diff options
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 12 | ||||
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.td | 13 |
2 files changed, 20 insertions, 5 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index 77955a6a42..e64b296017 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/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) { diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td index 077b4563b0..4fd3320090 100644 --- a/lib/Target/X86/X86InstrInfo.td +++ b/lib/Target/X86/X86InstrInfo.td @@ -783,10 +783,15 @@ def MOV32mr : I<0x89, MRMDestMem, (outs), (ins i32mem:$dst, GR32:$src), "mov{l}\t{$src, $dst|$dst, $src}", [(store GR32:$src, addr:$dst)]>; -// A version of MOV8mr that uses i8mem_NOREX so that it can be used for -// storing h registers, which can't be encoded when a REX prefix is present. -def MOV8mr_NOREX : I<0x88, MRMDestMem, (outs), (ins i8mem_NOREX:$dst, GR8:$src), - "mov{b}\t{$src, $dst|$dst, $src} # NOREX", []>; +// Versions of MOV8rr and MOV8mr that use i8mem_NOREX and GR8_NOREX so that they +// can be used for copying and storing h registers, which can't be encoded when +// a REX prefix is present. +let neverHasSideEffects = 1 in +def MOV8rr_NOREX : I<0x88, MRMDestReg, (outs GR8_NOREX:$dst), (ins GR8_NOREX:$src), + "mov{b}\t{$src, $dst|$dst, $src} # NOREX", []>; +def MOV8mr_NOREX : I<0x88, MRMDestMem, + (outs), (ins i8mem_NOREX:$dst, GR8_NOREX:$src), + "mov{b}\t{$src, $dst|$dst, $src} # NOREX", []>; //===----------------------------------------------------------------------===// // Fixed-Register Multiplication and Division Instructions... |