//===-- MipsastISel.cpp - Mips FastISel implementation //---------------------===// #include "MipsCCState.h" #include "MipsInstrInfo.h" #include "MipsISelLowering.h" #include "MipsMachineFunction.h" #include "MipsRegisterInfo.h" #include "MipsSubtarget.h" #include "MipsTargetMachine.h" #include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/CodeGen/FastISel.h" #include "llvm/CodeGen/FunctionLoweringInfo.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/GlobalAlias.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Target/TargetInstrInfo.h" using namespace llvm; namespace { class MipsFastISel final : public FastISel { // All possible address modes. class Address { public: typedef enum { RegBase, FrameIndexBase } BaseKind; private: BaseKind Kind; union { unsigned Reg; int FI; } Base; int64_t Offset; const GlobalValue *GV; public: // Innocuous defaults for our address. Address() : Kind(RegBase), Offset(0), GV(0) { Base.Reg = 0; } void setKind(BaseKind K) { Kind = K; } BaseKind getKind() const { return Kind; } bool isRegBase() const { return Kind == RegBase; } bool isFIBase() const { return Kind == FrameIndexBase; } void setReg(unsigned Reg) { assert(isRegBase() && "Invalid base register access!"); Base.Reg = Reg; } unsigned getReg() const { assert(isRegBase() && "Invalid base register access!"); return Base.Reg; } void setFI(unsigned FI) { assert(isFIBase() && "Invalid base frame index access!"); Base.FI = FI; } unsigned getFI() const { assert(isFIBase() && "Invalid base frame index access!"); return Base.FI; } void setOffset(int64_t Offset_) { Offset = Offset_; } int64_t getOffset() const { return Offset; } void setGlobalValue(const GlobalValue *G) { GV = G; } const GlobalValue *getGlobalValue() { return GV; } }; /// Subtarget - Keep a pointer to the MipsSubtarget around so that we can /// make the right decision when generating code for different targets. const TargetMachine &TM; const MipsSubtarget *Subtarget; const TargetInstrInfo &TII; const TargetLowering &TLI; MipsFunctionInfo *MFI; // Convenience variables to avoid some queries. LLVMContext *Context; bool fastLowerCall(CallLoweringInfo &CLI) override; bool fastLowerIntrinsicCall(const IntrinsicInst *II) override; bool TargetSupported; bool UnsupportedFPMode; // To allow fast-isel to proceed and just not handle // floating point but not reject doing fast-isel in other // situations private: // Selection routines. bool selectLogicalOp(const Instruction *I); bool selectLoad(const Instruction *I); bool selectStore(const Instruction *I); bool selectBranch(const Instruction *I); bool selectSelect(const Instruction *I); bool selectCmp(const Instruction *I); bool selectFPExt(const Instruction *I); bool selectFPTrunc(const Instruction *I); bool selectFPToInt(const Instruction *I, bool IsSigned); bool selectRet(const Instruction *I); bool selectTrunc(const Instruction *I); bool selectIntExt(const Instruction *I); bool selectShift(const Instruction *I); bool selectDivRem(const Instruction *I, unsigned ISDOpcode); // Utility helper routines. bool isTypeLegal(Type *Ty, MVT &VT); bool isTypeSupported(Type *Ty, MVT &VT); bool isLoadTypeLegal(Type *Ty, MVT &VT); bool computeAddress(const Value *Obj, Address &Addr); bool computeCallAddress(const Value *V, Address &Addr); void simplifyAddress(Address &Addr); // Emit helper routines. bool emitCmp(unsigned DestReg, const CmpInst *CI); bool emitLoad(MVT VT, unsigned &ResultReg, Address &Addr, unsigned Alignment = 0); bool emitStore(MVT VT, unsigned SrcReg, Address Addr, MachineMemOperand *MMO = nullptr); bool emitStore(MVT VT, unsigned SrcReg, Address &Addr, unsigned Alignment = 0); unsigned emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, bool isZExt); bool emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg, bool IsZExt); bool emitIntZExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg); bool emitIntSExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg); bool emitIntSExt32r1(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg); bool emitIntSExt32r2(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg); unsigned getRegEnsuringSimpleIntegerWidening(const Value *, bool IsUnsigned); unsigned emitLogicalOp(unsigned ISDOpc, MVT RetVT, const Value *LHS, const Value *RHS); unsigned materializeFP(const ConstantFP *CFP, MVT VT); unsigned materializeGV(const GlobalValue *GV, MVT VT); unsigned materializeInt(const Constant *C, MVT VT); unsigned materialize32BitInt(int64_t Imm, const TargetRegisterClass *RC); unsigned materializeExternalCallSym(MCSymbol *Syn); MachineInstrBuilder emitInst(unsigned Opc) { return BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc)); } MachineInstrBuilder emitInst(unsigned Opc, unsigned DstReg) { return BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DstReg); } MachineInstrBuilder emitInstStore(unsigned Opc, unsigned SrcReg, unsigned MemReg, int64_t MemOffset) { return emitInst(Opc).addReg(SrcReg).addReg(MemReg).addImm(MemOffset); } MachineInstrBuilder emitInstLoad(unsigned Opc, unsigned DstReg, unsigned MemReg, int64_t MemOffset) { return emitInst(Opc, DstReg).addReg(MemReg).addImm(MemOffset); } unsigned fastEmitInst_rr(unsigned MachineInstOpcode, const TargetRegisterClass *RC, unsigned Op0, bool Op0IsKill, unsigned Op1, bool Op1IsKill); // for some reason, this default is not generated by tablegen // so we explicitly generate it here. // unsigned fastEmitInst_riir(uint64_t inst, const TargetRegisterClass *RC, unsigned Op0, bool Op0IsKill, uint64_t imm1, uint64_t imm2, unsigned Op3, bool Op3IsKill) { return 0; } // Call handling routines. private: CCAssignFn *CCAssignFnForCall(CallingConv::ID CC) const; bool processCallArgs(CallLoweringInfo &CLI, SmallVectorImpl<MVT> &ArgVTs, unsigned &NumBytes); bool finishCall(CallLoweringInfo &CLI, MVT RetVT, unsigned NumBytes); public: // Backend specific FastISel code. explicit MipsFastISel(FunctionLoweringInfo &funcInfo, const TargetLibraryInfo *libInfo) : FastISel(funcInfo, libInfo), TM(funcInfo.MF->getTarget()), Subtarget(&funcInfo.MF->getSubtarget<MipsSubtarget>()), TII(*Subtarget->getInstrInfo()), TLI(*Subtarget->getTargetLowering()) { MFI = funcInfo.MF->getInfo<MipsFunctionInfo>(); Context = &funcInfo.Fn->getContext(); bool ISASupported = !Subtarget->hasMips32r6() && Subtarget->hasMips32(); TargetSupported = ISASupported && (TM.getRelocationModel() == Reloc::PIC_) && (static_cast<const MipsTargetMachine &>(TM).getABI().IsO32()); UnsupportedFPMode = Subtarget->isFP64bit(); } unsigned fastMaterializeAlloca(const AllocaInst *AI) override; unsigned fastMaterializeConstant(const Constant *C) override; bool fastSelectInstruction(const Instruction *I) override; #include "MipsGenFastISel.inc" }; } // end anonymous namespace. static bool CC_Mips(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) LLVM_ATTRIBUTE_UNUSED; static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) { llvm_unreachable("should not be called"); } static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) { llvm_unreachable("should not be called"); } #include "MipsGenCallingConv.inc" CCAssignFn *MipsFastISel::CCAssignFnForCall(CallingConv::ID CC) const { return CC_MipsO32; } unsigned MipsFastISel::emitLogicalOp(unsigned ISDOpc, MVT RetVT, const Value *LHS, const Value *RHS) { // Canonicalize immediates to the RHS first. if (isa<ConstantInt>(LHS) && !isa<ConstantInt>(RHS)) std::swap(LHS, RHS); unsigned Opc; switch (ISDOpc) { case ISD::AND: Opc = Mips::AND; break; case ISD::OR: Opc = Mips::OR; break; case ISD::XOR: Opc = Mips::XOR; break; default: llvm_unreachable("unexpected opcode"); } unsigned LHSReg = getRegForValue(LHS); if (!LHSReg) return 0; unsigned RHSReg; if (const auto *C = dyn_cast<ConstantInt>(RHS)) RHSReg = materializeInt(C, MVT::i32); else RHSReg = getRegForValue(RHS); if (!RHSReg) return 0; unsigned ResultReg = createResultReg(&Mips::GPR32RegClass); if (!ResultReg) return 0; emitInst(Opc, ResultReg).addReg(LHSReg).addReg(RHSReg); return ResultReg; } unsigned MipsFastISel::fastMaterializeAlloca(const AllocaInst *AI) { if (!TargetSupported) return 0; assert(TLI.getValueType(DL, AI->getType(), true) == MVT::i32 && "Alloca should always return a pointer."); DenseMap<const AllocaInst *, int>::iterator SI = FuncInfo.StaticAllocaMap.find(AI); if (SI != FuncInfo.StaticAllocaMap.end()) { unsigned ResultReg = createResultReg(&Mips::GPR32RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::LEA_ADDiu), ResultReg) .addFrameIndex(SI->second) .addImm(0); return ResultReg; } return 0; } unsigned MipsFastISel::materializeInt(const Constant *C, MVT VT) { if (VT != MVT::i32 && VT != MVT::i16 && VT != MVT::i8 && VT != MVT::i1) return 0; const TargetRegisterClass *RC = &Mips::GPR32RegClass; const ConstantInt *CI = cast<ConstantInt>(C); return materialize32BitInt(CI->getZExtValue(), RC); } unsigned MipsFastISel::materialize32BitInt(int64_t Imm, const TargetRegisterClass *RC) { unsigned ResultReg = createResultReg(RC); if (isInt<16>(Imm)) { unsigned Opc = Mips::ADDiu; emitInst(Opc, ResultReg).addReg(Mips::ZERO).addImm(Imm); return ResultReg; } else if (isUInt<16>(Imm)) { emitInst(Mips::ORi, ResultReg).addReg(Mips::ZERO).addImm(Imm); return ResultReg; } unsigned Lo = Imm & 0xFFFF; unsigned Hi = (Imm >> 16) & 0xFFFF; if (Lo) { // Both Lo and Hi have nonzero bits. unsigned TmpReg = createResultReg(RC); emitInst(Mips::LUi, TmpReg).addImm(Hi); emitInst(Mips::ORi, ResultReg).addReg(TmpReg).addImm(Lo); } else { emitInst(Mips::LUi, ResultReg).addImm(Hi); } return ResultReg; } unsigned MipsFastISel::materializeFP(const ConstantFP *CFP, MVT VT) { if (UnsupportedFPMode) return 0; int64_t Imm = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); if (VT == MVT::f32) { const TargetRegisterClass *RC = &Mips::FGR32RegClass; unsigned DestReg = createResultReg(RC); unsigned TempReg = materialize32BitInt(Imm, &Mips::GPR32RegClass); emitInst(Mips::MTC1, DestReg).addReg(TempReg); return DestReg; } else if (VT == MVT::f64) { const TargetRegisterClass *RC = &Mips::AFGR64RegClass; unsigned DestReg = createResultReg(RC); unsigned TempReg1 = materialize32BitInt(Imm >> 32, &Mips::GPR32RegClass); unsigned TempReg2 = materialize32BitInt(Imm & 0xFFFFFFFF, &Mips::GPR32RegClass); emitInst(Mips::BuildPairF64, DestReg).addReg(TempReg2).addReg(TempReg1); return DestReg; } return 0; } unsigned MipsFastISel::materializeGV(const GlobalValue *GV, MVT VT) { // For now 32-bit only. if (VT != MVT::i32) return 0; const TargetRegisterClass *RC = &Mips::GPR32RegClass; unsigned DestReg = createResultReg(RC); const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV); bool IsThreadLocal = GVar && GVar->isThreadLocal(); // TLS not supported at this time. if (IsThreadLocal) return 0; emitInst(Mips::LW, DestReg) .addReg(MFI->getGlobalBaseReg()) .addGlobalAddress(GV, 0, MipsII::MO_GOT); if ((GV->hasInternalLinkage() || (GV->hasLocalLinkage() && !isa<Function>(GV)))) { unsigned TempReg = createResultReg(RC); emitInst(Mips::ADDiu, TempReg) .addReg(DestReg) .addGlobalAddress(GV, 0, MipsII::MO_ABS_LO); DestReg = TempReg; } return DestReg; } unsigned MipsFastISel::materializeExternalCallSym(MCSymbol *Sym) { const TargetRegisterClass *RC = &Mips::GPR32RegClass; unsigned DestReg = createResultReg(RC); emitInst(Mips::LW, DestReg) .addReg(MFI->getGlobalBaseReg()) .addSym(Sym, MipsII::MO_GOT); return DestReg; } // Materialize a constant into a register, and return the register // number (or zero if we failed to handle it). unsigned MipsFastISel::fastMaterializeConstant(const Constant *C) { if (!TargetSupported) return 0; EVT CEVT = TLI.getValueType(DL, C->getType(), true); // Only handle simple types. if (!CEVT.isSimple()) return 0; MVT VT = CEVT.getSimpleVT(); if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) return (UnsupportedFPMode) ? 0 : materializeFP(CFP, VT); else if (const GlobalValue *GV = dyn_cast<GlobalValue>(C)) return materializeGV(GV, VT); else if (isa<ConstantInt>(C)) return materializeInt(C, VT); return 0; } bool MipsFastISel::computeAddress(const Value *Obj, Address &Addr) { const User *U = nullptr; unsigned Opcode = Instruction::UserOp1; if (const Instruction *I = dyn_cast<Instruction>(Obj)) { // Don't walk into other basic blocks unless the object is an alloca from // another block, otherwise it may not have a virtual register assigned. if (FuncInfo.StaticAllocaMap.count(static_cast<const AllocaInst *>(Obj)) || FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) { Opcode = I->getOpcode(); U = I; } } else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(Obj)) { Opcode = C->getOpcode(); U = C; } switch (Opcode) { default: break; case Instruction::BitCast: { // Look through bitcasts. return computeAddress(U->getOperand(0), Addr); } case Instruction::GetElementPtr: { Address SavedAddr = Addr; uint64_t TmpOffset = Addr.getOffset(); // Iterate through the GEP folding the constants into offsets where // we can. gep_type_iterator GTI = gep_type_begin(U); for (User::const_op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i, ++GTI) { const Value *Op = *i; if (StructType *STy = dyn_cast<StructType>(*GTI)) { const StructLayout *SL = DL.getStructLayout(STy); unsigned Idx = cast<ConstantInt>(Op)->getZExtValue(); TmpOffset += SL->getElementOffset(Idx); } else { uint64_t S = DL.getTypeAllocSize(GTI.getIndexedType()); for (;;) { if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) { // Constant-offset addressing. TmpOffset += CI->getSExtValue() * S; break; } if (canFoldAddIntoGEP(U, Op)) { // A compatible add with a constant operand. Fold the constant. ConstantInt *CI = cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1)); TmpOffset += CI->getSExtValue() * S; // Iterate on the other operand. Op = cast<AddOperator>(Op)->getOperand(0); continue; } // Unsupported goto unsupported_gep; } } } // Try to grab the base operand now. Addr.setOffset(TmpOffset); if (computeAddress(U->getOperand(0), Addr)) return true; // We failed, restore everything and try the other options. Addr = SavedAddr; unsupported_gep: break; } case Instruction::Alloca: { const AllocaInst *AI = cast<AllocaInst>(Obj); DenseMap<const AllocaInst *, int>::iterator SI = FuncInfo.StaticAllocaMap.find(AI); if (SI != FuncInfo.StaticAllocaMap.end()) { Addr.setKind(Address::FrameIndexBase); Addr.setFI(SI->second); return true; } break; } } Addr.setReg(getRegForValue(Obj)); return Addr.getReg() != 0; } bool MipsFastISel::computeCallAddress(const Value *V, Address &Addr) { const User *U = nullptr; unsigned Opcode = Instruction::UserOp1; if (const auto *I = dyn_cast<Instruction>(V)) { // Check if the value is defined in the same basic block. This information // is crucial to know whether or not folding an operand is valid. if (I->getParent() == FuncInfo.MBB->getBasicBlock()) { Opcode = I->getOpcode(); U = I; } } else if (const auto *C = dyn_cast<ConstantExpr>(V)) { Opcode = C->getOpcode(); U = C; } switch (Opcode) { default: break; case Instruction::BitCast: // Look past bitcasts if its operand is in the same BB. return computeCallAddress(U->getOperand(0), Addr); break; case Instruction::IntToPtr: // Look past no-op inttoptrs if its operand is in the same BB. if (TLI.getValueType(DL, U->getOperand(0)->getType()) == TLI.getPointerTy(DL)) return computeCallAddress(U->getOperand(0), Addr); break; case Instruction::PtrToInt: // Look past no-op ptrtoints if its operand is in the same BB. if (TLI.getValueType(DL, U->getType()) == TLI.getPointerTy(DL)) return computeCallAddress(U->getOperand(0), Addr); break; } if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) { Addr.setGlobalValue(GV); return true; } // If all else fails, try to materialize the value in a register. if (!Addr.getGlobalValue()) { Addr.setReg(getRegForValue(V)); return Addr.getReg() != 0; } return false; } bool MipsFastISel::isTypeLegal(Type *Ty, MVT &VT) { EVT evt = TLI.getValueType(DL, Ty, true); // Only handle simple types. if (evt == MVT::Other || !evt.isSimple()) return false; VT = evt.getSimpleVT(); // Handle all legal types, i.e. a register that will directly hold this // value. return TLI.isTypeLegal(VT); } bool MipsFastISel::isTypeSupported(Type *Ty, MVT &VT) { if (Ty->isVectorTy()) return false; if (isTypeLegal(Ty, VT)) return true; // If this is a type than can be sign or zero-extended to a basic operation // go ahead and accept it now. if (VT == MVT::i1 || VT == MVT::i8 || VT == MVT::i16) return true; return false; } bool MipsFastISel::isLoadTypeLegal(Type *Ty, MVT &VT) { if (isTypeLegal(Ty, VT)) return true; // We will extend this in a later patch: // If this is a type than can be sign or zero-extended to a basic operation // go ahead and accept it now. if (VT == MVT::i8 || VT == MVT::i16) return true; return false; } // Because of how EmitCmp is called with fast-isel, you can // end up with redundant "andi" instructions after the sequences emitted below. // We should try and solve this issue in the future. // bool MipsFastISel::emitCmp(unsigned ResultReg, const CmpInst *CI) { const Value *Left = CI->getOperand(0), *Right = CI->getOperand(1); bool IsUnsigned = CI->isUnsigned(); unsigned LeftReg = getRegEnsuringSimpleIntegerWidening(Left, IsUnsigned); if (LeftReg == 0) return false; unsigned RightReg = getRegEnsuringSimpleIntegerWidening(Right, IsUnsigned); if (RightReg == 0) return false; CmpInst::Predicate P = CI->getPredicate(); switch (P) { default: return false; case CmpInst::ICMP_EQ: { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::XOR, TempReg).addReg(LeftReg).addReg(RightReg); emitInst(Mips::SLTiu, ResultReg).addReg(TempReg).addImm(1); break; } case CmpInst::ICMP_NE: { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::XOR, TempReg).addReg(LeftReg).addReg(RightReg); emitInst(Mips::SLTu, ResultReg).addReg(Mips::ZERO).addReg(TempReg); break; } case CmpInst::ICMP_UGT: { emitInst(Mips::SLTu, ResultReg).addReg(RightReg).addReg(LeftReg); break; } case CmpInst::ICMP_ULT: { emitInst(Mips::SLTu, ResultReg).addReg(LeftReg).addReg(RightReg); break; } case CmpInst::ICMP_UGE: { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::SLTu, TempReg).addReg(LeftReg).addReg(RightReg); emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1); break; } case CmpInst::ICMP_ULE: { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::SLTu, TempReg).addReg(RightReg).addReg(LeftReg); emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1); break; } case CmpInst::ICMP_SGT: { emitInst(Mips::SLT, ResultReg).addReg(RightReg).addReg(LeftReg); break; } case CmpInst::ICMP_SLT: { emitInst(Mips::SLT, ResultReg).addReg(LeftReg).addReg(RightReg); break; } case CmpInst::ICMP_SGE: { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::SLT, TempReg).addReg(LeftReg).addReg(RightReg); emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1); break; } case CmpInst::ICMP_SLE: { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::SLT, TempReg).addReg(RightReg).addReg(LeftReg); emitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1); break; } case CmpInst::FCMP_OEQ: case CmpInst::FCMP_UNE: case CmpInst::FCMP_OLT: case CmpInst::FCMP_OLE: case CmpInst::FCMP_OGT: case CmpInst::FCMP_OGE: { if (UnsupportedFPMode) return false; bool IsFloat = Left->getType()->isFloatTy(); bool IsDouble = Left->getType()->isDoubleTy(); if (!IsFloat && !IsDouble) return false; unsigned Opc, CondMovOpc; switch (P) { case CmpInst::FCMP_OEQ: Opc = IsFloat ? Mips::C_EQ_S : Mips::C_EQ_D32; CondMovOpc = Mips::MOVT_I; break; case CmpInst::FCMP_UNE: Opc = IsFloat ? Mips::C_EQ_S : Mips::C_EQ_D32; CondMovOpc = Mips::MOVF_I; break; case CmpInst::FCMP_OLT: Opc = IsFloat ? Mips::C_OLT_S : Mips::C_OLT_D32; CondMovOpc = Mips::MOVT_I; break; case CmpInst::FCMP_OLE: Opc = IsFloat ? Mips::C_OLE_S : Mips::C_OLE_D32; CondMovOpc = Mips::MOVT_I; break; case CmpInst::FCMP_OGT: Opc = IsFloat ? Mips::C_ULE_S : Mips::C_ULE_D32; CondMovOpc = Mips::MOVF_I; break; case CmpInst::FCMP_OGE: Opc = IsFloat ? Mips::C_ULT_S : Mips::C_ULT_D32; CondMovOpc = Mips::MOVF_I; break; default: llvm_unreachable("Only switching of a subset of CCs."); } unsigned RegWithZero = createResultReg(&Mips::GPR32RegClass); unsigned RegWithOne = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::ADDiu, RegWithZero).addReg(Mips::ZERO).addImm(0); emitInst(Mips::ADDiu, RegWithOne).addReg(Mips::ZERO).addImm(1); emitInst(Opc).addReg(LeftReg).addReg(RightReg).addReg( Mips::FCC0, RegState::ImplicitDefine); MachineInstrBuilder MI = emitInst(CondMovOpc, ResultReg) .addReg(RegWithOne) .addReg(Mips::FCC0) .addReg(RegWithZero, RegState::Implicit); MI->tieOperands(0, 3); break; } } return true; } bool MipsFastISel::emitLoad(MVT VT, unsigned &ResultReg, Address &Addr, unsigned Alignment) { // // more cases will be handled here in following patches. // unsigned Opc; switch (VT.SimpleTy) { case MVT::i32: { ResultReg = createResultReg(&Mips::GPR32RegClass); Opc = Mips::LW; break; } case MVT::i16: { ResultReg = createResultReg(&Mips::GPR32RegClass); Opc = Mips::LHu; break; } case MVT::i8: { ResultReg = createResultReg(&Mips::GPR32RegClass); Opc = Mips::LBu; break; } case MVT::f32: { if (UnsupportedFPMode) return false; ResultReg = createResultReg(&Mips::FGR32RegClass); Opc = Mips::LWC1; break; } case MVT::f64: { if (UnsupportedFPMode) return false; ResultReg = createResultReg(&Mips::AFGR64RegClass); Opc = Mips::LDC1; break; } default: return false; } if (Addr.isRegBase()) { simplifyAddress(Addr); emitInstLoad(Opc, ResultReg, Addr.getReg(), Addr.getOffset()); return true; } if (Addr.isFIBase()) { unsigned FI = Addr.getFI(); unsigned Align = 4; unsigned Offset = Addr.getOffset(); MachineFrameInfo &MFI = *MF->getFrameInfo(); MachineMemOperand *MMO = MF->getMachineMemOperand( MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOLoad, MFI.getObjectSize(FI), Align); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg) .addFrameIndex(FI) .addImm(Offset) .addMemOperand(MMO); return true; } return false; } bool MipsFastISel::emitStore(MVT VT, unsigned SrcReg, Address &Addr, unsigned Alignment) { // // more cases will be handled here in following patches. // unsigned Opc; switch (VT.SimpleTy) { case MVT::i8: Opc = Mips::SB; break; case MVT::i16: Opc = Mips::SH; break; case MVT::i32: Opc = Mips::SW; break; case MVT::f32: if (UnsupportedFPMode) return false; Opc = Mips::SWC1; break; case MVT::f64: if (UnsupportedFPMode) return false; Opc = Mips::SDC1; break; default: return false; } if (Addr.isRegBase()) { simplifyAddress(Addr); emitInstStore(Opc, SrcReg, Addr.getReg(), Addr.getOffset()); return true; } if (Addr.isFIBase()) { unsigned FI = Addr.getFI(); unsigned Align = 4; unsigned Offset = Addr.getOffset(); MachineFrameInfo &MFI = *MF->getFrameInfo(); MachineMemOperand *MMO = MF->getMachineMemOperand( MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOLoad, MFI.getObjectSize(FI), Align); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc)) .addReg(SrcReg) .addFrameIndex(FI) .addImm(Offset) .addMemOperand(MMO); return true; } return false; } bool MipsFastISel::selectLogicalOp(const Instruction *I) { MVT VT; if (!isTypeSupported(I->getType(), VT)) return false; unsigned ResultReg; switch (I->getOpcode()) { default: llvm_unreachable("Unexpected instruction."); case Instruction::And: ResultReg = emitLogicalOp(ISD::AND, VT, I->getOperand(0), I->getOperand(1)); break; case Instruction::Or: ResultReg = emitLogicalOp(ISD::OR, VT, I->getOperand(0), I->getOperand(1)); break; case Instruction::Xor: ResultReg = emitLogicalOp(ISD::XOR, VT, I->getOperand(0), I->getOperand(1)); break; } if (!ResultReg) return false; updateValueMap(I, ResultReg); return true; } bool MipsFastISel::selectLoad(const Instruction *I) { // Atomic loads need special handling. if (cast<LoadInst>(I)->isAtomic()) return false; // Verify we have a legal type before going any further. MVT VT; if (!isLoadTypeLegal(I->getType(), VT)) return false; // See if we can handle this address. Address Addr; if (!computeAddress(I->getOperand(0), Addr)) return false; unsigned ResultReg; if (!emitLoad(VT, ResultReg, Addr, cast<LoadInst>(I)->getAlignment())) return false; updateValueMap(I, ResultReg); return true; } bool MipsFastISel::selectStore(const Instruction *I) { Value *Op0 = I->getOperand(0); unsigned SrcReg = 0; // Atomic stores need special handling. if (cast<StoreInst>(I)->isAtomic()) return false; // Verify we have a legal type before going any further. MVT VT; if (!isLoadTypeLegal(I->getOperand(0)->getType(), VT)) return false; // Get the value to be stored into a register. SrcReg = getRegForValue(Op0); if (SrcReg == 0) return false; // See if we can handle this address. Address Addr; if (!computeAddress(I->getOperand(1), Addr)) return false; if (!emitStore(VT, SrcReg, Addr, cast<StoreInst>(I)->getAlignment())) return false; return true; } // // This can cause a redundant sltiu to be generated. // FIXME: try and eliminate this in a future patch. // bool MipsFastISel::selectBranch(const Instruction *I) { const BranchInst *BI = cast<BranchInst>(I); MachineBasicBlock *BrBB = FuncInfo.MBB; // // TBB is the basic block for the case where the comparison is true. // FBB is the basic block for the case where the comparison is false. // if (cond) goto TBB // goto FBB // TBB: // MachineBasicBlock *TBB = FuncInfo.MBBMap[BI->getSuccessor(0)]; MachineBasicBlock *FBB = FuncInfo.MBBMap[BI->getSuccessor(1)]; BI->getCondition(); // For now, just try the simplest case where it's fed by a compare. if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) { unsigned CondReg = createResultReg(&Mips::GPR32RegClass); if (!emitCmp(CondReg, CI)) return false; BuildMI(*BrBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::BGTZ)) .addReg(CondReg) .addMBB(TBB); finishCondBranch(BI->getParent(), TBB, FBB); return true; } return false; } bool MipsFastISel::selectCmp(const Instruction *I) { const CmpInst *CI = cast<CmpInst>(I); unsigned ResultReg = createResultReg(&Mips::GPR32RegClass); if (!emitCmp(ResultReg, CI)) return false; updateValueMap(I, ResultReg); return true; } // Attempt to fast-select a floating-point extend instruction. bool MipsFastISel::selectFPExt(const Instruction *I) { if (UnsupportedFPMode) return false; Value *Src = I->getOperand(0); EVT SrcVT = TLI.getValueType(DL, Src->getType(), true); EVT DestVT = TLI.getValueType(DL, I->getType(), true); if (SrcVT != MVT::f32 || DestVT != MVT::f64) return false; unsigned SrcReg = getRegForValue(Src); // his must be a 32 bit floating point register class // maybe we should handle this differently if (!SrcReg) return false; unsigned DestReg = createResultReg(&Mips::AFGR64RegClass); emitInst(Mips::CVT_D32_S, DestReg).addReg(SrcReg); updateValueMap(I, DestReg); return true; } bool MipsFastISel::selectSelect(const Instruction *I) { assert(isa<SelectInst>(I) && "Expected a select instruction."); MVT VT; if (!isTypeSupported(I->getType(), VT)) return false; unsigned CondMovOpc; const TargetRegisterClass *RC; if (VT.isInteger() && !VT.isVector() && VT.getSizeInBits() <= 32) { CondMovOpc = Mips::MOVN_I_I; RC = &Mips::GPR32RegClass; } else if (VT == MVT::f32) { CondMovOpc = Mips::MOVN_I_S; RC = &Mips::FGR32RegClass; } else if (VT == MVT::f64) { CondMovOpc = Mips::MOVN_I_D32; RC = &Mips::AFGR64RegClass; } else return false; const SelectInst *SI = cast<SelectInst>(I); const Value *Cond = SI->getCondition(); unsigned Src1Reg = getRegForValue(SI->getTrueValue()); unsigned Src2Reg = getRegForValue(SI->getFalseValue()); unsigned CondReg = getRegForValue(Cond); if (!Src1Reg || !Src2Reg || !CondReg) return false; unsigned ZExtCondReg = createResultReg(&Mips::GPR32RegClass); if (!ZExtCondReg) return false; if (!emitIntExt(MVT::i1, CondReg, MVT::i32, ZExtCondReg, true)) return false; unsigned ResultReg = createResultReg(RC); unsigned TempReg = createResultReg(RC); if (!ResultReg || !TempReg) return false; emitInst(TargetOpcode::COPY, TempReg).addReg(Src2Reg); emitInst(CondMovOpc, ResultReg) .addReg(Src1Reg).addReg(ZExtCondReg).addReg(TempReg); updateValueMap(I, ResultReg); return true; } // Attempt to fast-select a floating-point truncate instruction. bool MipsFastISel::selectFPTrunc(const Instruction *I) { if (UnsupportedFPMode) return false; Value *Src = I->getOperand(0); EVT SrcVT = TLI.getValueType(DL, Src->getType(), true); EVT DestVT = TLI.getValueType(DL, I->getType(), true); if (SrcVT != MVT::f64 || DestVT != MVT::f32) return false; unsigned SrcReg = getRegForValue(Src); if (!SrcReg) return false; unsigned DestReg = createResultReg(&Mips::FGR32RegClass); if (!DestReg) return false; emitInst(Mips::CVT_S_D32, DestReg).addReg(SrcReg); updateValueMap(I, DestReg); return true; } // Attempt to fast-select a floating-point-to-integer conversion. bool MipsFastISel::selectFPToInt(const Instruction *I, bool IsSigned) { if (UnsupportedFPMode) return false; MVT DstVT, SrcVT; if (!IsSigned) return false; // We don't handle this case yet. There is no native // instruction for this but it can be synthesized. Type *DstTy = I->getType(); if (!isTypeLegal(DstTy, DstVT)) return false; if (DstVT != MVT::i32) return false; Value *Src = I->getOperand(0); Type *SrcTy = Src->getType(); if (!isTypeLegal(SrcTy, SrcVT)) return false; if (SrcVT != MVT::f32 && SrcVT != MVT::f64) return false; unsigned SrcReg = getRegForValue(Src); if (SrcReg == 0) return false; // Determine the opcode for the conversion, which takes place // entirely within FPRs. unsigned DestReg = createResultReg(&Mips::GPR32RegClass); unsigned TempReg = createResultReg(&Mips::FGR32RegClass); unsigned Opc = (SrcVT == MVT::f32) ? Mips::TRUNC_W_S : Mips::TRUNC_W_D32; // Generate the convert. emitInst(Opc, TempReg).addReg(SrcReg); emitInst(Mips::MFC1, DestReg).addReg(TempReg); updateValueMap(I, DestReg); return true; } bool MipsFastISel::processCallArgs(CallLoweringInfo &CLI, SmallVectorImpl<MVT> &OutVTs, unsigned &NumBytes) { CallingConv::ID CC = CLI.CallConv; SmallVector<CCValAssign, 16> ArgLocs; CCState CCInfo(CC, false, *FuncInfo.MF, ArgLocs, *Context); CCInfo.AnalyzeCallOperands(OutVTs, CLI.OutFlags, CCAssignFnForCall(CC)); // Get a count of how many bytes are to be pushed on the stack. NumBytes = CCInfo.getNextStackOffset(); // This is the minimum argument area used for A0-A3. if (NumBytes < 16) NumBytes = 16; emitInst(Mips::ADJCALLSTACKDOWN).addImm(16); // Process the args. MVT firstMVT; for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign &VA = ArgLocs[i]; const Value *ArgVal = CLI.OutVals[VA.getValNo()]; MVT ArgVT = OutVTs[VA.getValNo()]; if (i == 0) { firstMVT = ArgVT; if (ArgVT == MVT::f32) { VA.convertToReg(Mips::F12); } else if (ArgVT == MVT::f64) { VA.convertToReg(Mips::D6); } } else if (i == 1) { if ((firstMVT == MVT::f32) || (firstMVT == MVT::f64)) { if (ArgVT == MVT::f32) { VA.convertToReg(Mips::F14); } else if (ArgVT == MVT::f64) { VA.convertToReg(Mips::D7); } } } if (((ArgVT == MVT::i32) || (ArgVT == MVT::f32) || (ArgVT == MVT::i16) || (ArgVT == MVT::i8)) && VA.isMemLoc()) { switch (VA.getLocMemOffset()) { case 0: VA.convertToReg(Mips::A0); break; case 4: VA.convertToReg(Mips::A1); break; case 8: VA.convertToReg(Mips::A2); break; case 12: VA.convertToReg(Mips::A3); break; default: break; } } unsigned ArgReg = getRegForValue(ArgVal); if (!ArgReg) return false; // Handle arg promotion: SExt, ZExt, AExt. switch (VA.getLocInfo()) { case CCValAssign::Full: break; case CCValAssign::AExt: case CCValAssign::SExt: { MVT DestVT = VA.getLocVT(); MVT SrcVT = ArgVT; ArgReg = emitIntExt(SrcVT, ArgReg, DestVT, /*isZExt=*/false); if (!ArgReg) return false; break; } case CCValAssign::ZExt: { MVT DestVT = VA.getLocVT(); MVT SrcVT = ArgVT; ArgReg = emitIntExt(SrcVT, ArgReg, DestVT, /*isZExt=*/true); if (!ArgReg) return false; break; } default: llvm_unreachable("Unknown arg promotion!"); } // Now copy/store arg to correct locations. if (VA.isRegLoc() && !VA.needsCustom()) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), VA.getLocReg()).addReg(ArgReg); CLI.OutRegs.push_back(VA.getLocReg()); } else if (VA.needsCustom()) { llvm_unreachable("Mips does not use custom args."); return false; } else { // // FIXME: This path will currently return false. It was copied // from the AArch64 port and should be essentially fine for Mips too. // The work to finish up this path will be done in a follow-on patch. // assert(VA.isMemLoc() && "Assuming store on stack."); // Don't emit stores for undef values. if (isa<UndefValue>(ArgVal)) continue; // Need to store on the stack. // FIXME: This alignment is incorrect but this path is disabled // for now (will return false). We need to determine the right alignment // based on the normal alignment for the underlying machine type. // unsigned ArgSize = RoundUpToAlignment(ArgVT.getSizeInBits(), 4); unsigned BEAlign = 0; if (ArgSize < 8 && !Subtarget->isLittle()) BEAlign = 8 - ArgSize; Address Addr; Addr.setKind(Address::RegBase); Addr.setReg(Mips::SP); Addr.setOffset(VA.getLocMemOffset() + BEAlign); unsigned Alignment = DL.getABITypeAlignment(ArgVal->getType()); MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand( MachinePointerInfo::getStack(*FuncInfo.MF, Addr.getOffset()), MachineMemOperand::MOStore, ArgVT.getStoreSize(), Alignment); (void)(MMO); // if (!emitStore(ArgVT, ArgReg, Addr, MMO)) return false; // can't store on the stack yet. } } return true; } bool MipsFastISel::finishCall(CallLoweringInfo &CLI, MVT RetVT, unsigned NumBytes) { CallingConv::ID CC = CLI.CallConv; emitInst(Mips::ADJCALLSTACKUP).addImm(16); if (RetVT != MVT::isVoid) { SmallVector<CCValAssign, 16> RVLocs; CCState CCInfo(CC, false, *FuncInfo.MF, RVLocs, *Context); CCInfo.AnalyzeCallResult(RetVT, RetCC_Mips); // Only handle a single return value. if (RVLocs.size() != 1) return false; // Copy all of the result registers out of their specified physreg. MVT CopyVT = RVLocs[0].getValVT(); // Special handling for extended integers. if (RetVT == MVT::i1 || RetVT == MVT::i8 || RetVT == MVT::i16) CopyVT = MVT::i32; unsigned ResultReg = createResultReg(TLI.getRegClassFor(CopyVT)); if (!ResultReg) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), ResultReg).addReg(RVLocs[0].getLocReg()); CLI.InRegs.push_back(RVLocs[0].getLocReg()); CLI.ResultReg = ResultReg; CLI.NumResultRegs = 1; } return true; } bool MipsFastISel::fastLowerCall(CallLoweringInfo &CLI) { if (!TargetSupported) return false; CallingConv::ID CC = CLI.CallConv; bool IsTailCall = CLI.IsTailCall; bool IsVarArg = CLI.IsVarArg; const Value *Callee = CLI.Callee; MCSymbol *Symbol = CLI.Symbol; // Do not handle FastCC. if (CC == CallingConv::Fast) return false; // Allow SelectionDAG isel to handle tail calls. if (IsTailCall) return false; // Let SDISel handle vararg functions. if (IsVarArg) return false; // FIXME: Only handle *simple* calls for now. MVT RetVT; if (CLI.RetTy->isVoidTy()) RetVT = MVT::isVoid; else if (!isTypeSupported(CLI.RetTy, RetVT)) return false; for (auto Flag : CLI.OutFlags) if (Flag.isInReg() || Flag.isSRet() || Flag.isNest() || Flag.isByVal()) return false; // Set up the argument vectors. SmallVector<MVT, 16> OutVTs; OutVTs.reserve(CLI.OutVals.size()); for (auto *Val : CLI.OutVals) { MVT VT; if (!isTypeLegal(Val->getType(), VT) && !(VT == MVT::i1 || VT == MVT::i8 || VT == MVT::i16)) return false; // We don't handle vector parameters yet. if (VT.isVector() || VT.getSizeInBits() > 64) return false; OutVTs.push_back(VT); } Address Addr; if (!computeCallAddress(Callee, Addr)) return false; // Handle the arguments now that we've gotten them. unsigned NumBytes; if (!processCallArgs(CLI, OutVTs, NumBytes)) return false; if (!Addr.getGlobalValue()) return false; // Issue the call. unsigned DestAddress; if (Symbol) DestAddress = materializeExternalCallSym(Symbol); else DestAddress = materializeGV(Addr.getGlobalValue(), MVT::i32); emitInst(TargetOpcode::COPY, Mips::T9).addReg(DestAddress); MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::JALR), Mips::RA).addReg(Mips::T9); // Add implicit physical register uses to the call. for (auto Reg : CLI.OutRegs) MIB.addReg(Reg, RegState::Implicit); // Add a register mask with the call-preserved registers. // Proper defs for return values will be added by setPhysRegsDeadExcept(). MIB.addRegMask(TRI.getCallPreservedMask(*FuncInfo.MF, CC)); CLI.Call = MIB; // Finish off the call including any return values. return finishCall(CLI, RetVT, NumBytes); } bool MipsFastISel::fastLowerIntrinsicCall(const IntrinsicInst *II) { if (!TargetSupported) return false; switch (II->getIntrinsicID()) { default: return false; case Intrinsic::bswap: { Type *RetTy = II->getCalledFunction()->getReturnType(); MVT VT; if (!isTypeSupported(RetTy, VT)) return false; unsigned SrcReg = getRegForValue(II->getOperand(0)); if (SrcReg == 0) return false; unsigned DestReg = createResultReg(&Mips::GPR32RegClass); if (DestReg == 0) return false; if (VT == MVT::i16) { if (Subtarget->hasMips32r2()) { emitInst(Mips::WSBH, DestReg).addReg(SrcReg); updateValueMap(II, DestReg); return true; } else { unsigned TempReg[3]; for (int i = 0; i < 3; i++) { TempReg[i] = createResultReg(&Mips::GPR32RegClass); if (TempReg[i] == 0) return false; } emitInst(Mips::SLL, TempReg[0]).addReg(SrcReg).addImm(8); emitInst(Mips::SRL, TempReg[1]).addReg(SrcReg).addImm(8); emitInst(Mips::OR, TempReg[2]).addReg(TempReg[0]).addReg(TempReg[1]); emitInst(Mips::ANDi, DestReg).addReg(TempReg[2]).addImm(0xFFFF); updateValueMap(II, DestReg); return true; } } else if (VT == MVT::i32) { if (Subtarget->hasMips32r2()) { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::WSBH, TempReg).addReg(SrcReg); emitInst(Mips::ROTR, DestReg).addReg(TempReg).addImm(16); updateValueMap(II, DestReg); return true; } else { unsigned TempReg[8]; for (int i = 0; i < 8; i++) { TempReg[i] = createResultReg(&Mips::GPR32RegClass); if (TempReg[i] == 0) return false; } emitInst(Mips::SRL, TempReg[0]).addReg(SrcReg).addImm(8); emitInst(Mips::SRL, TempReg[1]).addReg(SrcReg).addImm(24); emitInst(Mips::ANDi, TempReg[2]).addReg(TempReg[0]).addImm(0xFF00); emitInst(Mips::OR, TempReg[3]).addReg(TempReg[1]).addReg(TempReg[2]); emitInst(Mips::ANDi, TempReg[4]).addReg(SrcReg).addImm(0xFF00); emitInst(Mips::SLL, TempReg[5]).addReg(TempReg[4]).addImm(8); emitInst(Mips::SLL, TempReg[6]).addReg(SrcReg).addImm(24); emitInst(Mips::OR, TempReg[7]).addReg(TempReg[3]).addReg(TempReg[5]); emitInst(Mips::OR, DestReg).addReg(TempReg[6]).addReg(TempReg[7]); updateValueMap(II, DestReg); return true; } } return false; } case Intrinsic::memcpy: case Intrinsic::memmove: { const auto *MTI = cast<MemTransferInst>(II); // Don't handle volatile. if (MTI->isVolatile()) return false; if (!MTI->getLength()->getType()->isIntegerTy(32)) return false; const char *IntrMemName = isa<MemCpyInst>(II) ? "memcpy" : "memmove"; return lowerCallTo(II, IntrMemName, II->getNumArgOperands() - 2); } case Intrinsic::memset: { const MemSetInst *MSI = cast<MemSetInst>(II); // Don't handle volatile. if (MSI->isVolatile()) return false; if (!MSI->getLength()->getType()->isIntegerTy(32)) return false; return lowerCallTo(II, "memset", II->getNumArgOperands() - 2); } } return false; } bool MipsFastISel::selectRet(const Instruction *I) { const Function &F = *I->getParent()->getParent(); const ReturnInst *Ret = cast<ReturnInst>(I); if (!FuncInfo.CanLowerReturn) return false; // Build a list of return value registers. SmallVector<unsigned, 4> RetRegs; if (Ret->getNumOperands() > 0) { CallingConv::ID CC = F.getCallingConv(); // Do not handle FastCC. if (CC == CallingConv::Fast) return false; SmallVector<ISD::OutputArg, 4> Outs; GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI, DL); // Analyze operands of the call, assigning locations to each operand. SmallVector<CCValAssign, 16> ValLocs; MipsCCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs, I->getContext()); CCAssignFn *RetCC = RetCC_Mips; CCInfo.AnalyzeReturn(Outs, RetCC); // Only handle a single return value for now. if (ValLocs.size() != 1) return false; CCValAssign &VA = ValLocs[0]; const Value *RV = Ret->getOperand(0); // Don't bother handling odd stuff for now. if ((VA.getLocInfo() != CCValAssign::Full) && (VA.getLocInfo() != CCValAssign::BCvt)) return false; // Only handle register returns for now. if (!VA.isRegLoc()) return false; unsigned Reg = getRegForValue(RV); if (Reg == 0) return false; unsigned SrcReg = Reg + VA.getValNo(); unsigned DestReg = VA.getLocReg(); // Avoid a cross-class copy. This is very unlikely. if (!MRI.getRegClass(SrcReg)->contains(DestReg)) return false; EVT RVEVT = TLI.getValueType(DL, RV->getType()); if (!RVEVT.isSimple()) return false; if (RVEVT.isVector()) return false; MVT RVVT = RVEVT.getSimpleVT(); if (RVVT == MVT::f128) return false; MVT DestVT = VA.getValVT(); // Special handling for extended integers. if (RVVT != DestVT) { if (RVVT != MVT::i1 && RVVT != MVT::i8 && RVVT != MVT::i16) return false; if (Outs[0].Flags.isZExt() || Outs[0].Flags.isSExt()) { bool IsZExt = Outs[0].Flags.isZExt(); SrcReg = emitIntExt(RVVT, SrcReg, DestVT, IsZExt); if (SrcReg == 0) return false; } } // Make the copy. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), DestReg).addReg(SrcReg); // Add register to return instruction. RetRegs.push_back(VA.getLocReg()); } MachineInstrBuilder MIB = emitInst(Mips::RetRA); for (unsigned i = 0, e = RetRegs.size(); i != e; ++i) MIB.addReg(RetRegs[i], RegState::Implicit); return true; } bool MipsFastISel::selectTrunc(const Instruction *I) { // The high bits for a type smaller than the register size are assumed to be // undefined. Value *Op = I->getOperand(0); EVT SrcVT, DestVT; SrcVT = TLI.getValueType(DL, Op->getType(), true); DestVT = TLI.getValueType(DL, I->getType(), true); if (SrcVT != MVT::i32 && SrcVT != MVT::i16 && SrcVT != MVT::i8) return false; if (DestVT != MVT::i16 && DestVT != MVT::i8 && DestVT != MVT::i1) return false; unsigned SrcReg = getRegForValue(Op); if (!SrcReg) return false; // Because the high bits are undefined, a truncate doesn't generate // any code. updateValueMap(I, SrcReg); return true; } bool MipsFastISel::selectIntExt(const Instruction *I) { Type *DestTy = I->getType(); Value *Src = I->getOperand(0); Type *SrcTy = Src->getType(); bool isZExt = isa<ZExtInst>(I); unsigned SrcReg = getRegForValue(Src); if (!SrcReg) return false; EVT SrcEVT, DestEVT; SrcEVT = TLI.getValueType(DL, SrcTy, true); DestEVT = TLI.getValueType(DL, DestTy, true); if (!SrcEVT.isSimple()) return false; if (!DestEVT.isSimple()) return false; MVT SrcVT = SrcEVT.getSimpleVT(); MVT DestVT = DestEVT.getSimpleVT(); unsigned ResultReg = createResultReg(&Mips::GPR32RegClass); if (!emitIntExt(SrcVT, SrcReg, DestVT, ResultReg, isZExt)) return false; updateValueMap(I, ResultReg); return true; } bool MipsFastISel::emitIntSExt32r1(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg) { unsigned ShiftAmt; switch (SrcVT.SimpleTy) { default: return false; case MVT::i8: ShiftAmt = 24; break; case MVT::i16: ShiftAmt = 16; break; } unsigned TempReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::SLL, TempReg).addReg(SrcReg).addImm(ShiftAmt); emitInst(Mips::SRA, DestReg).addReg(TempReg).addImm(ShiftAmt); return true; } bool MipsFastISel::emitIntSExt32r2(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg) { switch (SrcVT.SimpleTy) { default: return false; case MVT::i8: emitInst(Mips::SEB, DestReg).addReg(SrcReg); break; case MVT::i16: emitInst(Mips::SEH, DestReg).addReg(SrcReg); break; } return true; } bool MipsFastISel::emitIntSExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg) { if ((DestVT != MVT::i32) && (DestVT != MVT::i16)) return false; if (Subtarget->hasMips32r2()) return emitIntSExt32r2(SrcVT, SrcReg, DestVT, DestReg); return emitIntSExt32r1(SrcVT, SrcReg, DestVT, DestReg); } bool MipsFastISel::emitIntZExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg) { int64_t Imm; switch (SrcVT.SimpleTy) { default: return false; case MVT::i1: Imm = 1; break; case MVT::i8: Imm = 0xff; break; case MVT::i16: Imm = 0xffff; break; } emitInst(Mips::ANDi, DestReg).addReg(SrcReg).addImm(Imm); return true; } bool MipsFastISel::emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, unsigned DestReg, bool IsZExt) { // FastISel does not have plumbing to deal with extensions where the SrcVT or // DestVT are odd things, so test to make sure that they are both types we can // handle (i1/i8/i16/i32 for SrcVT and i8/i16/i32/i64 for DestVT), otherwise // bail out to SelectionDAG. if (((DestVT != MVT::i8) && (DestVT != MVT::i16) && (DestVT != MVT::i32)) || ((SrcVT != MVT::i1) && (SrcVT != MVT::i8) && (SrcVT != MVT::i16))) return false; if (IsZExt) return emitIntZExt(SrcVT, SrcReg, DestVT, DestReg); return emitIntSExt(SrcVT, SrcReg, DestVT, DestReg); } unsigned MipsFastISel::emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT, bool isZExt) { unsigned DestReg = createResultReg(&Mips::GPR32RegClass); bool Success = emitIntExt(SrcVT, SrcReg, DestVT, DestReg, isZExt); return Success ? DestReg : 0; } bool MipsFastISel::selectDivRem(const Instruction *I, unsigned ISDOpcode) { EVT DestEVT = TLI.getValueType(DL, I->getType(), true); if (!DestEVT.isSimple()) return false; MVT DestVT = DestEVT.getSimpleVT(); if (DestVT != MVT::i32) return false; unsigned DivOpc; switch (ISDOpcode) { default: return false; case ISD::SDIV: case ISD::SREM: DivOpc = Mips::SDIV; break; case ISD::UDIV: case ISD::UREM: DivOpc = Mips::UDIV; break; } unsigned Src0Reg = getRegForValue(I->getOperand(0)); unsigned Src1Reg = getRegForValue(I->getOperand(1)); if (!Src0Reg || !Src1Reg) return false; emitInst(DivOpc).addReg(Src0Reg).addReg(Src1Reg); emitInst(Mips::TEQ).addReg(Src1Reg).addReg(Mips::ZERO).addImm(7); unsigned ResultReg = createResultReg(&Mips::GPR32RegClass); if (!ResultReg) return false; unsigned MFOpc = (ISDOpcode == ISD::SREM || ISDOpcode == ISD::UREM) ? Mips::MFHI : Mips::MFLO; emitInst(MFOpc, ResultReg); updateValueMap(I, ResultReg); return true; } bool MipsFastISel::selectShift(const Instruction *I) { MVT RetVT; if (!isTypeSupported(I->getType(), RetVT)) return false; unsigned ResultReg = createResultReg(&Mips::GPR32RegClass); if (!ResultReg) return false; unsigned Opcode = I->getOpcode(); const Value *Op0 = I->getOperand(0); unsigned Op0Reg = getRegForValue(Op0); if (!Op0Reg) return false; // If AShr or LShr, then we need to make sure the operand0 is sign extended. if (Opcode == Instruction::AShr || Opcode == Instruction::LShr) { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); if (!TempReg) return false; MVT Op0MVT = TLI.getValueType(DL, Op0->getType(), true).getSimpleVT(); bool IsZExt = Opcode == Instruction::LShr; if (!emitIntExt(Op0MVT, Op0Reg, MVT::i32, TempReg, IsZExt)) return false; Op0Reg = TempReg; } if (const auto *C = dyn_cast<ConstantInt>(I->getOperand(1))) { uint64_t ShiftVal = C->getZExtValue(); switch (Opcode) { default: llvm_unreachable("Unexpected instruction."); case Instruction::Shl: Opcode = Mips::SLL; break; case Instruction::AShr: Opcode = Mips::SRA; break; case Instruction::LShr: Opcode = Mips::SRL; break; } emitInst(Opcode, ResultReg).addReg(Op0Reg).addImm(ShiftVal); updateValueMap(I, ResultReg); return true; } unsigned Op1Reg = getRegForValue(I->getOperand(1)); if (!Op1Reg) return false; switch (Opcode) { default: llvm_unreachable("Unexpected instruction."); case Instruction::Shl: Opcode = Mips::SLLV; break; case Instruction::AShr: Opcode = Mips::SRAV; break; case Instruction::LShr: Opcode = Mips::SRLV; break; } emitInst(Opcode, ResultReg).addReg(Op0Reg).addReg(Op1Reg); updateValueMap(I, ResultReg); return true; } bool MipsFastISel::fastSelectInstruction(const Instruction *I) { if (!TargetSupported) return false; switch (I->getOpcode()) { default: break; case Instruction::Load: return selectLoad(I); case Instruction::Store: return selectStore(I); case Instruction::SDiv: if (!selectBinaryOp(I, ISD::SDIV)) return selectDivRem(I, ISD::SDIV); return true; case Instruction::UDiv: if (!selectBinaryOp(I, ISD::UDIV)) return selectDivRem(I, ISD::UDIV); return true; case Instruction::SRem: if (!selectBinaryOp(I, ISD::SREM)) return selectDivRem(I, ISD::SREM); return true; case Instruction::URem: if (!selectBinaryOp(I, ISD::UREM)) return selectDivRem(I, ISD::UREM); return true; case Instruction::Shl: case Instruction::LShr: case Instruction::AShr: return selectShift(I); case Instruction::And: case Instruction::Or: case Instruction::Xor: return selectLogicalOp(I); case Instruction::Br: return selectBranch(I); case Instruction::Ret: return selectRet(I); case Instruction::Trunc: return selectTrunc(I); case Instruction::ZExt: case Instruction::SExt: return selectIntExt(I); case Instruction::FPTrunc: return selectFPTrunc(I); case Instruction::FPExt: return selectFPExt(I); case Instruction::FPToSI: return selectFPToInt(I, /*isSigned*/ true); case Instruction::FPToUI: return selectFPToInt(I, /*isSigned*/ false); case Instruction::ICmp: case Instruction::FCmp: return selectCmp(I); case Instruction::Select: return selectSelect(I); } return false; } unsigned MipsFastISel::getRegEnsuringSimpleIntegerWidening(const Value *V, bool IsUnsigned) { unsigned VReg = getRegForValue(V); if (VReg == 0) return 0; MVT VMVT = TLI.getValueType(DL, V->getType(), true).getSimpleVT(); if ((VMVT == MVT::i8) || (VMVT == MVT::i16)) { unsigned TempReg = createResultReg(&Mips::GPR32RegClass); if (!emitIntExt(VMVT, VReg, MVT::i32, TempReg, IsUnsigned)) return 0; VReg = TempReg; } return VReg; } void MipsFastISel::simplifyAddress(Address &Addr) { if (!isInt<16>(Addr.getOffset())) { unsigned TempReg = materialize32BitInt(Addr.getOffset(), &Mips::GPR32RegClass); unsigned DestReg = createResultReg(&Mips::GPR32RegClass); emitInst(Mips::ADDu, DestReg).addReg(TempReg).addReg(Addr.getReg()); Addr.setReg(DestReg); Addr.setOffset(0); } } unsigned MipsFastISel::fastEmitInst_rr(unsigned MachineInstOpcode, const TargetRegisterClass *RC, unsigned Op0, bool Op0IsKill, unsigned Op1, bool Op1IsKill) { // We treat the MUL instruction in a special way because it clobbers // the HI0 & LO0 registers. The TableGen definition of this instruction can // mark these registers only as implicitly defined. As a result, the // register allocator runs out of registers when this instruction is // followed by another instruction that defines the same registers too. // We can fix this by explicitly marking those registers as dead. if (MachineInstOpcode == Mips::MUL) { unsigned ResultReg = createResultReg(RC); const MCInstrDesc &II = TII.get(MachineInstOpcode); Op0 = constrainOperandRegClass(II, Op0, II.getNumDefs()); Op1 = constrainOperandRegClass(II, Op1, II.getNumDefs() + 1); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II, ResultReg) .addReg(Op0, getKillRegState(Op0IsKill)) .addReg(Op1, getKillRegState(Op1IsKill)) .addReg(Mips::HI0, RegState::ImplicitDefine | RegState::Dead) .addReg(Mips::LO0, RegState::ImplicitDefine | RegState::Dead); return ResultReg; } return FastISel::fastEmitInst_rr(MachineInstOpcode, RC, Op0, Op0IsKill, Op1, Op1IsKill); } namespace llvm { FastISel *Mips::createFastISel(FunctionLoweringInfo &funcInfo, const TargetLibraryInfo *libInfo) { return new MipsFastISel(funcInfo, libInfo); } }