CCallHelpers::JumpList generateImpl(AccessGenerationState& state, const RegisterSet& usedRegistersBySnippet, CCallHelpers& jit, std::index_sequence<ArgumentsIndex...>)
{
CCallHelpers::JumpList exceptions;
// We spill (1) the used registers by IC and (2) the used registers by Snippet.
AccessGenerationState::SpillState spillState = state.preserveLiveRegistersToStackForCall(usedRegistersBySnippet);
jit.store32(
CCallHelpers::TrustedImm32(state.callSiteIndexForExceptionHandlingOrOriginal().bits()),
CCallHelpers::tagFor(static_cast<VirtualRegister>(CallFrameSlot::argumentCount)));
jit.makeSpaceOnStackForCCall();
jit.setupArguments<FunctionType>(std::get<ArgumentsIndex>(m_arguments)...);
CCallHelpers::Call operationCall = jit.call(OperationPtrTag);
auto function = m_function;
jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
linkBuffer.link(operationCall, FunctionPtr<OperationPtrTag>(function));
});
jit.setupResults(m_result);
jit.reclaimSpaceOnStackForCCall();
CCallHelpers::Jump noException = jit.emitExceptionCheck(state.m_vm, CCallHelpers::InvertedExceptionCheck);
state.restoreLiveRegistersFromStackForCallWithThrownException(spillState);
exceptions.append(jit.jump());
noException.link(&jit);
RegisterSet dontRestore;
dontRestore.set(m_result);
state.restoreLiveRegistersFromStackForCall(spillState, dontRestore);
return exceptions;
}
void GetterSetterAccessCase::emitDOMJITGetter(AccessGenerationState& state, const DOMJIT::GetterSetter* domJIT, GPRReg baseForGetGPR)
{
CCallHelpers& jit = *state.jit;
StructureStubInfo& stubInfo = *state.stubInfo;
JSValueRegs valueRegs = state.valueRegs;
GPRReg baseGPR = state.baseGPR;
GPRReg scratchGPR = state.scratchGPR;
// We construct the environment that can execute the DOMJIT::Snippet here.
Ref<DOMJIT::CallDOMGetterSnippet> snippet = domJIT->compiler()();
Vector<GPRReg> gpScratch;
Vector<FPRReg> fpScratch;
Vector<SnippetParams::Value> regs;
ScratchRegisterAllocator allocator(stubInfo.patch.usedRegisters);
allocator.lock(baseGPR);
#if USE(JSVALUE32_64)
allocator.lock(static_cast<GPRReg>(stubInfo.patch.baseTagGPR));
#endif
allocator.lock(valueRegs);
allocator.lock(scratchGPR);
GPRReg paramBaseGPR = InvalidGPRReg;
GPRReg paramGlobalObjectGPR = InvalidGPRReg;
JSValueRegs paramValueRegs = valueRegs;
GPRReg remainingScratchGPR = InvalidGPRReg;
// valueRegs and baseForGetGPR may be the same. For example, in Baseline JIT, we pass the same regT0 for baseGPR and valueRegs.
// In FTL, there is no constraint that the baseForGetGPR interferes with the result. To make implementation simple in
// Snippet, Snippet assumes that result registers always early interfere with input registers, in this case,
// baseForGetGPR. So we move baseForGetGPR to the other register if baseForGetGPR == valueRegs.
if (baseForGetGPR != valueRegs.payloadGPR()) {
paramBaseGPR = baseForGetGPR;
if (!snippet->requireGlobalObject)
remainingScratchGPR = scratchGPR;
else
paramGlobalObjectGPR = scratchGPR;
} else {
jit.move(valueRegs.payloadGPR(), scratchGPR);
paramBaseGPR = scratchGPR;
if (snippet->requireGlobalObject)
paramGlobalObjectGPR = allocator.allocateScratchGPR();
}
JSGlobalObject* globalObjectForDOMJIT = structure()->globalObject();
regs.append(paramValueRegs);
regs.append(paramBaseGPR);
if (snippet->requireGlobalObject) {
ASSERT(paramGlobalObjectGPR != InvalidGPRReg);
regs.append(SnippetParams::Value(paramGlobalObjectGPR, globalObjectForDOMJIT));
}
if (snippet->numGPScratchRegisters) {
unsigned i = 0;
if (remainingScratchGPR != InvalidGPRReg) {
gpScratch.append(remainingScratchGPR);
++i;
}
for (; i < snippet->numGPScratchRegisters; ++i)
gpScratch.append(allocator.allocateScratchGPR());
}
for (unsigned i = 0; i < snippet->numFPScratchRegisters; ++i)
fpScratch.append(allocator.allocateScratchFPR());
// Let's store the reused registers to the stack. After that, we can use allocated scratch registers.
ScratchRegisterAllocator::PreservedState preservedState =
allocator.preserveReusedRegistersByPushing(jit, ScratchRegisterAllocator::ExtraStackSpace::SpaceForCCall);
if (verbose) {
dataLog("baseGPR = ", baseGPR, "\n");
dataLog("valueRegs = ", valueRegs, "\n");
dataLog("scratchGPR = ", scratchGPR, "\n");
dataLog("paramBaseGPR = ", paramBaseGPR, "\n");
if (paramGlobalObjectGPR != InvalidGPRReg)
dataLog("paramGlobalObjectGPR = ", paramGlobalObjectGPR, "\n");
dataLog("paramValueRegs = ", paramValueRegs, "\n");
for (unsigned i = 0; i < snippet->numGPScratchRegisters; ++i)
dataLog("gpScratch[", i, "] = ", gpScratch[i], "\n");
}
if (snippet->requireGlobalObject)
jit.move(CCallHelpers::TrustedImmPtr(globalObjectForDOMJIT), paramGlobalObjectGPR);
// We just spill the registers used in Snippet here. For not spilled registers here explicitly,
// they must be in the used register set passed by the callers (Baseline, DFG, and FTL) if they need to be kept.
// Some registers can be locked, but not in the used register set. For example, the caller could make baseGPR
// same to valueRegs, and not include it in the used registers since it will be changed.
RegisterSet registersToSpillForCCall;
for (auto& value : regs) {
SnippetReg reg = value.reg();
if (reg.isJSValueRegs())
registersToSpillForCCall.set(reg.jsValueRegs());
else if (reg.isGPR())
registersToSpillForCCall.set(reg.gpr());
else
registersToSpillForCCall.set(reg.fpr());
}
for (GPRReg reg : gpScratch)
registersToSpillForCCall.set(reg);
for (FPRReg reg : fpScratch)
registersToSpillForCCall.set(reg);
registersToSpillForCCall.exclude(RegisterSet::registersToNotSaveForCCall());
AccessCaseSnippetParams params(state.m_vm, WTFMove(regs), WTFMove(gpScratch), WTFMove(fpScratch));
snippet->generator()->run(jit, params);
allocator.restoreReusedRegistersByPopping(jit, preservedState);
state.succeed();
CCallHelpers::JumpList exceptions = params.emitSlowPathCalls(state, registersToSpillForCCall, jit);
if (!exceptions.empty()) {
exceptions.link(&jit);
allocator.restoreReusedRegistersByPopping(jit, preservedState);
state.emitExplicitExceptionHandler();
}
}
void AccessCase::emitIntrinsicGetter(AccessGenerationState& state)
{
CCallHelpers& jit = *state.jit;
JSValueRegs valueRegs = state.valueRegs;
GPRReg baseGPR = state.baseGPR;
GPRReg valueGPR = valueRegs.payloadGPR();
switch (intrinsic()) {
case TypedArrayLengthIntrinsic: {
jit.load32(MacroAssembler::Address(state.baseGPR, JSArrayBufferView::offsetOfLength()), valueGPR);
jit.boxInt32(valueGPR, valueRegs, CCallHelpers::DoNotHaveTagRegisters);
state.succeed();
return;
}
case TypedArrayByteLengthIntrinsic: {
TypedArrayType type = structure()->classInfo()->typedArrayStorageType;
jit.load32(MacroAssembler::Address(state.baseGPR, JSArrayBufferView::offsetOfLength()), valueGPR);
if (elementSize(type) > 1) {
// We can use a bitshift here since we TypedArrays cannot have byteLength that overflows an int32.
jit.lshift32(valueGPR, Imm32(logElementSize(type)), valueGPR);
}
jit.boxInt32(valueGPR, valueRegs, CCallHelpers::DoNotHaveTagRegisters);
state.succeed();
return;
}
case TypedArrayByteOffsetIntrinsic: {
GPRReg scratchGPR = state.scratchGPR;
CCallHelpers::Jump emptyByteOffset = jit.branch32(
MacroAssembler::NotEqual,
MacroAssembler::Address(baseGPR, JSArrayBufferView::offsetOfMode()),
TrustedImm32(WastefulTypedArray));
jit.loadPtr(MacroAssembler::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR);
jit.loadPtr(MacroAssembler::Address(baseGPR, JSArrayBufferView::offsetOfVector()), valueGPR);
jit.loadPtr(MacroAssembler::Address(scratchGPR, Butterfly::offsetOfArrayBuffer()), scratchGPR);
jit.loadPtr(MacroAssembler::Address(scratchGPR, ArrayBuffer::offsetOfData()), scratchGPR);
jit.subPtr(scratchGPR, valueGPR);
CCallHelpers::Jump done = jit.jump();
emptyByteOffset.link(&jit);
jit.move(TrustedImmPtr(0), valueGPR);
done.link(&jit);
jit.boxInt32(valueGPR, valueRegs, CCallHelpers::DoNotHaveTagRegisters);
state.succeed();
return;
}
default:
break;
}
RELEASE_ASSERT_NOT_REACHED();
}
