diff options
Diffstat (limited to 'lib/CodeGen/DeadMachineInstructionElim.cpp')
| -rw-r--r-- | lib/CodeGen/DeadMachineInstructionElim.cpp | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/lib/CodeGen/DeadMachineInstructionElim.cpp b/lib/CodeGen/DeadMachineInstructionElim.cpp index 786de1b..fdc1d91 100644 --- a/lib/CodeGen/DeadMachineInstructionElim.cpp +++ b/lib/CodeGen/DeadMachineInstructionElim.cpp @@ -54,6 +54,12 @@ FunctionPass *llvm::createDeadMachineInstructionElimPass() { } bool DeadMachineInstructionElim::isDead(const MachineInstr *MI) const { + // Technically speaking inline asm without side effects and no defs can still + // be deleted. But there is so much bad inline asm code out there, we should + // let them be. + if (MI->isInlineAsm()) + return false; + // Don't delete instructions with side effects. bool SawStore = false; if (!MI->isSafeToMove(TII, 0, SawStore) && !MI->isPHI()) @@ -153,7 +159,7 @@ bool DeadMachineInstructionElim::runOnMachineFunction(MachineFunction &MF) { const MachineOperand &MO = MI->getOperand(i); if (MO.isReg() && MO.isDef()) { unsigned Reg = MO.getReg(); - if (Reg != 0 && TargetRegisterInfo::isPhysicalRegister(Reg)) { + if (TargetRegisterInfo::isPhysicalRegister(Reg)) { LivePhysRegs.reset(Reg); // Check the subreg set, not the alias set, because a def // of a super-register may still be partially live after @@ -170,7 +176,7 @@ bool DeadMachineInstructionElim::runOnMachineFunction(MachineFunction &MF) { const MachineOperand &MO = MI->getOperand(i); if (MO.isReg() && MO.isUse()) { unsigned Reg = MO.getReg(); - if (Reg != 0 && TargetRegisterInfo::isPhysicalRegister(Reg)) { + if (TargetRegisterInfo::isPhysicalRegister(Reg)) { LivePhysRegs.set(Reg); for (const unsigned *AliasSet = TRI->getAliasSet(Reg); *AliasSet; ++AliasSet) |