MipsSEISelDAGToDAG.cpp revision 906ae15d5fa5784595273228b33e16ca16a0431d
1//===-- MipsSEISelDAGToDAG.cpp - A Dag to Dag Inst Selector for MipsSE ----===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Subclass of MipsDAGToDAGISel specialized for mips32/64. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "mips-isel" 15#include "MipsSEISelDAGToDAG.h" 16#include "Mips.h" 17#include "MCTargetDesc/MipsBaseInfo.h" 18#include "MipsAnalyzeImmediate.h" 19#include "MipsMachineFunction.h" 20#include "MipsRegisterInfo.h" 21#include "llvm/CodeGen/MachineConstantPool.h" 22#include "llvm/CodeGen/MachineFrameInfo.h" 23#include "llvm/CodeGen/MachineFunction.h" 24#include "llvm/CodeGen/MachineInstrBuilder.h" 25#include "llvm/CodeGen/MachineRegisterInfo.h" 26#include "llvm/CodeGen/SelectionDAGNodes.h" 27#include "llvm/IR/GlobalValue.h" 28#include "llvm/IR/Instructions.h" 29#include "llvm/IR/Intrinsics.h" 30#include "llvm/IR/Type.h" 31#include "llvm/Support/CFG.h" 32#include "llvm/Support/Debug.h" 33#include "llvm/Support/ErrorHandling.h" 34#include "llvm/Support/raw_ostream.h" 35#include "llvm/Target/TargetMachine.h" 36using namespace llvm; 37 38bool MipsSEDAGToDAGISel::runOnMachineFunction(MachineFunction &MF) { 39 if (Subtarget.inMips16Mode()) 40 return false; 41 return MipsDAGToDAGISel::runOnMachineFunction(MF); 42} 43 44void MipsSEDAGToDAGISel::addDSPCtrlRegOperands(bool IsDef, MachineInstr &MI, 45 MachineFunction &MF) { 46 MachineInstrBuilder MIB(MF, &MI); 47 unsigned Mask = MI.getOperand(1).getImm(); 48 unsigned Flag = IsDef ? RegState::ImplicitDefine : RegState::Implicit; 49 50 if (Mask & 1) 51 MIB.addReg(Mips::DSPPos, Flag); 52 53 if (Mask & 2) 54 MIB.addReg(Mips::DSPSCount, Flag); 55 56 if (Mask & 4) 57 MIB.addReg(Mips::DSPCarry, Flag); 58 59 if (Mask & 8) 60 MIB.addReg(Mips::DSPOutFlag, Flag); 61 62 if (Mask & 16) 63 MIB.addReg(Mips::DSPCCond, Flag); 64 65 if (Mask & 32) 66 MIB.addReg(Mips::DSPEFI, Flag); 67} 68 69unsigned MipsSEDAGToDAGISel::getMSACtrlReg(const SDValue RegIdx) const { 70 switch (cast<ConstantSDNode>(RegIdx)->getZExtValue()) { 71 default: 72 llvm_unreachable("Could not map int to register"); 73 case 0: return Mips::MSAIR; 74 case 1: return Mips::MSACSR; 75 case 2: return Mips::MSAAccess; 76 case 3: return Mips::MSASave; 77 case 4: return Mips::MSAModify; 78 case 5: return Mips::MSARequest; 79 case 6: return Mips::MSAMap; 80 case 7: return Mips::MSAUnmap; 81 } 82} 83 84bool MipsSEDAGToDAGISel::replaceUsesWithZeroReg(MachineRegisterInfo *MRI, 85 const MachineInstr& MI) { 86 unsigned DstReg = 0, ZeroReg = 0; 87 88 // Check if MI is "addiu $dst, $zero, 0" or "daddiu $dst, $zero, 0". 89 if ((MI.getOpcode() == Mips::ADDiu) && 90 (MI.getOperand(1).getReg() == Mips::ZERO) && 91 (MI.getOperand(2).getImm() == 0)) { 92 DstReg = MI.getOperand(0).getReg(); 93 ZeroReg = Mips::ZERO; 94 } else if ((MI.getOpcode() == Mips::DADDiu) && 95 (MI.getOperand(1).getReg() == Mips::ZERO_64) && 96 (MI.getOperand(2).getImm() == 0)) { 97 DstReg = MI.getOperand(0).getReg(); 98 ZeroReg = Mips::ZERO_64; 99 } 100 101 if (!DstReg) 102 return false; 103 104 // Replace uses with ZeroReg. 105 for (MachineRegisterInfo::use_iterator U = MRI->use_begin(DstReg), 106 E = MRI->use_end(); U != E;) { 107 MachineOperand &MO = U.getOperand(); 108 unsigned OpNo = U.getOperandNo(); 109 MachineInstr *MI = MO.getParent(); 110 ++U; 111 112 // Do not replace if it is a phi's operand or is tied to def operand. 113 if (MI->isPHI() || MI->isRegTiedToDefOperand(OpNo) || MI->isPseudo()) 114 continue; 115 116 MO.setReg(ZeroReg); 117 } 118 119 return true; 120} 121 122void MipsSEDAGToDAGISel::initGlobalBaseReg(MachineFunction &MF) { 123 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>(); 124 125 if (!MipsFI->globalBaseRegSet()) 126 return; 127 128 MachineBasicBlock &MBB = MF.front(); 129 MachineBasicBlock::iterator I = MBB.begin(); 130 MachineRegisterInfo &RegInfo = MF.getRegInfo(); 131 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo(); 132 DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc(); 133 unsigned V0, V1, GlobalBaseReg = MipsFI->getGlobalBaseReg(); 134 const TargetRegisterClass *RC; 135 136 if (Subtarget.isABI_N64()) 137 RC = (const TargetRegisterClass*)&Mips::GPR64RegClass; 138 else 139 RC = (const TargetRegisterClass*)&Mips::GPR32RegClass; 140 141 V0 = RegInfo.createVirtualRegister(RC); 142 V1 = RegInfo.createVirtualRegister(RC); 143 144 if (Subtarget.isABI_N64()) { 145 MF.getRegInfo().addLiveIn(Mips::T9_64); 146 MBB.addLiveIn(Mips::T9_64); 147 148 // lui $v0, %hi(%neg(%gp_rel(fname))) 149 // daddu $v1, $v0, $t9 150 // daddiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname))) 151 const GlobalValue *FName = MF.getFunction(); 152 BuildMI(MBB, I, DL, TII.get(Mips::LUi64), V0) 153 .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI); 154 BuildMI(MBB, I, DL, TII.get(Mips::DADDu), V1).addReg(V0) 155 .addReg(Mips::T9_64); 156 BuildMI(MBB, I, DL, TII.get(Mips::DADDiu), GlobalBaseReg).addReg(V1) 157 .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO); 158 return; 159 } 160 161 if (MF.getTarget().getRelocationModel() == Reloc::Static) { 162 // Set global register to __gnu_local_gp. 163 // 164 // lui $v0, %hi(__gnu_local_gp) 165 // addiu $globalbasereg, $v0, %lo(__gnu_local_gp) 166 BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0) 167 .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_HI); 168 BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V0) 169 .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_LO); 170 return; 171 } 172 173 MF.getRegInfo().addLiveIn(Mips::T9); 174 MBB.addLiveIn(Mips::T9); 175 176 if (Subtarget.isABI_N32()) { 177 // lui $v0, %hi(%neg(%gp_rel(fname))) 178 // addu $v1, $v0, $t9 179 // addiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname))) 180 const GlobalValue *FName = MF.getFunction(); 181 BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0) 182 .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI); 183 BuildMI(MBB, I, DL, TII.get(Mips::ADDu), V1).addReg(V0).addReg(Mips::T9); 184 BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V1) 185 .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO); 186 return; 187 } 188 189 assert(Subtarget.isABI_O32()); 190 191 // For O32 ABI, the following instruction sequence is emitted to initialize 192 // the global base register: 193 // 194 // 0. lui $2, %hi(_gp_disp) 195 // 1. addiu $2, $2, %lo(_gp_disp) 196 // 2. addu $globalbasereg, $2, $t9 197 // 198 // We emit only the last instruction here. 199 // 200 // GNU linker requires that the first two instructions appear at the beginning 201 // of a function and no instructions be inserted before or between them. 202 // The two instructions are emitted during lowering to MC layer in order to 203 // avoid any reordering. 204 // 205 // Register $2 (Mips::V0) is added to the list of live-in registers to ensure 206 // the value instruction 1 (addiu) defines is valid when instruction 2 (addu) 207 // reads it. 208 MF.getRegInfo().addLiveIn(Mips::V0); 209 MBB.addLiveIn(Mips::V0); 210 BuildMI(MBB, I, DL, TII.get(Mips::ADDu), GlobalBaseReg) 211 .addReg(Mips::V0).addReg(Mips::T9); 212} 213 214void MipsSEDAGToDAGISel::processFunctionAfterISel(MachineFunction &MF) { 215 initGlobalBaseReg(MF); 216 217 MachineRegisterInfo *MRI = &MF.getRegInfo(); 218 219 for (MachineFunction::iterator MFI = MF.begin(), MFE = MF.end(); MFI != MFE; 220 ++MFI) 221 for (MachineBasicBlock::iterator I = MFI->begin(); I != MFI->end(); ++I) { 222 if (I->getOpcode() == Mips::RDDSP) 223 addDSPCtrlRegOperands(false, *I, MF); 224 else if (I->getOpcode() == Mips::WRDSP) 225 addDSPCtrlRegOperands(true, *I, MF); 226 else 227 replaceUsesWithZeroReg(MRI, *I); 228 } 229} 230 231SDNode *MipsSEDAGToDAGISel::selectAddESubE(unsigned MOp, SDValue InFlag, 232 SDValue CmpLHS, SDLoc DL, 233 SDNode *Node) const { 234 unsigned Opc = InFlag.getOpcode(); (void)Opc; 235 236 assert(((Opc == ISD::ADDC || Opc == ISD::ADDE) || 237 (Opc == ISD::SUBC || Opc == ISD::SUBE)) && 238 "(ADD|SUB)E flag operand must come from (ADD|SUB)C/E insn"); 239 240 SDValue Ops[] = { CmpLHS, InFlag.getOperand(1) }; 241 SDValue LHS = Node->getOperand(0), RHS = Node->getOperand(1); 242 EVT VT = LHS.getValueType(); 243 244 SDNode *Carry = CurDAG->getMachineNode(Mips::SLTu, DL, VT, Ops); 245 SDNode *AddCarry = CurDAG->getMachineNode(Mips::ADDu, DL, VT, 246 SDValue(Carry, 0), RHS); 247 return CurDAG->SelectNodeTo(Node, MOp, VT, MVT::Glue, LHS, 248 SDValue(AddCarry, 0)); 249} 250 251/// ComplexPattern used on MipsInstrInfo 252/// Used on Mips Load/Store instructions 253bool MipsSEDAGToDAGISel::selectAddrRegImm(SDValue Addr, SDValue &Base, 254 SDValue &Offset) const { 255 EVT ValTy = Addr.getValueType(); 256 257 // if Address is FI, get the TargetFrameIndex. 258 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) { 259 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy); 260 Offset = CurDAG->getTargetConstant(0, ValTy); 261 return true; 262 } 263 264 // on PIC code Load GA 265 if (Addr.getOpcode() == MipsISD::Wrapper) { 266 Base = Addr.getOperand(0); 267 Offset = Addr.getOperand(1); 268 return true; 269 } 270 271 if (TM.getRelocationModel() != Reloc::PIC_) { 272 if ((Addr.getOpcode() == ISD::TargetExternalSymbol || 273 Addr.getOpcode() == ISD::TargetGlobalAddress)) 274 return false; 275 } 276 277 // Addresses of the form FI+const or FI|const 278 if (CurDAG->isBaseWithConstantOffset(Addr)) { 279 ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)); 280 if (isInt<16>(CN->getSExtValue())) { 281 282 // If the first operand is a FI, get the TargetFI Node 283 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode> 284 (Addr.getOperand(0))) 285 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy); 286 else 287 Base = Addr.getOperand(0); 288 289 Offset = CurDAG->getTargetConstant(CN->getZExtValue(), ValTy); 290 return true; 291 } 292 } 293 294 // Operand is a result from an ADD. 295 if (Addr.getOpcode() == ISD::ADD) { 296 // When loading from constant pools, load the lower address part in 297 // the instruction itself. Example, instead of: 298 // lui $2, %hi($CPI1_0) 299 // addiu $2, $2, %lo($CPI1_0) 300 // lwc1 $f0, 0($2) 301 // Generate: 302 // lui $2, %hi($CPI1_0) 303 // lwc1 $f0, %lo($CPI1_0)($2) 304 if (Addr.getOperand(1).getOpcode() == MipsISD::Lo || 305 Addr.getOperand(1).getOpcode() == MipsISD::GPRel) { 306 SDValue Opnd0 = Addr.getOperand(1).getOperand(0); 307 if (isa<ConstantPoolSDNode>(Opnd0) || isa<GlobalAddressSDNode>(Opnd0) || 308 isa<JumpTableSDNode>(Opnd0)) { 309 Base = Addr.getOperand(0); 310 Offset = Opnd0; 311 return true; 312 } 313 } 314 } 315 316 return false; 317} 318 319/// ComplexPattern used on MipsInstrInfo 320/// Used on Mips Load/Store instructions 321bool MipsSEDAGToDAGISel::selectAddrRegReg(SDValue Addr, SDValue &Base, 322 SDValue &Offset) const { 323 // Operand is a result from an ADD. 324 if (Addr.getOpcode() == ISD::ADD) { 325 Base = Addr.getOperand(0); 326 Offset = Addr.getOperand(1); 327 return true; 328 } 329 330 return false; 331} 332 333bool MipsSEDAGToDAGISel::selectAddrDefault(SDValue Addr, SDValue &Base, 334 SDValue &Offset) const { 335 Base = Addr; 336 Offset = CurDAG->getTargetConstant(0, Addr.getValueType()); 337 return true; 338} 339 340bool MipsSEDAGToDAGISel::selectIntAddr(SDValue Addr, SDValue &Base, 341 SDValue &Offset) const { 342 return selectAddrRegImm(Addr, Base, Offset) || 343 selectAddrDefault(Addr, Base, Offset); 344} 345 346/// Used on microMIPS Load/Store unaligned instructions (12-bit offset) 347bool MipsSEDAGToDAGISel::selectAddrRegImm12(SDValue Addr, SDValue &Base, 348 SDValue &Offset) const { 349 EVT ValTy = Addr.getValueType(); 350 351 // Addresses of the form FI+const or FI|const 352 if (CurDAG->isBaseWithConstantOffset(Addr)) { 353 ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)); 354 if (isInt<12>(CN->getSExtValue())) { 355 356 // If the first operand is a FI then get the TargetFI Node 357 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode> 358 (Addr.getOperand(0))) 359 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy); 360 else 361 Base = Addr.getOperand(0); 362 363 Offset = CurDAG->getTargetConstant(CN->getZExtValue(), ValTy); 364 return true; 365 } 366 } 367 368 return false; 369} 370 371bool MipsSEDAGToDAGISel::selectIntAddrMM(SDValue Addr, SDValue &Base, 372 SDValue &Offset) const { 373 return selectAddrRegImm12(Addr, Base, Offset) || 374 selectAddrDefault(Addr, Base, Offset); 375} 376 377std::pair<bool, SDNode*> MipsSEDAGToDAGISel::selectNode(SDNode *Node) { 378 unsigned Opcode = Node->getOpcode(); 379 SDLoc DL(Node); 380 381 /// 382 // Instruction Selection not handled by the auto-generated 383 // tablegen selection should be handled here. 384 /// 385 SDNode *Result; 386 387 switch(Opcode) { 388 default: break; 389 390 case ISD::SUBE: { 391 SDValue InFlag = Node->getOperand(2); 392 Result = selectAddESubE(Mips::SUBu, InFlag, InFlag.getOperand(0), DL, Node); 393 return std::make_pair(true, Result); 394 } 395 396 case ISD::ADDE: { 397 if (Subtarget.hasDSP()) // Select DSP instructions, ADDSC and ADDWC. 398 break; 399 SDValue InFlag = Node->getOperand(2); 400 Result = selectAddESubE(Mips::ADDu, InFlag, InFlag.getValue(0), DL, Node); 401 return std::make_pair(true, Result); 402 } 403 404 case ISD::ConstantFP: { 405 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(Node); 406 if (Node->getValueType(0) == MVT::f64 && CN->isExactlyValue(+0.0)) { 407 if (Subtarget.hasMips64()) { 408 SDValue Zero = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), DL, 409 Mips::ZERO_64, MVT::i64); 410 Result = CurDAG->getMachineNode(Mips::DMTC1, DL, MVT::f64, Zero); 411 } else { 412 SDValue Zero = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), DL, 413 Mips::ZERO, MVT::i32); 414 Result = CurDAG->getMachineNode(Mips::BuildPairF64, DL, MVT::f64, Zero, 415 Zero); 416 } 417 418 return std::make_pair(true, Result); 419 } 420 break; 421 } 422 423 case ISD::Constant: { 424 const ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Node); 425 unsigned Size = CN->getValueSizeInBits(0); 426 427 if (Size == 32) 428 break; 429 430 MipsAnalyzeImmediate AnalyzeImm; 431 int64_t Imm = CN->getSExtValue(); 432 433 const MipsAnalyzeImmediate::InstSeq &Seq = 434 AnalyzeImm.Analyze(Imm, Size, false); 435 436 MipsAnalyzeImmediate::InstSeq::const_iterator Inst = Seq.begin(); 437 SDLoc DL(CN); 438 SDNode *RegOpnd; 439 SDValue ImmOpnd = CurDAG->getTargetConstant(SignExtend64<16>(Inst->ImmOpnd), 440 MVT::i64); 441 442 // The first instruction can be a LUi which is different from other 443 // instructions (ADDiu, ORI and SLL) in that it does not have a register 444 // operand. 445 if (Inst->Opc == Mips::LUi64) 446 RegOpnd = CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, ImmOpnd); 447 else 448 RegOpnd = 449 CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, 450 CurDAG->getRegister(Mips::ZERO_64, MVT::i64), 451 ImmOpnd); 452 453 // The remaining instructions in the sequence are handled here. 454 for (++Inst; Inst != Seq.end(); ++Inst) { 455 ImmOpnd = CurDAG->getTargetConstant(SignExtend64<16>(Inst->ImmOpnd), 456 MVT::i64); 457 RegOpnd = CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, 458 SDValue(RegOpnd, 0), ImmOpnd); 459 } 460 461 return std::make_pair(true, RegOpnd); 462 } 463 464 case ISD::INTRINSIC_W_CHAIN: { 465 switch (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) { 466 default: 467 break; 468 469 case Intrinsic::mips_cfcmsa: { 470 SDValue ChainIn = Node->getOperand(0); 471 SDValue RegIdx = Node->getOperand(2); 472 SDValue Reg = CurDAG->getCopyFromReg(ChainIn, DL, 473 getMSACtrlReg(RegIdx), MVT::i32); 474 return std::make_pair(true, Reg.getNode()); 475 } 476 } 477 break; 478 } 479 480 case ISD::INTRINSIC_WO_CHAIN: { 481 switch (cast<ConstantSDNode>(Node->getOperand(0))->getZExtValue()) { 482 default: 483 break; 484 485 case Intrinsic::mips_move_v: 486 // Like an assignment but will always produce a move.v even if 487 // unnecessary. 488 return std::make_pair(true, 489 CurDAG->getMachineNode(Mips::MOVE_V, DL, 490 Node->getValueType(0), 491 Node->getOperand(1))); 492 } 493 break; 494 } 495 496 case ISD::INTRINSIC_VOID: { 497 switch (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) { 498 default: 499 break; 500 501 case Intrinsic::mips_ctcmsa: { 502 SDValue ChainIn = Node->getOperand(0); 503 SDValue RegIdx = Node->getOperand(2); 504 SDValue Value = Node->getOperand(3); 505 SDValue ChainOut = CurDAG->getCopyToReg(ChainIn, DL, 506 getMSACtrlReg(RegIdx), Value); 507 return std::make_pair(true, ChainOut.getNode()); 508 } 509 } 510 break; 511 } 512 513 case MipsISD::ThreadPointer: { 514 EVT PtrVT = getTargetLowering()->getPointerTy(); 515 unsigned RdhwrOpc, DestReg; 516 517 if (PtrVT == MVT::i32) { 518 RdhwrOpc = Mips::RDHWR; 519 DestReg = Mips::V1; 520 } else { 521 RdhwrOpc = Mips::RDHWR64; 522 DestReg = Mips::V1_64; 523 } 524 525 SDNode *Rdhwr = 526 CurDAG->getMachineNode(RdhwrOpc, SDLoc(Node), 527 Node->getValueType(0), 528 CurDAG->getRegister(Mips::HWR29, MVT::i32)); 529 SDValue Chain = CurDAG->getCopyToReg(CurDAG->getEntryNode(), DL, DestReg, 530 SDValue(Rdhwr, 0)); 531 SDValue ResNode = CurDAG->getCopyFromReg(Chain, DL, DestReg, PtrVT); 532 ReplaceUses(SDValue(Node, 0), ResNode); 533 return std::make_pair(true, ResNode.getNode()); 534 } 535 536 case MipsISD::InsertLOHI: { 537 unsigned RCID = Subtarget.hasDSP() ? Mips::ACC64DSPRegClassID : 538 Mips::ACC64RegClassID; 539 SDValue RegClass = CurDAG->getTargetConstant(RCID, MVT::i32); 540 SDValue LoIdx = CurDAG->getTargetConstant(Mips::sub_lo, MVT::i32); 541 SDValue HiIdx = CurDAG->getTargetConstant(Mips::sub_hi, MVT::i32); 542 const SDValue Ops[] = { RegClass, Node->getOperand(0), LoIdx, 543 Node->getOperand(1), HiIdx }; 544 SDNode *Res = CurDAG->getMachineNode(TargetOpcode::REG_SEQUENCE, DL, 545 MVT::Untyped, Ops); 546 return std::make_pair(true, Res); 547 } 548 } 549 550 return std::make_pair(false, (SDNode*)NULL); 551} 552 553FunctionPass *llvm::createMipsSEISelDag(MipsTargetMachine &TM) { 554 return new MipsSEDAGToDAGISel(TM); 555} 556