ScratchRegisterAllocator.h [plain text]
#ifndef ScratchRegisterAllocator_h
#define ScratchRegisterAllocator_h
#if ENABLE(JIT)
#include "MacroAssembler.h"
#include "RegisterSet.h"
#include "TempRegisterSet.h"
namespace JSC {
struct ScratchBuffer;
class ScratchRegisterAllocator {
public:
ScratchRegisterAllocator() { }
ScratchRegisterAllocator(const RegisterSet& usedRegisters);
~ScratchRegisterAllocator();
void lock(GPRReg);
void lock(FPRReg);
void lock(JSValueRegs);
template<typename BankInfo>
typename BankInfo::RegisterType allocateScratch();
GPRReg allocateScratchGPR();
FPRReg allocateScratchFPR();
bool didReuseRegisters() const
{
return !!m_numberOfReusedRegisters;
}
unsigned numberOfReusedRegisters() const
{
return m_numberOfReusedRegisters;
}
RegisterSet usedRegisters() const { return m_usedRegisters; }
enum class ExtraStackSpace { SpaceForCCall, NoExtraSpace };
struct PreservedState {
PreservedState()
: numberOfBytesPreserved(std::numeric_limits<unsigned>::max())
, extraStackSpaceRequirement(ExtraStackSpace::SpaceForCCall)
{ }
PreservedState(unsigned numberOfBytes, ExtraStackSpace extraStackSpace)
: numberOfBytesPreserved(numberOfBytes)
, extraStackSpaceRequirement(extraStackSpace)
{ }
explicit operator bool() const { return numberOfBytesPreserved != std::numeric_limits<unsigned>::max(); }
unsigned numberOfBytesPreserved;
ExtraStackSpace extraStackSpaceRequirement;
};
PreservedState preserveReusedRegistersByPushing(MacroAssembler& jit, ExtraStackSpace);
void restoreReusedRegistersByPopping(MacroAssembler& jit, const PreservedState&);
RegisterSet usedRegistersForCall() const;
unsigned desiredScratchBufferSizeForCall() const;
void preserveUsedRegistersToScratchBufferForCall(MacroAssembler& jit, ScratchBuffer* scratchBuffer, GPRReg scratchGPR = InvalidGPRReg);
void restoreUsedRegistersFromScratchBufferForCall(MacroAssembler& jit, ScratchBuffer* scratchBuffer, GPRReg scratchGPR = InvalidGPRReg);
static unsigned preserveRegistersToStackForCall(MacroAssembler& jit, const RegisterSet& usedRegisters, unsigned extraPaddingInBytes);
static void restoreRegistersFromStackForCall(MacroAssembler& jit, const RegisterSet& usedRegisters, const RegisterSet& ignore, unsigned numberOfStackBytesUsedForRegisterPreservation, unsigned extraPaddingInBytes);
private:
RegisterSet m_usedRegisters;
TempRegisterSet m_lockedRegisters;
TempRegisterSet m_scratchRegisters;
unsigned m_numberOfReusedRegisters;
};
}
#endif // ENABLE(JIT)
#endif // ScratchRegisterAllocator_h