//===-- MipsISelLowering.cpp - Mips DAG Lowering 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 interfaces that Mips uses to lower LLVM code into a // selection DAG. // //===----------------------------------------------------------------------===// #define DEBUG_TYPE "mips-lower" #include "MipsISelLowering.h" #include "MipsMachineFunction.h" #include "MipsTargetMachine.h" #include "MipsTargetObjectFile.h" #include "MipsSubtarget.h" #include "llvm/DerivedTypes.h" #include "llvm/Function.h" #include "llvm/GlobalVariable.h" #include "llvm/Intrinsics.h" #include "llvm/CallingConv.h" #include "InstPrinter/MipsInstPrinter.h" #include "MCTargetDesc/MipsBaseInfo.h" #include "llvm/CodeGen/CallingConvLower.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/SelectionDAGISel.h" #include "llvm/CodeGen/ValueTypes.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" using namespace llvm; // If I is a shifted mask, set the size (Size) and the first bit of the // mask (Pos), and return true. // For example, if I is 0x003ff800, (Pos, Size) = (11, 11). static bool IsShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) { if (!isUInt<32>(I) || !isShiftedMask_32(I)) return false; Size = CountPopulation_32(I); Pos = CountTrailingZeros_32(I); return true; } const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const { switch (Opcode) { case MipsISD::JmpLink: return "MipsISD::JmpLink"; case MipsISD::Hi: return "MipsISD::Hi"; case MipsISD::Lo: return "MipsISD::Lo"; case MipsISD::GPRel: return "MipsISD::GPRel"; case MipsISD::TlsGd: return "MipsISD::TlsGd"; case MipsISD::TprelHi: return "MipsISD::TprelHi"; case MipsISD::TprelLo: return "MipsISD::TprelLo"; case MipsISD::ThreadPointer: return "MipsISD::ThreadPointer"; case MipsISD::Ret: return "MipsISD::Ret"; case MipsISD::FPBrcond: return "MipsISD::FPBrcond"; case MipsISD::FPCmp: return "MipsISD::FPCmp"; case MipsISD::CMovFP_T: return "MipsISD::CMovFP_T"; case MipsISD::CMovFP_F: return "MipsISD::CMovFP_F"; case MipsISD::FPRound: return "MipsISD::FPRound"; case MipsISD::MAdd: return "MipsISD::MAdd"; case MipsISD::MAddu: return "MipsISD::MAddu"; case MipsISD::MSub: return "MipsISD::MSub"; case MipsISD::MSubu: return "MipsISD::MSubu"; case MipsISD::DivRem: return "MipsISD::DivRem"; case MipsISD::DivRemU: return "MipsISD::DivRemU"; case MipsISD::BuildPairF64: return "MipsISD::BuildPairF64"; case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64"; case MipsISD::WrapperPIC: return "MipsISD::WrapperPIC"; case MipsISD::DynAlloc: return "MipsISD::DynAlloc"; case MipsISD::Sync: return "MipsISD::Sync"; case MipsISD::Ext: return "MipsISD::Ext"; case MipsISD::Ins: return "MipsISD::Ins"; default: return NULL; } } MipsTargetLowering:: MipsTargetLowering(MipsTargetMachine &TM) : TargetLowering(TM, new MipsTargetObjectFile()), Subtarget(&TM.getSubtarget()), HasMips64(Subtarget->hasMips64()), IsN64(Subtarget->isABI_N64()), IsO32(Subtarget->isABI_O32()) { // Mips does not have i1 type, so use i32 for // setcc operations results (slt, sgt, ...). setBooleanContents(ZeroOrOneBooleanContent); setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct? // Set up the register classes addRegisterClass(MVT::i32, Mips::CPURegsRegisterClass); addRegisterClass(MVT::f32, Mips::FGR32RegisterClass); if (HasMips64) addRegisterClass(MVT::i64, Mips::CPU64RegsRegisterClass); // When dealing with single precision only, use libcalls if (!Subtarget->isSingleFloat()) { if (HasMips64) addRegisterClass(MVT::f64, Mips::FGR64RegisterClass); else addRegisterClass(MVT::f64, Mips::AFGR64RegisterClass); } // Load extented operations for i1 types must be promoted setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote); // MIPS doesn't have extending float->double load/store setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand); setTruncStoreAction(MVT::f64, MVT::f32, Expand); // Used by legalize types to correctly generate the setcc result. // Without this, every float setcc comes with a AND/OR with the result, // we don't want this, since the fpcmp result goes to a flag register, // which is used implicitly by brcond and select operations. AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32); // Mips Custom Operations setOperationAction(ISD::GlobalAddress, MVT::i32, Custom); setOperationAction(ISD::GlobalAddress, MVT::i64, Custom); setOperationAction(ISD::BlockAddress, MVT::i32, Custom); setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom); setOperationAction(ISD::JumpTable, MVT::i32, Custom); setOperationAction(ISD::ConstantPool, MVT::i32, Custom); setOperationAction(ISD::SELECT, MVT::f32, Custom); setOperationAction(ISD::SELECT, MVT::f64, Custom); setOperationAction(ISD::SELECT, MVT::i32, Custom); setOperationAction(ISD::BRCOND, MVT::Other, Custom); setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom); setOperationAction(ISD::VASTART, MVT::Other, Custom); setOperationAction(ISD::SDIV, MVT::i32, Expand); setOperationAction(ISD::SREM, MVT::i32, Expand); setOperationAction(ISD::UDIV, MVT::i32, Expand); setOperationAction(ISD::UREM, MVT::i32, Expand); setOperationAction(ISD::SDIV, MVT::i64, Expand); setOperationAction(ISD::SREM, MVT::i64, Expand); setOperationAction(ISD::UDIV, MVT::i64, Expand); setOperationAction(ISD::UREM, MVT::i64, Expand); // Operations not directly supported by Mips. setOperationAction(ISD::BR_JT, MVT::Other, Expand); setOperationAction(ISD::BR_CC, MVT::Other, Expand); setOperationAction(ISD::SELECT_CC, MVT::Other, Expand); setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand); setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand); setOperationAction(ISD::CTPOP, MVT::i32, Expand); setOperationAction(ISD::CTTZ, MVT::i32, Expand); setOperationAction(ISD::ROTL, MVT::i32, Expand); setOperationAction(ISD::ROTL, MVT::i64, Expand); if (!Subtarget->hasMips32r2()) setOperationAction(ISD::ROTR, MVT::i32, Expand); if (!Subtarget->hasMips64r2()) setOperationAction(ISD::ROTR, MVT::i64, Expand); setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand); setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand); setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand); setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom); setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom); setOperationAction(ISD::FSIN, MVT::f32, Expand); setOperationAction(ISD::FSIN, MVT::f64, Expand); setOperationAction(ISD::FCOS, MVT::f32, Expand); setOperationAction(ISD::FCOS, MVT::f64, Expand); setOperationAction(ISD::FPOWI, MVT::f32, Expand); setOperationAction(ISD::FPOW, MVT::f32, Expand); setOperationAction(ISD::FPOW, MVT::f64, Expand); setOperationAction(ISD::FLOG, MVT::f32, Expand); setOperationAction(ISD::FLOG2, MVT::f32, Expand); setOperationAction(ISD::FLOG10, MVT::f32, Expand); setOperationAction(ISD::FEXP, MVT::f32, Expand); setOperationAction(ISD::FMA, MVT::f32, Expand); setOperationAction(ISD::FMA, MVT::f64, Expand); setOperationAction(ISD::EXCEPTIONADDR, MVT::i32, Expand); setOperationAction(ISD::EHSELECTION, MVT::i32, Expand); setOperationAction(ISD::VAARG, MVT::Other, Expand); setOperationAction(ISD::VACOPY, MVT::Other, Expand); setOperationAction(ISD::VAEND, MVT::Other, Expand); // Use the default for now setOperationAction(ISD::STACKSAVE, MVT::Other, Expand); setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand); setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom); setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Custom); setOperationAction(ISD::ATOMIC_LOAD, MVT::i32, Expand); setOperationAction(ISD::ATOMIC_STORE, MVT::i32, Expand); setInsertFencesForAtomic(true); if (Subtarget->isSingleFloat()) setOperationAction(ISD::SELECT_CC, MVT::f64, Expand); if (!Subtarget->hasSEInReg()) { setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand); } if (!Subtarget->hasBitCount()) setOperationAction(ISD::CTLZ, MVT::i32, Expand); if (!Subtarget->hasSwap()) setOperationAction(ISD::BSWAP, MVT::i32, Expand); setTargetDAGCombine(ISD::ADDE); setTargetDAGCombine(ISD::SUBE); setTargetDAGCombine(ISD::SDIVREM); setTargetDAGCombine(ISD::UDIVREM); setTargetDAGCombine(ISD::SETCC); setTargetDAGCombine(ISD::AND); setTargetDAGCombine(ISD::OR); setMinFunctionAlignment(2); setStackPointerRegisterToSaveRestore(Mips::SP); computeRegisterProperties(); setExceptionPointerRegister(Mips::A0); setExceptionSelectorRegister(Mips::A1); } bool MipsTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const { MVT::SimpleValueType SVT = VT.getSimpleVT().SimpleTy; return SVT == MVT::i64 || SVT == MVT::i32 || SVT == MVT::i16; } EVT MipsTargetLowering::getSetCCResultType(EVT VT) const { return MVT::i32; } // SelectMadd - // Transforms a subgraph in CurDAG if the following pattern is found: // (addc multLo, Lo0), (adde multHi, Hi0), // where, // multHi/Lo: product of multiplication // Lo0: initial value of Lo register // Hi0: initial value of Hi register // Return true if pattern matching was successful. static bool SelectMadd(SDNode* ADDENode, SelectionDAG* CurDAG) { // ADDENode's second operand must be a flag output of an ADDC node in order // for the matching to be successful. SDNode* ADDCNode = ADDENode->getOperand(2).getNode(); if (ADDCNode->getOpcode() != ISD::ADDC) return false; SDValue MultHi = ADDENode->getOperand(0); SDValue MultLo = ADDCNode->getOperand(0); SDNode* MultNode = MultHi.getNode(); unsigned MultOpc = MultHi.getOpcode(); // MultHi and MultLo must be generated by the same node, if (MultLo.getNode() != MultNode) return false; // and it must be a multiplication. if (MultOpc != ISD::SMUL_LOHI && MultOpc != ISD::UMUL_LOHI) return false; // MultLo amd MultHi must be the first and second output of MultNode // respectively. if (MultHi.getResNo() != 1 || MultLo.getResNo() != 0) return false; // Transform this to a MADD only if ADDENode and ADDCNode are the only users // of the values of MultNode, in which case MultNode will be removed in later // phases. // If there exist users other than ADDENode or ADDCNode, this function returns // here, which will result in MultNode being mapped to a single MULT // instruction node rather than a pair of MULT and MADD instructions being // produced. if (!MultHi.hasOneUse() || !MultLo.hasOneUse()) return false; SDValue Chain = CurDAG->getEntryNode(); DebugLoc dl = ADDENode->getDebugLoc(); // create MipsMAdd(u) node MultOpc = MultOpc == ISD::UMUL_LOHI ? MipsISD::MAddu : MipsISD::MAdd; SDValue MAdd = CurDAG->getNode(MultOpc, dl, MVT::Glue, MultNode->getOperand(0),// Factor 0 MultNode->getOperand(1),// Factor 1 ADDCNode->getOperand(1),// Lo0 ADDENode->getOperand(1));// Hi0 // create CopyFromReg nodes SDValue CopyFromLo = CurDAG->getCopyFromReg(Chain, dl, Mips::LO, MVT::i32, MAdd); SDValue CopyFromHi = CurDAG->getCopyFromReg(CopyFromLo.getValue(1), dl, Mips::HI, MVT::i32, CopyFromLo.getValue(2)); // replace uses of adde and addc here if (!SDValue(ADDCNode, 0).use_empty()) CurDAG->ReplaceAllUsesOfValueWith(SDValue(ADDCNode, 0), CopyFromLo); if (!SDValue(ADDENode, 0).use_empty()) CurDAG->ReplaceAllUsesOfValueWith(SDValue(ADDENode, 0), CopyFromHi); return true; } // SelectMsub - // Transforms a subgraph in CurDAG if the following pattern is found: // (addc Lo0, multLo), (sube Hi0, multHi), // where, // multHi/Lo: product of multiplication // Lo0: initial value of Lo register // Hi0: initial value of Hi register // Return true if pattern matching was successful. static bool SelectMsub(SDNode* SUBENode, SelectionDAG* CurDAG) { // SUBENode's second operand must be a flag output of an SUBC node in order // for the matching to be successful. SDNode* SUBCNode = SUBENode->getOperand(2).getNode(); if (SUBCNode->getOpcode() != ISD::SUBC) return false; SDValue MultHi = SUBENode->getOperand(1); SDValue MultLo = SUBCNode->getOperand(1); SDNode* MultNode = MultHi.getNode(); unsigned MultOpc = MultHi.getOpcode(); // MultHi and MultLo must be generated by the same node, if (MultLo.getNode() != MultNode) return false; // and it must be a multiplication. if (MultOpc != ISD::SMUL_LOHI && MultOpc != ISD::UMUL_LOHI) return false; // MultLo amd MultHi must be the first and second output of MultNode // respectively. if (MultHi.getResNo() != 1 || MultLo.getResNo() != 0) return false; // Transform this to a MSUB only if SUBENode and SUBCNode are the only users // of the values of MultNode, in which case MultNode will be removed in later // phases. // If there exist users other than SUBENode or SUBCNode, this function returns // here, which will result in MultNode being mapped to a single MULT // instruction node rather than a pair of MULT and MSUB instructions being // produced. if (!MultHi.hasOneUse() || !MultLo.hasOneUse()) return false; SDValue Chain = CurDAG->getEntryNode(); DebugLoc dl = SUBENode->getDebugLoc(); // create MipsSub(u) node MultOpc = MultOpc == ISD::UMUL_LOHI ? MipsISD::MSubu : MipsISD::MSub; SDValue MSub = CurDAG->getNode(MultOpc, dl, MVT::Glue, MultNode->getOperand(0),// Factor 0 MultNode->getOperand(1),// Factor 1 SUBCNode->getOperand(0),// Lo0 SUBENode->getOperand(0));// Hi0 // create CopyFromReg nodes SDValue CopyFromLo = CurDAG->getCopyFromReg(Chain, dl, Mips::LO, MVT::i32, MSub); SDValue CopyFromHi = CurDAG->getCopyFromReg(CopyFromLo.getValue(1), dl, Mips::HI, MVT::i32, CopyFromLo.getValue(2)); // replace uses of sube and subc here if (!SDValue(SUBCNode, 0).use_empty()) CurDAG->ReplaceAllUsesOfValueWith(SDValue(SUBCNode, 0), CopyFromLo); if (!SDValue(SUBENode, 0).use_empty()) CurDAG->ReplaceAllUsesOfValueWith(SDValue(SUBENode, 0), CopyFromHi); return true; } static SDValue PerformADDECombine(SDNode *N, SelectionDAG& DAG, TargetLowering::DAGCombinerInfo &DCI, const MipsSubtarget* Subtarget) { if (DCI.isBeforeLegalize()) return SDValue(); if (Subtarget->hasMips32() && N->getValueType(0) == MVT::i32 && SelectMadd(N, &DAG)) return SDValue(N, 0); return SDValue(); } static SDValue PerformSUBECombine(SDNode *N, SelectionDAG& DAG, TargetLowering::DAGCombinerInfo &DCI, const MipsSubtarget* Subtarget) { if (DCI.isBeforeLegalize()) return SDValue(); if (Subtarget->hasMips32() && N->getValueType(0) == MVT::i32 && SelectMsub(N, &DAG)) return SDValue(N, 0); return SDValue(); } static SDValue PerformDivRemCombine(SDNode *N, SelectionDAG& DAG, TargetLowering::DAGCombinerInfo &DCI, const MipsSubtarget* Subtarget) { if (DCI.isBeforeLegalizeOps()) return SDValue(); EVT Ty = N->getValueType(0); unsigned LO = (Ty == MVT::i32) ? Mips::LO : Mips::LO64; unsigned HI = (Ty == MVT::i32) ? Mips::HI : Mips::HI64; unsigned opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem : MipsISD::DivRemU; DebugLoc dl = N->getDebugLoc(); SDValue DivRem = DAG.getNode(opc, dl, MVT::Glue, N->getOperand(0), N->getOperand(1)); SDValue InChain = DAG.getEntryNode(); SDValue InGlue = DivRem; // insert MFLO if (N->hasAnyUseOfValue(0)) { SDValue CopyFromLo = DAG.getCopyFromReg(InChain, dl, LO, Ty, InGlue); DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo); InChain = CopyFromLo.getValue(1); InGlue = CopyFromLo.getValue(2); } // insert MFHI if (N->hasAnyUseOfValue(1)) { SDValue CopyFromHi = DAG.getCopyFromReg(InChain, dl, HI, Ty, InGlue); DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi); } return SDValue(); } static Mips::CondCode FPCondCCodeToFCC(ISD::CondCode CC) { switch (CC) { default: llvm_unreachable("Unknown fp condition code!"); case ISD::SETEQ: case ISD::SETOEQ: return Mips::FCOND_OEQ; case ISD::SETUNE: return Mips::FCOND_UNE; case ISD::SETLT: case ISD::SETOLT: return Mips::FCOND_OLT; case ISD::SETGT: case ISD::SETOGT: return Mips::FCOND_OGT; case ISD::SETLE: case ISD::SETOLE: return Mips::FCOND_OLE; case ISD::SETGE: case ISD::SETOGE: return Mips::FCOND_OGE; case ISD::SETULT: return Mips::FCOND_ULT; case ISD::SETULE: return Mips::FCOND_ULE; case ISD::SETUGT: return Mips::FCOND_UGT; case ISD::SETUGE: return Mips::FCOND_UGE; case ISD::SETUO: return Mips::FCOND_UN; case ISD::SETO: return Mips::FCOND_OR; case ISD::SETNE: case ISD::SETONE: return Mips::FCOND_ONE; case ISD::SETUEQ: return Mips::FCOND_UEQ; } } // Returns true if condition code has to be inverted. static bool InvertFPCondCode(Mips::CondCode CC) { if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT) return false; if (CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) return true; assert(false && "Illegal Condition Code"); return false; } // Creates and returns an FPCmp node from a setcc node. // Returns Op if setcc is not a floating point comparison. static SDValue CreateFPCmp(SelectionDAG& DAG, const SDValue& Op) { // must be a SETCC node if (Op.getOpcode() != ISD::SETCC) return Op; SDValue LHS = Op.getOperand(0); if (!LHS.getValueType().isFloatingPoint()) return Op; SDValue RHS = Op.getOperand(1); DebugLoc dl = Op.getDebugLoc(); // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of // node if necessary. ISD::CondCode CC = cast(Op.getOperand(2))->get(); return DAG.getNode(MipsISD::FPCmp, dl, MVT::Glue, LHS, RHS, DAG.getConstant(FPCondCCodeToFCC(CC), MVT::i32)); } // Creates and returns a CMovFPT/F node. static SDValue CreateCMovFP(SelectionDAG& DAG, SDValue Cond, SDValue True, SDValue False, DebugLoc DL) { bool invert = InvertFPCondCode((Mips::CondCode) cast(Cond.getOperand(2)) ->getSExtValue()); return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL, True.getValueType(), True, False, Cond); } static SDValue PerformSETCCCombine(SDNode *N, SelectionDAG& DAG, TargetLowering::DAGCombinerInfo &DCI, const MipsSubtarget* Subtarget) { if (DCI.isBeforeLegalizeOps()) return SDValue(); SDValue Cond = CreateFPCmp(DAG, SDValue(N, 0)); if (Cond.getOpcode() != MipsISD::FPCmp) return SDValue(); SDValue True = DAG.getConstant(1, MVT::i32); SDValue False = DAG.getConstant(0, MVT::i32); return CreateCMovFP(DAG, Cond, True, False, N->getDebugLoc()); } static SDValue PerformANDCombine(SDNode *N, SelectionDAG& DAG, TargetLowering::DAGCombinerInfo &DCI, const MipsSubtarget* Subtarget) { // Pattern match EXT. // $dst = and ((sra or srl) $src , pos), (2**size - 1) // => ext $dst, $src, size, pos if (DCI.isBeforeLegalizeOps() || !Subtarget->hasMips32r2()) return SDValue(); SDValue ShiftRight = N->getOperand(0), Mask = N->getOperand(1); // Op's first operand must be a shift right. if (ShiftRight.getOpcode() != ISD::SRA && ShiftRight.getOpcode() != ISD::SRL) return SDValue(); // The second operand of the shift must be an immediate. uint64_t Pos; ConstantSDNode *CN; if (!(CN = dyn_cast(ShiftRight.getOperand(1)))) return SDValue(); Pos = CN->getZExtValue(); uint64_t SMPos, SMSize; // Op's second operand must be a shifted mask. if (!(CN = dyn_cast(Mask)) || !IsShiftedMask(CN->getZExtValue(), SMPos, SMSize)) return SDValue(); // Return if the shifted mask does not start at bit 0 or the sum of its size // and Pos exceeds the word's size. if (SMPos != 0 || Pos + SMSize > 32) return SDValue(); return DAG.getNode(MipsISD::Ext, N->getDebugLoc(), MVT::i32, ShiftRight.getOperand(0), DAG.getConstant(Pos, MVT::i32), DAG.getConstant(SMSize, MVT::i32)); } static SDValue PerformORCombine(SDNode *N, SelectionDAG& DAG, TargetLowering::DAGCombinerInfo &DCI, const MipsSubtarget* Subtarget) { // Pattern match INS. // $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1), // where mask1 = (2**size - 1) << pos, mask0 = ~mask1 // => ins $dst, $src, size, pos, $src1 if (DCI.isBeforeLegalizeOps() || !Subtarget->hasMips32r2()) return SDValue(); SDValue And0 = N->getOperand(0), And1 = N->getOperand(1); uint64_t SMPos0, SMSize0, SMPos1, SMSize1; ConstantSDNode *CN; // See if Op's first operand matches (and $src1 , mask0). if (And0.getOpcode() != ISD::AND) return SDValue(); if (!(CN = dyn_cast(And0.getOperand(1))) || !IsShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0)) return SDValue(); // See if Op's second operand matches (and (shl $src, pos), mask1). if (And1.getOpcode() != ISD::AND) return SDValue(); if (!(CN = dyn_cast(And1.getOperand(1))) || !IsShiftedMask(CN->getZExtValue(), SMPos1, SMSize1)) return SDValue(); // The shift masks must have the same position and size. if (SMPos0 != SMPos1 || SMSize0 != SMSize1) return SDValue(); SDValue Shl = And1.getOperand(0); if (Shl.getOpcode() != ISD::SHL) return SDValue(); if (!(CN = dyn_cast(Shl.getOperand(1)))) return SDValue(); unsigned Shamt = CN->getZExtValue(); // Return if the shift amount and the first bit position of mask are not the // same. if (Shamt != SMPos0) return SDValue(); return DAG.getNode(MipsISD::Ins, N->getDebugLoc(), MVT::i32, Shl.getOperand(0), DAG.getConstant(SMPos0, MVT::i32), DAG.getConstant(SMSize0, MVT::i32), And0.getOperand(0)); } SDValue MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const { SelectionDAG &DAG = DCI.DAG; unsigned opc = N->getOpcode(); switch (opc) { default: break; case ISD::ADDE: return PerformADDECombine(N, DAG, DCI, Subtarget); case ISD::SUBE: return PerformSUBECombine(N, DAG, DCI, Subtarget); case ISD::SDIVREM: case ISD::UDIVREM: return PerformDivRemCombine(N, DAG, DCI, Subtarget); case ISD::SETCC: return PerformSETCCCombine(N, DAG, DCI, Subtarget); case ISD::AND: return PerformANDCombine(N, DAG, DCI, Subtarget); case ISD::OR: return PerformORCombine(N, DAG, DCI, Subtarget); } return SDValue(); } SDValue MipsTargetLowering:: LowerOperation(SDValue Op, SelectionDAG &DAG) const { switch (Op.getOpcode()) { case ISD::BRCOND: return LowerBRCOND(Op, DAG); case ISD::ConstantPool: return LowerConstantPool(Op, DAG); case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG); case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG); case ISD::BlockAddress: return LowerBlockAddress(Op, DAG); case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG); case ISD::JumpTable: return LowerJumpTable(Op, DAG); case ISD::SELECT: return LowerSELECT(Op, DAG); case ISD::VASTART: return LowerVASTART(Op, DAG); case ISD::FCOPYSIGN: return LowerFCOPYSIGN(Op, DAG); case ISD::FRAMEADDR: return LowerFRAMEADDR(Op, DAG); case ISD::MEMBARRIER: return LowerMEMBARRIER(Op, DAG); case ISD::ATOMIC_FENCE: return LowerATOMIC_FENCE(Op, DAG); } return SDValue(); } //===----------------------------------------------------------------------===// // Lower helper functions //===----------------------------------------------------------------------===// // AddLiveIn - This helper function adds the specified physical register to the // MachineFunction as a live in value. It also creates a corresponding // virtual register for it. static unsigned AddLiveIn(MachineFunction &MF, unsigned PReg, TargetRegisterClass *RC) { assert(RC->contains(PReg) && "Not the correct regclass!"); unsigned VReg = MF.getRegInfo().createVirtualRegister(RC); MF.getRegInfo().addLiveIn(PReg, VReg); return VReg; } // Get fp branch code (not opcode) from condition code. static Mips::FPBranchCode GetFPBranchCodeFromCond(Mips::CondCode CC) { if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT) return Mips::BRANCH_T; if (CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) return Mips::BRANCH_F; return Mips::BRANCH_INVALID; } /* static MachineBasicBlock* ExpandCondMov(MachineInstr *MI, MachineBasicBlock *BB, DebugLoc dl, const MipsSubtarget* Subtarget, const TargetInstrInfo *TII, bool isFPCmp, unsigned Opc) { // There is no need to expand CMov instructions if target has // conditional moves. if (Subtarget->hasCondMov()) return BB; // To "insert" a SELECT_CC instruction, we actually have to insert the // diamond control-flow pattern. The incoming instruction knows the // destination vreg to set, the condition code register to branch on, the // true/false values to select between, and a branch opcode to use. const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineFunction::iterator It = BB; ++It; // thisMBB: // ... // TrueVal = ... // setcc r1, r2, r3 // bNE r1, r0, copy1MBB // fallthrough --> copy0MBB MachineBasicBlock *thisMBB = BB; MachineFunction *F = BB->getParent(); MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB); F->insert(It, copy0MBB); F->insert(It, sinkMBB); // Transfer the remainder of BB and its successor edges to sinkMBB. sinkMBB->splice(sinkMBB->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)), BB->end()); sinkMBB->transferSuccessorsAndUpdatePHIs(BB); // Next, add the true and fallthrough blocks as its successors. BB->addSuccessor(copy0MBB); BB->addSuccessor(sinkMBB); // Emit the right instruction according to the type of the operands compared if (isFPCmp) BuildMI(BB, dl, TII->get(Opc)).addMBB(sinkMBB); else BuildMI(BB, dl, TII->get(Opc)).addReg(MI->getOperand(2).getReg()) .addReg(Mips::ZERO).addMBB(sinkMBB); // copy0MBB: // %FalseValue = ... // # fallthrough to sinkMBB BB = copy0MBB; // Update machine-CFG edges BB->addSuccessor(sinkMBB); // sinkMBB: // %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ] // ... BB = sinkMBB; if (isFPCmp) BuildMI(*BB, BB->begin(), dl, TII->get(Mips::PHI), MI->getOperand(0).getReg()) .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB) .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB); else BuildMI(*BB, BB->begin(), dl, TII->get(Mips::PHI), MI->getOperand(0).getReg()) .addReg(MI->getOperand(3).getReg()).addMBB(thisMBB) .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB); MI->eraseFromParent(); // The pseudo instruction is gone now. return BB; } */ MachineBasicBlock * MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *BB) const { switch (MI->getOpcode()) { default: assert(false && "Unexpected instr type to insert"); return NULL; case Mips::ATOMIC_LOAD_ADD_I8: case Mips::ATOMIC_LOAD_ADD_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, Mips::ADDu); case Mips::ATOMIC_LOAD_ADD_I16: case Mips::ATOMIC_LOAD_ADD_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, Mips::ADDu); case Mips::ATOMIC_LOAD_ADD_I32: case Mips::ATOMIC_LOAD_ADD_I32_P8: return EmitAtomicBinary(MI, BB, 4, Mips::ADDu); case Mips::ATOMIC_LOAD_ADD_I64: case Mips::ATOMIC_LOAD_ADD_I64_P8: return EmitAtomicBinary(MI, BB, 8, Mips::DADDu); case Mips::ATOMIC_LOAD_AND_I8: case Mips::ATOMIC_LOAD_AND_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, Mips::AND); case Mips::ATOMIC_LOAD_AND_I16: case Mips::ATOMIC_LOAD_AND_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, Mips::AND); case Mips::ATOMIC_LOAD_AND_I32: case Mips::ATOMIC_LOAD_AND_I32_P8: return EmitAtomicBinary(MI, BB, 4, Mips::AND); case Mips::ATOMIC_LOAD_AND_I64: case Mips::ATOMIC_LOAD_AND_I64_P8: return EmitAtomicBinary(MI, BB, 8, Mips::AND64); case Mips::ATOMIC_LOAD_OR_I8: case Mips::ATOMIC_LOAD_OR_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, Mips::OR); case Mips::ATOMIC_LOAD_OR_I16: case Mips::ATOMIC_LOAD_OR_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, Mips::OR); case Mips::ATOMIC_LOAD_OR_I32: case Mips::ATOMIC_LOAD_OR_I32_P8: return EmitAtomicBinary(MI, BB, 4, Mips::OR); case Mips::ATOMIC_LOAD_OR_I64: case Mips::ATOMIC_LOAD_OR_I64_P8: return EmitAtomicBinary(MI, BB, 8, Mips::OR64); case Mips::ATOMIC_LOAD_XOR_I8: case Mips::ATOMIC_LOAD_XOR_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, Mips::XOR); case Mips::ATOMIC_LOAD_XOR_I16: case Mips::ATOMIC_LOAD_XOR_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, Mips::XOR); case Mips::ATOMIC_LOAD_XOR_I32: case Mips::ATOMIC_LOAD_XOR_I32_P8: return EmitAtomicBinary(MI, BB, 4, Mips::XOR); case Mips::ATOMIC_LOAD_XOR_I64: case Mips::ATOMIC_LOAD_XOR_I64_P8: return EmitAtomicBinary(MI, BB, 8, Mips::XOR64); case Mips::ATOMIC_LOAD_NAND_I8: case Mips::ATOMIC_LOAD_NAND_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, 0, true); case Mips::ATOMIC_LOAD_NAND_I16: case Mips::ATOMIC_LOAD_NAND_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, 0, true); case Mips::ATOMIC_LOAD_NAND_I32: case Mips::ATOMIC_LOAD_NAND_I32_P8: return EmitAtomicBinary(MI, BB, 4, 0, true); case Mips::ATOMIC_LOAD_NAND_I64: case Mips::ATOMIC_LOAD_NAND_I64_P8: return EmitAtomicBinary(MI, BB, 8, 0, true); case Mips::ATOMIC_LOAD_SUB_I8: case Mips::ATOMIC_LOAD_SUB_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, Mips::SUBu); case Mips::ATOMIC_LOAD_SUB_I16: case Mips::ATOMIC_LOAD_SUB_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, Mips::SUBu); case Mips::ATOMIC_LOAD_SUB_I32: case Mips::ATOMIC_LOAD_SUB_I32_P8: return EmitAtomicBinary(MI, BB, 4, Mips::SUBu); case Mips::ATOMIC_LOAD_SUB_I64: case Mips::ATOMIC_LOAD_SUB_I64_P8: return EmitAtomicBinary(MI, BB, 8, Mips::DSUBu); case Mips::ATOMIC_SWAP_I8: case Mips::ATOMIC_SWAP_I8_P8: return EmitAtomicBinaryPartword(MI, BB, 1, 0); case Mips::ATOMIC_SWAP_I16: case Mips::ATOMIC_SWAP_I16_P8: return EmitAtomicBinaryPartword(MI, BB, 2, 0); case Mips::ATOMIC_SWAP_I32: case Mips::ATOMIC_SWAP_I32_P8: return EmitAtomicBinary(MI, BB, 4, 0); case Mips::ATOMIC_SWAP_I64: case Mips::ATOMIC_SWAP_I64_P8: return EmitAtomicBinary(MI, BB, 8, 0); case Mips::ATOMIC_CMP_SWAP_I8: case Mips::ATOMIC_CMP_SWAP_I8_P8: return EmitAtomicCmpSwapPartword(MI, BB, 1); case Mips::ATOMIC_CMP_SWAP_I16: case Mips::ATOMIC_CMP_SWAP_I16_P8: return EmitAtomicCmpSwapPartword(MI, BB, 2); case Mips::ATOMIC_CMP_SWAP_I32: case Mips::ATOMIC_CMP_SWAP_I32_P8: return EmitAtomicCmpSwap(MI, BB, 4); case Mips::ATOMIC_CMP_SWAP_I64: case Mips::ATOMIC_CMP_SWAP_I64_P8: return EmitAtomicCmpSwap(MI, BB, 8); } } // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true) MachineBasicBlock * MipsTargetLowering::EmitAtomicBinary(MachineInstr *MI, MachineBasicBlock *BB, unsigned Size, unsigned BinOpcode, bool Nand) const { assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicBinary."); MachineFunction *MF = BB->getParent(); MachineRegisterInfo &RegInfo = MF->getRegInfo(); const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8)); const TargetInstrInfo *TII = getTargetMachine().getInstrInfo(); DebugLoc dl = MI->getDebugLoc(); unsigned LL, SC, AND, NOR, ZERO, BEQ; if (Size == 4) { LL = IsN64 ? Mips::LL_P8 : Mips::LL; SC = IsN64 ? Mips::SC_P8 : Mips::SC; AND = Mips::AND; NOR = Mips::NOR; ZERO = Mips::ZERO; BEQ = Mips::BEQ; } else { LL = IsN64 ? Mips::LLD_P8 : Mips::LLD; SC = IsN64 ? Mips::SCD_P8 : Mips::SCD; AND = Mips::AND64; NOR = Mips::NOR64; ZERO = Mips::ZERO_64; BEQ = Mips::BEQ64; } unsigned OldVal = MI->getOperand(0).getReg(); unsigned Ptr = MI->getOperand(1).getReg(); unsigned Incr = MI->getOperand(2).getReg(); unsigned StoreVal = RegInfo.createVirtualRegister(RC); unsigned AndRes = RegInfo.createVirtualRegister(RC); unsigned Success = RegInfo.createVirtualRegister(RC); // insert new blocks after the current block const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineFunction::iterator It = BB; ++It; MF->insert(It, loopMBB); MF->insert(It, exitMBB); // Transfer the remainder of BB and its successor edges to exitMBB. exitMBB->splice(exitMBB->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)), BB->end()); exitMBB->transferSuccessorsAndUpdatePHIs(BB); // thisMBB: // ... // fallthrough --> loopMBB BB->addSuccessor(loopMBB); loopMBB->addSuccessor(loopMBB); loopMBB->addSuccessor(exitMBB); // loopMBB: // ll oldval, 0(ptr) // storeval, oldval, incr // sc success, storeval, 0(ptr) // beq success, $0, loopMBB BB = loopMBB; BuildMI(BB, dl, TII->get(LL), OldVal).addReg(Ptr).addImm(0); if (Nand) { // and andres, oldval, incr // nor storeval, $0, andres BuildMI(BB, dl, TII->get(AND), AndRes).addReg(OldVal).addReg(Incr); BuildMI(BB, dl, TII->get(NOR), StoreVal).addReg(ZERO).addReg(AndRes); } else if (BinOpcode) { // storeval, oldval, incr BuildMI(BB, dl, TII->get(BinOpcode), StoreVal).addReg(OldVal).addReg(Incr); } else { StoreVal = Incr; } BuildMI(BB, dl, TII->get(SC), Success).addReg(StoreVal).addReg(Ptr).addImm(0); BuildMI(BB, dl, TII->get(BEQ)).addReg(Success).addReg(ZERO).addMBB(loopMBB); MI->eraseFromParent(); // The instruction is gone now. return exitMBB; } MachineBasicBlock * MipsTargetLowering::EmitAtomicBinaryPartword(MachineInstr *MI, MachineBasicBlock *BB, unsigned Size, unsigned BinOpcode, bool Nand) const { assert((Size == 1 || Size == 2) && "Unsupported size for EmitAtomicBinaryPartial."); MachineFunction *MF = BB->getParent(); MachineRegisterInfo &RegInfo = MF->getRegInfo(); const TargetRegisterClass *RC = getRegClassFor(MVT::i32); const TargetInstrInfo *TII = getTargetMachine().getInstrInfo(); DebugLoc dl = MI->getDebugLoc(); unsigned LL = IsN64 ? Mips::LL_P8 : Mips::LL; unsigned SC = IsN64 ? Mips::SC_P8 : Mips::SC; unsigned Dest = MI->getOperand(0).getReg(); unsigned Ptr = MI->getOperand(1).getReg(); unsigned Incr = MI->getOperand(2).getReg(); unsigned AlignedAddr = RegInfo.createVirtualRegister(RC); unsigned ShiftAmt = RegInfo.createVirtualRegister(RC); unsigned Mask = RegInfo.createVirtualRegister(RC); unsigned Mask2 = RegInfo.createVirtualRegister(RC); unsigned NewVal = RegInfo.createVirtualRegister(RC); unsigned OldVal = RegInfo.createVirtualRegister(RC); unsigned Incr2 = RegInfo.createVirtualRegister(RC); unsigned MaskLSB2 = RegInfo.createVirtualRegister(RC); unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC); unsigned MaskUpper = RegInfo.createVirtualRegister(RC); unsigned AndRes = RegInfo.createVirtualRegister(RC); unsigned BinOpRes = RegInfo.createVirtualRegister(RC); unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC); unsigned StoreVal = RegInfo.createVirtualRegister(RC); unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC); unsigned SrlRes = RegInfo.createVirtualRegister(RC); unsigned SllRes = RegInfo.createVirtualRegister(RC); unsigned Success = RegInfo.createVirtualRegister(RC); // insert new blocks after the current block const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineFunction::iterator It = BB; ++It; MF->insert(It, loopMBB); MF->insert(It, sinkMBB); MF->insert(It, exitMBB); // Transfer the remainder of BB and its successor edges to exitMBB. exitMBB->splice(exitMBB->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)), BB->end()); exitMBB->transferSuccessorsAndUpdatePHIs(BB); BB->addSuccessor(loopMBB); loopMBB->addSuccessor(loopMBB); loopMBB->addSuccessor(sinkMBB); sinkMBB->addSuccessor(exitMBB); // thisMBB: // addiu masklsb2,$0,-4 # 0xfffffffc // and alignedaddr,ptr,masklsb2 // andi ptrlsb2,ptr,3 // sll shiftamt,ptrlsb2,3 // ori maskupper,$0,255 # 0xff // sll mask,maskupper,shiftamt // nor mask2,$0,mask // sll incr2,incr,shiftamt int64_t MaskImm = (Size == 1) ? 255 : 65535; BuildMI(BB, dl, TII->get(Mips::ADDiu), MaskLSB2) .addReg(Mips::ZERO).addImm(-4); BuildMI(BB, dl, TII->get(Mips::AND), AlignedAddr) .addReg(Ptr).addReg(MaskLSB2); BuildMI(BB, dl, TII->get(Mips::ANDi), PtrLSB2).addReg(Ptr).addImm(3); BuildMI(BB, dl, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3); BuildMI(BB, dl, TII->get(Mips::ORi), MaskUpper) .addReg(Mips::ZERO).addImm(MaskImm); BuildMI(BB, dl, TII->get(Mips::SLLV), Mask) .addReg(ShiftAmt).addReg(MaskUpper); BuildMI(BB, dl, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask); BuildMI(BB, dl, TII->get(Mips::SLLV), Incr2).addReg(ShiftAmt).addReg(Incr); // atomic.load.binop // loopMBB: // ll oldval,0(alignedaddr) // binop binopres,oldval,incr2 // and newval,binopres,mask // and maskedoldval0,oldval,mask2 // or storeval,maskedoldval0,newval // sc success,storeval,0(alignedaddr) // beq success,$0,loopMBB // atomic.swap // loopMBB: // ll oldval,0(alignedaddr) // and newval,incr2,mask // and maskedoldval0,oldval,mask2 // or storeval,maskedoldval0,newval // sc success,storeval,0(alignedaddr) // beq success,$0,loopMBB BB = loopMBB; BuildMI(BB, dl, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0); if (Nand) { // and andres, oldval, incr2 // nor binopres, $0, andres // and newval, binopres, mask BuildMI(BB, dl, TII->get(Mips::AND), AndRes).addReg(OldVal).addReg(Incr2); BuildMI(BB, dl, TII->get(Mips::NOR), BinOpRes) .addReg(Mips::ZERO).addReg(AndRes); BuildMI(BB, dl, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask); } else if (BinOpcode) { // binopres, oldval, incr2 // and newval, binopres, mask BuildMI(BB, dl, TII->get(BinOpcode), BinOpRes).addReg(OldVal).addReg(Incr2); BuildMI(BB, dl, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask); } else {// atomic.swap // and newval, incr2, mask BuildMI(BB, dl, TII->get(Mips::AND), NewVal).addReg(Incr2).addReg(Mask); } BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal0) .addReg(OldVal).addReg(Mask2); BuildMI(BB, dl, TII->get(Mips::OR), StoreVal) .addReg(MaskedOldVal0).addReg(NewVal); BuildMI(BB, dl, TII->get(SC), Success) .addReg(StoreVal).addReg(AlignedAddr).addImm(0); BuildMI(BB, dl, TII->get(Mips::BEQ)) .addReg(Success).addReg(Mips::ZERO).addMBB(loopMBB); // sinkMBB: // and maskedoldval1,oldval,mask // srl srlres,maskedoldval1,shiftamt // sll sllres,srlres,24 // sra dest,sllres,24 BB = sinkMBB; int64_t ShiftImm = (Size == 1) ? 24 : 16; BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal1) .addReg(OldVal).addReg(Mask); BuildMI(BB, dl, TII->get(Mips::SRLV), SrlRes) .addReg(ShiftAmt).addReg(MaskedOldVal1); BuildMI(BB, dl, TII->get(Mips::SLL), SllRes) .addReg(SrlRes).addImm(ShiftImm); BuildMI(BB, dl, TII->get(Mips::SRA), Dest) .addReg(SllRes).addImm(ShiftImm); MI->eraseFromParent(); // The instruction is gone now. return exitMBB; } MachineBasicBlock * MipsTargetLowering::EmitAtomicCmpSwap(MachineInstr *MI, MachineBasicBlock *BB, unsigned Size) const { assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicCmpSwap."); MachineFunction *MF = BB->getParent(); MachineRegisterInfo &RegInfo = MF->getRegInfo(); const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8)); const TargetInstrInfo *TII = getTargetMachine().getInstrInfo(); DebugLoc dl = MI->getDebugLoc(); unsigned LL, SC, ZERO, BNE, BEQ; if (Size == 4) { LL = IsN64 ? Mips::LL_P8 : Mips::LL; SC = IsN64 ? Mips::SC_P8 : Mips::SC; ZERO = Mips::ZERO; BNE = Mips::BNE; BEQ = Mips::BEQ; } else { LL = IsN64 ? Mips::LLD_P8 : Mips::LLD; SC = IsN64 ? Mips::SCD_P8 : Mips::SCD; ZERO = Mips::ZERO_64; BNE = Mips::BNE64; BEQ = Mips::BEQ64; } unsigned Dest = MI->getOperand(0).getReg(); unsigned Ptr = MI->getOperand(1).getReg(); unsigned OldVal = MI->getOperand(2).getReg(); unsigned NewVal = MI->getOperand(3).getReg(); unsigned Success = RegInfo.createVirtualRegister(RC); // insert new blocks after the current block const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineFunction::iterator It = BB; ++It; MF->insert(It, loop1MBB); MF->insert(It, loop2MBB); MF->insert(It, exitMBB); // Transfer the remainder of BB and its successor edges to exitMBB. exitMBB->splice(exitMBB->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)), BB->end()); exitMBB->transferSuccessorsAndUpdatePHIs(BB); // thisMBB: // ... // fallthrough --> loop1MBB BB->addSuccessor(loop1MBB); loop1MBB->addSuccessor(exitMBB); loop1MBB->addSuccessor(loop2MBB); loop2MBB->addSuccessor(loop1MBB); loop2MBB->addSuccessor(exitMBB); // loop1MBB: // ll dest, 0(ptr) // bne dest, oldval, exitMBB BB = loop1MBB; BuildMI(BB, dl, TII->get(LL), Dest).addReg(Ptr).addImm(0); BuildMI(BB, dl, TII->get(BNE)) .addReg(Dest).addReg(OldVal).addMBB(exitMBB); // loop2MBB: // sc success, newval, 0(ptr) // beq success, $0, loop1MBB BB = loop2MBB; BuildMI(BB, dl, TII->get(SC), Success) .addReg(NewVal).addReg(Ptr).addImm(0); BuildMI(BB, dl, TII->get(BEQ)) .addReg(Success).addReg(ZERO).addMBB(loop1MBB); MI->eraseFromParent(); // The instruction is gone now. return exitMBB; } MachineBasicBlock * MipsTargetLowering::EmitAtomicCmpSwapPartword(MachineInstr *MI, MachineBasicBlock *BB, unsigned Size) const { assert((Size == 1 || Size == 2) && "Unsupported size for EmitAtomicCmpSwapPartial."); MachineFunction *MF = BB->getParent(); MachineRegisterInfo &RegInfo = MF->getRegInfo(); const TargetRegisterClass *RC = getRegClassFor(MVT::i32); const TargetInstrInfo *TII = getTargetMachine().getInstrInfo(); DebugLoc dl = MI->getDebugLoc(); unsigned LL = IsN64 ? Mips::LL_P8 : Mips::LL; unsigned SC = IsN64 ? Mips::SC_P8 : Mips::SC; unsigned Dest = MI->getOperand(0).getReg(); unsigned Ptr = MI->getOperand(1).getReg(); unsigned CmpVal = MI->getOperand(2).getReg(); unsigned NewVal = MI->getOperand(3).getReg(); unsigned AlignedAddr = RegInfo.createVirtualRegister(RC); unsigned ShiftAmt = RegInfo.createVirtualRegister(RC); unsigned Mask = RegInfo.createVirtualRegister(RC); unsigned Mask2 = RegInfo.createVirtualRegister(RC); unsigned ShiftedCmpVal = RegInfo.createVirtualRegister(RC); unsigned OldVal = RegInfo.createVirtualRegister(RC); unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC); unsigned ShiftedNewVal = RegInfo.createVirtualRegister(RC); unsigned MaskLSB2 = RegInfo.createVirtualRegister(RC); unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC); unsigned MaskUpper = RegInfo.createVirtualRegister(RC); unsigned MaskedCmpVal = RegInfo.createVirtualRegister(RC); unsigned MaskedNewVal = RegInfo.createVirtualRegister(RC); unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC); unsigned StoreVal = RegInfo.createVirtualRegister(RC); unsigned SrlRes = RegInfo.createVirtualRegister(RC); unsigned SllRes = RegInfo.createVirtualRegister(RC); unsigned Success = RegInfo.createVirtualRegister(RC); // insert new blocks after the current block const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB); MachineFunction::iterator It = BB; ++It; MF->insert(It, loop1MBB); MF->insert(It, loop2MBB); MF->insert(It, sinkMBB); MF->insert(It, exitMBB); // Transfer the remainder of BB and its successor edges to exitMBB. exitMBB->splice(exitMBB->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)), BB->end()); exitMBB->transferSuccessorsAndUpdatePHIs(BB); BB->addSuccessor(loop1MBB); loop1MBB->addSuccessor(sinkMBB); loop1MBB->addSuccessor(loop2MBB); loop2MBB->addSuccessor(loop1MBB); loop2MBB->addSuccessor(sinkMBB); sinkMBB->addSuccessor(exitMBB); // FIXME: computation of newval2 can be moved to loop2MBB. // thisMBB: // addiu masklsb2,$0,-4 # 0xfffffffc // and alignedaddr,ptr,masklsb2 // andi ptrlsb2,ptr,3 // sll shiftamt,ptrlsb2,3 // ori maskupper,$0,255 # 0xff // sll mask,maskupper,shiftamt // nor mask2,$0,mask // andi maskedcmpval,cmpval,255 // sll shiftedcmpval,maskedcmpval,shiftamt // andi maskednewval,newval,255 // sll shiftednewval,maskednewval,shiftamt int64_t MaskImm = (Size == 1) ? 255 : 65535; BuildMI(BB, dl, TII->get(Mips::ADDiu), MaskLSB2) .addReg(Mips::ZERO).addImm(-4); BuildMI(BB, dl, TII->get(Mips::AND), AlignedAddr) .addReg(Ptr).addReg(MaskLSB2); BuildMI(BB, dl, TII->get(Mips::ANDi), PtrLSB2).addReg(Ptr).addImm(3); BuildMI(BB, dl, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3); BuildMI(BB, dl, TII->get(Mips::ORi), MaskUpper) .addReg(Mips::ZERO).addImm(MaskImm); BuildMI(BB, dl, TII->get(Mips::SLLV), Mask) .addReg(ShiftAmt).addReg(MaskUpper); BuildMI(BB, dl, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask); BuildMI(BB, dl, TII->get(Mips::ANDi), MaskedCmpVal) .addReg(CmpVal).addImm(MaskImm); BuildMI(BB, dl, TII->get(Mips::SLLV), ShiftedCmpVal) .addReg(ShiftAmt).addReg(MaskedCmpVal); BuildMI(BB, dl, TII->get(Mips::ANDi), MaskedNewVal) .addReg(NewVal).addImm(MaskImm); BuildMI(BB, dl, TII->get(Mips::SLLV), ShiftedNewVal) .addReg(ShiftAmt).addReg(MaskedNewVal); // loop1MBB: // ll oldval,0(alginedaddr) // and maskedoldval0,oldval,mask // bne maskedoldval0,shiftedcmpval,sinkMBB BB = loop1MBB; BuildMI(BB, dl, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0); BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal0) .addReg(OldVal).addReg(Mask); BuildMI(BB, dl, TII->get(Mips::BNE)) .addReg(MaskedOldVal0).addReg(ShiftedCmpVal).addMBB(sinkMBB); // loop2MBB: // and maskedoldval1,oldval,mask2 // or storeval,maskedoldval1,shiftednewval // sc success,storeval,0(alignedaddr) // beq success,$0,loop1MBB BB = loop2MBB; BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal1) .addReg(OldVal).addReg(Mask2); BuildMI(BB, dl, TII->get(Mips::OR), StoreVal) .addReg(MaskedOldVal1).addReg(ShiftedNewVal); BuildMI(BB, dl, TII->get(SC), Success) .addReg(StoreVal).addReg(AlignedAddr).addImm(0); BuildMI(BB, dl, TII->get(Mips::BEQ)) .addReg(Success).addReg(Mips::ZERO).addMBB(loop1MBB); // sinkMBB: // srl srlres,maskedoldval0,shiftamt // sll sllres,srlres,24 // sra dest,sllres,24 BB = sinkMBB; int64_t ShiftImm = (Size == 1) ? 24 : 16; BuildMI(BB, dl, TII->get(Mips::SRLV), SrlRes) .addReg(ShiftAmt).addReg(MaskedOldVal0); BuildMI(BB, dl, TII->get(Mips::SLL), SllRes) .addReg(SrlRes).addImm(ShiftImm); BuildMI(BB, dl, TII->get(Mips::SRA), Dest) .addReg(SllRes).addImm(ShiftImm); MI->eraseFromParent(); // The instruction is gone now. return exitMBB; } //===----------------------------------------------------------------------===// // Misc Lower Operation implementation //===----------------------------------------------------------------------===// SDValue MipsTargetLowering:: LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const { MachineFunction &MF = DAG.getMachineFunction(); MipsFunctionInfo *MipsFI = MF.getInfo(); unsigned SP = IsN64 ? Mips::SP_64 : Mips::SP; assert(getTargetMachine().getFrameLowering()->getStackAlignment() >= cast(Op.getOperand(2).getNode())->getZExtValue() && "Cannot lower if the alignment of the allocated space is larger than \ that of the stack."); SDValue Chain = Op.getOperand(0); SDValue Size = Op.getOperand(1); DebugLoc dl = Op.getDebugLoc(); // Get a reference from Mips stack pointer SDValue StackPointer = DAG.getCopyFromReg(Chain, dl, SP, getPointerTy()); // Subtract the dynamic size from the actual stack size to // obtain the new stack size. SDValue Sub = DAG.getNode(ISD::SUB, dl, getPointerTy(), StackPointer, Size); // The Sub result contains the new stack start address, so it // must be placed in the stack pointer register. Chain = DAG.getCopyToReg(StackPointer.getValue(1), dl, SP, Sub, SDValue()); // This node always has two return values: a new stack pointer // value and a chain SDVTList VTLs = DAG.getVTList(getPointerTy(), MVT::Other); SDValue Ptr = DAG.getFrameIndex(MipsFI->getDynAllocFI(), getPointerTy()); SDValue Ops[] = { Chain, Ptr, Chain.getValue(1) }; return DAG.getNode(MipsISD::DynAlloc, dl, VTLs, Ops, 3); } SDValue MipsTargetLowering:: LowerBRCOND(SDValue Op, SelectionDAG &DAG) const { // The first operand is the chain, the second is the condition, the third is // the block to branch to if the condition is true. SDValue Chain = Op.getOperand(0); SDValue Dest = Op.getOperand(2); DebugLoc dl = Op.getDebugLoc(); SDValue CondRes = CreateFPCmp(DAG, Op.getOperand(1)); // Return if flag is not set by a floating point comparison. if (CondRes.getOpcode() != MipsISD::FPCmp) return Op; SDValue CCNode = CondRes.getOperand(2); Mips::CondCode CC = (Mips::CondCode)cast(CCNode)->getZExtValue(); SDValue BrCode = DAG.getConstant(GetFPBranchCodeFromCond(CC), MVT::i32); return DAG.getNode(MipsISD::FPBrcond, dl, Op.getValueType(), Chain, BrCode, Dest, CondRes); } SDValue MipsTargetLowering:: LowerSELECT(SDValue Op, SelectionDAG &DAG) const { SDValue Cond = CreateFPCmp(DAG, Op.getOperand(0)); // Return if flag is not set by a floating point comparison. if (Cond.getOpcode() != MipsISD::FPCmp) return Op; return CreateCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2), Op.getDebugLoc()); } SDValue MipsTargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const { // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); const GlobalValue *GV = cast(Op)->getGlobal(); if (getTargetMachine().getRelocationModel() != Reloc::PIC_ && !IsN64) { SDVTList VTs = DAG.getVTList(MVT::i32); MipsTargetObjectFile &TLOF = (MipsTargetObjectFile&)getObjFileLowering(); // %gp_rel relocation if (TLOF.IsGlobalInSmallSection(GV, getTargetMachine())) { SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_GPREL); SDValue GPRelNode = DAG.getNode(MipsISD::GPRel, dl, VTs, &GA, 1); SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(MVT::i32); return DAG.getNode(ISD::ADD, dl, MVT::i32, GOT, GPRelNode); } // %hi/%lo relocation SDValue GAHi = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_ABS_HI); SDValue GALo = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_ABS_LO); SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, VTs, &GAHi, 1); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GALo); return DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); } EVT ValTy = Op.getValueType(); bool HasGotOfst = (GV->hasInternalLinkage() || (GV->hasLocalLinkage() && !isa(GV))); unsigned GotFlag = IsN64 ? (HasGotOfst ? MipsII::MO_GOT_PAGE : MipsII::MO_GOT_DISP) : MipsII::MO_GOT; SDValue GA = DAG.getTargetGlobalAddress(GV, dl, ValTy, 0, GotFlag); GA = DAG.getNode(MipsISD::WrapperPIC, dl, ValTy, GA); SDValue ResNode = DAG.getLoad(ValTy, dl, DAG.getEntryNode(), GA, MachinePointerInfo(), false, false, false, 0); // On functions and global targets not internal linked only // a load from got/GP is necessary for PIC to work. if (!HasGotOfst) return ResNode; SDValue GALo = DAG.getTargetGlobalAddress(GV, dl, ValTy, 0, IsN64 ? MipsII::MO_GOT_OFST : MipsII::MO_ABS_LO); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, ValTy, GALo); return DAG.getNode(ISD::ADD, dl, ValTy, ResNode, Lo); } SDValue MipsTargetLowering::LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const { const BlockAddress *BA = cast(Op)->getBlockAddress(); // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); if (getTargetMachine().getRelocationModel() != Reloc::PIC_) { // %hi/%lo relocation SDValue BAHi = DAG.getBlockAddress(BA, MVT::i32, true, MipsII::MO_ABS_HI); SDValue BALo = DAG.getBlockAddress(BA, MVT::i32, true, MipsII::MO_ABS_LO); SDValue Hi = DAG.getNode(MipsISD::Hi, dl, MVT::i32, BAHi); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, BALo); return DAG.getNode(ISD::ADD, dl, MVT::i32, Hi, Lo); } SDValue BAGOTOffset = DAG.getBlockAddress(BA, MVT::i32, true, MipsII::MO_GOT); BAGOTOffset = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, BAGOTOffset); SDValue BALOOffset = DAG.getBlockAddress(BA, MVT::i32, true, MipsII::MO_ABS_LO); SDValue Load = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), BAGOTOffset, MachinePointerInfo(), false, false, false, 0); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, BALOOffset); return DAG.getNode(ISD::ADD, dl, MVT::i32, Load, Lo); } SDValue MipsTargetLowering:: LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const { // If the relocation model is PIC, use the General Dynamic TLS Model, // otherwise use the Initial Exec or Local Exec TLS Model. // TODO: implement Local Dynamic TLS model GlobalAddressSDNode *GA = cast(Op); DebugLoc dl = GA->getDebugLoc(); const GlobalValue *GV = GA->getGlobal(); EVT PtrVT = getPointerTy(); if (getTargetMachine().getRelocationModel() == Reloc::PIC_) { // General Dynamic TLS Model SDValue TGA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_TLSGD); SDValue Tlsgd = DAG.getNode(MipsISD::TlsGd, dl, MVT::i32, TGA); SDValue GP = DAG.getRegister(Mips::GP, MVT::i32); SDValue Argument = DAG.getNode(ISD::ADD, dl, MVT::i32, GP, Tlsgd); ArgListTy Args; ArgListEntry Entry; Entry.Node = Argument; Entry.Ty = (Type *) Type::getInt32Ty(*DAG.getContext()); Args.push_back(Entry); std::pair CallResult = LowerCallTo(DAG.getEntryNode(), (Type *) Type::getInt32Ty(*DAG.getContext()), false, false, false, false, 0, CallingConv::C, false, true, DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG, dl); return CallResult.first; } SDValue Offset; if (GV->isDeclaration()) { // Initial Exec TLS Model SDValue TGA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_GOTTPREL); Offset = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), TGA, MachinePointerInfo(), false, false, false, 0); } else { // Local Exec TLS Model SDVTList VTs = DAG.getVTList(MVT::i32); SDValue TGAHi = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_TPREL_HI); SDValue TGALo = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_TPREL_LO); SDValue Hi = DAG.getNode(MipsISD::TprelHi, dl, VTs, &TGAHi, 1); SDValue Lo = DAG.getNode(MipsISD::TprelLo, dl, MVT::i32, TGALo); Offset = DAG.getNode(ISD::ADD, dl, MVT::i32, Hi, Lo); } SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, dl, PtrVT); return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset); } SDValue MipsTargetLowering:: LowerJumpTable(SDValue Op, SelectionDAG &DAG) const { SDValue ResNode; SDValue HiPart; // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_; unsigned char OpFlag = IsPIC ? MipsII::MO_GOT : MipsII::MO_ABS_HI; EVT PtrVT = Op.getValueType(); JumpTableSDNode *JT = cast(Op); SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, OpFlag); if (!IsPIC) { SDValue Ops[] = { JTI }; HiPart = DAG.getNode(MipsISD::Hi, dl, DAG.getVTList(MVT::i32), Ops, 1); } else {// Emit Load from Global Pointer JTI = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, JTI); HiPart = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), JTI, MachinePointerInfo(), false, false, false, 0); } SDValue JTILo = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, MipsII::MO_ABS_LO); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, JTILo); ResNode = DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); return ResNode; } SDValue MipsTargetLowering:: LowerConstantPool(SDValue Op, SelectionDAG &DAG) const { SDValue ResNode; ConstantPoolSDNode *N = cast(Op); const Constant *C = N->getConstVal(); // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); // gp_rel relocation // FIXME: we should reference the constant pool using small data sections, // but the asm printer currently doesn't support this feature without // hacking it. This feature should come soon so we can uncomment the // stuff below. //if (IsInSmallSection(C->getType())) { // SDValue GPRelNode = DAG.getNode(MipsISD::GPRel, MVT::i32, CP); // SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(MVT::i32); // ResNode = DAG.getNode(ISD::ADD, MVT::i32, GOT, GPRelNode); if (getTargetMachine().getRelocationModel() != Reloc::PIC_) { SDValue CPHi = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MipsII::MO_ABS_HI); SDValue CPLo = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MipsII::MO_ABS_LO); SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, MVT::i32, CPHi); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, CPLo); ResNode = DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); } else { SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MipsII::MO_GOT); CP = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, CP); SDValue Load = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), CP, MachinePointerInfo::getConstantPool(), false, false, false, 0); SDValue CPLo = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MipsII::MO_ABS_LO); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, CPLo); ResNode = DAG.getNode(ISD::ADD, dl, MVT::i32, Load, Lo); } return ResNode; } SDValue MipsTargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG) const { MachineFunction &MF = DAG.getMachineFunction(); MipsFunctionInfo *FuncInfo = MF.getInfo(); DebugLoc dl = Op.getDebugLoc(); SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), getPointerTy()); // vastart just stores the address of the VarArgsFrameIndex slot into the // memory location argument. const Value *SV = cast(Op.getOperand(2))->getValue(); return DAG.getStore(Op.getOperand(0), dl, FI, Op.getOperand(1), MachinePointerInfo(SV), false, false, 0); } static SDValue LowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG) { // FIXME: Use ext/ins instructions if target architecture is Mips32r2. DebugLoc dl = Op.getDebugLoc(); SDValue Op0 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op.getOperand(0)); SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op.getOperand(1)); SDValue And0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op0, DAG.getConstant(0x7fffffff, MVT::i32)); SDValue And1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op1, DAG.getConstant(0x80000000, MVT::i32)); SDValue Result = DAG.getNode(ISD::OR, dl, MVT::i32, And0, And1); return DAG.getNode(ISD::BITCAST, dl, MVT::f32, Result); } static SDValue LowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG, bool isLittle) { // FIXME: // Use ext/ins instructions if target architecture is Mips32r2. // Eliminate redundant mfc1 and mtc1 instructions. unsigned LoIdx = 0, HiIdx = 1; if (!isLittle) std::swap(LoIdx, HiIdx); DebugLoc dl = Op.getDebugLoc(); SDValue Word0 = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32, Op.getOperand(0), DAG.getConstant(LoIdx, MVT::i32)); SDValue Hi0 = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32, Op.getOperand(0), DAG.getConstant(HiIdx, MVT::i32)); SDValue Hi1 = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32, Op.getOperand(1), DAG.getConstant(HiIdx, MVT::i32)); SDValue And0 = DAG.getNode(ISD::AND, dl, MVT::i32, Hi0, DAG.getConstant(0x7fffffff, MVT::i32)); SDValue And1 = DAG.getNode(ISD::AND, dl, MVT::i32, Hi1, DAG.getConstant(0x80000000, MVT::i32)); SDValue Word1 = DAG.getNode(ISD::OR, dl, MVT::i32, And0, And1); if (!isLittle) std::swap(Word0, Word1); return DAG.getNode(MipsISD::BuildPairF64, dl, MVT::f64, Word0, Word1); } SDValue MipsTargetLowering::LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const { EVT Ty = Op.getValueType(); assert(Ty == MVT::f32 || Ty == MVT::f64); if (Ty == MVT::f32) return LowerFCOPYSIGN32(Op, DAG); else return LowerFCOPYSIGN64(Op, DAG, Subtarget->isLittle()); } SDValue MipsTargetLowering:: LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const { // check the depth assert((cast(Op.getOperand(0))->getZExtValue() == 0) && "Frame address can only be determined for current frame."); MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo(); MFI->setFrameAddressIsTaken(true); EVT VT = Op.getValueType(); DebugLoc dl = Op.getDebugLoc(); SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, IsN64 ? Mips::FP_64 : Mips::FP, VT); return FrameAddr; } // TODO: set SType according to the desired memory barrier behavior. SDValue MipsTargetLowering::LowerMEMBARRIER(SDValue Op, SelectionDAG& DAG) const { unsigned SType = 0; DebugLoc dl = Op.getDebugLoc(); return DAG.getNode(MipsISD::Sync, dl, MVT::Other, Op.getOperand(0), DAG.getConstant(SType, MVT::i32)); } SDValue MipsTargetLowering::LowerATOMIC_FENCE(SDValue Op, SelectionDAG& DAG) const { // FIXME: Need pseudo-fence for 'singlethread' fences // FIXME: Set SType for weaker fences where supported/appropriate. unsigned SType = 0; DebugLoc dl = Op.getDebugLoc(); return DAG.getNode(MipsISD::Sync, dl, MVT::Other, Op.getOperand(0), DAG.getConstant(SType, MVT::i32)); } //===----------------------------------------------------------------------===// // Calling Convention Implementation //===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===// // TODO: Implement a generic logic using tblgen that can support this. // Mips O32 ABI rules: // --- // i32 - Passed in A0, A1, A2, A3 and stack // f32 - Only passed in f32 registers if no int reg has been used yet to hold // an argument. Otherwise, passed in A1, A2, A3 and stack. // f64 - Only passed in two aliased f32 registers if no int reg has been used // yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is // not used, it must be shadowed. If only A3 is avaiable, shadow it and // go to stack. // // For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack. //===----------------------------------------------------------------------===// static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) { static const unsigned IntRegsSize=4, FloatRegsSize=2; static const unsigned IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 }; static const unsigned F32Regs[] = { Mips::F12, Mips::F14 }; static const unsigned F64Regs[] = { Mips::D6, Mips::D7 }; // ByVal Args if (ArgFlags.isByVal()) { State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, 1 /*MinSize*/, 4 /*MinAlign*/, ArgFlags); unsigned NextReg = (State.getNextStackOffset() + 3) / 4; for (unsigned r = State.getFirstUnallocated(IntRegs, IntRegsSize); r < std::min(IntRegsSize, NextReg); ++r) State.AllocateReg(IntRegs[r]); return false; } // Promote i8 and i16 if (LocVT == MVT::i8 || LocVT == MVT::i16) { LocVT = MVT::i32; if (ArgFlags.isSExt()) LocInfo = CCValAssign::SExt; else if (ArgFlags.isZExt()) LocInfo = CCValAssign::ZExt; else LocInfo = CCValAssign::AExt; } unsigned Reg; // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following // is true: function is vararg, argument is 3rd or higher, there is previous // argument which is not f32 or f64. bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 || State.getFirstUnallocated(F32Regs, FloatRegsSize) != ValNo; unsigned OrigAlign = ArgFlags.getOrigAlign(); bool isI64 = (ValVT == MVT::i32 && OrigAlign == 8); if (ValVT == MVT::i32 || (ValVT == MVT::f32 && AllocateFloatsInIntReg)) { Reg = State.AllocateReg(IntRegs, IntRegsSize); // If this is the first part of an i64 arg, // the allocated register must be either A0 or A2. if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3)) Reg = State.AllocateReg(IntRegs, IntRegsSize); LocVT = MVT::i32; } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) { // Allocate int register and shadow next int register. If first // available register is Mips::A1 or Mips::A3, shadow it too. Reg = State.AllocateReg(IntRegs, IntRegsSize); if (Reg == Mips::A1 || Reg == Mips::A3) Reg = State.AllocateReg(IntRegs, IntRegsSize); State.AllocateReg(IntRegs, IntRegsSize); LocVT = MVT::i32; } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) { // we are guaranteed to find an available float register if (ValVT == MVT::f32) { Reg = State.AllocateReg(F32Regs, FloatRegsSize); // Shadow int register State.AllocateReg(IntRegs, IntRegsSize); } else { Reg = State.AllocateReg(F64Regs, FloatRegsSize); // Shadow int registers unsigned Reg2 = State.AllocateReg(IntRegs, IntRegsSize); if (Reg2 == Mips::A1 || Reg2 == Mips::A3) State.AllocateReg(IntRegs, IntRegsSize); State.AllocateReg(IntRegs, IntRegsSize); } } else llvm_unreachable("Cannot handle this ValVT."); unsigned SizeInBytes = ValVT.getSizeInBits() >> 3; unsigned Offset = State.AllocateStack(SizeInBytes, OrigAlign); if (!Reg) State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo)); else State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo)); return false; // CC must always match } static const unsigned Mips64IntRegs[8] = {Mips::A0_64, Mips::A1_64, Mips::A2_64, Mips::A3_64, Mips::T0_64, Mips::T1_64, Mips::T2_64, Mips::T3_64}; static const unsigned Mips64DPRegs[8] = {Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64, Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64}; static bool CC_Mips64Byval(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) { unsigned Align = std::max(ArgFlags.getByValAlign(), (unsigned)8); unsigned Size = (ArgFlags.getByValSize() + 7) / 8 * 8; unsigned FirstIdx = State.getFirstUnallocated(Mips64IntRegs, 8); assert(Align <= 16 && "Cannot handle alignments larger than 16."); // If byval is 16-byte aligned, the first arg register must be even. if ((Align == 16) && (FirstIdx % 2)) { State.AllocateReg(Mips64IntRegs[FirstIdx], Mips64DPRegs[FirstIdx]); ++FirstIdx; } // Mark the registers allocated. for (unsigned I = FirstIdx; Size && (I < 8); Size -= 8, ++I) State.AllocateReg(Mips64IntRegs[I], Mips64DPRegs[I]); // Allocate space on caller's stack. unsigned Offset = State.AllocateStack(Size, Align); if (FirstIdx < 8) State.addLoc(CCValAssign::getReg(ValNo, ValVT, Mips64IntRegs[FirstIdx], LocVT, LocInfo)); else State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo)); return true; } #include "MipsGenCallingConv.inc" static void AnalyzeMips64CallOperands(CCState CCInfo, const SmallVectorImpl &Outs) { unsigned NumOps = Outs.size(); for (unsigned i = 0; i != NumOps; ++i) { MVT ArgVT = Outs[i].VT; ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; bool R; if (Outs[i].IsFixed) R = CC_MipsN(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo); else R = CC_MipsN_VarArg(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo); if (R) { #ifndef NDEBUG dbgs() << "Call operand #" << i << " has unhandled type " << EVT(ArgVT).getEVTString(); #endif llvm_unreachable(0); } } } //===----------------------------------------------------------------------===// // Call Calling Convention Implementation //===----------------------------------------------------------------------===// static const unsigned O32IntRegsSize = 4; static const unsigned O32IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 }; // Return next O32 integer argument register. static unsigned getNextIntArgReg(unsigned Reg) { assert((Reg == Mips::A0) || (Reg == Mips::A2)); return (Reg == Mips::A0) ? Mips::A1 : Mips::A3; } // Write ByVal Arg to arg registers and stack. static void WriteByValArg(SDValue& ByValChain, SDValue Chain, DebugLoc dl, SmallVector, 16>& RegsToPass, SmallVector& MemOpChains, int& LastFI, MachineFrameInfo *MFI, SelectionDAG &DAG, SDValue Arg, const CCValAssign &VA, const ISD::ArgFlagsTy& Flags, MVT PtrType, bool isLittle) { unsigned LocMemOffset = VA.getLocMemOffset(); unsigned Offset = 0; uint32_t RemainingSize = Flags.getByValSize(); unsigned ByValAlign = Flags.getByValAlign(); // Copy the first 4 words of byval arg to registers A0 - A3. // FIXME: Use a stricter alignment if it enables better optimization in passes // run later. for (; RemainingSize >= 4 && LocMemOffset < 4 * 4; Offset += 4, RemainingSize -= 4, LocMemOffset += 4) { SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg, DAG.getConstant(Offset, MVT::i32)); SDValue LoadVal = DAG.getLoad(MVT::i32, dl, Chain, LoadPtr, MachinePointerInfo(), false, false, false, std::min(ByValAlign, (unsigned )4)); MemOpChains.push_back(LoadVal.getValue(1)); unsigned DstReg = O32IntRegs[LocMemOffset / 4]; RegsToPass.push_back(std::make_pair(DstReg, LoadVal)); } if (RemainingSize == 0) return; // If there still is a register available for argument passing, write the // remaining part of the structure to it using subword loads and shifts. if (LocMemOffset < 4 * 4) { assert(RemainingSize <= 3 && RemainingSize >= 1 && "There must be one to three bytes remaining."); unsigned LoadSize = (RemainingSize == 3 ? 2 : RemainingSize); SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg, DAG.getConstant(Offset, MVT::i32)); unsigned Alignment = std::min(ByValAlign, (unsigned )4); SDValue LoadVal = DAG.getExtLoad(ISD::ZEXTLOAD, dl, MVT::i32, Chain, LoadPtr, MachinePointerInfo(), MVT::getIntegerVT(LoadSize * 8), false, false, Alignment); MemOpChains.push_back(LoadVal.getValue(1)); // If target is big endian, shift it to the most significant half-word or // byte. if (!isLittle) LoadVal = DAG.getNode(ISD::SHL, dl, MVT::i32, LoadVal, DAG.getConstant(32 - LoadSize * 8, MVT::i32)); Offset += LoadSize; RemainingSize -= LoadSize; // Read second subword if necessary. if (RemainingSize != 0) { assert(RemainingSize == 1 && "There must be one byte remaining."); LoadPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg, DAG.getConstant(Offset, MVT::i32)); unsigned Alignment = std::min(ByValAlign, (unsigned )2); SDValue Subword = DAG.getExtLoad(ISD::ZEXTLOAD, dl, MVT::i32, Chain, LoadPtr, MachinePointerInfo(), MVT::i8, false, false, Alignment); MemOpChains.push_back(Subword.getValue(1)); // Insert the loaded byte to LoadVal. // FIXME: Use INS if supported by target. unsigned ShiftAmt = isLittle ? 16 : 8; SDValue Shift = DAG.getNode(ISD::SHL, dl, MVT::i32, Subword, DAG.getConstant(ShiftAmt, MVT::i32)); LoadVal = DAG.getNode(ISD::OR, dl, MVT::i32, LoadVal, Shift); } unsigned DstReg = O32IntRegs[LocMemOffset / 4]; RegsToPass.push_back(std::make_pair(DstReg, LoadVal)); return; } // Create a fixed object on stack at offset LocMemOffset and copy // remaining part of byval arg to it using memcpy. SDValue Src = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg, DAG.getConstant(Offset, MVT::i32)); LastFI = MFI->CreateFixedObject(RemainingSize, LocMemOffset, true); SDValue Dst = DAG.getFrameIndex(LastFI, PtrType); ByValChain = DAG.getMemcpy(ByValChain, dl, Dst, Src, DAG.getConstant(RemainingSize, MVT::i32), std::min(ByValAlign, (unsigned)4), /*isVolatile=*/false, /*AlwaysInline=*/false, MachinePointerInfo(0), MachinePointerInfo(0)); } // Copy Mips64 byVal arg to registers and stack. void static PassByValArg64(SDValue& ByValChain, SDValue Chain, DebugLoc dl, SmallVector, 16>& RegsToPass, SmallVector& MemOpChains, int& LastFI, MachineFrameInfo *MFI, SelectionDAG &DAG, SDValue Arg, const CCValAssign &VA, const ISD::ArgFlagsTy& Flags, EVT PtrTy, bool isLittle) { unsigned ByValSize = Flags.getByValSize(); unsigned Alignment = std::min(Flags.getByValAlign(), (unsigned)8); bool IsRegLoc = VA.isRegLoc(); unsigned Offset = 0; // Offset in # of bytes from the beginning of struct. unsigned LocMemOffset = 0; if (!IsRegLoc) LocMemOffset = VA.getLocMemOffset(); else { const unsigned *Reg = std::find(Mips64IntRegs, Mips64IntRegs + 8, VA.getLocReg()); const unsigned *RegEnd = Mips64IntRegs + 8; // Copy double words to registers. for (; (Reg != RegEnd) && (ByValSize >= Offset + 8); ++Reg, Offset += 8) { SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, PtrTy, Arg, DAG.getConstant(Offset, PtrTy)); SDValue LoadVal = DAG.getLoad(MVT::i64, dl, Chain, LoadPtr, MachinePointerInfo(), false, false, false, Alignment); MemOpChains.push_back(LoadVal.getValue(1)); RegsToPass.push_back(std::make_pair(*Reg, LoadVal)); } // If there is an argument register available, copy the remainder of the // byval argument with sub-doubleword loads and shifts. if ((Reg != RegEnd) && (ByValSize != Offset)) { assert((ByValSize < Offset + 8) && "Size of the remainder should be smaller than 8-byte."); SDValue Val; for (unsigned LoadSize = 4; Offset < ByValSize; LoadSize /= 2) { unsigned RemSize = ByValSize - Offset; if (RemSize < LoadSize) continue; SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, PtrTy, Arg, DAG.getConstant(Offset, PtrTy)); SDValue LoadVal = DAG.getExtLoad(ISD::ZEXTLOAD, dl, MVT::i64, Chain, LoadPtr, MachinePointerInfo(), MVT::getIntegerVT(LoadSize * 8), false, false, Alignment); MemOpChains.push_back(LoadVal.getValue(1)); // Offset in number of bits from double word boundary. unsigned OffsetDW = (Offset % 8) * 8; unsigned Shamt = isLittle ? OffsetDW : 64 - (OffsetDW + LoadSize * 8); SDValue Shift = DAG.getNode(ISD::SHL, dl, MVT::i64, LoadVal, DAG.getConstant(Shamt, MVT::i32)); Val = Val.getNode() ? DAG.getNode(ISD::OR, dl, MVT::i64, Val, Shift) : Shift; Offset += LoadSize; Alignment = std::min(Alignment, LoadSize); } RegsToPass.push_back(std::make_pair(*Reg, Val)); return; } } unsigned MemCpySize = ByValSize - Offset; if (MemCpySize) { // Create a fixed object on stack at offset LocMemOffset and copy // remainder of byval arg to it with memcpy. SDValue Src = DAG.getNode(ISD::ADD, dl, PtrTy, Arg, DAG.getConstant(Offset, PtrTy)); LastFI = MFI->CreateFixedObject(MemCpySize, LocMemOffset, true); SDValue Dst = DAG.getFrameIndex(LastFI, PtrTy); ByValChain = DAG.getMemcpy(ByValChain, dl, Dst, Src, DAG.getConstant(MemCpySize, PtrTy), Alignment, /*isVolatile=*/false, /*AlwaysInline=*/false, MachinePointerInfo(0), MachinePointerInfo(0)); } } /// LowerCall - functions arguments are copied from virtual regs to /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted. /// TODO: isTailCall. SDValue MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, bool &isTailCall, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // MIPs target does not yet support tail call optimization. isTailCall = false; MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); const TargetFrameLowering *TFL = MF.getTarget().getFrameLowering(); bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_; MipsFunctionInfo *MipsFI = MF.getInfo(); // Analyze operands of the call, assigning locations to each operand. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), getTargetMachine(), ArgLocs, *DAG.getContext()); if (IsO32) CCInfo.AnalyzeCallOperands(Outs, CC_MipsO32); else if (HasMips64) AnalyzeMips64CallOperands(CCInfo, Outs); else CCInfo.AnalyzeCallOperands(Outs, CC_Mips); // Get a count of how many bytes are to be pushed on the stack. unsigned NextStackOffset = CCInfo.getNextStackOffset(); // Chain is the output chain of the last Load/Store or CopyToReg node. // ByValChain is the output chain of the last Memcpy node created for copying // byval arguments to the stack. SDValue Chain, CallSeqStart, ByValChain; SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, true); Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal); ByValChain = InChain; // If this is the first call, create a stack frame object that points to // a location to which .cprestore saves $gp. if (IsO32 && IsPIC && !MipsFI->getGPFI()) MipsFI->setGPFI(MFI->CreateFixedObject(4, 0, true)); // Get the frame index of the stack frame object that points to the location // of dynamically allocated area on the stack. int DynAllocFI = MipsFI->getDynAllocFI(); // Update size of the maximum argument space. // For O32, a minimum of four words (16 bytes) of argument space is // allocated. if (IsO32) NextStackOffset = std::max(NextStackOffset, (unsigned)16); unsigned MaxCallFrameSize = MipsFI->getMaxCallFrameSize(); if (MaxCallFrameSize < NextStackOffset) { MipsFI->setMaxCallFrameSize(NextStackOffset); // Set the offsets relative to $sp of the $gp restore slot and dynamically // allocated stack space. These offsets must be aligned to a boundary // determined by the stack alignment of the ABI. unsigned StackAlignment = TFL->getStackAlignment(); NextStackOffset = (NextStackOffset + StackAlignment - 1) / StackAlignment * StackAlignment; if (MipsFI->needGPSaveRestore()) MFI->setObjectOffset(MipsFI->getGPFI(), NextStackOffset); MFI->setObjectOffset(DynAllocFI, NextStackOffset); } // With EABI is it possible to have 16 args on registers. SmallVector, 16> RegsToPass; SmallVector MemOpChains; int FirstFI = -MFI->getNumFixedObjects() - 1, LastFI = 0; // Walk the register/memloc assignments, inserting copies/loads. for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { SDValue Arg = OutVals[i]; CCValAssign &VA = ArgLocs[i]; MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT(); ISD::ArgFlagsTy Flags = Outs[i].Flags; // ByVal Arg. if (Flags.isByVal()) { assert(Flags.getByValSize() && "ByVal args of size 0 should have been ignored by front-end."); if (IsO32) WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, MFI, DAG, Arg, VA, Flags, getPointerTy(), Subtarget->isLittle()); else PassByValArg64(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, MFI, DAG, Arg, VA, Flags, getPointerTy(), Subtarget->isLittle()); continue; } // Promote the value if needed. switch (VA.getLocInfo()) { default: llvm_unreachable("Unknown loc info!"); case CCValAssign::Full: if (VA.isRegLoc()) { if ((ValVT == MVT::f32 && LocVT == MVT::i32) || (ValVT == MVT::f64 && LocVT == MVT::i64)) Arg = DAG.getNode(ISD::BITCAST, dl, LocVT, Arg); else if (ValVT == MVT::f64 && LocVT == MVT::i32) { SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32, Arg, DAG.getConstant(0, MVT::i32)); SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32, Arg, DAG.getConstant(1, MVT::i32)); if (!Subtarget->isLittle()) std::swap(Lo, Hi); unsigned LocRegLo = VA.getLocReg(); unsigned LocRegHigh = getNextIntArgReg(LocRegLo); RegsToPass.push_back(std::make_pair(LocRegLo, Lo)); RegsToPass.push_back(std::make_pair(LocRegHigh, Hi)); continue; } } break; case CCValAssign::SExt: Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, LocVT, Arg); break; case CCValAssign::ZExt: Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, LocVT, Arg); break; case CCValAssign::AExt: Arg = DAG.getNode(ISD::ANY_EXTEND, dl, LocVT, Arg); break; } // Arguments that can be passed on register must be kept at // RegsToPass vector if (VA.isRegLoc()) { RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg)); continue; } // Register can't get to this point... assert(VA.isMemLoc()); // Create the frame index object for this incoming parameter LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8, VA.getLocMemOffset(), true); SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy()); // emit ISD::STORE whichs stores the // parameter value to a stack Location MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo(), false, false, 0)); } // Extend range of indices of frame objects for outgoing arguments that were // created during this function call. Skip this step if no such objects were // created. if (LastFI) MipsFI->extendOutArgFIRange(FirstFI, LastFI); // If a memcpy has been created to copy a byval arg to a stack, replace the // chain input of CallSeqStart with ByValChain. if (InChain != ByValChain) DAG.UpdateNodeOperands(CallSeqStart.getNode(), ByValChain, NextStackOffsetVal); // Transform all store nodes into one single node because all store // nodes are independent of each other. if (!MemOpChains.empty()) Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &MemOpChains[0], MemOpChains.size()); // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol // node so that legalize doesn't hack it. unsigned char OpFlag; bool IsPICCall = (IsN64 || IsPIC); // true if calls are translated to jalr $25 bool LoadSymAddr = false; SDValue CalleeLo; if (GlobalAddressSDNode *G = dyn_cast(Callee)) { if (IsPICCall && G->getGlobal()->hasInternalLinkage()) { OpFlag = IsO32 ? MipsII::MO_GOT : MipsII::MO_GOT_PAGE; unsigned char LoFlag = IsO32 ? MipsII::MO_ABS_LO : MipsII::MO_GOT_OFST; Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, OpFlag); CalleeLo = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, LoFlag); } else { OpFlag = IsPICCall ? MipsII::MO_GOT_CALL : MipsII::MO_NO_FLAG; Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, OpFlag); } LoadSymAddr = true; } else if (ExternalSymbolSDNode *S = dyn_cast(Callee)) { if (IsN64 || (!IsO32 && IsPIC)) OpFlag = MipsII::MO_GOT_DISP; else if (!IsPIC) // !N64 && static OpFlag = MipsII::MO_NO_FLAG; else // O32 & PIC OpFlag = MipsII::MO_GOT_CALL; Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(), OpFlag); LoadSymAddr = true; } SDValue InFlag; // Create nodes that load address of callee and copy it to T9 if (IsPICCall) { if (LoadSymAddr) { // Load callee address Callee = DAG.getNode(MipsISD::WrapperPIC, dl, getPointerTy(), Callee); SDValue LoadValue = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), Callee, MachinePointerInfo::getGOT(), false, false, false, 0); // Use GOT+LO if callee has internal linkage. if (CalleeLo.getNode()) { SDValue Lo = DAG.getNode(MipsISD::Lo, dl, getPointerTy(), CalleeLo); Callee = DAG.getNode(ISD::ADD, dl, getPointerTy(), LoadValue, Lo); } else Callee = LoadValue; } // copy to T9 unsigned T9Reg = IsN64 ? Mips::T9_64 : Mips::T9; Chain = DAG.getCopyToReg(Chain, dl, T9Reg, Callee, SDValue(0, 0)); InFlag = Chain.getValue(1); Callee = DAG.getRegister(T9Reg, getPointerTy()); } // Build a sequence of copy-to-reg nodes chained together with token // chain and flag operands which copy the outgoing args into registers. // The InFlag in necessary since all emitted instructions must be // stuck together. for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, RegsToPass[i].second, InFlag); InFlag = Chain.getValue(1); } // MipsJmpLink = #chain, #target_address, #opt_in_flags... // = Chain, Callee, Reg#1, Reg#2, ... // // Returns a chain & a flag for retval copy to use. SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); SmallVector Ops; Ops.push_back(Chain); Ops.push_back(Callee); // Add argument registers to the end of the list so that they are // known live into the call. for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) Ops.push_back(DAG.getRegister(RegsToPass[i].first, RegsToPass[i].second.getValueType())); if (InFlag.getNode()) Ops.push_back(InFlag); Chain = DAG.getNode(MipsISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size()); InFlag = Chain.getValue(1); // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NextStackOffset, true), DAG.getIntPtrConstant(0, true), InFlag); InFlag = Chain.getValue(1); // Handle result values, copying them out of physregs into vregs that we // return. return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins, dl, DAG, InVals); } /// LowerCallResult - Lower the result values of a call into the /// appropriate copies out of appropriate physical registers. SDValue MipsTargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // Assign locations to each value returned by this call. SmallVector RVLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), getTargetMachine(), RVLocs, *DAG.getContext()); CCInfo.AnalyzeCallResult(Ins, RetCC_Mips); // Copy all of the result registers out of their specified physreg. for (unsigned i = 0; i != RVLocs.size(); ++i) { Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(), RVLocs[i].getValVT(), InFlag).getValue(1); InFlag = Chain.getValue(2); InVals.push_back(Chain.getValue(0)); } return Chain; } //===----------------------------------------------------------------------===// // Formal Arguments Calling Convention Implementation //===----------------------------------------------------------------------===// static void ReadByValArg(MachineFunction &MF, SDValue Chain, DebugLoc dl, std::vector& OutChains, SelectionDAG &DAG, unsigned NumWords, SDValue FIN, const CCValAssign &VA, const ISD::ArgFlagsTy& Flags) { unsigned LocMem = VA.getLocMemOffset(); unsigned FirstWord = LocMem / 4; // copy register A0 - A3 to frame object for (unsigned i = 0; i < NumWords; ++i) { unsigned CurWord = FirstWord + i; if (CurWord >= O32IntRegsSize) break; unsigned SrcReg = O32IntRegs[CurWord]; unsigned Reg = AddLiveIn(MF, SrcReg, Mips::CPURegsRegisterClass); SDValue StorePtr = DAG.getNode(ISD::ADD, dl, MVT::i32, FIN, DAG.getConstant(i * 4, MVT::i32)); SDValue Store = DAG.getStore(Chain, dl, DAG.getRegister(Reg, MVT::i32), StorePtr, MachinePointerInfo(), false, false, 0); OutChains.push_back(Store); } } // Create frame object on stack and copy registers used for byval passing to it. static unsigned CopyMips64ByValRegs(MachineFunction &MF, SDValue Chain, DebugLoc dl, std::vector& OutChains, SelectionDAG &DAG, const CCValAssign &VA, const ISD::ArgFlagsTy& Flags, MachineFrameInfo *MFI, bool IsRegLoc, SmallVectorImpl &InVals, MipsFunctionInfo *MipsFI, EVT PtrTy) { const unsigned *Reg = Mips64IntRegs + 8; int FOOffset; // Frame object offset from virtual frame pointer. if (IsRegLoc) { Reg = std::find(Mips64IntRegs, Mips64IntRegs + 8, VA.getLocReg()); FOOffset = (Reg - Mips64IntRegs) * 8 - 8 * 8; } else FOOffset = VA.getLocMemOffset(); // Create frame object. unsigned NumRegs = (Flags.getByValSize() + 7) / 8; unsigned LastFI = MFI->CreateFixedObject(NumRegs * 8, FOOffset, true); SDValue FIN = DAG.getFrameIndex(LastFI, PtrTy); InVals.push_back(FIN); // Copy arg registers. for (unsigned I = 0; (Reg != Mips64IntRegs + 8) && (I < NumRegs); ++Reg, ++I) { unsigned VReg = AddLiveIn(MF, *Reg, Mips::CPU64RegsRegisterClass); SDValue StorePtr = DAG.getNode(ISD::ADD, dl, PtrTy, FIN, DAG.getConstant(I * 8, PtrTy)); SDValue Store = DAG.getStore(Chain, dl, DAG.getRegister(VReg, MVT::i64), StorePtr, MachinePointerInfo(), false, false, 0); OutChains.push_back(Store); } return LastFI; } /// LowerFormalArguments - transform physical registers into virtual registers /// and generate load operations for arguments places on the stack. SDValue MipsTargetLowering::LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); MipsFunctionInfo *MipsFI = MF.getInfo(); MipsFI->setVarArgsFrameIndex(0); // Used with vargs to acumulate store chains. std::vector OutChains; // Assign locations to all of the incoming arguments. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), getTargetMachine(), ArgLocs, *DAG.getContext()); if (IsO32) CCInfo.AnalyzeFormalArguments(Ins, CC_MipsO32); else CCInfo.AnalyzeFormalArguments(Ins, CC_Mips); int LastFI = 0;// MipsFI->LastInArgFI is 0 at the entry of this function. for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign &VA = ArgLocs[i]; EVT ValVT = VA.getValVT(); ISD::ArgFlagsTy Flags = Ins[i].Flags; bool IsRegLoc = VA.isRegLoc(); if (Flags.isByVal()) { assert(Flags.getByValSize() && "ByVal args of size 0 should have been ignored by front-end."); if (IsO32) { unsigned NumWords = (Flags.getByValSize() + 3) / 4; LastFI = MFI->CreateFixedObject(NumWords * 4, VA.getLocMemOffset(), true); SDValue FIN = DAG.getFrameIndex(LastFI, getPointerTy()); InVals.push_back(FIN); ReadByValArg(MF, Chain, dl, OutChains, DAG, NumWords, FIN, VA, Flags); } else // N32/64 LastFI = CopyMips64ByValRegs(MF, Chain, dl, OutChains, DAG, VA, Flags, MFI, IsRegLoc, InVals, MipsFI, getPointerTy()); continue; } // Arguments stored on registers if (IsRegLoc) { EVT RegVT = VA.getLocVT(); unsigned ArgReg = VA.getLocReg(); TargetRegisterClass *RC = 0; if (RegVT == MVT::i32) RC = Mips::CPURegsRegisterClass; else if (RegVT == MVT::i64) RC = Mips::CPU64RegsRegisterClass; else if (RegVT == MVT::f32) RC = Mips::FGR32RegisterClass; else if (RegVT == MVT::f64) RC = HasMips64 ? Mips::FGR64RegisterClass : Mips::AFGR64RegisterClass; else llvm_unreachable("RegVT not supported by FormalArguments Lowering"); // Transform the arguments stored on // physical registers into virtual ones unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgReg, RC); SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT); // If this is an 8 or 16-bit value, it has been passed promoted // to 32 bits. Insert an assert[sz]ext to capture this, then // truncate to the right size. if (VA.getLocInfo() != CCValAssign::Full) { unsigned Opcode = 0; if (VA.getLocInfo() == CCValAssign::SExt) Opcode = ISD::AssertSext; else if (VA.getLocInfo() == CCValAssign::ZExt) Opcode = ISD::AssertZext; if (Opcode) ArgValue = DAG.getNode(Opcode, dl, RegVT, ArgValue, DAG.getValueType(ValVT)); ArgValue = DAG.getNode(ISD::TRUNCATE, dl, ValVT, ArgValue); } // Handle floating point arguments passed in integer registers. if ((RegVT == MVT::i32 && ValVT == MVT::f32) || (RegVT == MVT::i64 && ValVT == MVT::f64)) ArgValue = DAG.getNode(ISD::BITCAST, dl, ValVT, ArgValue); else if (IsO32 && RegVT == MVT::i32 && ValVT == MVT::f64) { unsigned Reg2 = AddLiveIn(DAG.getMachineFunction(), getNextIntArgReg(ArgReg), RC); SDValue ArgValue2 = DAG.getCopyFromReg(Chain, dl, Reg2, RegVT); if (!Subtarget->isLittle()) std::swap(ArgValue, ArgValue2); ArgValue = DAG.getNode(MipsISD::BuildPairF64, dl, MVT::f64, ArgValue, ArgValue2); } InVals.push_back(ArgValue); } else { // VA.isRegLoc() // sanity check assert(VA.isMemLoc()); // The stack pointer offset is relative to the caller stack frame. LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8, VA.getLocMemOffset(), true); // Create load nodes to retrieve arguments from the stack SDValue FIN = DAG.getFrameIndex(LastFI, getPointerTy()); InVals.push_back(DAG.getLoad(ValVT, dl, Chain, FIN, MachinePointerInfo::getFixedStack(LastFI), false, false, false, 0)); } } // The mips ABIs for returning structs by value requires that we copy // the sret argument into $v0 for the return. Save the argument into // a virtual register so that we can access it from the return points. if (DAG.getMachineFunction().getFunction()->hasStructRetAttr()) { unsigned Reg = MipsFI->getSRetReturnReg(); if (!Reg) { Reg = MF.getRegInfo().createVirtualRegister(getRegClassFor(MVT::i32)); MipsFI->setSRetReturnReg(Reg); } SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[0]); Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain); } if (isVarArg) { unsigned NumOfRegs = IsO32 ? 4 : 8; const unsigned *ArgRegs = IsO32 ? O32IntRegs : Mips64IntRegs; unsigned Idx = CCInfo.getFirstUnallocated(ArgRegs, NumOfRegs); int FirstRegSlotOffset = IsO32 ? 0 : -64 ; // offset of $a0's slot. TargetRegisterClass *RC = IsO32 ? Mips::CPURegsRegisterClass : Mips::CPU64RegsRegisterClass; unsigned RegSize = RC->getSize(); int RegSlotOffset = FirstRegSlotOffset + Idx * RegSize; // Offset of the first variable argument from stack pointer. int FirstVaArgOffset; if (IsO32 || (Idx == NumOfRegs)) { FirstVaArgOffset = (CCInfo.getNextStackOffset() + RegSize - 1) / RegSize * RegSize; } else FirstVaArgOffset = RegSlotOffset; // Record the frame index of the first variable argument // which is a value necessary to VASTART. LastFI = MFI->CreateFixedObject(RegSize, FirstVaArgOffset, true); MipsFI->setVarArgsFrameIndex(LastFI); // Copy the integer registers that have not been used for argument passing // to the argument register save area. For O32, the save area is allocated // in the caller's stack frame, while for N32/64, it is allocated in the // callee's stack frame. for (int StackOffset = RegSlotOffset; Idx < NumOfRegs; ++Idx, StackOffset += RegSize) { unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegs[Idx], RC); SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, MVT::getIntegerVT(RegSize * 8)); LastFI = MFI->CreateFixedObject(RegSize, StackOffset, true); SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy()); OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff, MachinePointerInfo(), false, false, 0)); } } MipsFI->setLastInArgFI(LastFI); // All stores are grouped in one node to allow the matching between // the size of Ins and InVals. This only happens when on varg functions if (!OutChains.empty()) { OutChains.push_back(Chain); Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &OutChains[0], OutChains.size()); } return Chain; } //===----------------------------------------------------------------------===// // Return Value Calling Convention Implementation //===----------------------------------------------------------------------===// SDValue MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, DebugLoc dl, SelectionDAG &DAG) const { // CCValAssign - represent the assignment of // the return value to a location SmallVector RVLocs; // CCState - Info about the registers and stack slot. CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), getTargetMachine(), RVLocs, *DAG.getContext()); // Analize return values. CCInfo.AnalyzeReturn(Outs, RetCC_Mips); // If this is the first return lowered for this function, add // the regs to the liveout set for the function. if (DAG.getMachineFunction().getRegInfo().liveout_empty()) { for (unsigned i = 0; i != RVLocs.size(); ++i) if (RVLocs[i].isRegLoc()) DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg()); } SDValue Flag; // Copy the result values into the output registers. for (unsigned i = 0; i != RVLocs.size(); ++i) { CCValAssign &VA = RVLocs[i]; assert(VA.isRegLoc() && "Can only return in registers!"); Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), OutVals[i], Flag); // guarantee that all emitted copies are // stuck together, avoiding something bad Flag = Chain.getValue(1); } // The mips ABIs for returning structs by value requires that we copy // the sret argument into $v0 for the return. We saved the argument into // a virtual register in the entry block, so now we copy the value out // and into $v0. if (DAG.getMachineFunction().getFunction()->hasStructRetAttr()) { MachineFunction &MF = DAG.getMachineFunction(); MipsFunctionInfo *MipsFI = MF.getInfo(); unsigned Reg = MipsFI->getSRetReturnReg(); if (!Reg) llvm_unreachable("sret virtual register not created in the entry block"); SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy()); Chain = DAG.getCopyToReg(Chain, dl, Mips::V0, Val, Flag); Flag = Chain.getValue(1); } // Return on Mips is always a "jr $ra" if (Flag.getNode()) return DAG.getNode(MipsISD::Ret, dl, MVT::Other, Chain, DAG.getRegister(Mips::RA, MVT::i32), Flag); else // Return Void return DAG.getNode(MipsISD::Ret, dl, MVT::Other, Chain, DAG.getRegister(Mips::RA, MVT::i32)); } //===----------------------------------------------------------------------===// // Mips Inline Assembly Support //===----------------------------------------------------------------------===// /// getConstraintType - Given a constraint letter, return the type of /// constraint it is for this target. MipsTargetLowering::ConstraintType MipsTargetLowering:: getConstraintType(const std::string &Constraint) const { // Mips specific constrainy // GCC config/mips/constraints.md // // 'd' : An address register. Equivalent to r // unless generating MIPS16 code. // 'y' : Equivalent to r; retained for // backwards compatibility. // 'f' : Floating Point registers. if (Constraint.size() == 1) { switch (Constraint[0]) { default : break; case 'd': case 'y': case 'f': return C_RegisterClass; break; } } return TargetLowering::getConstraintType(Constraint); } /// Examine constraint type and operand type and determine a weight value. /// This object must already have been set up with the operand type /// and the current alternative constraint selected. TargetLowering::ConstraintWeight MipsTargetLowering::getSingleConstraintMatchWeight( AsmOperandInfo &info, const char *constraint) const { ConstraintWeight weight = CW_Invalid; Value *CallOperandVal = info.CallOperandVal; // If we don't have a value, we can't do a match, // but allow it at the lowest weight. if (CallOperandVal == NULL) return CW_Default; Type *type = CallOperandVal->getType(); // Look at the constraint type. switch (*constraint) { default: weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint); break; case 'd': case 'y': if (type->isIntegerTy()) weight = CW_Register; break; case 'f': if (type->isFloatTy()) weight = CW_Register; break; } return weight; } /// Given a register class constraint, like 'r', if this corresponds directly /// to an LLVM register class, return a register of 0 and the register class /// pointer. std::pair MipsTargetLowering:: getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const { if (Constraint.size() == 1) { switch (Constraint[0]) { case 'd': // Address register. Same as 'r' unless generating MIPS16 code. case 'y': // Same as 'r'. Exists for compatibility. case 'r': return std::make_pair(0U, Mips::CPURegsRegisterClass); case 'f': if (VT == MVT::f32) return std::make_pair(0U, Mips::FGR32RegisterClass); if (VT == MVT::f64) if ((!Subtarget->isSingleFloat()) && (!Subtarget->isFP64bit())) return std::make_pair(0U, Mips::AFGR64RegisterClass); break; } } return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT); } bool MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const { // The Mips target isn't yet aware of offsets. return false; } bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const { if (VT != MVT::f32 && VT != MVT::f64) return false; if (Imm.isNegZero()) return false; return Imm.isZero(); }