diff options
Diffstat (limited to 'lib/CodeGen/LiveIntervalAnalysis.cpp')
| -rw-r--r-- | lib/CodeGen/LiveIntervalAnalysis.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index 4d73b50924..8806439f54 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -745,8 +745,16 @@ unsigned LiveIntervals::getVNInfoSourceReg(const VNInfo *VNI) const { if (VNI->getCopy()->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) { // If it's extracting out of a physical register, return the sub-register. unsigned Reg = VNI->getCopy()->getOperand(1).getReg(); - if (TargetRegisterInfo::isPhysicalRegister(Reg)) + if (TargetRegisterInfo::isPhysicalRegister(Reg)) { + unsigned SrcSubReg = VNI->getCopy()->getOperand(2).getImm(); + unsigned DstSubReg = VNI->getCopy()->getOperand(0).getSubReg(); + if (SrcSubReg == DstSubReg) + // %reg1034:3<def> = EXTRACT_SUBREG %EDX, 3 + // reg1034 can still be coalesced to EDX. + return Reg; + assert(DstSubReg == 0); Reg = tri_->getSubReg(Reg, VNI->getCopy()->getOperand(2).getImm()); + } return Reg; } else if (VNI->getCopy()->getOpcode() == TargetInstrInfo::INSERT_SUBREG || VNI->getCopy()->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) |