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1//===- HexagonConstExtenders.cpp ------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "HexagonInstrInfo.h"10#include "HexagonRegisterInfo.h"11#include "HexagonSubtarget.h"12#include "llvm/ADT/SetVector.h"13#include "llvm/ADT/SmallVector.h"14#include "llvm/CodeGen/MachineDominators.h"15#include "llvm/CodeGen/MachineFunctionPass.h"16#include "llvm/CodeGen/MachineInstrBuilder.h"17#include "llvm/CodeGen/MachineRegisterInfo.h"18#include "llvm/CodeGen/Register.h"19#include "llvm/InitializePasses.h"20#include "llvm/Pass.h"21#include "llvm/Support/CommandLine.h"22#include "llvm/Support/raw_ostream.h"23#include <map>24#include <set>25#include <utility>26#include <vector>27 28#define DEBUG_TYPE "hexagon-cext-opt"29 30using namespace llvm;31 32static cl::opt<unsigned> CountThreshold(33    "hexagon-cext-threshold", cl::init(3), cl::Hidden,34    cl::desc("Minimum number of extenders to trigger replacement"));35 36static cl::opt<unsigned>37    ReplaceLimit("hexagon-cext-limit", cl::init(0), cl::Hidden,38                 cl::desc("Maximum number of replacements"));39 40static int32_t adjustUp(int32_t V, uint8_t A, uint8_t O) {41  assert(isPowerOf2_32(A));42  int32_t U = (V & -A) + O;43  return U >= V ? U : U+A;44}45 46static int32_t adjustDown(int32_t V, uint8_t A, uint8_t O) {47  assert(isPowerOf2_32(A));48  int32_t U = (V & -A) + O;49  return U <= V ? U : U-A;50}51 52namespace {53  struct OffsetRange {54    // The range of values between Min and Max that are of form Align*N+Offset,55    // for some integer N. Min and Max are required to be of that form as well,56    // except in the case of an empty range.57    int32_t Min = INT_MIN, Max = INT_MAX;58    uint8_t Align = 1;59    uint8_t Offset = 0;60 61    OffsetRange() = default;62    OffsetRange(int32_t L, int32_t H, uint8_t A, uint8_t O = 0)63      : Min(L), Max(H), Align(A), Offset(O) {}64    OffsetRange &intersect(OffsetRange A) {65      if (Align < A.Align)66        std::swap(*this, A);67 68      // Align >= A.Align.69      if (Offset >= A.Offset && (Offset - A.Offset) % A.Align == 0) {70        Min = adjustUp(std::max(Min, A.Min), Align, Offset);71        Max = adjustDown(std::min(Max, A.Max), Align, Offset);72      } else {73        // Make an empty range.74        Min = 0;75        Max = -1;76      }77      // Canonicalize empty ranges.78      if (Min > Max)79        std::tie(Min, Max, Align) = std::make_tuple(0, -1, 1);80      return *this;81    }82    OffsetRange &shift(int32_t S) {83      Min += S;84      Max += S;85      Offset = (Offset+S) % Align;86      return *this;87    }88    OffsetRange &extendBy(int32_t D) {89      // If D < 0, extend Min, otherwise extend Max.90      assert(D % Align == 0);91      if (D < 0)92        Min = (INT_MIN-D < Min) ? Min+D : INT_MIN;93      else94        Max = (INT_MAX-D > Max) ? Max+D : INT_MAX;95      return *this;96    }97    bool empty() const {98      return Min > Max;99    }100    bool contains(int32_t V) const {101      return Min <= V && V <= Max && (V-Offset) % Align == 0;102    }103    bool operator==(const OffsetRange &R) const {104      return Min == R.Min && Max == R.Max && Align == R.Align;105    }106    bool operator!=(const OffsetRange &R) const {107      return !operator==(R);108    }109    bool operator<(const OffsetRange &R) const {110      return std::tie(Min, Max, Align) < std::tie(R.Min, R.Max, R.Align);111    }112    static OffsetRange zero() { return {0, 0, 1}; }113  };114 115  struct RangeTree {116    struct Node {117      Node(const OffsetRange &R) : MaxEnd(R.Max), Range(R) {}118      unsigned Height = 1;119      unsigned Count = 1;120      int32_t MaxEnd;121      const OffsetRange &Range;122      Node *Left = nullptr, *Right = nullptr;123    };124 125    Node *Root = nullptr;126 127    void add(const OffsetRange &R) {128      Root = add(Root, R);129    }130    void erase(const Node *N) {131      Root = remove(Root, N);132      delete N;133    }134    void order(SmallVectorImpl<Node*> &Seq) const {135      order(Root, Seq);136    }137    SmallVector<Node*,8> nodesWith(int32_t P, bool CheckAlign = true) {138      SmallVector<Node*,8> Nodes;139      nodesWith(Root, P, CheckAlign, Nodes);140      return Nodes;141    }142    void dump() const;143    ~RangeTree() {144      SmallVector<Node*,8> Nodes;145      order(Nodes);146      for (Node *N : Nodes)147        delete N;148    }149 150  private:151    void dump(const Node *N) const;152    void order(Node *N, SmallVectorImpl<Node*> &Seq) const;153    void nodesWith(Node *N, int32_t P, bool CheckA,154                   SmallVectorImpl<Node*> &Seq) const;155 156    Node *add(Node *N, const OffsetRange &R);157    Node *remove(Node *N, const Node *D);158    Node *rotateLeft(Node *Lower, Node *Higher);159    Node *rotateRight(Node *Lower, Node *Higher);160    unsigned height(Node *N) {161      return N != nullptr ? N->Height : 0;162    }163    Node *update(Node *N) {164      assert(N != nullptr);165      N->Height = 1 + std::max(height(N->Left), height(N->Right));166      if (N->Left)167        N->MaxEnd = std::max(N->MaxEnd, N->Left->MaxEnd);168      if (N->Right)169        N->MaxEnd = std::max(N->MaxEnd, N->Right->MaxEnd);170      return N;171    }172    Node *rebalance(Node *N) {173      assert(N != nullptr);174      int32_t Balance = height(N->Right) - height(N->Left);175      if (Balance < -1)176        return rotateRight(N->Left, N);177      if (Balance > 1)178        return rotateLeft(N->Right, N);179      return N;180    }181  };182 183  struct Loc {184    MachineBasicBlock *Block = nullptr;185    MachineBasicBlock::iterator At;186 187    Loc(MachineBasicBlock *B, MachineBasicBlock::iterator It)188      : Block(B), At(It) {189      if (B->end() == It) {190        Pos = -1;191      } else {192        assert(It->getParent() == B);193        Pos = std::distance(B->begin(), It);194      }195    }196    bool operator<(Loc A) const {197      if (Block != A.Block)198        return Block->getNumber() < A.Block->getNumber();199      if (A.Pos == -1)200        return Pos != A.Pos;201      return Pos != -1 && Pos < A.Pos;202    }203  private:204    int Pos = 0;205  };206 207  struct HexagonConstExtenders : public MachineFunctionPass {208    static char ID;209    HexagonConstExtenders() : MachineFunctionPass(ID) {}210 211    void getAnalysisUsage(AnalysisUsage &AU) const override {212      AU.addRequired<MachineDominatorTreeWrapperPass>();213      AU.addPreserved<MachineDominatorTreeWrapperPass>();214      MachineFunctionPass::getAnalysisUsage(AU);215    }216 217    StringRef getPassName() const override {218      return "Hexagon constant-extender optimization";219    }220    bool runOnMachineFunction(MachineFunction &MF) override;221 222  private:223    struct Register {224      Register() = default;225      Register(llvm::Register R, unsigned S) : Reg(R), Sub(S) {}226      Register(const MachineOperand &Op)227        : Reg(Op.getReg()), Sub(Op.getSubReg()) {}228      Register &operator=(const MachineOperand &Op) {229        if (Op.isReg()) {230          Reg = Op.getReg();231          Sub = Op.getSubReg();232        } else if (Op.isFI()) {233          Reg = llvm::Register::index2StackSlot(Op.getIndex());234        }235        return *this;236      }237      bool isVReg() const {238        return Reg != 0 && !Reg.isStack() && Reg.isVirtual();239      }240      bool isSlot() const { return Reg != 0 && Reg.isStack(); }241      operator MachineOperand() const {242        if (isVReg())243          return MachineOperand::CreateReg(Reg, /*Def*/false, /*Imp*/false,244                          /*Kill*/false, /*Dead*/false, /*Undef*/false,245                          /*EarlyClobber*/false, Sub);246        if (Reg.isStack()) {247          int FI = Reg.stackSlotIndex();248          return MachineOperand::CreateFI(FI);249        }250        llvm_unreachable("Cannot create MachineOperand");251      }252      bool operator==(Register R) const { return Reg == R.Reg && Sub == R.Sub; }253      bool operator!=(Register R) const { return !operator==(R); }254      bool operator<(Register R) const {255        // For std::map.256        return std::tie(Reg, Sub) < std::tie(R.Reg, R.Sub);257      }258      llvm::Register Reg;259      unsigned Sub = 0;260    };261 262    struct ExtExpr {263      // A subexpression in which the extender is used. In general, this264      // represents an expression where adding D to the extender will be265      // equivalent to adding D to the expression as a whole. In other266      // words, expr(add(##V,D) = add(expr(##V),D).267 268      // The original motivation for this are the io/ur addressing modes,269      // where the offset is extended. Consider the io example:270      // In memw(Rs+##V), the ##V could be replaced by a register Rt to271      // form the rr mode: memw(Rt+Rs<<0). In such case, however, the272      // register Rt must have exactly the value of ##V. If there was273      // another instruction memw(Rs+##V+4), it would need a different Rt.274      // Now, if Rt was initialized as "##V+Rs<<0", both of these275      // instructions could use the same Rt, just with different offsets.276      // Here it's clear that "initializer+4" should be the same as if277      // the offset 4 was added to the ##V in the initializer.278 279      // The only kinds of expressions that support the requirement of280      // commuting with addition are addition and subtraction from ##V.281      // Include shifting the Rs to account for the ur addressing mode:282      //   ##Val + Rs << S283      //   ##Val - Rs284      Register Rs;285      unsigned S = 0;286      bool Neg = false;287 288      ExtExpr() = default;289      ExtExpr(Register RS, bool NG, unsigned SH) : Rs(RS), S(SH), Neg(NG) {}290      // Expression is trivial if it does not modify the extender.291      bool trivial() const {292        return Rs.Reg == 0;293      }294      bool operator==(const ExtExpr &Ex) const {295        return Rs == Ex.Rs && S == Ex.S && Neg == Ex.Neg;296      }297      bool operator!=(const ExtExpr &Ex) const {298        return !operator==(Ex);299      }300      bool operator<(const ExtExpr &Ex) const {301        return std::tie(Rs, S, Neg) < std::tie(Ex.Rs, Ex.S, Ex.Neg);302      }303    };304 305    struct ExtDesc {306      MachineInstr *UseMI = nullptr;307      unsigned OpNum = -1u;308      // The subexpression in which the extender is used (e.g. address309      // computation).310      ExtExpr Expr;311      // Optional register that is assigned the value of Expr.312      Register Rd;313      // Def means that the output of the instruction may differ from the314      // original by a constant c, and that the difference can be corrected315      // by adding/subtracting c in all users of the defined register.316      bool IsDef = false;317 318      MachineOperand &getOp() {319        return UseMI->getOperand(OpNum);320      }321      const MachineOperand &getOp() const {322        return UseMI->getOperand(OpNum);323      }324    };325 326    struct ExtRoot {327      union {328        const ConstantFP *CFP;  // MO_FPImmediate329        const char *SymbolName; // MO_ExternalSymbol330        const GlobalValue *GV;  // MO_GlobalAddress331        const BlockAddress *BA; // MO_BlockAddress332        int64_t ImmVal;         // MO_Immediate, MO_TargetIndex,333                                // and MO_ConstantPoolIndex334      } V;335      unsigned Kind;            // Same as in MachineOperand.336      unsigned char TF;         // TargetFlags.337 338      ExtRoot(const MachineOperand &Op);339      bool operator==(const ExtRoot &ER) const {340        return Kind == ER.Kind && V.ImmVal == ER.V.ImmVal;341      }342      bool operator!=(const ExtRoot &ER) const {343        return !operator==(ER);344      }345      bool operator<(const ExtRoot &ER) const;346    };347 348    struct ExtValue : public ExtRoot {349      int32_t Offset;350 351      ExtValue(const MachineOperand &Op);352      ExtValue(const ExtDesc &ED) : ExtValue(ED.getOp()) {}353      ExtValue(const ExtRoot &ER, int32_t Off) : ExtRoot(ER), Offset(Off) {}354      bool operator<(const ExtValue &EV) const;355      bool operator==(const ExtValue &EV) const {356        return ExtRoot(*this) == ExtRoot(EV) && Offset == EV.Offset;357      }358      bool operator!=(const ExtValue &EV) const {359        return !operator==(EV);360      }361      explicit operator MachineOperand() const;362    };363 364    using IndexList = SetVector<unsigned>;365    using ExtenderInit = std::pair<ExtValue, ExtExpr>;366    using AssignmentMap = std::map<ExtenderInit, IndexList>;367    using LocDefList = std::vector<std::pair<Loc, IndexList>>;368 369    const HexagonSubtarget *HST = nullptr;370    const HexagonInstrInfo *HII = nullptr;371    const HexagonRegisterInfo *HRI = nullptr;372    MachineDominatorTree *MDT = nullptr;373    MachineRegisterInfo *MRI = nullptr;374    std::vector<ExtDesc> Extenders;375    std::vector<unsigned> NewRegs;376 377    bool isStoreImmediate(unsigned Opc) const;378    bool isRegOffOpcode(unsigned ExtOpc) const ;379    unsigned getRegOffOpcode(unsigned ExtOpc) const;380    unsigned getDirectRegReplacement(unsigned ExtOpc) const;381    OffsetRange getOffsetRange(Register R, const MachineInstr &MI) const;382    OffsetRange getOffsetRange(const ExtDesc &ED) const;383    OffsetRange getOffsetRange(Register Rd) const;384 385    void recordExtender(MachineInstr &MI, unsigned OpNum);386    void collectInstr(MachineInstr &MI);387    void collect(MachineFunction &MF);388    void assignInits(const ExtRoot &ER, unsigned Begin, unsigned End,389                     AssignmentMap &IMap);390    void calculatePlacement(const ExtenderInit &ExtI, const IndexList &Refs,391                            LocDefList &Defs);392    Register insertInitializer(Loc DefL, const ExtenderInit &ExtI);393    bool replaceInstrExact(const ExtDesc &ED, Register ExtR);394    bool replaceInstrExpr(const ExtDesc &ED, const ExtenderInit &ExtI,395                          Register ExtR, int32_t &Diff);396    bool replaceInstr(unsigned Idx, Register ExtR, const ExtenderInit &ExtI);397    bool replaceExtenders(const AssignmentMap &IMap);398 399    unsigned getOperandIndex(const MachineInstr &MI,400                             const MachineOperand &Op) const;401    const MachineOperand &getPredicateOp(const MachineInstr &MI) const;402    const MachineOperand &getLoadResultOp(const MachineInstr &MI) const;403    const MachineOperand &getStoredValueOp(const MachineInstr &MI) const;404 405    friend struct PrintRegister;406    friend struct PrintExpr;407    friend struct PrintInit;408    friend struct PrintIMap;409    friend raw_ostream &operator<< (raw_ostream &OS,410                                    const struct PrintRegister &P);411    friend raw_ostream &operator<< (raw_ostream &OS, const struct PrintExpr &P);412    friend raw_ostream &operator<< (raw_ostream &OS, const struct PrintInit &P);413    friend raw_ostream &operator<< (raw_ostream &OS, const ExtDesc &ED);414    friend raw_ostream &operator<< (raw_ostream &OS, const ExtRoot &ER);415    friend raw_ostream &operator<< (raw_ostream &OS, const ExtValue &EV);416    friend raw_ostream &operator<< (raw_ostream &OS, const OffsetRange &OR);417    friend raw_ostream &operator<< (raw_ostream &OS, const struct PrintIMap &P);418  };419 420  using HCE = HexagonConstExtenders;421 422  [[maybe_unused]]423  raw_ostream &operator<<(raw_ostream &OS, const OffsetRange &OR) {424    if (OR.Min > OR.Max)425      OS << '!';426    OS << '[' << OR.Min << ',' << OR.Max << "]a" << unsigned(OR.Align)427       << '+' << unsigned(OR.Offset);428    return OS;429  }430 431  struct PrintRegister {432    PrintRegister(HCE::Register R, const HexagonRegisterInfo &I)433      : Rs(R), HRI(I) {}434    HCE::Register Rs;435    const HexagonRegisterInfo &HRI;436  };437 438  [[maybe_unused]]439  raw_ostream &operator<<(raw_ostream &OS, const PrintRegister &P) {440    if (P.Rs.Reg != 0)441      OS << printReg(P.Rs.Reg, &P.HRI, P.Rs.Sub);442    else443      OS << "noreg";444    return OS;445  }446 447  struct PrintExpr {448    PrintExpr(const HCE::ExtExpr &E, const HexagonRegisterInfo &I)449      : Ex(E), HRI(I) {}450    const HCE::ExtExpr &Ex;451    const HexagonRegisterInfo &HRI;452  };453 454  [[maybe_unused]]455  raw_ostream &operator<<(raw_ostream &OS, const PrintExpr &P) {456    OS << "## " << (P.Ex.Neg ? "- " : "+ ");457    if (P.Ex.Rs.Reg != 0)458      OS << printReg(P.Ex.Rs.Reg, &P.HRI, P.Ex.Rs.Sub);459    else460      OS << "__";461    OS << " << " << P.Ex.S;462    return OS;463  }464 465  struct PrintInit {466    PrintInit(const HCE::ExtenderInit &EI, const HexagonRegisterInfo &I)467      : ExtI(EI), HRI(I) {}468    const HCE::ExtenderInit &ExtI;469    const HexagonRegisterInfo &HRI;470  };471 472  [[maybe_unused]]473  raw_ostream &operator<<(raw_ostream &OS, const PrintInit &P) {474    OS << '[' << P.ExtI.first << ", "475       << PrintExpr(P.ExtI.second, P.HRI) << ']';476    return OS;477  }478 479  [[maybe_unused]]480  raw_ostream &operator<<(raw_ostream &OS, const HCE::ExtDesc &ED) {481    assert(ED.OpNum != -1u);482    const MachineBasicBlock &MBB = *ED.getOp().getParent()->getParent();483    const MachineFunction &MF = *MBB.getParent();484    const auto &HRI = *MF.getSubtarget<HexagonSubtarget>().getRegisterInfo();485    OS << "bb#" << MBB.getNumber() << ": ";486    if (ED.Rd.Reg != 0)487      OS << printReg(ED.Rd.Reg, &HRI, ED.Rd.Sub);488    else489      OS << "__";490    OS << " = " << PrintExpr(ED.Expr, HRI);491    if (ED.IsDef)492      OS << ", def";493    return OS;494  }495 496  [[maybe_unused]]497  raw_ostream &operator<<(raw_ostream &OS, const HCE::ExtRoot &ER) {498    switch (ER.Kind) {499      case MachineOperand::MO_Immediate:500        OS << "imm:" << ER.V.ImmVal;501        break;502      case MachineOperand::MO_FPImmediate:503        OS << "fpi:" << *ER.V.CFP;504        break;505      case MachineOperand::MO_ExternalSymbol:506        OS << "sym:" << *ER.V.SymbolName;507        break;508      case MachineOperand::MO_GlobalAddress:509        OS << "gad:" << ER.V.GV->getName();510        break;511      case MachineOperand::MO_BlockAddress:512        OS << "blk:" << *ER.V.BA;513        break;514      case MachineOperand::MO_TargetIndex:515        OS << "tgi:" << ER.V.ImmVal;516        break;517      case MachineOperand::MO_ConstantPoolIndex:518        OS << "cpi:" << ER.V.ImmVal;519        break;520      case MachineOperand::MO_JumpTableIndex:521        OS << "jti:" << ER.V.ImmVal;522        break;523      default:524        OS << "???:" << ER.V.ImmVal;525        break;526    }527    return OS;528  }529 530  [[maybe_unused]]531  raw_ostream &operator<<(raw_ostream &OS, const HCE::ExtValue &EV) {532    OS << HCE::ExtRoot(EV) << "  off:" << EV.Offset;533    return OS;534  }535 536  struct PrintIMap {537    PrintIMap(const HCE::AssignmentMap &M, const HexagonRegisterInfo &I)538      : IMap(M), HRI(I) {}539    const HCE::AssignmentMap &IMap;540    const HexagonRegisterInfo &HRI;541  };542 543  [[maybe_unused]]544  raw_ostream &operator<<(raw_ostream &OS, const PrintIMap &P) {545    OS << "{\n";546    for (const std::pair<const HCE::ExtenderInit, HCE::IndexList> &Q : P.IMap) {547      OS << "  " << PrintInit(Q.first, P.HRI) << " -> {";548      for (unsigned I : Q.second)549        OS << ' ' << I;550      OS << " }\n";551    }552    OS << "}\n";553    return OS;554  }555}556 557INITIALIZE_PASS_BEGIN(HexagonConstExtenders, "hexagon-cext-opt",558      "Hexagon constant-extender optimization", false, false)559INITIALIZE_PASS_DEPENDENCY(MachineDominatorTreeWrapperPass)560INITIALIZE_PASS_END(HexagonConstExtenders, "hexagon-cext-opt",561      "Hexagon constant-extender optimization", false, false)562 563static unsigned ReplaceCounter = 0;564 565char HCE::ID = 0;566 567#ifndef NDEBUG568LLVM_DUMP_METHOD void RangeTree::dump() const {569  dbgs() << "Root: " << Root << '\n';570  if (Root)571    dump(Root);572}573 574LLVM_DUMP_METHOD void RangeTree::dump(const Node *N) const {575  dbgs() << "Node: " << N << '\n';576  dbgs() << "  Height: " << N->Height << '\n';577  dbgs() << "  Count: " << N->Count << '\n';578  dbgs() << "  MaxEnd: " << N->MaxEnd << '\n';579  dbgs() << "  Range: " << N->Range << '\n';580  dbgs() << "  Left: " << N->Left << '\n';581  dbgs() << "  Right: " << N->Right << "\n\n";582 583  if (N->Left)584    dump(N->Left);585  if (N->Right)586    dump(N->Right);587}588#endif589 590void RangeTree::order(Node *N, SmallVectorImpl<Node*> &Seq) const {591  if (N == nullptr)592    return;593  order(N->Left, Seq);594  Seq.push_back(N);595  order(N->Right, Seq);596}597 598void RangeTree::nodesWith(Node *N, int32_t P, bool CheckA,599      SmallVectorImpl<Node*> &Seq) const {600  if (N == nullptr || N->MaxEnd < P)601    return;602  nodesWith(N->Left, P, CheckA, Seq);603  if (N->Range.Min <= P) {604    if ((CheckA && N->Range.contains(P)) || (!CheckA && P <= N->Range.Max))605      Seq.push_back(N);606    nodesWith(N->Right, P, CheckA, Seq);607  }608}609 610RangeTree::Node *RangeTree::add(Node *N, const OffsetRange &R) {611  if (N == nullptr)612    return new Node(R);613 614  if (N->Range == R) {615    N->Count++;616    return N;617  }618 619  if (R < N->Range)620    N->Left = add(N->Left, R);621  else622    N->Right = add(N->Right, R);623  return rebalance(update(N));624}625 626RangeTree::Node *RangeTree::remove(Node *N, const Node *D) {627  assert(N != nullptr);628 629  if (N != D) {630    assert(N->Range != D->Range && "N and D should not be equal");631    if (D->Range < N->Range)632      N->Left = remove(N->Left, D);633    else634      N->Right = remove(N->Right, D);635    return rebalance(update(N));636  }637 638  // We got to the node we need to remove. If any of its children are639  // missing, simply replace it with the other child.640  if (N->Left == nullptr || N->Right == nullptr)641    return (N->Left == nullptr) ? N->Right : N->Left;642 643  // Find the rightmost child of N->Left, remove it and plug it in place644  // of N.645  Node *M = N->Left;646  while (M->Right)647    M = M->Right;648  M->Left = remove(N->Left, M);649  M->Right = N->Right;650  return rebalance(update(M));651}652 653RangeTree::Node *RangeTree::rotateLeft(Node *Lower, Node *Higher) {654  assert(Higher->Right == Lower);655  // The Lower node is on the right from Higher. Make sure that Lower's656  // balance is greater to the right. Otherwise the rotation will create657  // an unbalanced tree again.658  if (height(Lower->Left) > height(Lower->Right))659    Lower = rotateRight(Lower->Left, Lower);660  assert(height(Lower->Left) <= height(Lower->Right));661  Higher->Right = Lower->Left;662  update(Higher);663  Lower->Left = Higher;664  update(Lower);665  return Lower;666}667 668RangeTree::Node *RangeTree::rotateRight(Node *Lower, Node *Higher) {669  assert(Higher->Left == Lower);670  // The Lower node is on the left from Higher. Make sure that Lower's671  // balance is greater to the left. Otherwise the rotation will create672  // an unbalanced tree again.673  if (height(Lower->Left) < height(Lower->Right))674    Lower = rotateLeft(Lower->Right, Lower);675  assert(height(Lower->Left) >= height(Lower->Right));676  Higher->Left = Lower->Right;677  update(Higher);678  Lower->Right = Higher;679  update(Lower);680  return Lower;681}682 683 684HCE::ExtRoot::ExtRoot(const MachineOperand &Op) {685  // Always store ImmVal, since it's the field used for comparisons.686  V.ImmVal = 0;687  if (Op.isImm())688    ; // Keep 0. Do not use Op.getImm() for value here (treat 0 as the root).689  else if (Op.isFPImm())690    V.CFP = Op.getFPImm();691  else if (Op.isSymbol())692    V.SymbolName = Op.getSymbolName();693  else if (Op.isGlobal())694    V.GV = Op.getGlobal();695  else if (Op.isBlockAddress())696    V.BA = Op.getBlockAddress();697  else if (Op.isCPI() || Op.isTargetIndex() || Op.isJTI())698    V.ImmVal = Op.getIndex();699  else700    llvm_unreachable("Unexpected operand type");701 702  Kind = Op.getType();703  TF = Op.getTargetFlags();704}705 706bool HCE::ExtRoot::operator< (const HCE::ExtRoot &ER) const {707  if (Kind != ER.Kind)708    return Kind < ER.Kind;709  switch (Kind) {710    case MachineOperand::MO_Immediate:711    case MachineOperand::MO_TargetIndex:712    case MachineOperand::MO_ConstantPoolIndex:713    case MachineOperand::MO_JumpTableIndex:714      return V.ImmVal < ER.V.ImmVal;715    case MachineOperand::MO_FPImmediate: {716      const APFloat &ThisF = V.CFP->getValueAPF();717      const APFloat &OtherF = ER.V.CFP->getValueAPF();718      return ThisF.bitcastToAPInt().ult(OtherF.bitcastToAPInt());719    }720    case MachineOperand::MO_ExternalSymbol:721      return StringRef(V.SymbolName) < StringRef(ER.V.SymbolName);722    case MachineOperand::MO_GlobalAddress:723      // Do not use GUIDs, since they depend on the source path. Moving the724      // source file to a different directory could cause different GUID725      // values for a pair of given symbols. These symbols could then compare726      // "less" in one directory, but "greater" in another.727      assert(!V.GV->getName().empty() && !ER.V.GV->getName().empty());728      return V.GV->getName() < ER.V.GV->getName();729    case MachineOperand::MO_BlockAddress: {730      const BasicBlock *ThisB = V.BA->getBasicBlock();731      const BasicBlock *OtherB = ER.V.BA->getBasicBlock();732      assert(ThisB->getParent() == OtherB->getParent());733      const Function &F = *ThisB->getParent();734      return std::distance(F.begin(), ThisB->getIterator()) <735             std::distance(F.begin(), OtherB->getIterator());736    }737  }738  return V.ImmVal < ER.V.ImmVal;739}740 741HCE::ExtValue::ExtValue(const MachineOperand &Op) : ExtRoot(Op) {742  if (Op.isImm())743    Offset = Op.getImm();744  else if (Op.isFPImm() || Op.isJTI())745    Offset = 0;746  else if (Op.isSymbol() || Op.isGlobal() || Op.isBlockAddress() ||747           Op.isCPI() || Op.isTargetIndex())748    Offset = Op.getOffset();749  else750    llvm_unreachable("Unexpected operand type");751}752 753bool HCE::ExtValue::operator< (const HCE::ExtValue &EV) const {754  const ExtRoot &ER = *this;755  if (!(ER == ExtRoot(EV)))756    return ER < EV;757  return Offset < EV.Offset;758}759 760HCE::ExtValue::operator MachineOperand() const {761  switch (Kind) {762    case MachineOperand::MO_Immediate:763      return MachineOperand::CreateImm(V.ImmVal + Offset);764    case MachineOperand::MO_FPImmediate:765      assert(Offset == 0);766      return MachineOperand::CreateFPImm(V.CFP);767    case MachineOperand::MO_ExternalSymbol:768      assert(Offset == 0);769      return MachineOperand::CreateES(V.SymbolName, TF);770    case MachineOperand::MO_GlobalAddress:771      return MachineOperand::CreateGA(V.GV, Offset, TF);772    case MachineOperand::MO_BlockAddress:773      return MachineOperand::CreateBA(V.BA, Offset, TF);774    case MachineOperand::MO_TargetIndex:775      return MachineOperand::CreateTargetIndex(V.ImmVal, Offset, TF);776    case MachineOperand::MO_ConstantPoolIndex:777      return MachineOperand::CreateCPI(V.ImmVal, Offset, TF);778    case MachineOperand::MO_JumpTableIndex:779      assert(Offset == 0);780      return MachineOperand::CreateJTI(V.ImmVal, TF);781    default:782      llvm_unreachable("Unhandled kind");783 }784}785 786bool HCE::isStoreImmediate(unsigned Opc) const {787  switch (Opc) {788    case Hexagon::S4_storeirbt_io:789    case Hexagon::S4_storeirbf_io:790    case Hexagon::S4_storeirht_io:791    case Hexagon::S4_storeirhf_io:792    case Hexagon::S4_storeirit_io:793    case Hexagon::S4_storeirif_io:794    case Hexagon::S4_storeirb_io:795    case Hexagon::S4_storeirh_io:796    case Hexagon::S4_storeiri_io:797      return true;798    default:799      break;800  }801  return false;802}803 804bool HCE::isRegOffOpcode(unsigned Opc) const {805  switch (Opc) {806    case Hexagon::L2_loadrub_io:807    case Hexagon::L2_loadrb_io:808    case Hexagon::L2_loadruh_io:809    case Hexagon::L2_loadrh_io:810    case Hexagon::L2_loadri_io:811    case Hexagon::L2_loadrd_io:812    case Hexagon::L2_loadbzw2_io:813    case Hexagon::L2_loadbzw4_io:814    case Hexagon::L2_loadbsw2_io:815    case Hexagon::L2_loadbsw4_io:816    case Hexagon::L2_loadalignh_io:817    case Hexagon::L2_loadalignb_io:818    case Hexagon::L2_ploadrubt_io:819    case Hexagon::L2_ploadrubf_io:820    case Hexagon::L2_ploadrbt_io:821    case Hexagon::L2_ploadrbf_io:822    case Hexagon::L2_ploadruht_io:823    case Hexagon::L2_ploadruhf_io:824    case Hexagon::L2_ploadrht_io:825    case Hexagon::L2_ploadrhf_io:826    case Hexagon::L2_ploadrit_io:827    case Hexagon::L2_ploadrif_io:828    case Hexagon::L2_ploadrdt_io:829    case Hexagon::L2_ploadrdf_io:830    case Hexagon::S2_storerb_io:831    case Hexagon::S2_storerh_io:832    case Hexagon::S2_storerf_io:833    case Hexagon::S2_storeri_io:834    case Hexagon::S2_storerd_io:835    case Hexagon::S2_pstorerbt_io:836    case Hexagon::S2_pstorerbf_io:837    case Hexagon::S2_pstorerht_io:838    case Hexagon::S2_pstorerhf_io:839    case Hexagon::S2_pstorerft_io:840    case Hexagon::S2_pstorerff_io:841    case Hexagon::S2_pstorerit_io:842    case Hexagon::S2_pstorerif_io:843    case Hexagon::S2_pstorerdt_io:844    case Hexagon::S2_pstorerdf_io:845    case Hexagon::A2_addi:846      return true;847    default:848      break;849  }850  return false;851}852 853unsigned HCE::getRegOffOpcode(unsigned ExtOpc) const {854  // If there exists an instruction that takes a register and offset,855  // that corresponds to the ExtOpc, return it, otherwise return 0.856  using namespace Hexagon;857  switch (ExtOpc) {858    case A2_tfrsi:    return A2_addi;859    default:860      break;861  }862  const MCInstrDesc &D = HII->get(ExtOpc);863  if (D.mayLoad() || D.mayStore()) {864    uint64_t F = D.TSFlags;865    unsigned AM = (F >> HexagonII::AddrModePos) & HexagonII::AddrModeMask;866    switch (AM) {867      case HexagonII::Absolute:868      case HexagonII::AbsoluteSet:869      case HexagonII::BaseLongOffset:870        switch (ExtOpc) {871          case PS_loadrubabs:872          case L4_loadrub_ap:873          case L4_loadrub_ur:     return L2_loadrub_io;874          case PS_loadrbabs:875          case L4_loadrb_ap:876          case L4_loadrb_ur:      return L2_loadrb_io;877          case PS_loadruhabs:878          case L4_loadruh_ap:879          case L4_loadruh_ur:     return L2_loadruh_io;880          case PS_loadrhabs:881          case L4_loadrh_ap:882          case L4_loadrh_ur:      return L2_loadrh_io;883          case PS_loadriabs:884          case L4_loadri_ap:885          case L4_loadri_ur:      return L2_loadri_io;886          case PS_loadrdabs:887          case L4_loadrd_ap:888          case L4_loadrd_ur:      return L2_loadrd_io;889          case L4_loadbzw2_ap:890          case L4_loadbzw2_ur:    return L2_loadbzw2_io;891          case L4_loadbzw4_ap:892          case L4_loadbzw4_ur:    return L2_loadbzw4_io;893          case L4_loadbsw2_ap:894          case L4_loadbsw2_ur:    return L2_loadbsw2_io;895          case L4_loadbsw4_ap:896          case L4_loadbsw4_ur:    return L2_loadbsw4_io;897          case L4_loadalignh_ap:898          case L4_loadalignh_ur:  return L2_loadalignh_io;899          case L4_loadalignb_ap:900          case L4_loadalignb_ur:  return L2_loadalignb_io;901          case L4_ploadrubt_abs:  return L2_ploadrubt_io;902          case L4_ploadrubf_abs:  return L2_ploadrubf_io;903          case L4_ploadrbt_abs:   return L2_ploadrbt_io;904          case L4_ploadrbf_abs:   return L2_ploadrbf_io;905          case L4_ploadruht_abs:  return L2_ploadruht_io;906          case L4_ploadruhf_abs:  return L2_ploadruhf_io;907          case L4_ploadrht_abs:   return L2_ploadrht_io;908          case L4_ploadrhf_abs:   return L2_ploadrhf_io;909          case L4_ploadrit_abs:   return L2_ploadrit_io;910          case L4_ploadrif_abs:   return L2_ploadrif_io;911          case L4_ploadrdt_abs:   return L2_ploadrdt_io;912          case L4_ploadrdf_abs:   return L2_ploadrdf_io;913          case PS_storerbabs:914          case S4_storerb_ap:915          case S4_storerb_ur:     return S2_storerb_io;916          case PS_storerhabs:917          case S4_storerh_ap:918          case S4_storerh_ur:     return S2_storerh_io;919          case PS_storerfabs:920          case S4_storerf_ap:921          case S4_storerf_ur:     return S2_storerf_io;922          case PS_storeriabs:923          case S4_storeri_ap:924          case S4_storeri_ur:     return S2_storeri_io;925          case PS_storerdabs:926          case S4_storerd_ap:927          case S4_storerd_ur:     return S2_storerd_io;928          case S4_pstorerbt_abs:  return S2_pstorerbt_io;929          case S4_pstorerbf_abs:  return S2_pstorerbf_io;930          case S4_pstorerht_abs:  return S2_pstorerht_io;931          case S4_pstorerhf_abs:  return S2_pstorerhf_io;932          case S4_pstorerft_abs:  return S2_pstorerft_io;933          case S4_pstorerff_abs:  return S2_pstorerff_io;934          case S4_pstorerit_abs:  return S2_pstorerit_io;935          case S4_pstorerif_abs:  return S2_pstorerif_io;936          case S4_pstorerdt_abs:  return S2_pstorerdt_io;937          case S4_pstorerdf_abs:  return S2_pstorerdf_io;938          default:939            break;940        }941        break;942      case HexagonII::BaseImmOffset:943        if (!isStoreImmediate(ExtOpc))944          return ExtOpc;945        break;946      default:947        break;948    }949  }950  return 0;951}952 953unsigned HCE::getDirectRegReplacement(unsigned ExtOpc) const {954  switch (ExtOpc) {955    case Hexagon::A2_addi:          return Hexagon::A2_add;956    case Hexagon::A2_andir:         return Hexagon::A2_and;957    case Hexagon::A2_combineii:     return Hexagon::A4_combineri;958    case Hexagon::A2_orir:          return Hexagon::A2_or;959    case Hexagon::A2_paddif:        return Hexagon::A2_paddf;960    case Hexagon::A2_paddit:        return Hexagon::A2_paddt;961    case Hexagon::A2_subri:         return Hexagon::A2_sub;962    case Hexagon::A2_tfrsi:         return TargetOpcode::COPY;963    case Hexagon::A4_cmpbeqi:       return Hexagon::A4_cmpbeq;964    case Hexagon::A4_cmpbgti:       return Hexagon::A4_cmpbgt;965    case Hexagon::A4_cmpbgtui:      return Hexagon::A4_cmpbgtu;966    case Hexagon::A4_cmpheqi:       return Hexagon::A4_cmpheq;967    case Hexagon::A4_cmphgti:       return Hexagon::A4_cmphgt;968    case Hexagon::A4_cmphgtui:      return Hexagon::A4_cmphgtu;969    case Hexagon::A4_combineii:     return Hexagon::A4_combineir;970    case Hexagon::A4_combineir:     return TargetOpcode::REG_SEQUENCE;971    case Hexagon::A4_combineri:     return TargetOpcode::REG_SEQUENCE;972    case Hexagon::A4_rcmpeqi:       return Hexagon::A4_rcmpeq;973    case Hexagon::A4_rcmpneqi:      return Hexagon::A4_rcmpneq;974    case Hexagon::C2_cmoveif:       return Hexagon::A2_tfrpf;975    case Hexagon::C2_cmoveit:       return Hexagon::A2_tfrpt;976    case Hexagon::C2_cmpeqi:        return Hexagon::C2_cmpeq;977    case Hexagon::C2_cmpgti:        return Hexagon::C2_cmpgt;978    case Hexagon::C2_cmpgtui:       return Hexagon::C2_cmpgtu;979    case Hexagon::C2_muxii:         return Hexagon::C2_muxir;980    case Hexagon::C2_muxir:         return Hexagon::C2_mux;981    case Hexagon::C2_muxri:         return Hexagon::C2_mux;982    case Hexagon::C4_cmpltei:       return Hexagon::C4_cmplte;983    case Hexagon::C4_cmplteui:      return Hexagon::C4_cmplteu;984    case Hexagon::C4_cmpneqi:       return Hexagon::C4_cmpneq;985    case Hexagon::M2_accii:         return Hexagon::M2_acci;        // T -> T986    /* No M2_macsin */987    case Hexagon::M2_macsip:        return Hexagon::M2_maci;        // T -> T988    case Hexagon::M2_mpysin:        return Hexagon::M2_mpyi;989    case Hexagon::M2_mpysip:        return Hexagon::M2_mpyi;990    case Hexagon::M2_mpysmi:        return Hexagon::M2_mpyi;991    case Hexagon::M2_naccii:        return Hexagon::M2_nacci;       // T -> T992    case Hexagon::M4_mpyri_addi:    return Hexagon::M4_mpyri_addr;993    case Hexagon::M4_mpyri_addr:    return Hexagon::M4_mpyrr_addr;  // _ -> T994    case Hexagon::M4_mpyrr_addi:    return Hexagon::M4_mpyrr_addr;  // _ -> T995    case Hexagon::S4_addaddi:       return Hexagon::M2_acci;        // _ -> T996    case Hexagon::S4_addi_asl_ri:   return Hexagon::S2_asl_i_r_acc; // T -> T997    case Hexagon::S4_addi_lsr_ri:   return Hexagon::S2_lsr_i_r_acc; // T -> T998    case Hexagon::S4_andi_asl_ri:   return Hexagon::S2_asl_i_r_and; // T -> T999    case Hexagon::S4_andi_lsr_ri:   return Hexagon::S2_lsr_i_r_and; // T -> T1000    case Hexagon::S4_ori_asl_ri:    return Hexagon::S2_asl_i_r_or;  // T -> T1001    case Hexagon::S4_ori_lsr_ri:    return Hexagon::S2_lsr_i_r_or;  // T -> T1002    case Hexagon::S4_subaddi:       return Hexagon::M2_subacc;      // _ -> T1003    case Hexagon::S4_subi_asl_ri:   return Hexagon::S2_asl_i_r_nac; // T -> T1004    case Hexagon::S4_subi_lsr_ri:   return Hexagon::S2_lsr_i_r_nac; // T -> T1005 1006    // Store-immediates:1007    case Hexagon::S4_storeirbf_io:  return Hexagon::S2_pstorerbf_io;1008    case Hexagon::S4_storeirb_io:   return Hexagon::S2_storerb_io;1009    case Hexagon::S4_storeirbt_io:  return Hexagon::S2_pstorerbt_io;1010    case Hexagon::S4_storeirhf_io:  return Hexagon::S2_pstorerhf_io;1011    case Hexagon::S4_storeirh_io:   return Hexagon::S2_storerh_io;1012    case Hexagon::S4_storeirht_io:  return Hexagon::S2_pstorerht_io;1013    case Hexagon::S4_storeirif_io:  return Hexagon::S2_pstorerif_io;1014    case Hexagon::S4_storeiri_io:   return Hexagon::S2_storeri_io;1015    case Hexagon::S4_storeirit_io:  return Hexagon::S2_pstorerit_io;1016 1017    default:1018      break;1019  }1020  return 0;1021}1022 1023// Return the allowable deviation from the current value of Rb (i.e. the1024// range of values that can be added to the current value) which the1025// instruction MI can accommodate.1026// The instruction MI is a user of register Rb, which is defined via an1027// extender. It may be possible for MI to be tweaked to work for a register1028// defined with a slightly different value. For example1029//   ... = L2_loadrub_io Rb, 11030// can be modified to be1031//   ... = L2_loadrub_io Rb', 01032// if Rb' = Rb+1.1033// The range for Rb would be [Min+1, Max+1], where [Min, Max] is a range1034// for L2_loadrub with offset 0. That means that Rb could be replaced with1035// Rc, where Rc-Rb belongs to [Min+1, Max+1].1036OffsetRange HCE::getOffsetRange(Register Rb, const MachineInstr &MI) const {1037  unsigned Opc = MI.getOpcode();1038  // Instructions that are constant-extended may be replaced with something1039  // else that no longer offers the same range as the original.1040  if (!isRegOffOpcode(Opc) || HII->isConstExtended(MI))1041    return OffsetRange::zero();1042 1043  if (Opc == Hexagon::A2_addi) {1044    const MachineOperand &Op1 = MI.getOperand(1), &Op2 = MI.getOperand(2);1045    if (Rb != Register(Op1) || !Op2.isImm())1046      return OffsetRange::zero();1047    OffsetRange R = { -(1<<15)+1, (1<<15)-1, 1 };1048    return R.shift(Op2.getImm());1049  }1050 1051  // HII::getBaseAndOffsetPosition returns the increment position as "offset".1052  if (HII->isPostIncrement(MI))1053    return OffsetRange::zero();1054 1055  const MCInstrDesc &D = HII->get(Opc);1056  assert(D.mayLoad() || D.mayStore());1057 1058  unsigned BaseP, OffP;1059  if (!HII->getBaseAndOffsetPosition(MI, BaseP, OffP) ||1060      Rb != Register(MI.getOperand(BaseP)) ||1061      !MI.getOperand(OffP).isImm())1062    return OffsetRange::zero();1063 1064  uint64_t F = (D.TSFlags >> HexagonII::MemAccessSizePos) &1065                  HexagonII::MemAccesSizeMask;1066  uint8_t A = HexagonII::getMemAccessSizeInBytes(HexagonII::MemAccessSize(F));1067  unsigned L = Log2_32(A);1068  unsigned S = 10+L;  // sint11_L1069  int32_t Min = -alignDown((1<<S)-1, A);1070 1071  // The range will be shifted by Off. To prefer non-negative offsets,1072  // adjust Max accordingly.1073  int32_t Off = MI.getOperand(OffP).getImm();1074  int32_t Max = Off >= 0 ? 0 : -Off;1075 1076  OffsetRange R = { Min, Max, A };1077  return R.shift(Off);1078}1079 1080// Return the allowable deviation from the current value of the extender ED,1081// for which the instruction corresponding to ED can be modified without1082// using an extender.1083// The instruction uses the extender directly. It will be replaced with1084// another instruction, say MJ, where the extender will be replaced with a1085// register. MJ can allow some variability with respect to the value of1086// that register, as is the case with indexed memory instructions.1087OffsetRange HCE::getOffsetRange(const ExtDesc &ED) const {1088  // The only way that there can be a non-zero range available is if1089  // the instruction using ED will be converted to an indexed memory1090  // instruction.1091  unsigned IdxOpc = getRegOffOpcode(ED.UseMI->getOpcode());1092  switch (IdxOpc) {1093    case 0:1094      return OffsetRange::zero();1095    case Hexagon::A2_addi:    // s161096      return { -32767, 32767, 1 };1097    case Hexagon::A2_subri:   // s101098      return { -511, 511, 1 };1099  }1100 1101  if (!ED.UseMI->mayLoad() && !ED.UseMI->mayStore())1102    return OffsetRange::zero();1103  const MCInstrDesc &D = HII->get(IdxOpc);1104  uint64_t F = (D.TSFlags >> HexagonII::MemAccessSizePos) &1105                  HexagonII::MemAccesSizeMask;1106  uint8_t A = HexagonII::getMemAccessSizeInBytes(HexagonII::MemAccessSize(F));1107  unsigned L = Log2_32(A);1108  unsigned S = 10+L;  // sint11_L1109  int32_t Min = -alignDown((1<<S)-1, A);1110  int32_t Max = 0;  // Force non-negative offsets.1111  return { Min, Max, A };1112}1113 1114// Get the allowable deviation from the current value of Rd by checking1115// all uses of Rd.1116OffsetRange HCE::getOffsetRange(Register Rd) const {1117  OffsetRange Range;1118  for (const MachineOperand &Op : MRI->use_operands(Rd.Reg)) {1119    // Make sure that the register being used by this operand is identical1120    // to the register that was defined: using a different subregister1121    // precludes any non-trivial range.1122    if (Rd != Register(Op))1123      return OffsetRange::zero();1124    Range.intersect(getOffsetRange(Rd, *Op.getParent()));1125  }1126  return Range;1127}1128 1129void HCE::recordExtender(MachineInstr &MI, unsigned OpNum) {1130  unsigned Opc = MI.getOpcode();1131  ExtDesc ED;1132  ED.OpNum = OpNum;1133 1134  bool IsLoad = MI.mayLoad();1135  bool IsStore = MI.mayStore();1136 1137  // Fixed stack slots have negative indexes, and they cannot be used1138  // with Register::stackSlotIndex and Register::index2StackSlot. This is1139  // somewhat unfortunate, but should not be a frequent thing.1140  for (MachineOperand &Op : MI.operands())1141    if (Op.isFI() && Op.getIndex() < 0)1142      return;1143 1144  if (IsLoad || IsStore) {1145    unsigned AM = HII->getAddrMode(MI);1146    switch (AM) {1147      // (Re: ##Off + Rb<<S) = Rd: ##Val1148      case HexagonII::Absolute:       // (__: ## + __<<_)1149        break;1150      case HexagonII::AbsoluteSet:    // (Rd: ## + __<<_)1151        ED.Rd = MI.getOperand(OpNum-1);1152        ED.IsDef = true;1153        break;1154      case HexagonII::BaseImmOffset:  // (__: ## + Rs<<0)1155        // Store-immediates are treated as non-memory operations, since1156        // it's the value being stored that is extended (as opposed to1157        // a part of the address).1158        if (!isStoreImmediate(Opc))1159          ED.Expr.Rs = MI.getOperand(OpNum-1);1160        break;1161      case HexagonII::BaseLongOffset: // (__: ## + Rs<<S)1162        ED.Expr.Rs = MI.getOperand(OpNum-2);1163        ED.Expr.S = MI.getOperand(OpNum-1).getImm();1164        break;1165      default:1166        llvm_unreachable("Unhandled memory instruction");1167    }1168  } else {1169    switch (Opc) {1170      case Hexagon::A2_tfrsi:         // (Rd: ## + __<<_)1171        ED.Rd = MI.getOperand(0);1172        ED.IsDef = true;1173        break;1174      case Hexagon::A2_combineii:     // (Rd: ## + __<<_)1175      case Hexagon::A4_combineir:1176        ED.Rd = { MI.getOperand(0).getReg(), Hexagon::isub_hi };1177        ED.IsDef = true;1178        break;1179      case Hexagon::A4_combineri:     // (Rd: ## + __<<_)1180        ED.Rd = { MI.getOperand(0).getReg(), Hexagon::isub_lo };1181        ED.IsDef = true;1182        break;1183      case Hexagon::A2_addi:          // (Rd: ## + Rs<<0)1184        ED.Rd = MI.getOperand(0);1185        ED.Expr.Rs = MI.getOperand(OpNum-1);1186        break;1187      case Hexagon::M2_accii:         // (__: ## + Rs<<0)1188      case Hexagon::M2_naccii:1189      case Hexagon::S4_addaddi:1190        ED.Expr.Rs = MI.getOperand(OpNum-1);1191        break;1192      case Hexagon::A2_subri:         // (Rd: ## - Rs<<0)1193        ED.Rd = MI.getOperand(0);1194        ED.Expr.Rs = MI.getOperand(OpNum+1);1195        ED.Expr.Neg = true;1196        break;1197      case Hexagon::S4_subaddi:       // (__: ## - Rs<<0)1198        ED.Expr.Rs = MI.getOperand(OpNum+1);1199        ED.Expr.Neg = true;1200        break;1201      default:                        // (__: ## + __<<_)1202        break;1203    }1204  }1205 1206  ED.UseMI = &MI;1207 1208  // Ignore unnamed globals.1209  ExtRoot ER(ED.getOp());1210  if (ER.Kind == MachineOperand::MO_GlobalAddress)1211    if (ER.V.GV->getName().empty())1212      return;1213  // Ignore block address that points to block in another function1214  if (ER.Kind == MachineOperand::MO_BlockAddress)1215    if (ER.V.BA->getFunction() != &(MI.getMF()->getFunction()))1216      return;1217  Extenders.push_back(ED);1218}1219 1220void HCE::collectInstr(MachineInstr &MI) {1221  if (!HII->isConstExtended(MI))1222    return;1223 1224  // Skip some non-convertible instructions.1225  unsigned Opc = MI.getOpcode();1226  switch (Opc) {1227    case Hexagon::M2_macsin:  // There is no Rx -= mpyi(Rs,Rt).1228    case Hexagon::C4_addipc:1229    case Hexagon::S4_or_andi:1230    case Hexagon::S4_or_andix:1231    case Hexagon::S4_or_ori:1232      return;1233  }1234  recordExtender(MI, HII->getCExtOpNum(MI));1235}1236 1237void HCE::collect(MachineFunction &MF) {1238  Extenders.clear();1239  for (MachineBasicBlock &MBB : MF) {1240    // Skip unreachable blocks.1241    if (MBB.getNumber() == -1)1242      continue;1243    for (MachineInstr &MI : MBB)1244      collectInstr(MI);1245  }1246}1247 1248void HCE::assignInits(const ExtRoot &ER, unsigned Begin, unsigned End,1249      AssignmentMap &IMap) {1250  // Basic correctness: make sure that all extenders in the range [Begin..End)1251  // share the same root ER.1252  for (unsigned I = Begin; I != End; ++I)1253    assert(ER == ExtRoot(Extenders[I].getOp()));1254 1255  // Construct the list of ranges, such that for each P in Ranges[I],1256  // a register Reg = ER+P can be used in place of Extender[I]. If the1257  // instruction allows, uses in the form of Reg+Off are considered1258  // (here, Off = required_value - P).1259  std::vector<OffsetRange> Ranges(End-Begin);1260 1261  // For each extender that is a def, visit all uses of the defined register,1262  // and produce an offset range that works for all uses. The def doesn't1263  // have to be checked, because it can become dead if all uses can be updated1264  // to use a different reg/offset.1265  for (unsigned I = Begin; I != End; ++I) {1266    const ExtDesc &ED = Extenders[I];1267    if (!ED.IsDef)1268      continue;1269    ExtValue EV(ED);1270    LLVM_DEBUG(dbgs() << " =" << I << ". " << EV << "  " << ED << '\n');1271    assert(ED.Rd.Reg != 0);1272    Ranges[I-Begin] = getOffsetRange(ED.Rd).shift(EV.Offset);1273    // A2_tfrsi is a special case: it will be replaced with A2_addi, which1274    // has a 16-bit signed offset. This means that A2_tfrsi not only has a1275    // range coming from its uses, but also from the fact that its replacement1276    // has a range as well.1277    if (ED.UseMI->getOpcode() == Hexagon::A2_tfrsi) {1278      int32_t D = alignDown(32767, Ranges[I-Begin].Align); // XXX hardcoded1279      Ranges[I-Begin].extendBy(-D).extendBy(D);1280    }1281  }1282 1283  // Visit all non-def extenders. For each one, determine the offset range1284  // available for it.1285  for (unsigned I = Begin; I != End; ++I) {1286    const ExtDesc &ED = Extenders[I];1287    if (ED.IsDef)1288      continue;1289    ExtValue EV(ED);1290    LLVM_DEBUG(dbgs() << "  " << I << ". " << EV << "  " << ED << '\n');1291    OffsetRange Dev = getOffsetRange(ED);1292    Ranges[I-Begin].intersect(Dev.shift(EV.Offset));1293  }1294 1295  // Here for each I there is a corresponding Range[I]. Construct the1296  // inverse map, that to each range will assign the set of indexes in1297  // [Begin..End) that this range corresponds to.1298  std::map<OffsetRange, IndexList> RangeMap;1299  for (unsigned I = Begin; I != End; ++I)1300    RangeMap[Ranges[I-Begin]].insert(I);1301 1302  LLVM_DEBUG({1303    dbgs() << "Ranges\n";1304    for (unsigned I = Begin; I != End; ++I)1305      dbgs() << "  " << I << ". " << Ranges[I-Begin] << '\n';1306    dbgs() << "RangeMap\n";1307    for (auto &P : RangeMap) {1308      dbgs() << "  " << P.first << " ->";1309      for (unsigned I : P.second)1310        dbgs() << ' ' << I;1311      dbgs() << '\n';1312    }1313  });1314 1315  // Select the definition points, and generate the assignment between1316  // these points and the uses.1317 1318  RangeTree Tree;1319  for (const OffsetRange &R : Ranges)1320    Tree.add(R);1321  SmallVector<RangeTree::Node*,8> Nodes;1322  Tree.order(Nodes);1323 1324  auto MaxAlign = [](const SmallVectorImpl<RangeTree::Node*> &Nodes,1325                     uint8_t Align, uint8_t Offset) {1326    for (RangeTree::Node *N : Nodes) {1327      if (N->Range.Align <= Align || N->Range.Offset < Offset)1328        continue;1329      if ((N->Range.Offset - Offset) % Align != 0)1330        continue;1331      Align = N->Range.Align;1332      Offset = N->Range.Offset;1333    }1334    return std::make_pair(Align, Offset);1335  };1336 1337  // Construct the set of all potential definition points from the endpoints1338  // of the ranges. If a given endpoint also belongs to a different range,1339  // but with a higher alignment, also consider the more-highly-aligned1340  // value of this endpoint.1341  std::set<int32_t> CandSet;1342  for (RangeTree::Node *N : Nodes) {1343    const OffsetRange &R = N->Range;1344    auto P0 = MaxAlign(Tree.nodesWith(R.Min, false), R.Align, R.Offset);1345    CandSet.insert(R.Min);1346    if (R.Align < P0.first)1347      CandSet.insert(adjustUp(R.Min, P0.first, P0.second));1348    auto P1 = MaxAlign(Tree.nodesWith(R.Max, false), R.Align, R.Offset);1349    CandSet.insert(R.Max);1350    if (R.Align < P1.first)1351      CandSet.insert(adjustDown(R.Max, P1.first, P1.second));1352  }1353 1354  // Build the assignment map: candidate C -> { list of extender indexes }.1355  // This has to be done iteratively:1356  // - pick the candidate that covers the maximum number of extenders,1357  // - add the candidate to the map,1358  // - remove the extenders from the pool.1359  while (true) {1360    using CMap = std::map<int32_t,unsigned>;1361    CMap Counts;1362    for (auto It = CandSet.begin(), Et = CandSet.end(); It != Et; ) {1363      auto &&V = Tree.nodesWith(*It);1364      unsigned N = std::accumulate(V.begin(), V.end(), 0u,1365                    [](unsigned Acc, const RangeTree::Node *N) {1366                      return Acc + N->Count;1367                    });1368      if (N != 0)1369        Counts.insert({*It, N});1370      It = (N != 0) ? std::next(It) : CandSet.erase(It);1371    }1372    if (Counts.empty())1373      break;1374 1375    // Find the best candidate with respect to the number of extenders covered.1376    auto BestIt = llvm::max_element(1377        Counts, [](const CMap::value_type &A, const CMap::value_type &B) {1378          return A.second < B.second || (A.second == B.second && A < B);1379        });1380    int32_t Best = BestIt->first;1381    ExtValue BestV(ER, Best);1382    for (RangeTree::Node *N : Tree.nodesWith(Best)) {1383      for (unsigned I : RangeMap[N->Range])1384        IMap[{BestV,Extenders[I].Expr}].insert(I);1385      Tree.erase(N);1386    }1387  }1388 1389  LLVM_DEBUG(dbgs() << "IMap (before fixup) = " << PrintIMap(IMap, *HRI));1390 1391  // There is some ambiguity in what initializer should be used, if the1392  // descriptor's subexpression is non-trivial: it can be the entire1393  // subexpression (which is what has been done so far), or it can be1394  // the extender's value itself, if all corresponding extenders have the1395  // exact value of the initializer (i.e. require offset of 0).1396 1397  // To reduce the number of initializers, merge such special cases.1398  for (std::pair<const ExtenderInit,IndexList> &P : IMap) {1399    // Skip trivial initializers.1400    if (P.first.second.trivial())1401      continue;1402    // If the corresponding trivial initializer does not exist, skip this1403    // entry.1404    const ExtValue &EV = P.first.first;1405    AssignmentMap::iterator F = IMap.find({EV, ExtExpr()});1406    if (F == IMap.end())1407      continue;1408 1409    // Finally, check if all extenders have the same value as the initializer.1410    // Make sure that extenders that are a part of a stack address are not1411    // merged with those that aren't. Stack addresses need an offset field1412    // (to be used by frame index elimination), while non-stack expressions1413    // can be replaced with forms (such as rr) that do not have such a field.1414    // Example:1415    //1416    // Collected 3 extenders1417    //  =2. imm:0  off:32968  bb#2: %7 = ## + __ << 0, def1418    //   0. imm:0  off:267  bb#0: __ = ## + SS#1 << 01419    //   1. imm:0  off:267  bb#1: __ = ## + SS#1 << 01420    // Ranges1421    //   0. [-756,267]a1+01422    //   1. [-756,267]a1+01423    //   2. [201,65735]a1+01424    // RangeMap1425    //   [-756,267]a1+0 -> 0 11426    //   [201,65735]a1+0 -> 21427    // IMap (before fixup) = {1428    //   [imm:0  off:267, ## + __ << 0] -> { 2 }1429    //   [imm:0  off:267, ## + SS#1 << 0] -> { 0 1 }1430    // }1431    // IMap (after fixup) = {1432    //   [imm:0  off:267, ## + __ << 0] -> { 2 0 1 }1433    //   [imm:0  off:267, ## + SS#1 << 0] -> { }1434    // }1435    // Inserted def in bb#0 for initializer: [imm:0  off:267, ## + __ << 0]1436    //   %12:intregs = A2_tfrsi 2671437    //1438    // The result was1439    //   %12:intregs = A2_tfrsi 2671440    //   S4_pstorerbt_rr %3, %12, %stack.1, 0, killed %41441    // Which became1442    //   r0 = #2671443    //   if (p0.new) memb(r0+r29<<#4) = r21444 1445    bool IsStack = any_of(F->second, [this](unsigned I) {1446                      return Extenders[I].Expr.Rs.isSlot();1447                   });1448    auto SameValue = [&EV,this,IsStack](unsigned I) {1449      const ExtDesc &ED = Extenders[I];1450      return ED.Expr.Rs.isSlot() == IsStack &&1451             ExtValue(ED).Offset == EV.Offset;1452    };1453    if (all_of(P.second, SameValue)) {1454      F->second.insert_range(P.second);1455      P.second.clear();1456    }1457  }1458 1459  LLVM_DEBUG(dbgs() << "IMap (after fixup) = " << PrintIMap(IMap, *HRI));1460}1461 1462void HCE::calculatePlacement(const ExtenderInit &ExtI, const IndexList &Refs,1463      LocDefList &Defs) {1464  if (Refs.empty())1465    return;1466 1467  // The placement calculation is somewhat simple right now: it finds a1468  // single location for the def that dominates all refs. Since this may1469  // place the def far from the uses, producing several locations for1470  // defs that collectively dominate all refs could be better.1471  // For now only do the single one.1472  DenseSet<MachineBasicBlock*> Blocks;1473  DenseSet<MachineInstr*> RefMIs;1474  const ExtDesc &ED0 = Extenders[Refs[0]];1475  MachineBasicBlock *DomB = ED0.UseMI->getParent();1476  RefMIs.insert(ED0.UseMI);1477  Blocks.insert(DomB);1478  for (unsigned i = 1, e = Refs.size(); i != e; ++i) {1479    const ExtDesc &ED = Extenders[Refs[i]];1480    MachineBasicBlock *MBB = ED.UseMI->getParent();1481    RefMIs.insert(ED.UseMI);1482    DomB = MDT->findNearestCommonDominator(DomB, MBB);1483    Blocks.insert(MBB);1484  }1485 1486#ifndef NDEBUG1487  // The block DomB should be dominated by the def of each register used1488  // in the initializer.1489  Register Rs = ExtI.second.Rs;  // Only one reg allowed now.1490  const MachineInstr *DefI = Rs.isVReg() ? MRI->getVRegDef(Rs.Reg) : nullptr;1491 1492  // This should be guaranteed given that the entire expression is used1493  // at each instruction in Refs. Add an assertion just in case.1494  assert(!DefI || MDT->dominates(DefI->getParent(), DomB));1495#endif1496 1497  MachineBasicBlock::iterator It;1498  if (Blocks.count(DomB)) {1499    // Try to find the latest possible location for the def.1500    MachineBasicBlock::iterator End = DomB->end();1501    for (It = DomB->begin(); It != End; ++It)1502      if (RefMIs.count(&*It))1503        break;1504    assert(It != End && "Should have found a ref in DomB");1505  } else {1506    // DomB does not contain any refs.1507    It = DomB->getFirstTerminator();1508  }1509  Loc DefLoc(DomB, It);1510  Defs.emplace_back(DefLoc, Refs);1511}1512 1513HCE::Register HCE::insertInitializer(Loc DefL, const ExtenderInit &ExtI) {1514  llvm::Register DefR = MRI->createVirtualRegister(&Hexagon::IntRegsRegClass);1515  MachineBasicBlock &MBB = *DefL.Block;1516  MachineBasicBlock::iterator At = DefL.At;1517  DebugLoc dl = DefL.Block->findDebugLoc(DefL.At);1518  const ExtValue &EV = ExtI.first;1519  MachineOperand ExtOp(EV);1520 1521  const ExtExpr &Ex = ExtI.second;1522  const MachineInstr *InitI = nullptr;1523 1524  if (Ex.Rs.isSlot()) {1525    assert(Ex.S == 0 && "Cannot have a shift of a stack slot");1526    assert(!Ex.Neg && "Cannot subtract a stack slot");1527    // DefR = PS_fi Rb,##EV1528    InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::PS_fi), DefR)1529              .add(MachineOperand(Ex.Rs))1530              .add(ExtOp);1531  } else {1532    assert((Ex.Rs.Reg == 0 || Ex.Rs.isVReg()) && "Expecting virtual register");1533    if (Ex.trivial()) {1534      // DefR = ##EV1535      InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_tfrsi), DefR)1536                .add(ExtOp);1537    } else if (Ex.S == 0) {1538      if (Ex.Neg) {1539        // DefR = sub(##EV,Rb)1540        InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_subri), DefR)1541                  .add(ExtOp)1542                  .add(MachineOperand(Ex.Rs));1543      } else {1544        // DefR = add(Rb,##EV)1545        InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_addi), DefR)1546                  .add(MachineOperand(Ex.Rs))1547                  .add(ExtOp);1548      }1549    } else {1550      if (HST->useCompound()) {1551        unsigned NewOpc = Ex.Neg ? Hexagon::S4_subi_asl_ri1552                                 : Hexagon::S4_addi_asl_ri;1553        // DefR = add(##EV,asl(Rb,S))1554        InitI = BuildMI(MBB, At, dl, HII->get(NewOpc), DefR)1555                  .add(ExtOp)1556                  .add(MachineOperand(Ex.Rs))1557                  .addImm(Ex.S);1558      } else {1559        // No compounds are available. It is not clear whether we should1560        // even process such extenders where the initializer cannot be1561        // a single instruction, but do it for now.1562        llvm::Register TmpR = MRI->createVirtualRegister(&Hexagon::IntRegsRegClass);1563        BuildMI(MBB, At, dl, HII->get(Hexagon::S2_asl_i_r), TmpR)1564          .add(MachineOperand(Ex.Rs))1565          .addImm(Ex.S);1566        if (Ex.Neg)1567          InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_subri), DefR)1568                    .add(ExtOp)1569                    .add(MachineOperand(Register(TmpR, 0)));1570        else1571          InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_addi), DefR)1572                    .add(MachineOperand(Register(TmpR, 0)))1573                    .add(ExtOp);1574      }1575    }1576  }1577 1578  assert(InitI);1579  (void)InitI;1580  LLVM_DEBUG(dbgs() << "Inserted def in bb#" << MBB.getNumber()1581                    << " for initializer: " << PrintInit(ExtI, *HRI) << "\n  "1582                    << *InitI);1583  return { DefR, 0 };1584}1585 1586// Replace the extender at index Idx with the register ExtR.1587bool HCE::replaceInstrExact(const ExtDesc &ED, Register ExtR) {1588  MachineInstr &MI = *ED.UseMI;1589  MachineBasicBlock &MBB = *MI.getParent();1590  MachineBasicBlock::iterator At = MI.getIterator();1591  DebugLoc dl = MI.getDebugLoc();1592  unsigned ExtOpc = MI.getOpcode();1593 1594  // With a few exceptions, direct replacement amounts to creating an1595  // instruction with a corresponding register opcode, with all operands1596  // the same, except for the register used in place of the extender.1597  unsigned RegOpc = getDirectRegReplacement(ExtOpc);1598 1599  if (RegOpc == TargetOpcode::REG_SEQUENCE) {1600    if (ExtOpc == Hexagon::A4_combineri)1601      BuildMI(MBB, At, dl, HII->get(RegOpc))1602        .add(MI.getOperand(0))1603        .add(MI.getOperand(1))1604        .addImm(Hexagon::isub_hi)1605        .add(MachineOperand(ExtR))1606        .addImm(Hexagon::isub_lo);1607    else if (ExtOpc == Hexagon::A4_combineir)1608      BuildMI(MBB, At, dl, HII->get(RegOpc))1609        .add(MI.getOperand(0))1610        .add(MachineOperand(ExtR))1611        .addImm(Hexagon::isub_hi)1612        .add(MI.getOperand(2))1613        .addImm(Hexagon::isub_lo);1614    else1615      llvm_unreachable("Unexpected opcode became REG_SEQUENCE");1616    MBB.erase(MI);1617    return true;1618  }1619  if (ExtOpc == Hexagon::C2_cmpgei || ExtOpc == Hexagon::C2_cmpgeui) {1620    unsigned NewOpc = ExtOpc == Hexagon::C2_cmpgei ? Hexagon::C2_cmplt1621                                                   : Hexagon::C2_cmpltu;1622    BuildMI(MBB, At, dl, HII->get(NewOpc))1623      .add(MI.getOperand(0))1624      .add(MachineOperand(ExtR))1625      .add(MI.getOperand(1));1626    MBB.erase(MI);1627    return true;1628  }1629 1630  if (RegOpc != 0) {1631    MachineInstrBuilder MIB = BuildMI(MBB, At, dl, HII->get(RegOpc));1632    unsigned RegN = ED.OpNum;1633    // Copy all operands except the one that has the extender.1634    for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {1635      if (i != RegN)1636        MIB.add(MI.getOperand(i));1637      else1638        MIB.add(MachineOperand(ExtR));1639    }1640    MIB.cloneMemRefs(MI);1641    MBB.erase(MI);1642    return true;1643  }1644 1645  if (MI.mayLoadOrStore() && !isStoreImmediate(ExtOpc)) {1646    // For memory instructions, there is an asymmetry in the addressing1647    // modes. Addressing modes allowing extenders can be replaced with1648    // addressing modes that use registers, but the order of operands1649    // (or even their number) may be different.1650    // Replacements:1651    //   BaseImmOffset (io)  -> BaseRegOffset (rr)1652    //   BaseLongOffset (ur) -> BaseRegOffset (rr)1653    unsigned RegOpc, Shift;1654    unsigned AM = HII->getAddrMode(MI);1655    if (AM == HexagonII::BaseImmOffset) {1656      RegOpc = HII->changeAddrMode_io_rr(ExtOpc);1657      Shift = 0;1658    } else if (AM == HexagonII::BaseLongOffset) {1659      // Loads:  Rd = L4_loadri_ur Rs, S, ##1660      // Stores: S4_storeri_ur Rs, S, ##, Rt1661      RegOpc = HII->changeAddrMode_ur_rr(ExtOpc);1662      Shift = MI.getOperand(MI.mayLoad() ? 2 : 1).getImm();1663    } else {1664      llvm_unreachable("Unexpected addressing mode");1665    }1666#ifndef NDEBUG1667    if (RegOpc == -1u) {1668      dbgs() << "\nExtOpc: " << HII->getName(ExtOpc) << " has no rr version\n";1669      llvm_unreachable("No corresponding rr instruction");1670    }1671#endif1672 1673    unsigned BaseP, OffP;1674    HII->getBaseAndOffsetPosition(MI, BaseP, OffP);1675 1676    // Build an rr instruction: (RegOff + RegBase<<0)1677    MachineInstrBuilder MIB = BuildMI(MBB, At, dl, HII->get(RegOpc));1678    // First, add the def for loads.1679    if (MI.mayLoad())1680      MIB.add(getLoadResultOp(MI));1681    // Handle possible predication.1682    if (HII->isPredicated(MI))1683      MIB.add(getPredicateOp(MI));1684    // Build the address.1685    MIB.add(MachineOperand(ExtR));      // RegOff1686    MIB.add(MI.getOperand(BaseP));      // RegBase1687    MIB.addImm(Shift);                  // << Shift1688    // Add the stored value for stores.1689    if (MI.mayStore())1690      MIB.add(getStoredValueOp(MI));1691    MIB.cloneMemRefs(MI);1692    MBB.erase(MI);1693    return true;1694  }1695 1696#ifndef NDEBUG1697  dbgs() << '\n' << MI;1698#endif1699  llvm_unreachable("Unhandled exact replacement");1700  return false;1701}1702 1703// Replace the extender ED with a form corresponding to the initializer ExtI.1704bool HCE::replaceInstrExpr(const ExtDesc &ED, const ExtenderInit &ExtI,1705      Register ExtR, int32_t &Diff) {1706  MachineInstr &MI = *ED.UseMI;1707  MachineBasicBlock &MBB = *MI.getParent();1708  MachineBasicBlock::iterator At = MI.getIterator();1709  DebugLoc dl = MI.getDebugLoc();1710  unsigned ExtOpc = MI.getOpcode();1711 1712  if (ExtOpc == Hexagon::A2_tfrsi) {1713    // A2_tfrsi is a special case: it's replaced with A2_addi, which introduces1714    // another range. One range is the one that's common to all tfrsi's uses,1715    // this one is the range of immediates in A2_addi. When calculating ranges,1716    // the addi's 16-bit argument was included, so now we need to make it such1717    // that the produced value is in the range for the uses alone.1718    // Most of the time, simply adding Diff will make the addi produce exact1719    // result, but if Diff is outside of the 16-bit range, some adjustment1720    // will be needed.1721    unsigned IdxOpc = getRegOffOpcode(ExtOpc);1722    assert(IdxOpc == Hexagon::A2_addi);1723 1724    // Clamp Diff to the 16 bit range.1725    int32_t D = isInt<16>(Diff) ? Diff : (Diff > 0 ? 32767 : -32768);1726    if (Diff > 32767) {1727      // Split Diff into two values: one that is close to min/max int16,1728      // and the other being the rest, and such that both have the same1729      // "alignment" as Diff.1730      uint32_t UD = Diff;1731      OffsetRange R = getOffsetRange(MI.getOperand(0));1732      uint32_t A = std::min<uint32_t>(R.Align, 1u << llvm::countr_zero(UD));1733      D &= ~(A-1);1734    }1735    BuildMI(MBB, At, dl, HII->get(IdxOpc))1736      .add(MI.getOperand(0))1737      .add(MachineOperand(ExtR))1738      .addImm(D);1739    Diff -= D;1740#ifndef NDEBUG1741    // Make sure the output is within allowable range for uses.1742    // "Diff" is a difference in the "opposite direction", i.e. Ext - DefV,1743    // not DefV - Ext, as the getOffsetRange would calculate.1744    OffsetRange Uses = getOffsetRange(MI.getOperand(0));1745    if (!Uses.contains(-Diff))1746      dbgs() << "Diff: " << -Diff << " out of range " << Uses1747             << " for " << MI;1748    assert(Uses.contains(-Diff));1749#endif1750    MBB.erase(MI);1751    return true;1752  }1753 1754  const ExtValue &EV = ExtI.first; (void)EV;1755  const ExtExpr &Ex = ExtI.second; (void)Ex;1756 1757  if (ExtOpc == Hexagon::A2_addi || ExtOpc == Hexagon::A2_subri) {1758    // If addi/subri are replaced with the exactly matching initializer,1759    // they amount to COPY.1760    // Check that the initializer is an exact match (for simplicity).1761#ifndef NDEBUG1762    bool IsAddi = ExtOpc == Hexagon::A2_addi;1763    const MachineOperand &RegOp = MI.getOperand(IsAddi ? 1 : 2);1764    const MachineOperand &ImmOp = MI.getOperand(IsAddi ? 2 : 1);1765    assert(Ex.Rs == RegOp && EV == ImmOp && Ex.Neg != IsAddi &&1766           "Initializer mismatch");1767#endif1768    BuildMI(MBB, At, dl, HII->get(TargetOpcode::COPY))1769      .add(MI.getOperand(0))1770      .add(MachineOperand(ExtR));1771    Diff = 0;1772    MBB.erase(MI);1773    return true;1774  }1775  if (ExtOpc == Hexagon::M2_accii || ExtOpc == Hexagon::M2_naccii ||1776      ExtOpc == Hexagon::S4_addaddi || ExtOpc == Hexagon::S4_subaddi) {1777    // M2_accii:    add(Rt,add(Rs,V)) (tied)1778    // M2_naccii:   sub(Rt,add(Rs,V))1779    // S4_addaddi:  add(Rt,add(Rs,V))1780    // S4_subaddi:  add(Rt,sub(V,Rs))1781    // Check that Rs and V match the initializer expression. The Rs+V is the1782    // combination that is considered "subexpression" for V, although Rx+V1783    // would also be valid.1784#ifndef NDEBUG1785    bool IsSub = ExtOpc == Hexagon::S4_subaddi;1786    Register Rs = MI.getOperand(IsSub ? 3 : 2);1787    ExtValue V = MI.getOperand(IsSub ? 2 : 3);1788    assert(EV == V && Rs == Ex.Rs && IsSub == Ex.Neg && "Initializer mismatch");1789#endif1790    unsigned NewOpc = ExtOpc == Hexagon::M2_naccii ? Hexagon::A2_sub1791                                                   : Hexagon::A2_add;1792    BuildMI(MBB, At, dl, HII->get(NewOpc))1793      .add(MI.getOperand(0))1794      .add(MI.getOperand(1))1795      .add(MachineOperand(ExtR));1796    MBB.erase(MI);1797    return true;1798  }1799 1800  if (MI.mayLoadOrStore()) {1801    unsigned IdxOpc = getRegOffOpcode(ExtOpc);1802    assert(IdxOpc && "Expecting indexed opcode");1803    MachineInstrBuilder MIB = BuildMI(MBB, At, dl, HII->get(IdxOpc));1804    // Construct the new indexed instruction.1805    // First, add the def for loads.1806    if (MI.mayLoad())1807      MIB.add(getLoadResultOp(MI));1808    // Handle possible predication.1809    if (HII->isPredicated(MI))1810      MIB.add(getPredicateOp(MI));1811    // Build the address.1812    MIB.add(MachineOperand(ExtR));1813    MIB.addImm(Diff);1814    // Add the stored value for stores.1815    if (MI.mayStore())1816      MIB.add(getStoredValueOp(MI));1817    MIB.cloneMemRefs(MI);1818    MBB.erase(MI);1819    return true;1820  }1821 1822#ifndef NDEBUG1823  dbgs() << '\n' << PrintInit(ExtI, *HRI) << "  " << MI;1824#endif1825  llvm_unreachable("Unhandled expr replacement");1826  return false;1827}1828 1829bool HCE::replaceInstr(unsigned Idx, Register ExtR, const ExtenderInit &ExtI) {1830  if (ReplaceLimit.getNumOccurrences()) {1831    if (ReplaceLimit <= ReplaceCounter)1832      return false;1833    ++ReplaceCounter;1834  }1835  const ExtDesc &ED = Extenders[Idx];1836  assert((!ED.IsDef || ED.Rd.Reg != 0) && "Missing Rd for def");1837  const ExtValue &DefV = ExtI.first;1838  assert(ExtRoot(ExtValue(ED)) == ExtRoot(DefV) && "Extender root mismatch");1839  const ExtExpr &DefEx = ExtI.second;1840 1841  ExtValue EV(ED);1842  int32_t Diff = EV.Offset - DefV.Offset;1843  const MachineInstr &MI = *ED.UseMI;1844  LLVM_DEBUG(dbgs() << __func__ << " Idx:" << Idx << " ExtR:"1845                    << PrintRegister(ExtR, *HRI) << " Diff:" << Diff << '\n');1846 1847  // These two addressing modes must be converted into indexed forms1848  // regardless of what the initializer looks like.1849  bool IsAbs = false, IsAbsSet = false;1850  if (MI.mayLoadOrStore()) {1851    unsigned AM = HII->getAddrMode(MI);1852    IsAbs = AM == HexagonII::Absolute;1853    IsAbsSet = AM == HexagonII::AbsoluteSet;1854  }1855 1856  // If it's a def, remember all operands that need to be updated.1857  // If ED is a def, and Diff is not 0, then all uses of the register Rd1858  // defined by ED must be in the form (Rd, imm), i.e. the immediate offset1859  // must follow the Rd in the operand list.1860  std::vector<std::pair<MachineInstr*,unsigned>> RegOps;1861  if (ED.IsDef && Diff != 0) {1862    for (MachineOperand &Op : MRI->use_operands(ED.Rd.Reg)) {1863      MachineInstr &UI = *Op.getParent();1864      RegOps.push_back({&UI, getOperandIndex(UI, Op)});1865    }1866  }1867 1868  // Replace the instruction.1869  bool Replaced = false;1870  if (Diff == 0 && DefEx.trivial() && !IsAbs && !IsAbsSet)1871    Replaced = replaceInstrExact(ED, ExtR);1872  else1873    Replaced = replaceInstrExpr(ED, ExtI, ExtR, Diff);1874 1875  if (Diff != 0 && Replaced && ED.IsDef) {1876    // Update offsets of the def's uses.1877    for (std::pair<MachineInstr*,unsigned> P : RegOps) {1878      unsigned J = P.second;1879      assert(P.first->getNumOperands() > J+1 &&1880             P.first->getOperand(J+1).isImm());1881      MachineOperand &ImmOp = P.first->getOperand(J+1);1882      ImmOp.setImm(ImmOp.getImm() + Diff);1883    }1884    // If it was an absolute-set instruction, the "set" part has been removed.1885    // ExtR will now be the register with the extended value, and since all1886    // users of Rd have been updated, all that needs to be done is to replace1887    // Rd with ExtR.1888    if (IsAbsSet) {1889      assert(ED.Rd.Sub == 0 && ExtR.Sub == 0);1890      MRI->replaceRegWith(ED.Rd.Reg, ExtR.Reg);1891    }1892  }1893 1894  return Replaced;1895}1896 1897bool HCE::replaceExtenders(const AssignmentMap &IMap) {1898  LocDefList Defs;1899  bool Changed = false;1900 1901  for (const std::pair<const ExtenderInit, IndexList> &P : IMap) {1902    const IndexList &Idxs = P.second;1903    if (Idxs.size() < CountThreshold)1904      continue;1905 1906    Defs.clear();1907    calculatePlacement(P.first, Idxs, Defs);1908    for (const std::pair<Loc,IndexList> &Q : Defs) {1909      Register DefR = insertInitializer(Q.first, P.first);1910      NewRegs.push_back(DefR.Reg);1911      for (unsigned I : Q.second)1912        Changed |= replaceInstr(I, DefR, P.first);1913    }1914  }1915  return Changed;1916}1917 1918unsigned HCE::getOperandIndex(const MachineInstr &MI,1919      const MachineOperand &Op) const {1920  for (unsigned i = 0, n = MI.getNumOperands(); i != n; ++i)1921    if (&MI.getOperand(i) == &Op)1922      return i;1923  llvm_unreachable("Not an operand of MI");1924}1925 1926const MachineOperand &HCE::getPredicateOp(const MachineInstr &MI) const {1927  assert(HII->isPredicated(MI));1928  for (const MachineOperand &Op : MI.operands()) {1929    if (!Op.isReg() || !Op.isUse() ||1930        MRI->getRegClass(Op.getReg()) != &Hexagon::PredRegsRegClass)1931      continue;1932    assert(Op.getSubReg() == 0 && "Predicate register with a subregister");1933    return Op;1934  }1935  llvm_unreachable("Predicate operand not found");1936}1937 1938const MachineOperand &HCE::getLoadResultOp(const MachineInstr &MI) const {1939  assert(MI.mayLoad());1940  return MI.getOperand(0);1941}1942 1943const MachineOperand &HCE::getStoredValueOp(const MachineInstr &MI) const {1944  assert(MI.mayStore());1945  return MI.getOperand(MI.getNumExplicitOperands()-1);1946}1947 1948bool HCE::runOnMachineFunction(MachineFunction &MF) {1949  if (skipFunction(MF.getFunction()))1950    return false;1951  if (MF.getFunction().hasPersonalityFn()) {1952    LLVM_DEBUG(dbgs() << getPassName() << ": skipping " << MF.getName()1953                      << " due to exception handling\n");1954    return false;1955  }1956  LLVM_DEBUG(MF.print(dbgs() << "Before " << getPassName() << '\n', nullptr));1957 1958  HST = &MF.getSubtarget<HexagonSubtarget>();1959  HII = HST->getInstrInfo();1960  HRI = HST->getRegisterInfo();1961  MDT = &getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();1962  MRI = &MF.getRegInfo();1963  AssignmentMap IMap;1964 1965  collect(MF);1966  llvm::sort(Extenders, [this](const ExtDesc &A, const ExtDesc &B) {1967    ExtValue VA(A), VB(B);1968    if (VA != VB)1969      return VA < VB;1970    const MachineInstr *MA = A.UseMI;1971    const MachineInstr *MB = B.UseMI;1972    if (MA == MB) {1973      // If it's the same instruction, compare operand numbers.1974      return A.OpNum < B.OpNum;1975    }1976 1977    const MachineBasicBlock *BA = MA->getParent();1978    const MachineBasicBlock *BB = MB->getParent();1979    assert(BA->getNumber() != -1 && BB->getNumber() != -1);1980    if (BA != BB)1981      return BA->getNumber() < BB->getNumber();1982    return MDT->dominates(MA, MB);1983  });1984 1985  bool Changed = false;1986  LLVM_DEBUG(dbgs() << "Collected " << Extenders.size() << " extenders\n");1987  for (unsigned I = 0, E = Extenders.size(); I != E; ) {1988    unsigned B = I;1989    const ExtRoot &T = Extenders[B].getOp();1990    while (I != E && ExtRoot(Extenders[I].getOp()) == T)1991      ++I;1992 1993    IMap.clear();1994    assignInits(T, B, I, IMap);1995    Changed |= replaceExtenders(IMap);1996  }1997 1998  LLVM_DEBUG({1999    if (Changed)2000      MF.print(dbgs() << "After " << getPassName() << '\n', nullptr);2001    else2002      dbgs() << "No changes\n";2003  });2004  return Changed;2005}2006 2007FunctionPass *llvm::createHexagonConstExtenders() {2008  return new HexagonConstExtenders();2009}2010