--- /dev/null
+/*
+ * Copyright (C) 2014 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 "JSCInlines.h"
+#include "VM.h"
+
+namespace JSC {
+
+ScratchRegisterAllocator::ScratchRegisterAllocator(const RegisterSet& usedRegisters)
+ : m_usedRegisters(usedRegisters)
+ , m_numberOfReusedRegisters(0)
+{
+}
+
+ScratchRegisterAllocator::~ScratchRegisterAllocator() { }
+
+void ScratchRegisterAllocator::lock(GPRReg reg)
+{
+ unsigned index = GPRInfo::toIndex(reg);
+ if (index == GPRInfo::InvalidIndex)
+ return;
+ m_lockedRegisters.setGPRByIndex(index);
+}
+
+void ScratchRegisterAllocator::lock(FPRReg reg)
+{
+ unsigned index = FPRInfo::toIndex(reg);
+ if (index == FPRInfo::InvalidIndex)
+ return;
+ m_lockedRegisters.setFPRByIndex(index);
+}
+
+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>(); }
+
+void ScratchRegisterAllocator::preserveReusedRegistersByPushing(MacroAssembler& jit)
+{
+ if (!didReuseRegisters())
+ return;
+
+ for (unsigned i = 0; i < FPRInfo::numberOfRegisters; ++i) {
+ FPRReg reg = FPRInfo::toRegister(i);
+ if (m_scratchRegisters.getFPRByIndex(i) && m_usedRegisters.get(reg))
+ jit.pushToSave(reg);
+ }
+ for (unsigned i = 0; i < GPRInfo::numberOfRegisters; ++i) {
+ GPRReg reg = GPRInfo::toRegister(i);
+ if (m_scratchRegisters.getGPRByIndex(i) && m_usedRegisters.get(reg))
+ jit.pushToSave(reg);
+ }
+}
+
+void ScratchRegisterAllocator::restoreReusedRegistersByPopping(MacroAssembler& jit)
+{
+ if (!didReuseRegisters())
+ return;
+
+ for (unsigned i = GPRInfo::numberOfRegisters; i--;) {
+ GPRReg reg = GPRInfo::toRegister(i);
+ if (m_scratchRegisters.getGPRByIndex(i) && m_usedRegisters.get(reg))
+ jit.popToRestore(reg);
+ }
+ for (unsigned i = FPRInfo::numberOfRegisters; i--;) {
+ FPRReg reg = FPRInfo::toRegister(i);
+ if (m_scratchRegisters.getFPRByIndex(i) && m_usedRegisters.get(reg))
+ jit.popToRestore(reg);
+ }
+}
+
+RegisterSet ScratchRegisterAllocator::usedRegistersForCall() const
+{
+ RegisterSet result = m_usedRegisters;
+ result.exclude(RegisterSet::calleeSaveRegisters());
+ result.exclude(RegisterSet::stackRegisters());
+ result.exclude(RegisterSet::reservedHardwareRegisters());
+ 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++));
+ 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);
+ jit.storeDouble(reg, scratchGPR);
+ }
+ }
+ RELEASE_ASSERT(count * sizeof(JSValue) == desiredScratchBufferSizeForCall());
+
+ jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), 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->activeLengthPtr()), scratchGPR);
+ jit.storePtr(MacroAssembler::TrustedImmPtr(0), 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);
+ }
+}
+
+} // namespace JSC
+
+#endif // ENABLE(JIT)
projects / apple / javascriptcore.git / blobdiff