diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/PHIElimination.cpp | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp index a82e78e..8b1f307 100644 --- a/lib/CodeGen/PHIElimination.cpp +++ b/lib/CodeGen/PHIElimination.cpp @@ -127,11 +127,15 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) { return true; } -static bool isSourceDefinedByImplicitDef(MachineInstr *MPhi, unsigned SrcIdx, +static bool isSourceDefinedByImplicitDef(MachineInstr *MPhi, MachineRegisterInfo *MRI) { - unsigned SrcReg = MPhi->getOperand(SrcIdx*2+1).getReg(); - MachineInstr *DefMI = MRI->getVRegDef(SrcReg); - return DefMI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF; + for (unsigned i = 1; i != MPhi->getNumOperands(); i += 2) { + unsigned SrcReg = MPhi->getOperand(i).getReg(); + MachineInstr *DefMI = MRI->getVRegDef(SrcReg); + if (!DefMI || DefMI->getOpcode() != TargetInstrInfo::IMPLICIT_DEF) + return false; + } + return true; } /// LowerAtomicPHINode - Lower the PHI node at the top of the specified block, @@ -156,9 +160,9 @@ void PNE::LowerAtomicPHINode(MachineBasicBlock &MBB, // into the phi node destination. // const TargetInstrInfo *TII = MF.getTarget().getInstrInfo(); - if (NumSrcs == 1 && isSourceDefinedByImplicitDef(MPhi, 0, MRI)) - // If the only source of a PHI node is an implicit_def, just emit an - // implicit_def instead of a copy. + if (isSourceDefinedByImplicitDef(MPhi, MRI)) + // If all sources of a PHI node are implicit_def, just emit an implicit_def + // instead of a copy. BuildMI(MBB, AfterPHIsIt, TII->get(TargetInstrInfo::IMPLICIT_DEF), DestReg); else TII->copyRegToReg(MBB, AfterPHIsIt, DestReg, IncomingReg, RC, RC); |