MacroAssemblerCodeRef throwExceptionFromCallSlowPathGenerator(JSGlobalData* globalData)
{
CCallHelpers jit(globalData);
// We will jump to here if the JIT code thinks it's making a call, but the
// linking helper (C++ code) decided to throw an exception instead. We will
// have saved the callReturnIndex in the first arguments of JITStackFrame.
// Note that the return address will be on the stack at this point, so we
// need to remove it and drop it on the floor, since we don't care about it.
// Finally note that the call frame register points at the callee frame, so
// we need to pop it.
jit.preserveReturnAddressAfterCall(GPRInfo::nonPreservedNonReturnGPR);
jit.loadPtr(
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * RegisterFile::CallerFrame),
GPRInfo::callFrameRegister);
jit.peek(GPRInfo::nonPreservedNonReturnGPR, JITSTACKFRAME_ARGS_INDEX);
jit.setupArgumentsWithExecState(GPRInfo::nonPreservedNonReturnGPR);
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(lookupExceptionHandler)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::returnValueGPR2);
jit.jump(GPRInfo::returnValueGPR2);
LinkBuffer patchBuffer(*globalData, &jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(patchBuffer, ("DFG throw exception from call slow path thunk"));
}
static void slowPathFor(
CCallHelpers& jit, VM* vm, Sprt_JITOperation_ECli slowPathFunction)
{
jit.emitFunctionPrologue();
jit.storePtr(GPRInfo::callFrameRegister, &vm->topCallFrame);
#if OS(WINDOWS) && CPU(X86_64)
// Windows X86_64 needs some space pointed to by arg0 for return types larger than 64 bits.
// Other argument values are shift by 1. Use space on the stack for our two return values.
// Moving the stack down maxFrameExtentForSlowPathCall bytes gives us room for our 3 arguments
// and space for the 16 byte return area.
jit.addPtr(CCallHelpers::TrustedImm32(-maxFrameExtentForSlowPathCall), CCallHelpers::stackPointerRegister);
jit.move(GPRInfo::regT2, GPRInfo::argumentGPR2);
jit.addPtr(CCallHelpers::TrustedImm32(32), CCallHelpers::stackPointerRegister, GPRInfo::argumentGPR0);
jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(slowPathFunction)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
jit.loadPtr(CCallHelpers::Address(GPRInfo::returnValueGPR, 8), GPRInfo::returnValueGPR2);
jit.loadPtr(CCallHelpers::Address(GPRInfo::returnValueGPR), GPRInfo::returnValueGPR);
jit.addPtr(CCallHelpers::TrustedImm32(maxFrameExtentForSlowPathCall), CCallHelpers::stackPointerRegister);
#else
if (maxFrameExtentForSlowPathCall)
jit.addPtr(CCallHelpers::TrustedImm32(-maxFrameExtentForSlowPathCall), CCallHelpers::stackPointerRegister);
jit.setupArgumentsWithExecState(GPRInfo::regT2);
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(slowPathFunction)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
if (maxFrameExtentForSlowPathCall)
jit.addPtr(CCallHelpers::TrustedImm32(maxFrameExtentForSlowPathCall), CCallHelpers::stackPointerRegister);
#endif
// This slow call will return the address of one of the following:
// 1) Exception throwing thunk.
// 2) Host call return value returner thingy.
// 3) The function to call.
// The second return value GPR will hold a non-zero value for tail calls.
emitPointerValidation(jit, GPRInfo::returnValueGPR);
jit.emitFunctionEpilogue();
RELEASE_ASSERT(reinterpret_cast<void*>(KeepTheFrame) == reinterpret_cast<void*>(0));
CCallHelpers::Jump doNotTrash = jit.branchTestPtr(CCallHelpers::Zero, GPRInfo::returnValueGPR2);
jit.preserveReturnAddressAfterCall(GPRInfo::nonPreservedNonReturnGPR);
jit.prepareForTailCallSlow(GPRInfo::returnValueGPR);
doNotTrash.link(&jit);
jit.jump(GPRInfo::returnValueGPR);
}
static void slowPathFor(
CCallHelpers& jit, JSGlobalData* globalData, P_DFGOperation_E slowPathFunction)
{
jit.preserveReturnAddressAfterCall(GPRInfo::nonArgGPR2);
emitPointerValidation(jit, GPRInfo::nonArgGPR2);
jit.storePtr(
GPRInfo::nonArgGPR2,
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * JSStack::ReturnPC));
jit.storePtr(GPRInfo::callFrameRegister, &globalData->topCallFrame);
#if USE(JSVALUE64)
jit.poke64(GPRInfo::nonPreservedNonReturnGPR, JITSTACKFRAME_ARGS_INDEX);
#else
jit.poke(GPRInfo::nonPreservedNonReturnGPR, JITSTACKFRAME_ARGS_INDEX);
#endif
jit.setupArgumentsExecState();
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(slowPathFunction)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
// This slow call will return the address of one of the following:
// 1) Exception throwing thunk.
// 2) Host call return value returner thingy.
// 3) The function to call.
jit.loadPtr(
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * JSStack::ReturnPC),
GPRInfo::nonPreservedNonReturnGPR);
jit.storePtr(
CCallHelpers::TrustedImmPtr(0),
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * JSStack::ReturnPC));
emitPointerValidation(jit, GPRInfo::nonPreservedNonReturnGPR);
jit.restoreReturnAddressBeforeReturn(GPRInfo::nonPreservedNonReturnGPR);
emitPointerValidation(jit, GPRInfo::returnValueGPR);
jit.jump(GPRInfo::returnValueGPR);
}
static void slowPathFor(
CCallHelpers& jit, VM* vm, P_JITOperation_E slowPathFunction)
{
jit.emitFunctionPrologue();
jit.storePtr(GPRInfo::callFrameRegister, &vm->topCallFrame);
if (maxFrameExtentForSlowPathCall)
jit.addPtr(CCallHelpers::TrustedImm32(-maxFrameExtentForSlowPathCall), CCallHelpers::stackPointerRegister);
jit.setupArgumentsExecState();
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(slowPathFunction)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
if (maxFrameExtentForSlowPathCall)
jit.addPtr(CCallHelpers::TrustedImm32(maxFrameExtentForSlowPathCall), CCallHelpers::stackPointerRegister);
// This slow call will return the address of one of the following:
// 1) Exception throwing thunk.
// 2) Host call return value returner thingy.
// 3) The function to call.
emitPointerValidation(jit, GPRInfo::returnValueGPR);
jit.emitFunctionEpilogue();
jit.jump(GPRInfo::returnValueGPR);
}
static void slowPathFor(
CCallHelpers& jit, VM* vm, P_JITOperation_E slowPathFunction)
{
jit.preserveReturnAddressAfterCall(GPRInfo::nonArgGPR2);
emitPointerValidation(jit, GPRInfo::nonArgGPR2);
jit.emitPutReturnPCToCallFrameHeader(GPRInfo::nonArgGPR2);
jit.storePtr(GPRInfo::callFrameRegister, &vm->topCallFrame);
jit.setupArgumentsExecState();
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(slowPathFunction)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
// This slow call will return the address of one of the following:
// 1) Exception throwing thunk.
// 2) Host call return value returner thingy.
// 3) The function to call.
jit.emitGetReturnPCFromCallFrameHeaderPtr(GPRInfo::nonPreservedNonReturnGPR);
jit.emitPutReturnPCToCallFrameHeader(CCallHelpers::TrustedImmPtr(0));
emitPointerValidation(jit, GPRInfo::nonPreservedNonReturnGPR);
jit.restoreReturnAddressBeforeReturn(GPRInfo::nonPreservedNonReturnGPR);
emitPointerValidation(jit, GPRInfo::returnValueGPR);
jit.jump(GPRInfo::returnValueGPR);
}
// We will jump here if the JIT code tries to make a call, but the
// linking helper (C++ code) decides to throw an exception instead.
MacroAssemblerCodeRef throwExceptionFromCallSlowPathGenerator(VM* vm)
{
CCallHelpers jit(vm);
// The call pushed a return address, so we need to pop it back off to re-align the stack,
// even though we won't use it.
jit.preserveReturnAddressAfterCall(GPRInfo::nonPreservedNonReturnGPR);
jit.setupArguments(CCallHelpers::TrustedImmPtr(vm), GPRInfo::callFrameRegister);
jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(lookupExceptionHandler)), GPRInfo::nonArgGPR0);
emitPointerValidation(jit, GPRInfo::nonArgGPR0);
jit.call(GPRInfo::nonArgGPR0);
jit.jumpToExceptionHandler();
LinkBuffer patchBuffer(*vm, &jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(patchBuffer, ("Throw exception from call slow path thunk"));
}
static MacroAssemblerCodeRef virtualForThunkGenerator(
VM* vm, CodeSpecializationKind kind, RegisterPreservationMode registers)
{
// The callee is in regT0 (for JSVALUE32_64, the tag is in regT1).
// The return address is on the stack, or in the link register. We will hence
// jump to the callee, or save the return address to the call frame while we
// make a C++ function call to the appropriate JIT operation.
CCallHelpers jit(vm);
CCallHelpers::JumpList slowCase;
// FIXME: we should have a story for eliminating these checks. In many cases,
// the DFG knows that the value is definitely a cell, or definitely a function.
#if USE(JSVALUE64)
jit.move(CCallHelpers::TrustedImm64(TagMask), GPRInfo::regT2);
slowCase.append(
jit.branchTest64(
CCallHelpers::NonZero, GPRInfo::regT0, GPRInfo::regT2));
#else
slowCase.append(
jit.branch32(
CCallHelpers::NotEqual, GPRInfo::regT1,
CCallHelpers::TrustedImm32(JSValue::CellTag)));
#endif
AssemblyHelpers::emitLoadStructure(jit, GPRInfo::regT0, GPRInfo::regT2, GPRInfo::regT1);
slowCase.append(
jit.branchPtr(
CCallHelpers::NotEqual,
CCallHelpers::Address(GPRInfo::regT2, Structure::classInfoOffset()),
CCallHelpers::TrustedImmPtr(JSFunction::info())));
// Now we know we have a JSFunction.
jit.loadPtr(
CCallHelpers::Address(GPRInfo::regT0, JSFunction::offsetOfExecutable()),
GPRInfo::regT2);
jit.loadPtr(
CCallHelpers::Address(
GPRInfo::regT2, ExecutableBase::offsetOfJITCodeWithArityCheckFor(kind, registers)),
GPRInfo::regT2);
slowCase.append(jit.branchTestPtr(CCallHelpers::Zero, GPRInfo::regT2));
// Now we know that we have a CodeBlock, and we're committed to making a fast
// call.
jit.loadPtr(
CCallHelpers::Address(GPRInfo::regT0, JSFunction::offsetOfScopeChain()),
GPRInfo::regT1);
#if USE(JSVALUE64)
jit.emitPutToCallFrameHeaderBeforePrologue(GPRInfo::regT1, JSStack::ScopeChain);
#else
jit.emitPutPayloadToCallFrameHeaderBeforePrologue(GPRInfo::regT1, JSStack::ScopeChain);
jit.emitPutTagToCallFrameHeaderBeforePrologue(CCallHelpers::TrustedImm32(JSValue::CellTag),
JSStack::ScopeChain);
#endif
// Make a tail call. This will return back to JIT code.
emitPointerValidation(jit, GPRInfo::regT2);
jit.jump(GPRInfo::regT2);
slowCase.link(&jit);
// Here we don't know anything, so revert to the full slow path.
slowPathFor(jit, vm, operationVirtualFor(kind, registers));
LinkBuffer patchBuffer(*vm, &jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(
patchBuffer,
("Virtual %s%s slow path thunk", kind == CodeForCall ? "call" : "construct", registers == MustPreserveRegisters ? " that preserves registers" : ""));
}
static MacroAssemblerCodeRef virtualForThunkGenerator(
JSGlobalData* globalData, CodeSpecializationKind kind)
{
// The return address is on the stack, or in the link register. We will hence
// jump to the callee, or save the return address to the call frame while we
// make a C++ function call to the appropriate DFG operation.
CCallHelpers jit(globalData);
CCallHelpers::JumpList slowCase;
// FIXME: we should have a story for eliminating these checks. In many cases,
// the DFG knows that the value is definitely a cell, or definitely a function.
#if USE(JSVALUE64)
slowCase.append(
jit.branchTestPtr(
CCallHelpers::NonZero, GPRInfo::nonArgGPR0, GPRInfo::tagMaskRegister));
#else
slowCase.append(
jit.branch32(
CCallHelpers::NotEqual, GPRInfo::nonArgGPR1,
CCallHelpers::TrustedImm32(JSValue::CellTag)));
#endif
jit.loadPtr(CCallHelpers::Address(GPRInfo::nonArgGPR0, JSCell::structureOffset()), GPRInfo::nonArgGPR2);
slowCase.append(
jit.branchPtr(
CCallHelpers::NotEqual,
CCallHelpers::Address(GPRInfo::nonArgGPR2, Structure::classInfoOffset()),
CCallHelpers::TrustedImmPtr(&JSFunction::s_info)));
// Now we know we have a JSFunction.
jit.loadPtr(
CCallHelpers::Address(GPRInfo::nonArgGPR0, JSFunction::offsetOfExecutable()),
GPRInfo::nonArgGPR2);
slowCase.append(
jit.branch32(
CCallHelpers::LessThan,
CCallHelpers::Address(
GPRInfo::nonArgGPR2, ExecutableBase::offsetOfNumParametersFor(kind)),
CCallHelpers::TrustedImm32(0)));
// Now we know that we have a CodeBlock, and we're committed to making a fast
// call.
jit.loadPtr(
CCallHelpers::Address(GPRInfo::nonArgGPR0, JSFunction::offsetOfScopeChain()),
GPRInfo::nonArgGPR1);
#if USE(JSVALUE64)
jit.storePtr(
GPRInfo::nonArgGPR1,
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * RegisterFile::ScopeChain));
#else
jit.storePtr(
GPRInfo::nonArgGPR1,
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * RegisterFile::ScopeChain +
OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload)));
jit.store32(
CCallHelpers::TrustedImm32(JSValue::CellTag),
CCallHelpers::Address(
GPRInfo::callFrameRegister,
static_cast<ptrdiff_t>(sizeof(Register)) * RegisterFile::ScopeChain +
OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.tag)));
#endif
jit.loadPtr(
CCallHelpers::Address(GPRInfo::nonArgGPR2, ExecutableBase::offsetOfJITCodeWithArityCheckFor(kind)),
GPRInfo::regT0);
// Make a tail call. This will return back to DFG code.
emitPointerValidation(jit, GPRInfo::regT0);
jit.jump(GPRInfo::regT0);
slowCase.link(&jit);
// Here we don't know anything, so revert to the full slow path.
slowPathFor(jit, globalData, kind == CodeForCall ? operationVirtualCall : operationVirtualConstruct);
LinkBuffer patchBuffer(*globalData, &jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(
patchBuffer,
("DFG virtual %s slow path thunk", kind == CodeForCall ? "call" : "construct"));
}
// FIXME: We should distinguish between a megamorphic virtual call vs. a slow
// path virtual call so that we can enable fast tail calls for megamorphic
// virtual calls by using the shuffler.
// https://bugs.webkit.org/show_bug.cgi?id=148831
MacroAssemblerCodeRef virtualThunkFor(VM* vm, CallLinkInfo& callLinkInfo)
{
// The callee is in regT0 (for JSVALUE32_64, the tag is in regT1).
// The return address is on the stack, or in the link register. We will hence
// jump to the callee, or save the return address to the call frame while we
// make a C++ function call to the appropriate JIT operation.
CCallHelpers jit(vm);
CCallHelpers::JumpList slowCase;
// This is a slow path execution, and regT2 contains the CallLinkInfo. Count the
// slow path execution for the profiler.
jit.add32(
CCallHelpers::TrustedImm32(1),
CCallHelpers::Address(GPRInfo::regT2, CallLinkInfo::offsetOfSlowPathCount()));
// FIXME: we should have a story for eliminating these checks. In many cases,
// the DFG knows that the value is definitely a cell, or definitely a function.
#if USE(JSVALUE64)
jit.move(CCallHelpers::TrustedImm64(TagMask), GPRInfo::regT4);
slowCase.append(
jit.branchTest64(
CCallHelpers::NonZero, GPRInfo::regT0, GPRInfo::regT4));
#else
slowCase.append(
jit.branch32(
CCallHelpers::NotEqual, GPRInfo::regT1,
CCallHelpers::TrustedImm32(JSValue::CellTag)));
#endif
AssemblyHelpers::emitLoadStructure(jit, GPRInfo::regT0, GPRInfo::regT4, GPRInfo::regT1);
slowCase.append(
jit.branchPtr(
CCallHelpers::NotEqual,
CCallHelpers::Address(GPRInfo::regT4, Structure::classInfoOffset()),
CCallHelpers::TrustedImmPtr(JSFunction::info())));
// Now we know we have a JSFunction.
jit.loadPtr(
CCallHelpers::Address(GPRInfo::regT0, JSFunction::offsetOfExecutable()),
GPRInfo::regT4);
jit.loadPtr(
CCallHelpers::Address(
GPRInfo::regT4, ExecutableBase::offsetOfJITCodeWithArityCheckFor(
callLinkInfo.specializationKind())),
GPRInfo::regT4);
slowCase.append(jit.branchTestPtr(CCallHelpers::Zero, GPRInfo::regT4));
// Now we know that we have a CodeBlock, and we're committed to making a fast
// call.
// Make a tail call. This will return back to JIT code.
emitPointerValidation(jit, GPRInfo::regT4);
if (callLinkInfo.isTailCall()) {
jit.preserveReturnAddressAfterCall(GPRInfo::regT0);
jit.prepareForTailCallSlow(GPRInfo::regT4);
}
jit.jump(GPRInfo::regT4);
slowCase.link(&jit);
// Here we don't know anything, so revert to the full slow path.
slowPathFor(jit, vm, operationVirtualCall);
LinkBuffer patchBuffer(*vm, jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(
patchBuffer,
("Virtual %s slow path thunk",
callLinkInfo.callMode() == CallMode::Regular ? "call" : callLinkInfo.callMode() == CallMode::Tail ? "tail call" : "construct"));
}
