MachineBasicBlock::iterator I,
unsigned DestReg,
const MachineInstr *Orig) const {
- MachineInstr *MI = Orig->clone();
- MI->getOperand(0).setReg(DestReg);
- MBB.insert(I, MI);
+ // MOV32r0 etc. are implemented with xor which clobbers condition code.
+ // Re-materialize them as movri instructions to avoid side effects.
+ switch (Orig->getOpcode()) {
+ case X86::MOV8r0:
+ BuildMI(MBB, I, TII.get(X86::MOV8ri), DestReg).addImm(0);
+ break;
+ case X86::MOV16r0:
+ BuildMI(MBB, I, TII.get(X86::MOV16ri), DestReg).addImm(0);
+ break;
+ case X86::MOV32r0:
+ BuildMI(MBB, I, TII.get(X86::MOV32ri), DestReg).addImm(0);
+ break;
+ case X86::MOV64r0:
+ BuildMI(MBB, I, TII.get(X86::MOV64ri32), DestReg).addImm(0);
+ break;
+ default: {
+ MachineInstr *MI = Orig->clone();
+ MI->getOperand(0).setReg(DestReg);
+ MBB.insert(I, MI);
+ break;
+ }
+ }
}
static const MachineInstrBuilder &FuseInstrAddOperand(MachineInstrBuilder &MIB,