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MIPS: Implement isAsCheapAsAMove for addiu #133273

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Merged
merged 1 commit into from
Mar 28, 2025
Merged

MIPS: Implement isAsCheapAsAMove for addiu #133273

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16 changes: 16 additions & 0 deletions llvm/lib/Target/Mips/MipsInstrInfo.cpp
View file
Original file line number Diff line number Diff line change
@@ -678,6 +678,22 @@ bool MipsInstrInfo::HasLoadDelaySlot(const MachineInstr &MI) const {
}
}

bool MipsInstrInfo::isAsCheapAsAMove(const MachineInstr &MI) const {
const unsigned Opcode = MI.getOpcode();
switch (Opcode) {
default:
break;
case Mips::ADDiu:
case Mips::ADDiu_MM:
case Mips::DADDiu:
return ((MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0) ||
(MI.getOperand(1).isReg() &&
(MI.getOperand(1).getReg() == Mips::ZERO ||
MI.getOperand(1).getReg() == Mips::ZERO_64)));
}
return MI.isAsCheapAsAMove();
}

/// Return the number of bytes of code the specified instruction may be.
unsigned MipsInstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
switch (MI.getOpcode()) {
2 changes: 2 additions & 0 deletions llvm/lib/Target/Mips/MipsInstrInfo.h
View file
Original file line number Diff line number Diff line change
@@ -113,6 +113,8 @@ class MipsInstrInfo : public MipsGenInstrInfo {
/// Predicate to determine if an instruction has a load delay slot.
bool HasLoadDelaySlot(const MachineInstr &MI) const;

bool isAsCheapAsAMove(const MachineInstr &MI) const override;

/// Insert nop instruction when hazard condition is found
void insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override;