Commit 5945e5f2 authored by Dylan McKay's avatar Dylan McKay
Browse files

Merging r314898: 

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r314898 | dylanmckay | 2017-10-04 23:37:22 +1300 (Wed, 04 Oct 2017) | 6 lines

[AVR] Implement LPMWRdZ pseudo-instruction's expansion.

FIXME: implementation is mostly copy-pasted from LDWRdPtr, so we should
refactor a bit and unify the two

Patch by Gerdo Erdi.
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llvm-svn: 315836
parent c201f241

llvm/lib/Target/AVR/AVRExpandPseudoInsts.cpp

+44 −1
Original line number Diff line number Diff line
@@ -743,7 +743,50 @@ bool AVRExpandPseudo::expand<AVR::LDDWRdPtrQ>(Block &MBB, BlockIt MBBI) { 


template <>

bool AVRExpandPseudo::expand<AVR::LPMWRdZ>(Block &MBB, BlockIt MBBI) {

  llvm_unreachable("wide LPM is unimplemented");

  MachineInstr &MI = *MBBI;

  unsigned OpLo, OpHi, DstLoReg, DstHiReg;

  unsigned DstReg = MI.getOperand(0).getReg();

  unsigned TmpReg = 0; // 0 for no temporary register

  unsigned SrcReg = MI.getOperand(1).getReg();

  bool SrcIsKill = MI.getOperand(1).isKill();

  OpLo = AVR::LPMRdZPi;

  OpHi = AVR::LPMRdZ;

  TRI->splitReg(DstReg, DstLoReg, DstHiReg);



  // Use a temporary register if src and dst registers are the same.

  if (DstReg == SrcReg)

    TmpReg = scavengeGPR8(MI);



  unsigned CurDstLoReg = (DstReg == SrcReg) ? TmpReg : DstLoReg;

  unsigned CurDstHiReg = (DstReg == SrcReg) ? TmpReg : DstHiReg;



  // Load low byte.

  auto MIBLO = buildMI(MBB, MBBI, OpLo)

      .addReg(CurDstLoReg, RegState::Define)

      .addReg(SrcReg);



  // Push low byte onto stack if necessary.

  if (TmpReg)

    buildMI(MBB, MBBI, AVR::PUSHRr).addReg(TmpReg);



  // Load high byte.

  auto MIBHI = buildMI(MBB, MBBI, OpHi)

      .addReg(CurDstHiReg, RegState::Define)

      .addReg(SrcReg, getKillRegState(SrcIsKill));



  if (TmpReg) {

    // Move the high byte into the final destination.

    buildMI(MBB, MBBI, AVR::MOVRdRr).addReg(DstHiReg).addReg(TmpReg);



    // Move the low byte from the scratch space into the final destination.

    buildMI(MBB, MBBI, AVR::POPRd).addReg(DstLoReg);

  }



  MIBLO->setMemRefs(MI.memoperands_begin(), MI.memoperands_end());

  MIBHI->setMemRefs(MI.memoperands_begin(), MI.memoperands_end());



  MI.eraseFromParent();

  return true;

}



template <>