}
}
- // Prevent use of AH in a REX instruction by referencing AX instead.
- if (HiReg == X86::AH && Subtarget->is64Bit() &&
- !SDValue(Node, 1).use_empty()) {
- SDValue Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), dl,
- X86::AX, MVT::i16, InFlag);
- InFlag = Result.getValue(2);
- // Get the low part if needed. Don't use getCopyFromReg for aliasing
- // registers.
- if (!SDValue(Node, 0).use_empty())
- ReplaceUses(SDValue(Node, 0),
- CurDAG->getTargetExtractSubreg(X86::sub_8bit, dl, MVT::i8, Result));
-
- // Shift AX down 8 bits.
- Result = SDValue(CurDAG->getMachineNode(X86::SHR16ri, dl, MVT::i16,
- Result,
- CurDAG->getTargetConstant(8, dl, MVT::i8)),
- 0);
- // Then truncate it down to i8.
- ReplaceUses(SDValue(Node, 1),
- CurDAG->getTargetExtractSubreg(X86::sub_8bit, dl, MVT::i8, Result));
- }
// Copy the low half of the result, if it is needed.
if (!SDValue(Node, 0).use_empty()) {
if (!ResLo.getNode()) {