: m_jit(jit)

, m_oldFrame(data.numLocals + CallerFrameAndPC::sizeInRegisters, nullptr)

, m_newFrame(data.args.size() + CallFrame::headerSizeInRegisters, nullptr)

, m_alignedOldFrameSize(CallFrame::headerSizeInRegisters

+ roundArgumentCountToAlignFrame(jit.codeBlock()->numParameters()))

, m_alignedNewFrameSize(CallFrame::headerSizeInRegisters

+ roundArgumentCountToAlignFrame(data.args.size()))

, m_frameDelta(m_alignedNewFrameSize - m_alignedOldFrameSize)

, m_lockedRegisters(RegisterSet::allRegisters())

, m_numPassedArgs(data.numPassedArgs)

{

// We are allowed all the usual registers...

for (unsigned i = GPRInfo::numberOfRegisters; i--; )

m_lockedRegisters.clear(GPRInfo::toRegister(i));

for (unsigned i = FPRInfo::numberOfRegisters; i--; )

m_lockedRegisters.clear(FPRInfo::toRegister(i));

#if USE(JSVALUE64)

// ... as well as the runtime registers on 64-bit architectures.

// However do not use these registers on 32-bit architectures since

// saving and restoring callee-saved registers in CallFrameShuffler isn't supported

// on 32-bit architectures yet.

m_lockedRegisters.exclude(RegisterSet::vmCalleeSaveRegisters());

#endif

ASSERT(!data.callee.isInJSStack() || data.callee.virtualRegister().isLocal());

addNew(CallFrameSlot::callee, data.callee);

for (size_t i = 0; i < data.args.size(); ++i) {

ASSERT(!data.args[i].isInJSStack() || data.args[i].virtualRegister().isLocal());

addNew(virtualRegisterForArgumentIncludingThis(i), data.args[i]);

}

#if USE(JSVALUE64)

for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {

if (!data.registers[reg].isSet())

continue;

if (reg.isGPR())

addNew(JSValueRegs(reg.gpr()), data.registers[reg]);

else

addNew(reg.fpr(), data.registers[reg]);

}

m_numberTagRegister = data.numberTagRegister;

if (m_numberTagRegister != InvalidGPRReg)

lockGPR(m_numberTagRegister);

#endif

{

static const char* delimiter = " +-------------------------------+ ";

static const char* dangerDelimiter = " X-------------------------------X ";

static const char* dangerBoundsDelimiter = " XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ";

static const char* emptySpace = " ";

out.print(" ");

out.print(" Old frame ");

out.print(" New frame ");

out.print("\n");

int totalSize = m_alignedOldFrameSize + std::max(numLocals(), m_alignedNewFrameSize) + 3;

for (int i = 0; i < totalSize; ++i) {

VirtualRegister old { m_alignedOldFrameSize - i - 1 };

VirtualRegister newReg { old + m_frameDelta };

if (!isValidOld(old) && old != firstOld() - 1

&& !isValidNew(newReg) && newReg != firstNew() - 1)

continue;

out.print(" ");

if (dangerFrontier() >= firstNew()

&& (newReg == dangerFrontier() || newReg == firstNew() - 1))

out.print(dangerBoundsDelimiter);

else if (isValidOld(old))

out.print(isValidNew(newReg) && isDangerNew(newReg) ? dangerDelimiter : delimiter);

else if (old == firstOld() - 1)

out.print(delimiter);

else

out.print(emptySpace);

if (dangerFrontier() >= firstNew()

&& (newReg == dangerFrontier() || newReg == firstNew() - 1))

out.print(dangerBoundsDelimiter);

else if (isValidNew(newReg) || newReg == firstNew() - 1)

out.print(isDangerNew(newReg) ? dangerDelimiter : delimiter);

else

out.print(emptySpace);

out.print("\n");

if (old == firstOld())

out.print(" sp --> ");

else if (!old.offset())

out.print(" fp --> ");

else

out.print(" ");

if (isValidOld(old)) {

if (getOld(old)) {

auto str = toCString(old);

if (isValidNew(newReg) && isDangerNew(newReg))

out.printf(" X %18s X ", str.data());

else

out.printf(" | %18s | ", str.data());

} else if (isValidNew(newReg) && isDangerNew(newReg))

out.printf(" X%30s X ", "");

else

out.printf(" |%30s | ", "");

} else

out.print(emptySpace);

if (isValidNew(newReg)) {

const char d = isDangerNew(newReg) ? 'X' : '|';

auto str = toCString(newReg);

if (getNew(newReg)) {

if (getNew(newReg)->recovery().isConstant())

out.printf(" %c%8s <- constant %c ", d, str.data(), d);

else {

auto recoveryStr = toCString(getNew(newReg)->recovery());

out.printf(" %c%8s <- %18s %c ", d, str.data(),

recoveryStr.data(), d);

}

} else if (newReg == VirtualRegister { CallFrameSlot::argumentCountIncludingThis })

out.printf(" %c%8s <- %18zu %c ", d, str.data(), argCount(), d);

else

out.printf(" %c%30s %c ", d, "", d);

} else

out.print(emptySpace);

if (newReg == firstNew() - m_newFrameOffset && !isSlowPath())

out.print(" <-- new sp before jump (current ", m_newFrameBase, ") ");

if (newReg == firstNew())

out.print(" <-- new fp after prologue");

out.print("\n");

}

out.print(" ");

out.print(" Live registers ");

out.print(" Wanted registers ");

out.print("\n");

for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {

CachedRecovery* oldCachedRecovery { m_registers[reg] };

CachedRecovery* newCachedRecovery { m_newRegisters[reg] };

if (!oldCachedRecovery && !newCachedRecovery)

continue;

out.print(" ");

if (oldCachedRecovery) {

auto str = toCString(reg);

out.printf(" %8s ", str.data());

} else

out.print(emptySpace);

#if USE(JSVALUE32_64)

if (newCachedRecovery) {

JSValueRegs wantedJSValueRegs { newCachedRecovery->wantedJSValueRegs() };

if (reg.isFPR())

out.print(reg, " <- ", newCachedRecovery->recovery());

else {

if (reg.gpr() == wantedJSValueRegs.tagGPR())

out.print(reg.gpr(), " <- tag(", newCachedRecovery->recovery(), ")");

else

out.print(reg.gpr(), " <- payload(", newCachedRecovery->recovery(), ")");

}

}

#else

if (newCachedRecovery)

out.print(" ", reg, " <- ", newCachedRecovery->recovery());

#endif

out.print("\n");

}

out.print(" Locked registers: ");

bool firstLocked { true };

for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {

if (m_lockedRegisters.get(reg)) {

out.print(firstLocked ? "" : ", ", reg);

firstLocked = false;

}

}

out.print("\n");

if (isSlowPath())

out.print(" Using fp-relative addressing for slow path call\n");

else

out.print(" Using sp-relative addressing for jump (using ", m_newFrameBase, " as new sp)\n");

if (m_oldFrameOffset)

out.print(" Old frame offset is ", m_oldFrameOffset, "\n");

if (m_newFrameOffset)

out.print(" New frame offset is ", m_newFrameOffset, "\n");

#if USE(JSVALUE64)

if (m_numberTagRegister != InvalidGPRReg)

out.print(" NumberTag is currently in ", m_numberTagRegister, "\n");

#endif

{

ASSERT(!isSlowPath());

ASSERT(cachedRecovery.recovery().isInRegisters());

VirtualRegister spillSlot { 0 };

for (VirtualRegister slot = firstOld(); slot <= lastOld(); slot += 1) {

if (slot >= newAsOld(firstNew()))

break;

if (getOld(slot))

continue;

spillSlot = slot;

break;

}

// We must have enough slots to be able to fit the whole callee's

// frame for the slow path - unless we are in the FTL. In that

// case, we are allowed to extend the frame *once*, since we are

// guaranteed to have enough available space for that.

if (spillSlot >= newAsOld(firstNew()) || !spillSlot.isLocal()) {

RELEASE_ASSERT(!m_didExtendFrame);

extendFrameIfNeeded();

spill(cachedRecovery);

return;

}

if (verbose)

dataLog(" * Spilling ", cachedRecovery.recovery(), " into ", spillSlot, "\n");

auto format = emitStore(cachedRecovery, addressForOld(spillSlot));

ASSERT(format != DataFormatNone);

updateRecovery(cachedRecovery, ValueRecovery::displacedInJSStack(spillSlot, format));

{

if (!ASSERT_ENABLED)

return;

GPRReg scratchGPR { getFreeGPR() };

if (scratchGPR != InvalidGPRReg) {

if (verbose)

dataLog(" Using ", scratchGPR, " for the fp-sp delta check\n");

m_jit.move(MacroAssembler::stackPointerRegister, scratchGPR);

m_jit.subPtr(GPRInfo::callFrameRegister, scratchGPR);

MacroAssembler::Jump ok = m_jit.branch32(

MacroAssembler::Equal, scratchGPR,

MacroAssembler::TrustedImm32(-numLocals() * sizeof(Register)));

m_jit.abortWithReason(JITUnexpectedCallFrameSize);

ok.link(&m_jit);

} else if (verbose)

dataLog(" Skipping the fp-sp delta check since there is too much pressure");

{

ASSERT(!m_didExtendFrame);

VirtualRegister firstRead { firstOld() };

for (; firstRead <= virtualRegisterForLocal(0); firstRead += 1) {

if (getOld(firstRead))

break;

}

size_t availableSize = static_cast<size_t>(firstRead.offset() - firstOld().offset());

size_t wantedSize = m_newFrame.size() + m_newFrameOffset;

if (availableSize < wantedSize) {

size_t delta = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), wantedSize - availableSize);

m_oldFrame.grow(m_oldFrame.size() + delta);

for (size_t i = 0; i < delta; ++i)

m_oldFrame[m_oldFrame.size() - i - 1] = nullptr;

m_jit.subPtr(MacroAssembler::TrustedImm32(delta * sizeof(Register)), MacroAssembler::stackPointerRegister);

if (isSlowPath())

m_frameDelta = numLocals() + CallerFrameAndPC::sizeInRegisters;

else

m_oldFrameOffset = numLocals();

if (verbose)

dataLogF(" Not enough space - extending the old frame %zu slot\n", delta);

}

m_didExtendFrame = true;

{

ASSERT(isUndecided());

emitDeltaCheck();

m_frameDelta = numLocals() + CallerFrameAndPC::sizeInRegisters;

m_newFrameBase = MacroAssembler::stackPointerRegister;

m_newFrameOffset = -CallerFrameAndPC::sizeInRegisters;

if (verbose)

dataLog("\n\nPreparing frame for slow path call:\n");

// When coming from the FTL, we need to extend the frame. In other

// cases, we may end up extending the frame if we previously

// spilled things (e.g. in polymorphic cache).

extendFrameIfNeeded();

if (verbose)

dataLog(*this);

prepareAny();

if (verbose)

dataLog("Ready for slow path call!\n");

{

ASSERT(isUndecided());

emitDeltaCheck();

// We'll use sp-based indexing so that we can load the

// caller's frame pointer into the fpr immediately

m_oldFrameBase = MacroAssembler::stackPointerRegister;

m_oldFrameOffset = numLocals();

m_newFrameBase = acquireGPR();

#if CPU(ARM_THUMB2) || CPU(MIPS)

// We load the frame pointer and link register

// manually. We could ask the algorithm to load them for us,

// and it would allow us to use the link register as an extra

// temporary - but it'd mean that the frame pointer can also

// be used as an extra temporary, so we keep the link register

// locked instead.

// sp will point to head1 since the callee's prologue pushes

// the call frame and link register.

m_newFrameOffset = -1;

#elif CPU(ARM64)

// We load the frame pointer and link register manually. We

// could ask the algorithm to load the link register for us

// (which would allow for its use as an extra temporary), but

// since its not in GPRInfo, we can't do it.

// sp will point to head2 since the callee's prologue pushes the

// call frame and link register

m_newFrameOffset = -2;

#elif CPU(X86_64)

// We load the frame pointer manually, but we ask the

// algorithm to move the return PC for us (it'd probably

// require a write in the danger zone)

addNew(VirtualRegister { 1 },

ValueRecovery::displacedInJSStack(VirtualRegister(1), DataFormatJS));

// sp will point to head1 since the callee's prologue pushes

// the call frame register

m_newFrameOffset = -1;

#else

UNREACHABLE_FOR_PLATFORM();

#endif

if (verbose)

dataLog(" Emitting code for computing the new frame base\n");

// We compute the new frame base by first computing the top of the

// old frame (taking into account an argument count higher than

// the number of parameters), then substracting to it the aligned

// new frame size (adjusted).

m_jit.load32(MacroAssembler::Address(GPRInfo::callFrameRegister, CallFrameSlot::argumentCountIncludingThis * static_cast<int>(sizeof(Register)) + PayloadOffset), m_newFrameBase);

MacroAssembler::Jump argumentCountOK =

m_jit.branch32(MacroAssembler::BelowOrEqual, m_newFrameBase,

MacroAssembler::TrustedImm32(m_jit.codeBlock()->numParameters()));

m_jit.add32(MacroAssembler::TrustedImm32(stackAlignmentRegisters() - 1 + CallFrame::headerSizeInRegisters), m_newFrameBase);

m_jit.and32(MacroAssembler::TrustedImm32(-stackAlignmentRegisters()), m_newFrameBase);

m_jit.mul32(MacroAssembler::TrustedImm32(sizeof(Register)), m_newFrameBase, m_newFrameBase);

MacroAssembler::Jump done = m_jit.jump();

argumentCountOK.link(&m_jit);

m_jit.move(

MacroAssembler::TrustedImm32(m_alignedOldFrameSize * sizeof(Register)),

m_newFrameBase);

done.link(&m_jit);

m_jit.addPtr(GPRInfo::callFrameRegister, m_newFrameBase);

m_jit.subPtr(

MacroAssembler::TrustedImm32(

(m_alignedNewFrameSize + m_newFrameOffset) * sizeof(Register)),

m_newFrameBase);

// We load the link register manually for architectures that have one

#if CPU(ARM_THUMB2) || CPU(ARM64)

m_jit.loadPtr(MacroAssembler::Address(MacroAssembler::framePointerRegister, CallFrame::returnPCOffset()),

MacroAssembler::linkRegister);

#if CPU(ARM64E)

m_jit.addPtr(MacroAssembler::TrustedImm32(sizeof(CallerFrameAndPC)), MacroAssembler::framePointerRegister);

m_jit.untagPtr(MacroAssembler::framePointerRegister, MacroAssembler::linkRegister);

m_jit.subPtr(MacroAssembler::TrustedImm32(sizeof(CallerFrameAndPC)), MacroAssembler::framePointerRegister);

#endif

#elif CPU(MIPS)

m_jit.loadPtr(MacroAssembler::Address(MacroAssembler::framePointerRegister, sizeof(void*)),

MacroAssembler::returnAddressRegister);

#endif

// We want the frame pointer to always point to a valid frame, and

// we are going to trash the current one. Let's make it point to

// our caller's frame, since that's what we want to end up with.

m_jit.loadPtr(MacroAssembler::Address(MacroAssembler::framePointerRegister),

MacroAssembler::framePointerRegister);

if (verbose)

dataLog("Preparing frame for tail call:\n", *this);

prepareAny();

if (verbose)

dataLog("Ready for tail call!\n");

{

ASSERT(m_newFrameBase != InvalidGPRReg);

// If the value is already set up correctly, we don't have

// anything to do.

if (isSlowPath() && cachedRecovery.recovery().isInJSStack()

&& cachedRecovery.targets().size() == 1

&& newAsOld(cachedRecovery.targets()[0]) == cachedRecovery.recovery().virtualRegister()) {

cachedRecovery.clearTargets();

if (!cachedRecovery.wantedJSValueRegs() && cachedRecovery.wantedFPR() == InvalidFPRReg)

clearCachedRecovery(cachedRecovery.recovery());

return true;

}

if (!canLoadAndBox(cachedRecovery))

return false;

emitLoad(cachedRecovery);

emitBox(cachedRecovery);

ASSERT(cachedRecovery.recovery().isInRegisters()

|| cachedRecovery.recovery().isConstant());

if (verbose)

dataLog(" * Storing ", cachedRecovery.recovery());

for (size_t i = 0; i < cachedRecovery.targets().size(); ++i) {

VirtualRegister target { cachedRecovery.targets()[i] };

ASSERT(!isDangerNew(target));

if (verbose)

dataLog(!i ? " into " : ", and ", "NEW ", target);

emitStore(cachedRecovery, addressForNew(target));

setNew(target, nullptr);

}

if (verbose)

dataLog("\n");

cachedRecovery.clearTargets();

if (!cachedRecovery.wantedJSValueRegs() && cachedRecovery.wantedFPR() == InvalidFPRReg)

clearCachedRecovery(cachedRecovery.recovery());

return true;

{

VirtualRegister firstSafe;

VirtualRegister end { lastNew() + 1 };

Vector<VirtualRegister> failures;

// For all cachedRecoveries that writes to the safe zone, if it

// doesn't also write to the danger zone, we try to perform

// the writes. This may free up danger slots, so we iterate

// again until it doesn't happen anymore.

//

// Note that even though we have a while block, we look at

// each slot of the new call frame at most once since in each

// iteration beyond the first, we only load up the portion of

// the new call frame that was dangerous and became safe due

// to the previous iteration.

do {

firstSafe = dangerFrontier() + 1;

if (verbose)

dataLog(" Trying safe writes (between NEW ", firstSafe, " and NEW ", end - 1, ")\n");

bool didProgress = false;

for (VirtualRegister reg = firstSafe; reg < end; reg += 1) {

CachedRecovery* cachedRecovery = getNew(reg);

if (!cachedRecovery) {

if (verbose)

dataLog(" + ", reg, " is OK.\n");

continue;

}

if (!hasOnlySafeWrites(*cachedRecovery)) {

if (verbose) {

dataLog(" - ", cachedRecovery->recovery(), " writes to NEW ", reg,

" but also has dangerous writes.\n");

}

continue;

}

if (cachedRecovery->wantedJSValueRegs()) {

if (verbose) {

dataLog(" - ", cachedRecovery->recovery(), " writes to NEW ", reg,

" but is also needed in registers.\n");

}

continue;

}

if (cachedRecovery->wantedFPR() != InvalidFPRReg) {

if (verbose) {

dataLog(" - ", cachedRecovery->recovery(), " writes to NEW ", reg,

" but is also needed in an FPR.\n");

}

continue;

}

if (!tryWrites(*cachedRecovery)) {

if (verbose)

dataLog(" - Unable to write to NEW ", reg, " from ", cachedRecovery->recovery(), "\n");

failures.append(reg);

}

didProgress = true;

}

end = firstSafe;

// If we have cachedRecoveries that failed to write, it is

// because they are on the stack and we didn't have enough

// registers available at the time to load them into. If

// we have a free register, we should try again because it

// could free up some danger slots.

if (didProgress && hasFreeRegister()) {

Vector<VirtualRegister> stillFailing;

for (VirtualRegister failed : failures) {

CachedRecovery* cachedRecovery = getNew(failed);

// It could have been handled later if it had

// several targets

if (!cachedRecovery)

continue;

ASSERT(hasOnlySafeWrites(*cachedRecovery)

&& !cachedRecovery->wantedJSValueRegs()

&& cachedRecovery->wantedFPR() == InvalidFPRReg);

if (!tryWrites(*cachedRecovery))

stillFailing.append(failed);

}

failures = WTFMove(stillFailing);

}

if (verbose && firstSafe != dangerFrontier() + 1)

dataLog(" We freed up danger slots!\n");

} while (firstSafe != dangerFrontier() + 1);

return failures.isEmpty();

{

ASSERT(!isUndecided());

updateDangerFrontier();

// First, we try to store any value that goes above the danger

// frontier. This will never use more registers since we are only

// loading+storing if we ensure that any register used for the load

// will be freed up after the stores (i.e., all stores are above

// the danger frontier, and there is no wanted register).

performSafeWrites();

// At this point, we couldn't have more available registers than

// we have withouth spilling: all values currently in registers

// either require a write to the danger zone, or have a wanted

// register, which means that in any case they will have to go

// through registers again.

// We now slowly free up the danger zone by first loading the old

// value on the danger frontier, spilling as many registers as

// needed to do so and ensuring that the corresponding slot in the

// new frame is now ready to be written. Then, we store the old

// value to its target location if possible (we could have failed

// to load it previously due to high pressure). Finally, we write

// to any of the newly safe slots that we can, which could free up

// registers (hence why we do it eagerly).

for (VirtualRegister reg = dangerFrontier(); reg >= firstNew(); reg -= 1) {

if (reg == dangerFrontier()) {

if (verbose)

dataLog(" Next slot (NEW ", reg, ") is the danger frontier\n");

CachedRecovery* cachedRecovery { getOld(newAsOld(dangerFrontier())) };

ASSERT(cachedRecovery);

ensureLoad(*cachedRecovery);

emitLoad(*cachedRecovery);

ensureBox(*cachedRecovery);

emitBox(*cachedRecovery);

if (hasOnlySafeWrites(*cachedRecovery))

tryWrites(*cachedRecovery);

} else if (verbose)

dataLog(" Next slot is NEW ", reg, "\n");

ASSERT(!isDangerNew(reg));

CachedRecovery* cachedRecovery = getNew(reg);

// This could be one of the header slots we don't care about.

if (!cachedRecovery) {

if (verbose)

dataLog(" + ", reg, " is OK\n");

continue;

}

if (canLoadAndBox(*cachedRecovery) && hasOnlySafeWrites(*cachedRecovery)

&& !cachedRecovery->wantedJSValueRegs()

&& cachedRecovery->wantedFPR() == InvalidFPRReg) {

emitLoad(*cachedRecovery);

emitBox(*cachedRecovery);

bool writesOK = tryWrites(*cachedRecovery);

ASSERT_UNUSED(writesOK, writesOK);

} else if (verbose)

dataLog(" - ", cachedRecovery->recovery(), " can't be handled just yet.\n");

}

ASSERT(dangerFrontier() < firstNew());

// Now, the danger zone is empty, but we still have a couple of

// things to do:

//

// 1) There could be remaining safe writes that failed earlier due

// to high register pressure and had nothing to do with the

// danger zone whatsoever.

//

// 2) Some wanted registers could have to be loaded (this could

// happen either when making a call to a new function with a

// lower number of arguments - since above here, we only load

// wanted registers when they are at the danger frontier -, or

// if a wanted register got spilled).

//

// 3) Some wanted registers could have been loaded in the wrong

// registers

//

// 4) We have to take care of some bookkeeping - namely, storing

// the argument count and updating the stack pointer.

// At this point, we must have enough registers available for

// handling 1). None of the loads can fail because we have been

// eagerly freeing up registers in all the previous phases - so

// the only values that are in registers at this point must have

// wanted registers.

if (verbose)

dataLog(" Danger zone is clear, performing remaining writes.\n");

for (VirtualRegister reg = firstNew(); reg <= lastNew(); reg += 1) {

CachedRecovery* cachedRecovery { getNew(reg) };

if (!cachedRecovery)

continue;

emitLoad(*cachedRecovery);

emitBox(*cachedRecovery);

bool writesOK = tryWrites(*cachedRecovery);

ASSERT_UNUSED(writesOK, writesOK);

}

#if USE(JSVALUE64)

if (m_numberTagRegister != InvalidGPRReg && m_newRegisters[m_numberTagRegister])

releaseGPR(m_numberTagRegister);

#endif

// Handle 2) by loading all registers. We don't have to do any

// writes, since they have been taken care of above.

if (verbose)

dataLog(" Loading wanted registers into registers\n");

for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {

CachedRecovery* cachedRecovery { m_newRegisters[reg] };

if (!cachedRecovery)

continue;

emitLoad(*cachedRecovery);

emitBox(*cachedRecovery);

ASSERT(cachedRecovery->targets().isEmpty());

}

#if USE(JSVALUE64)

if (m_numberTagRegister != InvalidGPRReg)

releaseGPR(m_numberTagRegister);

#endif

// At this point, we have read everything we cared about from the

// stack, and written everything we had to to the stack.

if (verbose)

dataLog(" Callee frame is fully set up\n");

if (ASSERT_ENABLED) {

for (VirtualRegister reg = firstNew(); reg <= lastNew(); reg += 1)

ASSERT_UNUSED(reg, !getNew(reg));

for (CachedRecovery* cachedRecovery : m_cachedRecoveries) {

ASSERT_UNUSED(cachedRecovery, cachedRecovery->targets().isEmpty());

ASSERT(!cachedRecovery->recovery().isInJSStack());

}

}

// We need to handle 4) first because it implies releasing

// m_newFrameBase, which could be a wanted register.

if (verbose)

dataLog(" * Storing the argument count into ", VirtualRegister { CallFrameSlot::argumentCountIncludingThis }, "\n");

m_jit.store32(MacroAssembler::TrustedImm32(0),

addressForNew(VirtualRegister { CallFrameSlot::argumentCountIncludingThis }).withOffset(TagOffset));

RELEASE_ASSERT(m_numPassedArgs != UINT_MAX);

m_jit.store32(MacroAssembler::TrustedImm32(m_numPassedArgs),

addressForNew(VirtualRegister { CallFrameSlot::argumentCountIncludingThis }).withOffset(PayloadOffset));

if (!isSlowPath()) {

ASSERT(m_newFrameBase != MacroAssembler::stackPointerRegister);

if (verbose)

dataLog(" Releasing the new frame base pointer\n");

m_jit.move(m_newFrameBase, MacroAssembler::stackPointerRegister);

releaseGPR(m_newFrameBase);

}

// Finally we handle 3)

if (verbose)

dataLog(" Ensuring wanted registers are in the right register\n");

for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {

CachedRecovery* cachedRecovery { m_newRegisters[reg] };

if (!cachedRecovery)

continue;

emitDisplace(*cachedRecovery);

}