[llvm] r214669 - MachineCombiner Pass for selecting faster instruction

Gerolf Hoflehner ghoflehner at apple.com
Mon Aug 4 14:29:22 PDT 2014


Hi Kevin 

thanks for taking care of this. The fails are puzzling to me since they do not reproduce on my machine.

Gerolf
On Aug 3, 2014, at 10:21 PM, Kevin Qin <kevinqindev at gmail.com> wrote:

> Hi Gerolf,
> 
> Because it broke the "make check" for 7 hours, so I get it reverted at r214697. Please fix regressions and commit again.
> 
> 
> Thanks,
> Kevin
> 
> 
> 2014-08-04 11:28 GMT+08:00 Kevin Qin <kevinqindev at gmail.com>:
> Hi Gerolf,
> 
> This commit got make check failed for several  hours,  would you please have a look?
> 
> They are
>     LLVM :: CodeGen/AArch64/arm64-neon-mul-div.ll
>     LLVM :: CodeGen/AArch64/dp-3source.ll
> 
> 
> 
> Thanks,
> Kevin
> 
> 
> 2014-08-04 6:03 GMT+08:00 Gerolf Hoflehner <ghoflehner at apple.com>:
> 
> Author: ghoflehner
> Date: Sun Aug  3 17:03:40 2014
> New Revision: 214669
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=214669&view=rev
> Log:
> MachineCombiner Pass for selecting faster instruction
>  sequence -  AArch64 target support
> 
>  This patch turns off madd/msub generation in the DAGCombiner and generates
>  them in the MachineCombiner instead. It replaces the original code sequence
>  with the combined sequence when it is beneficial to do so.
> 
>  When there is no machine model support it always generates the madd/msub
>  instruction. This is true also when the objective is to optimize for code
>  size: when the combined sequence is shorter is always chosen and does not
>  get evaluated.
> 
>  When there is a machine model the combined instruction sequence
>  is evaluated for critical path and resource length using machine
>  trace metrics and the original code sequence is replaced when it is
>  determined to be faster.
> 
>  rdar://16319955
> 
> 
> Added:
>     llvm/trunk/lib/Target/AArch64/AArch64MachineCombinerPattern.h
>     llvm/trunk/test/CodeGen/AArch64/madd-lohi.ll
> Modified:
>     llvm/trunk/lib/Target/AArch64/AArch64InstrFormats.td
>     llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.cpp
>     llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.h
>     llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp
>     llvm/trunk/test/CodeGen/AArch64/arm64-neon-mul-div.ll
>     llvm/trunk/test/CodeGen/AArch64/dp-3source.ll
>     llvm/trunk/test/CodeGen/AArch64/mul-lohi.ll
> 
> Modified: llvm/trunk/lib/Target/AArch64/AArch64InstrFormats.td
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64InstrFormats.td?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/AArch64/AArch64InstrFormats.td (original)
> +++ llvm/trunk/lib/Target/AArch64/AArch64InstrFormats.td Sun Aug  3 17:03:40 2014
> @@ -1351,14 +1351,15 @@ class BaseMulAccum<bit isSub, bits<3> op
>  }
> 
>  multiclass MulAccum<bit isSub, string asm, SDNode AccNode> {
> +  // MADD/MSUB generation is decided by MachineCombiner.cpp
>    def Wrrr : BaseMulAccum<isSub, 0b000, GPR32, GPR32, asm,
> -      [(set GPR32:$Rd, (AccNode GPR32:$Ra, (mul GPR32:$Rn, GPR32:$Rm)))]>,
> +      [/*(set GPR32:$Rd, (AccNode GPR32:$Ra, (mul GPR32:$Rn, GPR32:$Rm)))*/]>,
>        Sched<[WriteIM32, ReadIM, ReadIM, ReadIMA]> {
>      let Inst{31} = 0;
>    }
> 
>    def Xrrr : BaseMulAccum<isSub, 0b000, GPR64, GPR64, asm,
> -      [(set GPR64:$Rd, (AccNode GPR64:$Ra, (mul GPR64:$Rn, GPR64:$Rm)))]>,
> +      [/*(set GPR64:$Rd, (AccNode GPR64:$Ra, (mul GPR64:$Rn, GPR64:$Rm)))*/]>,
>        Sched<[WriteIM64, ReadIM, ReadIM, ReadIMA]> {
>      let Inst{31} = 1;
>    }
> 
> Modified: llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.cpp?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.cpp (original)
> +++ llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.cpp Sun Aug  3 17:03:40 2014
> @@ -14,6 +14,7 @@
>  #include "AArch64InstrInfo.h"
>  #include "AArch64Subtarget.h"
>  #include "MCTargetDesc/AArch64AddressingModes.h"
> +#include "AArch64MachineCombinerPattern.h"
>  #include "llvm/CodeGen/MachineFrameInfo.h"
>  #include "llvm/CodeGen/MachineInstrBuilder.h"
>  #include "llvm/CodeGen/MachineMemOperand.h"
> @@ -697,17 +698,12 @@ static bool UpdateOperandRegClass(Machin
>    return true;
>  }
> 
> -/// optimizeCompareInstr - Convert the instruction supplying the argument to the
> -/// comparison into one that sets the zero bit in the flags register.
> -bool AArch64InstrInfo::optimizeCompareInstr(
> -    MachineInstr *CmpInstr, unsigned SrcReg, unsigned SrcReg2, int CmpMask,
> -    int CmpValue, const MachineRegisterInfo *MRI) const {
> -
> -  // Replace SUBSWrr with SUBWrr if NZCV is not used.
> -  int Cmp_NZCV = CmpInstr->findRegisterDefOperandIdx(AArch64::NZCV, true);
> -  if (Cmp_NZCV != -1) {
> +/// convertFlagSettingOpcode - return opcode that does not
> +/// set flags when possible. The caller is responsible to do
> +/// the actual substitution and legality checking.
> +static unsigned convertFlagSettingOpcode(MachineInstr *MI) {
>      unsigned NewOpc;
> -    switch (CmpInstr->getOpcode()) {
> +    switch (MI->getOpcode()) {
>      default:
>        return false;
>      case AArch64::ADDSWrr:      NewOpc = AArch64::ADDWrr; break;
> @@ -727,7 +723,22 @@ bool AArch64InstrInfo::optimizeCompareIn
>      case AArch64::SUBSXrs:      NewOpc = AArch64::SUBXrs; break;
>      case AArch64::SUBSXrx:      NewOpc = AArch64::SUBXrx; break;
>      }
> +    return NewOpc;
> +}
> 
> +/// optimizeCompareInstr - Convert the instruction supplying the argument to the
> +/// comparison into one that sets the zero bit in the flags register.
> +bool AArch64InstrInfo::optimizeCompareInstr(
> +    MachineInstr *CmpInstr, unsigned SrcReg, unsigned SrcReg2, int CmpMask,
> +    int CmpValue, const MachineRegisterInfo *MRI) const {
> +
> +  // Replace SUBSWrr with SUBWrr if NZCV is not used.
> +  int Cmp_NZCV = CmpInstr->findRegisterDefOperandIdx(AArch64::NZCV, true);
> +  if (Cmp_NZCV != -1) {
> +    unsigned Opc = CmpInstr->getOpcode();
> +    unsigned NewOpc = convertFlagSettingOpcode(CmpInstr);
> +    if (NewOpc == Opc)
> +      return false;
>      const MCInstrDesc &MCID = get(NewOpc);
>      CmpInstr->setDesc(MCID);
>      CmpInstr->RemoveOperand(Cmp_NZCV);
> @@ -2185,3 +2196,448 @@ void AArch64InstrInfo::getNoopForMachoTa
>    NopInst.setOpcode(AArch64::HINT);
>    NopInst.addOperand(MCOperand::CreateImm(0));
>  }
> +/// useMachineCombiner - return true when a target supports MachineCombiner
> +bool AArch64InstrInfo::useMachineCombiner(void) const {
> +  // AArch64 supports the combiner
> +  return true;
> +}
> +//
> +// True when Opc sets flag
> +static bool isCombineInstrSettingFlag(unsigned Opc) {
> +  switch (Opc) {
> +  case AArch64::ADDSWrr:
> +  case AArch64::ADDSWri:
> +  case AArch64::ADDSXrr:
> +  case AArch64::ADDSXri:
> +  case AArch64::SUBSWrr:
> +  case AArch64::SUBSXrr:
> +  // Note: MSUB Wd,Wn,Wm,Wi -> Wd = Wi - WnxWm, not Wd=WnxWm - Wi.
> +  case AArch64::SUBSWri:
> +  case AArch64::SUBSXri:
> +    return true;
> +  default:
> +    break;
> +  }
> +  return false;
> +}
> +//
> +// 32b Opcodes that can be combined with a MUL
> +static bool isCombineInstrCandidate32(unsigned Opc) {
> +  switch (Opc) {
> +  case AArch64::ADDWrr:
> +  case AArch64::ADDWri:
> +  case AArch64::SUBWrr:
> +  case AArch64::ADDSWrr:
> +  case AArch64::ADDSWri:
> +  case AArch64::SUBSWrr:
> +  // Note: MSUB Wd,Wn,Wm,Wi -> Wd = Wi - WnxWm, not Wd=WnxWm - Wi.
> +  case AArch64::SUBWri:
> +  case AArch64::SUBSWri:
> +    return true;
> +  default:
> +    break;
> +  }
> +  return false;
> +}
> +//
> +// 64b Opcodes that can be combined with a MUL
> +static bool isCombineInstrCandidate64(unsigned Opc) {
> +  switch (Opc) {
> +  case AArch64::ADDXrr:
> +  case AArch64::ADDXri:
> +  case AArch64::SUBXrr:
> +  case AArch64::ADDSXrr:
> +  case AArch64::ADDSXri:
> +  case AArch64::SUBSXrr:
> +  // Note: MSUB Wd,Wn,Wm,Wi -> Wd = Wi - WnxWm, not Wd=WnxWm - Wi.
> +  case AArch64::SUBXri:
> +  case AArch64::SUBSXri:
> +    return true;
> +  default:
> +    break;
> +  }
> +  return false;
> +}
> +//
> +// Opcodes that can be combined with a MUL
> +static bool isCombineInstrCandidate(unsigned Opc) {
> +  return (isCombineInstrCandidate32(Opc) || isCombineInstrCandidate64(Opc));
> +}
> +
> +static bool canCombineWithMUL(MachineBasicBlock &MBB, MachineOperand &MO,
> +                              unsigned MulOpc, unsigned ZeroReg) {
> +  MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
> +  MachineInstr *MI = nullptr;
> +  // We need a virtual register definition.
> +  if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()))
> +    MI = MRI.getUniqueVRegDef(MO.getReg());
> +  // And it needs to be in the trace (otherwise, it won't have a depth).
> +  if (!MI || MI->getParent() != &MBB || (unsigned)MI->getOpcode() != MulOpc)
> +    return false;
> +
> +  assert(MI->getNumOperands() >= 4 && MI->getOperand(0).isReg() &&
> +         MI->getOperand(1).isReg() && MI->getOperand(2).isReg() &&
> +         MI->getOperand(3).isReg() && "MAdd/MSub must have a least 4 regs");
> +
> +  // The third input reg must be zero.
> +  if (MI->getOperand(3).getReg() != ZeroReg)
> +    return false;
> +
> +  // Must only used by the user we combine with.
> +  if (!MRI.hasOneNonDBGUse(MI->getOperand(0).getReg()))
> +    return false;
> +
> +  return true;
> +}
> +
> +/// hasPattern - return true when there is potentially a faster code sequence
> +/// for an instruction chain ending in \p Root. All potential patterns are
> +/// listed
> +/// in the \p Pattern vector. Pattern should be sorted in priority order since
> +/// the pattern evaluator stops checking as soon as it finds a faster sequence.
> +
> +bool AArch64InstrInfo::hasPattern(
> +    MachineInstr &Root,
> +    SmallVectorImpl<MachineCombinerPattern::MC_PATTERN> &Pattern) const {
> +  unsigned Opc = Root.getOpcode();
> +  MachineBasicBlock &MBB = *Root.getParent();
> +  bool Found = false;
> +
> +  if (!isCombineInstrCandidate(Opc))
> +    return 0;
> +  if (isCombineInstrSettingFlag(Opc)) {
> +    int Cmp_NZCV = Root.findRegisterDefOperandIdx(AArch64::NZCV, true);
> +    // When NZCV is live bail out.
> +    if (Cmp_NZCV == -1)
> +      return 0;
> +    unsigned NewOpc = convertFlagSettingOpcode(&Root);
> +    // When opcode can't change bail out.
> +    // CHECKME: do we miss any cases for opcode conversion?
> +    if (NewOpc == Opc)
> +      return 0;
> +    Opc = NewOpc;
> +  }
> +
> +  switch (Opc) {
> +  default:
> +    break;
> +  case AArch64::ADDWrr:
> +    assert(Root.getOperand(1).isReg() && Root.getOperand(2).isReg() &&
> +           "ADDWrr does not have register operands");
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
> +                          AArch64::WZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULADDW_OP1);
> +      Found = true;
> +    }
> +    if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDWrrr,
> +                          AArch64::WZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULADDW_OP2);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::ADDXrr:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
> +                          AArch64::XZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULADDX_OP1);
> +      Found = true;
> +    }
> +    if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDXrrr,
> +                          AArch64::XZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULADDX_OP2);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::SUBWrr:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
> +                          AArch64::WZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULSUBW_OP1);
> +      Found = true;
> +    }
> +    if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDWrrr,
> +                          AArch64::WZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULSUBW_OP2);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::SUBXrr:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
> +                          AArch64::XZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULSUBX_OP1);
> +      Found = true;
> +    }
> +    if (canCombineWithMUL(MBB, Root.getOperand(2), AArch64::MADDXrrr,
> +                          AArch64::XZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULSUBX_OP2);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::ADDWri:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
> +                          AArch64::WZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULADDWI_OP1);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::ADDXri:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
> +                          AArch64::XZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULADDXI_OP1);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::SUBWri:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDWrrr,
> +                          AArch64::WZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULSUBWI_OP1);
> +      Found = true;
> +    }
> +    break;
> +  case AArch64::SUBXri:
> +    if (canCombineWithMUL(MBB, Root.getOperand(1), AArch64::MADDXrrr,
> +                          AArch64::XZR)) {
> +      Pattern.push_back(MachineCombinerPattern::MC_MULSUBXI_OP1);
> +      Found = true;
> +    }
> +    break;
> +  }
> +  return Found;
> +}
> +
> +/// genMadd - Generate madd instruction and combine mul and add.
> +/// Example:
> +///  MUL I=A,B,0
> +///  ADD R,I,C
> +///  ==> MADD R,A,B,C
> +/// \param Root is the ADD instruction
> +/// \param [out] InsInstr is a vector of machine instructions and will
> +/// contain the generated madd instruction
> +/// \param IdxMulOpd is index of operand in Root that is the result of
> +/// the MUL. In the example above IdxMulOpd is 1.
> +/// \param MaddOpc the opcode fo the madd instruction
> +static MachineInstr *genMadd(MachineFunction &MF, MachineRegisterInfo &MRI,
> +                             const TargetInstrInfo *TII, MachineInstr &Root,
> +                             SmallVectorImpl<MachineInstr *> &InsInstrs,
> +                             unsigned IdxMulOpd, unsigned MaddOpc) {
> +  assert(IdxMulOpd == 1 || IdxMulOpd == 2);
> +
> +  unsigned IdxOtherOpd = IdxMulOpd == 1 ? 2 : 1;
> +  MachineInstr *MUL = MRI.getUniqueVRegDef(Root.getOperand(IdxMulOpd).getReg());
> +  MachineOperand R = Root.getOperand(0);
> +  MachineOperand A = MUL->getOperand(1);
> +  MachineOperand B = MUL->getOperand(2);
> +  MachineOperand C = Root.getOperand(IdxOtherOpd);
> +  MachineInstrBuilder MIB = BuildMI(MF, Root.getDebugLoc(), TII->get(MaddOpc))
> +                                .addOperand(R)
> +                                .addOperand(A)
> +                                .addOperand(B)
> +                                .addOperand(C);
> +  // Insert the MADD
> +  InsInstrs.push_back(MIB);
> +  return MUL;
> +}
> +
> +/// genMaddR - Generate madd instruction and combine mul and add using
> +/// an extra virtual register
> +/// Example - an ADD intermediate needs to be stored in a register:
> +///   MUL I=A,B,0
> +///   ADD R,I,Imm
> +///   ==> ORR  V, ZR, Imm
> +///   ==> MADD R,A,B,V
> +/// \param Root is the ADD instruction
> +/// \param [out] InsInstr is a vector of machine instructions and will
> +/// contain the generated madd instruction
> +/// \param IdxMulOpd is index of operand in Root that is the result of
> +/// the MUL. In the example above IdxMulOpd is 1.
> +/// \param MaddOpc the opcode fo the madd instruction
> +/// \param VR is a virtual register that holds the value of an ADD operand
> +/// (V in the example above).
> +static MachineInstr *genMaddR(MachineFunction &MF, MachineRegisterInfo &MRI,
> +                              const TargetInstrInfo *TII, MachineInstr &Root,
> +                              SmallVectorImpl<MachineInstr *> &InsInstrs,
> +                              unsigned IdxMulOpd, unsigned MaddOpc,
> +                              unsigned VR) {
> +  assert(IdxMulOpd == 1 || IdxMulOpd == 2);
> +
> +  MachineInstr *MUL = MRI.getUniqueVRegDef(Root.getOperand(IdxMulOpd).getReg());
> +  MachineOperand R = Root.getOperand(0);
> +  MachineOperand A = MUL->getOperand(1);
> +  MachineOperand B = MUL->getOperand(2);
> +  MachineInstrBuilder MIB = BuildMI(MF, Root.getDebugLoc(), TII->get(MaddOpc))
> +                                .addOperand(R)
> +                                .addOperand(A)
> +                                .addOperand(B)
> +                                .addReg(VR);
> +  // Insert the MADD
> +  InsInstrs.push_back(MIB);
> +  return MUL;
> +}
> +/// genAlternativeCodeSequence - when hasPattern() finds a pattern
> +/// this function generates the instructions that could replace the
> +/// original code sequence
> +void AArch64InstrInfo::genAlternativeCodeSequence(
> +    MachineInstr &Root, MachineCombinerPattern::MC_PATTERN Pattern,
> +    SmallVectorImpl<MachineInstr *> &InsInstrs,
> +    SmallVectorImpl<MachineInstr *> &DelInstrs,
> +    DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const {
> +  MachineBasicBlock &MBB = *Root.getParent();
> +  MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
> +  MachineFunction &MF = *MBB.getParent();
> +  const TargetInstrInfo *TII = MF.getTarget().getInstrInfo();
> +
> +  MachineInstr *MUL;
> +  unsigned Opc;
> +  switch (Pattern) {
> +  default:
> +    // signal error.
> +    break;
> +  case MachineCombinerPattern::MC_MULADDW_OP1:
> +  case MachineCombinerPattern::MC_MULADDX_OP1:
> +    // MUL I=A,B,0
> +    // ADD R,I,C
> +    // ==> MADD R,A,B,C
> +    // --- Create(MADD);
> +    Opc = Pattern == MachineCombinerPattern::MC_MULADDW_OP1 ? AArch64::MADDWrrr
> +                                                            : AArch64::MADDXrrr;
> +    MUL = genMadd(MF, MRI, TII, Root, InsInstrs, 1, Opc);
> +    break;
> +  case MachineCombinerPattern::MC_MULADDW_OP2:
> +  case MachineCombinerPattern::MC_MULADDX_OP2:
> +    // MUL I=A,B,0
> +    // ADD R,C,I
> +    // ==> MADD R,A,B,C
> +    // --- Create(MADD);
> +    Opc = Pattern == MachineCombinerPattern::MC_MULADDW_OP2 ? AArch64::MADDWrrr
> +                                                            : AArch64::MADDXrrr;
> +    MUL = genMadd(MF, MRI, TII, Root, InsInstrs, 2, Opc);
> +    break;
> +  case MachineCombinerPattern::MC_MULADDWI_OP1:
> +  case MachineCombinerPattern::MC_MULADDXI_OP1:
> +    // MUL I=A,B,0
> +    // ADD R,I,Imm
> +    // ==> ORR  V, ZR, Imm
> +    // ==> MADD R,A,B,V
> +    // --- Create(MADD);
> +    {
> +      const TargetRegisterClass *RC =
> +          MRI.getRegClass(Root.getOperand(1).getReg());
> +      unsigned NewVR = MRI.createVirtualRegister(RC);
> +      unsigned BitSize, OrrOpc, ZeroReg;
> +      if (Pattern == MachineCombinerPattern::MC_MULADDWI_OP1) {
> +        BitSize = 32;
> +        OrrOpc = AArch64::ORRWri;
> +        ZeroReg = AArch64::WZR;
> +        Opc = AArch64::MADDWrrr;
> +      } else {
> +        OrrOpc = AArch64::ORRXri;
> +        BitSize = 64;
> +        ZeroReg = AArch64::XZR;
> +        Opc = AArch64::MADDXrrr;
> +      }
> +      uint64_t Imm = Root.getOperand(2).getImm();
> +
> +      if (Root.getOperand(3).isImm()) {
> +        unsigned val = Root.getOperand(3).getImm();
> +        Imm = Imm << val;
> +      }
> +      uint64_t UImm = Imm << (64 - BitSize) >> (64 - BitSize);
> +      uint64_t Encoding;
> +
> +      if (AArch64_AM::processLogicalImmediate(UImm, BitSize, Encoding)) {
> +        MachineInstrBuilder MIB1 =
> +            BuildMI(MF, Root.getDebugLoc(), TII->get(OrrOpc))
> +                .addOperand(MachineOperand::CreateReg(NewVR, RegState::Define))
> +                .addReg(ZeroReg)
> +                .addImm(Encoding);
> +        InsInstrs.push_back(MIB1);
> +        InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
> +        MUL = genMaddR(MF, MRI, TII, Root, InsInstrs, 1, Opc, NewVR);
> +      }
> +    }
> +    break;
> +  case MachineCombinerPattern::MC_MULSUBW_OP1:
> +  case MachineCombinerPattern::MC_MULSUBX_OP1: {
> +    // MUL I=A,B,0
> +    // SUB R,I, C
> +    // ==> SUB  V, 0, C
> +    // ==> MADD R,A,B,V // = -C + A*B
> +    // --- Create(MADD);
> +    const TargetRegisterClass *RC =
> +        MRI.getRegClass(Root.getOperand(1).getReg());
> +    unsigned NewVR = MRI.createVirtualRegister(RC);
> +    unsigned SubOpc, ZeroReg;
> +    if (Pattern == MachineCombinerPattern::MC_MULSUBW_OP1) {
> +      SubOpc = AArch64::SUBWrr;
> +      ZeroReg = AArch64::WZR;
> +      Opc = AArch64::MADDWrrr;
> +    } else {
> +      SubOpc = AArch64::SUBXrr;
> +      ZeroReg = AArch64::XZR;
> +      Opc = AArch64::MADDXrrr;
> +    }
> +    // SUB NewVR, 0, C
> +    MachineInstrBuilder MIB1 =
> +        BuildMI(MF, Root.getDebugLoc(), TII->get(SubOpc))
> +            .addOperand(MachineOperand::CreateReg(NewVR, RegState::Define))
> +            .addReg(ZeroReg)
> +            .addOperand(Root.getOperand(2));
> +    InsInstrs.push_back(MIB1);
> +    InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
> +    MUL = genMaddR(MF, MRI, TII, Root, InsInstrs, 1, Opc, NewVR);
> +  } break;
> +  case MachineCombinerPattern::MC_MULSUBW_OP2:
> +  case MachineCombinerPattern::MC_MULSUBX_OP2:
> +    // MUL I=A,B,0
> +    // SUB R,C,I
> +    // ==> MSUB R,A,B,C (computes C - A*B)
> +    // --- Create(MSUB);
> +    Opc = Pattern == MachineCombinerPattern::MC_MULSUBW_OP2 ? AArch64::MSUBWrrr
> +                                                            : AArch64::MSUBXrrr;
> +    MUL = genMadd(MF, MRI, TII, Root, InsInstrs, 2, Opc);
> +    break;
> +  case MachineCombinerPattern::MC_MULSUBWI_OP1:
> +  case MachineCombinerPattern::MC_MULSUBXI_OP1: {
> +    // MUL I=A,B,0
> +    // SUB R,I, Imm
> +    // ==> ORR  V, ZR, -Imm
> +    // ==> MADD R,A,B,V // = -Imm + A*B
> +    // --- Create(MADD);
> +    const TargetRegisterClass *RC =
> +        MRI.getRegClass(Root.getOperand(1).getReg());
> +    unsigned NewVR = MRI.createVirtualRegister(RC);
> +    unsigned BitSize, OrrOpc, ZeroReg;
> +    if (Pattern == MachineCombinerPattern::MC_MULSUBWI_OP1) {
> +      BitSize = 32;
> +      OrrOpc = AArch64::ORRWri;
> +      ZeroReg = AArch64::WZR;
> +      Opc = AArch64::MADDWrrr;
> +    } else {
> +      OrrOpc = AArch64::ORRXri;
> +      BitSize = 64;
> +      ZeroReg = AArch64::XZR;
> +      Opc = AArch64::MADDXrrr;
> +    }
> +    int Imm = Root.getOperand(2).getImm();
> +    if (Root.getOperand(3).isImm()) {
> +      unsigned val = Root.getOperand(3).getImm();
> +      Imm = Imm << val;
> +    }
> +    uint64_t UImm = -Imm << (64 - BitSize) >> (64 - BitSize);
> +    uint64_t Encoding;
> +    if (AArch64_AM::processLogicalImmediate(UImm, BitSize, Encoding)) {
> +      MachineInstrBuilder MIB1 =
> +          BuildMI(MF, Root.getDebugLoc(), TII->get(OrrOpc))
> +              .addOperand(MachineOperand::CreateReg(NewVR, RegState::Define))
> +              .addReg(ZeroReg)
> +              .addImm(Encoding);
> +      InsInstrs.push_back(MIB1);
> +      InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
> +      MUL = genMaddR(MF, MRI, TII, Root, InsInstrs, 1, Opc, NewVR);
> +    }
> +  } break;
> +  }
> +  // Record MUL and ADD/SUB for deletion
> +  DelInstrs.push_back(MUL);
> +  DelInstrs.push_back(&Root);
> +
> +  return;
> +}
> 
> Modified: llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.h?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.h (original)
> +++ llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.h Sun Aug  3 17:03:40 2014
> @@ -17,6 +17,7 @@
>  #include "AArch64.h"
>  #include "AArch64RegisterInfo.h"
>  #include "llvm/Target/TargetInstrInfo.h"
> +#include "llvm/CodeGen/MachineCombinerPattern.h"
> 
>  #define GET_INSTRINFO_HEADER
>  #include "AArch64GenInstrInfo.inc"
> @@ -156,9 +157,26 @@ public:
>    bool optimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg,
>                              unsigned SrcReg2, int CmpMask, int CmpValue,
>                              const MachineRegisterInfo *MRI) const override;
> +  /// hasPattern - return true when there is potentially a faster code sequence
> +  /// for an instruction chain ending in <Root>. All potential patterns are
> +  /// listed
> +  /// in the <Pattern> array.
> +  virtual bool hasPattern(
> +      MachineInstr &Root,
> +      SmallVectorImpl<MachineCombinerPattern::MC_PATTERN> &Pattern) const;
> +
> +  /// genAlternativeCodeSequence - when hasPattern() finds a pattern
> +  /// this function generates the instructions that could replace the
> +  /// original code sequence
> +  virtual void genAlternativeCodeSequence(
> +      MachineInstr &Root, MachineCombinerPattern::MC_PATTERN P,
> +      SmallVectorImpl<MachineInstr *> &InsInstrs,
> +      SmallVectorImpl<MachineInstr *> &DelInstrs,
> +      DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const;
> +  /// useMachineCombiner - AArch64 supports MachineCombiner
> +  virtual bool useMachineCombiner(void) const;
> 
>    bool expandPostRAPseudo(MachineBasicBlock::iterator MI) const override;
> -
>  private:
>    void instantiateCondBranch(MachineBasicBlock &MBB, DebugLoc DL,
>                               MachineBasicBlock *TBB,
> 
> Added: llvm/trunk/lib/Target/AArch64/AArch64MachineCombinerPattern.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64MachineCombinerPattern.h?rev=214669&view=auto
> ==============================================================================
> --- llvm/trunk/lib/Target/AArch64/AArch64MachineCombinerPattern.h (added)
> +++ llvm/trunk/lib/Target/AArch64/AArch64MachineCombinerPattern.h Sun Aug  3 17:03:40 2014
> @@ -0,0 +1,42 @@
> +//===- AArch64MachineCombinerPattern.h                                    -===//
> +//===- AArch64 instruction pattern supported by combiner                  -===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +//
> +// This file defines instruction pattern supported by combiner
> +//
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLVM_TARGET_AArch64MACHINECOMBINERPATTERN_H
> +#define LLVM_TARGET_AArch64MACHINECOMBINERPATTERN_H
> +
> +namespace llvm {
> +
> +/// Enumeration of instruction pattern supported by machine combiner
> +///
> +///
> +namespace MachineCombinerPattern {
> +enum MC_PATTERN : int {
> +  MC_NONE = 0,
> +  MC_MULADDW_OP1 = 1,
> +  MC_MULADDW_OP2 = 2,
> +  MC_MULSUBW_OP1 = 3,
> +  MC_MULSUBW_OP2 = 4,
> +  MC_MULADDWI_OP1 = 5,
> +  MC_MULSUBWI_OP1 = 6,
> +  MC_MULADDX_OP1 = 7,
> +  MC_MULADDX_OP2 = 8,
> +  MC_MULSUBX_OP1 = 9,
> +  MC_MULSUBX_OP2 = 10,
> +  MC_MULADDXI_OP1 = 11,
> +  MC_MULSUBXI_OP1 = 12
> +};
> +} // end namespace MachineCombinerPattern
> +} // end namespace llvm
> +
> +#endif
> 
> Modified: llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp (original)
> +++ llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp Sun Aug  3 17:03:40 2014
> @@ -24,6 +24,10 @@ static cl::opt<bool>
>  EnableCCMP("aarch64-ccmp", cl::desc("Enable the CCMP formation pass"),
>             cl::init(true), cl::Hidden);
> 
> +static cl::opt<bool> EnableMCR("aarch64-mcr",
> +                               cl::desc("Enable the machine combiner pass"),
> +                               cl::init(true), cl::Hidden);
> +
>  static cl::opt<bool>
>  EnableStPairSuppress("aarch64-stp-suppress", cl::desc("Suppress STP for AArch64"),
>                       cl::init(true), cl::Hidden);
> @@ -174,6 +178,8 @@ bool AArch64PassConfig::addInstSelector(
>  bool AArch64PassConfig::addILPOpts() {
>    if (EnableCCMP)
>      addPass(createAArch64ConditionalCompares());
> +  if (EnableMCR)
> +    addPass(&MachineCombinerID);
>    addPass(&EarlyIfConverterID);
>    if (EnableStPairSuppress)
>      addPass(createAArch64StorePairSuppressPass());
> 
> Modified: llvm/trunk/test/CodeGen/AArch64/arm64-neon-mul-div.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/arm64-neon-mul-div.ll?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AArch64/arm64-neon-mul-div.ll (original)
> +++ llvm/trunk/test/CodeGen/AArch64/arm64-neon-mul-div.ll Sun Aug  3 17:03:40 2014
> @@ -1,4 +1,4 @@
> -; RUN: llc < %s -verify-machineinstrs -mtriple=arm64-none-linux-gnu -mattr=+neon | FileCheck %s
> +; RUN: llc < %s -verify-machineinstrs -mtriple=arm64-none-linux-gnu -mattr=+neon -mcpu=cyclone | FileCheck %s
>  ; arm64 has its own copy of this because of the intrinsics
> 
>  define <8 x i8> @mul8xi8(<8 x i8> %A, <8 x i8> %B) {
> @@ -450,8 +450,8 @@ define <1 x i32> @srem1x32(<1 x i32> %A,
>  define <2 x i32> @srem2x32(<2 x i32> %A, <2 x i32> %B) {
>  ; CHECK-LABEL: srem2x32:
>  ; CHECK: sdiv {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
> -; CHECK: sdiv {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
>  ; CHECK: msub {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
> +; CHECK: sdiv {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
>  ; CHECK: msub {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
>         %tmp3 = srem <2 x i32> %A, %B;
>         ret <2 x i32> %tmp3
> @@ -482,8 +482,8 @@ define <1 x i64> @srem1x64(<1 x i64> %A,
>  define <2 x i64> @srem2x64(<2 x i64> %A, <2 x i64> %B) {
>  ; CHECK-LABEL: srem2x64:
>  ; CHECK: sdiv {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
> -; CHECK: sdiv {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
>  ; CHECK: msub {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
> +; CHECK: sdiv {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
>  ; CHECK: msub {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
>         %tmp3 = srem <2 x i64> %A, %B;
>         ret <2 x i64> %tmp3
> @@ -612,8 +612,8 @@ define <1 x i32> @urem1x32(<1 x i32> %A,
>  define <2 x i32> @urem2x32(<2 x i32> %A, <2 x i32> %B) {
>  ; CHECK-LABEL: urem2x32:
>  ; CHECK: udiv {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
> -; CHECK: udiv {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
>  ; CHECK: msub {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
> +; CHECK: udiv {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
>  ; CHECK: msub {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
>         %tmp3 = urem <2 x i32> %A, %B;
>         ret <2 x i32> %tmp3
> @@ -644,8 +644,8 @@ define <1 x i64> @urem1x64(<1 x i64> %A,
>  define <2 x i64> @urem2x64(<2 x i64> %A, <2 x i64> %B) {
>  ; CHECK-LABEL: urem2x64:
>  ; CHECK: udiv {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
> -; CHECK: udiv {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
>  ; CHECK: msub {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
> +; CHECK: udiv {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
>  ; CHECK: msub {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}, {{x[0-9]+}}
>         %tmp3 = urem <2 x i64> %A, %B;
>         ret <2 x i64> %tmp3
> 
> Modified: llvm/trunk/test/CodeGen/AArch64/dp-3source.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/dp-3source.ll?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AArch64/dp-3source.ll (original)
> +++ llvm/trunk/test/CodeGen/AArch64/dp-3source.ll Sun Aug  3 17:03:40 2014
> @@ -1,4 +1,4 @@
> -; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 | FileCheck %s
> +; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 -mcpu=cyclone | FileCheck %s
> 
>  define i32 @test_madd32(i32 %val0, i32 %val1, i32 %val2) {
>  ; CHECK-LABEL: test_madd32:
> 
> Added: llvm/trunk/test/CodeGen/AArch64/madd-lohi.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/madd-lohi.ll?rev=214669&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AArch64/madd-lohi.ll (added)
> +++ llvm/trunk/test/CodeGen/AArch64/madd-lohi.ll Sun Aug  3 17:03:40 2014
> @@ -0,0 +1,19 @@
> +; RUN: llc -mtriple=arm64-apple-ios7.0 %s -o - | FileCheck %s
> +; RUN: llc -mtriple=aarch64_be-linux-gnu %s -o - | FileCheck --check-prefix=CHECK-BE %s
> +
> +define i128 @test_128bitmul(i128 %lhs, i128 %rhs) {
> +; CHECK-LABEL: test_128bitmul:
> +; CHECK-DAG: umulh [[CARRY:x[0-9]+]], x0, x2
> +; CHECK-DAG: madd [[PART1:x[0-9]+]], x0, x3, [[CARRY]]
> +; CHECK: madd x1, x1, x2, [[PART1]]
> +; CHECK: mul x0, x0, x2
> +
> +; CHECK-BE-LABEL: test_128bitmul:
> +; CHECK-BE-DAG: umulh [[CARRY:x[0-9]+]], x1, x3
> +; CHECK-BE-DAG: madd [[PART1:x[0-9]+]], x1, x2, [[CARRY]]
> +; CHECK-BE: madd x0, x0, x3, [[PART1]]
> +; CHECK-BE: mul x1, x1, x3
> +
> +  %prod = mul i128 %lhs, %rhs
> +  ret i128 %prod
> +}
> 
> Modified: llvm/trunk/test/CodeGen/AArch64/mul-lohi.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/mul-lohi.ll?rev=214669&r1=214668&r2=214669&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AArch64/mul-lohi.ll (original)
> +++ llvm/trunk/test/CodeGen/AArch64/mul-lohi.ll Sun Aug  3 17:03:40 2014
> @@ -1,17 +1,16 @@
> -; RUN: llc -mtriple=arm64-apple-ios7.0 %s -o - | FileCheck %s
> -; RUN: llc -mtriple=aarch64_be-linux-gnu %s -o - | FileCheck --check-prefix=CHECK-BE %s
> -
> +; RUN: llc -mtriple=arm64-apple-ios7.0 -mcpu=cyclone %s -o - | FileCheck %s
> +; RUN: llc -mtriple=aarch64_be-linux-gnu -mcpu=cyclone %s -o - | FileCheck --check-prefix=CHECK-BE %s
>  define i128 @test_128bitmul(i128 %lhs, i128 %rhs) {
>  ; CHECK-LABEL: test_128bitmul:
> +; CHECK-DAG: mul [[PART1:x[0-9]+]], x0, x3
>  ; CHECK-DAG: umulh [[CARRY:x[0-9]+]], x0, x2
> -; CHECK-DAG: madd [[PART1:x[0-9]+]], x0, x3, [[CARRY]]
> -; CHECK: madd x1, x1, x2, [[PART1]]
> +; CHECK: mul [[PART2:x[0-9]+]], x1, x2
>  ; CHECK: mul x0, x0, x2
> 
>  ; CHECK-BE-LABEL: test_128bitmul:
> +; CHECK-BE-DAG: mul [[PART1:x[0-9]+]], x1, x2
>  ; CHECK-BE-DAG: umulh [[CARRY:x[0-9]+]], x1, x3
> -; CHECK-BE-DAG: madd [[PART1:x[0-9]+]], x1, x2, [[CARRY]]
> -; CHECK-BE: madd x0, x0, x3, [[PART1]]
> +; CHECK-BE: mul [[PART2:x[0-9]+]], x0, x3
>  ; CHECK-BE: mul x1, x1, x3
> 
>    %prod = mul i128 %lhs, %rhs
> 
> 
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> 
> 
> 
> -- 
> Best Regards,
> 
> Kevin Qin
> 
> 
> 
> -- 
> Best Regards,
> 
> Kevin Qin

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