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1//===-------- CompressInstEmitter.cpp - Generator for Compression ---------===//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// CompressInstEmitter implements a tablegen-driven CompressPat based8// Instruction Compression mechanism.9//10//===----------------------------------------------------------------------===//11//12// CompressInstEmitter implements a tablegen-driven CompressPat Instruction13// Compression mechanism for generating compressed instructions from the14// expanded instruction form.15 16// This tablegen backend processes CompressPat declarations in a17// td file and generates all the required checks to validate the pattern18// declarations; validate the input and output operands to generate the correct19// compressed instructions. The checks include validating different types of20// operands; register operands, immediate operands, fixed register and fixed21// immediate inputs.22//23// Example:24// /// Defines a Pat match between compressed and uncompressed instruction.25// /// The relationship and helper function generation are handled by26// /// CompressInstEmitter backend.27// class CompressPat<dag input, dag output, list<Predicate> predicates = []> {28//   /// Uncompressed instruction description.29//   dag Input = input;30//   /// Compressed instruction description.31//   dag Output = output;32//   /// Predicates that must be true for this to match.33//   list<Predicate> Predicates = predicates;34//   /// Duplicate match when tied operand is just different.35//   bit isCompressOnly = false;36// }37//38// let Predicates = [HasStdExtC] in {39// def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs1, GPRNoX0:$rs2),40//                   (C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>;41// }42//43// The <TargetName>GenCompressInstEmitter.inc is an auto-generated header44// file which exports two functions for compressing/uncompressing MCInst45// instructions, plus some helper functions:46//47// bool compressInst(MCInst &OutInst, const MCInst &MI,48//                   const MCSubtargetInfo &STI);49//50// bool uncompressInst(MCInst &OutInst, const MCInst &MI,51//                     const MCSubtargetInfo &STI);52//53// In addition, it exports a function for checking whether54// an instruction is compressable:55//56// bool isCompressibleInst(const MachineInstr& MI,57//                         const <TargetName>Subtarget &STI);58//59// The clients that include this auto-generated header file and60// invoke these functions can compress an instruction before emitting61// it in the target-specific ASM or ELF streamer or can uncompress62// an instruction before printing it when the expanded instruction63// format aliases is favored.64 65//===----------------------------------------------------------------------===//66 67#include "Common/CodeGenInstruction.h"68#include "Common/CodeGenRegisters.h"69#include "Common/CodeGenTarget.h"70#include "llvm/ADT/IndexedMap.h"71#include "llvm/ADT/SmallVector.h"72#include "llvm/ADT/StringMap.h"73#include "llvm/Support/Debug.h"74#include "llvm/Support/ErrorHandling.h"75#include "llvm/TableGen/Error.h"76#include "llvm/TableGen/Record.h"77#include "llvm/TableGen/TableGenBackend.h"78#include <limits>79#include <set>80#include <vector>81using namespace llvm;82 83#define DEBUG_TYPE "compress-inst-emitter"84 85namespace {86class CompressInstEmitter {87  struct OpData {88    enum MapKind { Operand, Imm, Reg } Kind;89    // Info for an operand.90    struct OpndInfo {91      // Record from the Dag.92      const Record *DagRec;93      // Operand number mapped to.94      unsigned Idx;95      // Tied operand index within the instruction.96      int TiedOpIdx;97    };98    union {99      OpndInfo OpInfo;100      // Integer immediate value.101      int64_t ImmVal;102      // Physical register.103      const Record *RegRec;104    };105  };106  struct ArgData {107    unsigned DAGOpNo;108    unsigned MIOpNo;109  };110  struct CompressPat {111    // The source instruction definition.112    CodeGenInstruction Source;113    // The destination instruction to transform to.114    CodeGenInstruction Dest;115    // Required target features to enable pattern.116    std::vector<const Record *> PatReqFeatures;117    // Maps operands in the Source Instruction to118    // the corresponding Dest instruction operand.119    IndexedMap<OpData> SourceOperandMap;120    // Maps operands in the Dest Instruction121    // to the corresponding Source instruction operand.122    IndexedMap<OpData> DestOperandMap;123 124    bool IsCompressOnly;125    CompressPat(const CodeGenInstruction &S, const CodeGenInstruction &D,126                std::vector<const Record *> RF,127                const IndexedMap<OpData> &SourceMap,128                const IndexedMap<OpData> &DestMap, bool IsCompressOnly)129        : Source(S), Dest(D), PatReqFeatures(std::move(RF)),130          SourceOperandMap(SourceMap), DestOperandMap(DestMap),131          IsCompressOnly(IsCompressOnly) {}132  };133  enum EmitterType { Compress, Uncompress, CheckCompress };134  const RecordKeeper &Records;135  const CodeGenTarget Target;136  std::vector<CompressPat> CompressPatterns;137  void addDagOperandMapping(const Record *Rec, const DagInit *Dag,138                            const CodeGenInstruction &Inst,139                            IndexedMap<OpData> &OperandMap,140                            StringMap<ArgData> &Operands, bool IsSourceInst);141  void evaluateCompressPat(const Record *Compress);142  void emitCompressInstEmitter(raw_ostream &OS, EmitterType EType);143  bool validateTypes(const Record *DagOpType, const Record *InstOpType,144                     bool IsSourceInst);145  bool validateRegister(const Record *Reg, const Record *RegClass);146  void checkDagOperandMapping(const Record *Rec,147                              const StringMap<ArgData> &DestOperands,148                              const DagInit *SourceDag, const DagInit *DestDag);149 150  void createInstOperandMapping(const Record *Rec, const DagInit *SourceDag,151                                const DagInit *DestDag,152                                IndexedMap<OpData> &SourceOperandMap,153                                IndexedMap<OpData> &DestOperandMap,154                                StringMap<ArgData> &SourceOperands,155                                const CodeGenInstruction &DestInst);156 157public:158  CompressInstEmitter(const RecordKeeper &R) : Records(R), Target(R) {}159 160  void run(raw_ostream &OS);161};162} // End anonymous namespace.163 164bool CompressInstEmitter::validateRegister(const Record *Reg,165                                           const Record *RegClass) {166  assert(Reg->isSubClassOf("Register") && "Reg record should be a Register");167  assert(RegClass->isSubClassOf("RegisterClass") &&168         "RegClass record should be a RegisterClass");169  const CodeGenRegisterClass &RC = Target.getRegisterClass(RegClass);170  const CodeGenRegister *R = Target.getRegBank().getReg(Reg);171  assert(R != nullptr && "Register not defined!!");172  return RC.contains(R);173}174 175bool CompressInstEmitter::validateTypes(const Record *DagOpType,176                                        const Record *InstOpType,177                                        bool IsSourceInst) {178  if (DagOpType == InstOpType)179    return true;180 181  if (DagOpType->isSubClassOf("RegisterClass") &&182      InstOpType->isSubClassOf("RegisterClass")) {183    const CodeGenRegisterClass &RC = Target.getRegisterClass(InstOpType);184    const CodeGenRegisterClass &SubRC = Target.getRegisterClass(DagOpType);185    return RC.hasSubClass(&SubRC);186  }187 188  // At this point either or both types are not registers, reject the pattern.189  if (DagOpType->isSubClassOf("RegisterClass") ||190      InstOpType->isSubClassOf("RegisterClass"))191    return false;192 193  // Let further validation happen when compress()/uncompress() functions are194  // invoked.195  LLVM_DEBUG(dbgs() << (IsSourceInst ? "Input" : "Output")196                    << " Dag Operand Type: '" << DagOpType->getName()197                    << "' and "198                    << "Instruction Operand Type: '" << InstOpType->getName()199                    << "' can't be checked at pattern validation time!\n");200  return true;201}202 203static bool validateArgsTypes(const Init *Arg1, const Init *Arg2) {204  return cast<DefInit>(Arg1)->getDef() == cast<DefInit>(Arg2)->getDef();205}206 207/// The patterns in the Dag contain different types of operands:208/// Register operands, e.g.: GPRC:$rs1; Fixed registers, e.g: X1; Immediate209/// operands, e.g.: simm6:$imm; Fixed immediate operands, e.g.: 0. This function210/// maps Dag operands to its corresponding instruction operands. For register211/// operands and fixed registers it expects the Dag operand type to be contained212/// in the instantiated instruction operand type. For immediate operands and213/// immediates no validation checks are enforced at pattern validation time.214void CompressInstEmitter::addDagOperandMapping(const Record *Rec,215                                               const DagInit *Dag,216                                               const CodeGenInstruction &Inst,217                                               IndexedMap<OpData> &OperandMap,218                                               StringMap<ArgData> &Operands,219                                               bool IsSourceInst) {220  unsigned NumMIOperands = 0;221  if (!Inst.Operands.empty())222    NumMIOperands =223        Inst.Operands.back().MIOperandNo + Inst.Operands.back().MINumOperands;224  OperandMap.grow(NumMIOperands);225 226  // Tied operands are not represented in the DAG so we count them separately.227  unsigned DAGOpNo = 0;228  unsigned OpNo = 0;229  for (const auto &Opnd : Inst.Operands) {230    int TiedOpIdx = Opnd.getTiedRegister();231    if (-1 != TiedOpIdx) {232      assert((unsigned)TiedOpIdx < OpNo);233      // Set the entry in OperandMap for the tied operand we're skipping.234      OperandMap[OpNo] = OperandMap[TiedOpIdx];235      ++OpNo;236 237      // Source instructions can have at most 1 tied operand.238      if (IsSourceInst && (OpNo - DAGOpNo > 1))239        PrintFatalError(Rec->getLoc(),240                        "Input operands for Inst '" + Inst.getName() +241                            "' and input Dag operand count mismatch");242 243      continue;244    }245    for (unsigned SubOp = 0; SubOp != Opnd.MINumOperands;246         ++SubOp, ++OpNo, ++DAGOpNo) {247      const Record *OpndRec = Opnd.Rec;248      if (Opnd.MINumOperands > 1)249        OpndRec = cast<DefInit>(Opnd.MIOperandInfo->getArg(SubOp))->getDef();250 251      if (DAGOpNo >= Dag->getNumArgs())252        PrintFatalError(Rec->getLoc(), "Inst '" + Inst.getName() +253                                           "' and Dag operand count mismatch");254 255      if (const auto *DI = dyn_cast<DefInit>(Dag->getArg(DAGOpNo))) {256        if (DI->getDef()->isSubClassOf("Register")) {257          // Check if the fixed register belongs to the Register class.258          if (!validateRegister(DI->getDef(), OpndRec))259            PrintFatalError(Rec->getLoc(),260                            "Error in Dag '" + Dag->getAsString() +261                                "'Register: '" + DI->getDef()->getName() +262                                "' is not in register class '" +263                                OpndRec->getName() + "'");264          OperandMap[OpNo].Kind = OpData::Reg;265          OperandMap[OpNo].RegRec = DI->getDef();266          continue;267        }268        // Validate that Dag operand type matches the type defined in the269        // corresponding instruction. Operands in the input and output Dag270        // patterns are allowed to be a subclass of the type specified in the271        // corresponding instruction operand instead of being an exact match.272        if (!validateTypes(DI->getDef(), OpndRec, IsSourceInst))273          PrintFatalError(Rec->getLoc(),274                          "Error in Dag '" + Dag->getAsString() +275                              "'. Operand '" + Dag->getArgNameStr(DAGOpNo) +276                              "' has type '" + DI->getDef()->getName() +277                              "' which does not match the type '" +278                              OpndRec->getName() +279                              "' in the corresponding instruction operand!");280 281        OperandMap[OpNo].Kind = OpData::Operand;282        OperandMap[OpNo].OpInfo.DagRec = DI->getDef();283        OperandMap[OpNo].OpInfo.TiedOpIdx = -1;284 285        // Create a mapping between the operand name in the Dag (e.g. $rs1) and286        // its index in the list of Dag operands and check that operands with287        // the same name have the same type. For example in 'C_ADD $rs1, $rs2'288        // we generate the mapping $rs1 --> 0, $rs2 ---> 1. If the operand289        // appears twice in the same Dag (tied in the compressed instruction),290        // we note the previous index in the TiedOpIdx field.291        StringRef ArgName = Dag->getArgNameStr(DAGOpNo);292        if (ArgName.empty())293          continue;294 295        if (IsSourceInst) {296          auto It = Operands.find(ArgName);297          if (It != Operands.end()) {298            OperandMap[OpNo].OpInfo.TiedOpIdx = It->getValue().MIOpNo;299            if (OperandMap[It->getValue().MIOpNo].OpInfo.DagRec != DI->getDef())300              PrintFatalError(Rec->getLoc(),301                              "Input Operand '" + ArgName +302                                  "' has a mismatched tied operand!");303          }304        }305 306        Operands[ArgName] = {DAGOpNo, OpNo};307      } else if (const auto *II = dyn_cast<IntInit>(Dag->getArg(DAGOpNo))) {308        // Validate that corresponding instruction operand expects an immediate.309        if (!OpndRec->isSubClassOf("Operand"))310          PrintFatalError(Rec->getLoc(), "Error in Dag '" + Dag->getAsString() +311                                             "' Found immediate: '" +312                                             II->getAsString() +313                                             "' but corresponding instruction "314                                             "operand expected a register!");315        // No pattern validation check possible for values of fixed immediate.316        OperandMap[OpNo].Kind = OpData::Imm;317        OperandMap[OpNo].ImmVal = II->getValue();318        LLVM_DEBUG(319            dbgs() << "  Found immediate '" << II->getValue() << "' at "320                   << (IsSourceInst ? "input " : "output ")321                   << "Dag. No validation time check possible for values of "322                      "fixed immediate.\n");323      } else {324        llvm_unreachable("Unhandled CompressPat argument type!");325      }326    }327  }328 329  // We shouldn't have extra Dag operands.330  if (DAGOpNo != Dag->getNumArgs())331    PrintFatalError(Rec->getLoc(), "Inst '" + Inst.getName() +332                                       "' and Dag operand count mismatch");333}334 335// Check that all names in the source DAG appear in the destionation DAG.336void CompressInstEmitter::checkDagOperandMapping(337    const Record *Rec, const StringMap<ArgData> &DestOperands,338    const DagInit *SourceDag, const DagInit *DestDag) {339 340  for (unsigned I = 0; I < SourceDag->getNumArgs(); ++I) {341    // Skip fixed immediates and registers, they were handled in342    // addDagOperandMapping.343    StringRef ArgName = SourceDag->getArgNameStr(I);344    if (ArgName.empty())345      continue;346 347    auto It = DestOperands.find(ArgName);348    if (It == DestOperands.end())349      PrintFatalError(Rec->getLoc(), "Operand " + ArgName +350                                         " defined in Input Dag but not used in"351                                         " Output Dag!");352    // Input Dag operand types must match output Dag operand type.353    if (!validateArgsTypes(DestDag->getArg(It->getValue().DAGOpNo),354                           SourceDag->getArg(I)))355      PrintFatalError(Rec->getLoc(), "Type mismatch between Input and "356                                     "Output Dag operand '" +357                                         ArgName + "'!");358  }359}360 361/// Map operand names in the Dag to their index in both corresponding input and362/// output instructions. Validate that operands defined in the input are363/// used in the output pattern while populating the maps.364void CompressInstEmitter::createInstOperandMapping(365    const Record *Rec, const DagInit *SourceDag, const DagInit *DestDag,366    IndexedMap<OpData> &SourceOperandMap, IndexedMap<OpData> &DestOperandMap,367    StringMap<ArgData> &SourceOperands, const CodeGenInstruction &DestInst) {368  // TiedCount keeps track of the number of operands skipped in Inst369  // operands list to get to the corresponding Dag operand.370  unsigned TiedCount = 0;371  LLVM_DEBUG(dbgs() << "  Operand mapping:\n  Source   Dest\n");372  unsigned OpNo = 0;373  for (const auto &Operand : DestInst.Operands) {374    int TiedInstOpIdx = Operand.getTiedRegister();375    if (TiedInstOpIdx != -1) {376      ++TiedCount;377      assert((unsigned)TiedInstOpIdx < OpNo);378      DestOperandMap[OpNo] = DestOperandMap[TiedInstOpIdx];379      if (DestOperandMap[OpNo].Kind == OpData::Operand)380        // No need to fill the SourceOperandMap here since it was mapped to381        // destination operand 'TiedInstOpIdx' in a previous iteration.382        LLVM_DEBUG(dbgs() << "    " << DestOperandMap[OpNo].OpInfo.Idx383                          << " ====> " << OpNo384                          << "  Dest operand tied with operand '"385                          << TiedInstOpIdx << "'\n");386      ++OpNo;387      continue;388    }389 390    for (unsigned SubOp = 0; SubOp != Operand.MINumOperands; ++SubOp, ++OpNo) {391      // Skip fixed immediates and registers, they were handled in392      // addDagOperandMapping.393      if (DestOperandMap[OpNo].Kind != OpData::Operand)394        continue;395 396      unsigned DagArgIdx = OpNo - TiedCount;397      StringRef ArgName = DestDag->getArgNameStr(DagArgIdx);398      auto SourceOp = SourceOperands.find(ArgName);399      if (SourceOp == SourceOperands.end())400        PrintFatalError(Rec->getLoc(),401                        "Output Dag operand '" + ArgName +402                            "' has no matching input Dag operand.");403 404      assert(ArgName ==405                 SourceDag->getArgNameStr(SourceOp->getValue().DAGOpNo) &&406             "Incorrect operand mapping detected!\n");407 408      unsigned SourceOpNo = SourceOp->getValue().MIOpNo;409      DestOperandMap[OpNo].OpInfo.Idx = SourceOpNo;410      SourceOperandMap[SourceOpNo].OpInfo.Idx = OpNo;411      LLVM_DEBUG(dbgs() << "    " << SourceOpNo << " ====> " << OpNo << "\n");412    }413  }414}415 416/// Validates the CompressPattern and create operand mapping.417/// These are the checks to validate a CompressPat pattern declarations.418/// Error out with message under these conditions:419/// - Dag Input opcode is an expanded instruction and Dag Output opcode is a420///   compressed instruction.421/// - Operands in Dag Input must be all used in Dag Output.422///   Register Operand type in Dag Input Type must be contained in the423///   corresponding Source Instruction type.424/// - Register Operand type in Dag Input must be the same as in Dag Ouput.425/// - Register Operand type in Dag Output must be the same as the426///   corresponding Destination Inst type.427/// - Immediate Operand type in Dag Input must be the same as in Dag Ouput.428/// - Immediate Operand type in Dag Ouput must be the same as the corresponding429///   Destination Instruction type.430/// - Fixed register must be contained in the corresponding Source Instruction431///   type.432/// - Fixed register must be contained in the corresponding Destination433///   Instruction type.434/// Warning message printed under these conditions:435/// - Fixed immediate in Dag Input or Dag Ouput cannot be checked at this time436///   and generate warning.437/// - Immediate operand type in Dag Input differs from the corresponding Source438///   Instruction type and generate a warning.439void CompressInstEmitter::evaluateCompressPat(const Record *Rec) {440  // Validate input Dag operands.441  const DagInit *SourceDag = Rec->getValueAsDag("Input");442  assert(SourceDag && "Missing 'Input' in compress pattern!");443  LLVM_DEBUG(dbgs() << "Input: " << *SourceDag << "\n");444 445  // Checking we are transforming from compressed to uncompressed instructions.446  const Record *SourceOperator = SourceDag->getOperatorAsDef(Rec->getLoc());447  CodeGenInstruction SourceInst(SourceOperator);448 449  // Validate output Dag operands.450  const DagInit *DestDag = Rec->getValueAsDag("Output");451  assert(DestDag && "Missing 'Output' in compress pattern!");452  LLVM_DEBUG(dbgs() << "Output: " << *DestDag << "\n");453 454  const Record *DestOperator = DestDag->getOperatorAsDef(Rec->getLoc());455  CodeGenInstruction DestInst(DestOperator);456 457  if (SourceOperator->getValueAsInt("Size") <=458      DestOperator->getValueAsInt("Size"))459    PrintFatalError(460        Rec->getLoc(),461        "Compressed instruction '" + DestOperator->getName() +462            "'is not strictly smaller than the uncompressed instruction '" +463            SourceOperator->getName() + "' !");464 465  // Fill the mapping from the source to destination instructions.466 467  IndexedMap<OpData> SourceOperandMap;468  // Map from arg name to DAG operand number and MI operand number.469  StringMap<ArgData> SourceOperands;470  // Create a mapping between source Dag operands and source Inst operands.471  addDagOperandMapping(Rec, SourceDag, SourceInst, SourceOperandMap,472                       SourceOperands, /*IsSourceInst*/ true);473 474  IndexedMap<OpData> DestOperandMap;475  // Map from arg name to DAG operand number and MI operand number.476  StringMap<ArgData> DestOperands;477  // Create a mapping between destination Dag operands and destination Inst478  // operands.479  addDagOperandMapping(Rec, DestDag, DestInst, DestOperandMap, DestOperands,480                       /*IsSourceInst*/ false);481 482  checkDagOperandMapping(Rec, DestOperands, SourceDag, DestDag);483  // Create operand mapping between the source and destination instructions.484  createInstOperandMapping(Rec, SourceDag, DestDag, SourceOperandMap,485                           DestOperandMap, SourceOperands, DestInst);486 487  // Get the target features for the CompressPat.488  std::vector<const Record *> PatReqFeatures;489  std::vector<const Record *> RF = Rec->getValueAsListOfDefs("Predicates");490  copy_if(RF, std::back_inserter(PatReqFeatures), [](const Record *R) {491    return R->getValueAsBit("AssemblerMatcherPredicate");492  });493 494  CompressPatterns.emplace_back(SourceInst, DestInst, std::move(PatReqFeatures),495                                SourceOperandMap, DestOperandMap,496                                Rec->getValueAsBit("isCompressOnly"));497}498 499static void500getReqFeatures(std::set<std::pair<bool, StringRef>> &FeaturesSet,501               std::set<std::set<std::pair<bool, StringRef>>> &AnyOfFeatureSets,502               ArrayRef<const Record *> ReqFeatures) {503  for (const Record *R : ReqFeatures) {504    const DagInit *D = R->getValueAsDag("AssemblerCondDag");505    std::string CombineType = D->getOperator()->getAsString();506    if (CombineType != "any_of" && CombineType != "all_of")507      PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");508    if (D->getNumArgs() == 0)509      PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");510    bool IsOr = CombineType == "any_of";511    std::set<std::pair<bool, StringRef>> AnyOfSet;512 513    for (auto *Arg : D->getArgs()) {514      bool IsNot = false;515      if (auto *NotArg = dyn_cast<DagInit>(Arg)) {516        if (NotArg->getOperator()->getAsString() != "not" ||517            NotArg->getNumArgs() != 1)518          PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");519        Arg = NotArg->getArg(0);520        IsNot = true;521      }522      if (!isa<DefInit>(Arg) ||523          !cast<DefInit>(Arg)->getDef()->isSubClassOf("SubtargetFeature"))524        PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");525      if (IsOr)526        AnyOfSet.emplace(IsNot, cast<DefInit>(Arg)->getDef()->getName());527      else528        FeaturesSet.emplace(IsNot, cast<DefInit>(Arg)->getDef()->getName());529    }530 531    if (IsOr)532      AnyOfFeatureSets.insert(std::move(AnyOfSet));533  }534}535 536static unsigned getPredicates(DenseMap<const Record *, unsigned> &PredicateMap,537                              std::vector<const Record *> &Predicates,538                              const Record *Rec, StringRef Name) {539  unsigned &Entry = PredicateMap[Rec];540  if (Entry)541    return Entry;542 543  if (!Rec->isValueUnset(Name)) {544    Predicates.push_back(Rec);545    Entry = Predicates.size();546    return Entry;547  }548 549  PrintFatalError(Rec->getLoc(), "No " + Name +550                                     " predicate on this operand at all: '" +551                                     Rec->getName() + "'");552  return 0;553}554 555static void printPredicates(ArrayRef<const Record *> Predicates, StringRef Name,556                            raw_ostream &OS) {557  for (unsigned I = 0; I < Predicates.size(); ++I) {558    StringRef Pred = Predicates[I]->getValueAsString(Name);559    Pred = Pred.trim();560    OS.indent(2) << "case " << I + 1 << ": {\n";561    OS.indent(4) << "// " << Predicates[I]->getName() << "\n";562    OS.indent(4) << Pred << "\n";563    OS.indent(2) << "}\n";564  }565}566 567static void mergeCondAndCode(raw_ostream &CombinedStream, StringRef CondStr,568                             StringRef CodeStr) {569  CombinedStream.indent(4) << "if (" << CondStr << ") {\n";570  CombinedStream << CodeStr;571  CombinedStream.indent(4) << "  return true;\n";572  CombinedStream.indent(4) << "} // if\n";573}574 575void CompressInstEmitter::emitCompressInstEmitter(raw_ostream &OS,576                                                  EmitterType EType) {577  const Record *AsmWriter = Target.getAsmWriter();578  if (!AsmWriter->getValueAsInt("PassSubtarget"))579    PrintFatalError(AsmWriter->getLoc(),580                    "'PassSubtarget' is false. SubTargetInfo object is needed "581                    "for target features.");582 583  StringRef TargetName = Target.getName();584 585  // Sort entries in CompressPatterns to handle instructions that can have more586  // than one candidate for compression\uncompression, e.g ADD can be587  // transformed to a C_ADD or a C_MV. When emitting 'uncompress()' function the588  // source and destination are flipped and the sort key needs to change589  // accordingly.590  llvm::stable_sort(CompressPatterns, [EType](const CompressPat &LHS,591                                              const CompressPat &RHS) {592    if (EType == EmitterType::Compress || EType == EmitterType::CheckCompress)593      return LHS.Source.getName() < RHS.Source.getName();594    return LHS.Dest.getName() < RHS.Dest.getName();595  });596 597  // A list of MCOperandPredicates for all operands in use, and the reverse map.598  std::vector<const Record *> MCOpPredicates;599  DenseMap<const Record *, unsigned> MCOpPredicateMap;600  // A list of ImmLeaf Predicates for all operands in use, and the reverse map.601  std::vector<const Record *> ImmLeafPredicates;602  DenseMap<const Record *, unsigned> ImmLeafPredicateMap;603 604  std::string F;605  std::string FH;606  raw_string_ostream Func(F);607  raw_string_ostream FuncH(FH);608 609  if (EType == EmitterType::Compress)610    OS << "\n#ifdef GEN_COMPRESS_INSTR\n"611       << "#undef GEN_COMPRESS_INSTR\n\n";612  else if (EType == EmitterType::Uncompress)613    OS << "\n#ifdef GEN_UNCOMPRESS_INSTR\n"614       << "#undef GEN_UNCOMPRESS_INSTR\n\n";615  else if (EType == EmitterType::CheckCompress)616    OS << "\n#ifdef GEN_CHECK_COMPRESS_INSTR\n"617       << "#undef GEN_CHECK_COMPRESS_INSTR\n\n";618 619  if (EType == EmitterType::Compress) {620    FuncH << "static bool compressInst(MCInst &OutInst,\n";621    FuncH.indent(25) << "const MCInst &MI,\n";622    FuncH.indent(25) << "const MCSubtargetInfo &STI) {\n";623  } else if (EType == EmitterType::Uncompress) {624    FuncH << "static bool uncompressInst(MCInst &OutInst,\n";625    FuncH.indent(27) << "const MCInst &MI,\n";626    FuncH.indent(27) << "const MCSubtargetInfo &STI) {\n";627  } else if (EType == EmitterType::CheckCompress) {628    FuncH << "static bool isCompressibleInst(const MachineInstr &MI,\n";629    FuncH.indent(31) << "const " << TargetName << "Subtarget &STI) {\n";630  }631 632  if (CompressPatterns.empty()) {633    OS << FH;634    OS.indent(2) << "return false;\n}\n";635    if (EType == EmitterType::Compress)636      OS << "\n#endif //GEN_COMPRESS_INSTR\n";637    else if (EType == EmitterType::Uncompress)638      OS << "\n#endif //GEN_UNCOMPRESS_INSTR\n\n";639    else if (EType == EmitterType::CheckCompress)640      OS << "\n#endif //GEN_CHECK_COMPRESS_INSTR\n\n";641    return;642  }643 644  std::string CaseString;645  raw_string_ostream CaseStream(CaseString);646  StringRef PrevOp;647  StringRef CurOp;648  CaseStream << "  switch (MI.getOpcode()) {\n";649  CaseStream << "  default: return false;\n";650 651  bool CompressOrCheck =652      EType == EmitterType::Compress || EType == EmitterType::CheckCompress;653  bool CompressOrUncompress =654      EType == EmitterType::Compress || EType == EmitterType::Uncompress;655  std::string ValidatorName =656      CompressOrUncompress657          ? (TargetName + "ValidateMCOperandFor" +658             (EType == EmitterType::Compress ? "Compress" : "Uncompress"))659                .str()660          : "";661 662  for (const auto &CompressPat : CompressPatterns) {663    if (EType == EmitterType::Uncompress && CompressPat.IsCompressOnly)664      continue;665 666    std::string CondString;667    std::string CodeString;668    raw_string_ostream CondStream(CondString);669    raw_string_ostream CodeStream(CodeString);670    const CodeGenInstruction &Source =671        CompressOrCheck ? CompressPat.Source : CompressPat.Dest;672    const CodeGenInstruction &Dest =673        CompressOrCheck ? CompressPat.Dest : CompressPat.Source;674    const IndexedMap<OpData> &SourceOperandMap =675        CompressOrCheck ? CompressPat.SourceOperandMap676                        : CompressPat.DestOperandMap;677    const IndexedMap<OpData> &DestOperandMap =678        CompressOrCheck ? CompressPat.DestOperandMap679                        : CompressPat.SourceOperandMap;680 681    CurOp = Source.getName();682    // Check current and previous opcode to decide to continue or end a case.683    if (CurOp != PrevOp) {684      if (!PrevOp.empty()) {685        CaseStream.indent(4) << "break;\n";686        CaseStream.indent(2) << "} // case " + PrevOp + "\n";687      }688      CaseStream.indent(2) << "case " + TargetName + "::" + CurOp + ": {\n";689    }690 691    std::set<std::pair<bool, StringRef>> FeaturesSet;692    std::set<std::set<std::pair<bool, StringRef>>> AnyOfFeatureSets;693    // Add CompressPat required features.694    getReqFeatures(FeaturesSet, AnyOfFeatureSets, CompressPat.PatReqFeatures);695 696    // Add Dest instruction required features.697    std::vector<const Record *> ReqFeatures;698    std::vector<const Record *> RF =699        Dest.TheDef->getValueAsListOfDefs("Predicates");700    copy_if(RF, std::back_inserter(ReqFeatures), [](const Record *R) {701      return R->getValueAsBit("AssemblerMatcherPredicate");702    });703    getReqFeatures(FeaturesSet, AnyOfFeatureSets, ReqFeatures);704 705    ListSeparator CondSep(" &&\n        ");706 707    // Emit checks for all required features.708    for (auto &Op : FeaturesSet) {709      StringRef Not = Op.first ? "!" : "";710      CondStream << CondSep << Not << "STI.getFeatureBits()[" << TargetName711                 << "::" << Op.second << "]";712    }713 714    // Emit checks for all required feature groups.715    for (auto &Set : AnyOfFeatureSets) {716      CondStream << CondSep << "(";717      for (auto &Op : Set) {718        bool IsLast = &Op == &*Set.rbegin();719        StringRef Not = Op.first ? "!" : "";720        CondStream << Not << "STI.getFeatureBits()[" << TargetName721                   << "::" << Op.second << "]";722        if (!IsLast)723          CondStream << " || ";724      }725      CondStream << ")";726    }727 728    // Start Source Inst operands validation.729    unsigned OpNo = 0;730    for (const auto &SourceOperand : Source.Operands) {731      for (unsigned SubOp = 0; SubOp != SourceOperand.MINumOperands; ++SubOp) {732        // Check for fixed immediates\registers in the source instruction.733        switch (SourceOperandMap[OpNo].Kind) {734        case OpData::Operand:735          if (SourceOperandMap[OpNo].OpInfo.TiedOpIdx != -1) {736            if (Source.Operands[OpNo].Rec->isSubClassOf("RegisterClass"))737              CondStream << CondSep << "MI.getOperand(" << OpNo738                         << ").isReg() && MI.getOperand("739                         << SourceOperandMap[OpNo].OpInfo.TiedOpIdx740                         << ").isReg()" << CondSep << "(MI.getOperand(" << OpNo741                         << ").getReg() == MI.getOperand("742                         << SourceOperandMap[OpNo].OpInfo.TiedOpIdx743                         << ").getReg())";744            else745              PrintFatalError("Unexpected tied operand types!");746          }747 748          // We don't need to do anything for source instruction operand checks.749          break;750        case OpData::Imm:751          CondStream << CondSep << "MI.getOperand(" << OpNo << ").isImm()"752                     << CondSep << "(MI.getOperand(" << OpNo753                     << ").getImm() == " << SourceOperandMap[OpNo].ImmVal754                     << ")";755          break;756        case OpData::Reg: {757          const Record *Reg = SourceOperandMap[OpNo].RegRec;758          CondStream << CondSep << "MI.getOperand(" << OpNo << ").isReg()"759                     << CondSep << "(MI.getOperand(" << OpNo760                     << ").getReg() == " << TargetName << "::" << Reg->getName()761                     << ")";762          break;763        }764        }765        ++OpNo;766      }767    }768    CodeStream.indent(6) << "// " << Dest.AsmString << "\n";769    if (CompressOrUncompress)770      CodeStream.indent(6) << "OutInst.setOpcode(" << TargetName771                           << "::" << Dest.getName() << ");\n";772    OpNo = 0;773    for (const auto &DestOperand : Dest.Operands) {774      CodeStream.indent(6) << "// Operand: " << DestOperand.Name << "\n";775 776      for (unsigned SubOp = 0; SubOp != DestOperand.MINumOperands; ++SubOp) {777        const Record *DestRec = DestOperand.Rec;778 779        if (DestOperand.MINumOperands > 1)780          DestRec =781              cast<DefInit>(DestOperand.MIOperandInfo->getArg(SubOp))->getDef();782 783        switch (DestOperandMap[OpNo].Kind) {784        case OpData::Operand: {785          unsigned OpIdx = DestOperandMap[OpNo].OpInfo.Idx;786          const Record *DagRec = DestOperandMap[OpNo].OpInfo.DagRec;787          // Check that the operand in the Source instruction fits788          // the type for the Dest instruction.789          if (DagRec->isSubClassOf("RegisterClass") ||790              DagRec->isSubClassOf("RegisterOperand")) {791            auto *ClassRec = DagRec->isSubClassOf("RegisterClass")792                                 ? DagRec793                                 : DagRec->getValueAsDef("RegClass");794            // This is a register operand. Check the register class.795            // Don't check register class if this is a tied operand, it was done796            // for the operand it's tied to.797            if (DestOperand.getTiedRegister() == -1) {798              CondStream << CondSep << "MI.getOperand(" << OpIdx << ").isReg()";799              if (EType == EmitterType::CheckCompress)800                CondStream << " && MI.getOperand(" << OpIdx801                           << ").getReg().isPhysical()";802              CondStream << CondSep << TargetName << "MCRegisterClasses["803                         << TargetName << "::" << ClassRec->getName()804                         << "RegClassID].contains(MI.getOperand(" << OpIdx805                         << ").getReg())";806            }807 808            if (CompressOrUncompress)809              CodeStream.indent(6)810                  << "OutInst.addOperand(MI.getOperand(" << OpIdx << "));\n";811          } else {812            // Handling immediate operands.813            if (CompressOrUncompress) {814              unsigned Entry = getPredicates(MCOpPredicateMap, MCOpPredicates,815                                             DagRec, "MCOperandPredicate");816              CondStream << CondSep << ValidatorName << "("817                         << "MI.getOperand(" << OpIdx << "), STI, " << Entry818                         << " /* " << DagRec->getName() << " */)";819              // Also check DestRec if different than DagRec.820              if (DagRec != DestRec) {821                Entry = getPredicates(MCOpPredicateMap, MCOpPredicates, DestRec,822                                      "MCOperandPredicate");823                CondStream << CondSep << ValidatorName << "("824                           << "MI.getOperand(" << OpIdx << "), STI, " << Entry825                           << " /* " << DestRec->getName() << " */)";826              }827            } else {828              unsigned Entry =829                  getPredicates(ImmLeafPredicateMap, ImmLeafPredicates, DagRec,830                                "ImmediateCode");831              CondStream << CondSep << "MI.getOperand(" << OpIdx << ").isImm()";832              CondStream << CondSep << TargetName << "ValidateMachineOperand("833                         << "MI.getOperand(" << OpIdx << "), &STI, " << Entry834                         << " /* " << DagRec->getName() << " */)";835              if (DagRec != DestRec) {836                Entry = getPredicates(ImmLeafPredicateMap, ImmLeafPredicates,837                                      DestRec, "ImmediateCode");838                CondStream << CondSep << "MI.getOperand(" << OpIdx839                           << ").isImm()";840                CondStream << CondSep << TargetName << "ValidateMachineOperand("841                           << "MI.getOperand(" << OpIdx << "), &STI, " << Entry842                           << " /* " << DestRec->getName() << " */)";843              }844            }845            if (CompressOrUncompress)846              CodeStream.indent(6)847                  << "OutInst.addOperand(MI.getOperand(" << OpIdx << "));\n";848          }849          break;850        }851        case OpData::Imm: {852          if (CompressOrUncompress) {853            unsigned Entry = getPredicates(MCOpPredicateMap, MCOpPredicates,854                                           DestRec, "MCOperandPredicate");855            CondStream << CondSep << ValidatorName << "("856                       << "MCOperand::createImm(" << DestOperandMap[OpNo].ImmVal857                       << "), STI, " << Entry << " /* " << DestRec->getName()858                       << " */)";859          } else {860            unsigned Entry =861                getPredicates(ImmLeafPredicateMap, ImmLeafPredicates, DestRec,862                              "ImmediateCode");863            CondStream << CondSep << TargetName864                       << "ValidateMachineOperand(MachineOperand::CreateImm("865                       << DestOperandMap[OpNo].ImmVal << "), &STI, " << Entry866                       << " /* " << DestRec->getName() << " */)";867          }868          if (CompressOrUncompress)869            CodeStream.indent(6) << "OutInst.addOperand(MCOperand::createImm("870                                 << DestOperandMap[OpNo].ImmVal << "));\n";871        } break;872        case OpData::Reg: {873          if (CompressOrUncompress) {874            // Fixed register has been validated at pattern validation time.875            const Record *Reg = DestOperandMap[OpNo].RegRec;876            CodeStream.indent(6)877                << "OutInst.addOperand(MCOperand::createReg(" << TargetName878                << "::" << Reg->getName() << "));\n";879          }880        } break;881        }882        ++OpNo;883      }884    }885    if (CompressOrUncompress)886      CodeStream.indent(6) << "OutInst.setLoc(MI.getLoc());\n";887    mergeCondAndCode(CaseStream, CondString, CodeString);888    PrevOp = CurOp;889  }890  Func << CaseString;891  Func.indent(4) << "break;\n";892  // Close brace for the last case.893  Func.indent(2) << "} // case " << CurOp << "\n";894  Func.indent(2) << "} // switch\n";895  Func.indent(2) << "return false;\n}\n";896 897  if (!MCOpPredicates.empty()) {898    auto IndentLength = ValidatorName.size() + 13;899    OS << "static bool " << ValidatorName << "(const MCOperand &MCOp,\n";900    OS.indent(IndentLength) << "const MCSubtargetInfo &STI,\n";901    OS.indent(IndentLength) << "unsigned PredicateIndex) {\n";902    OS << "  switch (PredicateIndex) {\n"903       << "  default:\n"904       << "    llvm_unreachable(\"Unknown MCOperandPredicate kind\");\n"905       << "    break;\n";906 907    printPredicates(MCOpPredicates, "MCOperandPredicate", OS);908 909    OS << "  }\n"910       << "}\n\n";911  }912 913  if (!ImmLeafPredicates.empty()) {914    auto IndentLength = TargetName.size() + 35;915    OS << "static bool " << TargetName916       << "ValidateMachineOperand(const MachineOperand &MO,\n";917    OS.indent(IndentLength)918        << "const " << TargetName << "Subtarget *Subtarget,\n";919    OS.indent(IndentLength)920        << "unsigned PredicateIndex) {\n"921        << "  int64_t Imm = MO.getImm();\n"922        << "  switch (PredicateIndex) {\n"923        << "  default:\n"924        << "    llvm_unreachable(\"Unknown ImmLeaf Predicate kind\");\n"925        << "    break;\n";926 927    printPredicates(ImmLeafPredicates, "ImmediateCode", OS);928 929    OS << "  }\n"930       << "}\n\n";931  }932 933  OS << FH;934  OS << F;935 936  if (EType == EmitterType::Compress)937    OS << "\n#endif //GEN_COMPRESS_INSTR\n";938  else if (EType == EmitterType::Uncompress)939    OS << "\n#endif //GEN_UNCOMPRESS_INSTR\n\n";940  else if (EType == EmitterType::CheckCompress)941    OS << "\n#endif //GEN_CHECK_COMPRESS_INSTR\n\n";942}943 944void CompressInstEmitter::run(raw_ostream &OS) {945  // Process the CompressPat definitions, validating them as we do so.946  for (const Record *Pat : Records.getAllDerivedDefinitions("CompressPat"))947    evaluateCompressPat(Pat);948 949  // Emit file header.950  emitSourceFileHeader("Compress instruction Source Fragment", OS, Records);951  // Generate compressInst() function.952  emitCompressInstEmitter(OS, EmitterType::Compress);953  // Generate uncompressInst() function.954  emitCompressInstEmitter(OS, EmitterType::Uncompress);955  // Generate isCompressibleInst() function.956  emitCompressInstEmitter(OS, EmitterType::CheckCompress);957}958 959static TableGen::Emitter::OptClass<CompressInstEmitter>960    X("gen-compress-inst-emitter", "Generate compressed instructions.");961