//===-- X86FastISel.cpp - X86 FastISel implementation ---------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines the X86-specific support for the FastISel class. Much // of the target-specific code is generated by tablegen in the file // X86GenFastISel.inc, which is #included here. // //===----------------------------------------------------------------------===// #include "X86.h" #include "X86CallingConv.h" #include "X86InstrBuilder.h" #include "X86InstrInfo.h" #include "X86MachineFunctionInfo.h" #include "X86RegisterInfo.h" #include "X86Subtarget.h" #include "X86TargetMachine.h" #include "llvm/Analysis/BranchProbabilityInfo.h" #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/FastISel.h" #include "llvm/CodeGen/FunctionLoweringInfo.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/IR/CallSite.h" #include "llvm/IR/CallingConv.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/GlobalAlias.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Operator.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Target/TargetOptions.h" using namespace llvm; namespace { class X86FastISel final : public FastISel { /// Subtarget - Keep a pointer to the X86Subtarget around so that we can /// make the right decision when generating code for different targets. const X86Subtarget *Subtarget; /// X86ScalarSSEf32, X86ScalarSSEf64 - Select between SSE or x87 /// floating point ops. /// When SSE is available, use it for f32 operations. /// When SSE2 is available, use it for f64 operations. bool X86ScalarSSEf64; bool X86ScalarSSEf32; public: explicit X86FastISel(FunctionLoweringInfo &funcInfo, const TargetLibraryInfo *libInfo) : FastISel(funcInfo, libInfo) { Subtarget = &funcInfo.MF->getSubtarget(); X86ScalarSSEf64 = Subtarget->hasSSE2(); X86ScalarSSEf32 = Subtarget->hasSSE1(); } bool fastSelectInstruction(const Instruction *I) override; /// \brief The specified machine instr operand is a vreg, and that /// vreg is being provided by the specified load instruction. If possible, /// try to fold the load as an operand to the instruction, returning true if /// possible. bool tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo, const LoadInst *LI) override; bool fastLowerArguments() override; bool fastLowerCall(CallLoweringInfo &CLI) override; bool fastLowerIntrinsicCall(const IntrinsicInst *II) override; #include "X86GenFastISel.inc" private: bool X86FastEmitCompare(const Value *LHS, const Value *RHS, EVT VT, DebugLoc DL); bool X86FastEmitLoad(EVT VT, const X86AddressMode &AM, MachineMemOperand *MMO, unsigned &ResultReg, unsigned Alignment = 1); bool X86FastEmitStore(EVT VT, const Value *Val, const X86AddressMode &AM, MachineMemOperand *MMO = nullptr, bool Aligned = false); bool X86FastEmitStore(EVT VT, unsigned ValReg, bool ValIsKill, const X86AddressMode &AM, MachineMemOperand *MMO = nullptr, bool Aligned = false); bool X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT, unsigned Src, EVT SrcVT, unsigned &ResultReg); bool X86SelectAddress(const Value *V, X86AddressMode &AM); bool X86SelectCallAddress(const Value *V, X86AddressMode &AM); bool X86SelectLoad(const Instruction *I); bool X86SelectStore(const Instruction *I); bool X86SelectRet(const Instruction *I); bool X86SelectCmp(const Instruction *I); bool X86SelectZExt(const Instruction *I); bool X86SelectBranch(const Instruction *I); bool X86SelectShift(const Instruction *I); bool X86SelectDivRem(const Instruction *I); bool X86FastEmitCMoveSelect(MVT RetVT, const Instruction *I); bool X86FastEmitSSESelect(MVT RetVT, const Instruction *I); bool X86FastEmitPseudoSelect(MVT RetVT, const Instruction *I); bool X86SelectSelect(const Instruction *I); bool X86SelectTrunc(const Instruction *I); bool X86SelectFPExtOrFPTrunc(const Instruction *I, unsigned Opc, const TargetRegisterClass *RC); bool X86SelectFPExt(const Instruction *I); bool X86SelectFPTrunc(const Instruction *I); bool X86SelectSIToFP(const Instruction *I); const X86InstrInfo *getInstrInfo() const { return Subtarget->getInstrInfo(); } const X86TargetMachine *getTargetMachine() const { return static_cast(&TM); } bool handleConstantAddresses(const Value *V, X86AddressMode &AM); unsigned X86MaterializeInt(const ConstantInt *CI, MVT VT); unsigned X86MaterializeFP(const ConstantFP *CFP, MVT VT); unsigned X86MaterializeGV(const GlobalValue *GV, MVT VT); unsigned fastMaterializeConstant(const Constant *C) override; unsigned fastMaterializeAlloca(const AllocaInst *C) override; unsigned fastMaterializeFloatZero(const ConstantFP *CF) override; /// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is /// computed in an SSE register, not on the X87 floating point stack. bool isScalarFPTypeInSSEReg(EVT VT) const { return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2 (VT == MVT::f32 && X86ScalarSSEf32); // f32 is when SSE1 } bool isTypeLegal(Type *Ty, MVT &VT, bool AllowI1 = false); bool IsMemcpySmall(uint64_t Len); bool TryEmitSmallMemcpy(X86AddressMode DestAM, X86AddressMode SrcAM, uint64_t Len); bool foldX86XALUIntrinsic(X86::CondCode &CC, const Instruction *I, const Value *Cond); }; } // end anonymous namespace. static std::pair getX86ConditionCode(CmpInst::Predicate Predicate) { X86::CondCode CC = X86::COND_INVALID; bool NeedSwap = false; switch (Predicate) { default: break; // Floating-point Predicates case CmpInst::FCMP_UEQ: CC = X86::COND_E; break; case CmpInst::FCMP_OLT: NeedSwap = true; // fall-through case CmpInst::FCMP_OGT: CC = X86::COND_A; break; case CmpInst::FCMP_OLE: NeedSwap = true; // fall-through case CmpInst::FCMP_OGE: CC = X86::COND_AE; break; case CmpInst::FCMP_UGT: NeedSwap = true; // fall-through case CmpInst::FCMP_ULT: CC = X86::COND_B; break; case CmpInst::FCMP_UGE: NeedSwap = true; // fall-through case CmpInst::FCMP_ULE: CC = X86::COND_BE; break; case CmpInst::FCMP_ONE: CC = X86::COND_NE; break; case CmpInst::FCMP_UNO: CC = X86::COND_P; break; case CmpInst::FCMP_ORD: CC = X86::COND_NP; break; case CmpInst::FCMP_OEQ: // fall-through case CmpInst::FCMP_UNE: CC = X86::COND_INVALID; break; // Integer Predicates case CmpInst::ICMP_EQ: CC = X86::COND_E; break; case CmpInst::ICMP_NE: CC = X86::COND_NE; break; case CmpInst::ICMP_UGT: CC = X86::COND_A; break; case CmpInst::ICMP_UGE: CC = X86::COND_AE; break; case CmpInst::ICMP_ULT: CC = X86::COND_B; break; case CmpInst::ICMP_ULE: CC = X86::COND_BE; break; case CmpInst::ICMP_SGT: CC = X86::COND_G; break; case CmpInst::ICMP_SGE: CC = X86::COND_GE; break; case CmpInst::ICMP_SLT: CC = X86::COND_L; break; case CmpInst::ICMP_SLE: CC = X86::COND_LE; break; } return std::make_pair(CC, NeedSwap); } static std::pair getX86SSEConditionCode(CmpInst::Predicate Predicate) { unsigned CC; bool NeedSwap = false; // SSE Condition code mapping: // 0 - EQ // 1 - LT // 2 - LE // 3 - UNORD // 4 - NEQ // 5 - NLT // 6 - NLE // 7 - ORD switch (Predicate) { default: llvm_unreachable("Unexpected predicate"); case CmpInst::FCMP_OEQ: CC = 0; break; case CmpInst::FCMP_OGT: NeedSwap = true; // fall-through case CmpInst::FCMP_OLT: CC = 1; break; case CmpInst::FCMP_OGE: NeedSwap = true; // fall-through case CmpInst::FCMP_OLE: CC = 2; break; case CmpInst::FCMP_UNO: CC = 3; break; case CmpInst::FCMP_UNE: CC = 4; break; case CmpInst::FCMP_ULE: NeedSwap = true; // fall-through case CmpInst::FCMP_UGE: CC = 5; break; case CmpInst::FCMP_ULT: NeedSwap = true; // fall-through case CmpInst::FCMP_UGT: CC = 6; break; case CmpInst::FCMP_ORD: CC = 7; break; case CmpInst::FCMP_UEQ: case CmpInst::FCMP_ONE: CC = 8; break; } return std::make_pair(CC, NeedSwap); } /// \brief Check if it is possible to fold the condition from the XALU intrinsic /// into the user. The condition code will only be updated on success. bool X86FastISel::foldX86XALUIntrinsic(X86::CondCode &CC, const Instruction *I, const Value *Cond) { if (!isa(Cond)) return false; const auto *EV = cast(Cond); if (!isa(EV->getAggregateOperand())) return false; const auto *II = cast(EV->getAggregateOperand()); MVT RetVT; const Function *Callee = II->getCalledFunction(); Type *RetTy = cast(Callee->getReturnType())->getTypeAtIndex(0U); if (!isTypeLegal(RetTy, RetVT)) return false; if (RetVT != MVT::i32 && RetVT != MVT::i64) return false; X86::CondCode TmpCC; switch (II->getIntrinsicID()) { default: return false; case Intrinsic::sadd_with_overflow: case Intrinsic::ssub_with_overflow: case Intrinsic::smul_with_overflow: case Intrinsic::umul_with_overflow: TmpCC = X86::COND_O; break; case Intrinsic::uadd_with_overflow: case Intrinsic::usub_with_overflow: TmpCC = X86::COND_B; break; } // Check if both instructions are in the same basic block. if (II->getParent() != I->getParent()) return false; // Make sure nothing is in the way BasicBlock::const_iterator Start = I; BasicBlock::const_iterator End = II; for (auto Itr = std::prev(Start); Itr != End; --Itr) { // We only expect extractvalue instructions between the intrinsic and the // instruction to be selected. if (!isa(Itr)) return false; // Check that the extractvalue operand comes from the intrinsic. const auto *EVI = cast(Itr); if (EVI->getAggregateOperand() != II) return false; } CC = TmpCC; return true; } bool X86FastISel::isTypeLegal(Type *Ty, MVT &VT, bool AllowI1) { EVT evt = TLI.getValueType(Ty, /*HandleUnknown=*/true); if (evt == MVT::Other || !evt.isSimple()) // Unhandled type. Halt "fast" selection and bail. return false; VT = evt.getSimpleVT(); // For now, require SSE/SSE2 for performing floating-point operations, // since x87 requires additional work. if (VT == MVT::f64 && !X86ScalarSSEf64) return false; if (VT == MVT::f32 && !X86ScalarSSEf32) return false; // Similarly, no f80 support yet. if (VT == MVT::f80) return false; // We only handle legal types. For example, on x86-32 the instruction // selector contains all of the 64-bit instructions from x86-64, // under the assumption that i64 won't be used if the target doesn't // support it. return (AllowI1 && VT == MVT::i1) || TLI.isTypeLegal(VT); } #include "X86GenCallingConv.inc" /// X86FastEmitLoad - Emit a machine instruction to load a value of type VT. /// The address is either pre-computed, i.e. Ptr, or a GlobalAddress, i.e. GV. /// Return true and the result register by reference if it is possible. bool X86FastISel::X86FastEmitLoad(EVT VT, const X86AddressMode &AM, MachineMemOperand *MMO, unsigned &ResultReg, unsigned Alignment) { // Get opcode and regclass of the output for the given load instruction. unsigned Opc = 0; const TargetRegisterClass *RC = nullptr; switch (VT.getSimpleVT().SimpleTy) { default: return false; case MVT::i1: case MVT::i8: Opc = X86::MOV8rm; RC = &X86::GR8RegClass; break; case MVT::i16: Opc = X86::MOV16rm; RC = &X86::GR16RegClass; break; case MVT::i32: Opc = X86::MOV32rm; RC = &X86::GR32RegClass; break; case MVT::i64: // Must be in x86-64 mode. Opc = X86::MOV64rm; RC = &X86::GR64RegClass; break; case MVT::f32: if (X86ScalarSSEf32) { Opc = Subtarget->hasAVX() ? X86::VMOVSSrm : X86::MOVSSrm; RC = &X86::FR32RegClass; } else { Opc = X86::LD_Fp32m; RC = &X86::RFP32RegClass; } break; case MVT::f64: if (X86ScalarSSEf64) { Opc = Subtarget->hasAVX() ? X86::VMOVSDrm : X86::MOVSDrm; RC = &X86::FR64RegClass; } else { Opc = X86::LD_Fp64m; RC = &X86::RFP64RegClass; } break; case MVT::f80: // No f80 support yet. return false; case MVT::v4f32: if (Alignment >= 16) Opc = Subtarget->hasAVX() ? X86::VMOVAPSrm : X86::MOVAPSrm; else Opc = Subtarget->hasAVX() ? X86::VMOVUPSrm : X86::MOVUPSrm; RC = &X86::VR128RegClass; break; case MVT::v2f64: if (Alignment >= 16) Opc = Subtarget->hasAVX() ? X86::VMOVAPDrm : X86::MOVAPDrm; else Opc = Subtarget->hasAVX() ? X86::VMOVUPDrm : X86::MOVUPDrm; RC = &X86::VR128RegClass; break; case MVT::v4i32: case MVT::v2i64: case MVT::v8i16: case MVT::v16i8: if (Alignment >= 16) Opc = Subtarget->hasAVX() ? X86::VMOVDQArm : X86::MOVDQArm; else Opc = Subtarget->hasAVX() ? X86::VMOVDQUrm : X86::MOVDQUrm; RC = &X86::VR128RegClass; break; } ResultReg = createResultReg(RC); MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg); addFullAddress(MIB, AM); if (MMO) MIB->addMemOperand(*FuncInfo.MF, MMO); return true; } /// X86FastEmitStore - Emit a machine instruction to store a value Val of /// type VT. The address is either pre-computed, consisted of a base ptr, Ptr /// and a displacement offset, or a GlobalAddress, /// i.e. V. Return true if it is possible. bool X86FastISel::X86FastEmitStore(EVT VT, unsigned ValReg, bool ValIsKill, const X86AddressMode &AM, MachineMemOperand *MMO, bool Aligned) { // Get opcode and regclass of the output for the given store instruction. unsigned Opc = 0; switch (VT.getSimpleVT().SimpleTy) { case MVT::f80: // No f80 support yet. default: return false; case MVT::i1: { // Mask out all but lowest bit. unsigned AndResult = createResultReg(&X86::GR8RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::AND8ri), AndResult) .addReg(ValReg, getKillRegState(ValIsKill)).addImm(1); ValReg = AndResult; } // FALLTHROUGH, handling i1 as i8. case MVT::i8: Opc = X86::MOV8mr; break; case MVT::i16: Opc = X86::MOV16mr; break; case MVT::i32: Opc = X86::MOV32mr; break; case MVT::i64: Opc = X86::MOV64mr; break; // Must be in x86-64 mode. case MVT::f32: Opc = X86ScalarSSEf32 ? (Subtarget->hasAVX() ? X86::VMOVSSmr : X86::MOVSSmr) : X86::ST_Fp32m; break; case MVT::f64: Opc = X86ScalarSSEf64 ? (Subtarget->hasAVX() ? X86::VMOVSDmr : X86::MOVSDmr) : X86::ST_Fp64m; break; case MVT::v4f32: if (Aligned) Opc = Subtarget->hasAVX() ? X86::VMOVAPSmr : X86::MOVAPSmr; else Opc = Subtarget->hasAVX() ? X86::VMOVUPSmr : X86::MOVUPSmr; break; case MVT::v2f64: if (Aligned) Opc = Subtarget->hasAVX() ? X86::VMOVAPDmr : X86::MOVAPDmr; else Opc = Subtarget->hasAVX() ? X86::VMOVUPDmr : X86::MOVUPDmr; break; case MVT::v4i32: case MVT::v2i64: case MVT::v8i16: case MVT::v16i8: if (Aligned) Opc = Subtarget->hasAVX() ? X86::VMOVDQAmr : X86::MOVDQAmr; else Opc = Subtarget->hasAVX() ? X86::VMOVDQUmr : X86::MOVDQUmr; break; } MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc)); addFullAddress(MIB, AM).addReg(ValReg, getKillRegState(ValIsKill)); if (MMO) MIB->addMemOperand(*FuncInfo.MF, MMO); return true; } bool X86FastISel::X86FastEmitStore(EVT VT, const Value *Val, const X86AddressMode &AM, MachineMemOperand *MMO, bool Aligned) { // Handle 'null' like i32/i64 0. if (isa(Val)) Val = Constant::getNullValue(DL.getIntPtrType(Val->getContext())); // If this is a store of a simple constant, fold the constant into the store. if (const ConstantInt *CI = dyn_cast(Val)) { unsigned Opc = 0; bool Signed = true; switch (VT.getSimpleVT().SimpleTy) { default: break; case MVT::i1: Signed = false; // FALLTHROUGH to handle as i8. case MVT::i8: Opc = X86::MOV8mi; break; case MVT::i16: Opc = X86::MOV16mi; break; case MVT::i32: Opc = X86::MOV32mi; break; case MVT::i64: // Must be a 32-bit sign extended value. if (isInt<32>(CI->getSExtValue())) Opc = X86::MOV64mi32; break; } if (Opc) { MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc)); addFullAddress(MIB, AM).addImm(Signed ? (uint64_t) CI->getSExtValue() : CI->getZExtValue()); if (MMO) MIB->addMemOperand(*FuncInfo.MF, MMO); return true; } } unsigned ValReg = getRegForValue(Val); if (ValReg == 0) return false; bool ValKill = hasTrivialKill(Val); return X86FastEmitStore(VT, ValReg, ValKill, AM, MMO, Aligned); } /// X86FastEmitExtend - Emit a machine instruction to extend a value Src of /// type SrcVT to type DstVT using the specified extension opcode Opc (e.g. /// ISD::SIGN_EXTEND). bool X86FastISel::X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT, unsigned Src, EVT SrcVT, unsigned &ResultReg) { unsigned RR = fastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Opc, Src, /*TODO: Kill=*/false); if (RR == 0) return false; ResultReg = RR; return true; } bool X86FastISel::handleConstantAddresses(const Value *V, X86AddressMode &AM) { // Handle constant address. if (const GlobalValue *GV = dyn_cast(V)) { // Can't handle alternate code models yet. if (TM.getCodeModel() != CodeModel::Small) return false; // Can't handle TLS yet. if (GV->isThreadLocal()) return false; // RIP-relative addresses can't have additional register operands, so if // we've already folded stuff into the addressing mode, just force the // global value into its own register, which we can use as the basereg. if (!Subtarget->isPICStyleRIPRel() || (AM.Base.Reg == 0 && AM.IndexReg == 0)) { // Okay, we've committed to selecting this global. Set up the address. AM.GV = GV; // Allow the subtarget to classify the global. unsigned char GVFlags = Subtarget->ClassifyGlobalReference(GV, TM); // If this reference is relative to the pic base, set it now. if (isGlobalRelativeToPICBase(GVFlags)) { // FIXME: How do we know Base.Reg is free?? AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF); } // Unless the ABI requires an extra load, return a direct reference to // the global. if (!isGlobalStubReference(GVFlags)) { if (Subtarget->isPICStyleRIPRel()) { // Use rip-relative addressing if we can. Above we verified that the // base and index registers are unused. assert(AM.Base.Reg == 0 && AM.IndexReg == 0); AM.Base.Reg = X86::RIP; } AM.GVOpFlags = GVFlags; return true; } // Ok, we need to do a load from a stub. If we've already loaded from // this stub, reuse the loaded pointer, otherwise emit the load now. DenseMap::iterator I = LocalValueMap.find(V); unsigned LoadReg; if (I != LocalValueMap.end() && I->second != 0) { LoadReg = I->second; } else { // Issue load from stub. unsigned Opc = 0; const TargetRegisterClass *RC = nullptr; X86AddressMode StubAM; StubAM.Base.Reg = AM.Base.Reg; StubAM.GV = GV; StubAM.GVOpFlags = GVFlags; // Prepare for inserting code in the local-value area. SavePoint SaveInsertPt = enterLocalValueArea(); if (TLI.getPointerTy() == MVT::i64) { Opc = X86::MOV64rm; RC = &X86::GR64RegClass; if (Subtarget->isPICStyleRIPRel()) StubAM.Base.Reg = X86::RIP; } else { Opc = X86::MOV32rm; RC = &X86::GR32RegClass; } LoadReg = createResultReg(RC); MachineInstrBuilder LoadMI = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), LoadReg); addFullAddress(LoadMI, StubAM); // Ok, back to normal mode. leaveLocalValueArea(SaveInsertPt); // Prevent loading GV stub multiple times in same MBB. LocalValueMap[V] = LoadReg; } // Now construct the final address. Note that the Disp, Scale, // and Index values may already be set here. AM.Base.Reg = LoadReg; AM.GV = nullptr; return true; } } // If all else fails, try to materialize the value in a register. if (!AM.GV || !Subtarget->isPICStyleRIPRel()) { if (AM.Base.Reg == 0) { AM.Base.Reg = getRegForValue(V); return AM.Base.Reg != 0; } if (AM.IndexReg == 0) { assert(AM.Scale == 1 && "Scale with no index!"); AM.IndexReg = getRegForValue(V); return AM.IndexReg != 0; } } return false; } /// X86SelectAddress - Attempt to fill in an address from the given value. /// bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) { SmallVector GEPs; redo_gep: const User *U = nullptr; unsigned Opcode = Instruction::UserOp1; if (const Instruction *I = dyn_cast(V)) { // Don't walk into other basic blocks; it's possible we haven't // visited them yet, so the instructions may not yet be assigned // virtual registers. if (FuncInfo.StaticAllocaMap.count(static_cast(V)) || FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) { Opcode = I->getOpcode(); U = I; } } else if (const ConstantExpr *C = dyn_cast(V)) { Opcode = C->getOpcode(); U = C; } if (PointerType *Ty = dyn_cast(V->getType())) if (Ty->getAddressSpace() > 255) // Fast instruction selection doesn't support the special // address spaces. return false; switch (Opcode) { default: break; case Instruction::BitCast: // Look past bitcasts. return X86SelectAddress(U->getOperand(0), AM); case Instruction::IntToPtr: // Look past no-op inttoptrs. if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy()) return X86SelectAddress(U->getOperand(0), AM); break; case Instruction::PtrToInt: // Look past no-op ptrtoints. if (TLI.getValueType(U->getType()) == TLI.getPointerTy()) return X86SelectAddress(U->getOperand(0), AM); break; case Instruction::Alloca: { // Do static allocas. const AllocaInst *A = cast(V); DenseMap::iterator SI = FuncInfo.StaticAllocaMap.find(A); if (SI != FuncInfo.StaticAllocaMap.end()) { AM.BaseType = X86AddressMode::FrameIndexBase; AM.Base.FrameIndex = SI->second; return true; } break; } case Instruction::Add: { // Adds of constants are common and easy enough. if (const ConstantInt *CI = dyn_cast(U->getOperand(1))) { uint64_t Disp = (int32_t)AM.Disp + (uint64_t)CI->getSExtValue(); // They have to fit in the 32-bit signed displacement field though. if (isInt<32>(Disp)) { AM.Disp = (uint32_t)Disp; return X86SelectAddress(U->getOperand(0), AM); } } break; } case Instruction::GetElementPtr: { X86AddressMode SavedAM = AM; // Pattern-match simple GEPs. uint64_t Disp = (int32_t)AM.Disp; unsigned IndexReg = AM.IndexReg; unsigned Scale = AM.Scale; gep_type_iterator GTI = gep_type_begin(U); // Iterate through the indices, folding what we can. Constants can be // folded, and one dynamic index can be handled, if the scale is supported. 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(*GTI)) { const StructLayout *SL = DL.getStructLayout(STy); Disp += SL->getElementOffset(cast(Op)->getZExtValue()); continue; } // A array/variable index is always of the form i*S where S is the // constant scale size. See if we can push the scale into immediates. uint64_t S = DL.getTypeAllocSize(GTI.getIndexedType()); for (;;) { if (const ConstantInt *CI = dyn_cast(Op)) { // Constant-offset addressing. Disp += CI->getSExtValue() * S; break; } if (canFoldAddIntoGEP(U, Op)) { // A compatible add with a constant operand. Fold the constant. ConstantInt *CI = cast(cast(Op)->getOperand(1)); Disp += CI->getSExtValue() * S; // Iterate on the other operand. Op = cast(Op)->getOperand(0); continue; } if (IndexReg == 0 && (!AM.GV || !Subtarget->isPICStyleRIPRel()) && (S == 1 || S == 2 || S == 4 || S == 8)) { // Scaled-index addressing. Scale = S; IndexReg = getRegForGEPIndex(Op).first; if (IndexReg == 0) return false; break; } // Unsupported. goto unsupported_gep; } } // Check for displacement overflow. if (!isInt<32>(Disp)) break; AM.IndexReg = IndexReg; AM.Scale = Scale; AM.Disp = (uint32_t)Disp; GEPs.push_back(V); if (const GetElementPtrInst *GEP = dyn_cast(U->getOperand(0))) { // Ok, the GEP indices were covered by constant-offset and scaled-index // addressing. Update the address state and move on to examining the base. V = GEP; goto redo_gep; } else if (X86SelectAddress(U->getOperand(0), AM)) { return true; } // If we couldn't merge the gep value into this addr mode, revert back to // our address and just match the value instead of completely failing. AM = SavedAM; for (SmallVectorImpl::reverse_iterator I = GEPs.rbegin(), E = GEPs.rend(); I != E; ++I) if (handleConstantAddresses(*I, AM)) return true; return false; unsupported_gep: // Ok, the GEP indices weren't all covered. break; } } return handleConstantAddresses(V, AM); } /// X86SelectCallAddress - Attempt to fill in an address from the given value. /// bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) { const User *U = nullptr; unsigned Opcode = Instruction::UserOp1; const Instruction *I = dyn_cast(V); // Record if the value is defined in the same basic block. // // This information is crucial to know whether or not folding an // operand is valid. // Indeed, FastISel generates or reuses a virtual register for all // operands of all instructions it selects. Obviously, the definition and // its uses must use the same virtual register otherwise the produced // code is incorrect. // Before instruction selection, FunctionLoweringInfo::set sets the virtual // registers for values that are alive across basic blocks. This ensures // that the values are consistently set between across basic block, even // if different instruction selection mechanisms are used (e.g., a mix of // SDISel and FastISel). // For values local to a basic block, the instruction selection process // generates these virtual registers with whatever method is appropriate // for its needs. In particular, FastISel and SDISel do not share the way // local virtual registers are set. // Therefore, this is impossible (or at least unsafe) to share values // between basic blocks unless they use the same instruction selection // method, which is not guarantee for X86. // Moreover, things like hasOneUse could not be used accurately, if we // allow to reference values across basic blocks whereas they are not // alive across basic blocks initially. bool InMBB = true; if (I) { Opcode = I->getOpcode(); U = I; InMBB = I->getParent() == FuncInfo.MBB->getBasicBlock(); } else if (const ConstantExpr *C = dyn_cast(V)) { Opcode = C->getOpcode(); U = C; } switch (Opcode) { default: break; case Instruction::BitCast: // Look past bitcasts if its operand is in the same BB. if (InMBB) return X86SelectCallAddress(U->getOperand(0), AM); break; case Instruction::IntToPtr: // Look past no-op inttoptrs if its operand is in the same BB. if (InMBB && TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy()) return X86SelectCallAddress(U->getOperand(0), AM); break; case Instruction::PtrToInt: // Look past no-op ptrtoints if its operand is in the same BB. if (InMBB && TLI.getValueType(U->getType()) == TLI.getPointerTy()) return X86SelectCallAddress(U->getOperand(0), AM); break; } // Handle constant address. if (const GlobalValue *GV = dyn_cast(V)) { // Can't handle alternate code models yet. if (TM.getCodeModel() != CodeModel::Small) return false; // RIP-relative addresses can't have additional register operands. if (Subtarget->isPICStyleRIPRel() && (AM.Base.Reg != 0 || AM.IndexReg != 0)) return false; // Can't handle DLL Import. if (GV->hasDLLImportStorageClass()) return false; // Can't handle TLS. if (const GlobalVariable *GVar = dyn_cast(GV)) if (GVar->isThreadLocal()) return false; // Okay, we've committed to selecting this global. Set up the basic address. AM.GV = GV; // No ABI requires an extra load for anything other than DLLImport, which // we rejected above. Return a direct reference to the global. if (Subtarget->isPICStyleRIPRel()) { // Use rip-relative addressing if we can. Above we verified that the // base and index registers are unused. assert(AM.Base.Reg == 0 && AM.IndexReg == 0); AM.Base.Reg = X86::RIP; } else if (Subtarget->isPICStyleStubPIC()) { AM.GVOpFlags = X86II::MO_PIC_BASE_OFFSET; } else if (Subtarget->isPICStyleGOT()) { AM.GVOpFlags = X86II::MO_GOTOFF; } return true; } // If all else fails, try to materialize the value in a register. if (!AM.GV || !Subtarget->isPICStyleRIPRel()) { if (AM.Base.Reg == 0) { AM.Base.Reg = getRegForValue(V); return AM.Base.Reg != 0; } if (AM.IndexReg == 0) { assert(AM.Scale == 1 && "Scale with no index!"); AM.IndexReg = getRegForValue(V); return AM.IndexReg != 0; } } return false; } /// X86SelectStore - Select and emit code to implement store instructions. bool X86FastISel::X86SelectStore(const Instruction *I) { // Atomic stores need special handling. const StoreInst *S = cast(I); if (S->isAtomic()) return false; const Value *Val = S->getValueOperand(); const Value *Ptr = S->getPointerOperand(); MVT VT; if (!isTypeLegal(Val->getType(), VT, /*AllowI1=*/true)) return false; unsigned Alignment = S->getAlignment(); unsigned ABIAlignment = DL.getABITypeAlignment(Val->getType()); if (Alignment == 0) // Ensure that codegen never sees alignment 0 Alignment = ABIAlignment; bool Aligned = Alignment >= ABIAlignment; X86AddressMode AM; if (!X86SelectAddress(Ptr, AM)) return false; return X86FastEmitStore(VT, Val, AM, createMachineMemOperandFor(I), Aligned); } /// X86SelectRet - Select and emit code to implement ret instructions. bool X86FastISel::X86SelectRet(const Instruction *I) { const ReturnInst *Ret = cast(I); const Function &F = *I->getParent()->getParent(); const X86MachineFunctionInfo *X86MFInfo = FuncInfo.MF->getInfo(); if (!FuncInfo.CanLowerReturn) return false; CallingConv::ID CC = F.getCallingConv(); if (CC != CallingConv::C && CC != CallingConv::Fast && CC != CallingConv::X86_FastCall && CC != CallingConv::X86_64_SysV) return false; if (Subtarget->isCallingConvWin64(CC)) return false; // Don't handle popping bytes on return for now. if (X86MFInfo->getBytesToPopOnReturn() != 0) return false; // fastcc with -tailcallopt is intended to provide a guaranteed // tail call optimization. Fastisel doesn't know how to do that. if (CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt) return false; // Let SDISel handle vararg functions. if (F.isVarArg()) return false; // Build a list of return value registers. SmallVector RetRegs; if (Ret->getNumOperands() > 0) { SmallVector Outs; GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI); // Analyze operands of the call, assigning locations to each operand. SmallVector ValLocs; CCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs, I->getContext()); CCInfo.AnalyzeReturn(Outs, RetCC_X86); const Value *RV = Ret->getOperand(0); unsigned Reg = getRegForValue(RV); if (Reg == 0) return false; // Only handle a single return value for now. if (ValLocs.size() != 1) return false; CCValAssign &VA = ValLocs[0]; // Don't bother handling odd stuff for now. if (VA.getLocInfo() != CCValAssign::Full) return false; // Only handle register returns for now. if (!VA.isRegLoc()) return false; // The calling-convention tables for x87 returns don't tell // the whole story. if (VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1) return false; unsigned SrcReg = Reg + VA.getValNo(); EVT SrcVT = TLI.getValueType(RV->getType()); EVT DstVT = VA.getValVT(); // Special handling for extended integers. if (SrcVT != DstVT) { if (SrcVT != MVT::i1 && SrcVT != MVT::i8 && SrcVT != MVT::i16) return false; if (!Outs[0].Flags.isZExt() && !Outs[0].Flags.isSExt()) return false; assert(DstVT == MVT::i32 && "X86 should always ext to i32"); if (SrcVT == MVT::i1) { if (Outs[0].Flags.isSExt()) return false; SrcReg = fastEmitZExtFromI1(MVT::i8, SrcReg, /*TODO: Kill=*/false); SrcVT = MVT::i8; } unsigned Op = Outs[0].Flags.isZExt() ? ISD::ZERO_EXTEND : ISD::SIGN_EXTEND; SrcReg = fastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Op, SrcReg, /*TODO: Kill=*/false); } // Make the copy. unsigned DstReg = VA.getLocReg(); const TargetRegisterClass *SrcRC = MRI.getRegClass(SrcReg); // Avoid a cross-class copy. This is very unlikely. if (!SrcRC->contains(DstReg)) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), DstReg).addReg(SrcReg); // Add register to return instruction. RetRegs.push_back(VA.getLocReg()); } // The x86-64 ABI for returning structs by value requires that we copy // the sret argument into %rax for the return. We saved the argument into // a virtual register in the entry block, so now we copy the value out // and into %rax. We also do the same with %eax for Win32. if (F.hasStructRetAttr() && (Subtarget->is64Bit() || Subtarget->isTargetKnownWindowsMSVC())) { unsigned Reg = X86MFInfo->getSRetReturnReg(); assert(Reg && "SRetReturnReg should have been set in LowerFormalArguments()!"); unsigned RetReg = Subtarget->is64Bit() ? X86::RAX : X86::EAX; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), RetReg).addReg(Reg); RetRegs.push_back(RetReg); } // Now emit the RET. MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Subtarget->is64Bit() ? X86::RETQ : X86::RETL)); for (unsigned i = 0, e = RetRegs.size(); i != e; ++i) MIB.addReg(RetRegs[i], RegState::Implicit); return true; } /// X86SelectLoad - Select and emit code to implement load instructions. /// bool X86FastISel::X86SelectLoad(const Instruction *I) { const LoadInst *LI = cast(I); // Atomic loads need special handling. if (LI->isAtomic()) return false; MVT VT; if (!isTypeLegal(LI->getType(), VT, /*AllowI1=*/true)) return false; const Value *Ptr = LI->getPointerOperand(); X86AddressMode AM; if (!X86SelectAddress(Ptr, AM)) return false; unsigned Alignment = LI->getAlignment(); unsigned ABIAlignment = DL.getABITypeAlignment(LI->getType()); if (Alignment == 0) // Ensure that codegen never sees alignment 0 Alignment = ABIAlignment; unsigned ResultReg = 0; if (!X86FastEmitLoad(VT, AM, createMachineMemOperandFor(LI), ResultReg, Alignment)) return false; updateValueMap(I, ResultReg); return true; } static unsigned X86ChooseCmpOpcode(EVT VT, const X86Subtarget *Subtarget) { bool HasAVX = Subtarget->hasAVX(); bool X86ScalarSSEf32 = Subtarget->hasSSE1(); bool X86ScalarSSEf64 = Subtarget->hasSSE2(); switch (VT.getSimpleVT().SimpleTy) { default: return 0; case MVT::i8: return X86::CMP8rr; case MVT::i16: return X86::CMP16rr; case MVT::i32: return X86::CMP32rr; case MVT::i64: return X86::CMP64rr; case MVT::f32: return X86ScalarSSEf32 ? (HasAVX ? X86::VUCOMISSrr : X86::UCOMISSrr) : 0; case MVT::f64: return X86ScalarSSEf64 ? (HasAVX ? X86::VUCOMISDrr : X86::UCOMISDrr) : 0; } } /// If we have a comparison with RHS as the RHS of the comparison, return an /// opcode that works for the compare (e.g. CMP32ri) otherwise return 0. static unsigned X86ChooseCmpImmediateOpcode(EVT VT, const ConstantInt *RHSC) { int64_t Val = RHSC->getSExtValue(); switch (VT.getSimpleVT().SimpleTy) { // Otherwise, we can't fold the immediate into this comparison. default: return 0; case MVT::i8: return X86::CMP8ri; case MVT::i16: if (isInt<8>(Val)) return X86::CMP16ri8; return X86::CMP16ri; case MVT::i32: if (isInt<8>(Val)) return X86::CMP32ri8; return X86::CMP32ri; case MVT::i64: if (isInt<8>(Val)) return X86::CMP64ri8; // 64-bit comparisons are only valid if the immediate fits in a 32-bit sext // field. if (isInt<32>(Val)) return X86::CMP64ri32; return 0; } } bool X86FastISel::X86FastEmitCompare(const Value *Op0, const Value *Op1, EVT VT, DebugLoc CurDbgLoc) { unsigned Op0Reg = getRegForValue(Op0); if (Op0Reg == 0) return false; // Handle 'null' like i32/i64 0. if (isa(Op1)) Op1 = Constant::getNullValue(DL.getIntPtrType(Op0->getContext())); // We have two options: compare with register or immediate. If the RHS of // the compare is an immediate that we can fold into this compare, use // CMPri, otherwise use CMPrr. if (const ConstantInt *Op1C = dyn_cast(Op1)) { if (unsigned CompareImmOpc = X86ChooseCmpImmediateOpcode(VT, Op1C)) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, CurDbgLoc, TII.get(CompareImmOpc)) .addReg(Op0Reg) .addImm(Op1C->getSExtValue()); return true; } } unsigned CompareOpc = X86ChooseCmpOpcode(VT, Subtarget); if (CompareOpc == 0) return false; unsigned Op1Reg = getRegForValue(Op1); if (Op1Reg == 0) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, CurDbgLoc, TII.get(CompareOpc)) .addReg(Op0Reg) .addReg(Op1Reg); return true; } bool X86FastISel::X86SelectCmp(const Instruction *I) { const CmpInst *CI = cast(I); MVT VT; if (!isTypeLegal(I->getOperand(0)->getType(), VT)) return false; // Try to optimize or fold the cmp. CmpInst::Predicate Predicate = optimizeCmpPredicate(CI); unsigned ResultReg = 0; switch (Predicate) { default: break; case CmpInst::FCMP_FALSE: { ResultReg = createResultReg(&X86::GR32RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV32r0), ResultReg); ResultReg = fastEmitInst_extractsubreg(MVT::i8, ResultReg, /*Kill=*/true, X86::sub_8bit); if (!ResultReg) return false; break; } case CmpInst::FCMP_TRUE: { ResultReg = createResultReg(&X86::GR8RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV8ri), ResultReg).addImm(1); break; } } if (ResultReg) { updateValueMap(I, ResultReg); return true; } const Value *LHS = CI->getOperand(0); const Value *RHS = CI->getOperand(1); // The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, 0.0. // We don't have to materialize a zero constant for this case and can just use // %x again on the RHS. if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) { const auto *RHSC = dyn_cast(RHS); if (RHSC && RHSC->isNullValue()) RHS = LHS; } // FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction. static unsigned SETFOpcTable[2][3] = { { X86::SETEr, X86::SETNPr, X86::AND8rr }, { X86::SETNEr, X86::SETPr, X86::OR8rr } }; unsigned *SETFOpc = nullptr; switch (Predicate) { default: break; case CmpInst::FCMP_OEQ: SETFOpc = &SETFOpcTable[0][0]; break; case CmpInst::FCMP_UNE: SETFOpc = &SETFOpcTable[1][0]; break; } ResultReg = createResultReg(&X86::GR8RegClass); if (SETFOpc) { if (!X86FastEmitCompare(LHS, RHS, VT, I->getDebugLoc())) return false; unsigned FlagReg1 = createResultReg(&X86::GR8RegClass); unsigned FlagReg2 = createResultReg(&X86::GR8RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[0]), FlagReg1); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[1]), FlagReg2); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[2]), ResultReg).addReg(FlagReg1).addReg(FlagReg2); updateValueMap(I, ResultReg); return true; } X86::CondCode CC; bool SwapArgs; std::tie(CC, SwapArgs) = getX86ConditionCode(Predicate); assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code."); unsigned Opc = X86::getSETFromCond(CC); if (SwapArgs) std::swap(LHS, RHS); // Emit a compare of LHS/RHS. if (!X86FastEmitCompare(LHS, RHS, VT, I->getDebugLoc())) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg); updateValueMap(I, ResultReg); return true; } bool X86FastISel::X86SelectZExt(const Instruction *I) { EVT DstVT = TLI.getValueType(I->getType()); if (!TLI.isTypeLegal(DstVT)) return false; unsigned ResultReg = getRegForValue(I->getOperand(0)); if (ResultReg == 0) return false; // Handle zero-extension from i1 to i8, which is common. MVT SrcVT = TLI.getSimpleValueType(I->getOperand(0)->getType()); if (SrcVT.SimpleTy == MVT::i1) { // Set the high bits to zero. ResultReg = fastEmitZExtFromI1(MVT::i8, ResultReg, /*TODO: Kill=*/false); SrcVT = MVT::i8; if (ResultReg == 0) return false; } if (DstVT == MVT::i64) { // Handle extension to 64-bits via sub-register shenanigans. unsigned MovInst; switch (SrcVT.SimpleTy) { case MVT::i8: MovInst = X86::MOVZX32rr8; break; case MVT::i16: MovInst = X86::MOVZX32rr16; break; case MVT::i32: MovInst = X86::MOV32rr; break; default: llvm_unreachable("Unexpected zext to i64 source type"); } unsigned Result32 = createResultReg(&X86::GR32RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(MovInst), Result32) .addReg(ResultReg); ResultReg = createResultReg(&X86::GR64RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::SUBREG_TO_REG), ResultReg) .addImm(0).addReg(Result32).addImm(X86::sub_32bit); } else if (DstVT != MVT::i8) { ResultReg = fastEmit_r(MVT::i8, DstVT.getSimpleVT(), ISD::ZERO_EXTEND, ResultReg, /*Kill=*/true); if (ResultReg == 0) return false; } updateValueMap(I, ResultReg); return true; } bool X86FastISel::X86SelectBranch(const Instruction *I) { // Unconditional branches are selected by tablegen-generated code. // Handle a conditional branch. const BranchInst *BI = cast(I); MachineBasicBlock *TrueMBB = FuncInfo.MBBMap[BI->getSuccessor(0)]; MachineBasicBlock *FalseMBB = FuncInfo.MBBMap[BI->getSuccessor(1)]; // Fold the common case of a conditional branch with a comparison // in the same block (values defined on other blocks may not have // initialized registers). X86::CondCode CC; if (const CmpInst *CI = dyn_cast(BI->getCondition())) { if (CI->hasOneUse() && CI->getParent() == I->getParent()) { EVT VT = TLI.getValueType(CI->getOperand(0)->getType()); // Try to optimize or fold the cmp. CmpInst::Predicate Predicate = optimizeCmpPredicate(CI); switch (Predicate) { default: break; case CmpInst::FCMP_FALSE: fastEmitBranch(FalseMBB, DbgLoc); return true; case CmpInst::FCMP_TRUE: fastEmitBranch(TrueMBB, DbgLoc); return true; } const Value *CmpLHS = CI->getOperand(0); const Value *CmpRHS = CI->getOperand(1); // The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, // 0.0. // We don't have to materialize a zero constant for this case and can just // use %x again on the RHS. if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) { const auto *CmpRHSC = dyn_cast(CmpRHS); if (CmpRHSC && CmpRHSC->isNullValue()) CmpRHS = CmpLHS; } // Try to take advantage of fallthrough opportunities. if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) { std::swap(TrueMBB, FalseMBB); Predicate = CmpInst::getInversePredicate(Predicate); } // FCMP_OEQ and FCMP_UNE cannot be expressed with a single flag/condition // code check. Instead two branch instructions are required to check all // the flags. First we change the predicate to a supported condition code, // which will be the first branch. Later one we will emit the second // branch. bool NeedExtraBranch = false; switch (Predicate) { default: break; case CmpInst::FCMP_OEQ: std::swap(TrueMBB, FalseMBB); // fall-through case CmpInst::FCMP_UNE: NeedExtraBranch = true; Predicate = CmpInst::FCMP_ONE; break; } bool SwapArgs; unsigned BranchOpc; std::tie(CC, SwapArgs) = getX86ConditionCode(Predicate); assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code."); BranchOpc = X86::GetCondBranchFromCond(CC); if (SwapArgs) std::swap(CmpLHS, CmpRHS); // Emit a compare of the LHS and RHS, setting the flags. if (!X86FastEmitCompare(CmpLHS, CmpRHS, VT, CI->getDebugLoc())) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(BranchOpc)) .addMBB(TrueMBB); // X86 requires a second branch to handle UNE (and OEQ, which is mapped // to UNE above). if (NeedExtraBranch) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JP_1)) .addMBB(TrueMBB); } // Obtain the branch weight and add the TrueBB to the successor list. uint32_t BranchWeight = 0; if (FuncInfo.BPI) BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), TrueMBB->getBasicBlock()); FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); // Emits an unconditional branch to the FalseBB, obtains the branch // weight, and adds it to the successor list. fastEmitBranch(FalseMBB, DbgLoc); return true; } } else if (TruncInst *TI = dyn_cast(BI->getCondition())) { // Handle things like "%cond = trunc i32 %X to i1 / br i1 %cond", which // typically happen for _Bool and C++ bools. MVT SourceVT; if (TI->hasOneUse() && TI->getParent() == I->getParent() && isTypeLegal(TI->getOperand(0)->getType(), SourceVT)) { unsigned TestOpc = 0; switch (SourceVT.SimpleTy) { default: break; case MVT::i8: TestOpc = X86::TEST8ri; break; case MVT::i16: TestOpc = X86::TEST16ri; break; case MVT::i32: TestOpc = X86::TEST32ri; break; case MVT::i64: TestOpc = X86::TEST64ri32; break; } if (TestOpc) { unsigned OpReg = getRegForValue(TI->getOperand(0)); if (OpReg == 0) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TestOpc)) .addReg(OpReg).addImm(1); unsigned JmpOpc = X86::JNE_1; if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) { std::swap(TrueMBB, FalseMBB); JmpOpc = X86::JE_1; } BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(JmpOpc)) .addMBB(TrueMBB); fastEmitBranch(FalseMBB, DbgLoc); uint32_t BranchWeight = 0; if (FuncInfo.BPI) BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), TrueMBB->getBasicBlock()); FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); return true; } } } else if (foldX86XALUIntrinsic(CC, BI, BI->getCondition())) { // Fake request the condition, otherwise the intrinsic might be completely // optimized away. unsigned TmpReg = getRegForValue(BI->getCondition()); if (TmpReg == 0) return false; unsigned BranchOpc = X86::GetCondBranchFromCond(CC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(BranchOpc)) .addMBB(TrueMBB); fastEmitBranch(FalseMBB, DbgLoc); uint32_t BranchWeight = 0; if (FuncInfo.BPI) BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), TrueMBB->getBasicBlock()); FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); return true; } // Otherwise do a clumsy setcc and re-test it. // Note that i1 essentially gets ANY_EXTEND'ed to i8 where it isn't used // in an explicit cast, so make sure to handle that correctly. unsigned OpReg = getRegForValue(BI->getCondition()); if (OpReg == 0) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri)) .addReg(OpReg).addImm(1); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JNE_1)) .addMBB(TrueMBB); fastEmitBranch(FalseMBB, DbgLoc); uint32_t BranchWeight = 0; if (FuncInfo.BPI) BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), TrueMBB->getBasicBlock()); FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); return true; } bool X86FastISel::X86SelectShift(const Instruction *I) { unsigned CReg = 0, OpReg = 0; const TargetRegisterClass *RC = nullptr; if (I->getType()->isIntegerTy(8)) { CReg = X86::CL; RC = &X86::GR8RegClass; switch (I->getOpcode()) { case Instruction::LShr: OpReg = X86::SHR8rCL; break; case Instruction::AShr: OpReg = X86::SAR8rCL; break; case Instruction::Shl: OpReg = X86::SHL8rCL; break; default: return false; } } else if (I->getType()->isIntegerTy(16)) { CReg = X86::CX; RC = &X86::GR16RegClass; switch (I->getOpcode()) { case Instruction::LShr: OpReg = X86::SHR16rCL; break; case Instruction::AShr: OpReg = X86::SAR16rCL; break; case Instruction::Shl: OpReg = X86::SHL16rCL; break; default: return false; } } else if (I->getType()->isIntegerTy(32)) { CReg = X86::ECX; RC = &X86::GR32RegClass; switch (I->getOpcode()) { case Instruction::LShr: OpReg = X86::SHR32rCL; break; case Instruction::AShr: OpReg = X86::SAR32rCL; break; case Instruction::Shl: OpReg = X86::SHL32rCL; break; default: return false; } } else if (I->getType()->isIntegerTy(64)) { CReg = X86::RCX; RC = &X86::GR64RegClass; switch (I->getOpcode()) { case Instruction::LShr: OpReg = X86::SHR64rCL; break; case Instruction::AShr: OpReg = X86::SAR64rCL; break; case Instruction::Shl: OpReg = X86::SHL64rCL; break; default: return false; } } else { return false; } MVT VT; if (!isTypeLegal(I->getType(), VT)) return false; unsigned Op0Reg = getRegForValue(I->getOperand(0)); if (Op0Reg == 0) return false; unsigned Op1Reg = getRegForValue(I->getOperand(1)); if (Op1Reg == 0) return false; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), CReg).addReg(Op1Reg); // The shift instruction uses X86::CL. If we defined a super-register // of X86::CL, emit a subreg KILL to precisely describe what we're doing here. if (CReg != X86::CL) BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::KILL), X86::CL) .addReg(CReg, RegState::Kill); unsigned ResultReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(OpReg), ResultReg) .addReg(Op0Reg); updateValueMap(I, ResultReg); return true; } bool X86FastISel::X86SelectDivRem(const Instruction *I) { const static unsigned NumTypes = 4; // i8, i16, i32, i64 const static unsigned NumOps = 4; // SDiv, SRem, UDiv, URem const static bool S = true; // IsSigned const static bool U = false; // !IsSigned const static unsigned Copy = TargetOpcode::COPY; // For the X86 DIV/IDIV instruction, in most cases the dividend // (numerator) must be in a specific register pair highreg:lowreg, // producing the quotient in lowreg and the remainder in highreg. // For most data types, to set up the instruction, the dividend is // copied into lowreg, and lowreg is sign-extended or zero-extended // into highreg. The exception is i8, where the dividend is defined // as a single register rather than a register pair, and we // therefore directly sign-extend or zero-extend the dividend into // lowreg, instead of copying, and ignore the highreg. const static struct DivRemEntry { // The following portion depends only on the data type. const TargetRegisterClass *RC; unsigned LowInReg; // low part of the register pair unsigned HighInReg; // high part of the register pair // The following portion depends on both the data type and the operation. struct DivRemResult { unsigned OpDivRem; // The specific DIV/IDIV opcode to use. unsigned OpSignExtend; // Opcode for sign-extending lowreg into // highreg, or copying a zero into highreg. unsigned OpCopy; // Opcode for copying dividend into lowreg, or // zero/sign-extending into lowreg for i8. unsigned DivRemResultReg; // Register containing the desired result. bool IsOpSigned; // Whether to use signed or unsigned form. } ResultTable[NumOps]; } OpTable[NumTypes] = { { &X86::GR8RegClass, X86::AX, 0, { { X86::IDIV8r, 0, X86::MOVSX16rr8, X86::AL, S }, // SDiv { X86::IDIV8r, 0, X86::MOVSX16rr8, X86::AH, S }, // SRem { X86::DIV8r, 0, X86::MOVZX16rr8, X86::AL, U }, // UDiv { X86::DIV8r, 0, X86::MOVZX16rr8, X86::AH, U }, // URem } }, // i8 { &X86::GR16RegClass, X86::AX, X86::DX, { { X86::IDIV16r, X86::CWD, Copy, X86::AX, S }, // SDiv { X86::IDIV16r, X86::CWD, Copy, X86::DX, S }, // SRem { X86::DIV16r, X86::MOV32r0, Copy, X86::AX, U }, // UDiv { X86::DIV16r, X86::MOV32r0, Copy, X86::DX, U }, // URem } }, // i16 { &X86::GR32RegClass, X86::EAX, X86::EDX, { { X86::IDIV32r, X86::CDQ, Copy, X86::EAX, S }, // SDiv { X86::IDIV32r, X86::CDQ, Copy, X86::EDX, S }, // SRem { X86::DIV32r, X86::MOV32r0, Copy, X86::EAX, U }, // UDiv { X86::DIV32r, X86::MOV32r0, Copy, X86::EDX, U }, // URem } }, // i32 { &X86::GR64RegClass, X86::RAX, X86::RDX, { { X86::IDIV64r, X86::CQO, Copy, X86::RAX, S }, // SDiv { X86::IDIV64r, X86::CQO, Copy, X86::RDX, S }, // SRem { X86::DIV64r, X86::MOV32r0, Copy, X86::RAX, U }, // UDiv { X86::DIV64r, X86::MOV32r0, Copy, X86::RDX, U }, // URem } }, // i64 }; MVT VT; if (!isTypeLegal(I->getType(), VT)) return false; unsigned TypeIndex, OpIndex; switch (VT.SimpleTy) { default: return false; case MVT::i8: TypeIndex = 0; break; case MVT::i16: TypeIndex = 1; break; case MVT::i32: TypeIndex = 2; break; case MVT::i64: TypeIndex = 3; if (!Subtarget->is64Bit()) return false; break; } switch (I->getOpcode()) { default: llvm_unreachable("Unexpected div/rem opcode"); case Instruction::SDiv: OpIndex = 0; break; case Instruction::SRem: OpIndex = 1; break; case Instruction::UDiv: OpIndex = 2; break; case Instruction::URem: OpIndex = 3; break; } const DivRemEntry &TypeEntry = OpTable[TypeIndex]; const DivRemEntry::DivRemResult &OpEntry = TypeEntry.ResultTable[OpIndex]; unsigned Op0Reg = getRegForValue(I->getOperand(0)); if (Op0Reg == 0) return false; unsigned Op1Reg = getRegForValue(I->getOperand(1)); if (Op1Reg == 0) return false; // Move op0 into low-order input register. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(OpEntry.OpCopy), TypeEntry.LowInReg).addReg(Op0Reg); // Zero-extend or sign-extend into high-order input register. if (OpEntry.OpSignExtend) { if (OpEntry.IsOpSigned) BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(OpEntry.OpSignExtend)); else { unsigned Zero32 = createResultReg(&X86::GR32RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV32r0), Zero32); // Copy the zero into the appropriate sub/super/identical physical // register. Unfortunately the operations needed are not uniform enough // to fit neatly into the table above. if (VT.SimpleTy == MVT::i16) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Copy), TypeEntry.HighInReg) .addReg(Zero32, 0, X86::sub_16bit); } else if (VT.SimpleTy == MVT::i32) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Copy), TypeEntry.HighInReg) .addReg(Zero32); } else if (VT.SimpleTy == MVT::i64) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::SUBREG_TO_REG), TypeEntry.HighInReg) .addImm(0).addReg(Zero32).addImm(X86::sub_32bit); } } } // Generate the DIV/IDIV instruction. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(OpEntry.OpDivRem)).addReg(Op1Reg); // For i8 remainder, we can't reference AH directly, as we'll end // up with bogus copies like %R9B = COPY %AH. Reference AX // instead to prevent AH references in a REX instruction. // // The current assumption of the fast register allocator is that isel // won't generate explicit references to the GPR8_NOREX registers. If // the allocator and/or the backend get enhanced to be more robust in // that regard, this can be, and should be, removed. unsigned ResultReg = 0; if ((I->getOpcode() == Instruction::SRem || I->getOpcode() == Instruction::URem) && OpEntry.DivRemResultReg == X86::AH && Subtarget->is64Bit()) { unsigned SourceSuperReg = createResultReg(&X86::GR16RegClass); unsigned ResultSuperReg = createResultReg(&X86::GR16RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Copy), SourceSuperReg).addReg(X86::AX); // Shift AX right by 8 bits instead of using AH. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SHR16ri), ResultSuperReg).addReg(SourceSuperReg).addImm(8); // Now reference the 8-bit subreg of the result. ResultReg = fastEmitInst_extractsubreg(MVT::i8, ResultSuperReg, /*Kill=*/true, X86::sub_8bit); } // Copy the result out of the physreg if we haven't already. if (!ResultReg) { ResultReg = createResultReg(TypeEntry.RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Copy), ResultReg) .addReg(OpEntry.DivRemResultReg); } updateValueMap(I, ResultReg); return true; } /// \brief Emit a conditional move instruction (if the are supported) to lower /// the select. bool X86FastISel::X86FastEmitCMoveSelect(MVT RetVT, const Instruction *I) { // Check if the subtarget supports these instructions. if (!Subtarget->hasCMov()) return false; // FIXME: Add support for i8. if (RetVT < MVT::i16 || RetVT > MVT::i64) return false; const Value *Cond = I->getOperand(0); const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT); bool NeedTest = true; X86::CondCode CC = X86::COND_NE; // Optimize conditions coming from a compare if both instructions are in the // same basic block (values defined in other basic blocks may not have // initialized registers). const auto *CI = dyn_cast(Cond); if (CI && (CI->getParent() == I->getParent())) { CmpInst::Predicate Predicate = optimizeCmpPredicate(CI); // FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction. static unsigned SETFOpcTable[2][3] = { { X86::SETNPr, X86::SETEr , X86::TEST8rr }, { X86::SETPr, X86::SETNEr, X86::OR8rr } }; unsigned *SETFOpc = nullptr; switch (Predicate) { default: break; case CmpInst::FCMP_OEQ: SETFOpc = &SETFOpcTable[0][0]; Predicate = CmpInst::ICMP_NE; break; case CmpInst::FCMP_UNE: SETFOpc = &SETFOpcTable[1][0]; Predicate = CmpInst::ICMP_NE; break; } bool NeedSwap; std::tie(CC, NeedSwap) = getX86ConditionCode(Predicate); assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code."); const Value *CmpLHS = CI->getOperand(0); const Value *CmpRHS = CI->getOperand(1); if (NeedSwap) std::swap(CmpLHS, CmpRHS); EVT CmpVT = TLI.getValueType(CmpLHS->getType()); // Emit a compare of the LHS and RHS, setting the flags. if (!X86FastEmitCompare(CmpLHS, CmpRHS, CmpVT, CI->getDebugLoc())) return false; if (SETFOpc) { unsigned FlagReg1 = createResultReg(&X86::GR8RegClass); unsigned FlagReg2 = createResultReg(&X86::GR8RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[0]), FlagReg1); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[1]), FlagReg2); auto const &II = TII.get(SETFOpc[2]); if (II.getNumDefs()) { unsigned TmpReg = createResultReg(&X86::GR8RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II, TmpReg) .addReg(FlagReg2).addReg(FlagReg1); } else { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II) .addReg(FlagReg2).addReg(FlagReg1); } } NeedTest = false; } else if (foldX86XALUIntrinsic(CC, I, Cond)) { // Fake request the condition, otherwise the intrinsic might be completely // optimized away. unsigned TmpReg = getRegForValue(Cond); if (TmpReg == 0) return false; NeedTest = false; } if (NeedTest) { // Selects operate on i1, however, CondReg is 8 bits width and may contain // garbage. Indeed, only the less significant bit is supposed to be // accurate. If we read more than the lsb, we may see non-zero values // whereas lsb is zero. Therefore, we have to truncate Op0Reg to i1 for // the select. This is achieved by performing TEST against 1. unsigned CondReg = getRegForValue(Cond); if (CondReg == 0) return false; bool CondIsKill = hasTrivialKill(Cond); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri)) .addReg(CondReg, getKillRegState(CondIsKill)).addImm(1); } const Value *LHS = I->getOperand(1); const Value *RHS = I->getOperand(2); unsigned RHSReg = getRegForValue(RHS); bool RHSIsKill = hasTrivialKill(RHS); unsigned LHSReg = getRegForValue(LHS); bool LHSIsKill = hasTrivialKill(LHS); if (!LHSReg || !RHSReg) return false; unsigned Opc = X86::getCMovFromCond(CC, RC->getSize()); unsigned ResultReg = fastEmitInst_rr(Opc, RC, RHSReg, RHSIsKill, LHSReg, LHSIsKill); updateValueMap(I, ResultReg); return true; } /// \brief Emit SSE or AVX instructions to lower the select. /// /// Try to use SSE1/SSE2 instructions to simulate a select without branches. /// This lowers fp selects into a CMP/AND/ANDN/OR sequence when the necessary /// SSE instructions are available. If AVX is available, try to use a VBLENDV. bool X86FastISel::X86FastEmitSSESelect(MVT RetVT, const Instruction *I) { // Optimize conditions coming from a compare if both instructions are in the // same basic block (values defined in other basic blocks may not have // initialized registers). const auto *CI = dyn_cast(I->getOperand(0)); if (!CI || (CI->getParent() != I->getParent())) return false; if (I->getType() != CI->getOperand(0)->getType() || !((Subtarget->hasSSE1() && RetVT == MVT::f32) || (Subtarget->hasSSE2() && RetVT == MVT::f64))) return false; const Value *CmpLHS = CI->getOperand(0); const Value *CmpRHS = CI->getOperand(1); CmpInst::Predicate Predicate = optimizeCmpPredicate(CI); // The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, 0.0. // We don't have to materialize a zero constant for this case and can just use // %x again on the RHS. if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) { const auto *CmpRHSC = dyn_cast(CmpRHS); if (CmpRHSC && CmpRHSC->isNullValue()) CmpRHS = CmpLHS; } unsigned CC; bool NeedSwap; std::tie(CC, NeedSwap) = getX86SSEConditionCode(Predicate); if (CC > 7) return false; if (NeedSwap) std::swap(CmpLHS, CmpRHS); // Choose the SSE instruction sequence based on data type (float or double). static unsigned OpcTable[2][4] = { { X86::CMPSSrr, X86::FsANDPSrr, X86::FsANDNPSrr, X86::FsORPSrr }, { X86::CMPSDrr, X86::FsANDPDrr, X86::FsANDNPDrr, X86::FsORPDrr } }; unsigned *Opc = nullptr; switch (RetVT.SimpleTy) { default: return false; case MVT::f32: Opc = &OpcTable[0][0]; break; case MVT::f64: Opc = &OpcTable[1][0]; break; } const Value *LHS = I->getOperand(1); const Value *RHS = I->getOperand(2); unsigned LHSReg = getRegForValue(LHS); bool LHSIsKill = hasTrivialKill(LHS); unsigned RHSReg = getRegForValue(RHS); bool RHSIsKill = hasTrivialKill(RHS); unsigned CmpLHSReg = getRegForValue(CmpLHS); bool CmpLHSIsKill = hasTrivialKill(CmpLHS); unsigned CmpRHSReg = getRegForValue(CmpRHS); bool CmpRHSIsKill = hasTrivialKill(CmpRHS); if (!LHSReg || !RHSReg || !CmpLHS || !CmpRHS) return false; const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT); unsigned ResultReg; if (Subtarget->hasAVX()) { // If we have AVX, create 1 blendv instead of 3 logic instructions. // Blendv was introduced with SSE 4.1, but the 2 register form implicitly // uses XMM0 as the selection register. That may need just as many // instructions as the AND/ANDN/OR sequence due to register moves, so // don't bother. unsigned CmpOpcode = (RetVT.SimpleTy == MVT::f32) ? X86::VCMPSSrr : X86::VCMPSDrr; unsigned BlendOpcode = (RetVT.SimpleTy == MVT::f32) ? X86::VBLENDVPSrr : X86::VBLENDVPDrr; unsigned CmpReg = fastEmitInst_rri(CmpOpcode, RC, CmpLHSReg, CmpLHSIsKill, CmpRHSReg, CmpRHSIsKill, CC); ResultReg = fastEmitInst_rrr(BlendOpcode, RC, RHSReg, RHSIsKill, LHSReg, LHSIsKill, CmpReg, true); } else { unsigned CmpReg = fastEmitInst_rri(Opc[0], RC, CmpLHSReg, CmpLHSIsKill, CmpRHSReg, CmpRHSIsKill, CC); unsigned AndReg = fastEmitInst_rr(Opc[1], RC, CmpReg, /*IsKill=*/false, LHSReg, LHSIsKill); unsigned AndNReg = fastEmitInst_rr(Opc[2], RC, CmpReg, /*IsKill=*/true, RHSReg, RHSIsKill); ResultReg = fastEmitInst_rr(Opc[3], RC, AndNReg, /*IsKill=*/true, AndReg, /*IsKill=*/true); } updateValueMap(I, ResultReg); return true; } bool X86FastISel::X86FastEmitPseudoSelect(MVT RetVT, const Instruction *I) { // These are pseudo CMOV instructions and will be later expanded into control- // flow. unsigned Opc; switch (RetVT.SimpleTy) { default: return false; case MVT::i8: Opc = X86::CMOV_GR8; break; case MVT::i16: Opc = X86::CMOV_GR16; break; case MVT::i32: Opc = X86::CMOV_GR32; break; case MVT::f32: Opc = X86::CMOV_FR32; break; case MVT::f64: Opc = X86::CMOV_FR64; break; } const Value *Cond = I->getOperand(0); X86::CondCode CC = X86::COND_NE; // Optimize conditions coming from a compare if both instructions are in the // same basic block (values defined in other basic blocks may not have // initialized registers). const auto *CI = dyn_cast(Cond); if (CI && (CI->getParent() == I->getParent())) { bool NeedSwap; std::tie(CC, NeedSwap) = getX86ConditionCode(CI->getPredicate()); if (CC > X86::LAST_VALID_COND) return false; const Value *CmpLHS = CI->getOperand(0); const Value *CmpRHS = CI->getOperand(1); if (NeedSwap) std::swap(CmpLHS, CmpRHS); EVT CmpVT = TLI.getValueType(CmpLHS->getType()); if (!X86FastEmitCompare(CmpLHS, CmpRHS, CmpVT, CI->getDebugLoc())) return false; } else { unsigned CondReg = getRegForValue(Cond); if (CondReg == 0) return false; bool CondIsKill = hasTrivialKill(Cond); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri)) .addReg(CondReg, getKillRegState(CondIsKill)).addImm(1); } const Value *LHS = I->getOperand(1); const Value *RHS = I->getOperand(2); unsigned LHSReg = getRegForValue(LHS); bool LHSIsKill = hasTrivialKill(LHS); unsigned RHSReg = getRegForValue(RHS); bool RHSIsKill = hasTrivialKill(RHS); if (!LHSReg || !RHSReg) return false; const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT); unsigned ResultReg = fastEmitInst_rri(Opc, RC, RHSReg, RHSIsKill, LHSReg, LHSIsKill, CC); updateValueMap(I, ResultReg); return true; } bool X86FastISel::X86SelectSelect(const Instruction *I) { MVT RetVT; if (!isTypeLegal(I->getType(), RetVT)) return false; // Check if we can fold the select. if (const auto *CI = dyn_cast(I->getOperand(0))) { CmpInst::Predicate Predicate = optimizeCmpPredicate(CI); const Value *Opnd = nullptr; switch (Predicate) { default: break; case CmpInst::FCMP_FALSE: Opnd = I->getOperand(2); break; case CmpInst::FCMP_TRUE: Opnd = I->getOperand(1); break; } // No need for a select anymore - this is an unconditional move. if (Opnd) { unsigned OpReg = getRegForValue(Opnd); if (OpReg == 0) return false; bool OpIsKill = hasTrivialKill(Opnd); const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT); unsigned ResultReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), ResultReg) .addReg(OpReg, getKillRegState(OpIsKill)); updateValueMap(I, ResultReg); return true; } } // First try to use real conditional move instructions. if (X86FastEmitCMoveSelect(RetVT, I)) return true; // Try to use a sequence of SSE instructions to simulate a conditional move. if (X86FastEmitSSESelect(RetVT, I)) return true; // Fall-back to pseudo conditional move instructions, which will be later // converted to control-flow. if (X86FastEmitPseudoSelect(RetVT, I)) return true; return false; } bool X86FastISel::X86SelectSIToFP(const Instruction *I) { if (!I->getOperand(0)->getType()->isIntegerTy(32)) return false; // Select integer to float/double conversion. unsigned OpReg = getRegForValue(I->getOperand(0)); if (OpReg == 0) return false; const TargetRegisterClass *RC = nullptr; unsigned Opcode; if (I->getType()->isDoubleTy()) { // sitofp int -> double Opcode = X86::VCVTSI2SDrr; RC = &X86::FR64RegClass; } else if (I->getType()->isFloatTy()) { // sitofp int -> float Opcode = X86::VCVTSI2SSrr; RC = &X86::FR32RegClass; } else return false; // The target-independent selection algorithm in FastISel already knows how // to select a SINT_TO_FP if the target is SSE but not AVX. This code is only // reachable if the subtarget has AVX. assert(Subtarget->hasAVX() && "Expected a subtarget with AVX!"); unsigned ImplicitDefReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg); unsigned ResultReg = fastEmitInst_rr(Opcode, RC, ImplicitDefReg, true, OpReg, false); updateValueMap(I, ResultReg); return true; } // Helper method used by X86SelectFPExt and X86SelectFPTrunc. bool X86FastISel::X86SelectFPExtOrFPTrunc(const Instruction *I, unsigned TargetOpc, const TargetRegisterClass *RC) { assert((I->getOpcode() == Instruction::FPExt || I->getOpcode() == Instruction::FPTrunc) && "Instruction must be an FPExt or FPTrunc!"); unsigned OpReg = getRegForValue(I->getOperand(0)); if (OpReg == 0) return false; unsigned ResultReg = createResultReg(RC); MachineInstrBuilder MIB; MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpc), ResultReg); if (Subtarget->hasAVX()) MIB.addReg(OpReg); MIB.addReg(OpReg); updateValueMap(I, ResultReg); return true; } bool X86FastISel::X86SelectFPExt(const Instruction *I) { if (X86ScalarSSEf64 && I->getType()->isDoubleTy() && I->getOperand(0)->getType()->isFloatTy()) { // fpext from float to double. unsigned Opc = Subtarget->hasAVX() ? X86::VCVTSS2SDrr : X86::CVTSS2SDrr; return X86SelectFPExtOrFPTrunc(I, Opc, &X86::FR64RegClass); } return false; } bool X86FastISel::X86SelectFPTrunc(const Instruction *I) { if (X86ScalarSSEf64 && I->getType()->isFloatTy() && I->getOperand(0)->getType()->isDoubleTy()) { // fptrunc from double to float. unsigned Opc = Subtarget->hasAVX() ? X86::VCVTSD2SSrr : X86::CVTSD2SSrr; return X86SelectFPExtOrFPTrunc(I, Opc, &X86::FR32RegClass); } return false; } bool X86FastISel::X86SelectTrunc(const Instruction *I) { EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType()); EVT DstVT = TLI.getValueType(I->getType()); // This code only handles truncation to byte. if (DstVT != MVT::i8 && DstVT != MVT::i1) return false; if (!TLI.isTypeLegal(SrcVT)) return false; unsigned InputReg = getRegForValue(I->getOperand(0)); if (!InputReg) // Unhandled operand. Halt "fast" selection and bail. return false; if (SrcVT == MVT::i8) { // Truncate from i8 to i1; no code needed. updateValueMap(I, InputReg); return true; } if (!Subtarget->is64Bit()) { // If we're on x86-32; we can't extract an i8 from a general register. // First issue a copy to GR16_ABCD or GR32_ABCD. const TargetRegisterClass *CopyRC = (SrcVT == MVT::i16) ? &X86::GR16_ABCDRegClass : &X86::GR32_ABCDRegClass; unsigned CopyReg = createResultReg(CopyRC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), CopyReg).addReg(InputReg); InputReg = CopyReg; } // Issue an extract_subreg. unsigned ResultReg = fastEmitInst_extractsubreg(MVT::i8, InputReg, /*Kill=*/true, X86::sub_8bit); if (!ResultReg) return false; updateValueMap(I, ResultReg); return true; } bool X86FastISel::IsMemcpySmall(uint64_t Len) { return Len <= (Subtarget->is64Bit() ? 32 : 16); } bool X86FastISel::TryEmitSmallMemcpy(X86AddressMode DestAM, X86AddressMode SrcAM, uint64_t Len) { // Make sure we don't bloat code by inlining very large memcpy's. if (!IsMemcpySmall(Len)) return false; bool i64Legal = Subtarget->is64Bit(); // We don't care about alignment here since we just emit integer accesses. while (Len) { MVT VT; if (Len >= 8 && i64Legal) VT = MVT::i64; else if (Len >= 4) VT = MVT::i32; else if (Len >= 2) VT = MVT::i16; else VT = MVT::i8; unsigned Reg; bool RV = X86FastEmitLoad(VT, SrcAM, nullptr, Reg); RV &= X86FastEmitStore(VT, Reg, /*Kill=*/true, DestAM); assert(RV && "Failed to emit load or store??"); unsigned Size = VT.getSizeInBits()/8; Len -= Size; DestAM.Disp += Size; SrcAM.Disp += Size; } return true; } bool X86FastISel::fastLowerIntrinsicCall(const IntrinsicInst *II) { // FIXME: Handle more intrinsics. switch (II->getIntrinsicID()) { default: return false; case Intrinsic::convert_from_fp16: case Intrinsic::convert_to_fp16: { if (TM.Options.UseSoftFloat || !Subtarget->hasF16C()) return false; const Value *Op = II->getArgOperand(0); unsigned InputReg = getRegForValue(Op); if (InputReg == 0) return false; // F16C only allows converting from float to half and from half to float. bool IsFloatToHalf = II->getIntrinsicID() == Intrinsic::convert_to_fp16; if (IsFloatToHalf) { if (!Op->getType()->isFloatTy()) return false; } else { if (!II->getType()->isFloatTy()) return false; } unsigned ResultReg = 0; const TargetRegisterClass *RC = TLI.getRegClassFor(MVT::v8i16); if (IsFloatToHalf) { // 'InputReg' is implicitly promoted from register class FR32 to // register class VR128 by method 'constrainOperandRegClass' which is // directly called by 'fastEmitInst_ri'. // Instruction VCVTPS2PHrr takes an extra immediate operand which is // used to provide rounding control. InputReg = fastEmitInst_ri(X86::VCVTPS2PHrr, RC, InputReg, false, 0); // Move the lower 32-bits of ResultReg to another register of class GR32. ResultReg = createResultReg(&X86::GR32RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::VMOVPDI2DIrr), ResultReg) .addReg(InputReg, RegState::Kill); // The result value is in the lower 16-bits of ResultReg. unsigned RegIdx = X86::sub_16bit; ResultReg = fastEmitInst_extractsubreg(MVT::i16, ResultReg, true, RegIdx); } else { assert(Op->getType()->isIntegerTy(16) && "Expected a 16-bit integer!"); // Explicitly sign-extend the input to 32-bit. InputReg = fastEmit_r(MVT::i16, MVT::i32, ISD::SIGN_EXTEND, InputReg, /*Kill=*/false); // The following SCALAR_TO_VECTOR will be expanded into a VMOVDI2PDIrr. InputReg = fastEmit_r(MVT::i32, MVT::v4i32, ISD::SCALAR_TO_VECTOR, InputReg, /*Kill=*/true); InputReg = fastEmitInst_r(X86::VCVTPH2PSrr, RC, InputReg, /*Kill=*/true); // The result value is in the lower 32-bits of ResultReg. // Emit an explicit copy from register class VR128 to register class FR32. ResultReg = createResultReg(&X86::FR32RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), ResultReg) .addReg(InputReg, RegState::Kill); } updateValueMap(II, ResultReg); return true; } case Intrinsic::frameaddress: { MachineFunction *MF = FuncInfo.MF; if (MF->getTarget().getMCAsmInfo()->usesWindowsCFI()) return false; Type *RetTy = II->getCalledFunction()->getReturnType(); MVT VT; if (!isTypeLegal(RetTy, VT)) return false; unsigned Opc; const TargetRegisterClass *RC = nullptr; switch (VT.SimpleTy) { default: llvm_unreachable("Invalid result type for frameaddress."); case MVT::i32: Opc = X86::MOV32rm; RC = &X86::GR32RegClass; break; case MVT::i64: Opc = X86::MOV64rm; RC = &X86::GR64RegClass; break; } // This needs to be set before we call getPtrSizedFrameRegister, otherwise // we get the wrong frame register. MachineFrameInfo *MFI = MF->getFrameInfo(); MFI->setFrameAddressIsTaken(true); const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo(); unsigned FrameReg = RegInfo->getPtrSizedFrameRegister(*MF); assert(((FrameReg == X86::RBP && VT == MVT::i64) || (FrameReg == X86::EBP && VT == MVT::i32)) && "Invalid Frame Register!"); // Always make a copy of the frame register to to a vreg first, so that we // never directly reference the frame register (the TwoAddressInstruction- // Pass doesn't like that). unsigned SrcReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), SrcReg).addReg(FrameReg); // Now recursively load from the frame address. // movq (%rbp), %rax // movq (%rax), %rax // movq (%rax), %rax // ... unsigned DestReg; unsigned Depth = cast(II->getOperand(0))->getZExtValue(); while (Depth--) { DestReg = createResultReg(RC); addDirectMem(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg), SrcReg); SrcReg = DestReg; } updateValueMap(II, SrcReg); return true; } case Intrinsic::memcpy: { const MemCpyInst *MCI = cast(II); // Don't handle volatile or variable length memcpys. if (MCI->isVolatile()) return false; if (isa(MCI->getLength())) { // Small memcpy's are common enough that we want to do them // without a call if possible. uint64_t Len = cast(MCI->getLength())->getZExtValue(); if (IsMemcpySmall(Len)) { X86AddressMode DestAM, SrcAM; if (!X86SelectAddress(MCI->getRawDest(), DestAM) || !X86SelectAddress(MCI->getRawSource(), SrcAM)) return false; TryEmitSmallMemcpy(DestAM, SrcAM, Len); return true; } } unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32; if (!MCI->getLength()->getType()->isIntegerTy(SizeWidth)) return false; if (MCI->getSourceAddressSpace() > 255 || MCI->getDestAddressSpace() > 255) return false; return lowerCallTo(II, "memcpy", II->getNumArgOperands() - 2); } case Intrinsic::memset: { const MemSetInst *MSI = cast(II); if (MSI->isVolatile()) return false; unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32; if (!MSI->getLength()->getType()->isIntegerTy(SizeWidth)) return false; if (MSI->getDestAddressSpace() > 255) return false; return lowerCallTo(II, "memset", II->getNumArgOperands() - 2); } case Intrinsic::stackprotector: { // Emit code to store the stack guard onto the stack. EVT PtrTy = TLI.getPointerTy(); const Value *Op1 = II->getArgOperand(0); // The guard's value. const AllocaInst *Slot = cast(II->getArgOperand(1)); MFI.setStackProtectorIndex(FuncInfo.StaticAllocaMap[Slot]); // Grab the frame index. X86AddressMode AM; if (!X86SelectAddress(Slot, AM)) return false; if (!X86FastEmitStore(PtrTy, Op1, AM)) return false; return true; } case Intrinsic::dbg_declare: { const DbgDeclareInst *DI = cast(II); X86AddressMode AM; assert(DI->getAddress() && "Null address should be checked earlier!"); if (!X86SelectAddress(DI->getAddress(), AM)) return false; const MCInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE); // FIXME may need to add RegState::Debug to any registers produced, // although ESP/EBP should be the only ones at the moment. assert(DI->getVariable()->isValidLocationForIntrinsic(DbgLoc) && "Expected inlined-at fields to agree"); addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II), AM) .addImm(0) .addMetadata(DI->getVariable()) .addMetadata(DI->getExpression()); return true; } case Intrinsic::trap: { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TRAP)); return true; } case Intrinsic::sqrt: { if (!Subtarget->hasSSE1()) return false; Type *RetTy = II->getCalledFunction()->getReturnType(); MVT VT; if (!isTypeLegal(RetTy, VT)) return false; // Unfortunately we can't use fastEmit_r, because the AVX version of FSQRT // is not generated by FastISel yet. // FIXME: Update this code once tablegen can handle it. static const unsigned SqrtOpc[2][2] = { {X86::SQRTSSr, X86::VSQRTSSr}, {X86::SQRTSDr, X86::VSQRTSDr} }; bool HasAVX = Subtarget->hasAVX(); unsigned Opc; const TargetRegisterClass *RC; switch (VT.SimpleTy) { default: return false; case MVT::f32: Opc = SqrtOpc[0][HasAVX]; RC = &X86::FR32RegClass; break; case MVT::f64: Opc = SqrtOpc[1][HasAVX]; RC = &X86::FR64RegClass; break; } const Value *SrcVal = II->getArgOperand(0); unsigned SrcReg = getRegForValue(SrcVal); if (SrcReg == 0) return false; unsigned ImplicitDefReg = 0; if (HasAVX) { ImplicitDefReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg); } unsigned ResultReg = createResultReg(RC); MachineInstrBuilder MIB; MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg); if (ImplicitDefReg) MIB.addReg(ImplicitDefReg); MIB.addReg(SrcReg); updateValueMap(II, ResultReg); return true; } case Intrinsic::sadd_with_overflow: case Intrinsic::uadd_with_overflow: case Intrinsic::ssub_with_overflow: case Intrinsic::usub_with_overflow: case Intrinsic::smul_with_overflow: case Intrinsic::umul_with_overflow: { // This implements the basic lowering of the xalu with overflow intrinsics // into add/sub/mul followed by either seto or setb. const Function *Callee = II->getCalledFunction(); auto *Ty = cast(Callee->getReturnType()); Type *RetTy = Ty->getTypeAtIndex(0U); Type *CondTy = Ty->getTypeAtIndex(1); MVT VT; if (!isTypeLegal(RetTy, VT)) return false; if (VT < MVT::i8 || VT > MVT::i64) return false; const Value *LHS = II->getArgOperand(0); const Value *RHS = II->getArgOperand(1); // Canonicalize immediate to the RHS. if (isa(LHS) && !isa(RHS) && isCommutativeIntrinsic(II)) std::swap(LHS, RHS); bool UseIncDec = false; if (isa(RHS) && cast(RHS)->isOne()) UseIncDec = true; unsigned BaseOpc, CondOpc; switch (II->getIntrinsicID()) { default: llvm_unreachable("Unexpected intrinsic!"); case Intrinsic::sadd_with_overflow: BaseOpc = UseIncDec ? unsigned(X86ISD::INC) : unsigned(ISD::ADD); CondOpc = X86::SETOr; break; case Intrinsic::uadd_with_overflow: BaseOpc = ISD::ADD; CondOpc = X86::SETBr; break; case Intrinsic::ssub_with_overflow: BaseOpc = UseIncDec ? unsigned(X86ISD::DEC) : unsigned(ISD::SUB); CondOpc = X86::SETOr; break; case Intrinsic::usub_with_overflow: BaseOpc = ISD::SUB; CondOpc = X86::SETBr; break; case Intrinsic::smul_with_overflow: BaseOpc = X86ISD::SMUL; CondOpc = X86::SETOr; break; case Intrinsic::umul_with_overflow: BaseOpc = X86ISD::UMUL; CondOpc = X86::SETOr; break; } unsigned LHSReg = getRegForValue(LHS); if (LHSReg == 0) return false; bool LHSIsKill = hasTrivialKill(LHS); unsigned ResultReg = 0; // Check if we have an immediate version. if (const auto *CI = dyn_cast(RHS)) { static const unsigned Opc[2][4] = { { X86::INC8r, X86::INC16r, X86::INC32r, X86::INC64r }, { X86::DEC8r, X86::DEC16r, X86::DEC32r, X86::DEC64r } }; if (BaseOpc == X86ISD::INC || BaseOpc == X86ISD::DEC) { ResultReg = createResultReg(TLI.getRegClassFor(VT)); bool IsDec = BaseOpc == X86ISD::DEC; BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc[IsDec][VT.SimpleTy-MVT::i8]), ResultReg) .addReg(LHSReg, getKillRegState(LHSIsKill)); } else ResultReg = fastEmit_ri(VT, VT, BaseOpc, LHSReg, LHSIsKill, CI->getZExtValue()); } unsigned RHSReg; bool RHSIsKill; if (!ResultReg) { RHSReg = getRegForValue(RHS); if (RHSReg == 0) return false; RHSIsKill = hasTrivialKill(RHS); ResultReg = fastEmit_rr(VT, VT, BaseOpc, LHSReg, LHSIsKill, RHSReg, RHSIsKill); } // FastISel doesn't have a pattern for all X86::MUL*r and X86::IMUL*r. Emit // it manually. if (BaseOpc == X86ISD::UMUL && !ResultReg) { static const unsigned MULOpc[] = { X86::MUL8r, X86::MUL16r, X86::MUL32r, X86::MUL64r }; static const unsigned Reg[] = { X86::AL, X86::AX, X86::EAX, X86::RAX }; // First copy the first operand into RAX, which is an implicit input to // the X86::MUL*r instruction. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), Reg[VT.SimpleTy-MVT::i8]) .addReg(LHSReg, getKillRegState(LHSIsKill)); ResultReg = fastEmitInst_r(MULOpc[VT.SimpleTy-MVT::i8], TLI.getRegClassFor(VT), RHSReg, RHSIsKill); } else if (BaseOpc == X86ISD::SMUL && !ResultReg) { static const unsigned MULOpc[] = { X86::IMUL8r, X86::IMUL16rr, X86::IMUL32rr, X86::IMUL64rr }; if (VT == MVT::i8) { // Copy the first operand into AL, which is an implicit input to the // X86::IMUL8r instruction. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), X86::AL) .addReg(LHSReg, getKillRegState(LHSIsKill)); ResultReg = fastEmitInst_r(MULOpc[0], TLI.getRegClassFor(VT), RHSReg, RHSIsKill); } else ResultReg = fastEmitInst_rr(MULOpc[VT.SimpleTy-MVT::i8], TLI.getRegClassFor(VT), LHSReg, LHSIsKill, RHSReg, RHSIsKill); } if (!ResultReg) return false; unsigned ResultReg2 = FuncInfo.CreateRegs(CondTy); assert((ResultReg+1) == ResultReg2 && "Nonconsecutive result registers."); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CondOpc), ResultReg2); updateValueMap(II, ResultReg, 2); return true; } case Intrinsic::x86_sse_cvttss2si: case Intrinsic::x86_sse_cvttss2si64: case Intrinsic::x86_sse2_cvttsd2si: case Intrinsic::x86_sse2_cvttsd2si64: { bool IsInputDouble; switch (II->getIntrinsicID()) { default: llvm_unreachable("Unexpected intrinsic."); case Intrinsic::x86_sse_cvttss2si: case Intrinsic::x86_sse_cvttss2si64: if (!Subtarget->hasSSE1()) return false; IsInputDouble = false; break; case Intrinsic::x86_sse2_cvttsd2si: case Intrinsic::x86_sse2_cvttsd2si64: if (!Subtarget->hasSSE2()) return false; IsInputDouble = true; break; } Type *RetTy = II->getCalledFunction()->getReturnType(); MVT VT; if (!isTypeLegal(RetTy, VT)) return false; static const unsigned CvtOpc[2][2][2] = { { { X86::CVTTSS2SIrr, X86::VCVTTSS2SIrr }, { X86::CVTTSS2SI64rr, X86::VCVTTSS2SI64rr } }, { { X86::CVTTSD2SIrr, X86::VCVTTSD2SIrr }, { X86::CVTTSD2SI64rr, X86::VCVTTSD2SI64rr } } }; bool HasAVX = Subtarget->hasAVX(); unsigned Opc; switch (VT.SimpleTy) { default: llvm_unreachable("Unexpected result type."); case MVT::i32: Opc = CvtOpc[IsInputDouble][0][HasAVX]; break; case MVT::i64: Opc = CvtOpc[IsInputDouble][1][HasAVX]; break; } // Check if we can fold insertelement instructions into the convert. const Value *Op = II->getArgOperand(0); while (auto *IE = dyn_cast(Op)) { const Value *Index = IE->getOperand(2); if (!isa(Index)) break; unsigned Idx = cast(Index)->getZExtValue(); if (Idx == 0) { Op = IE->getOperand(1); break; } Op = IE->getOperand(0); } unsigned Reg = getRegForValue(Op); if (Reg == 0) return false; unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT)); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg) .addReg(Reg); updateValueMap(II, ResultReg); return true; } } } bool X86FastISel::fastLowerArguments() { if (!FuncInfo.CanLowerReturn) return false; const Function *F = FuncInfo.Fn; if (F->isVarArg()) return false; CallingConv::ID CC = F->getCallingConv(); if (CC != CallingConv::C) return false; if (Subtarget->isCallingConvWin64(CC)) return false; if (!Subtarget->is64Bit()) return false; // Only handle simple cases. i.e. Up to 6 i32/i64 scalar arguments. unsigned GPRCnt = 0; unsigned FPRCnt = 0; unsigned Idx = 0; for (auto const &Arg : F->args()) { // The first argument is at index 1. ++Idx; if (F->getAttributes().hasAttribute(Idx, Attribute::ByVal) || F->getAttributes().hasAttribute(Idx, Attribute::InReg) || F->getAttributes().hasAttribute(Idx, Attribute::StructRet) || F->getAttributes().hasAttribute(Idx, Attribute::Nest)) return false; Type *ArgTy = Arg.getType(); if (ArgTy->isStructTy() || ArgTy->isArrayTy() || ArgTy->isVectorTy()) return false; EVT ArgVT = TLI.getValueType(ArgTy); if (!ArgVT.isSimple()) return false; switch (ArgVT.getSimpleVT().SimpleTy) { default: return false; case MVT::i32: case MVT::i64: ++GPRCnt; break; case MVT::f32: case MVT::f64: if (!Subtarget->hasSSE1()) return false; ++FPRCnt; break; } if (GPRCnt > 6) return false; if (FPRCnt > 8) return false; } static const MCPhysReg GPR32ArgRegs[] = { X86::EDI, X86::ESI, X86::EDX, X86::ECX, X86::R8D, X86::R9D }; static const MCPhysReg GPR64ArgRegs[] = { X86::RDI, X86::RSI, X86::RDX, X86::RCX, X86::R8 , X86::R9 }; static const MCPhysReg XMMArgRegs[] = { X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3, X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7 }; unsigned GPRIdx = 0; unsigned FPRIdx = 0; for (auto const &Arg : F->args()) { MVT VT = TLI.getSimpleValueType(Arg.getType()); const TargetRegisterClass *RC = TLI.getRegClassFor(VT); unsigned SrcReg; switch (VT.SimpleTy) { default: llvm_unreachable("Unexpected value type."); case MVT::i32: SrcReg = GPR32ArgRegs[GPRIdx++]; break; case MVT::i64: SrcReg = GPR64ArgRegs[GPRIdx++]; break; case MVT::f32: // fall-through case MVT::f64: SrcReg = XMMArgRegs[FPRIdx++]; break; } unsigned DstReg = FuncInfo.MF->addLiveIn(SrcReg, RC); // FIXME: Unfortunately it's necessary to emit a copy from the livein copy. // Without this, EmitLiveInCopies may eliminate the livein if its only // use is a bitcast (which isn't turned into an instruction). unsigned ResultReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), ResultReg) .addReg(DstReg, getKillRegState(true)); updateValueMap(&Arg, ResultReg); } return true; } static unsigned computeBytesPoppedByCallee(const X86Subtarget *Subtarget, CallingConv::ID CC, ImmutableCallSite *CS) { if (Subtarget->is64Bit()) return 0; if (Subtarget->getTargetTriple().isOSMSVCRT()) return 0; if (CC == CallingConv::Fast || CC == CallingConv::GHC || CC == CallingConv::HiPE) return 0; if (CS && !CS->paramHasAttr(1, Attribute::StructRet)) return 0; if (CS && CS->paramHasAttr(1, Attribute::InReg)) return 0; return 4; } bool X86FastISel::fastLowerCall(CallLoweringInfo &CLI) { auto &OutVals = CLI.OutVals; auto &OutFlags = CLI.OutFlags; auto &OutRegs = CLI.OutRegs; auto &Ins = CLI.Ins; auto &InRegs = CLI.InRegs; CallingConv::ID CC = CLI.CallConv; bool &IsTailCall = CLI.IsTailCall; bool IsVarArg = CLI.IsVarArg; const Value *Callee = CLI.Callee; const char *SymName = CLI.SymName; bool Is64Bit = Subtarget->is64Bit(); bool IsWin64 = Subtarget->isCallingConvWin64(CC); // Handle only C, fastcc, and webkit_js calling conventions for now. switch (CC) { default: return false; case CallingConv::C: case CallingConv::Fast: case CallingConv::WebKit_JS: case CallingConv::X86_FastCall: case CallingConv::X86_64_Win64: case CallingConv::X86_64_SysV: break; } // Allow SelectionDAG isel to handle tail calls. if (IsTailCall) return false; // fastcc with -tailcallopt is intended to provide a guaranteed // tail call optimization. Fastisel doesn't know how to do that. if (CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt) return false; // Don't know how to handle Win64 varargs yet. Nothing special needed for // x86-32. Special handling for x86-64 is implemented. if (IsVarArg && IsWin64) return false; // Don't know about inalloca yet. if (CLI.CS && CLI.CS->hasInAllocaArgument()) return false; // Fast-isel doesn't know about callee-pop yet. if (X86::isCalleePop(CC, Subtarget->is64Bit(), IsVarArg, TM.Options.GuaranteedTailCallOpt)) return false; SmallVector OutVTs; SmallVector ArgRegs; // If this is a constant i1/i8/i16 argument, promote to i32 to avoid an extra // instruction. This is safe because it is common to all FastISel supported // calling conventions on x86. for (int i = 0, e = OutVals.size(); i != e; ++i) { Value *&Val = OutVals[i]; ISD::ArgFlagsTy Flags = OutFlags[i]; if (auto *CI = dyn_cast(Val)) { if (CI->getBitWidth() < 32) { if (Flags.isSExt()) Val = ConstantExpr::getSExt(CI, Type::getInt32Ty(CI->getContext())); else Val = ConstantExpr::getZExt(CI, Type::getInt32Ty(CI->getContext())); } } // Passing bools around ends up doing a trunc to i1 and passing it. // Codegen this as an argument + "and 1". MVT VT; auto *TI = dyn_cast(Val); unsigned ResultReg; if (TI && TI->getType()->isIntegerTy(1) && CLI.CS && (TI->getParent() == CLI.CS->getInstruction()->getParent()) && TI->hasOneUse()) { Value *PrevVal = TI->getOperand(0); ResultReg = getRegForValue(PrevVal); if (!ResultReg) return false; if (!isTypeLegal(PrevVal->getType(), VT)) return false; ResultReg = fastEmit_ri(VT, VT, ISD::AND, ResultReg, hasTrivialKill(PrevVal), 1); } else { if (!isTypeLegal(Val->getType(), VT)) return false; ResultReg = getRegForValue(Val); } if (!ResultReg) return false; ArgRegs.push_back(ResultReg); OutVTs.push_back(VT); } // Analyze operands of the call, assigning locations to each operand. SmallVector ArgLocs; CCState CCInfo(CC, IsVarArg, *FuncInfo.MF, ArgLocs, CLI.RetTy->getContext()); // Allocate shadow area for Win64 if (IsWin64) CCInfo.AllocateStack(32, 8); CCInfo.AnalyzeCallOperands(OutVTs, OutFlags, CC_X86); // Get a count of how many bytes are to be pushed on the stack. unsigned NumBytes = CCInfo.getNextStackOffset(); // Issue CALLSEQ_START unsigned AdjStackDown = TII.getCallFrameSetupOpcode(); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackDown)) .addImm(NumBytes).addImm(0); // Walk the register/memloc assignments, inserting copies/loads. const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo(); for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign const &VA = ArgLocs[i]; const Value *ArgVal = OutVals[VA.getValNo()]; MVT ArgVT = OutVTs[VA.getValNo()]; if (ArgVT == MVT::x86mmx) return false; unsigned ArgReg = ArgRegs[VA.getValNo()]; // Promote the value if needed. switch (VA.getLocInfo()) { case CCValAssign::Full: break; case CCValAssign::SExt: { assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() && "Unexpected extend"); bool Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(), ArgReg, ArgVT, ArgReg); assert(Emitted && "Failed to emit a sext!"); (void)Emitted; ArgVT = VA.getLocVT(); break; } case CCValAssign::ZExt: { assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() && "Unexpected extend"); bool Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(), ArgReg, ArgVT, ArgReg); assert(Emitted && "Failed to emit a zext!"); (void)Emitted; ArgVT = VA.getLocVT(); break; } case CCValAssign::AExt: { assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() && "Unexpected extend"); bool Emitted = X86FastEmitExtend(ISD::ANY_EXTEND, VA.getLocVT(), ArgReg, ArgVT, ArgReg); if (!Emitted) Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(), ArgReg, ArgVT, ArgReg); if (!Emitted) Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(), ArgReg, ArgVT, ArgReg); assert(Emitted && "Failed to emit a aext!"); (void)Emitted; ArgVT = VA.getLocVT(); break; } case CCValAssign::BCvt: { ArgReg = fastEmit_r(ArgVT, VA.getLocVT(), ISD::BITCAST, ArgReg, /*TODO: Kill=*/false); assert(ArgReg && "Failed to emit a bitcast!"); ArgVT = VA.getLocVT(); break; } case CCValAssign::VExt: // VExt has not been implemented, so this should be impossible to reach // for now. However, fallback to Selection DAG isel once implemented. return false; case CCValAssign::AExtUpper: case CCValAssign::SExtUpper: case CCValAssign::ZExtUpper: case CCValAssign::FPExt: llvm_unreachable("Unexpected loc info!"); case CCValAssign::Indirect: // FIXME: Indirect doesn't need extending, but fast-isel doesn't fully // support this. return false; } if (VA.isRegLoc()) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), VA.getLocReg()).addReg(ArgReg); OutRegs.push_back(VA.getLocReg()); } else { assert(VA.isMemLoc()); // Don't emit stores for undef values. if (isa(ArgVal)) continue; unsigned LocMemOffset = VA.getLocMemOffset(); X86AddressMode AM; AM.Base.Reg = RegInfo->getStackRegister(); AM.Disp = LocMemOffset; ISD::ArgFlagsTy Flags = OutFlags[VA.getValNo()]; unsigned Alignment = DL.getABITypeAlignment(ArgVal->getType()); MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand( MachinePointerInfo::getStack(LocMemOffset), MachineMemOperand::MOStore, ArgVT.getStoreSize(), Alignment); if (Flags.isByVal()) { X86AddressMode SrcAM; SrcAM.Base.Reg = ArgReg; if (!TryEmitSmallMemcpy(AM, SrcAM, Flags.getByValSize())) return false; } else if (isa(ArgVal) || isa(ArgVal)) { // If this is a really simple value, emit this with the Value* version // of X86FastEmitStore. If it isn't simple, we don't want to do this, // as it can cause us to reevaluate the argument. if (!X86FastEmitStore(ArgVT, ArgVal, AM, MMO)) return false; } else { bool ValIsKill = hasTrivialKill(ArgVal); if (!X86FastEmitStore(ArgVT, ArgReg, ValIsKill, AM, MMO)) return false; } } } // ELF / PIC requires GOT in the EBX register before function calls via PLT // GOT pointer. if (Subtarget->isPICStyleGOT()) { unsigned Base = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), X86::EBX).addReg(Base); } if (Is64Bit && IsVarArg && !IsWin64) { // From AMD64 ABI document: // For calls that may call functions that use varargs or stdargs // (prototype-less calls or calls to functions containing ellipsis (...) in // the declaration) %al is used as hidden argument to specify the number // of SSE registers used. The contents of %al do not need to match exactly // the number of registers, but must be an ubound on the number of SSE // registers used and is in the range 0 - 8 inclusive. // Count the number of XMM registers allocated. static const MCPhysReg XMMArgRegs[] = { X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3, X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7 }; unsigned NumXMMRegs = CCInfo.getFirstUnallocated(XMMArgRegs); assert((Subtarget->hasSSE1() || !NumXMMRegs) && "SSE registers cannot be used when SSE is disabled"); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV8ri), X86::AL).addImm(NumXMMRegs); } // Materialize callee address in a register. FIXME: GV address can be // handled with a CALLpcrel32 instead. X86AddressMode CalleeAM; if (!X86SelectCallAddress(Callee, CalleeAM)) return false; unsigned CalleeOp = 0; const GlobalValue *GV = nullptr; if (CalleeAM.GV != nullptr) { GV = CalleeAM.GV; } else if (CalleeAM.Base.Reg != 0) { CalleeOp = CalleeAM.Base.Reg; } else return false; // Issue the call. MachineInstrBuilder MIB; if (CalleeOp) { // Register-indirect call. unsigned CallOpc = Is64Bit ? X86::CALL64r : X86::CALL32r; MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CallOpc)) .addReg(CalleeOp); } else { // Direct call. assert(GV && "Not a direct call"); unsigned CallOpc = Is64Bit ? X86::CALL64pcrel32 : X86::CALLpcrel32; // See if we need any target-specific flags on the GV operand. unsigned char OpFlags = 0; // On ELF targets, in both X86-64 and X86-32 mode, direct calls to // external symbols most go through the PLT in PIC mode. If the symbol // has hidden or protected visibility, or if it is static or local, then // we don't need to use the PLT - we can directly call it. if (Subtarget->isTargetELF() && TM.getRelocationModel() == Reloc::PIC_ && GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) { OpFlags = X86II::MO_PLT; } else if (Subtarget->isPICStyleStubAny() && (GV->isDeclaration() || GV->isWeakForLinker()) && (!Subtarget->getTargetTriple().isMacOSX() || Subtarget->getTargetTriple().isMacOSXVersionLT(10, 5))) { // PC-relative references to external symbols should go through $stub, // unless we're building with the leopard linker or later, which // automatically synthesizes these stubs. OpFlags = X86II::MO_DARWIN_STUB; } MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CallOpc)); if (SymName) MIB.addExternalSymbol(SymName, OpFlags); else MIB.addGlobalAddress(GV, 0, OpFlags); } // Add a register mask operand representing the call-preserved registers. // Proper defs for return values will be added by setPhysRegsDeadExcept(). MIB.addRegMask(TRI.getCallPreservedMask(*FuncInfo.MF, CC)); // Add an implicit use GOT pointer in EBX. if (Subtarget->isPICStyleGOT()) MIB.addReg(X86::EBX, RegState::Implicit); if (Is64Bit && IsVarArg && !IsWin64) MIB.addReg(X86::AL, RegState::Implicit); // Add implicit physical register uses to the call. for (auto Reg : OutRegs) MIB.addReg(Reg, RegState::Implicit); // Issue CALLSEQ_END unsigned NumBytesForCalleeToPop = computeBytesPoppedByCallee(Subtarget, CC, CLI.CS); unsigned AdjStackUp = TII.getCallFrameDestroyOpcode(); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackUp)) .addImm(NumBytes).addImm(NumBytesForCalleeToPop); // Now handle call return values. SmallVector RVLocs; CCState CCRetInfo(CC, IsVarArg, *FuncInfo.MF, RVLocs, CLI.RetTy->getContext()); CCRetInfo.AnalyzeCallResult(Ins, RetCC_X86); // Copy all of the result registers out of their specified physreg. unsigned ResultReg = FuncInfo.CreateRegs(CLI.RetTy); for (unsigned i = 0; i != RVLocs.size(); ++i) { CCValAssign &VA = RVLocs[i]; EVT CopyVT = VA.getValVT(); unsigned CopyReg = ResultReg + i; // If this is x86-64, and we disabled SSE, we can't return FP values if ((CopyVT == MVT::f32 || CopyVT == MVT::f64) && ((Is64Bit || Ins[i].Flags.isInReg()) && !Subtarget->hasSSE1())) { report_fatal_error("SSE register return with SSE disabled"); } // If we prefer to use the value in xmm registers, copy it out as f80 and // use a truncate to move it from fp stack reg to xmm reg. if ((VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1) && isScalarFPTypeInSSEReg(VA.getValVT())) { CopyVT = MVT::f80; CopyReg = createResultReg(&X86::RFP80RegClass); } // Copy out the result. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY), CopyReg).addReg(VA.getLocReg()); InRegs.push_back(VA.getLocReg()); // Round the f80 to the right size, which also moves it to the appropriate // xmm register. This is accomplished by storing the f80 value in memory // and then loading it back. if (CopyVT != VA.getValVT()) { EVT ResVT = VA.getValVT(); unsigned Opc = ResVT == MVT::f32 ? X86::ST_Fp80m32 : X86::ST_Fp80m64; unsigned MemSize = ResVT.getSizeInBits()/8; int FI = MFI.CreateStackObject(MemSize, MemSize, false); addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc)), FI) .addReg(CopyReg); Opc = ResVT == MVT::f32 ? X86::MOVSSrm : X86::MOVSDrm; addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg + i), FI); } } CLI.ResultReg = ResultReg; CLI.NumResultRegs = RVLocs.size(); CLI.Call = MIB; return true; } bool X86FastISel::fastSelectInstruction(const Instruction *I) { switch (I->getOpcode()) { default: break; case Instruction::Load: return X86SelectLoad(I); case Instruction::Store: return X86SelectStore(I); case Instruction::Ret: return X86SelectRet(I); case Instruction::ICmp: case Instruction::FCmp: return X86SelectCmp(I); case Instruction::ZExt: return X86SelectZExt(I); case Instruction::Br: return X86SelectBranch(I); case Instruction::LShr: case Instruction::AShr: case Instruction::Shl: return X86SelectShift(I); case Instruction::SDiv: case Instruction::UDiv: case Instruction::SRem: case Instruction::URem: return X86SelectDivRem(I); case Instruction::Select: return X86SelectSelect(I); case Instruction::Trunc: return X86SelectTrunc(I); case Instruction::FPExt: return X86SelectFPExt(I); case Instruction::FPTrunc: return X86SelectFPTrunc(I); case Instruction::SIToFP: return X86SelectSIToFP(I); case Instruction::IntToPtr: // Deliberate fall-through. case Instruction::PtrToInt: { EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType()); EVT DstVT = TLI.getValueType(I->getType()); if (DstVT.bitsGT(SrcVT)) return X86SelectZExt(I); if (DstVT.bitsLT(SrcVT)) return X86SelectTrunc(I); unsigned Reg = getRegForValue(I->getOperand(0)); if (Reg == 0) return false; updateValueMap(I, Reg); return true; } } return false; } unsigned X86FastISel::X86MaterializeInt(const ConstantInt *CI, MVT VT) { if (VT > MVT::i64) return 0; uint64_t Imm = CI->getZExtValue(); if (Imm == 0) { unsigned SrcReg = fastEmitInst_(X86::MOV32r0, &X86::GR32RegClass); switch (VT.SimpleTy) { default: llvm_unreachable("Unexpected value type"); case MVT::i1: case MVT::i8: return fastEmitInst_extractsubreg(MVT::i8, SrcReg, /*Kill=*/true, X86::sub_8bit); case MVT::i16: return fastEmitInst_extractsubreg(MVT::i16, SrcReg, /*Kill=*/true, X86::sub_16bit); case MVT::i32: return SrcReg; case MVT::i64: { unsigned ResultReg = createResultReg(&X86::GR64RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::SUBREG_TO_REG), ResultReg) .addImm(0).addReg(SrcReg).addImm(X86::sub_32bit); return ResultReg; } } } unsigned Opc = 0; switch (VT.SimpleTy) { default: llvm_unreachable("Unexpected value type"); case MVT::i1: VT = MVT::i8; // fall-through case MVT::i8: Opc = X86::MOV8ri; break; case MVT::i16: Opc = X86::MOV16ri; break; case MVT::i32: Opc = X86::MOV32ri; break; case MVT::i64: { if (isUInt<32>(Imm)) Opc = X86::MOV32ri; else if (isInt<32>(Imm)) Opc = X86::MOV64ri32; else Opc = X86::MOV64ri; break; } } if (VT == MVT::i64 && Opc == X86::MOV32ri) { unsigned SrcReg = fastEmitInst_i(Opc, &X86::GR32RegClass, Imm); unsigned ResultReg = createResultReg(&X86::GR64RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::SUBREG_TO_REG), ResultReg) .addImm(0).addReg(SrcReg).addImm(X86::sub_32bit); return ResultReg; } return fastEmitInst_i(Opc, TLI.getRegClassFor(VT), Imm); } unsigned X86FastISel::X86MaterializeFP(const ConstantFP *CFP, MVT VT) { if (CFP->isNullValue()) return fastMaterializeFloatZero(CFP); // Can't handle alternate code models yet. CodeModel::Model CM = TM.getCodeModel(); if (CM != CodeModel::Small && CM != CodeModel::Large) return 0; // Get opcode and regclass of the output for the given load instruction. unsigned Opc = 0; const TargetRegisterClass *RC = nullptr; switch (VT.SimpleTy) { default: return 0; case MVT::f32: if (X86ScalarSSEf32) { Opc = Subtarget->hasAVX() ? X86::VMOVSSrm : X86::MOVSSrm; RC = &X86::FR32RegClass; } else { Opc = X86::LD_Fp32m; RC = &X86::RFP32RegClass; } break; case MVT::f64: if (X86ScalarSSEf64) { Opc = Subtarget->hasAVX() ? X86::VMOVSDrm : X86::MOVSDrm; RC = &X86::FR64RegClass; } else { Opc = X86::LD_Fp64m; RC = &X86::RFP64RegClass; } break; case MVT::f80: // No f80 support yet. return 0; } // MachineConstantPool wants an explicit alignment. unsigned Align = DL.getPrefTypeAlignment(CFP->getType()); if (Align == 0) { // Alignment of vector types. FIXME! Align = DL.getTypeAllocSize(CFP->getType()); } // x86-32 PIC requires a PIC base register for constant pools. unsigned PICBase = 0; unsigned char OpFlag = 0; if (Subtarget->isPICStyleStubPIC()) { // Not dynamic-no-pic OpFlag = X86II::MO_PIC_BASE_OFFSET; PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF); } else if (Subtarget->isPICStyleGOT()) { OpFlag = X86II::MO_GOTOFF; PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF); } else if (Subtarget->isPICStyleRIPRel() && TM.getCodeModel() == CodeModel::Small) { PICBase = X86::RIP; } // Create the load from the constant pool. unsigned CPI = MCP.getConstantPoolIndex(CFP, Align); unsigned ResultReg = createResultReg(RC); if (CM == CodeModel::Large) { unsigned AddrReg = createResultReg(&X86::GR64RegClass); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV64ri), AddrReg) .addConstantPoolIndex(CPI, 0, OpFlag); MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg); addDirectMem(MIB, AddrReg); MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand( MachinePointerInfo::getConstantPool(), MachineMemOperand::MOLoad, TM.getDataLayout()->getPointerSize(), Align); MIB->addMemOperand(*FuncInfo.MF, MMO); return ResultReg; } addConstantPoolReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg), CPI, PICBase, OpFlag); return ResultReg; } unsigned X86FastISel::X86MaterializeGV(const GlobalValue *GV, MVT VT) { // Can't handle alternate code models yet. if (TM.getCodeModel() != CodeModel::Small) return 0; // Materialize addresses with LEA/MOV instructions. X86AddressMode AM; if (X86SelectAddress(GV, AM)) { // If the expression is just a basereg, then we're done, otherwise we need // to emit an LEA. if (AM.BaseType == X86AddressMode::RegBase && AM.IndexReg == 0 && AM.Disp == 0 && AM.GV == nullptr) return AM.Base.Reg; unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT)); if (TM.getRelocationModel() == Reloc::Static && TLI.getPointerTy() == MVT::i64) { // The displacement code could be more than 32 bits away so we need to use // an instruction with a 64 bit immediate BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV64ri), ResultReg) .addGlobalAddress(GV); } else { unsigned Opc = TLI.getPointerTy() == MVT::i32 ? (Subtarget->isTarget64BitILP32() ? X86::LEA64_32r : X86::LEA32r) : X86::LEA64r; addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg), AM); } return ResultReg; } return 0; } unsigned X86FastISel::fastMaterializeConstant(const Constant *C) { EVT CEVT = TLI.getValueType(C->getType(), true); // Only handle simple types. if (!CEVT.isSimple()) return 0; MVT VT = CEVT.getSimpleVT(); if (const auto *CI = dyn_cast(C)) return X86MaterializeInt(CI, VT); else if (const ConstantFP *CFP = dyn_cast(C)) return X86MaterializeFP(CFP, VT); else if (const GlobalValue *GV = dyn_cast(C)) return X86MaterializeGV(GV, VT); return 0; } unsigned X86FastISel::fastMaterializeAlloca(const AllocaInst *C) { // Fail on dynamic allocas. At this point, getRegForValue has already // checked its CSE maps, so if we're here trying to handle a dynamic // alloca, we're not going to succeed. X86SelectAddress has a // check for dynamic allocas, because it's called directly from // various places, but targetMaterializeAlloca also needs a check // in order to avoid recursion between getRegForValue, // X86SelectAddrss, and targetMaterializeAlloca. if (!FuncInfo.StaticAllocaMap.count(C)) return 0; assert(C->isStaticAlloca() && "dynamic alloca in the static alloca map?"); X86AddressMode AM; if (!X86SelectAddress(C, AM)) return 0; unsigned Opc = TLI.getPointerTy() == MVT::i32 ? (Subtarget->isTarget64BitILP32() ? X86::LEA64_32r : X86::LEA32r) : X86::LEA64r; const TargetRegisterClass* RC = TLI.getRegClassFor(TLI.getPointerTy()); unsigned ResultReg = createResultReg(RC); addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg), AM); return ResultReg; } unsigned X86FastISel::fastMaterializeFloatZero(const ConstantFP *CF) { MVT VT; if (!isTypeLegal(CF->getType(), VT)) return 0; // Get opcode and regclass for the given zero. unsigned Opc = 0; const TargetRegisterClass *RC = nullptr; switch (VT.SimpleTy) { default: return 0; case MVT::f32: if (X86ScalarSSEf32) { Opc = X86::FsFLD0SS; RC = &X86::FR32RegClass; } else { Opc = X86::LD_Fp032; RC = &X86::RFP32RegClass; } break; case MVT::f64: if (X86ScalarSSEf64) { Opc = X86::FsFLD0SD; RC = &X86::FR64RegClass; } else { Opc = X86::LD_Fp064; RC = &X86::RFP64RegClass; } break; case MVT::f80: // No f80 support yet. return 0; } unsigned ResultReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg); return ResultReg; } bool X86FastISel::tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo, const LoadInst *LI) { const Value *Ptr = LI->getPointerOperand(); X86AddressMode AM; if (!X86SelectAddress(Ptr, AM)) return false; const X86InstrInfo &XII = (const X86InstrInfo &)TII; unsigned Size = DL.getTypeAllocSize(LI->getType()); unsigned Alignment = LI->getAlignment(); if (Alignment == 0) // Ensure that codegen never sees alignment 0 Alignment = DL.getABITypeAlignment(LI->getType()); SmallVector AddrOps; AM.getFullAddress(AddrOps); MachineInstr *Result = XII.foldMemoryOperandImpl(*FuncInfo.MF, MI, OpNo, AddrOps, Size, Alignment, /*AllowCommute=*/true); if (!Result) return false; Result->addMemOperand(*FuncInfo.MF, createMachineMemOperandFor(LI)); FuncInfo.MBB->insert(FuncInfo.InsertPt, Result); MI->eraseFromParent(); return true; } namespace llvm { FastISel *X86::createFastISel(FunctionLoweringInfo &funcInfo, const TargetLibraryInfo *libInfo) { return new X86FastISel(funcInfo, libInfo); } }