diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86InstrInfo.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86InstrInfo.cpp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp index 77955a6a426..e64b2960179 100644 --- a/llvm/lib/Target/X86/X86InstrInfo.cpp +++ b/llvm/lib/Target/X86/X86InstrInfo.cpp @@ -1641,6 +1641,11 @@ X86InstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB, return Count; } +/// isHReg - Test if the given register is a physical h register. +static bool isHReg(unsigned Reg) { + return Reg == X86::AH || Reg == X86::BH || Reg == X86::CH || Reg == X86::DH; +} + bool X86InstrInfo::copyRegToReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, unsigned DestReg, unsigned SrcReg, @@ -1658,7 +1663,12 @@ bool X86InstrInfo::copyRegToReg(MachineBasicBlock &MBB, } else if (DestRC == &X86::GR16RegClass) { Opc = X86::MOV16rr; } else if (DestRC == &X86::GR8RegClass) { - Opc = X86::MOV8rr; + // Copying two or from a physical H register requires a NOREX move. Otherwise + // use a normal move. + if (isHReg(DestReg) || isHReg(SrcReg)) + Opc = X86::MOV8rr_NOREX; + else + Opc = X86::MOV8rr; } else if (DestRC == &X86::GR64_RegClass) { Opc = X86::MOV64rr; } else if (DestRC == &X86::GR32_RegClass) { |
