path: root/utils/TableGen/SubtargetEmitter.cpp

//===- SubtargetEmitter.cpp - Generate subtarget enumerations -------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This tablegen backend emits subtarget enumerations.
//
//===----------------------------------------------------------------------===//

#include "CodeGenTarget.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/Support/Debug.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
#include <algorithm>
#include <map>
#include <string>
#include <vector>
using namespace llvm;

namespace {
class SubtargetEmitter {

  RecordKeeper &Records;
  std::string Target;
  bool HasItineraries;

  void Enumeration(raw_ostream &OS, const char *ClassName, bool isBits);
  unsigned FeatureKeyValues(raw_ostream &OS);
  unsigned CPUKeyValues(raw_ostream &OS);
  unsigned CollectAllItinClasses(raw_ostream &OS,
                                 std::map<std::string,unsigned> &ItinClassesMap,
                                 std::vector<Record*> &ItinClassList);
  void FormItineraryStageString(const std::string &Names,
                                Record *ItinData, std::string &ItinString,
                                unsigned &NStages);
  void FormItineraryOperandCycleString(Record *ItinData, std::string &ItinString,
                                       unsigned &NOperandCycles);
  void FormItineraryBypassString(const std::string &Names,
                                 Record *ItinData,
                                 std::string &ItinString, unsigned NOperandCycles);
  void EmitStageAndOperandCycleData(raw_ostream &OS, unsigned NItinClasses,
                     std::map<std::string, unsigned> &ItinClassesMap,
                     std::vector<Record*> &ItinClassList,
                     std::vector<std::vector<InstrItinerary> > &ProcList);
  void EmitItineraryProp(raw_ostream &OS, const Record *R, const char *Name,
                         char Separator);
  void EmitProcessorData(raw_ostream &OS,
                         std::vector<Record*> &ItinClassList,
                         std::vector<std::vector<InstrItinerary> > &ProcList);
  void EmitProcessorLookup(raw_ostream &OS);
  void EmitData(raw_ostream &OS);
  void ParseFeaturesFunction(raw_ostream &OS, unsigned NumFeatures,
                             unsigned NumProcs);

public:
  SubtargetEmitter(RecordKeeper &R) : Records(R), HasItineraries(false) {}

  void run(raw_ostream &o);

};
} // End anonymous namespace

//
// Enumeration - Emit the specified class as an enumeration.
//
void SubtargetEmitter::Enumeration(raw_ostream &OS,
                                   const char *ClassName,
                                   bool isBits) {
  // Get all records of class and sort
  std::vector<Record*> DefList = Records.getAllDerivedDefinitions(ClassName);
  std::sort(DefList.begin(), DefList.end(), LessRecord());

  unsigned N = DefList.size();
  if (N == 0)
    return;
  if (N > 64) {
    errs() << "Too many (> 64) subtarget features!\n";
    exit(1);
  }

  OS << "namespace " << Target << " {\n";

  // For bit flag enumerations with more than 32 items, emit constants.
  // Emit an enum for everything else.
  if (isBits && N > 32) {
    // For each record
    for (unsigned i = 0; i < N; i++) {
      // Next record
      Record *Def = DefList[i];

      // Get and emit name and expression (1 << i)
      OS << "  const uint64_t " << Def->getName() << " = 1ULL << " << i << ";\n";
    }
  } else {
    // Open enumeration
    OS << "enum {\n";

    // For each record
    for (unsigned i = 0; i < N;) {
      // Next record
      Record *Def = DefList[i];

      // Get and emit name
      OS << "  " << Def->getName();

      // If bit flags then emit expression (1 << i)
      if (isBits)  OS << " = " << " 1ULL << " << i;

      // Depending on 'if more in the list' emit comma
      if (++i < N) OS << ",";

      OS << "\n";
    }

    // Close enumeration
    OS << "};\n";
  }

  OS << "}\n";
}

//
// FeatureKeyValues - Emit data of all the subtarget features.  Used by the
// command line.
//
unsigned SubtargetEmitter::FeatureKeyValues(raw_ostream &OS) {
  // Gather and sort all the features
  std::vector<Record*> FeatureList =
                           Records.getAllDerivedDefinitions("SubtargetFeature");

  if (FeatureList.empty())
    return 0;

  std::sort(FeatureList.begin(), FeatureList.end(), LessRecordFieldName());

  // Begin feature table
  OS << "// Sorted (by key) array of values for CPU features.