const MachineFunction &MF,
const VirtRegMap *VRM = nullptr) const;
- /// avoidWriteAfterWrite - Return true if the register allocator should avoid
- /// writing a register from RC in two consecutive instructions.
- /// This can avoid pipeline stalls on certain architectures.
- /// It does cause increased register pressure, though.
- virtual bool avoidWriteAfterWrite(const TargetRegisterClass *RC) const {
- return false;
- }
-
/// updateRegAllocHint - A callback to allow target a chance to update
/// register allocation hints when a register is "changed" (e.g. coalesced)
/// to another register. e.g. On ARM, some virtual registers should target
}
}
-bool
-ARMBaseRegisterInfo::avoidWriteAfterWrite(const TargetRegisterClass *RC) const {
- // CortexA9 has a Write-after-write hazard for NEON registers.
- if (!STI.isLikeA9())
- return false;
-
- switch (RC->getID()) {
- case ARM::DPRRegClassID:
- case ARM::DPR_8RegClassID:
- case ARM::DPR_VFP2RegClassID:
- case ARM::QPRRegClassID:
- case ARM::QPR_8RegClassID:
- case ARM::QPR_VFP2RegClassID:
- case ARM::SPRRegClassID:
- case ARM::SPR_8RegClassID:
- // Avoid reusing S, D, and Q registers.
- // Don't increase register pressure for QQ and QQQQ.
- return true;
- default:
- return false;
- }
-}
-
bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
void updateRegAllocHint(unsigned Reg, unsigned NewReg,
MachineFunction &MF) const override;
- bool avoidWriteAfterWrite(const TargetRegisterClass *RC) const override;
-
bool hasBasePointer(const MachineFunction &MF) const;
bool canRealignStack(const MachineFunction &MF) const;