExtraStackSpace::NoExtraSpace);
jumpToEndOfPatchpoint = jit.jump();
}
LinkBuffer linkBuffer(vm, jit, codeBlock, JITCompilationMustSucceed);
if (bytesSaved) {
linkBuffer.link(params.doneJumps, linkBuffer.locationOf(doneLabel));
linkBuffer.link(jumpToEndOfPatchpoint, m_patchpoint.labelAtOffset(MacroAssembler::maxJumpReplacementSize()));
} else
linkBuffer.link(params.doneJumps, m_patchpoint.labelAtOffset(MacroAssembler::maxJumpReplacementSize()));
if (m_exceptionTarget)
linkBuffer.link(exceptionJumps, m_exceptionTarget);
m_stub = FINALIZE_CODE_FOR(codeBlock, linkBuffer, ("Lazy slow path call stub"));
MacroAssembler::replaceWithJump(m_patchpoint, CodeLocationLabel(m_stub.code()));
}
bool JITCompiler::compile(JITCode& entry)
{
SamplingRegion samplingRegion("DFG Backend");
setStartOfCode();
compileEntry();
SpeculativeJIT speculative(*this);
compileBody(speculative);
setEndOfMainPath();
// Generate slow path code.
speculative.runSlowPathGenerators();
compileExceptionHandlers();
linkOSRExits();
// Create OSR entry trampolines if necessary.
speculative.createOSREntries();
setEndOfCode();
LinkBuffer linkBuffer(*m_vm, this, m_codeBlock, JITCompilationCanFail);
if (linkBuffer.didFailToAllocate())
return false;
link(linkBuffer);
speculative.linkOSREntries(linkBuffer);
if (shouldShowDisassembly())
m_disassembler->dump(linkBuffer);
if (m_graph.m_compilation)
m_disassembler->reportToProfiler(m_graph.m_compilation.get(), linkBuffer);
entry = JITCode(
linkBuffer.finalizeCodeWithoutDisassembly(),
JITCode::DFGJIT);
return true;
}
void JITCompiler::compileFunction(JITCode& entry, MacroAssemblerCodePtr& entryWithArityCheck)
{
// === Stage 1 - Function header code generation ===
//
// This code currently matches the old JIT. In the function header we need to
// pop the return address (since we do not allow any recursion on the machine
// stack), and perform a fast register file check.
// This is the main entry point, without performing an arity check.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=56292
// We'll need to convert the remaining cti_ style calls (specifically the register file
// check) which will be dependent on stack layout. (We'd need to account for this in
// both normal return code and when jumping to an exception handler).
preserveReturnAddressAfterCall(GPRInfo::regT2);
emitPutToCallFrameHeader(GPRInfo::regT2, RegisterFile::ReturnPC);
// If we needed to perform an arity check we will already have moved the return address,
// so enter after this.
Label fromArityCheck(this);
// Setup a pointer to the codeblock in the CallFrameHeader.
emitPutImmediateToCallFrameHeader(m_codeBlock, RegisterFile::CodeBlock);
// Plant a check that sufficient space is available in the RegisterFile.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=56291
addPtr(Imm32(m_codeBlock->m_numCalleeRegisters * sizeof(Register)), GPRInfo::callFrameRegister, GPRInfo::regT1);
Jump registerFileCheck = branchPtr(Below, AbsoluteAddress(m_globalData->interpreter->registerFile().addressOfEnd()), GPRInfo::regT1);
// Return here after register file check.
Label fromRegisterFileCheck = label();
// === Stage 2 - Function body code generation ===
//
// We generate the speculative code path, followed by the non-speculative
// code for the function. Next we need to link the two together, making
// bail-outs from the speculative path jump to the corresponding point on
// the non-speculative one (and generating any code necessary to juggle
// register values around, rebox values, and ensure spilled, to match the
// non-speculative path's requirements).
#if DFG_JIT_BREAK_ON_EVERY_FUNCTION
// Handy debug tool!
breakpoint();
#endif
// First generate the speculative path.
Label speculativePathBegin = label();
SpeculativeJIT speculative(*this);
#if !DFG_DEBUG_LOCAL_DISBALE_SPECULATIVE
bool compiledSpeculative = speculative.compile();
#else
bool compiledSpeculative = false;
#endif
// Next, generate the non-speculative path. We pass this a SpeculationCheckIndexIterator
// to allow it to check which nodes in the graph may bail out, and may need to reenter the
// non-speculative path.
if (compiledSpeculative) {
SpeculationCheckIndexIterator checkIterator(speculative.speculationChecks());
NonSpeculativeJIT nonSpeculative(*this);
nonSpeculative.compile(checkIterator);
// Link the bail-outs from the speculative path to the corresponding entry points into the non-speculative one.
linkSpeculationChecks(speculative, nonSpeculative);
} else {
// If compilation through the SpeculativeJIT failed, throw away the code we generated.
m_calls.clear();
rewindToLabel(speculativePathBegin);
SpeculationCheckVector noChecks;
SpeculationCheckIndexIterator checkIterator(noChecks);
NonSpeculativeJIT nonSpeculative(*this);
nonSpeculative.compile(checkIterator);
}
// === Stage 3 - Function footer code generation ===
//
// Generate code to lookup and jump to exception handlers, to perform the slow
// register file check (if the fast one in the function header fails), and
// generate the entry point with arity check.
// Iterate over the m_calls vector, checking for exception checks,
// and linking them to here.
unsigned exceptionCheckCount = 0;
for (unsigned i = 0; i < m_calls.size(); ++i) {
Jump& exceptionCheck = m_calls[i].m_exceptionCheck;
if (exceptionCheck.isSet()) {
exceptionCheck.link(this);
++exceptionCheckCount;
}
}
// If any exception checks were linked, generate code to lookup a handler.
if (exceptionCheckCount) {
// lookupExceptionHandler is passed two arguments, exec (the CallFrame*), and
// an identifier for the operation that threw the exception, which we can use
// to look up handler information. The identifier we use is the return address
// of the call out from JIT code that threw the exception; this is still
// available on the stack, just below the stack pointer!
move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
peek(GPRInfo::argumentGPR1, -1);
m_calls.append(CallRecord(call(), lookupExceptionHandler));
// lookupExceptionHandler leaves the handler CallFrame* in the returnValueGPR,
// and the address of the handler in returnValueGPR2.
jump(GPRInfo::returnValueGPR2);
}
// Generate the register file check; if the fast check in the function head fails,
// we need to call out to a helper function to check whether more space is available.
// FIXME: change this from a cti call to a DFG style operation (normal C calling conventions).
registerFileCheck.link(this);
move(stackPointerRegister, GPRInfo::argumentGPR0);
poke(GPRInfo::callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
Call callRegisterFileCheck = call();
jump(fromRegisterFileCheck);
// The fast entry point into a function does not check the correct number of arguments
// have been passed to the call (we only use the fast entry point where we can statically
// determine the correct number of arguments have been passed, or have already checked).
// In cases where an arity check is necessary, we enter here.
// FIXME: change this from a cti call to a DFG style operation (normal C calling conventions).
Label arityCheck = label();
preserveReturnAddressAfterCall(GPRInfo::regT2);
emitPutToCallFrameHeader(GPRInfo::regT2, RegisterFile::ReturnPC);
branch32(Equal, GPRInfo::regT1, Imm32(m_codeBlock->m_numParameters)).linkTo(fromArityCheck, this);
move(stackPointerRegister, GPRInfo::argumentGPR0);
poke(GPRInfo::callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
Call callArityCheck = call();
move(GPRInfo::regT0, GPRInfo::callFrameRegister);
jump(fromArityCheck);
// === Stage 4 - Link ===
//
// Link the code, populate data in CodeBlock data structures.
LinkBuffer linkBuffer(*m_globalData, this, m_globalData->executableAllocator);
#if DFG_DEBUG_VERBOSE
fprintf(stderr, "JIT code start at %p\n", linkBuffer.debugAddress());
#endif
// Link all calls out from the JIT code to their respective functions.
for (unsigned i = 0; i < m_calls.size(); ++i)
linkBuffer.link(m_calls[i].m_call, m_calls[i].m_function);
if (m_codeBlock->needsCallReturnIndices()) {
m_codeBlock->callReturnIndexVector().reserveCapacity(exceptionCheckCount);
for (unsigned i = 0; i < m_calls.size(); ++i) {
if (m_calls[i].m_exceptionCheck.isSet()) {
unsigned returnAddressOffset = linkBuffer.returnAddressOffset(m_calls[i].m_call);
unsigned exceptionInfo = m_calls[i].m_exceptionInfo;
m_codeBlock->callReturnIndexVector().append(CallReturnOffsetToBytecodeOffset(returnAddressOffset, exceptionInfo));
}
}
}
// FIXME: switch the register file check & arity check over to DFGOpertaion style calls, not JIT stubs.
linkBuffer.link(callRegisterFileCheck, cti_register_file_check);
linkBuffer.link(callArityCheck, m_codeBlock->m_isConstructor ? cti_op_construct_arityCheck : cti_op_call_arityCheck);
entryWithArityCheck = linkBuffer.locationOf(arityCheck);
entry = linkBuffer.finalizeCode();
}
static void fixFunctionBasedOnStackMaps(
State& state, CodeBlock* codeBlock, JITCode* jitCode, GeneratedFunction generatedFunction,
StackMaps::RecordMap& recordMap, bool didSeeUnwindInfo)
{
Graph& graph = state.graph;
VM& vm = graph.m_vm;
StackMaps stackmaps = jitCode->stackmaps;
int localsOffset =
offsetOfStackRegion(recordMap, state.capturedStackmapID) + graph.m_nextMachineLocal;
int varargsSpillSlotsOffset;
if (state.varargsSpillSlotsStackmapID != UINT_MAX)
varargsSpillSlotsOffset = offsetOfStackRegion(recordMap, state.varargsSpillSlotsStackmapID);
else
varargsSpillSlotsOffset = 0;
for (unsigned i = graph.m_inlineVariableData.size(); i--;) {
InlineCallFrame* inlineCallFrame = graph.m_inlineVariableData[i].inlineCallFrame;
if (inlineCallFrame->argumentsRegister.isValid())
inlineCallFrame->argumentsRegister += localsOffset;
if (inlineCallFrame->argumentCountRegister.isValid())
inlineCallFrame->argumentCountRegister += localsOffset;
for (unsigned argument = inlineCallFrame->arguments.size(); argument-- > 1;) {
inlineCallFrame->arguments[argument] =
inlineCallFrame->arguments[argument].withLocalsOffset(localsOffset);
}
if (inlineCallFrame->isClosureCall) {
inlineCallFrame->calleeRecovery =
inlineCallFrame->calleeRecovery.withLocalsOffset(localsOffset);
}
}
if (codeBlock->usesArguments()) {
codeBlock->setArgumentsRegister(
VirtualRegister(codeBlock->argumentsRegister().offset() + localsOffset));
}
MacroAssembler::Label stackOverflowException;
{
CCallHelpers checkJIT(&vm, codeBlock);
// At this point it's perfectly fair to just blow away all state and restore the
// JS JIT view of the universe.
checkJIT.move(MacroAssembler::TrustedImmPtr(&vm), GPRInfo::argumentGPR0);
checkJIT.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
MacroAssembler::Call callLookupExceptionHandler = checkJIT.call();
checkJIT.jumpToExceptionHandler();
stackOverflowException = checkJIT.label();
checkJIT.move(MacroAssembler::TrustedImmPtr(&vm), GPRInfo::argumentGPR0);
checkJIT.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
MacroAssembler::Call callLookupExceptionHandlerFromCallerFrame = checkJIT.call();
checkJIT.jumpToExceptionHandler();
auto linkBuffer = std::make_unique<LinkBuffer>(
vm, checkJIT, codeBlock, JITCompilationMustSucceed);
linkBuffer->link(callLookupExceptionHandler, FunctionPtr(lookupExceptionHandler));
linkBuffer->link(callLookupExceptionHandlerFromCallerFrame, FunctionPtr(lookupExceptionHandlerFromCallerFrame));
state.finalizer->handleExceptionsLinkBuffer = WTF::move(linkBuffer);
}
ExitThunkGenerator exitThunkGenerator(state);
exitThunkGenerator.emitThunks();
if (exitThunkGenerator.didThings()) {
RELEASE_ASSERT(state.finalizer->osrExit.size());
RELEASE_ASSERT(didSeeUnwindInfo);
auto linkBuffer = std::make_unique<LinkBuffer>(
vm, exitThunkGenerator, codeBlock, JITCompilationMustSucceed);
RELEASE_ASSERT(state.finalizer->osrExit.size() == state.jitCode->osrExit.size());
for (unsigned i = 0; i < state.jitCode->osrExit.size(); ++i) {
OSRExitCompilationInfo& info = state.finalizer->osrExit[i];
OSRExit& exit = jitCode->osrExit[i];
if (verboseCompilationEnabled())
dataLog("Handling OSR stackmap #", exit.m_stackmapID, " for ", exit.m_codeOrigin, "\n");
auto iter = recordMap.find(exit.m_stackmapID);
if (iter == recordMap.end()) {
// It was optimized out.
continue;
}
info.m_thunkAddress = linkBuffer->locationOf(info.m_thunkLabel);
exit.m_patchableCodeOffset = linkBuffer->offsetOf(info.m_thunkJump);
for (unsigned j = exit.m_values.size(); j--;) {
ExitValue value = exit.m_values[j];
if (!value.isInJSStackSomehow())
continue;
if (!value.virtualRegister().isLocal())
continue;
exit.m_values[j] = value.withVirtualRegister(
VirtualRegister(value.virtualRegister().offset() + localsOffset));
}
if (verboseCompilationEnabled()) {
DumpContext context;
dataLog(" Exit values: ", inContext(exit.m_values, &context), "\n");
}
}
state.finalizer->exitThunksLinkBuffer = WTF::move(linkBuffer);
}
if (!state.getByIds.isEmpty() || !state.putByIds.isEmpty() || !state.checkIns.isEmpty()) {
CCallHelpers slowPathJIT(&vm, codeBlock);
CCallHelpers::JumpList exceptionTarget;
for (unsigned i = state.getByIds.size(); i--;) {
GetByIdDescriptor& getById = state.getByIds[i];
if (verboseCompilationEnabled())
dataLog("Handling GetById stackmap #", getById.stackmapID(), "\n");
auto iter = recordMap.find(getById.stackmapID());
if (iter == recordMap.end()) {
// It was optimized out.
continue;
}
for (unsigned i = 0; i < iter->value.size(); ++i) {
StackMaps::Record& record = iter->value[i];
RegisterSet usedRegisters = usedRegistersFor(record);
GPRReg result = record.locations[0].directGPR();
GPRReg base = record.locations[1].directGPR();
JITGetByIdGenerator gen(
codeBlock, getById.codeOrigin(), usedRegisters, JSValueRegs(base),
JSValueRegs(result), NeedToSpill);
MacroAssembler::Label begin = slowPathJIT.label();
MacroAssembler::Call call = callOperation(
state, usedRegisters, slowPathJIT, getById.codeOrigin(), &exceptionTarget,
operationGetByIdOptimize, result, gen.stubInfo(), base, getById.uid());
gen.reportSlowPathCall(begin, call);
getById.m_slowPathDone.append(slowPathJIT.jump());
getById.m_generators.append(gen);
}
}
for (unsigned i = state.putByIds.size(); i--;) {
PutByIdDescriptor& putById = state.putByIds[i];
if (verboseCompilationEnabled())
dataLog("Handling PutById stackmap #", putById.stackmapID(), "\n");
auto iter = recordMap.find(putById.stackmapID());
if (iter == recordMap.end()) {
// It was optimized out.
continue;
}
for (unsigned i = 0; i < iter->value.size(); ++i) {
StackMaps::Record& record = iter->value[i];
RegisterSet usedRegisters = usedRegistersFor(record);
GPRReg base = record.locations[0].directGPR();
GPRReg value = record.locations[1].directGPR();
JITPutByIdGenerator gen(
codeBlock, putById.codeOrigin(), usedRegisters, JSValueRegs(base),
JSValueRegs(value), GPRInfo::patchpointScratchRegister, NeedToSpill,
putById.ecmaMode(), putById.putKind());
MacroAssembler::Label begin = slowPathJIT.label();
MacroAssembler::Call call = callOperation(
state, usedRegisters, slowPathJIT, putById.codeOrigin(), &exceptionTarget,
gen.slowPathFunction(), gen.stubInfo(), value, base, putById.uid());
gen.reportSlowPathCall(begin, call);
putById.m_slowPathDone.append(slowPathJIT.jump());
putById.m_generators.append(gen);
}
}
for (unsigned i = state.checkIns.size(); i--;) {
CheckInDescriptor& checkIn = state.checkIns[i];
if (verboseCompilationEnabled())
dataLog("Handling checkIn stackmap #", checkIn.stackmapID(), "\n");
auto iter = recordMap.find(checkIn.stackmapID());
if (iter == recordMap.end()) {
// It was optimized out.
continue;
}
for (unsigned i = 0; i < iter->value.size(); ++i) {
StackMaps::Record& record = iter->value[i];
RegisterSet usedRegisters = usedRegistersFor(record);
GPRReg result = record.locations[0].directGPR();
GPRReg obj = record.locations[1].directGPR();
StructureStubInfo* stubInfo = codeBlock->addStubInfo();
stubInfo->codeOrigin = checkIn.codeOrigin();
stubInfo->patch.baseGPR = static_cast<int8_t>(obj);
stubInfo->patch.valueGPR = static_cast<int8_t>(result);
stubInfo->patch.usedRegisters = usedRegisters;
stubInfo->patch.spillMode = NeedToSpill;
MacroAssembler::Label begin = slowPathJIT.label();
MacroAssembler::Call slowCall = callOperation(
state, usedRegisters, slowPathJIT, checkIn.codeOrigin(), &exceptionTarget,
operationInOptimize, result, stubInfo, obj, checkIn.m_id);
checkIn.m_slowPathDone.append(slowPathJIT.jump());
checkIn.m_generators.append(CheckInGenerator(stubInfo, slowCall, begin));
}
}
exceptionTarget.link(&slowPathJIT);
MacroAssembler::Jump exceptionJump = slowPathJIT.jump();
state.finalizer->sideCodeLinkBuffer = std::make_unique<LinkBuffer>(vm, slowPathJIT, codeBlock, JITCompilationMustSucceed);
state.finalizer->sideCodeLinkBuffer->link(
exceptionJump, state.finalizer->handleExceptionsLinkBuffer->entrypoint());
for (unsigned i = state.getByIds.size(); i--;) {
generateICFastPath(
state, codeBlock, generatedFunction, recordMap, state.getByIds[i],
sizeOfGetById());
}
for (unsigned i = state.putByIds.size(); i--;) {
generateICFastPath(
state, codeBlock, generatedFunction, recordMap, state.putByIds[i],
sizeOfPutById());
}
for (unsigned i = state.checkIns.size(); i--;) {
generateCheckInICFastPath(
state, codeBlock, generatedFunction, recordMap, state.checkIns[i],
sizeOfIn());
}
}
adjustCallICsForStackmaps(state.jsCalls, recordMap);
for (unsigned i = state.jsCalls.size(); i--;) {
JSCall& call = state.jsCalls[i];
CCallHelpers fastPathJIT(&vm, codeBlock);
call.emit(fastPathJIT);
char* startOfIC = bitwise_cast<char*>(generatedFunction) + call.m_instructionOffset;
LinkBuffer linkBuffer(vm, fastPathJIT, startOfIC, sizeOfCall());
if (!linkBuffer.isValid()) {
dataLog("Failed to insert inline cache for call because we thought the size would be ", sizeOfCall(), " but it ended up being ", fastPathJIT.m_assembler.codeSize(), " prior to compaction.\n");
RELEASE_ASSERT_NOT_REACHED();
}
MacroAssembler::AssemblerType_T::fillNops(
startOfIC + linkBuffer.size(), sizeOfCall() - linkBuffer.size());
call.link(vm, linkBuffer);
}
adjustCallICsForStackmaps(state.jsCallVarargses, recordMap);
for (unsigned i = state.jsCallVarargses.size(); i--;) {
JSCallVarargs& call = state.jsCallVarargses[i];
CCallHelpers fastPathJIT(&vm, codeBlock);
call.emit(fastPathJIT, graph, varargsSpillSlotsOffset);
char* startOfIC = bitwise_cast<char*>(generatedFunction) + call.m_instructionOffset;
size_t sizeOfIC = sizeOfICFor(call.node());
LinkBuffer linkBuffer(vm, fastPathJIT, startOfIC, sizeOfIC);
if (!linkBuffer.isValid()) {
dataLog("Failed to insert inline cache for varargs call (specifically, ", Graph::opName(call.node()->op()), ") because we thought the size would be ", sizeOfIC, " but it ended up being ", fastPathJIT.m_assembler.codeSize(), " prior to compaction.\n");
RELEASE_ASSERT_NOT_REACHED();
}
MacroAssembler::AssemblerType_T::fillNops(
startOfIC + linkBuffer.size(), sizeOfIC - linkBuffer.size());
call.link(vm, linkBuffer, state.finalizer->handleExceptionsLinkBuffer->entrypoint());
}
RepatchBuffer repatchBuffer(codeBlock);
auto iter = recordMap.find(state.handleStackOverflowExceptionStackmapID);
// It's sort of remotely possible that we won't have an in-band exception handling
// path, for some kinds of functions.
if (iter != recordMap.end()) {
for (unsigned i = iter->value.size(); i--;) {
StackMaps::Record& record = iter->value[i];
CodeLocationLabel source = CodeLocationLabel(
bitwise_cast<char*>(generatedFunction) + record.instructionOffset);
RELEASE_ASSERT(stackOverflowException.isSet());
repatchBuffer.replaceWithJump(source, state.finalizer->handleExceptionsLinkBuffer->locationOf(stackOverflowException));
}
}
iter = recordMap.find(state.handleExceptionStackmapID);
// It's sort of remotely possible that we won't have an in-band exception handling
// path, for some kinds of functions.
if (iter != recordMap.end()) {
for (unsigned i = iter->value.size(); i--;) {
StackMaps::Record& record = iter->value[i];
CodeLocationLabel source = CodeLocationLabel(
bitwise_cast<char*>(generatedFunction) + record.instructionOffset);
repatchBuffer.replaceWithJump(source, state.finalizer->handleExceptionsLinkBuffer->entrypoint());
}
}
for (unsigned exitIndex = 0; exitIndex < jitCode->osrExit.size(); ++exitIndex) {
OSRExitCompilationInfo& info = state.finalizer->osrExit[exitIndex];
OSRExit& exit = jitCode->osrExit[exitIndex];
iter = recordMap.find(exit.m_stackmapID);
Vector<const void*> codeAddresses;
if (iter != recordMap.end()) {
for (unsigned i = iter->value.size(); i--;) {
StackMaps::Record& record = iter->value[i];
CodeLocationLabel source = CodeLocationLabel(
bitwise_cast<char*>(generatedFunction) + record.instructionOffset);
codeAddresses.append(bitwise_cast<char*>(generatedFunction) + record.instructionOffset + MacroAssembler::maxJumpReplacementSize());
if (info.m_isInvalidationPoint)
jitCode->common.jumpReplacements.append(JumpReplacement(source, info.m_thunkAddress));
else
repatchBuffer.replaceWithJump(source, info.m_thunkAddress);
}
}
if (graph.compilation())
graph.compilation()->addOSRExitSite(codeAddresses);
}
}
bool JITCompiler::compileFunction(JITCode& entry, MacroAssemblerCodePtr& entryWithArityCheck)
{
SamplingRegion samplingRegion("DFG Backend");
setStartOfCode();
compileEntry();
// === Function header code generation ===
// This is the main entry point, without performing an arity check.
// If we needed to perform an arity check we will already have moved the return address,
// so enter after this.
Label fromArityCheck(this);
// Plant a check that sufficient space is available in the JSStack.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=56291
addPtr(TrustedImm32(m_codeBlock->m_numCalleeRegisters * sizeof(Register)), GPRInfo::callFrameRegister, GPRInfo::regT1);
Jump stackCheck = branchPtr(Below, AbsoluteAddress(m_vm->interpreter->stack().addressOfEnd()), GPRInfo::regT1);
// Return here after stack check.
Label fromStackCheck = label();
// === Function body code generation ===
SpeculativeJIT speculative(*this);
compileBody(speculative);
setEndOfMainPath();
// === Function footer code generation ===
//
// Generate code to perform the slow stack check (if the fast one in
// the function header fails), and generate the entry point with arity check.
//
// Generate the stack check; if the fast check in the function head fails,
// we need to call out to a helper function to check whether more space is available.
// FIXME: change this from a cti call to a DFG style operation (normal C calling conventions).
stackCheck.link(this);
move(stackPointerRegister, GPRInfo::argumentGPR0);
poke(GPRInfo::callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
CallBeginToken token;
beginCall(CodeOrigin(0), token);
Call callStackCheck = call();
notifyCall(callStackCheck, CodeOrigin(0), token);
jump(fromStackCheck);
// The fast entry point into a function does not check the correct number of arguments
// have been passed to the call (we only use the fast entry point where we can statically
// determine the correct number of arguments have been passed, or have already checked).
// In cases where an arity check is necessary, we enter here.
// FIXME: change this from a cti call to a DFG style operation (normal C calling conventions).
Label arityCheck = label();
compileEntry();
load32(AssemblyHelpers::payloadFor((VirtualRegister)JSStack::ArgumentCount), GPRInfo::regT1);
branch32(AboveOrEqual, GPRInfo::regT1, TrustedImm32(m_codeBlock->numParameters())).linkTo(fromArityCheck, this);
move(stackPointerRegister, GPRInfo::argumentGPR0);
poke(GPRInfo::callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
beginCall(CodeOrigin(0), token);
Call callArityCheck = call();
notifyCall(callArityCheck, CodeOrigin(0), token);
move(GPRInfo::regT0, GPRInfo::callFrameRegister);
jump(fromArityCheck);
// Generate slow path code.
speculative.runSlowPathGenerators();
compileExceptionHandlers();
linkOSRExits();
// Create OSR entry trampolines if necessary.
speculative.createOSREntries();
setEndOfCode();
// === Link ===
LinkBuffer linkBuffer(*m_vm, this, m_codeBlock, JITCompilationCanFail);
if (linkBuffer.didFailToAllocate())
return false;
link(linkBuffer);
speculative.linkOSREntries(linkBuffer);
// FIXME: switch the stack check & arity check over to DFGOpertaion style calls, not JIT stubs.
linkBuffer.link(callStackCheck, cti_stack_check);
linkBuffer.link(callArityCheck, m_codeBlock->m_isConstructor ? cti_op_construct_arityCheck : cti_op_call_arityCheck);
if (shouldShowDisassembly())
m_disassembler->dump(linkBuffer);
if (m_graph.m_compilation)
m_disassembler->reportToProfiler(m_graph.m_compilation.get(), linkBuffer);
entryWithArityCheck = linkBuffer.locationOf(arityCheck);
entry = JITCode(
linkBuffer.finalizeCodeWithoutDisassembly(),
JITCode::DFGJIT);
return true;
}
MacroAssemblerCodeRef generateRegisterPreservationWrapper(VM& vm, ExecutableBase* executable, MacroAssemblerCodePtr target)
{
#if ENABLE(FTL_JIT)
// We shouldn't ever be generating wrappers for native functions.
RegisterSet toSave = registersToPreserve();
ptrdiff_t offset = registerPreservationOffset();
AssemblyHelpers jit(&vm, 0);
jit.preserveReturnAddressAfterCall(GPRInfo::regT1);
jit.load32(
AssemblyHelpers::Address(
AssemblyHelpers::stackPointerRegister,
(JSStack::ArgumentCount - JSStack::CallerFrameAndPCSize) * sizeof(Register) + PayloadOffset),
GPRInfo::regT2);
// Place the stack pointer where we want it to be.
jit.subPtr(AssemblyHelpers::TrustedImm32(offset), AssemblyHelpers::stackPointerRegister);
// Compute the number of things we will be copying.
jit.add32(
AssemblyHelpers::TrustedImm32(
JSStack::CallFrameHeaderSize - JSStack::CallerFrameAndPCSize),
GPRInfo::regT2);
ASSERT(!toSave.get(GPRInfo::regT4));
jit.move(AssemblyHelpers::stackPointerRegister, GPRInfo::regT4);
AssemblyHelpers::Label loop = jit.label();
jit.sub32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
jit.load64(AssemblyHelpers::Address(GPRInfo::regT4, offset), GPRInfo::regT0);
jit.store64(GPRInfo::regT0, GPRInfo::regT4);
jit.addPtr(AssemblyHelpers::TrustedImm32(sizeof(Register)), GPRInfo::regT4);
jit.branchTest32(AssemblyHelpers::NonZero, GPRInfo::regT2).linkTo(loop, &jit);
// At this point regT4 + offset points to where we save things.
ptrdiff_t currentOffset = 0;
jit.storePtr(GPRInfo::regT1, AssemblyHelpers::Address(GPRInfo::regT4, currentOffset));
for (GPRReg gpr = AssemblyHelpers::firstRegister(); gpr <= AssemblyHelpers::lastRegister(); gpr = static_cast<GPRReg>(gpr + 1)) {
if (!toSave.get(gpr))
continue;
currentOffset += sizeof(Register);
jit.store64(gpr, AssemblyHelpers::Address(GPRInfo::regT4, currentOffset));
}
// Assume that there aren't any saved FP registers.
// Restore the tag registers.
jit.move(AssemblyHelpers::TrustedImm64(TagTypeNumber), GPRInfo::tagTypeNumberRegister);
jit.add64(AssemblyHelpers::TrustedImm32(TagMask - TagTypeNumber), GPRInfo::tagTypeNumberRegister, GPRInfo::tagMaskRegister);
jit.move(
AssemblyHelpers::TrustedImmPtr(
vm.getCTIStub(registerRestorationThunkGenerator).code().executableAddress()),
GPRInfo::nonArgGPR0);
jit.restoreReturnAddressBeforeReturn(GPRInfo::nonArgGPR0);
AssemblyHelpers::Jump jump = jit.jump();
LinkBuffer linkBuffer(vm, &jit, GLOBAL_THUNK_ID);
linkBuffer.link(jump, CodeLocationLabel(target));
if (Options::verboseFTLToJSThunk())
dataLog("Need a thunk for calls from FTL to non-FTL version of ", *executable, "\n");
return FINALIZE_DFG_CODE(linkBuffer, ("Register preservation wrapper for %s/%s, %p", toCString(executable->hashFor(CodeForCall)).data(), toCString(executable->hashFor(CodeForConstruct)).data(), target.executableAddress()));
#else // ENABLE(FTL_JIT)
UNUSED_PARAM(vm);
UNUSED_PARAM(executable);
UNUSED_PARAM(target);
// We don't support non-FTL builds for two reasons:
// - It just so happens that currently only the FTL bottoms out in this code.
// - The code above uses 64-bit instructions. It doesn't necessarily have to; it would be
// easy to change it so that it doesn't. But obviously making that change would be a
// prerequisite to removing this #if.
UNREACHABLE_FOR_PLATFORM();
return MacroAssemblerCodeRef();
#endif // ENABLE(FTL_JIT)
}
// We are creating a bunch of threads that touch the main thread's stack. This will make ASAN unhappy.
// The reason this is OK is that we guarantee that the main thread doesn't continue until all threads
// that could touch its stack are done executing.
SUPPRESS_ASAN
void Plan::run()
{
if (!parseAndValidateModule())
return;
auto tryReserveCapacity = [this] (auto& vector, size_t size, const char* what) {
if (UNLIKELY(!vector.tryReserveCapacity(size))) {
StringBuilder builder;
builder.appendLiteral("Failed allocating enough space for ");
builder.appendNumber(size);
builder.append(what);
m_errorMessage = builder.toString();
return false;
}
return true;
};
if (!tryReserveCapacity(m_wasmExitStubs, m_moduleInformation->importFunctionSignatureIndices.size(), " WebAssembly to JavaScript stubs")
|| !tryReserveCapacity(m_unlinkedWasmToWasmCalls, m_functionLocationInBinary.size(), " unlinked WebAssembly to WebAssembly calls")
|| !tryReserveCapacity(m_wasmInternalFunctions, m_functionLocationInBinary.size(), " WebAssembly functions")
|| !tryReserveCapacity(m_compilationContexts, m_functionLocationInBinary.size(), " compilation contexts"))
return;
m_unlinkedWasmToWasmCalls.resize(m_functionLocationInBinary.size());
m_wasmInternalFunctions.resize(m_functionLocationInBinary.size());
m_compilationContexts.resize(m_functionLocationInBinary.size());
for (unsigned importIndex = 0; importIndex < m_moduleInformation->imports.size(); ++importIndex) {
Import* import = &m_moduleInformation->imports[importIndex];
if (import->kind != ExternalKind::Function)
continue;
unsigned importFunctionIndex = m_wasmExitStubs.size();
if (verbose)
dataLogLn("Processing import function number ", importFunctionIndex, ": ", import->module, ": ", import->field);
SignatureIndex signatureIndex = m_moduleInformation->importFunctionSignatureIndices.at(import->kindIndex);
m_wasmExitStubs.uncheckedAppend(exitStubGenerator(m_vm, m_callLinkInfos, signatureIndex, importFunctionIndex));
}
m_currentIndex = 0;
auto doWork = [this] {
while (true) {
uint32_t functionIndex;
{
auto locker = holdLock(m_lock);
if (m_currentIndex >= m_functionLocationInBinary.size())
return;
functionIndex = m_currentIndex;
++m_currentIndex;
}
const uint8_t* functionStart = m_source + m_functionLocationInBinary[functionIndex].start;
size_t functionLength = m_functionLocationInBinary[functionIndex].end - m_functionLocationInBinary[functionIndex].start;
ASSERT(functionLength <= m_sourceLength);
SignatureIndex signatureIndex = m_moduleInformation->internalFunctionSignatureIndices[functionIndex];
const Signature* signature = SignatureInformation::get(m_vm, signatureIndex);
unsigned functionIndexSpace = m_wasmExitStubs.size() + functionIndex;
ASSERT_UNUSED(functionIndexSpace, m_moduleInformation->signatureIndexFromFunctionIndexSpace(functionIndexSpace) == signatureIndex);
ASSERT(validateFunction(m_vm, functionStart, functionLength, signature, *m_moduleInformation, m_moduleSignatureIndicesToUniquedSignatureIndices));
m_unlinkedWasmToWasmCalls[functionIndex] = Vector<UnlinkedWasmToWasmCall>();
auto parseAndCompileResult = parseAndCompile(*m_vm, m_compilationContexts[functionIndex], functionStart, functionLength, signature, m_unlinkedWasmToWasmCalls[functionIndex], *m_moduleInformation, m_moduleSignatureIndicesToUniquedSignatureIndices);
if (UNLIKELY(!parseAndCompileResult)) {
auto locker = holdLock(m_lock);
if (!m_errorMessage) {
// Multiple compiles could fail simultaneously. We arbitrarily choose the first.
m_errorMessage = makeString(parseAndCompileResult.error(), ", in function at index ", String::number(functionIndex)); // FIXME make this an Expected.
}
m_currentIndex = m_functionLocationInBinary.size();
// We will terminate on the next execution.
continue;
}
m_wasmInternalFunctions[functionIndex] = WTFMove(*parseAndCompileResult);
}
};
MonotonicTime startTime;
if (verbose || Options::reportCompileTimes())
startTime = MonotonicTime::now();
uint32_t threadCount = Options::useConcurrentJIT() ? WTF::numberOfProcessorCores() : 1;
uint32_t numWorkerThreads = threadCount - 1;
Vector<ThreadIdentifier> threads;
threads.reserveCapacity(numWorkerThreads);
for (uint32_t i = 0; i < numWorkerThreads; i++)
threads.uncheckedAppend(createThread("jsc.wasm-b3-compilation.thread", doWork));
doWork(); // Let the main thread do some work too.
for (uint32_t i = 0; i < numWorkerThreads; i++)
waitForThreadCompletion(threads[i]);
for (uint32_t functionIndex = 0; functionIndex < m_functionLocationInBinary.size(); functionIndex++) {
{
CompilationContext& context = m_compilationContexts[functionIndex];
SignatureIndex signatureIndex = m_moduleInformation->internalFunctionSignatureIndices[functionIndex];
String signatureDescription = SignatureInformation::get(m_vm, signatureIndex)->toString();
{
LinkBuffer linkBuffer(*m_vm, *context.wasmEntrypointJIT, nullptr);
m_wasmInternalFunctions[functionIndex]->wasmEntrypoint.compilation =
std::make_unique<B3::Compilation>(FINALIZE_CODE(linkBuffer, ("WebAssembly function[%i] %s", functionIndex, signatureDescription.ascii().data())), WTFMove(context.wasmEntrypointByproducts));
}
{
LinkBuffer linkBuffer(*m_vm, *context.jsEntrypointJIT, nullptr);
linkBuffer.link(context.jsEntrypointToWasmEntrypointCall, FunctionPtr(m_wasmInternalFunctions[functionIndex]->wasmEntrypoint.compilation->code().executableAddress()));
m_wasmInternalFunctions[functionIndex]->jsToWasmEntrypoint.compilation =
std::make_unique<B3::Compilation>(FINALIZE_CODE(linkBuffer, ("JavaScript->WebAssembly entrypoint[%i] %s", functionIndex, signatureDescription.ascii().data())), WTFMove(context.jsEntrypointByproducts));
}
}
}
if (verbose || Options::reportCompileTimes()) {
dataLogLn("Took ", (MonotonicTime::now() - startTime).microseconds(),
" us to compile and link the module");
}
// Patch the call sites for each WebAssembly function.
for (auto& unlinked : m_unlinkedWasmToWasmCalls) {
for (auto& call : unlinked) {
void* executableAddress;
if (m_moduleInformation->isImportedFunctionFromFunctionIndexSpace(call.functionIndex)) {
// FIXME imports could have been linked in B3, instead of generating a patchpoint. This condition should be replaced by a RELEASE_ASSERT. https://bugs.webkit.org/show_bug.cgi?id=166462
executableAddress = call.target == UnlinkedWasmToWasmCall::Target::ToJs
? m_wasmExitStubs.at(call.functionIndex).wasmToJs.code().executableAddress()
: m_wasmExitStubs.at(call.functionIndex).wasmToWasm.code().executableAddress();
} else {
ASSERT(call.target != UnlinkedWasmToWasmCall::Target::ToJs);
executableAddress = m_wasmInternalFunctions.at(call.functionIndex - m_wasmExitStubs.size())->wasmEntrypoint.compilation->code().executableAddress();
}
MacroAssembler::repatchCall(call.callLocation, CodeLocationLabel(executableAddress));
}
}
m_failed = false;
}
CodeLocationLabel* ArityCheckFailReturnThunks::returnPCsFor(
VM& vm, unsigned numExpectedArgumentsIncludingThis)
{
ASSERT(numExpectedArgumentsIncludingThis >= 1);
numExpectedArgumentsIncludingThis = WTF::roundUpToMultipleOf(
stackAlignmentRegisters(), numExpectedArgumentsIncludingThis);
{
ConcurrentJITLocker locker(m_lock);
if (numExpectedArgumentsIncludingThis < m_nextSize)
return m_returnPCArrays.last().get();
}
ASSERT(!isCompilationThread());
numExpectedArgumentsIncludingThis = std::max(numExpectedArgumentsIncludingThis, m_nextSize * 2);
AssemblyHelpers jit(&vm, 0);
Vector<AssemblyHelpers::Label> labels;
for (unsigned size = m_nextSize; size <= numExpectedArgumentsIncludingThis; size += stackAlignmentRegisters()) {
labels.append(jit.label());
jit.load32(
AssemblyHelpers::Address(
AssemblyHelpers::stackPointerRegister,
(JSStack::ArgumentCount - JSStack::CallerFrameAndPCSize) * sizeof(Register) +
PayloadOffset),
GPRInfo::regT4);
jit.add32(
AssemblyHelpers::TrustedImm32(
JSStack::CallFrameHeaderSize - JSStack::CallerFrameAndPCSize + size - 1),
GPRInfo::regT4, GPRInfo::regT2);
jit.lshift32(AssemblyHelpers::TrustedImm32(3), GPRInfo::regT2);
jit.addPtr(AssemblyHelpers::stackPointerRegister, GPRInfo::regT2);
jit.loadPtr(GPRInfo::regT2, GPRInfo::regT2);
jit.addPtr(
AssemblyHelpers::TrustedImm32(size * sizeof(Register)),
AssemblyHelpers::stackPointerRegister);
// Thunks like ours want to use the return PC to figure out where things
// were saved. So, we pay it forward.
jit.store32(
GPRInfo::regT4,
AssemblyHelpers::Address(
AssemblyHelpers::stackPointerRegister,
(JSStack::ArgumentCount - JSStack::CallerFrameAndPCSize) * sizeof(Register) +
PayloadOffset));
jit.jump(GPRInfo::regT2);
}
LinkBuffer linkBuffer(vm, &jit, GLOBAL_THUNK_ID);
unsigned returnPCsSize = numExpectedArgumentsIncludingThis / stackAlignmentRegisters() + 1;
std::unique_ptr<CodeLocationLabel[]> returnPCs =
std::make_unique<CodeLocationLabel[]>(returnPCsSize);
for (unsigned size = 0; size <= numExpectedArgumentsIncludingThis; size += stackAlignmentRegisters()) {
unsigned index = size / stackAlignmentRegisters();
RELEASE_ASSERT(index < returnPCsSize);
if (size < m_nextSize)
returnPCs[index] = m_returnPCArrays.last()[index];
else
returnPCs[index] = linkBuffer.locationOf(labels[(size - m_nextSize) / stackAlignmentRegisters()]);
}
CodeLocationLabel* result = returnPCs.get();
{
ConcurrentJITLocker locker(m_lock);
m_returnPCArrays.append(std::move(returnPCs));
m_refs.append(FINALIZE_CODE(linkBuffer, ("Arity check fail return thunks for up to numArgs = %u", numExpectedArgumentsIncludingThis)));
m_nextSize = numExpectedArgumentsIncludingThis + stackAlignmentRegisters();
}
return result;
}
void JITCompiler::compileFunction(JITCode& entry, MacroAssemblerCodePtr& entryWithArityCheck)
{
compileEntry();
// === Function header code generation ===
// This is the main entry point, without performing an arity check.
// If we needed to perform an arity check we will already have moved the return address,
// so enter after this.
Label fromArityCheck(this);
// Plant a check that sufficient space is available in the RegisterFile.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=56291
addPtr(Imm32(m_codeBlock->m_numCalleeRegisters * sizeof(Register)), GPRInfo::callFrameRegister, GPRInfo::regT1);
Jump registerFileCheck = branchPtr(Below, AbsoluteAddress(m_globalData->interpreter->registerFile().addressOfEnd()), GPRInfo::regT1);
// Return here after register file check.
Label fromRegisterFileCheck = label();
// === Function body code generation ===
SpeculativeJIT speculative(*this);
compileBody(speculative);
// === Function footer code generation ===
//
// Generate code to perform the slow register file check (if the fast one in
// the function header fails), and generate the entry point with arity check.
//
// Generate the register file check; if the fast check in the function head fails,
// we need to call out to a helper function to check whether more space is available.
// FIXME: change this from a cti call to a DFG style operation (normal C calling conventions).
registerFileCheck.link(this);
move(stackPointerRegister, GPRInfo::argumentGPR0);
poke(GPRInfo::callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
Call callRegisterFileCheck = call();
jump(fromRegisterFileCheck);
// The fast entry point into a function does not check the correct number of arguments
// have been passed to the call (we only use the fast entry point where we can statically
// determine the correct number of arguments have been passed, or have already checked).
// In cases where an arity check is necessary, we enter here.
// FIXME: change this from a cti call to a DFG style operation (normal C calling conventions).
Label arityCheck = label();
compileEntry();
load32(Address(GPRInfo::callFrameRegister, RegisterFile::ArgumentCount * static_cast<int>(sizeof(Register))), GPRInfo::regT1);
branch32(Equal, GPRInfo::regT1, Imm32(m_codeBlock->m_numParameters)).linkTo(fromArityCheck, this);
move(stackPointerRegister, GPRInfo::argumentGPR0);
poke(GPRInfo::callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
Call callArityCheck = call();
move(GPRInfo::regT0, GPRInfo::callFrameRegister);
jump(fromArityCheck);
// === Link ===
LinkBuffer linkBuffer(*m_globalData, this);
link(linkBuffer);
speculative.linkOSREntries(linkBuffer);
// FIXME: switch the register file check & arity check over to DFGOpertaion style calls, not JIT stubs.
linkBuffer.link(callRegisterFileCheck, cti_register_file_check);
linkBuffer.link(callArityCheck, m_codeBlock->m_isConstructor ? cti_op_construct_arityCheck : cti_op_call_arityCheck);
entryWithArityCheck = linkBuffer.locationOf(arityCheck);
entry = JITCode(linkBuffer.finalizeCode(), JITCode::DFGJIT);
}