|  | //===- MipsInstructionSelector.cpp ------------------------------*- C++ -*-===// | 
|  | // | 
|  | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | // See https://llvm.org/LICENSE.txt for license information. | 
|  | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | /// \file | 
|  | /// This file implements the targeting of the InstructionSelector class for | 
|  | /// Mips. | 
|  | /// \todo This should be generated by TableGen. | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "MCTargetDesc/MipsInstPrinter.h" | 
|  | #include "MipsMachineFunction.h" | 
|  | #include "MipsRegisterBankInfo.h" | 
|  | #include "MipsTargetMachine.h" | 
|  | #include "llvm/CodeGen/GlobalISel/InstructionSelectorImpl.h" | 
|  | #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h" | 
|  | #include "llvm/CodeGen/MachineJumpTableInfo.h" | 
|  | #include "llvm/IR/IntrinsicsMips.h" | 
|  |  | 
|  | #define DEBUG_TYPE "mips-isel" | 
|  |  | 
|  | using namespace llvm; | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | #define GET_GLOBALISEL_PREDICATE_BITSET | 
|  | #include "MipsGenGlobalISel.inc" | 
|  | #undef GET_GLOBALISEL_PREDICATE_BITSET | 
|  |  | 
|  | class MipsInstructionSelector : public InstructionSelector { | 
|  | public: | 
|  | MipsInstructionSelector(const MipsTargetMachine &TM, const MipsSubtarget &STI, | 
|  | const MipsRegisterBankInfo &RBI); | 
|  |  | 
|  | bool select(MachineInstr &I) override; | 
|  | static const char *getName() { return DEBUG_TYPE; } | 
|  |  | 
|  | private: | 
|  | bool selectImpl(MachineInstr &I, CodeGenCoverage &CoverageInfo) const; | 
|  | bool isRegInGprb(Register Reg, MachineRegisterInfo &MRI) const; | 
|  | bool isRegInFprb(Register Reg, MachineRegisterInfo &MRI) const; | 
|  | bool materialize32BitImm(Register DestReg, APInt Imm, | 
|  | MachineIRBuilder &B) const; | 
|  | bool selectCopy(MachineInstr &I, MachineRegisterInfo &MRI) const; | 
|  | const TargetRegisterClass * | 
|  | getRegClassForTypeOnBank(Register Reg, MachineRegisterInfo &MRI) const; | 
|  | unsigned selectLoadStoreOpCode(MachineInstr &I, | 
|  | MachineRegisterInfo &MRI) const; | 
|  | bool buildUnalignedStore(MachineInstr &I, unsigned Opc, | 
|  | MachineOperand &BaseAddr, unsigned Offset, | 
|  | MachineMemOperand *MMO) const; | 
|  | bool buildUnalignedLoad(MachineInstr &I, unsigned Opc, Register Dest, | 
|  | MachineOperand &BaseAddr, unsigned Offset, | 
|  | Register TiedDest, MachineMemOperand *MMO) const; | 
|  |  | 
|  | const MipsTargetMachine &TM; | 
|  | const MipsSubtarget &STI; | 
|  | const MipsInstrInfo &TII; | 
|  | const MipsRegisterInfo &TRI; | 
|  | const MipsRegisterBankInfo &RBI; | 
|  |  | 
|  | #define GET_GLOBALISEL_PREDICATES_DECL | 
|  | #include "MipsGenGlobalISel.inc" | 
|  | #undef GET_GLOBALISEL_PREDICATES_DECL | 
|  |  | 
|  | #define GET_GLOBALISEL_TEMPORARIES_DECL | 
|  | #include "MipsGenGlobalISel.inc" | 
|  | #undef GET_GLOBALISEL_TEMPORARIES_DECL | 
|  | }; | 
|  |  | 
|  | } // end anonymous namespace | 
|  |  | 
|  | #define GET_GLOBALISEL_IMPL | 
|  | #include "MipsGenGlobalISel.inc" | 
|  | #undef GET_GLOBALISEL_IMPL | 
|  |  | 
|  | MipsInstructionSelector::MipsInstructionSelector( | 
|  | const MipsTargetMachine &TM, const MipsSubtarget &STI, | 
|  | const MipsRegisterBankInfo &RBI) | 
|  | : TM(TM), STI(STI), TII(*STI.getInstrInfo()), TRI(*STI.getRegisterInfo()), | 
|  | RBI(RBI), | 
|  |  | 
|  | #define GET_GLOBALISEL_PREDICATES_INIT | 
|  | #include "MipsGenGlobalISel.inc" | 
|  | #undef GET_GLOBALISEL_PREDICATES_INIT | 
|  | #define GET_GLOBALISEL_TEMPORARIES_INIT | 
|  | #include "MipsGenGlobalISel.inc" | 
|  | #undef GET_GLOBALISEL_TEMPORARIES_INIT | 
|  | { | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::isRegInGprb(Register Reg, | 
|  | MachineRegisterInfo &MRI) const { | 
|  | return RBI.getRegBank(Reg, MRI, TRI)->getID() == Mips::GPRBRegBankID; | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::isRegInFprb(Register Reg, | 
|  | MachineRegisterInfo &MRI) const { | 
|  | return RBI.getRegBank(Reg, MRI, TRI)->getID() == Mips::FPRBRegBankID; | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::selectCopy(MachineInstr &I, | 
|  | MachineRegisterInfo &MRI) const { | 
|  | Register DstReg = I.getOperand(0).getReg(); | 
|  | if (DstReg.isPhysical()) | 
|  | return true; | 
|  |  | 
|  | const TargetRegisterClass *RC = getRegClassForTypeOnBank(DstReg, MRI); | 
|  | if (!RBI.constrainGenericRegister(DstReg, *RC, MRI)) { | 
|  | LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode()) | 
|  | << " operand\n"); | 
|  | return false; | 
|  | } | 
|  | return true; | 
|  | } | 
|  |  | 
|  | const TargetRegisterClass *MipsInstructionSelector::getRegClassForTypeOnBank( | 
|  | Register Reg, MachineRegisterInfo &MRI) const { | 
|  | const LLT Ty = MRI.getType(Reg); | 
|  | const unsigned TySize = Ty.getSizeInBits(); | 
|  |  | 
|  | if (isRegInGprb(Reg, MRI)) { | 
|  | assert((Ty.isScalar() || Ty.isPointer()) && TySize == 32 && | 
|  | "Register class not available for LLT, register bank combination"); | 
|  | return &Mips::GPR32RegClass; | 
|  | } | 
|  |  | 
|  | if (isRegInFprb(Reg, MRI)) { | 
|  | if (Ty.isScalar()) { | 
|  | assert((TySize == 32 || TySize == 64) && | 
|  | "Register class not available for LLT, register bank combination"); | 
|  | if (TySize == 32) | 
|  | return &Mips::FGR32RegClass; | 
|  | return STI.isFP64bit() ? &Mips::FGR64RegClass : &Mips::AFGR64RegClass; | 
|  | } | 
|  | } | 
|  |  | 
|  | llvm_unreachable("Unsupported register bank."); | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::materialize32BitImm(Register DestReg, APInt Imm, | 
|  | MachineIRBuilder &B) const { | 
|  | assert(Imm.getBitWidth() == 32 && "Unsupported immediate size."); | 
|  | // Ori zero extends immediate. Used for values with zeros in high 16 bits. | 
|  | if (Imm.getHiBits(16).isZero()) { | 
|  | MachineInstr *Inst = | 
|  | B.buildInstr(Mips::ORi, {DestReg}, {Register(Mips::ZERO)}) | 
|  | .addImm(Imm.getLoBits(16).getLimitedValue()); | 
|  | return constrainSelectedInstRegOperands(*Inst, TII, TRI, RBI); | 
|  | } | 
|  | // Lui places immediate in high 16 bits and sets low 16 bits to zero. | 
|  | if (Imm.getLoBits(16).isZero()) { | 
|  | MachineInstr *Inst = B.buildInstr(Mips::LUi, {DestReg}, {}) | 
|  | .addImm(Imm.getHiBits(16).getLimitedValue()); | 
|  | return constrainSelectedInstRegOperands(*Inst, TII, TRI, RBI); | 
|  | } | 
|  | // ADDiu sign extends immediate. Used for values with 1s in high 17 bits. | 
|  | if (Imm.isSignedIntN(16)) { | 
|  | MachineInstr *Inst = | 
|  | B.buildInstr(Mips::ADDiu, {DestReg}, {Register(Mips::ZERO)}) | 
|  | .addImm(Imm.getLoBits(16).getLimitedValue()); | 
|  | return constrainSelectedInstRegOperands(*Inst, TII, TRI, RBI); | 
|  | } | 
|  | // Values that cannot be materialized with single immediate instruction. | 
|  | Register LUiReg = B.getMRI()->createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineInstr *LUi = B.buildInstr(Mips::LUi, {LUiReg}, {}) | 
|  | .addImm(Imm.getHiBits(16).getLimitedValue()); | 
|  | MachineInstr *ORi = B.buildInstr(Mips::ORi, {DestReg}, {LUiReg}) | 
|  | .addImm(Imm.getLoBits(16).getLimitedValue()); | 
|  | if (!constrainSelectedInstRegOperands(*LUi, TII, TRI, RBI)) | 
|  | return false; | 
|  | if (!constrainSelectedInstRegOperands(*ORi, TII, TRI, RBI)) | 
|  | return false; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | /// When I.getOpcode() is returned, we failed to select MIPS instruction opcode. | 
|  | unsigned | 
|  | MipsInstructionSelector::selectLoadStoreOpCode(MachineInstr &I, | 
|  | MachineRegisterInfo &MRI) const { | 
|  | const Register ValueReg = I.getOperand(0).getReg(); | 
|  | const LLT Ty = MRI.getType(ValueReg); | 
|  | const unsigned TySize = Ty.getSizeInBits(); | 
|  | const unsigned MemSizeInBytes = (*I.memoperands_begin())->getSize(); | 
|  | unsigned Opc = I.getOpcode(); | 
|  | const bool isStore = Opc == TargetOpcode::G_STORE; | 
|  |  | 
|  | if (isRegInGprb(ValueReg, MRI)) { | 
|  | assert(((Ty.isScalar() && TySize == 32) || | 
|  | (Ty.isPointer() && TySize == 32 && MemSizeInBytes == 4)) && | 
|  | "Unsupported register bank, LLT, MemSizeInBytes combination"); | 
|  | (void)TySize; | 
|  | if (isStore) | 
|  | switch (MemSizeInBytes) { | 
|  | case 4: | 
|  | return Mips::SW; | 
|  | case 2: | 
|  | return Mips::SH; | 
|  | case 1: | 
|  | return Mips::SB; | 
|  | default: | 
|  | return Opc; | 
|  | } | 
|  | else | 
|  | // Unspecified extending load is selected into zeroExtending load. | 
|  | switch (MemSizeInBytes) { | 
|  | case 4: | 
|  | return Mips::LW; | 
|  | case 2: | 
|  | return Opc == TargetOpcode::G_SEXTLOAD ? Mips::LH : Mips::LHu; | 
|  | case 1: | 
|  | return Opc == TargetOpcode::G_SEXTLOAD ? Mips::LB : Mips::LBu; | 
|  | default: | 
|  | return Opc; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (isRegInFprb(ValueReg, MRI)) { | 
|  | if (Ty.isScalar()) { | 
|  | assert(((TySize == 32 && MemSizeInBytes == 4) || | 
|  | (TySize == 64 && MemSizeInBytes == 8)) && | 
|  | "Unsupported register bank, LLT, MemSizeInBytes combination"); | 
|  |  | 
|  | if (MemSizeInBytes == 4) | 
|  | return isStore ? Mips::SWC1 : Mips::LWC1; | 
|  |  | 
|  | if (STI.isFP64bit()) | 
|  | return isStore ? Mips::SDC164 : Mips::LDC164; | 
|  | return isStore ? Mips::SDC1 : Mips::LDC1; | 
|  | } | 
|  |  | 
|  | if (Ty.isVector()) { | 
|  | assert(STI.hasMSA() && "Vector instructions require target with MSA."); | 
|  | assert((TySize == 128 && MemSizeInBytes == 16) && | 
|  | "Unsupported register bank, LLT, MemSizeInBytes combination"); | 
|  | switch (Ty.getElementType().getSizeInBits()) { | 
|  | case 8: | 
|  | return isStore ? Mips::ST_B : Mips::LD_B; | 
|  | case 16: | 
|  | return isStore ? Mips::ST_H : Mips::LD_H; | 
|  | case 32: | 
|  | return isStore ? Mips::ST_W : Mips::LD_W; | 
|  | case 64: | 
|  | return isStore ? Mips::ST_D : Mips::LD_D; | 
|  | default: | 
|  | return Opc; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | return Opc; | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::buildUnalignedStore( | 
|  | MachineInstr &I, unsigned Opc, MachineOperand &BaseAddr, unsigned Offset, | 
|  | MachineMemOperand *MMO) const { | 
|  | MachineInstr *NewInst = | 
|  | BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(BaseAddr) | 
|  | .addImm(Offset) | 
|  | .addMemOperand(MMO); | 
|  | if (!constrainSelectedInstRegOperands(*NewInst, TII, TRI, RBI)) | 
|  | return false; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::buildUnalignedLoad( | 
|  | MachineInstr &I, unsigned Opc, Register Dest, MachineOperand &BaseAddr, | 
|  | unsigned Offset, Register TiedDest, MachineMemOperand *MMO) const { | 
|  | MachineInstr *NewInst = | 
|  | BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc)) | 
|  | .addDef(Dest) | 
|  | .add(BaseAddr) | 
|  | .addImm(Offset) | 
|  | .addUse(TiedDest) | 
|  | .addMemOperand(*I.memoperands_begin()); | 
|  | if (!constrainSelectedInstRegOperands(*NewInst, TII, TRI, RBI)) | 
|  | return false; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool MipsInstructionSelector::select(MachineInstr &I) { | 
|  |  | 
|  | MachineBasicBlock &MBB = *I.getParent(); | 
|  | MachineFunction &MF = *MBB.getParent(); | 
|  | MachineRegisterInfo &MRI = MF.getRegInfo(); | 
|  |  | 
|  | if (!isPreISelGenericOpcode(I.getOpcode())) { | 
|  | if (I.isCopy()) | 
|  | return selectCopy(I, MRI); | 
|  |  | 
|  | return true; | 
|  | } | 
|  |  | 
|  | if (I.getOpcode() == Mips::G_MUL && | 
|  | isRegInGprb(I.getOperand(0).getReg(), MRI)) { | 
|  | MachineInstr *Mul = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::MUL)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(I.getOperand(1)) | 
|  | .add(I.getOperand(2)); | 
|  | if (!constrainSelectedInstRegOperands(*Mul, TII, TRI, RBI)) | 
|  | return false; | 
|  | Mul->getOperand(3).setIsDead(true); | 
|  | Mul->getOperand(4).setIsDead(true); | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | if (selectImpl(I, *CoverageInfo)) | 
|  | return true; | 
|  |  | 
|  | MachineInstr *MI = nullptr; | 
|  | using namespace TargetOpcode; | 
|  |  | 
|  | switch (I.getOpcode()) { | 
|  | case G_UMULH: { | 
|  | Register PseudoMULTuReg = MRI.createVirtualRegister(&Mips::ACC64RegClass); | 
|  | MachineInstr *PseudoMULTu, *PseudoMove; | 
|  |  | 
|  | PseudoMULTu = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::PseudoMULTu)) | 
|  | .addDef(PseudoMULTuReg) | 
|  | .add(I.getOperand(1)) | 
|  | .add(I.getOperand(2)); | 
|  | if (!constrainSelectedInstRegOperands(*PseudoMULTu, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | PseudoMove = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::PseudoMFHI)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addUse(PseudoMULTuReg); | 
|  | if (!constrainSelectedInstRegOperands(*PseudoMove, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_PTR_ADD: { | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDu)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(I.getOperand(1)) | 
|  | .add(I.getOperand(2)); | 
|  | break; | 
|  | } | 
|  | case G_INTTOPTR: | 
|  | case G_PTRTOINT: { | 
|  | I.setDesc(TII.get(COPY)); | 
|  | return selectCopy(I, MRI); | 
|  | } | 
|  | case G_FRAME_INDEX: { | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDiu)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(I.getOperand(1)) | 
|  | .addImm(0); | 
|  | break; | 
|  | } | 
|  | case G_BRCOND: { | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::BNE)) | 
|  | .add(I.getOperand(0)) | 
|  | .addUse(Mips::ZERO) | 
|  | .add(I.getOperand(1)); | 
|  | break; | 
|  | } | 
|  | case G_BRJT: { | 
|  | unsigned EntrySize = | 
|  | MF.getJumpTableInfo()->getEntrySize(MF.getDataLayout()); | 
|  | assert(isPowerOf2_32(EntrySize) && | 
|  | "Non-power-of-two jump-table entry size not supported."); | 
|  |  | 
|  | Register JTIndex = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineInstr *SLL = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::SLL)) | 
|  | .addDef(JTIndex) | 
|  | .addUse(I.getOperand(2).getReg()) | 
|  | .addImm(Log2_32(EntrySize)); | 
|  | if (!constrainSelectedInstRegOperands(*SLL, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | Register DestAddress = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineInstr *ADDu = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDu)) | 
|  | .addDef(DestAddress) | 
|  | .addUse(I.getOperand(0).getReg()) | 
|  | .addUse(JTIndex); | 
|  | if (!constrainSelectedInstRegOperands(*ADDu, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | Register Dest = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineInstr *LW = | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::LW)) | 
|  | .addDef(Dest) | 
|  | .addUse(DestAddress) | 
|  | .addJumpTableIndex(I.getOperand(1).getIndex(), MipsII::MO_ABS_LO) | 
|  | .addMemOperand(MF.getMachineMemOperand( | 
|  | MachinePointerInfo(), MachineMemOperand::MOLoad, 4, Align(4))); | 
|  | if (!constrainSelectedInstRegOperands(*LW, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | if (MF.getTarget().isPositionIndependent()) { | 
|  | Register DestTmp = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | LW->getOperand(0).setReg(DestTmp); | 
|  | MachineInstr *ADDu = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDu)) | 
|  | .addDef(Dest) | 
|  | .addUse(DestTmp) | 
|  | .addUse(MF.getInfo<MipsFunctionInfo>() | 
|  | ->getGlobalBaseRegForGlobalISel(MF)); | 
|  | if (!constrainSelectedInstRegOperands(*ADDu, TII, TRI, RBI)) | 
|  | return false; | 
|  | } | 
|  |  | 
|  | MachineInstr *Branch = | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::PseudoIndirectBranch)) | 
|  | .addUse(Dest); | 
|  | if (!constrainSelectedInstRegOperands(*Branch, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_BRINDIRECT: { | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::PseudoIndirectBranch)) | 
|  | .add(I.getOperand(0)); | 
|  | break; | 
|  | } | 
|  | case G_PHI: { | 
|  | const Register DestReg = I.getOperand(0).getReg(); | 
|  |  | 
|  | const TargetRegisterClass *DefRC = nullptr; | 
|  | if (DestReg.isPhysical()) | 
|  | DefRC = TRI.getRegClass(DestReg); | 
|  | else | 
|  | DefRC = getRegClassForTypeOnBank(DestReg, MRI); | 
|  |  | 
|  | I.setDesc(TII.get(TargetOpcode::PHI)); | 
|  | return RBI.constrainGenericRegister(DestReg, *DefRC, MRI); | 
|  | } | 
|  | case G_STORE: | 
|  | case G_LOAD: | 
|  | case G_ZEXTLOAD: | 
|  | case G_SEXTLOAD: { | 
|  | auto MMO = *I.memoperands_begin(); | 
|  | MachineOperand BaseAddr = I.getOperand(1); | 
|  | int64_t SignedOffset = 0; | 
|  | // Try to fold load/store + G_PTR_ADD + G_CONSTANT | 
|  | // %SignedOffset:(s32) = G_CONSTANT i32 16_bit_signed_immediate | 
|  | // %Addr:(p0) = G_PTR_ADD %BaseAddr, %SignedOffset | 
|  | // %LoadResult/%StoreSrc = load/store %Addr(p0) | 
|  | // into: | 
|  | // %LoadResult/%StoreSrc = NewOpc %BaseAddr(p0), 16_bit_signed_immediate | 
|  |  | 
|  | MachineInstr *Addr = MRI.getVRegDef(I.getOperand(1).getReg()); | 
|  | if (Addr->getOpcode() == G_PTR_ADD) { | 
|  | MachineInstr *Offset = MRI.getVRegDef(Addr->getOperand(2).getReg()); | 
|  | if (Offset->getOpcode() == G_CONSTANT) { | 
|  | APInt OffsetValue = Offset->getOperand(1).getCImm()->getValue(); | 
|  | if (OffsetValue.isSignedIntN(16)) { | 
|  | BaseAddr = Addr->getOperand(1); | 
|  | SignedOffset = OffsetValue.getSExtValue(); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // Unaligned memory access | 
|  | if (MMO->getAlign() < MMO->getSize() && | 
|  | !STI.systemSupportsUnalignedAccess()) { | 
|  | if (MMO->getSize() != 4 || !isRegInGprb(I.getOperand(0).getReg(), MRI)) | 
|  | return false; | 
|  |  | 
|  | if (I.getOpcode() == G_STORE) { | 
|  | if (!buildUnalignedStore(I, Mips::SWL, BaseAddr, SignedOffset + 3, MMO)) | 
|  | return false; | 
|  | if (!buildUnalignedStore(I, Mips::SWR, BaseAddr, SignedOffset, MMO)) | 
|  | return false; | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | if (I.getOpcode() == G_LOAD) { | 
|  | Register ImplDef = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::IMPLICIT_DEF)) | 
|  | .addDef(ImplDef); | 
|  | Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | if (!buildUnalignedLoad(I, Mips::LWL, Tmp, BaseAddr, SignedOffset + 3, | 
|  | ImplDef, MMO)) | 
|  | return false; | 
|  | if (!buildUnalignedLoad(I, Mips::LWR, I.getOperand(0).getReg(), | 
|  | BaseAddr, SignedOffset, Tmp, MMO)) | 
|  | return false; | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | return false; | 
|  | } | 
|  |  | 
|  | const unsigned NewOpc = selectLoadStoreOpCode(I, MRI); | 
|  | if (NewOpc == I.getOpcode()) | 
|  | return false; | 
|  |  | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(NewOpc)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(BaseAddr) | 
|  | .addImm(SignedOffset) | 
|  | .addMemOperand(MMO); | 
|  | break; | 
|  | } | 
|  | case G_UDIV: | 
|  | case G_UREM: | 
|  | case G_SDIV: | 
|  | case G_SREM: { | 
|  | Register HILOReg = MRI.createVirtualRegister(&Mips::ACC64RegClass); | 
|  | bool IsSigned = I.getOpcode() == G_SREM || I.getOpcode() == G_SDIV; | 
|  | bool IsDiv = I.getOpcode() == G_UDIV || I.getOpcode() == G_SDIV; | 
|  |  | 
|  | MachineInstr *PseudoDIV, *PseudoMove; | 
|  | PseudoDIV = BuildMI(MBB, I, I.getDebugLoc(), | 
|  | TII.get(IsSigned ? Mips::PseudoSDIV : Mips::PseudoUDIV)) | 
|  | .addDef(HILOReg) | 
|  | .add(I.getOperand(1)) | 
|  | .add(I.getOperand(2)); | 
|  | if (!constrainSelectedInstRegOperands(*PseudoDIV, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | PseudoMove = BuildMI(MBB, I, I.getDebugLoc(), | 
|  | TII.get(IsDiv ? Mips::PseudoMFLO : Mips::PseudoMFHI)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addUse(HILOReg); | 
|  | if (!constrainSelectedInstRegOperands(*PseudoMove, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_SELECT: { | 
|  | // Handle operands with pointer type. | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::MOVN_I_I)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(I.getOperand(2)) | 
|  | .add(I.getOperand(1)) | 
|  | .add(I.getOperand(3)); | 
|  | break; | 
|  | } | 
|  | case G_UNMERGE_VALUES: { | 
|  | if (I.getNumOperands() != 3) | 
|  | return false; | 
|  | Register Src = I.getOperand(2).getReg(); | 
|  | Register Lo = I.getOperand(0).getReg(); | 
|  | Register Hi = I.getOperand(1).getReg(); | 
|  | if (!isRegInFprb(Src, MRI) || | 
|  | !(isRegInGprb(Lo, MRI) && isRegInGprb(Hi, MRI))) | 
|  | return false; | 
|  |  | 
|  | unsigned Opcode = | 
|  | STI.isFP64bit() ? Mips::ExtractElementF64_64 : Mips::ExtractElementF64; | 
|  |  | 
|  | MachineInstr *ExtractLo = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Opcode)) | 
|  | .addDef(Lo) | 
|  | .addUse(Src) | 
|  | .addImm(0); | 
|  | if (!constrainSelectedInstRegOperands(*ExtractLo, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | MachineInstr *ExtractHi = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Opcode)) | 
|  | .addDef(Hi) | 
|  | .addUse(Src) | 
|  | .addImm(1); | 
|  | if (!constrainSelectedInstRegOperands(*ExtractHi, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_IMPLICIT_DEF: { | 
|  | Register Dst = I.getOperand(0).getReg(); | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::IMPLICIT_DEF)) | 
|  | .addDef(Dst); | 
|  |  | 
|  | // Set class based on register bank, there can be fpr and gpr implicit def. | 
|  | MRI.setRegClass(Dst, getRegClassForTypeOnBank(Dst, MRI)); | 
|  | break; | 
|  | } | 
|  | case G_CONSTANT: { | 
|  | MachineIRBuilder B(I); | 
|  | if (!materialize32BitImm(I.getOperand(0).getReg(), | 
|  | I.getOperand(1).getCImm()->getValue(), B)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_FCONSTANT: { | 
|  | const APFloat &FPimm = I.getOperand(1).getFPImm()->getValueAPF(); | 
|  | APInt APImm = FPimm.bitcastToAPInt(); | 
|  | unsigned Size = MRI.getType(I.getOperand(0).getReg()).getSizeInBits(); | 
|  |  | 
|  | if (Size == 32) { | 
|  | Register GPRReg = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineIRBuilder B(I); | 
|  | if (!materialize32BitImm(GPRReg, APImm, B)) | 
|  | return false; | 
|  |  | 
|  | MachineInstrBuilder MTC1 = | 
|  | B.buildInstr(Mips::MTC1, {I.getOperand(0).getReg()}, {GPRReg}); | 
|  | if (!MTC1.constrainAllUses(TII, TRI, RBI)) | 
|  | return false; | 
|  | } | 
|  | if (Size == 64) { | 
|  | Register GPRRegHigh = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | Register GPRRegLow = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineIRBuilder B(I); | 
|  | if (!materialize32BitImm(GPRRegHigh, APImm.getHiBits(32).trunc(32), B)) | 
|  | return false; | 
|  | if (!materialize32BitImm(GPRRegLow, APImm.getLoBits(32).trunc(32), B)) | 
|  | return false; | 
|  |  | 
|  | MachineInstrBuilder PairF64 = B.buildInstr( | 
|  | STI.isFP64bit() ? Mips::BuildPairF64_64 : Mips::BuildPairF64, | 
|  | {I.getOperand(0).getReg()}, {GPRRegLow, GPRRegHigh}); | 
|  | if (!PairF64.constrainAllUses(TII, TRI, RBI)) | 
|  | return false; | 
|  | } | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_FABS: { | 
|  | unsigned Size = MRI.getType(I.getOperand(0).getReg()).getSizeInBits(); | 
|  | unsigned FABSOpcode = | 
|  | Size == 32 ? Mips::FABS_S | 
|  | : STI.isFP64bit() ? Mips::FABS_D64 : Mips::FABS_D32; | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(FABSOpcode)) | 
|  | .add(I.getOperand(0)) | 
|  | .add(I.getOperand(1)); | 
|  | break; | 
|  | } | 
|  | case G_FPTOSI: { | 
|  | unsigned FromSize = MRI.getType(I.getOperand(1).getReg()).getSizeInBits(); | 
|  | unsigned ToSize = MRI.getType(I.getOperand(0).getReg()).getSizeInBits(); | 
|  | (void)ToSize; | 
|  | assert((ToSize == 32) && "Unsupported integer size for G_FPTOSI"); | 
|  | assert((FromSize == 32 || FromSize == 64) && | 
|  | "Unsupported floating point size for G_FPTOSI"); | 
|  |  | 
|  | unsigned Opcode; | 
|  | if (FromSize == 32) | 
|  | Opcode = Mips::TRUNC_W_S; | 
|  | else | 
|  | Opcode = STI.isFP64bit() ? Mips::TRUNC_W_D64 : Mips::TRUNC_W_D32; | 
|  | Register ResultInFPR = MRI.createVirtualRegister(&Mips::FGR32RegClass); | 
|  | MachineInstr *Trunc = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Opcode)) | 
|  | .addDef(ResultInFPR) | 
|  | .addUse(I.getOperand(1).getReg()); | 
|  | if (!constrainSelectedInstRegOperands(*Trunc, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | MachineInstr *Move = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::MFC1)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addUse(ResultInFPR); | 
|  | if (!constrainSelectedInstRegOperands(*Move, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_GLOBAL_VALUE: { | 
|  | const llvm::GlobalValue *GVal = I.getOperand(1).getGlobal(); | 
|  | if (MF.getTarget().isPositionIndependent()) { | 
|  | MachineInstr *LWGOT = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::LW)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addReg(MF.getInfo<MipsFunctionInfo>() | 
|  | ->getGlobalBaseRegForGlobalISel(MF)) | 
|  | .addGlobalAddress(GVal); | 
|  | // Global Values that don't have local linkage are handled differently | 
|  | // when they are part of call sequence. MipsCallLowering::lowerCall | 
|  | // creates G_GLOBAL_VALUE instruction as part of call sequence and adds | 
|  | // MO_GOT_CALL flag when Callee doesn't have local linkage. | 
|  | if (I.getOperand(1).getTargetFlags() == MipsII::MO_GOT_CALL) | 
|  | LWGOT->getOperand(2).setTargetFlags(MipsII::MO_GOT_CALL); | 
|  | else | 
|  | LWGOT->getOperand(2).setTargetFlags(MipsII::MO_GOT); | 
|  | LWGOT->addMemOperand( | 
|  | MF, MF.getMachineMemOperand(MachinePointerInfo::getGOT(MF), | 
|  | MachineMemOperand::MOLoad, 4, Align(4))); | 
|  | if (!constrainSelectedInstRegOperands(*LWGOT, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | if (GVal->hasLocalLinkage()) { | 
|  | Register LWGOTDef = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | LWGOT->getOperand(0).setReg(LWGOTDef); | 
|  |  | 
|  | MachineInstr *ADDiu = | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDiu)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addReg(LWGOTDef) | 
|  | .addGlobalAddress(GVal); | 
|  | ADDiu->getOperand(2).setTargetFlags(MipsII::MO_ABS_LO); | 
|  | if (!constrainSelectedInstRegOperands(*ADDiu, TII, TRI, RBI)) | 
|  | return false; | 
|  | } | 
|  | } else { | 
|  | Register LUiReg = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  |  | 
|  | MachineInstr *LUi = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::LUi)) | 
|  | .addDef(LUiReg) | 
|  | .addGlobalAddress(GVal); | 
|  | LUi->getOperand(1).setTargetFlags(MipsII::MO_ABS_HI); | 
|  | if (!constrainSelectedInstRegOperands(*LUi, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | MachineInstr *ADDiu = | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDiu)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addUse(LUiReg) | 
|  | .addGlobalAddress(GVal); | 
|  | ADDiu->getOperand(2).setTargetFlags(MipsII::MO_ABS_LO); | 
|  | if (!constrainSelectedInstRegOperands(*ADDiu, TII, TRI, RBI)) | 
|  | return false; | 
|  | } | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_JUMP_TABLE: { | 
|  | if (MF.getTarget().isPositionIndependent()) { | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::LW)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addReg(MF.getInfo<MipsFunctionInfo>() | 
|  | ->getGlobalBaseRegForGlobalISel(MF)) | 
|  | .addJumpTableIndex(I.getOperand(1).getIndex(), MipsII::MO_GOT) | 
|  | .addMemOperand(MF.getMachineMemOperand( | 
|  | MachinePointerInfo::getGOT(MF), MachineMemOperand::MOLoad, 4, | 
|  | Align(4))); | 
|  | } else { | 
|  | MI = | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::LUi)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addJumpTableIndex(I.getOperand(1).getIndex(), MipsII::MO_ABS_HI); | 
|  | } | 
|  | break; | 
|  | } | 
|  | case G_ICMP: { | 
|  | struct Instr { | 
|  | unsigned Opcode; | 
|  | Register Def, LHS, RHS; | 
|  | Instr(unsigned Opcode, Register Def, Register LHS, Register RHS) | 
|  | : Opcode(Opcode), Def(Def), LHS(LHS), RHS(RHS){}; | 
|  |  | 
|  | bool hasImm() const { | 
|  | if (Opcode == Mips::SLTiu || Opcode == Mips::XORi) | 
|  | return true; | 
|  | return false; | 
|  | } | 
|  | }; | 
|  |  | 
|  | SmallVector<struct Instr, 2> Instructions; | 
|  | Register ICMPReg = I.getOperand(0).getReg(); | 
|  | Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | Register LHS = I.getOperand(2).getReg(); | 
|  | Register RHS = I.getOperand(3).getReg(); | 
|  | CmpInst::Predicate Cond = | 
|  | static_cast<CmpInst::Predicate>(I.getOperand(1).getPredicate()); | 
|  |  | 
|  | switch (Cond) { | 
|  | case CmpInst::ICMP_EQ: // LHS == RHS -> (LHS ^ RHS) < 1 | 
|  | Instructions.emplace_back(Mips::XOR, Temp, LHS, RHS); | 
|  | Instructions.emplace_back(Mips::SLTiu, ICMPReg, Temp, 1); | 
|  | break; | 
|  | case CmpInst::ICMP_NE: // LHS != RHS -> 0 < (LHS ^ RHS) | 
|  | Instructions.emplace_back(Mips::XOR, Temp, LHS, RHS); | 
|  | Instructions.emplace_back(Mips::SLTu, ICMPReg, Mips::ZERO, Temp); | 
|  | break; | 
|  | case CmpInst::ICMP_UGT: // LHS >  RHS -> RHS < LHS | 
|  | Instructions.emplace_back(Mips::SLTu, ICMPReg, RHS, LHS); | 
|  | break; | 
|  | case CmpInst::ICMP_UGE: // LHS >= RHS -> !(LHS < RHS) | 
|  | Instructions.emplace_back(Mips::SLTu, Temp, LHS, RHS); | 
|  | Instructions.emplace_back(Mips::XORi, ICMPReg, Temp, 1); | 
|  | break; | 
|  | case CmpInst::ICMP_ULT: // LHS <  RHS -> LHS < RHS | 
|  | Instructions.emplace_back(Mips::SLTu, ICMPReg, LHS, RHS); | 
|  | break; | 
|  | case CmpInst::ICMP_ULE: // LHS <= RHS -> !(RHS < LHS) | 
|  | Instructions.emplace_back(Mips::SLTu, Temp, RHS, LHS); | 
|  | Instructions.emplace_back(Mips::XORi, ICMPReg, Temp, 1); | 
|  | break; | 
|  | case CmpInst::ICMP_SGT: // LHS >  RHS -> RHS < LHS | 
|  | Instructions.emplace_back(Mips::SLT, ICMPReg, RHS, LHS); | 
|  | break; | 
|  | case CmpInst::ICMP_SGE: // LHS >= RHS -> !(LHS < RHS) | 
|  | Instructions.emplace_back(Mips::SLT, Temp, LHS, RHS); | 
|  | Instructions.emplace_back(Mips::XORi, ICMPReg, Temp, 1); | 
|  | break; | 
|  | case CmpInst::ICMP_SLT: // LHS <  RHS -> LHS < RHS | 
|  | Instructions.emplace_back(Mips::SLT, ICMPReg, LHS, RHS); | 
|  | break; | 
|  | case CmpInst::ICMP_SLE: // LHS <= RHS -> !(RHS < LHS) | 
|  | Instructions.emplace_back(Mips::SLT, Temp, RHS, LHS); | 
|  | Instructions.emplace_back(Mips::XORi, ICMPReg, Temp, 1); | 
|  | break; | 
|  | default: | 
|  | return false; | 
|  | } | 
|  |  | 
|  | MachineIRBuilder B(I); | 
|  | for (const struct Instr &Instruction : Instructions) { | 
|  | MachineInstrBuilder MIB = B.buildInstr( | 
|  | Instruction.Opcode, {Instruction.Def}, {Instruction.LHS}); | 
|  |  | 
|  | if (Instruction.hasImm()) | 
|  | MIB.addImm(Instruction.RHS); | 
|  | else | 
|  | MIB.addUse(Instruction.RHS); | 
|  |  | 
|  | if (!MIB.constrainAllUses(TII, TRI, RBI)) | 
|  | return false; | 
|  | } | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_FCMP: { | 
|  | unsigned MipsFCMPCondCode; | 
|  | bool isLogicallyNegated; | 
|  | switch (CmpInst::Predicate Cond = static_cast<CmpInst::Predicate>( | 
|  | I.getOperand(1).getPredicate())) { | 
|  | case CmpInst::FCMP_UNO: // Unordered | 
|  | case CmpInst::FCMP_ORD: // Ordered (OR) | 
|  | MipsFCMPCondCode = Mips::FCOND_UN; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_UNO; | 
|  | break; | 
|  | case CmpInst::FCMP_OEQ: // Equal | 
|  | case CmpInst::FCMP_UNE: // Not Equal (NEQ) | 
|  | MipsFCMPCondCode = Mips::FCOND_OEQ; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_OEQ; | 
|  | break; | 
|  | case CmpInst::FCMP_UEQ: // Unordered or Equal | 
|  | case CmpInst::FCMP_ONE: // Ordered or Greater Than or Less Than (OGL) | 
|  | MipsFCMPCondCode = Mips::FCOND_UEQ; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_UEQ; | 
|  | break; | 
|  | case CmpInst::FCMP_OLT: // Ordered or Less Than | 
|  | case CmpInst::FCMP_UGE: // Unordered or Greater Than or Equal (UGE) | 
|  | MipsFCMPCondCode = Mips::FCOND_OLT; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_OLT; | 
|  | break; | 
|  | case CmpInst::FCMP_ULT: // Unordered or Less Than | 
|  | case CmpInst::FCMP_OGE: // Ordered or Greater Than or Equal (OGE) | 
|  | MipsFCMPCondCode = Mips::FCOND_ULT; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_ULT; | 
|  | break; | 
|  | case CmpInst::FCMP_OLE: // Ordered or Less Than or Equal | 
|  | case CmpInst::FCMP_UGT: // Unordered or Greater Than (UGT) | 
|  | MipsFCMPCondCode = Mips::FCOND_OLE; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_OLE; | 
|  | break; | 
|  | case CmpInst::FCMP_ULE: // Unordered or Less Than or Equal | 
|  | case CmpInst::FCMP_OGT: // Ordered or Greater Than (OGT) | 
|  | MipsFCMPCondCode = Mips::FCOND_ULE; | 
|  | isLogicallyNegated = Cond != CmpInst::FCMP_ULE; | 
|  | break; | 
|  | default: | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // Default compare result in gpr register will be `true`. | 
|  | // We will move `false` (MIPS::Zero) to gpr result when fcmp gives false | 
|  | // using MOVF_I. When orignal predicate (Cond) is logically negated | 
|  | // MipsFCMPCondCode, result is inverted i.e. MOVT_I is used. | 
|  | unsigned MoveOpcode = isLogicallyNegated ? Mips::MOVT_I : Mips::MOVF_I; | 
|  |  | 
|  | Register TrueInReg = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDiu)) | 
|  | .addDef(TrueInReg) | 
|  | .addUse(Mips::ZERO) | 
|  | .addImm(1); | 
|  |  | 
|  | unsigned Size = MRI.getType(I.getOperand(2).getReg()).getSizeInBits(); | 
|  | unsigned FCMPOpcode = | 
|  | Size == 32 ? Mips::FCMP_S32 | 
|  | : STI.isFP64bit() ? Mips::FCMP_D64 : Mips::FCMP_D32; | 
|  | MachineInstr *FCMP = BuildMI(MBB, I, I.getDebugLoc(), TII.get(FCMPOpcode)) | 
|  | .addUse(I.getOperand(2).getReg()) | 
|  | .addUse(I.getOperand(3).getReg()) | 
|  | .addImm(MipsFCMPCondCode); | 
|  | if (!constrainSelectedInstRegOperands(*FCMP, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | MachineInstr *Move = BuildMI(MBB, I, I.getDebugLoc(), TII.get(MoveOpcode)) | 
|  | .addDef(I.getOperand(0).getReg()) | 
|  | .addUse(Mips::ZERO) | 
|  | .addUse(Mips::FCC0) | 
|  | .addUse(TrueInReg); | 
|  | if (!constrainSelectedInstRegOperands(*Move, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | case G_FENCE: { | 
|  | MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::SYNC)).addImm(0); | 
|  | break; | 
|  | } | 
|  | case G_VASTART: { | 
|  | MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>(); | 
|  | int FI = FuncInfo->getVarArgsFrameIndex(); | 
|  |  | 
|  | Register LeaReg = MRI.createVirtualRegister(&Mips::GPR32RegClass); | 
|  | MachineInstr *LEA_ADDiu = | 
|  | BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::LEA_ADDiu)) | 
|  | .addDef(LeaReg) | 
|  | .addFrameIndex(FI) | 
|  | .addImm(0); | 
|  | if (!constrainSelectedInstRegOperands(*LEA_ADDiu, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | MachineInstr *Store = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::SW)) | 
|  | .addUse(LeaReg) | 
|  | .addUse(I.getOperand(0).getReg()) | 
|  | .addImm(0); | 
|  | if (!constrainSelectedInstRegOperands(*Store, TII, TRI, RBI)) | 
|  | return false; | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return true; | 
|  | } | 
|  | default: | 
|  | return false; | 
|  | } | 
|  |  | 
|  | I.eraseFromParent(); | 
|  | return constrainSelectedInstRegOperands(*MI, TII, TRI, RBI); | 
|  | } | 
|  |  | 
|  | namespace llvm { | 
|  | InstructionSelector *createMipsInstructionSelector(const MipsTargetMachine &TM, | 
|  | MipsSubtarget &Subtarget, | 
|  | MipsRegisterBankInfo &RBI) { | 
|  | return new MipsInstructionSelector(TM, Subtarget, RBI); | 
|  | } | 
|  | } // end namespace llvm |