diff options
Diffstat (limited to 'lib/Target/PowerPC/PPCInstrInfo.cpp')
| -rw-r--r-- | lib/Target/PowerPC/PPCInstrInfo.cpp | 814 |
1 files changed, 814 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp index 15e457543a9..a9060b41794 100644 --- a/lib/Target/PowerPC/PPCInstrInfo.cpp +++ b/lib/Target/PowerPC/PPCInstrInfo.cpp @@ -51,6 +51,10 @@ STATISTIC(NumStoreSPILLVSRRCAsVec, STATISTIC(NumStoreSPILLVSRRCAsGpr, "Number of spillvsrrc spilled to stack as gpr"); STATISTIC(NumGPRtoVSRSpill, "Number of gpr spills to spillvsrrc"); +STATISTIC(CmpIselsConverted, + "Number of ISELs that depend on comparison of constants converted"); +STATISTIC(MissedConvertibleImmediateInstrs, + "Number of compare-immediate instructions fed by constants"); static cl:: opt<bool> DisableCTRLoopAnal("disable-ppc-ctrloop-analysis", cl::Hidden, @@ -2147,6 +2151,816 @@ bool PPCInstrInfo::expandPostRAPseudo(MachineInstr &MI) const { return false; } +unsigned PPCInstrInfo::lookThruCopyLike(unsigned SrcReg, + const MachineRegisterInfo *MRI) { + while (true) { + MachineInstr *MI = MRI->getVRegDef(SrcReg); + if (!MI->isCopyLike()) + return SrcReg; + + unsigned CopySrcReg; + if (MI->isCopy()) + CopySrcReg = MI->getOperand(1).getReg(); + else { + assert(MI->isSubregToReg() && "Bad opcode for lookThruCopyLike"); + CopySrcReg = MI->getOperand(2).getReg(); + } + + if (!TargetRegisterInfo::isVirtualRegister(CopySrcReg)) + return CopySrcReg; + + SrcReg = CopySrcReg; + } +} + +// Essentially a compile-time implementation of a compare->isel sequence. +// It takes two constants to compare, along with the true/false registers +// and the comparison type (as a subreg to a CR field) and returns one +// of the true/false registers, depending on the comparison results. +static unsigned selectReg(int64_t Imm1, int64_t Imm2, unsigned CompareOpc, + unsigned TrueReg, unsigned FalseReg, + unsigned CRSubReg) { + // Signed comparisons. The immediates are assumed to be sign-extended. + if (CompareOpc == PPC::CMPWI || CompareOpc == PPC::CMPDI) { + switch (CRSubReg) { + default: llvm_unreachable("Unknown integer comparison type."); + case PPC::sub_lt: + return Imm1 < Imm2 ? TrueReg : FalseReg; + case PPC::sub_gt: + return Imm1 > Imm2 ? TrueReg : FalseReg; + case PPC::sub_eq: + return Imm1 == Imm2 ? TrueReg : FalseReg; + } + } + // Unsigned comparisons. + else if (CompareOpc == PPC::CMPLWI || CompareOpc == PPC::CMPLDI) { + switch (CRSubReg) { + default: llvm_unreachable("Unknown integer comparison type."); + case PPC::sub_lt: + return (uint64_t)Imm1 < (uint64_t)Imm2 ? TrueReg : FalseReg; + case PPC::sub_gt: + return (uint64_t)Imm1 > (uint64_t)Imm2 ? TrueReg : FalseReg; + case PPC::sub_eq: + return Imm1 == Imm2 ? TrueReg : FalseReg; + } + } + return PPC::NoRegister; +} + +// Replace an instruction with one that materializes a constant (and sets +// CR0 if the original instruction was a record-form instruction). +void PPCInstrInfo::replaceInstrWithLI(MachineInstr &MI, + const LoadImmediateInfo &LII) const { + // Remove existing operands. + int OperandToKeep = LII.SetCR ? 1 : 0; + for (int i = MI.getNumOperands() - 1; i > OperandToKeep; i--) + MI.RemoveOperand(i); + + // Replace the instruction. + if (LII.SetCR) + MI.setDesc(get(LII.Is64Bit ? PPC::ANDIo8 : PPC::ANDIo)); + else + MI.setDesc(get(LII.Is64Bit ? PPC::LI8 : PPC::LI)); + + // Set the immediate. + MachineInstrBuilder(*MI.getParent()->getParent(), MI) + .addImm(LII.Imm); +} + +MachineInstr *PPCInstrInfo::getConstantDefMI(MachineInstr &MI, + unsigned &ConstOp, + bool &SeenIntermediateUse) const { + ConstOp = ~0U; + MachineInstr *DefMI = nullptr; + MachineRegisterInfo *MRI = &MI.getParent()->getParent()->getRegInfo(); + // If we'ere in SSA, get the defs through the MRI. Otherwise, only look + // within the basic block to see if the register is defined using an LI/LI8. + if (MRI->isSSA()) { + for (int i = 1, e = MI.getNumOperands(); i < e; i++) { + if (!MI.getOperand(i).isReg()) + continue; + unsigned Reg = MI.getOperand(i).getReg(); + if (!TargetRegisterInfo::isVirtualRegister(Reg)) + continue; + unsigned TrueReg = lookThruCopyLike(Reg, MRI); + if (TargetRegisterInfo::isVirtualRegister(TrueReg)) { + DefMI = MRI->getVRegDef(TrueReg); + if (DefMI->getOpcode() == PPC::LI || DefMI->getOpcode() == PPC::LI8) { + ConstOp = i; + break; + } + } + } + } else { + // Looking back through the definition for each operand could be expensive, + // so exit early if this isn't an instruction that either has an immediate + // form or is already an immediate form that we can handle. + ImmInstrInfo III; + unsigned Opc = MI.getOpcode(); + bool ConvertibleImmForm = + Opc == PPC::CMPWI || Opc == PPC::CMPLWI || + Opc == PPC::CMPDI || Opc == PPC::CMPLDI || + Opc == PPC::ADDI || Opc == PPC::ADDI8 || + Opc == PPC::ORI || Opc == PPC::ORI8 || + Opc == PPC::XORI || Opc == PPC::XORI8 || + Opc == PPC::RLDICL || Opc == PPC::RLDICLo || + Opc == PPC::RLDICL_32 || Opc == PPC::RLDICL_32_64 || + Opc == PPC::RLWINM || Opc == PPC::RLWINMo || + Opc == PPC::RLWINM8 || Opc == PPC::RLWINM8o; + if (!instrHasImmForm(MI, III) && !ConvertibleImmForm) + return nullptr; + + // Don't convert or %X, %Y, %Y since that's just a register move. + if ((Opc == PPC::OR || Opc == PPC::OR8) && + MI.getOperand(1).getReg() == MI.getOperand(2).getReg()) + return nullptr; + for (int i = 1, e = MI.getNumOperands(); i < e; i++) { + MachineOperand &MO = MI.getOperand(i); + SeenIntermediateUse = false; + if (MO.isReg() && MO.isUse() && !MO.isImplicit()) { + MachineBasicBlock::reverse_iterator E = MI.getParent()->rend(), It = MI; + It++; + unsigned Reg = MI.getOperand(i).getReg(); + + // Is this register defined by a load-immediate in this block? + for ( ; It != E; ++It) { + if (It->modifiesRegister(Reg, &getRegisterInfo())) { + if (It->getOpcode() == PPC::LI || It->getOpcode() == PPC::LI8) { + ConstOp = i; + return &*It; + } else + break; + } else if (It->readsRegister(Reg, &getRegisterInfo())) + // If we see another use of this reg between the def and the MI, + // we want to flat it so the def isn't deleted. + SeenIntermediateUse = true; + } + } + } + } + return ConstOp == ~0U ? nullptr : DefMI; +} + +// If this instruction has an immediate form and one of its operands is a +// result of a load-immediate, convert it to the immediate form if the constant +// is in range. +bool PPCInstrInfo::convertToImmediateForm(MachineInstr &MI, + MachineInstr **KilledDef) const { + MachineFunction *MF = MI.getParent()->getParent(); + MachineRegisterInfo *MRI = &MF->getRegInfo(); + bool PostRA = !MRI->isSSA(); + bool SeenIntermediateUse = true; + unsigned ConstantOperand = ~0U; + MachineInstr *DefMI = getConstantDefMI(MI, ConstantOperand, + SeenIntermediateUse); + if (!DefMI || !DefMI->getOperand(1).isImm()) + return false; + assert(ConstantOperand < MI.getNumOperands() && + "The constant operand needs to be valid at this point"); + + int64_t Immediate = DefMI->getOperand(1).getImm(); + // Sign-extend to 64-bits. + int64_t SExtImm = ((uint64_t)Immediate & ~0x7FFFuLL) != 0 ? + (Immediate | 0xFFFFFFFFFFFF0000) : Immediate; + + if (KilledDef && MI.getOperand(ConstantOperand).isKill() && + !SeenIntermediateUse) + *KilledDef = DefMI; + + // If this is a reg+reg instruction that has a reg+imm form, convert it now. + ImmInstrInfo III; + if (instrHasImmForm(MI, III)) + return transformToImmForm(MI, III, ConstantOperand, SExtImm); + + bool ReplaceWithLI = false; + bool Is64BitLI = false; + int64_t NewImm = 0; + bool SetCR = false; + unsigned Opc = MI.getOpcode(); + switch (Opc) { + default: return false; + + // FIXME: Any branches conditional on such a comparison can be made + // unconditional. At this time, this happens too infrequently to be worth + // the implementation effort, but if that ever changes, we could convert + // such a pattern here. + case PPC::CMPWI: + case PPC::CMPLWI: + case PPC::CMPDI: + case PPC::CMPLDI: { + // Doing this post-RA would require dataflow analysis to reliably find uses + // of the CR register set by the compare. + if (PostRA) + return false; + // If a compare-immediate is fed by an immediate and is itself an input of + // an ISEL (the most common case) into a COPY of the correct register. + bool Changed = false; + unsigned DefReg = MI.getOperand(0).getReg(); + int64_t Comparand = MI.getOperand(2).getImm(); + int64_t SExtComparand = ((uint64_t)Comparand & ~0x7FFFuLL) != 0 ? + (Comparand | 0xFFFFFFFFFFFF0000) : Comparand; + + for (auto &CompareUseMI : MRI->use_instructions(DefReg)) { + unsigned UseOpc = CompareUseMI.getOpcode(); + if (UseOpc != PPC::ISEL && UseOpc != PPC::ISEL8) + continue; + unsigned CRSubReg = CompareUseMI.getOperand(3).getSubReg(); + unsigned TrueReg = CompareUseMI.getOperand(1).getReg(); + unsigned FalseReg = CompareUseMI.getOperand(2).getReg(); + unsigned RegToCopy = selectReg(SExtImm, SExtComparand, Opc, TrueReg, + FalseReg, CRSubReg); + if (RegToCopy == PPC::NoRegister) + continue; + // Can't use PPC::COPY to copy PPC::ZERO[8]. Convert it to LI[8] 0. + if (RegToCopy == PPC::ZERO || RegToCopy == PPC::ZERO8) { + CompareUseMI.setDesc(get(UseOpc == PPC::ISEL8 ? PPC::LI8 : PPC::LI)); + CompareUseMI.getOperand(1).ChangeToImmediate(0); + CompareUseMI.RemoveOperand(3); + CompareUseMI.RemoveOperand(2); + continue; + } + DEBUG(dbgs() << "Found LI -> CMPI -> ISEL, replacing with a copy.\n"); + DEBUG(DefMI->dump(); MI.dump(); CompareUseMI.dump()); + DEBUG(dbgs() << "Is converted to:\n"); + // Convert to copy and remove unneeded operands. + CompareUseMI.setDesc(get(PPC::COPY)); + CompareUseMI.RemoveOperand(3); + CompareUseMI.RemoveOperand(RegToCopy == TrueReg ? 2 : 1); + CmpIselsConverted++; + Changed = true; + DEBUG(CompareUseMI.dump()); + } + if (Changed) + return true; + // This may end up incremented multiple times since this function is called + // during a fixed-point transformation, but it is only meant to indicate the + // presence of this opportunity. + MissedConvertibleImmediateInstrs++; + return false; + } + + // Immediate forms - may simply be convertable to an LI. + case PPC::ADDI: + case PPC::ADDI8: { + // Does the sum fit in a 16-bit signed field? + int64_t Addend = MI.getOperand(2).getImm(); + if (isInt<16>(Addend + SExtImm)) { + ReplaceWithLI = true; + Is64BitLI = Opc == PPC::ADDI8; + NewImm = Addend + SExtImm; + break; + } + } + case PPC::RLDICL: + case PPC::RLDICLo: + case PPC::RLDICL_32: + case PPC::RLDICL_32_64: { + // Use APInt's rotate function. + int64_t SH = MI.getOperand(2).getImm(); + int64_t MB = MI.getOperand(3).getImm(); + APInt InVal(Opc == PPC::RLDICL ? 64 : 32, SExtImm, true); + InVal = InVal.rotl(SH); + uint64_t Mask = (1LU << (63 - MB + 1)) - 1; + InVal &= Mask; + // Can't replace negative values with an LI as that will sign-extend + // and not clear the left bits. If we're setting the CR bit, we will use + // ANDIo which won't sign extend, so that's safe. + if (isUInt<15>(InVal.getSExtValue()) || + (Opc == PPC::RLDICLo && isUInt<16>(InVal.getSExtValue()))) { + ReplaceWithLI = true; + Is64BitLI = Opc != PPC::RLDICL_32; + NewImm = InVal.getSExtValue(); + SetCR = Opc == PPC::RLDICLo; + break; + } + return false; + } + case PPC::RLWINM: + case PPC::RLWINM8: + case PPC::RLWINMo: + case PPC::RLWINM8o: { + int64_t SH = MI.getOperand(2).getImm(); + int64_t MB = MI.getOperand(3).getImm(); + int64_t ME = MI.getOperand(4).getImm(); + APInt InVal(32, SExtImm, true); + InVal = InVal.rotl(SH); + // Set the bits ( MB + 32 ) to ( ME + 32 ). + uint64_t Mask = ((1 << (32 - MB)) - 1) & ~((1 << (31 - ME)) - 1); + InVal &= Mask; + // Can't replace negative values with an LI as that will sign-extend + // and not clear the left bits. If we're setting the CR bit, we will use + // ANDIo which won't sign extend, so that's safe. + bool ValueFits = isUInt<15>(InVal.getSExtValue()); + ValueFits |= ((Opc == PPC::RLWINMo || Opc == PPC::RLWINM8o) && + isUInt<16>(InVal.getSExtValue())); + if (ValueFits) { + ReplaceWithLI = true; + Is64BitLI = Opc == PPC::RLWINM8 || Opc == PPC::RLWINM8o; + NewImm = InVal.getSExtValue(); + SetCR = Opc == PPC::RLWINMo || Opc == PPC::RLWINM8o; + break; + } + return false; + } + case PPC::ORI: + case PPC::ORI8: + case PPC::XORI: + case PPC::XORI8: { + int64_t LogicalImm = MI.getOperand(2).getImm(); + int64_t Result = 0; + if (Opc == PPC::ORI || Opc == PPC::ORI8) + Result = LogicalImm | SExtImm; + else + Result = LogicalImm ^ SExtImm; + if (isInt<16>(Result)) { + ReplaceWithLI = true; + Is64BitLI = Opc == PPC::ORI8 || Opc == PPC::XORI8; + NewImm = Result; + break; + } + return false; + } + } + + if (ReplaceWithLI) { + DEBUG(dbgs() << "Replacing instruction:\n"); + DEBUG(MI.dump()); + DEBUG(dbgs() << "Fed by:\n"); + DEBUG(DefMI->dump()); + LoadImmediateInfo LII; + LII.Imm = NewImm; + LII.Is64Bit = Is64BitLI; + LII.SetCR = SetCR; + // If we're setting the CR, the original load-immediate must be kept (as an + // operand to ANDIo/ANDI8o). + if (KilledDef && SetCR) + *KilledDef = nullptr; + replaceInstrWithLI(MI, LII); + DEBUG(dbgs() << "With:\n"); + DEBUG(MI.dump()); + return true; + } + return false; +} + +bool PPCInstrInfo::instrHasImmForm(const MachineInstr &MI, + ImmInstrInfo &III) const { + unsigned Opc = MI.getOpcode(); + // The vast majority of the instructions would need their operand 2 replaced + // with an immediate when switching to the reg+imm form. A marked exception + // are the update form loads/stores for which a constant operand 2 would need + // to turn into a displacement and move operand 1 to the operand 2 position. + III.ImmOpNo = 2; + III.ConstantOpNo = 2; + III.ImmWidth = 16; + III.ImmMustBeMultipleOf = 1; + switch (Opc) { + default: return false; + case PPC::ADD4: + case PPC::ADD8: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 1; + III.IsCommutative = true; + III.ImmOpcode = Opc == PPC::ADD4 ? PPC::ADDI : PPC::ADDI8; + break; + case PPC::ADDC: + case PPC::ADDC8: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = true; + III.ImmOpcode = Opc == PPC::ADDC ? PPC::ADDIC : PPC::ADDIC8; + break; + case PPC::ADDCo: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = true; + III.ImmOpcode = PPC::ADDICo; + break; + case PPC::SUBFC: + case PPC::SUBFC8: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = false; + III.ImmOpcode = Opc == PPC::SUBFC ? PPC::SUBFIC : PPC::SUBFIC8; + break; + case PPC::CMPW: + case PPC::CMPD: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = false; + III.ImmOpcode = Opc == PPC::CMPW ? PPC::CMPWI : PPC::CMPDI; + break; + case PPC::CMPLW: + case PPC::CMPLD: + III.SignedImm = false; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = false; + III.ImmOpcode = Opc == PPC::CMPLW ? PPC::CMPLWI : PPC::CMPLDI; + break; + case PPC::ANDo: + case PPC::AND8o: + case PPC::OR: + case PPC::OR8: + case PPC::XOR: + case PPC::XOR8: + III.SignedImm = false; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = true; + switch(Opc) { + default: llvm_unreachable("Unknown opcode"); + case PPC::ANDo: III.ImmOpcode = PPC::ANDIo; break; + case PPC::AND8o: III.ImmOpcode = PPC::ANDIo8; break; + case PPC::OR: III.ImmOpcode = PPC::ORI; break; + case PPC::OR8: III.ImmOpcode = PPC::ORI8; break; + case PPC::XOR: III.ImmOpcode = PPC::XORI; break; + case PPC::XOR8: III.ImmOpcode = PPC::XORI8; break; + } + break; + case PPC::RLWNM: + case PPC::RLWNM8: + case PPC::RLWNMo: + case PPC::RLWNM8o: + case PPC::RLDCL: + case PPC::RLDCLo: + case PPC::RLDCR: + case PPC::RLDCRo: + case PPC::SLW: + case PPC::SLW8: + case PPC::SLWo: + case PPC::SLW8o: + case PPC::SRW: + case PPC::SRW8: + case PPC::SRWo: + case PPC::SRW8o: + case PPC::SRAW: + case PPC::SRAWo: + case PPC::SLD: + case PPC::SLDo: + case PPC::SRD: + case PPC::SRDo: + case PPC::SRAD: + case PPC::SRADo: + III.SignedImm = false; + III.ZeroIsSpecialOrig = 0; + III.ZeroIsSpecialNew = 0; + III.IsCommutative = false; + // This isn't actually true, but the instructions ignore any of the + // upper bits, so any immediate loaded with an LI is acceptable. + III.ImmWidth = 16; + switch(Opc) { + default: llvm_unreachable("Unknown opcode"); + case PPC::RLWNM: III.ImmOpcode = PPC::RLWINM; break; + case PPC::RLWNM8: III.ImmOpcode = PPC::RLWINM8; break; + case PPC::RLWNMo: III.ImmOpcode = PPC::RLWINMo; break; + case PPC::RLWNM8o: III.ImmOpcode = PPC::RLWINM8o; break; + case PPC::RLDCL: III.ImmOpcode = PPC::RLDICL; break; + case PPC::RLDCLo: III.ImmOpcode = PPC::RLDICLo; break; + case PPC::RLDCR: III.ImmOpcode = PPC::RLDICR; break; + case PPC::RLDCRo: III.ImmOpcode = PPC::RLDICRo; break; + case PPC::SLW: III.ImmOpcode = PPC::RLWINM; break; + case PPC::SLW8: III.ImmOpcode = PPC::RLWINM8; break; + case PPC::SLWo: III.ImmOpcode = PPC::RLWINMo; break; + case PPC::SLW8o: III.ImmOpcode = PPC::RLWINM8o; break; + case PPC::SRW: III.ImmOpcode = PPC::RLWINM; break; + case PPC::SRW8: III.ImmOpcode = PPC::RLWINM8; break; + case PPC::SRWo: III.ImmOpcode = PPC::RLWINMo; break; + case PPC::SRW8o: III.ImmOpcode = PPC::RLWINM8o; break; + case PPC::SRAW: III.ImmOpcode = PPC::SRAWI; break; + case PPC::SRAWo: III.ImmOpcode = PPC::SRAWIo; break; + case PPC::SLD: III.ImmOpcode = PPC::RLDICR; break; + case PPC::SLDo: III.ImmOpcode = PPC::RLDICRo; break; + case PPC::SRD: III.ImmOpcode = PPC::RLDICL; break; + case PPC::SRDo: III.ImmOpcode = PPC::RLDICLo; break; + case PPC::SRAD: III.ImmOpcode = PPC::SRADI; break; + case PPC::SRADo: III.ImmOpcode = PPC::SRADIo; break; + } + break; + // Loads and stores: + case PPC::LBZX: + case PPC::LBZX8: + case PPC::LHZX: + case PPC::LHZX8: + case PPC::LHAX: + case PPC::LHAX8: + case PPC::LWZX: + case PPC::LWZX8: + case PPC::LWAX: + case PPC::LDX: + case PPC::LFSX: + case PPC::LFDX: + case PPC::STBX: + case PPC::STBX8: + case PPC::STHX: + case PPC::STHX8: + case PPC::STWX: + case PPC::STWX8: + case PPC::STDX: + case PPC::STFSX: + case PPC::STFDX: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 1; + III.ZeroIsSpecialNew = 2; + III.IsCommutative = true; + III.ImmOpNo = 1; + III.ConstantOpNo = 2; + switch(Opc) { + default: llvm_unreachable("Unknown opcode"); + case PPC::LBZX: III.ImmOpcode = PPC::LBZ; break; + case PPC::LBZX8: III.ImmOpcode = PPC::LBZ8; break; + case PPC::LHZX: III.ImmOpcode = PPC::LHZ; break; + case PPC::LHZX8: III.ImmOpcode = PPC::LHZ8; break; + case PPC::LHAX: III.ImmOpcode = PPC::LHA; break; + case PPC::LHAX8: III.ImmOpcode = PPC::LHA8; break; + case PPC::LWZX: III.ImmOpcode = PPC::LWZ; break; + case PPC::LWZX8: III.ImmOpcode = PPC::LWZ8; break; + case PPC::LWAX: + III.ImmOpcode = PPC::LWA; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::LDX: III.ImmOpcode = PPC::LD; III.ImmMustBeMultipleOf = 4; break; + case PPC::LFSX: III.ImmOpcode = PPC::LFS; break; + case PPC::LFDX: III.ImmOpcode = PPC::LFD; break; + case PPC::STBX: III.ImmOpcode = PPC::STB; break; + case PPC::STBX8: III.ImmOpcode = PPC::STB8; break; + case PPC::STHX: III.ImmOpcode = PPC::STH; break; + case PPC::STHX8: III.ImmOpcode = PPC::STH8; break; + case PPC::STWX: III.ImmOpcode = PPC::STW; break; + case PPC::STWX8: III.ImmOpcode = PPC::STW8; break; + case PPC::STDX: + III.ImmOpcode = PPC::STD; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::STFSX: III.ImmOpcode = PPC::STFS; break; + case PPC::STFDX: III.ImmOpcode = PPC::STFD; break; + } + break; + case PPC::LBZUX: + case PPC::LBZUX8: + case PPC::LHZUX: + case PPC::LHZUX8: + case PPC::LHAUX: + case PPC::LHAUX8: + case PPC::LWZUX: + case PPC::LWZUX8: + case PPC::LDUX: + case PPC::LFSUX: + case PPC::LFDUX: + case PPC::STBUX: + case PPC::STBUX8: + case PPC::STHUX: + case PPC::STHUX8: + case PPC::STWUX: + case PPC::STWUX8: + case PPC::STDUX: + case PPC::STFSUX: + case PPC::STFDUX: + III.SignedImm = true; + III.ZeroIsSpecialOrig = 2; + III.ZeroIsSpecialNew = 3; + III.IsCommutative = false; + III.ImmOpNo = 2; + III.ConstantOpNo = 3; + switch(Opc) { + default: llvm_unreachable("Unknown opcode"); + case PPC::LBZUX: III.ImmOpcode = PPC::LBZU; break; + case PPC::LBZUX8: III.ImmOpcode = PPC::LBZU8; break; + case PPC::LHZUX: III.ImmOpcode = PPC::LHZU; break; + case PPC::LHZUX8: III.ImmOpcode = PPC::LHZU8; break; + case PPC::LHAUX: III.ImmOpcode = PPC::LHAU; break; + case PPC::LHAUX8: III.ImmOpcode = PPC::LHAU8; break; + case PPC::LWZUX: III.ImmOpcode = PPC::LWZU; break; + case PPC::LWZUX8: III.ImmOpcode = PPC::LWZU8; break; + case PPC::LDUX: + III.ImmOpcode = PPC::LDU; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::LFSUX: III.ImmOpcode = PPC::LFSU; break; + case PPC::LFDUX: III.ImmOpcode = PPC::LFDU; break; + case PPC::STBUX: III.ImmOpcode = PPC::STBU; break; + case PPC::STBUX8: III.ImmOpcode = PPC::STBU8; break; + case PPC::STHUX: III.ImmOpcode = PPC::STHU; break; + case PPC::STHUX8: III.ImmOpcode = PPC::STHU8; break; + case PPC::STWUX: III.ImmOpcode = PPC::STWU; break; + case PPC::STWUX8: III.ImmOpcode = PPC::STWU8; break; + case PPC::STDUX: + III.ImmOpcode = PPC::STDU; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::STFSUX: III.ImmOpcode = PPC::STFSU; break; + case PPC::STFDUX: III.ImmOpcode = PPC::STFDU; break; + } + break; + // Power9 only. + case PPC::LXVX: + case PPC::LXSSPX: + case PPC::LXSDX: + case PPC::STXVX: + case PPC::STXSSPX: + case PPC::STXSDX: + if (!Subtarget.hasP9Vector()) + return false; + III.SignedImm = true; + III.ZeroIsSpecialOrig = 1; + III.ZeroIsSpecialNew = 2; + III.IsCommutative = true; + III.ImmOpNo = 1; + III.ConstantOpNo = 2; + switch(Opc) { + default: llvm_unreachable("Unknown opcode"); + case PPC::LXVX: + III.ImmOpcode = PPC::LXV; + III.ImmMustBeMultipleOf = 16; + break; + case PPC::LXSSPX: + III.ImmOpcode = PPC::LXSSP; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::LXSDX: + III.ImmOpcode = PPC::LXSD; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::STXVX: + III.ImmOpcode = PPC::STXV; + III.ImmMustBeMultipleOf = 16; + break; + case PPC::STXSSPX: + III.ImmOpcode = PPC::STXSSP; + III.ImmMustBeMultipleOf = 4; + break; + case PPC::STXSDX: + III.ImmOpcode = PPC::STXSD; + III.ImmMustBeMultipleOf = 4; + break; + } + break; + } + return true; +} + +// Utility function for swaping two arbitrary operands of an instruction. +static void swapMIOperands(MachineInstr &MI, unsigned Op1, unsigned Op2) { + assert(Op1 != Op2 && "Cannot swap operand with itself."); + + unsigned MaxOp = std::max(Op1, Op2); + unsigned MinOp = std::min(Op1, Op2); + MachineOperand MOp1 = MI.getOperand(MinOp); + MachineOperand MOp2 = MI.getOperand(MaxOp); + MI.RemoveOperand(std::max(Op1, Op2)); + MI.RemoveOperand(std::min(Op1, Op2)); + + // If the operands we are swapping are the two at the end (the common case) + // we can just remove both and add them in the opposite order. + if (MaxOp - MinOp == 1 && MI.getNumOperands() == MinOp) { + MI.addOperand(MOp2); + MI.addOperand(MOp1); + } else { + // Store all operands in a temporary vector, remove them and re-add in the + // right order. + SmallVector<MachineOperand, 2> MOps; + unsigned TotalOps = MI.getNumOperands() + 2; // We've already removed 2 ops. + for (unsigned i = MI.getNumOperands() - 1; i >= MinOp; i--) { + MOps.push_back(MI.getOperand(i)); + MI.RemoveOperand(i); + } + // MOp2 needs to be added next. + MI.addOperand(MOp2); + // Now add the rest. + for (unsigned i = MI.getNumOperands(); i < TotalOps; i++) { + if (i == MaxOp) + MI.addOperand(MOp1); + else { + MI.addOperand(MOps.back()); + MOps.pop_back(); + } + } + } +} + +bool PPCInstrInfo::transformToImmForm(MachineInstr &MI, const ImmInstrInfo &III, + unsigned ConstantOpNo, + int64_t Imm) const { + MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo(); + bool PostRA = !MRI.isSSA(); + // Exit early if we can't convert this. + if ((ConstantOpNo != III.ConstantOpNo) && !III.IsCommutative) + return false; + if (Imm % III.ImmMustBeMultipleOf) + return false; + if (III.SignedImm) { + APInt ActualValue(64, Imm, true); + if (!ActualValue.isSignedIntN(III.ImmWidth)) + return false; + } else { + uint64_t UnsignedMax = (1 << III.ImmWidth) - 1; + if ((uint64_t)Imm > UnsignedMax) + return false; + } + + // If we're post-RA, the instructions don't agree on whether register zero is + // special, we can transform this as long as the register operand that will + // end up in the location where zero is special isn't R0. + if (PostRA && III.ZeroIsSpecialOrig != III.ZeroIsSpecialNew) { + unsigned PosForOrigZero = III.ZeroIsSpecialOrig ? III.ZeroIsSpecialOrig : + III.ZeroIsSpecialNew + 1; + unsigned OrigZeroReg = MI.getOperand(PosForOrigZero).getReg(); + unsigned NewZeroReg = MI.getOperand(III.ZeroIsSpecialNew).getReg(); + // If R0 is in the operand where zero is special for the new instruction, + // it is unsafe to transform if the constant operand isn't that operand. + if ((NewZeroReg == PPC::R0 || NewZeroReg == PPC::X0) && + ConstantOpNo != III.ZeroIsSpecialNew) + return false; + if ((OrigZeroReg == PPC::R0 || OrigZeroReg == PPC::X0) && + ConstantOpNo != PosForOrigZero) + return false; + } + + unsigned Opc = MI.getOpcode(); + bool SpecialShift32 = + Opc == PPC::SLW || Opc == PPC::SLWo || Opc == PPC::SRW || Opc == PPC::SRWo; + bool SpecialShift64 = + Opc == PPC::SLD || Opc == PPC::SLDo || Opc == PPC::SRD || Opc == PPC::SRDo; + bool SetCR = Opc == PPC::SLWo || Opc == PPC::SRWo || + Opc == PPC::SLDo || Opc == PPC::SRDo; + bool RightShift = + Opc == PPC::SRW || Opc == PPC::SRWo || Opc == PPC::SRD || Opc == PPC::SRDo; + + MI.setDesc(get(III.ImmOpcode)); + if (ConstantOpNo == III.ConstantOpNo) { + // Converting shifts to immediate form is a bit tricky since they may do + // one of three things: + // 1. If the shift amount is between OpSize and 2*OpSize, the result is zero + // 2. If the shift amount is zero, the result is unchanged (save for maybe + // setting CR0) + // 3. If the shift amount is in [1, OpSize), it's just a shift + if (SpecialShift32 || SpecialShift64) { + LoadImmediateInfo LII; + LII.Imm = 0; + LII.SetCR = SetCR; + LII.Is64Bit = SpecialShift64; + uint64_t ShAmt = Imm & (SpecialShift32 ? 0x1F : 0x3F); + if (Imm & (SpecialShift32 ? 0x20 : 0x40)) + replaceInstrWithLI(MI, LII); + // Shifts by zero don't change the value. If we don't need to set CR0, + // just convert this to a COPY. Can't do this post-RA since we've already + // cleaned up the copies. + else if (!SetCR && ShAmt == 0 && !PostRA) { + MI.RemoveOperand(2); + MI.setDesc(get(PPC::COPY)); + } else { + // The 32 bit and 64 bit instructions are quite different. + if (SpecialShift32) { + // Left shifts use (N, 0, 31-N), right shifts use (32-N, N, 31). + uint64_t SH = RightShift ? 32 - ShAmt : ShAmt; + uint64_t MB = RightShift ? ShAmt : 0; + uint64_t ME = RightShift ? 31 : 31 - ShAmt; + MI.getOperand(III.ConstantOpNo).ChangeToImmediate(SH); + MachineInstrBuilder(*MI.getParent()->getParent(), MI).addImm(MB) + .addImm(ME); + } else { + // Left shifts use (N, 63-N), right shifts use (64-N, N). + uint64_t SH = RightShift ? 64 - ShAmt : ShAmt; + uint64_t ME = RightShift ? ShAmt : 63 - ShAmt; + MI.getOperand(III.ConstantOpNo).ChangeToImmediate(SH); + MachineInstrBuilder(*MI.getParent()->getParent(), MI).addImm(ME); + } + } + } else + MI.getOperand(ConstantOpNo).ChangeToImmediate(Imm); + } + // Convert commutative instructions (switch the operands and convert the + // desired one to an immediate. + else if (III.IsCommutative) { + MI.getOperand(ConstantOpNo).ChangeToImmediate(Imm); + swapMIOperands(MI, ConstantOpNo, III.ConstantOpNo); + } else + llvm_unreachable("Should have exited early!"); + + // For instructions for which the constant register replaces a different + // operand than where the immediate goes, we need to swap them. + if (III.ConstantOpNo != III.ImmOpNo) + swapMIOperands(MI, III.ConstantOpNo, III.ImmOpNo); + + // If the R0/X0 register is special for the original instruction and not for + // the new instruction (or vice versa), we need to fix up the register class. + if (!PostRA && III.ZeroIsSpecialOrig != III.ZeroIsSpecialNew) { + if (!III.ZeroIsSpecialOrig) { + unsigned RegToModify = MI.getOperand(III.ZeroIsSpecialNew).getReg(); + const TargetRegisterClass *NewRC = + MRI.getRegClass(RegToModify)->hasSuperClassEq(&PPC::GPRCRegClass) ? + &PPC::GPRC_and_GPRC_NOR0RegClass : &PPC::G8RC_and_G8RC_NOX0RegClass; + MRI.setRegClass(RegToModify, NewRC); + } + } + return true; +} + const TargetRegisterClass * PPCInstrInfo::updatedRC(const TargetRegisterClass *RC) const { if (Subtarget.hasVSX() && RC == &PPC::VRRCRegClass) |