diff options
Diffstat (limited to 'lib/CodeGen/TwoAddressInstructionPass.cpp')
| -rw-r--r-- | lib/CodeGen/TwoAddressInstructionPass.cpp | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp index 52ea87231ccd..f54d879759ff 100644 --- a/lib/CodeGen/TwoAddressInstructionPass.cpp +++ b/lib/CodeGen/TwoAddressInstructionPass.cpp @@ -1125,6 +1125,7 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { break; // The tied operands have been eliminated. } + bool IsEarlyClobber = false; bool RemovedKillFlag = false; bool AllUsesCopied = true; unsigned LastCopiedReg = 0; @@ -1132,7 +1133,11 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { for (unsigned tpi = 0, tpe = TiedPairs.size(); tpi != tpe; ++tpi) { unsigned SrcIdx = TiedPairs[tpi].first; unsigned DstIdx = TiedPairs[tpi].second; - unsigned regA = mi->getOperand(DstIdx).getReg(); + + const MachineOperand &DstMO = mi->getOperand(DstIdx); + unsigned regA = DstMO.getReg(); + IsEarlyClobber |= DstMO.isEarlyClobber(); + // Grab regB from the instruction because it may have changed if the // instruction was commuted. regB = mi->getOperand(SrcIdx).getReg(); @@ -1196,15 +1201,17 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { } if (AllUsesCopied) { - // Replace other (un-tied) uses of regB with LastCopiedReg. - for (unsigned i = 0, e = mi->getNumOperands(); i != e; ++i) { - MachineOperand &MO = mi->getOperand(i); - if (MO.isReg() && MO.getReg() == regB && MO.isUse()) { - if (MO.isKill()) { - MO.setIsKill(false); - RemovedKillFlag = true; + if (!IsEarlyClobber) { + // Replace other (un-tied) uses of regB with LastCopiedReg. + for (unsigned i = 0, e = mi->getNumOperands(); i != e; ++i) { + MachineOperand &MO = mi->getOperand(i); + if (MO.isReg() && MO.getReg() == regB && MO.isUse()) { + if (MO.isKill()) { + MO.setIsKill(false); + RemovedKillFlag = true; + } + MO.setReg(LastCopiedReg); } - MO.setReg(LastCopiedReg); } } |