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Diffstat (limited to 'contrib/llvm/lib/Target/Mips/MipsISelDAGToDAG.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/Mips/MipsISelDAGToDAG.cpp | 592 |
1 files changed, 592 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Mips/MipsISelDAGToDAG.cpp b/contrib/llvm/lib/Target/Mips/MipsISelDAGToDAG.cpp new file mode 100644 index 0000000..5a97c17 --- /dev/null +++ b/contrib/llvm/lib/Target/Mips/MipsISelDAGToDAG.cpp @@ -0,0 +1,592 @@ +//===-- MipsISelDAGToDAG.cpp - A Dag to Dag Inst Selector for Mips --------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines an instruction selector for the MIPS target. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "mips-isel" +#include "Mips.h" +#include "MipsAnalyzeImmediate.h" +#include "MipsMachineFunction.h" +#include "MipsRegisterInfo.h" +#include "MipsSubtarget.h" +#include "MipsTargetMachine.h" +#include "MCTargetDesc/MipsBaseInfo.h" +#include "llvm/GlobalValue.h" +#include "llvm/Instructions.h" +#include "llvm/Intrinsics.h" +#include "llvm/Support/CFG.h" +#include "llvm/Type.h" +#include "llvm/CodeGen/MachineConstantPool.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/SelectionDAGISel.h" +#include "llvm/CodeGen/SelectionDAGNodes.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" +using namespace llvm; + +//===----------------------------------------------------------------------===// +// Instruction Selector Implementation +//===----------------------------------------------------------------------===// + +//===----------------------------------------------------------------------===// +// MipsDAGToDAGISel - MIPS specific code to select MIPS machine +// instructions for SelectionDAG operations. +//===----------------------------------------------------------------------===// +namespace { + +class MipsDAGToDAGISel : public SelectionDAGISel { + + /// TM - Keep a reference to MipsTargetMachine. + MipsTargetMachine &TM; + + /// Subtarget - Keep a pointer to the MipsSubtarget around so that we can + /// make the right decision when generating code for different targets. + const MipsSubtarget &Subtarget; + +public: + explicit MipsDAGToDAGISel(MipsTargetMachine &tm) : + SelectionDAGISel(tm), + TM(tm), Subtarget(tm.getSubtarget<MipsSubtarget>()) {} + + // Pass Name + virtual const char *getPassName() const { + return "MIPS DAG->DAG Pattern Instruction Selection"; + } + + virtual bool runOnMachineFunction(MachineFunction &MF); + +private: + // Include the pieces autogenerated from the target description. + #include "MipsGenDAGISel.inc" + + /// getTargetMachine - Return a reference to the TargetMachine, casted + /// to the target-specific type. + const MipsTargetMachine &getTargetMachine() { + return static_cast<const MipsTargetMachine &>(TM); + } + + /// getInstrInfo - Return a reference to the TargetInstrInfo, casted + /// to the target-specific type. + const MipsInstrInfo *getInstrInfo() { + return getTargetMachine().getInstrInfo(); + } + + SDNode *getGlobalBaseReg(); + + std::pair<SDNode*, SDNode*> SelectMULT(SDNode *N, unsigned Opc, DebugLoc dl, + EVT Ty, bool HasLo, bool HasHi); + + SDNode *Select(SDNode *N); + + // Complex Pattern. + bool SelectAddr(SDNode *Parent, SDValue N, SDValue &Base, SDValue &Offset); + + // getImm - Return a target constant with the specified value. + inline SDValue getImm(const SDNode *Node, unsigned Imm) { + return CurDAG->getTargetConstant(Imm, Node->getValueType(0)); + } + + void ProcessFunctionAfterISel(MachineFunction &MF); + bool ReplaceUsesWithZeroReg(MachineRegisterInfo *MRI, const MachineInstr&); + void InitGlobalBaseReg(MachineFunction &MF); + + virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op, + char ConstraintCode, + std::vector<SDValue> &OutOps); +}; + +} + +// Insert instructions to initialize the global base register in the +// first MBB of the function. When the ABI is O32 and the relocation model is +// PIC, the necessary instructions are emitted later to prevent optimization +// passes from moving them. +void MipsDAGToDAGISel::InitGlobalBaseReg(MachineFunction &MF) { + MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>(); + + if (!MipsFI->globalBaseRegSet()) + return; + + MachineBasicBlock &MBB = MF.front(); + MachineBasicBlock::iterator I = MBB.begin(); + MachineRegisterInfo &RegInfo = MF.getRegInfo(); + const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo(); + DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc(); + unsigned V0, V1, V2, GlobalBaseReg = MipsFI->getGlobalBaseReg(); + const TargetRegisterClass *RC; + + if (Subtarget.isABI_N64()) + RC = (const TargetRegisterClass*)&Mips::CPU64RegsRegClass; + else if (Subtarget.inMips16Mode()) + RC = (const TargetRegisterClass*)&Mips::CPU16RegsRegClass; + else + RC = (const TargetRegisterClass*)&Mips::CPURegsRegClass; + + V0 = RegInfo.createVirtualRegister(RC); + V1 = RegInfo.createVirtualRegister(RC); + V2 = RegInfo.createVirtualRegister(RC); + + if (Subtarget.isABI_N64()) { + MF.getRegInfo().addLiveIn(Mips::T9_64); + MBB.addLiveIn(Mips::T9_64); + + // lui $v0, %hi(%neg(%gp_rel(fname))) + // daddu $v1, $v0, $t9 + // daddiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname))) + const GlobalValue *FName = MF.getFunction(); + BuildMI(MBB, I, DL, TII.get(Mips::LUi64), V0) + .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI); + BuildMI(MBB, I, DL, TII.get(Mips::DADDu), V1).addReg(V0) + .addReg(Mips::T9_64); + BuildMI(MBB, I, DL, TII.get(Mips::DADDiu), GlobalBaseReg).addReg(V1) + .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO); + return; + } + + if (Subtarget.inMips16Mode()) { + BuildMI(MBB, I, DL, TII.get(Mips::LiRxImmX16), V0) + .addExternalSymbol("_gp_disp", MipsII::MO_ABS_HI); + BuildMI(MBB, I, DL, TII.get(Mips::AddiuRxPcImmX16), V1) + .addExternalSymbol("_gp_disp", MipsII::MO_ABS_LO); + BuildMI(MBB, I, DL, TII.get(Mips::SllX16), V2).addReg(V0).addImm(16); + BuildMI(MBB, I, DL, TII.get(Mips::AdduRxRyRz16), GlobalBaseReg) + .addReg(V1).addReg(V2); + return; + } + + if (MF.getTarget().getRelocationModel() == Reloc::Static) { + // Set global register to __gnu_local_gp. + // + // lui $v0, %hi(__gnu_local_gp) + // addiu $globalbasereg, $v0, %lo(__gnu_local_gp) + BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0) + .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_HI); + BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V0) + .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_LO); + return; + } + + MF.getRegInfo().addLiveIn(Mips::T9); + MBB.addLiveIn(Mips::T9); + + if (Subtarget.isABI_N32()) { + // lui $v0, %hi(%neg(%gp_rel(fname))) + // addu $v1, $v0, $t9 + // addiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname))) + const GlobalValue *FName = MF.getFunction(); + BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0) + .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI); + BuildMI(MBB, I, DL, TII.get(Mips::ADDu), V1).addReg(V0).addReg(Mips::T9); + BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V1) + .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO); + return; + } + + assert(Subtarget.isABI_O32()); + + // For O32 ABI, the following instruction sequence is emitted to initialize + // the global base register: + // + // 0. lui $2, %hi(_gp_disp) + // 1. addiu $2, $2, %lo(_gp_disp) + // 2. addu $globalbasereg, $2, $t9 + // + // We emit only the last instruction here. + // + // GNU linker requires that the first two instructions appear at the beginning + // of a function and no instructions be inserted before or between them. + // The two instructions are emitted during lowering to MC layer in order to + // avoid any reordering. + // + // Register $2 (Mips::V0) is added to the list of live-in registers to ensure + // the value instruction 1 (addiu) defines is valid when instruction 2 (addu) + // reads it. + MF.getRegInfo().addLiveIn(Mips::V0); + MBB.addLiveIn(Mips::V0); + BuildMI(MBB, I, DL, TII.get(Mips::ADDu), GlobalBaseReg) + .addReg(Mips::V0).addReg(Mips::T9); +} + +bool MipsDAGToDAGISel::ReplaceUsesWithZeroReg(MachineRegisterInfo *MRI, + const MachineInstr& MI) { + unsigned DstReg = 0, ZeroReg = 0; + + // Check if MI is "addiu $dst, $zero, 0" or "daddiu $dst, $zero, 0". + if ((MI.getOpcode() == Mips::ADDiu) && + (MI.getOperand(1).getReg() == Mips::ZERO) && + (MI.getOperand(2).getImm() == 0)) { + DstReg = MI.getOperand(0).getReg(); + ZeroReg = Mips::ZERO; + } else if ((MI.getOpcode() == Mips::DADDiu) && + (MI.getOperand(1).getReg() == Mips::ZERO_64) && + (MI.getOperand(2).getImm() == 0)) { + DstReg = MI.getOperand(0).getReg(); + ZeroReg = Mips::ZERO_64; + } + + if (!DstReg) + return false; + + // Replace uses with ZeroReg. + for (MachineRegisterInfo::use_iterator U = MRI->use_begin(DstReg), + E = MRI->use_end(); U != E;) { + MachineOperand &MO = U.getOperand(); + unsigned OpNo = U.getOperandNo(); + MachineInstr *MI = MO.getParent(); + ++U; + + // Do not replace if it is a phi's operand or is tied to def operand. + if (MI->isPHI() || MI->isRegTiedToDefOperand(OpNo) || MI->isPseudo()) + continue; + + MO.setReg(ZeroReg); + } + + return true; +} + +void MipsDAGToDAGISel::ProcessFunctionAfterISel(MachineFunction &MF) { + InitGlobalBaseReg(MF); + + MachineRegisterInfo *MRI = &MF.getRegInfo(); + + for (MachineFunction::iterator MFI = MF.begin(), MFE = MF.end(); MFI != MFE; + ++MFI) + for (MachineBasicBlock::iterator I = MFI->begin(); I != MFI->end(); ++I) + ReplaceUsesWithZeroReg(MRI, *I); +} + +bool MipsDAGToDAGISel::runOnMachineFunction(MachineFunction &MF) { + bool Ret = SelectionDAGISel::runOnMachineFunction(MF); + + ProcessFunctionAfterISel(MF); + + return Ret; +} + +/// getGlobalBaseReg - Output the instructions required to put the +/// GOT address into a register. +SDNode *MipsDAGToDAGISel::getGlobalBaseReg() { + unsigned GlobalBaseReg = MF->getInfo<MipsFunctionInfo>()->getGlobalBaseReg(); + return CurDAG->getRegister(GlobalBaseReg, TLI.getPointerTy()).getNode(); +} + +/// ComplexPattern used on MipsInstrInfo +/// Used on Mips Load/Store instructions +bool MipsDAGToDAGISel:: +SelectAddr(SDNode *Parent, SDValue Addr, SDValue &Base, SDValue &Offset) { + EVT ValTy = Addr.getValueType(); + + // if Address is FI, get the TargetFrameIndex. + if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) { + Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy); + Offset = CurDAG->getTargetConstant(0, ValTy); + return true; + } + + // on PIC code Load GA + if (Addr.getOpcode() == MipsISD::Wrapper) { + Base = Addr.getOperand(0); + Offset = Addr.getOperand(1); + return true; + } + + if (TM.getRelocationModel() != Reloc::PIC_) { + if ((Addr.getOpcode() == ISD::TargetExternalSymbol || + Addr.getOpcode() == ISD::TargetGlobalAddress)) + return false; + } + + // Addresses of the form FI+const or FI|const + if (CurDAG->isBaseWithConstantOffset(Addr)) { + ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)); + if (isInt<16>(CN->getSExtValue())) { + + // If the first operand is a FI, get the TargetFI Node + if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode> + (Addr.getOperand(0))) + Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy); + else + Base = Addr.getOperand(0); + + Offset = CurDAG->getTargetConstant(CN->getZExtValue(), ValTy); + return true; + } + } + + // Operand is a result from an ADD. + if (Addr.getOpcode() == ISD::ADD) { + // When loading from constant pools, load the lower address part in + // the instruction itself. Example, instead of: + // lui $2, %hi($CPI1_0) + // addiu $2, $2, %lo($CPI1_0) + // lwc1 $f0, 0($2) + // Generate: + // lui $2, %hi($CPI1_0) + // lwc1 $f0, %lo($CPI1_0)($2) + if (Addr.getOperand(1).getOpcode() == MipsISD::Lo) { + SDValue LoVal = Addr.getOperand(1), Opnd0 = LoVal.getOperand(0); + if (isa<ConstantPoolSDNode>(Opnd0) || isa<GlobalAddressSDNode>(Opnd0) || + isa<JumpTableSDNode>(Opnd0)) { + Base = Addr.getOperand(0); + Offset = Opnd0; + return true; + } + } + + // If an indexed floating point load/store can be emitted, return false. + const LSBaseSDNode *LS = dyn_cast<LSBaseSDNode>(Parent); + + if (LS && + (LS->getMemoryVT() == MVT::f32 || LS->getMemoryVT() == MVT::f64) && + Subtarget.hasMips32r2Or64()) + return false; + } + + Base = Addr; + Offset = CurDAG->getTargetConstant(0, ValTy); + return true; +} + +/// Select multiply instructions. +std::pair<SDNode*, SDNode*> +MipsDAGToDAGISel::SelectMULT(SDNode *N, unsigned Opc, DebugLoc dl, EVT Ty, + bool HasLo, bool HasHi) { + SDNode *Lo = 0, *Hi = 0; + SDNode *Mul = CurDAG->getMachineNode(Opc, dl, MVT::Glue, N->getOperand(0), + N->getOperand(1)); + SDValue InFlag = SDValue(Mul, 0); + + if (HasLo) { + Lo = CurDAG->getMachineNode(Ty == MVT::i32 ? Mips::MFLO : Mips::MFLO64, dl, + Ty, MVT::Glue, InFlag); + InFlag = SDValue(Lo, 1); + } + if (HasHi) + Hi = CurDAG->getMachineNode(Ty == MVT::i32 ? Mips::MFHI : Mips::MFHI64, dl, + Ty, InFlag); + + return std::make_pair(Lo, Hi); +} + + +/// Select instructions not customized! Used for +/// expanded, promoted and normal instructions +SDNode* MipsDAGToDAGISel::Select(SDNode *Node) { + unsigned Opcode = Node->getOpcode(); + DebugLoc dl = Node->getDebugLoc(); + + // Dump information about the Node being selected + DEBUG(errs() << "Selecting: "; Node->dump(CurDAG); errs() << "\n"); + + // If we have a custom node, we already have selected! + if (Node->isMachineOpcode()) { + DEBUG(errs() << "== "; Node->dump(CurDAG); errs() << "\n"); + return NULL; + } + + /// + // Instruction Selection not handled by the auto-generated + // tablegen selection should be handled here. + /// + EVT NodeTy = Node->getValueType(0); + unsigned MultOpc; + + switch(Opcode) { + default: break; + + case ISD::SUBE: + case ISD::ADDE: { + SDValue InFlag = Node->getOperand(2), CmpLHS; + unsigned Opc = InFlag.getOpcode(); (void)Opc; + assert(((Opc == ISD::ADDC || Opc == ISD::ADDE) || + (Opc == ISD::SUBC || Opc == ISD::SUBE)) && + "(ADD|SUB)E flag operand must come from (ADD|SUB)C/E insn"); + + unsigned MOp; + if (Opcode == ISD::ADDE) { + CmpLHS = InFlag.getValue(0); + MOp = Mips::ADDu; + } else { + CmpLHS = InFlag.getOperand(0); + MOp = Mips::SUBu; + } + + SDValue Ops[] = { CmpLHS, InFlag.getOperand(1) }; + + SDValue LHS = Node->getOperand(0); + SDValue RHS = Node->getOperand(1); + + EVT VT = LHS.getValueType(); + SDNode *Carry = CurDAG->getMachineNode(Mips::SLTu, dl, VT, Ops, 2); + SDNode *AddCarry = CurDAG->getMachineNode(Mips::ADDu, dl, VT, + SDValue(Carry,0), RHS); + + return CurDAG->SelectNodeTo(Node, MOp, VT, MVT::Glue, + LHS, SDValue(AddCarry,0)); + } + + /// Mul with two results + case ISD::SMUL_LOHI: + case ISD::UMUL_LOHI: { + if (NodeTy == MVT::i32) + MultOpc = (Opcode == ISD::UMUL_LOHI ? Mips::MULTu : Mips::MULT); + else + MultOpc = (Opcode == ISD::UMUL_LOHI ? Mips::DMULTu : Mips::DMULT); + + std::pair<SDNode*, SDNode*> LoHi = SelectMULT(Node, MultOpc, dl, NodeTy, + true, true); + + if (!SDValue(Node, 0).use_empty()) + ReplaceUses(SDValue(Node, 0), SDValue(LoHi.first, 0)); + + if (!SDValue(Node, 1).use_empty()) + ReplaceUses(SDValue(Node, 1), SDValue(LoHi.second, 0)); + + return NULL; + } + + /// Special Muls + case ISD::MUL: { + // Mips32 has a 32-bit three operand mul instruction. + if (Subtarget.hasMips32() && NodeTy == MVT::i32) + break; + return SelectMULT(Node, NodeTy == MVT::i32 ? Mips::MULT : Mips::DMULT, + dl, NodeTy, true, false).first; + } + case ISD::MULHS: + case ISD::MULHU: { + if (NodeTy == MVT::i32) + MultOpc = (Opcode == ISD::MULHU ? Mips::MULTu : Mips::MULT); + else + MultOpc = (Opcode == ISD::MULHU ? Mips::DMULTu : Mips::DMULT); + + return SelectMULT(Node, MultOpc, dl, NodeTy, false, true).second; + } + + // Get target GOT address. + case ISD::GLOBAL_OFFSET_TABLE: + return getGlobalBaseReg(); + + case ISD::ConstantFP: { + ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(Node); + if (Node->getValueType(0) == MVT::f64 && CN->isExactlyValue(+0.0)) { + if (Subtarget.hasMips64()) { + SDValue Zero = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), dl, + Mips::ZERO_64, MVT::i64); + return CurDAG->getMachineNode(Mips::DMTC1, dl, MVT::f64, Zero); + } + + SDValue Zero = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), dl, + Mips::ZERO, MVT::i32); + return CurDAG->getMachineNode(Mips::BuildPairF64, dl, MVT::f64, Zero, + Zero); + } + break; + } + + case ISD::Constant: { + const ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Node); + unsigned Size = CN->getValueSizeInBits(0); + + if (Size == 32) + break; + + MipsAnalyzeImmediate AnalyzeImm; + int64_t Imm = CN->getSExtValue(); + + const MipsAnalyzeImmediate::InstSeq &Seq = + AnalyzeImm.Analyze(Imm, Size, false); + + MipsAnalyzeImmediate::InstSeq::const_iterator Inst = Seq.begin(); + DebugLoc DL = CN->getDebugLoc(); + SDNode *RegOpnd; + SDValue ImmOpnd = CurDAG->getTargetConstant(SignExtend64<16>(Inst->ImmOpnd), + MVT::i64); + + // The first instruction can be a LUi which is different from other + // instructions (ADDiu, ORI and SLL) in that it does not have a register + // operand. + if (Inst->Opc == Mips::LUi64) + RegOpnd = CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, ImmOpnd); + else + RegOpnd = + CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, + CurDAG->getRegister(Mips::ZERO_64, MVT::i64), + ImmOpnd); + + // The remaining instructions in the sequence are handled here. + for (++Inst; Inst != Seq.end(); ++Inst) { + ImmOpnd = CurDAG->getTargetConstant(SignExtend64<16>(Inst->ImmOpnd), + MVT::i64); + RegOpnd = CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, + SDValue(RegOpnd, 0), ImmOpnd); + } + + return RegOpnd; + } + + case MipsISD::ThreadPointer: { + EVT PtrVT = TLI.getPointerTy(); + unsigned RdhwrOpc, SrcReg, DestReg; + + if (PtrVT == MVT::i32) { + RdhwrOpc = Mips::RDHWR; + SrcReg = Mips::HWR29; + DestReg = Mips::V1; + } else { + RdhwrOpc = Mips::RDHWR64; + SrcReg = Mips::HWR29_64; + DestReg = Mips::V1_64; + } + + SDNode *Rdhwr = + CurDAG->getMachineNode(RdhwrOpc, Node->getDebugLoc(), + Node->getValueType(0), + CurDAG->getRegister(SrcReg, PtrVT)); + SDValue Chain = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, DestReg, + SDValue(Rdhwr, 0)); + SDValue ResNode = CurDAG->getCopyFromReg(Chain, dl, DestReg, PtrVT); + ReplaceUses(SDValue(Node, 0), ResNode); + return ResNode.getNode(); + } + } + + // Select the default instruction + SDNode *ResNode = SelectCode(Node); + + DEBUG(errs() << "=> "); + if (ResNode == NULL || ResNode == Node) + DEBUG(Node->dump(CurDAG)); + else + DEBUG(ResNode->dump(CurDAG)); + DEBUG(errs() << "\n"); + return ResNode; +} + +bool MipsDAGToDAGISel:: +SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode, + std::vector<SDValue> &OutOps) { + assert(ConstraintCode == 'm' && "unexpected asm memory constraint"); + OutOps.push_back(Op); + return false; +} + +/// createMipsISelDag - This pass converts a legalized DAG into a +/// MIPS-specific DAG, ready for instruction scheduling. +FunctionPass *llvm::createMipsISelDag(MipsTargetMachine &TM) { + return new MipsDAGToDAGISel(TM); +} |