blob: be5b72c9c660a875bf768e4567b1a9fdd60e8140 [file] [log] [blame]
/*
* Copyright (C) 2014-2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "ScratchRegisterAllocator.h"
#if ENABLE(JIT)
#include "MaxFrameExtentForSlowPathCall.h"
#include "VM.h"
namespace JSC {
ScratchRegisterAllocator::ScratchRegisterAllocator(const RegisterSet& usedRegisters)
: m_usedRegisters(usedRegisters)
, m_numberOfReusedRegisters(0)
{
}
ScratchRegisterAllocator::~ScratchRegisterAllocator() { }
void ScratchRegisterAllocator::lock(GPRReg reg)
{
if (reg == InvalidGPRReg)
return;
unsigned index = GPRInfo::toIndex(reg);
if (index == GPRInfo::InvalidIndex)
return;
m_lockedRegisters.setGPRByIndex(index);
}
void ScratchRegisterAllocator::lock(FPRReg reg)
{
if (reg == InvalidFPRReg)
return;
unsigned index = FPRInfo::toIndex(reg);
if (index == FPRInfo::InvalidIndex)
return;
m_lockedRegisters.setFPRByIndex(index);
}
void ScratchRegisterAllocator::lock(JSValueRegs regs)
{
lock(regs.tagGPR());
lock(regs.payloadGPR());
}
template<typename BankInfo>
typename BankInfo::RegisterType ScratchRegisterAllocator::allocateScratch()
{
// First try to allocate a register that is totally free.
for (unsigned i = 0; i < BankInfo::numberOfRegisters; ++i) {
typename BankInfo::RegisterType reg = BankInfo::toRegister(i);
if (!m_lockedRegisters.get(reg)
&& !m_usedRegisters.get(reg)
&& !m_scratchRegisters.get(reg)) {
m_scratchRegisters.set(reg);
return reg;
}
}
// Since that failed, try to allocate a register that is not yet
// locked or used for scratch.
for (unsigned i = 0; i < BankInfo::numberOfRegisters; ++i) {
typename BankInfo::RegisterType reg = BankInfo::toRegister(i);
if (!m_lockedRegisters.get(reg) && !m_scratchRegisters.get(reg)) {
m_scratchRegisters.set(reg);
m_numberOfReusedRegisters++;
return reg;
}
}
// We failed.
CRASH();
// Make some silly compilers happy.
return static_cast<typename BankInfo::RegisterType>(-1);
}
GPRReg ScratchRegisterAllocator::allocateScratchGPR() { return allocateScratch<GPRInfo>(); }
FPRReg ScratchRegisterAllocator::allocateScratchFPR() { return allocateScratch<FPRInfo>(); }
ScratchRegisterAllocator::PreservedState ScratchRegisterAllocator::preserveReusedRegistersByPushing(MacroAssembler& jit, ExtraStackSpace extraStackSpace)
{
if (!didReuseRegisters())
return PreservedState(0, extraStackSpace);
RegisterSet registersToSpill;
for (unsigned i = 0; i < FPRInfo::numberOfRegisters; ++i) {
FPRReg reg = FPRInfo::toRegister(i);
if (m_scratchRegisters.getFPRByIndex(i) && m_usedRegisters.get(reg))
registersToSpill.set(reg);
}
for (unsigned i = 0; i < GPRInfo::numberOfRegisters; ++i) {
GPRReg reg = GPRInfo::toRegister(i);
if (m_scratchRegisters.getGPRByIndex(i) && m_usedRegisters.get(reg))
registersToSpill.set(reg);
}
unsigned extraStackBytesAtTopOfStack = extraStackSpace == ExtraStackSpace::SpaceForCCall ? maxFrameExtentForSlowPathCall : 0;
unsigned stackAdjustmentSize = ScratchRegisterAllocator::preserveRegistersToStackForCall(jit, registersToSpill, extraStackBytesAtTopOfStack);
return PreservedState(stackAdjustmentSize, extraStackSpace);
}
void ScratchRegisterAllocator::restoreReusedRegistersByPopping(MacroAssembler& jit, const ScratchRegisterAllocator::PreservedState& preservedState)
{
RELEASE_ASSERT(preservedState);
if (!didReuseRegisters())
return;
RegisterSet registersToFill;
for (unsigned i = GPRInfo::numberOfRegisters; i--;) {
GPRReg reg = GPRInfo::toRegister(i);
if (m_scratchRegisters.getGPRByIndex(i) && m_usedRegisters.get(reg))
registersToFill.set(reg);
}
for (unsigned i = FPRInfo::numberOfRegisters; i--;) {
FPRReg reg = FPRInfo::toRegister(i);
if (m_scratchRegisters.getFPRByIndex(i) && m_usedRegisters.get(reg))
registersToFill.set(reg);
}
unsigned extraStackBytesAtTopOfStack =
preservedState.extraStackSpaceRequirement == ExtraStackSpace::SpaceForCCall ? maxFrameExtentForSlowPathCall : 0;
RegisterSet dontRestore; // Empty set. We want to restore everything.
ScratchRegisterAllocator::restoreRegistersFromStackForCall(jit, registersToFill, dontRestore,
preservedState.numberOfBytesPreserved, extraStackBytesAtTopOfStack);
}
RegisterSet ScratchRegisterAllocator::usedRegistersForCall() const
{
RegisterSet result = m_usedRegisters;
result.exclude(RegisterSet::registersToNotSaveForJSCall());
return result;
}
unsigned ScratchRegisterAllocator::desiredScratchBufferSizeForCall() const
{
return usedRegistersForCall().numberOfSetRegisters() * sizeof(JSValue);
}
void ScratchRegisterAllocator::preserveUsedRegistersToScratchBufferForCall(MacroAssembler& jit, ScratchBuffer* scratchBuffer, GPRReg scratchGPR)
{
RegisterSet usedRegisters = usedRegistersForCall();
if (!usedRegisters.numberOfSetRegisters())
return;
unsigned count = 0;
for (GPRReg reg = MacroAssembler::firstRegister(); reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
if (usedRegisters.get(reg)) {
jit.storePtr(reg, static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer()) + count);
count++;
}
if (GPRInfo::toIndex(reg) != GPRInfo::InvalidIndex
&& scratchGPR == InvalidGPRReg
&& !m_lockedRegisters.get(reg) && !m_scratchRegisters.get(reg))
scratchGPR = reg;
}
RELEASE_ASSERT(scratchGPR != InvalidGPRReg);
for (FPRReg reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
if (usedRegisters.get(reg)) {
jit.move(MacroAssembler::TrustedImmPtr(static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer()) + count), scratchGPR);
count++;
jit.storeDouble(reg, scratchGPR);
}
}
RELEASE_ASSERT(count * sizeof(JSValue) == desiredScratchBufferSizeForCall());
jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->addressOfActiveLength()), scratchGPR);
jit.storePtr(MacroAssembler::TrustedImmPtr(static_cast<size_t>(count * sizeof(JSValue))), scratchGPR);
}
void ScratchRegisterAllocator::restoreUsedRegistersFromScratchBufferForCall(MacroAssembler& jit, ScratchBuffer* scratchBuffer, GPRReg scratchGPR)
{
RegisterSet usedRegisters = usedRegistersForCall();
if (!usedRegisters.numberOfSetRegisters())
return;
if (scratchGPR == InvalidGPRReg) {
// Find a scratch register.
for (unsigned i = GPRInfo::numberOfRegisters; i--;) {
if (m_lockedRegisters.getGPRByIndex(i) || m_scratchRegisters.getGPRByIndex(i))
continue;
scratchGPR = GPRInfo::toRegister(i);
break;
}
}
RELEASE_ASSERT(scratchGPR != InvalidGPRReg);
jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->addressOfActiveLength()), scratchGPR);
jit.storePtr(MacroAssembler::TrustedImmPtr(nullptr), scratchGPR);
// Restore double registers first.
unsigned count = usedRegisters.numberOfSetGPRs();
for (FPRReg reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
if (usedRegisters.get(reg)) {
jit.move(MacroAssembler::TrustedImmPtr(static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer()) + (count++)), scratchGPR);
jit.loadDouble(scratchGPR, reg);
}
}
count = 0;
for (GPRReg reg = MacroAssembler::firstRegister(); reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
if (usedRegisters.get(reg))
jit.loadPtr(static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer()) + (count++), reg);
}
}
unsigned ScratchRegisterAllocator::preserveRegistersToStackForCall(MacroAssembler& jit, const RegisterSet& usedRegisters, unsigned extraBytesAtTopOfStack)
{
RELEASE_ASSERT(extraBytesAtTopOfStack % sizeof(void*) == 0);
if (!usedRegisters.numberOfSetRegisters())
return 0;
unsigned stackOffset = (usedRegisters.numberOfSetRegisters()) * sizeof(EncodedJSValue);
stackOffset += extraBytesAtTopOfStack;
stackOffset = WTF::roundUpToMultipleOf(stackAlignmentBytes(), stackOffset);
jit.subPtr(
MacroAssembler::TrustedImm32(stackOffset),
MacroAssembler::stackPointerRegister);
unsigned count = 0;
for (GPRReg reg = MacroAssembler::firstRegister(); reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
if (usedRegisters.get(reg)) {
jit.storePtr(reg, MacroAssembler::Address(MacroAssembler::stackPointerRegister, extraBytesAtTopOfStack + (count * sizeof(EncodedJSValue))));
count++;
}
}
for (FPRReg reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
if (usedRegisters.get(reg)) {
jit.storeDouble(reg, MacroAssembler::Address(MacroAssembler::stackPointerRegister, extraBytesAtTopOfStack + (count * sizeof(EncodedJSValue))));
count++;
}
}
RELEASE_ASSERT(count == usedRegisters.numberOfSetRegisters());
return stackOffset;
}
void ScratchRegisterAllocator::restoreRegistersFromStackForCall(MacroAssembler& jit, const RegisterSet& usedRegisters, const RegisterSet& ignore, unsigned numberOfStackBytesUsedForRegisterPreservation, unsigned extraBytesAtTopOfStack)
{
RELEASE_ASSERT(extraBytesAtTopOfStack % sizeof(void*) == 0);
if (!usedRegisters.numberOfSetRegisters()) {
RELEASE_ASSERT(numberOfStackBytesUsedForRegisterPreservation == 0);
return;
}
unsigned count = 0;
for (GPRReg reg = MacroAssembler::firstRegister(); reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
if (usedRegisters.get(reg)) {
if (!ignore.get(reg))
jit.loadPtr(MacroAssembler::Address(MacroAssembler::stackPointerRegister, extraBytesAtTopOfStack + (sizeof(EncodedJSValue) * count)), reg);
count++;
}
}
for (FPRReg reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
if (usedRegisters.get(reg)) {
if (!ignore.get(reg))
jit.loadDouble(MacroAssembler::Address(MacroAssembler::stackPointerRegister, extraBytesAtTopOfStack + (sizeof(EncodedJSValue) * count)), reg);
count++;
}
}
unsigned stackOffset = (usedRegisters.numberOfSetRegisters()) * sizeof(EncodedJSValue);
stackOffset += extraBytesAtTopOfStack;
stackOffset = WTF::roundUpToMultipleOf(stackAlignmentBytes(), stackOffset);
RELEASE_ASSERT(count == usedRegisters.numberOfSetRegisters());
RELEASE_ASSERT(stackOffset == numberOfStackBytesUsedForRegisterPreservation);
jit.addPtr(
MacroAssembler::TrustedImm32(stackOffset),
MacroAssembler::stackPointerRegister);
}
} // namespace JSC
#endif // ENABLE(JIT)