lib/CodeGen/TargetInstrInfo.cpp

   1 //===-- TargetInstrInfo.cpp - Target Instruction Information --------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the TargetInstrInfo class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/CodeGen/TargetInstrInfo.h"
  14 #include "llvm/CodeGen/MachineFrameInfo.h"
  15 #include "llvm/CodeGen/MachineInstrBuilder.h"
  16 #include "llvm/CodeGen/MachineMemOperand.h"
  17 #include "llvm/CodeGen/MachineRegisterInfo.h"
  18 #include "llvm/CodeGen/PseudoSourceValue.h"
  19 #include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
  20 #include "llvm/CodeGen/StackMaps.h"
  21 #include "llvm/CodeGen/TargetFrameLowering.h"
  22 #include "llvm/CodeGen/TargetLowering.h"
  23 #include "llvm/CodeGen/TargetRegisterInfo.h"
  24 #include "llvm/CodeGen/TargetSchedule.h"
  25 #include "llvm/IR/DataLayout.h"
  26 #include "llvm/IR/DebugInfoMetadata.h"
  27 #include "llvm/MC/MCAsmInfo.h"
  28 #include "llvm/MC/MCInstrItineraries.h"
  29 #include "llvm/Support/CommandLine.h"
  30 #include "llvm/Support/ErrorHandling.h"
  31 #include "llvm/Support/raw_ostream.h"
  32 #include "llvm/Target/TargetMachine.h"
  33 #include <cctype>
  34
  35 using namespace llvm;
  36
  37 static cl::opt<bool> DisableHazardRecognizer(
  38   "disable-sched-hazard", cl::Hidden, cl::init(false),
  39   cl::desc("Disable hazard detection during preRA scheduling"));
  40
  41 TargetInstrInfo::~TargetInstrInfo() {
  42 }
  43
  44 const TargetRegisterClass*
  45 TargetInstrInfo::getRegClass(const MCInstrDesc &MCID, unsigned OpNum,
  46                              const TargetRegisterInfo *TRI,
  47                              const MachineFunction &MF) const {
  48   if (OpNum >= MCID.getNumOperands())
  49     return nullptr;
  50
  51   short RegClass = MCID.OpInfo[OpNum].RegClass;
  52   if (MCID.OpInfo[OpNum].isLookupPtrRegClass())
  53     return TRI->getPointerRegClass(MF, RegClass);
  54
  55   // Instructions like INSERT_SUBREG do not have fixed register classes.
  56   if (RegClass < 0)
  57     return nullptr;
  58
  59   // Otherwise just look it up normally.
  60   return TRI->getRegClass(RegClass);
  61 }
  62
  63 /// insertNoop - Insert a noop into the instruction stream at the specified
  64 /// point.
  65 void TargetInstrInfo::insertNoop(MachineBasicBlock &MBB,
  66                                  MachineBasicBlock::iterator MI) const {
  67   llvm_unreachable("Target didn't implement insertNoop!");
  68 }
  69
  70 static bool isAsmComment(const char *Str, const MCAsmInfo &MAI) {
  71   return strncmp(Str, MAI.getCommentString().data(),
  72                  MAI.getCommentString().size()) == 0;
  73 }
  74
  75 /// Measure the specified inline asm to determine an approximation of its
  76 /// length.
  77 /// Comments (which run till the next SeparatorString or newline) do not
  78 /// count as an instruction.
  79 /// Any other non-whitespace text is considered an instruction, with
  80 /// multiple instructions separated by SeparatorString or newlines.
  81 /// Variable-length instructions are not handled here; this function
  82 /// may be overloaded in the target code to do that.
  83 /// We implement a special case of the .space directive which takes only a
  84 /// single integer argument in base 10 that is the size in bytes. This is a
  85 /// restricted form of the GAS directive in that we only interpret
  86 /// simple--i.e. not a logical or arithmetic expression--size values without
  87 /// the optional fill value. This is primarily used for creating arbitrary
  88 /// sized inline asm blocks for testing purposes.
  89 unsigned TargetInstrInfo::getInlineAsmLength(
  90   const char *Str,
  91   const MCAsmInfo &MAI, const TargetSubtargetInfo *STI) const {
  92   // Count the number of instructions in the asm.
  93   bool AtInsnStart = true;
  94   unsigned Length = 0;
  95   const unsigned MaxInstLength = MAI.getMaxInstLength(STI);
  96   for (; *Str; ++Str) {
  97     if (*Str == '\n' || strncmp(Str, MAI.getSeparatorString(),
  98                                 strlen(MAI.getSeparatorString())) == 0) {
  99       AtInsnStart = true;
 100     } else if (isAsmComment(Str, MAI)) {
 101       // Stop counting as an instruction after a comment until the next
 102       // separator.
 103       AtInsnStart = false;
 104     }
 105
 106     if (AtInsnStart && !std::isspace(static_cast<unsigned char>(*Str))) {
 107       unsigned AddLength = MaxInstLength;
 108       if (strncmp(Str, ".space", 6) == 0) {
 109         char *EStr;
 110         int SpaceSize;
 111         SpaceSize = strtol(Str + 6, &EStr, 10);
 112         SpaceSize = SpaceSize < 0 ? 0 : SpaceSize;
 113         while (*EStr != '\n' && std::isspace(static_cast<unsigned char>(*EStr)))
 114           ++EStr;
 115         if (*EStr == '\0' || *EStr == '\n' ||
 116             isAsmComment(EStr, MAI)) // Successfully parsed .space argument
 117           AddLength = SpaceSize;
 118       }
 119       Length += AddLength;
 120       AtInsnStart = false;
 121     }
 122   }
 123
 124   return Length;
 125 }
 126
 127 /// ReplaceTailWithBranchTo - Delete the instruction OldInst and everything
 128 /// after it, replacing it with an unconditional branch to NewDest.
 129 void
 130 TargetInstrInfo::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
 131                                          MachineBasicBlock *NewDest) const {
 132   MachineBasicBlock *MBB = Tail->getParent();
 133
 134   // Remove all the old successors of MBB from the CFG.
 135   while (!MBB->succ_empty())
 136     MBB->removeSuccessor(MBB->succ_begin());
 137
 138   // Save off the debug loc before erasing the instruction.
 139   DebugLoc DL = Tail->getDebugLoc();
 140
 141   // Update call site info and remove all the dead instructions
 142   // from the end of MBB.
 143   while (Tail != MBB->end()) {
 144     auto MI = Tail++;
 145     if (MI->isCall())
 146       MBB->getParent()->eraseCallSiteInfo(&*MI);
 147     MBB->erase(MI);
 148   }
 149
 150   // If MBB isn't immediately before MBB, insert a branch to it.
 151   if (++MachineFunction::iterator(MBB) != MachineFunction::iterator(NewDest))
 152     insertBranch(*MBB, NewDest, nullptr, SmallVector<MachineOperand, 0>(), DL);
 153   MBB->addSuccessor(NewDest);
 154 }
 155
 156 MachineInstr *TargetInstrInfo::commuteInstructionImpl(MachineInstr &MI,
 157                                                       bool NewMI, unsigned Idx1,
 158                                                       unsigned Idx2) const {
 159   const MCInstrDesc &MCID = MI.getDesc();
 160   bool HasDef = MCID.getNumDefs();
 161   if (HasDef && !MI.getOperand(0).isReg())
 162     // No idea how to commute this instruction. Target should implement its own.
 163     return nullptr;
 164
 165   unsigned CommutableOpIdx1 = Idx1; (void)CommutableOpIdx1;
 166   unsigned CommutableOpIdx2 = Idx2; (void)CommutableOpIdx2;
 167   assert(findCommutedOpIndices(MI, CommutableOpIdx1, CommutableOpIdx2) &&
 168          CommutableOpIdx1 == Idx1 && CommutableOpIdx2 == Idx2 &&
 169          "TargetInstrInfo::CommuteInstructionImpl(): not commutable operands.");
 170   assert(MI.getOperand(Idx1).isReg() && MI.getOperand(Idx2).isReg() &&
 171          "This only knows how to commute register operands so far");
 172
 173   Register Reg0 = HasDef ? MI.getOperand(0).getReg() : Register();
 174   Register Reg1 = MI.getOperand(Idx1).getReg();
 175   Register Reg2 = MI.getOperand(Idx2).getReg();
 176   unsigned SubReg0 = HasDef ? MI.getOperand(0).getSubReg() : 0;
 177   unsigned SubReg1 = MI.getOperand(Idx1).getSubReg();
 178   unsigned SubReg2 = MI.getOperand(Idx2).getSubReg();
 179   bool Reg1IsKill = MI.getOperand(Idx1).isKill();
 180   bool Reg2IsKill = MI.getOperand(Idx2).isKill();
 181   bool Reg1IsUndef = MI.getOperand(Idx1).isUndef();
 182   bool Reg2IsUndef = MI.getOperand(Idx2).isUndef();
 183   bool Reg1IsInternal = MI.getOperand(Idx1).isInternalRead();
 184   bool Reg2IsInternal = MI.getOperand(Idx2).isInternalRead();
 185   // Avoid calling isRenamable for virtual registers since we assert that
 186   // renamable property is only queried/set for physical registers.
 187   bool Reg1IsRenamable = Register::isPhysicalRegister(Reg1)
 188                              ? MI.getOperand(Idx1).isRenamable()
 189                              : false;
 190   bool Reg2IsRenamable = Register::isPhysicalRegister(Reg2)
 191                              ? MI.getOperand(Idx2).isRenamable()
 192                              : false;
 193   // If destination is tied to either of the commuted source register, then
 194   // it must be updated.
 195   if (HasDef && Reg0 == Reg1 &&
 196       MI.getDesc().getOperandConstraint(Idx1, MCOI::TIED_TO) == 0) {
 197     Reg2IsKill = false;
 198     Reg0 = Reg2;
 199     SubReg0 = SubReg2;
 200   } else if (HasDef && Reg0 == Reg2 &&
 201              MI.getDesc().getOperandConstraint(Idx2, MCOI::TIED_TO) == 0) {
 202     Reg1IsKill = false;
 203     Reg0 = Reg1;
 204     SubReg0 = SubReg1;
 205   }
 206
 207   MachineInstr *CommutedMI = nullptr;
 208   if (NewMI) {
 209     // Create a new instruction.
 210     MachineFunction &MF = *MI.getMF();
 211     CommutedMI = MF.CloneMachineInstr(&MI);
 212   } else {
 213     CommutedMI = &MI;
 214   }
 215
 216   if (HasDef) {
 217     CommutedMI->getOperand(0).setReg(Reg0);
 218     CommutedMI->getOperand(0).setSubReg(SubReg0);
 219   }
 220   CommutedMI->getOperand(Idx2).setReg(Reg1);
 221   CommutedMI->getOperand(Idx1).setReg(Reg2);
 222   CommutedMI->getOperand(Idx2).setSubReg(SubReg1);
 223   CommutedMI->getOperand(Idx1).setSubReg(SubReg2);
 224   CommutedMI->getOperand(Idx2).setIsKill(Reg1IsKill);
 225   CommutedMI->getOperand(Idx1).setIsKill(Reg2IsKill);
 226   CommutedMI->getOperand(Idx2).setIsUndef(Reg1IsUndef);
 227   CommutedMI->getOperand(Idx1).setIsUndef(Reg2IsUndef);
 228   CommutedMI->getOperand(Idx2).setIsInternalRead(Reg1IsInternal);
 229   CommutedMI->getOperand(Idx1).setIsInternalRead(Reg2IsInternal);
 230   // Avoid calling setIsRenamable for virtual registers since we assert that
 231   // renamable property is only queried/set for physical registers.
 232   if (Register::isPhysicalRegister(Reg1))
 233     CommutedMI->getOperand(Idx2).setIsRenamable(Reg1IsRenamable);
 234   if (Register::isPhysicalRegister(Reg2))
 235     CommutedMI->getOperand(Idx1).setIsRenamable(Reg2IsRenamable);
 236   return CommutedMI;
 237 }
 238
 239 MachineInstr *TargetInstrInfo::commuteInstruction(MachineInstr &MI, bool NewMI,
 240                                                   unsigned OpIdx1,
 241                                                   unsigned OpIdx2) const {
 242   // If OpIdx1 or OpIdx2 is not specified, then this method is free to choose
 243   // any commutable operand, which is done in findCommutedOpIndices() method
 244   // called below.
 245   if ((OpIdx1 == CommuteAnyOperandIndex || OpIdx2 == CommuteAnyOperandIndex) &&
 246       !findCommutedOpIndices(MI, OpIdx1, OpIdx2)) {
 247     assert(MI.isCommutable() &&
 248            "Precondition violation: MI must be commutable.");
 249     return nullptr;
 250   }
 251   return commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
 252 }
 253
 254 bool TargetInstrInfo::fixCommutedOpIndices(unsigned &ResultIdx1,
 255                                            unsigned &ResultIdx2,
 256                                            unsigned CommutableOpIdx1,
 257                                            unsigned CommutableOpIdx2) {
 258   if (ResultIdx1 == CommuteAnyOperandIndex &&
 259       ResultIdx2 == CommuteAnyOperandIndex) {
 260     ResultIdx1 = CommutableOpIdx1;
 261     ResultIdx2 = CommutableOpIdx2;
 262   } else if (ResultIdx1 == CommuteAnyOperandIndex) {
 263     if (ResultIdx2 == CommutableOpIdx1)
 264       ResultIdx1 = CommutableOpIdx2;
 265     else if (ResultIdx2 == CommutableOpIdx2)
 266       ResultIdx1 = CommutableOpIdx1;
 267     else
 268       return false;
 269   } else if (ResultIdx2 == CommuteAnyOperandIndex) {
 270     if (ResultIdx1 == CommutableOpIdx1)
 271       ResultIdx2 = CommutableOpIdx2;
 272     else if (ResultIdx1 == CommutableOpIdx2)
 273       ResultIdx2 = CommutableOpIdx1;
 274     else
 275       return false;
 276   } else
 277     // Check that the result operand indices match the given commutable
 278     // operand indices.
 279     return (ResultIdx1 == CommutableOpIdx1 && ResultIdx2 == CommutableOpIdx2) ||
 280            (ResultIdx1 == CommutableOpIdx2 && ResultIdx2 == CommutableOpIdx1);
 281
 282   return true;
 283 }
 284
 285 bool TargetInstrInfo::findCommutedOpIndices(const MachineInstr &MI,
 286                                             unsigned &SrcOpIdx1,
 287                                             unsigned &SrcOpIdx2) const {
 288   assert(!MI.isBundle() &&
 289          "TargetInstrInfo::findCommutedOpIndices() can't handle bundles");
 290
 291   const MCInstrDesc &MCID = MI.getDesc();
 292   if (!MCID.isCommutable())
 293     return false;
 294
 295   // This assumes v0 = op v1, v2 and commuting would swap v1 and v2. If this
 296   // is not true, then the target must implement this.
 297   unsigned CommutableOpIdx1 = MCID.getNumDefs();
 298   unsigned CommutableOpIdx2 = CommutableOpIdx1 + 1;
 299   if (!fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2,
 300                             CommutableOpIdx1, CommutableOpIdx2))
 301     return false;
 302
 303   if (!MI.getOperand(SrcOpIdx1).isReg() || !MI.getOperand(SrcOpIdx2).isReg())
 304     // No idea.
 305     return false;
 306   return true;
 307 }
 308
 309 bool TargetInstrInfo::isUnpredicatedTerminator(const MachineInstr &MI) const {
 310   if (!MI.isTerminator()) return false;
 311
 312   // Conditional branch is a special case.
 313   if (MI.isBranch() && !MI.isBarrier())
 314     return true;
 315   if (!MI.isPredicable())
 316     return true;
 317   return !isPredicated(MI);
 318 }
 319
 320 bool TargetInstrInfo::PredicateInstruction(
 321     MachineInstr &MI, ArrayRef<MachineOperand> Pred) const {
 322   bool MadeChange = false;
 323
 324   assert(!MI.isBundle() &&
 325          "TargetInstrInfo::PredicateInstruction() can't handle bundles");
 326
 327   const MCInstrDesc &MCID = MI.getDesc();
 328   if (!MI.isPredicable())
 329     return false;
 330
 331   for (unsigned j = 0, i = 0, e = MI.getNumOperands(); i != e; ++i) {
 332     if (MCID.OpInfo[i].isPredicate()) {
 333       MachineOperand &MO = MI.getOperand(i);
 334       if (MO.isReg()) {
 335         MO.setReg(Pred[j].getReg());
 336         MadeChange = true;
 337       } else if (MO.isImm()) {
 338         MO.setImm(Pred[j].getImm());
 339         MadeChange = true;
 340       } else if (MO.isMBB()) {
 341         MO.setMBB(Pred[j].getMBB());
 342         MadeChange = true;
 343       }
 344       ++j;
 345     }
 346   }
 347   return MadeChange;
 348 }
 349
 350 bool TargetInstrInfo::hasLoadFromStackSlot(
 351     const MachineInstr &MI,
 352     SmallVectorImpl<const MachineMemOperand *> &Accesses) const {
 353   size_t StartSize = Accesses.size();
 354   for (MachineInstr::mmo_iterator o = MI.memoperands_begin(),
 355                                   oe = MI.memoperands_end();
 356        o != oe; ++o) {
 357     if ((*o)->isLoad() &&
 358         dyn_cast_or_null<FixedStackPseudoSourceValue>((*o)->getPseudoValue()))
 359       Accesses.push_back(*o);
 360   }
 361   return Accesses.size() != StartSize;
 362 }
 363
 364 bool TargetInstrInfo::hasStoreToStackSlot(
 365     const MachineInstr &MI,
 366     SmallVectorImpl<const MachineMemOperand *> &Accesses) const {
 367   size_t StartSize = Accesses.size();
 368   for (MachineInstr::mmo_iterator o = MI.memoperands_begin(),
 369                                   oe = MI.memoperands_end();
 370        o != oe; ++o) {
 371     if ((*o)->isStore() &&
 372         dyn_cast_or_null<FixedStackPseudoSourceValue>((*o)->getPseudoValue()))
 373       Accesses.push_back(*o);
 374   }
 375   return Accesses.size() != StartSize;
 376 }
 377
 378 bool TargetInstrInfo::getStackSlotRange(const TargetRegisterClass *RC,
 379                                         unsigned SubIdx, unsigned &Size,
 380                                         unsigned &Offset,
 381                                         const MachineFunction &MF) const {
 382   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
 383   if (!SubIdx) {
 384     Size = TRI->getSpillSize(*RC);
 385     Offset = 0;
 386     return true;
 387   }
 388   unsigned BitSize = TRI->getSubRegIdxSize(SubIdx);
 389   // Convert bit size to byte size.
 390   if (BitSize % 8)
 391     return false;
 392
 393   int BitOffset = TRI->getSubRegIdxOffset(SubIdx);
 394   if (BitOffset < 0 || BitOffset % 8)
 395     return false;
 396
 397   Size = BitSize / 8;
 398   Offset = (unsigned)BitOffset / 8;
 399
 400   assert(TRI->getSpillSize(*RC) >= (Offset + Size) && "bad subregister range");
 401
 402   if (!MF.getDataLayout().isLittleEndian()) {
 403     Offset = TRI->getSpillSize(*RC) - (Offset + Size);
 404   }
 405   return true;
 406 }
 407
 408 void TargetInstrInfo::reMaterialize(MachineBasicBlock &MBB,
 409                                     MachineBasicBlock::iterator I,
 410                                     unsigned DestReg, unsigned SubIdx,
 411                                     const MachineInstr &Orig,
 412                                     const TargetRegisterInfo &TRI) const {
 413   MachineInstr *MI = MBB.getParent()->CloneMachineInstr(&Orig);
 414   MI->substituteRegister(MI->getOperand(0).getReg(), DestReg, SubIdx, TRI);
 415   MBB.insert(I, MI);
 416 }
 417
 418 bool TargetInstrInfo::produceSameValue(const MachineInstr &MI0,
 419                                        const MachineInstr &MI1,
 420                                        const MachineRegisterInfo *MRI) const {
 421   return MI0.isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
 422 }
 423
 424 MachineInstr &TargetInstrInfo::duplicate(MachineBasicBlock &MBB,
 425     MachineBasicBlock::iterator InsertBefore, const MachineInstr &Orig) const {
 426   assert(!Orig.isNotDuplicable() && "Instruction cannot be duplicated");
 427   MachineFunction &MF = *MBB.getParent();
 428   return MF.CloneMachineInstrBundle(MBB, InsertBefore, Orig);
 429 }
 430
 431 // If the COPY instruction in MI can be folded to a stack operation, return
 432 // the register class to use.
 433 static const TargetRegisterClass *canFoldCopy(const MachineInstr &MI,
 434                                               unsigned FoldIdx) {
 435   assert(MI.isCopy() && "MI must be a COPY instruction");
 436   if (MI.getNumOperands() != 2)
 437     return nullptr;
 438   assert(FoldIdx<2 && "FoldIdx refers no nonexistent operand");
 439
 440   const MachineOperand &FoldOp = MI.getOperand(FoldIdx);
 441   const MachineOperand &LiveOp = MI.getOperand(1 - FoldIdx);
 442
 443   if (FoldOp.getSubReg() || LiveOp.getSubReg())
 444     return nullptr;
 445
 446   Register FoldReg = FoldOp.getReg();
 447   Register LiveReg = LiveOp.getReg();
 448
 449   assert(Register::isVirtualRegister(FoldReg) && "Cannot fold physregs");
 450
 451   const MachineRegisterInfo &MRI = MI.getMF()->getRegInfo();
 452   const TargetRegisterClass *RC = MRI.getRegClass(FoldReg);
 453
 454   if (Register::isPhysicalRegister(LiveOp.getReg()))
 455     return RC->contains(LiveOp.getReg()) ? RC : nullptr;
 456
 457   if (RC->hasSubClassEq(MRI.getRegClass(LiveReg)))
 458     return RC;
 459
 460   // FIXME: Allow folding when register classes are memory compatible.
 461   return nullptr;
 462 }
 463
 464 void TargetInstrInfo::getNoop(MCInst &NopInst) const {
 465   llvm_unreachable("Not implemented");
 466 }
 467
 468 static MachineInstr *foldPatchpoint(MachineFunction &MF, MachineInstr &MI,
 469                                     ArrayRef<unsigned> Ops, int FrameIndex,
 470                                     const TargetInstrInfo &TII) {
 471   unsigned StartIdx = 0;
 472   switch (MI.getOpcode()) {
 473   case TargetOpcode::STACKMAP: {
 474     // StackMapLiveValues are foldable
 475     StartIdx = StackMapOpers(&MI).getVarIdx();
 476     break;
 477   }
 478   case TargetOpcode::PATCHPOINT: {
 479     // For PatchPoint, the call args are not foldable (even if reported in the
 480     // stackmap e.g. via anyregcc).
 481     StartIdx = PatchPointOpers(&MI).getVarIdx();
 482     break;
 483   }
 484   case TargetOpcode::STATEPOINT: {
 485     // For statepoints, fold deopt and gc arguments, but not call arguments.
 486     StartIdx = StatepointOpers(&MI).getVarIdx();
 487     break;
 488   }
 489   default:
 490     llvm_unreachable("unexpected stackmap opcode");
 491   }
 492
 493   // Return false if any operands requested for folding are not foldable (not
 494   // part of the stackmap's live values).
 495   for (unsigned Op : Ops) {
 496     if (Op < StartIdx)
 497       return nullptr;
 498   }
 499
 500   MachineInstr *NewMI =
 501       MF.CreateMachineInstr(TII.get(MI.getOpcode()), MI.getDebugLoc(), true);
 502   MachineInstrBuilder MIB(MF, NewMI);
 503
 504   // No need to fold return, the meta data, and function arguments
 505   for (unsigned i = 0; i < StartIdx; ++i)
 506     MIB.add(MI.getOperand(i));
 507
 508   for (unsigned i = StartIdx; i < MI.getNumOperands(); ++i) {
 509     MachineOperand &MO = MI.getOperand(i);
 510     if (is_contained(Ops, i)) {
 511       unsigned SpillSize;
 512       unsigned SpillOffset;
 513       // Compute the spill slot size and offset.
 514       const TargetRegisterClass *RC =
 515         MF.getRegInfo().getRegClass(MO.getReg());
 516       bool Valid =
 517           TII.getStackSlotRange(RC, MO.getSubReg(), SpillSize, SpillOffset, MF);
 518       if (!Valid)
 519         report_fatal_error("cannot spill patchpoint subregister operand");
 520       MIB.addImm(StackMaps::IndirectMemRefOp);
 521       MIB.addImm(SpillSize);
 522       MIB.addFrameIndex(FrameIndex);
 523       MIB.addImm(SpillOffset);
 524     }
 525     else
 526       MIB.add(MO);
 527   }
 528   return NewMI;
 529 }
 530
 531 MachineInstr *TargetInstrInfo::foldMemoryOperand(MachineInstr &MI,
 532                                                  ArrayRef<unsigned> Ops, int FI,
 533                                                  LiveIntervals *LIS,
 534                                                  VirtRegMap *VRM) const {
 535   auto Flags = MachineMemOperand::MONone;
 536   for (unsigned OpIdx : Ops)
 537     Flags |= MI.getOperand(OpIdx).isDef() ? MachineMemOperand::MOStore
 538                                           : MachineMemOperand::MOLoad;
 539
 540   MachineBasicBlock *MBB = MI.getParent();
 541   assert(MBB && "foldMemoryOperand needs an inserted instruction");
 542   MachineFunction &MF = *MBB->getParent();
 543
 544   // If we're not folding a load into a subreg, the size of the load is the
 545   // size of the spill slot. But if we are, we need to figure out what the
 546   // actual load size is.
 547   int64_t MemSize = 0;
 548   const MachineFrameInfo &MFI = MF.getFrameInfo();
 549   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
 550
 551   if (Flags & MachineMemOperand::MOStore) {
 552     MemSize = MFI.getObjectSize(FI);
 553   } else {
 554     for (unsigned OpIdx : Ops) {
 555       int64_t OpSize = MFI.getObjectSize(FI);
 556
 557       if (auto SubReg = MI.getOperand(OpIdx).getSubReg()) {
 558         unsigned SubRegSize = TRI->getSubRegIdxSize(SubReg);
 559         if (SubRegSize > 0 && !(SubRegSize % 8))
 560           OpSize = SubRegSize / 8;
 561       }
 562
 563       MemSize = std::max(MemSize, OpSize);
 564     }
 565   }
 566
 567   assert(MemSize && "Did not expect a zero-sized stack slot");
 568
 569   MachineInstr *NewMI = nullptr;
 570
 571   if (MI.getOpcode() == TargetOpcode::STACKMAP ||
 572       MI.getOpcode() == TargetOpcode::PATCHPOINT ||
 573       MI.getOpcode() == TargetOpcode::STATEPOINT) {
 574     // Fold stackmap/patchpoint.
 575     NewMI = foldPatchpoint(MF, MI, Ops, FI, *this);
 576     if (NewMI)
 577       MBB->insert(MI, NewMI);
 578   } else {
 579     // Ask the target to do the actual folding.
 580     NewMI = foldMemoryOperandImpl(MF, MI, Ops, MI, FI, LIS, VRM);
 581   }
 582
 583   if (NewMI) {
 584     NewMI->setMemRefs(MF, MI.memoperands());
 585     // Add a memory operand, foldMemoryOperandImpl doesn't do that.
 586     assert((!(Flags & MachineMemOperand::MOStore) ||
 587             NewMI->mayStore()) &&
 588            "Folded a def to a non-store!");
 589     assert((!(Flags & MachineMemOperand::MOLoad) ||
 590             NewMI->mayLoad()) &&
 591            "Folded a use to a non-load!");
 592     assert(MFI.getObjectOffset(FI) != -1);
 593     MachineMemOperand *MMO = MF.getMachineMemOperand(
 594         MachinePointerInfo::getFixedStack(MF, FI), Flags, MemSize,
 595         MFI.getObjectAlignment(FI));
 596     NewMI->addMemOperand(MF, MMO);
 597
 598     return NewMI;
 599   }
 600
 601   // Straight COPY may fold as load/store.
 602   if (!MI.isCopy() || Ops.size() != 1)
 603     return nullptr;
 604
 605   const TargetRegisterClass *RC = canFoldCopy(MI, Ops[0]);
 606   if (!RC)
 607     return nullptr;
 608
 609   const MachineOperand &MO = MI.getOperand(1 - Ops[0]);
 610   MachineBasicBlock::iterator Pos = MI;
 611
 612   if (Flags == MachineMemOperand::MOStore)
 613     storeRegToStackSlot(*MBB, Pos, MO.getReg(), MO.isKill(), FI, RC, TRI);
 614   else
 615     loadRegFromStackSlot(*MBB, Pos, MO.getReg(), FI, RC, TRI);
 616   return &*--Pos;
 617 }
 618
 619 MachineInstr *TargetInstrInfo::foldMemoryOperand(MachineInstr &MI,
 620                                                  ArrayRef<unsigned> Ops,
 621                                                  MachineInstr &LoadMI,
 622                                                  LiveIntervals *LIS) const {
 623   assert(LoadMI.canFoldAsLoad() && "LoadMI isn't foldable!");
 624 #ifndef NDEBUG
 625   for (unsigned OpIdx : Ops)
 626     assert(MI.getOperand(OpIdx).isUse() && "Folding load into def!");
 627 #endif
 628
 629   MachineBasicBlock &MBB = *MI.getParent();
 630   MachineFunction &MF = *MBB.getParent();
 631
 632   // Ask the target to do the actual folding.
 633   MachineInstr *NewMI = nullptr;
 634   int FrameIndex = 0;
 635
 636   if ((MI.getOpcode() == TargetOpcode::STACKMAP ||
 637        MI.getOpcode() == TargetOpcode::PATCHPOINT ||
 638        MI.getOpcode() == TargetOpcode::STATEPOINT) &&
 639       isLoadFromStackSlot(LoadMI, FrameIndex)) {
 640     // Fold stackmap/patchpoint.
 641     NewMI = foldPatchpoint(MF, MI, Ops, FrameIndex, *this);
 642     if (NewMI)
 643       NewMI = &*MBB.insert(MI, NewMI);
 644   } else {
 645     // Ask the target to do the actual folding.
 646     NewMI = foldMemoryOperandImpl(MF, MI, Ops, MI, LoadMI, LIS);
 647   }
 648
 649   if (!NewMI)
 650     return nullptr;
 651
 652   // Copy the memoperands from the load to the folded instruction.
 653   if (MI.memoperands_empty()) {
 654     NewMI->setMemRefs(MF, LoadMI.memoperands());
 655   } else {
 656     // Handle the rare case of folding multiple loads.
 657     NewMI->setMemRefs(MF, MI.memoperands());
 658     for (MachineInstr::mmo_iterator I = LoadMI.memoperands_begin(),
 659                                     E = LoadMI.memoperands_end();
 660          I != E; ++I) {
 661       NewMI->addMemOperand(MF, *I);
 662     }
 663   }
 664   return NewMI;
 665 }
 666
 667 bool TargetInstrInfo::hasReassociableOperands(
 668     const MachineInstr &Inst, const MachineBasicBlock *MBB) const {
 669   const MachineOperand &Op1 = Inst.getOperand(1);
 670   const MachineOperand &Op2 = Inst.getOperand(2);
 671   const MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
 672
 673   // We need virtual register definitions for the operands that we will
 674   // reassociate.
 675   MachineInstr *MI1 = nullptr;
 676   MachineInstr *MI2 = nullptr;
 677   if (Op1.isReg() && Register::isVirtualRegister(Op1.getReg()))
 678     MI1 = MRI.getUniqueVRegDef(Op1.getReg());
 679   if (Op2.isReg() && Register::isVirtualRegister(Op2.getReg()))
 680     MI2 = MRI.getUniqueVRegDef(Op2.getReg());
 681
 682   // And they need to be in the trace (otherwise, they won't have a depth).
 683   return MI1 && MI2 && MI1->getParent() == MBB && MI2->getParent() == MBB;
 684 }
 685
 686 bool TargetInstrInfo::hasReassociableSibling(const MachineInstr &Inst,
 687                                              bool &Commuted) const {
 688   const MachineBasicBlock *MBB = Inst.getParent();
 689   const MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
 690   MachineInstr *MI1 = MRI.getUniqueVRegDef(Inst.getOperand(1).getReg());
 691   MachineInstr *MI2 = MRI.getUniqueVRegDef(Inst.getOperand(2).getReg());
 692   unsigned AssocOpcode = Inst.getOpcode();
 693
 694   // If only one operand has the same opcode and it's the second source operand,
 695   // the operands must be commuted.
 696   Commuted = MI1->getOpcode() != AssocOpcode && MI2->getOpcode() == AssocOpcode;
 697   if (Commuted)
 698     std::swap(MI1, MI2);
 699
 700   // 1. The previous instruction must be the same type as Inst.
 701   // 2. The previous instruction must have virtual register definitions for its
 702   //    operands in the same basic block as Inst.
 703   // 3. The previous instruction's result must only be used by Inst.
 704   return MI1->getOpcode() == AssocOpcode &&
 705          hasReassociableOperands(*MI1, MBB) &&
 706          MRI.hasOneNonDBGUse(MI1->getOperand(0).getReg());
 707 }
 708
 709 // 1. The operation must be associative and commutative.
 710 // 2. The instruction must have virtual register definitions for its
 711 //    operands in the same basic block.
 712 // 3. The instruction must have a reassociable sibling.
 713 bool TargetInstrInfo::isReassociationCandidate(const MachineInstr &Inst,
 714                                                bool &Commuted) const {
 715   return isAssociativeAndCommutative(Inst) &&
 716          hasReassociableOperands(Inst, Inst.getParent()) &&
 717          hasReassociableSibling(Inst, Commuted);
 718 }
 719
 720 // The concept of the reassociation pass is that these operations can benefit
 721 // from this kind of transformation:
 722 //
 723 // A = ? op ?
 724 // B = A op X (Prev)
 725 // C = B op Y (Root)
 726 // -->
 727 // A = ? op ?
 728 // B = X op Y
 729 // C = A op B
 730 //
 731 // breaking the dependency between A and B, allowing them to be executed in
 732 // parallel (or back-to-back in a pipeline) instead of depending on each other.
 733
 734 // FIXME: This has the potential to be expensive (compile time) while not
 735 // improving the code at all. Some ways to limit the overhead:
 736 // 1. Track successful transforms; bail out if hit rate gets too low.
 737 // 2. Only enable at -O3 or some other non-default optimization level.
 738 // 3. Pre-screen pattern candidates here: if an operand of the previous
 739 //    instruction is known to not increase the critical path, then don't match
 740 //    that pattern.
 741 bool TargetInstrInfo::getMachineCombinerPatterns(
 742     MachineInstr &Root,
 743     SmallVectorImpl<MachineCombinerPattern> &Patterns) const {
 744   bool Commute;
 745   if (isReassociationCandidate(Root, Commute)) {
 746     // We found a sequence of instructions that may be suitable for a
 747     // reassociation of operands to increase ILP. Specify each commutation
 748     // possibility for the Prev instruction in the sequence and let the
 749     // machine combiner decide if changing the operands is worthwhile.
 750     if (Commute) {
 751       Patterns.push_back(MachineCombinerPattern::REASSOC_AX_YB);
 752       Patterns.push_back(MachineCombinerPattern::REASSOC_XA_YB);
 753     } else {
 754       Patterns.push_back(MachineCombinerPattern::REASSOC_AX_BY);
 755       Patterns.push_back(MachineCombinerPattern::REASSOC_XA_BY);
 756     }
 757     return true;
 758   }
 759
 760   return false;
 761 }
 762
 763 /// Return true when a code sequence can improve loop throughput.
 764 bool
 765 TargetInstrInfo::isThroughputPattern(MachineCombinerPattern Pattern) const {
 766   return false;
 767 }
 768
 769 /// Attempt the reassociation transformation to reduce critical path length.
 770 /// See the above comments before getMachineCombinerPatterns().
 771 void TargetInstrInfo::reassociateOps(
 772     MachineInstr &Root, MachineInstr &Prev,
 773     MachineCombinerPattern Pattern,
 774     SmallVectorImpl<MachineInstr *> &InsInstrs,
 775     SmallVectorImpl<MachineInstr *> &DelInstrs,
 776     DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const {
 777   MachineFunction *MF = Root.getMF();
 778   MachineRegisterInfo &MRI = MF->getRegInfo();
 779   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
 780   const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
 781   const TargetRegisterClass *RC = Root.getRegClassConstraint(0, TII, TRI);
 782
 783   // This array encodes the operand index for each parameter because the
 784   // operands may be commuted. Each row corresponds to a pattern value,
 785   // and each column specifies the index of A, B, X, Y.
 786   unsigned OpIdx[4][4] = {
 787     { 1, 1, 2, 2 },
 788     { 1, 2, 2, 1 },
 789     { 2, 1, 1, 2 },
 790     { 2, 2, 1, 1 }
 791   };
 792
 793   int Row;
 794   switch (Pattern) {
 795   case MachineCombinerPattern::REASSOC_AX_BY: Row = 0; break;
 796   case MachineCombinerPattern::REASSOC_AX_YB: Row = 1; break;
 797   case MachineCombinerPattern::REASSOC_XA_BY: Row = 2; break;
 798   case MachineCombinerPattern::REASSOC_XA_YB: Row = 3; break;
 799   default: llvm_unreachable("unexpected MachineCombinerPattern");
 800   }
 801
 802   MachineOperand &OpA = Prev.getOperand(OpIdx[Row][0]);
 803   MachineOperand &OpB = Root.getOperand(OpIdx[Row][1]);
 804   MachineOperand &OpX = Prev.getOperand(OpIdx[Row][2]);
 805   MachineOperand &OpY = Root.getOperand(OpIdx[Row][3]);
 806   MachineOperand &OpC = Root.getOperand(0);
 807
 808   Register RegA = OpA.getReg();
 809   Register RegB = OpB.getReg();
 810   Register RegX = OpX.getReg();
 811   Register RegY = OpY.getReg();
 812   Register RegC = OpC.getReg();
 813
 814   if (Register::isVirtualRegister(RegA))
 815     MRI.constrainRegClass(RegA, RC);
 816   if (Register::isVirtualRegister(RegB))
 817     MRI.constrainRegClass(RegB, RC);
 818   if (Register::isVirtualRegister(RegX))
 819     MRI.constrainRegClass(RegX, RC);
 820   if (Register::isVirtualRegister(RegY))
 821     MRI.constrainRegClass(RegY, RC);
 822   if (Register::isVirtualRegister(RegC))
 823     MRI.constrainRegClass(RegC, RC);
 824
 825   // Create a new virtual register for the result of (X op Y) instead of
 826   // recycling RegB because the MachineCombiner's computation of the critical
 827   // path requires a new register definition rather than an existing one.
 828   Register NewVR = MRI.createVirtualRegister(RC);
 829   InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));
 830
 831   unsigned Opcode = Root.getOpcode();
 832   bool KillA = OpA.isKill();
 833   bool KillX = OpX.isKill();
 834   bool KillY = OpY.isKill();
 835
 836   // Create new instructions for insertion.
 837   MachineInstrBuilder MIB1 =
 838       BuildMI(*MF, Prev.getDebugLoc(), TII->get(Opcode), NewVR)
 839           .addReg(RegX, getKillRegState(KillX))
 840           .addReg(RegY, getKillRegState(KillY));
 841   MachineInstrBuilder MIB2 =
 842       BuildMI(*MF, Root.getDebugLoc(), TII->get(Opcode), RegC)
 843           .addReg(RegA, getKillRegState(KillA))
 844           .addReg(NewVR, getKillRegState(true));
 845
 846   setSpecialOperandAttr(Root, Prev, *MIB1, *MIB2);
 847
 848   // Record new instructions for insertion and old instructions for deletion.
 849   InsInstrs.push_back(MIB1);
 850   InsInstrs.push_back(MIB2);
 851   DelInstrs.push_back(&Prev);
 852   DelInstrs.push_back(&Root);
 853 }
 854
 855 void TargetInstrInfo::genAlternativeCodeSequence(
 856     MachineInstr &Root, MachineCombinerPattern Pattern,
 857     SmallVectorImpl<MachineInstr *> &InsInstrs,
 858     SmallVectorImpl<MachineInstr *> &DelInstrs,
 859     DenseMap<unsigned, unsigned> &InstIdxForVirtReg) const {
 860   MachineRegisterInfo &MRI = Root.getMF()->getRegInfo();
 861
 862   // Select the previous instruction in the sequence based on the input pattern.
 863   MachineInstr *Prev = nullptr;
 864   switch (Pattern) {
 865   case MachineCombinerPattern::REASSOC_AX_BY:
 866   case MachineCombinerPattern::REASSOC_XA_BY:
 867     Prev = MRI.getUniqueVRegDef(Root.getOperand(1).getReg());
 868     break;
 869   case MachineCombinerPattern::REASSOC_AX_YB:
 870   case MachineCombinerPattern::REASSOC_XA_YB:
 871     Prev = MRI.getUniqueVRegDef(Root.getOperand(2).getReg());
 872     break;
 873   default:
 874     break;
 875   }
 876
 877   assert(Prev && "Unknown pattern for machine combiner");
 878
 879   reassociateOps(Root, *Prev, Pattern, InsInstrs, DelInstrs, InstIdxForVirtReg);
 880 }
 881
 882 bool TargetInstrInfo::isReallyTriviallyReMaterializableGeneric(
 883     const MachineInstr &MI, AAResults *AA) const {
 884   const MachineFunction &MF = *MI.getMF();
 885   const MachineRegisterInfo &MRI = MF.getRegInfo();
 886
 887   // Remat clients assume operand 0 is the defined register.
 888   if (!MI.getNumOperands() || !MI.getOperand(0).isReg())
 889     return false;
 890   Register DefReg = MI.getOperand(0).getReg();
 891
 892   // A sub-register definition can only be rematerialized if the instruction
 893   // doesn't read the other parts of the register.  Otherwise it is really a
 894   // read-modify-write operation on the full virtual register which cannot be
 895   // moved safely.
 896   if (Register::isVirtualRegister(DefReg) && MI.getOperand(0).getSubReg() &&
 897       MI.readsVirtualRegister(DefReg))
 898     return false;
 899
 900   // A load from a fixed stack slot can be rematerialized. This may be
 901   // redundant with subsequent checks, but it's target-independent,
 902   // simple, and a common case.
 903   int FrameIdx = 0;
 904   if (isLoadFromStackSlot(MI, FrameIdx) &&
 905       MF.getFrameInfo().isImmutableObjectIndex(FrameIdx))
 906     return true;
 907
 908   // Avoid instructions obviously unsafe for remat.
 909   if (MI.isNotDuplicable() || MI.mayStore() || MI.mayRaiseFPException() ||
 910       MI.hasUnmodeledSideEffects())
 911     return false;
 912
 913   // Don't remat inline asm. We have no idea how expensive it is
 914   // even if it's side effect free.
 915   if (MI.isInlineAsm())
 916     return false;
 917
 918   // Avoid instructions which load from potentially varying memory.
 919   if (MI.mayLoad() && !MI.isDereferenceableInvariantLoad(AA))
 920     return false;
 921
 922   // If any of the registers accessed are non-constant, conservatively assume
 923   // the instruction is not rematerializable.
 924   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
 925     const MachineOperand &MO = MI.getOperand(i);
 926     if (!MO.isReg()) continue;
 927     Register Reg = MO.getReg();
 928     if (Reg == 0)
 929       continue;
 930
 931     // Check for a well-behaved physical register.
 932     if (Register::isPhysicalRegister(Reg)) {
 933       if (MO.isUse()) {
 934         // If the physreg has no defs anywhere, it's just an ambient register
 935         // and we can freely move its uses. Alternatively, if it's allocatable,
 936         // it could get allocated to something with a def during allocation.
 937         if (!MRI.isConstantPhysReg(Reg))
 938           return false;
 939       } else {
 940         // A physreg def. We can't remat it.
 941         return false;
 942       }
 943       continue;
 944     }
 945
 946     // Only allow one virtual-register def.  There may be multiple defs of the
 947     // same virtual register, though.
 948     if (MO.isDef() && Reg != DefReg)
 949       return false;
 950
 951     // Don't allow any virtual-register uses. Rematting an instruction with
 952     // virtual register uses would length the live ranges of the uses, which
 953     // is not necessarily a good idea, certainly not "trivial".
 954     if (MO.isUse())
 955       return false;
 956   }
 957
 958   // Everything checked out.
 959   return true;
 960 }
 961
 962 int TargetInstrInfo::getSPAdjust(const MachineInstr &MI) const {
 963   const MachineFunction *MF = MI.getMF();
 964   const TargetFrameLowering *TFI = MF->getSubtarget().getFrameLowering();
 965   bool StackGrowsDown =
 966     TFI->getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
 967
 968   unsigned FrameSetupOpcode = getCallFrameSetupOpcode();
 969   unsigned FrameDestroyOpcode = getCallFrameDestroyOpcode();
 970
 971   if (!isFrameInstr(MI))
 972     return 0;
 973
 974   int SPAdj = TFI->alignSPAdjust(getFrameSize(MI));
 975
 976   if ((!StackGrowsDown && MI.getOpcode() == FrameSetupOpcode) ||
 977       (StackGrowsDown && MI.getOpcode() == FrameDestroyOpcode))
 978     SPAdj = -SPAdj;
 979
 980   return SPAdj;
 981 }
 982
 983 /// isSchedulingBoundary - Test if the given instruction should be
 984 /// considered a scheduling boundary. This primarily includes labels
 985 /// and terminators.
 986 bool TargetInstrInfo::isSchedulingBoundary(const MachineInstr &MI,
 987                                            const MachineBasicBlock *MBB,
 988                                            const MachineFunction &MF) const {
 989   // Terminators and labels can't be scheduled around.
 990   if (MI.isTerminator() || MI.isPosition())
 991     return true;
 992
 993   // Don't attempt to schedule around any instruction that defines
 994   // a stack-oriented pointer, as it's unlikely to be profitable. This
 995   // saves compile time, because it doesn't require every single
 996   // stack slot reference to depend on the instruction that does the
 997   // modification.
 998   const TargetLowering &TLI = *MF.getSubtarget().getTargetLowering();
 999   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
1000   return MI.modifiesRegister(TLI.getStackPointerRegisterToSaveRestore(), TRI);
1001 }
1002
1003 // Provide a global flag for disabling the PreRA hazard recognizer that targets
1004 // may choose to honor.
1005 bool TargetInstrInfo::usePreRAHazardRecognizer() const {
1006   return !DisableHazardRecognizer;
1007 }
1008
1009 // Default implementation of CreateTargetRAHazardRecognizer.
1010 ScheduleHazardRecognizer *TargetInstrInfo::
1011 CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
1012                              const ScheduleDAG *DAG) const {
1013   // Dummy hazard recognizer allows all instructions to issue.
1014   return new ScheduleHazardRecognizer();
1015 }
1016
1017 // Default implementation of CreateTargetMIHazardRecognizer.
1018 ScheduleHazardRecognizer *TargetInstrInfo::
1019 CreateTargetMIHazardRecognizer(const InstrItineraryData *II,
1020                                const ScheduleDAG *DAG) const {
1021   return (ScheduleHazardRecognizer *)
1022     new ScoreboardHazardRecognizer(II, DAG, "machine-scheduler");
1023 }
1024
1025 // Default implementation of CreateTargetPostRAHazardRecognizer.
1026 ScheduleHazardRecognizer *TargetInstrInfo::
1027 CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
1028                                    const ScheduleDAG *DAG) const {
1029   return (ScheduleHazardRecognizer *)
1030     new ScoreboardHazardRecognizer(II, DAG, "post-RA-sched");
1031 }
1032
1033 //===----------------------------------------------------------------------===//
1034 //  SelectionDAG latency interface.
1035 //===----------------------------------------------------------------------===//
1036
1037 int
1038 TargetInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
1039                                    SDNode *DefNode, unsigned DefIdx,
1040                                    SDNode *UseNode, unsigned UseIdx) const {
1041   if (!ItinData || ItinData->isEmpty())
1042     return -1;
1043
1044   if (!DefNode->isMachineOpcode())
1045     return -1;
1046
1047   unsigned DefClass = get(DefNode->getMachineOpcode()).getSchedClass();
1048   if (!UseNode->isMachineOpcode())
1049     return ItinData->getOperandCycle(DefClass, DefIdx);
1050   unsigned UseClass = get(UseNode->getMachineOpcode()).getSchedClass();
1051   return ItinData->getOperandLatency(DefClass, DefIdx, UseClass, UseIdx);
1052 }
1053
1054 int TargetInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
1055                                      SDNode *N) const {
1056   if (!ItinData || ItinData->isEmpty())
1057     return 1;
1058
1059   if (!N->isMachineOpcode())
1060     return 1;
1061
1062   return ItinData->getStageLatency(get(N->getMachineOpcode()).getSchedClass());
1063 }
1064
1065 //===----------------------------------------------------------------------===//
1066 //  MachineInstr latency interface.
1067 //===----------------------------------------------------------------------===//
1068
1069 unsigned TargetInstrInfo::getNumMicroOps(const InstrItineraryData *ItinData,
1070                                          const MachineInstr &MI) const {
1071   if (!ItinData || ItinData->isEmpty())
1072     return 1;
1073
1074   unsigned Class = MI.getDesc().getSchedClass();
1075   int UOps = ItinData->Itineraries[Class].NumMicroOps;
1076   if (UOps >= 0)
1077     return UOps;
1078
1079   // The # of u-ops is dynamically determined. The specific target should
1080   // override this function to return the right number.
1081   return 1;
1082 }
1083
1084 /// Return the default expected latency for a def based on it's opcode.
1085 unsigned TargetInstrInfo::defaultDefLatency(const MCSchedModel &SchedModel,
1086                                             const MachineInstr &DefMI) const {
1087   if (DefMI.isTransient())
1088     return 0;
1089   if (DefMI.mayLoad())
1090     return SchedModel.LoadLatency;
1091   if (isHighLatencyDef(DefMI.getOpcode()))
1092     return SchedModel.HighLatency;
1093   return 1;
1094 }
1095
1096 unsigned TargetInstrInfo::getPredicationCost(const MachineInstr &) const {
1097   return 0;
1098 }
1099
1100 unsigned TargetInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
1101                                           const MachineInstr &MI,
1102                                           unsigned *PredCost) const {
1103   // Default to one cycle for no itinerary. However, an "empty" itinerary may
1104   // still have a MinLatency property, which getStageLatency checks.
1105   if (!ItinData)
1106     return MI.mayLoad() ? 2 : 1;
1107
1108   return ItinData->getStageLatency(MI.getDesc().getSchedClass());
1109 }
1110
1111 bool TargetInstrInfo::hasLowDefLatency(const TargetSchedModel &SchedModel,
1112                                        const MachineInstr &DefMI,
1113                                        unsigned DefIdx) const {
1114   const InstrItineraryData *ItinData = SchedModel.getInstrItineraries();
1115   if (!ItinData || ItinData->isEmpty())
1116     return false;
1117
1118   unsigned DefClass = DefMI.getDesc().getSchedClass();
1119   int DefCycle = ItinData->getOperandCycle(DefClass, DefIdx);
1120   return (DefCycle != -1 && DefCycle <= 1);
1121 }
1122
1123 Optional<ParamLoadedValue>
1124 TargetInstrInfo::describeLoadedValue(const MachineInstr &MI) const {
1125   const MachineFunction *MF = MI.getMF();
1126   const MachineOperand *Op = nullptr;
1127   DIExpression *Expr = DIExpression::get(MF->getFunction().getContext(), {});;
1128   const MachineOperand *SrcRegOp, *DestRegOp;
1129
1130   if (isCopyInstr(MI, SrcRegOp, DestRegOp)) {
1131     Op = SrcRegOp;
1132     return ParamLoadedValue(*Op, Expr);
1133   } else if (MI.isMoveImmediate()) {
1134     Op = &MI.getOperand(1);
1135     return ParamLoadedValue(*Op, Expr);
1136   }
1137
1138   return None;
1139 }
1140
1141 /// Both DefMI and UseMI must be valid.  By default, call directly to the
1142 /// itinerary. This may be overriden by the target.
1143 int TargetInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
1144                                        const MachineInstr &DefMI,
1145                                        unsigned DefIdx,
1146                                        const MachineInstr &UseMI,
1147                                        unsigned UseIdx) const {
1148   unsigned DefClass = DefMI.getDesc().getSchedClass();
1149   unsigned UseClass = UseMI.getDesc().getSchedClass();
1150   return ItinData->getOperandLatency(DefClass, DefIdx, UseClass, UseIdx);
1151 }
1152
1153 /// If we can determine the operand latency from the def only, without itinerary
1154 /// lookup, do so. Otherwise return -1.
1155 int TargetInstrInfo::computeDefOperandLatency(
1156     const InstrItineraryData *ItinData, const MachineInstr &DefMI) const {
1157
1158   // Let the target hook getInstrLatency handle missing itineraries.
1159   if (!ItinData)
1160     return getInstrLatency(ItinData, DefMI);
1161
1162   if(ItinData->isEmpty())
1163     return defaultDefLatency(ItinData->SchedModel, DefMI);
1164
1165   // ...operand lookup required
1166   return -1;
1167 }
1168
1169 bool TargetInstrInfo::getRegSequenceInputs(
1170     const MachineInstr &MI, unsigned DefIdx,
1171     SmallVectorImpl<RegSubRegPairAndIdx> &InputRegs) const {
1172   assert((MI.isRegSequence() ||
1173           MI.isRegSequenceLike()) && "Instruction do not have the proper type");
1174
1175   if (!MI.isRegSequence())
1176     return getRegSequenceLikeInputs(MI, DefIdx, InputRegs);
1177
1178   // We are looking at:
1179   // Def = REG_SEQUENCE v0, sub0, v1, sub1, ...
1180   assert(DefIdx == 0 && "REG_SEQUENCE only has one def");
1181   for (unsigned OpIdx = 1, EndOpIdx = MI.getNumOperands(); OpIdx != EndOpIdx;
1182        OpIdx += 2) {
1183     const MachineOperand &MOReg = MI.getOperand(OpIdx);
1184     if (MOReg.isUndef())
1185       continue;
1186     const MachineOperand &MOSubIdx = MI.getOperand(OpIdx + 1);
1187     assert(MOSubIdx.isImm() &&
1188            "One of the subindex of the reg_sequence is not an immediate");
1189     // Record Reg:SubReg, SubIdx.
1190     InputRegs.push_back(RegSubRegPairAndIdx(MOReg.getReg(), MOReg.getSubReg(),
1191                                             (unsigned)MOSubIdx.getImm()));
1192   }
1193   return true;
1194 }
1195
1196 bool TargetInstrInfo::getExtractSubregInputs(
1197     const MachineInstr &MI, unsigned DefIdx,
1198     RegSubRegPairAndIdx &InputReg) const {
1199   assert((MI.isExtractSubreg() ||
1200       MI.isExtractSubregLike()) && "Instruction do not have the proper type");
1201
1202   if (!MI.isExtractSubreg())
1203     return getExtractSubregLikeInputs(MI, DefIdx, InputReg);
1204
1205   // We are looking at:
1206   // Def = EXTRACT_SUBREG v0.sub1, sub0.
1207   assert(DefIdx == 0 && "EXTRACT_SUBREG only has one def");
1208   const MachineOperand &MOReg = MI.getOperand(1);
1209   if (MOReg.isUndef())
1210     return false;
1211   const MachineOperand &MOSubIdx = MI.getOperand(2);
1212   assert(MOSubIdx.isImm() &&
1213          "The subindex of the extract_subreg is not an immediate");
1214
1215   InputReg.Reg = MOReg.getReg();
1216   InputReg.SubReg = MOReg.getSubReg();
1217   InputReg.SubIdx = (unsigned)MOSubIdx.getImm();
1218   return true;
1219 }
1220
1221 bool TargetInstrInfo::getInsertSubregInputs(
1222     const MachineInstr &MI, unsigned DefIdx,
1223     RegSubRegPair &BaseReg, RegSubRegPairAndIdx &InsertedReg) const {
1224   assert((MI.isInsertSubreg() ||
1225       MI.isInsertSubregLike()) && "Instruction do not have the proper type");
1226
1227   if (!MI.isInsertSubreg())
1228     return getInsertSubregLikeInputs(MI, DefIdx, BaseReg, InsertedReg);
1229
1230   // We are looking at:
1231   // Def = INSERT_SEQUENCE v0, v1, sub0.
1232   assert(DefIdx == 0 && "INSERT_SUBREG only has one def");
1233   const MachineOperand &MOBaseReg = MI.getOperand(1);
1234   const MachineOperand &MOInsertedReg = MI.getOperand(2);
1235   if (MOInsertedReg.isUndef())
1236     return false;
1237   const MachineOperand &MOSubIdx = MI.getOperand(3);
1238   assert(MOSubIdx.isImm() &&
1239          "One of the subindex of the reg_sequence is not an immediate");
1240   BaseReg.Reg = MOBaseReg.getReg();
1241   BaseReg.SubReg = MOBaseReg.getSubReg();
1242
1243   InsertedReg.Reg = MOInsertedReg.getReg();
1244   InsertedReg.SubReg = MOInsertedReg.getSubReg();
1245   InsertedReg.SubIdx = (unsigned)MOSubIdx.getImm();
1246   return true;
1247 }
1248
1249 TargetInstrInfo::PipelinerLoopInfo::~PipelinerLoopInfo() {}