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[PowerPC][NFC] Update lowering STXVP to STXV in Oct word spilling (Part 2) #143952

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[PowerPC][NFC] Update lowering STXVP to STXV in Oct word spilling (Part 2) #143952

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4681ce5
Revert "[PowerPC][NFC] Update lowering STXVP to STXV in Oct word spil…
lei137 Jun 12, 2025
63c233d
Simpliy handling for spilling of acc reg with stx by removing
lei137 May 30, 2025
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61 changes: 32 additions & 29 deletions llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1238,6 +1238,30 @@ static void emitAccSpillRestoreInfo(MachineBasicBlock &MBB, bool IsPrimed,
#endif
}

void PPCRegisterInfo::spillRegPair(MachineBasicBlock &MBB,
MachineBasicBlock::iterator II, DebugLoc DL,
const TargetInstrInfo &TII,
unsigned FrameIndex, bool IsLittleEndian,
bool IsKilled, Register Reg,
int Offset) const {

// This function does not support virtual registers.
assert(!Reg.isVirtual() &&
"Spilling register pairs does not support virtual registers.");

addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXV))
.addReg(TargetRegisterInfo::getSubReg(Reg, PPC::sub_vsx0),
getKillRegState(IsKilled)),
FrameIndex, Offset);

addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXV))
.addReg(TargetRegisterInfo::getSubReg(Reg, PPC::sub_vsx1),
getKillRegState(IsKilled)),
FrameIndex, IsLittleEndian ? Offset - 16 : Offset + 16);
}

/// Remove any STXVP[X] instructions and split them out into a pair of
/// STXV[X] instructions if --disable-auto-paired-vec-st is specified on
/// the command line.
Expand All @@ -1255,19 +1279,8 @@ void PPCRegisterInfo::lowerOctWordSpilling(MachineBasicBlock::iterator II,
bool IsLittleEndian = Subtarget.isLittleEndian();
bool IsKilled = MI.getOperand(0).isKill();

assert(PPC::VSRpRCRegClass.contains(SrcReg) &&
"Expecting STXVP to be utilizing a VSRp register.");

addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXV))
.addReg(TargetRegisterInfo::getSubReg(SrcReg, PPC::sub_vsx0),
getKillRegState(IsKilled)),
FrameIndex, IsLittleEndian ? 16 : 0);
addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXV))
.addReg(TargetRegisterInfo::getSubReg(SrcReg, PPC::sub_vsx1),
getKillRegState(IsKilled)),
FrameIndex, IsLittleEndian ? 0 : 16);
spillRegPair(MBB, II, DL, TII, FrameIndex, IsLittleEndian, IsKilled, SrcReg,
IsLittleEndian ? 16 : 0);

// Discard the original instruction.
MBB.erase(II);
Expand Down Expand Up @@ -1313,22 +1326,12 @@ void PPCRegisterInfo::lowerACCSpilling(MachineBasicBlock::iterator II,
if (IsPrimed)
BuildMI(MBB, II, DL, TII.get(PPC::XXMFACC), SrcReg).addReg(SrcReg);
if (DisableAutoPairedVecSt) {
auto spillPair = [&](Register Reg, int Offset) {
addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXV))
.addReg(TargetRegisterInfo::getSubReg(Reg, PPC::sub_vsx0),
getKillRegState(IsKilled)),
FrameIndex, Offset);
addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXV))
.addReg(TargetRegisterInfo::getSubReg(Reg, PPC::sub_vsx1),
getKillRegState(IsKilled)),
FrameIndex, IsLittleEndian ? Offset - 16 : Offset + 16);
};
spillPair(TargetRegisterInfo::getSubReg(SrcReg, PPC::sub_pair0),
IsLittleEndian ? 48 : 0);
spillPair(TargetRegisterInfo::getSubReg(SrcReg, PPC::sub_pair1),
IsLittleEndian ? 16 : 32);
spillRegPair(MBB, II, DL, TII, FrameIndex, IsLittleEndian, IsKilled,
TargetRegisterInfo::getSubReg(SrcReg, PPC::sub_pair0),
IsLittleEndian ? 48 : 0);
spillRegPair(MBB, II, DL, TII, FrameIndex, IsLittleEndian, IsKilled,
TargetRegisterInfo::getSubReg(SrcReg, PPC::sub_pair1),
IsLittleEndian ? 16 : 32);
} else {
addFrameReference(
BuildMI(MBB, II, DL, TII.get(PPC::STXVP))
Expand Down
5 changes: 5 additions & 0 deletions llvm/lib/Target/PowerPC/PPCRegisterInfo.h
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Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,11 @@ class PPCRegisterInfo : public PPCGenRegisterInfo {
DenseMap<unsigned, unsigned> ImmToIdxMap;
const PPCTargetMachine &TM;

void spillRegPair(MachineBasicBlock &MBB, MachineBasicBlock::iterator II,
DebugLoc DL, const TargetInstrInfo &TII,
unsigned FrameIndex, bool IsLittleEndian, bool IsKilled,
Register Reg, int Offset) const;

public:
PPCRegisterInfo(const PPCTargetMachine &TM);

Expand Down