utils/TableGen/ExegesisEmitter.cpp

   1 //===- ExegesisEmitter.cpp - Generate exegesis target data ----------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This tablegen backend emits llvm-exegesis information.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ADT/STLExtras.h"
  14 #include "llvm/ADT/SmallSet.h"
  15 #include "llvm/ADT/StringRef.h"
  16 #include "llvm/Support/Debug.h"
  17 #include "llvm/Support/Format.h"
  18 #include "llvm/Support/raw_ostream.h"
  19 #include "llvm/TableGen/Error.h"
  20 #include "llvm/TableGen/Record.h"
  21 #include "llvm/TableGen/TableGenBackend.h"
  22 #include <algorithm>
  23 #include <cassert>
  24 #include <cstdint>
  25 #include <map>
  26 #include <string>
  27 #include <vector>
  28
  29 using namespace llvm;
  30
  31 #define DEBUG_TYPE "exegesis-emitter"
  32
  33 namespace {
  34
  35 class ExegesisEmitter {
  36 public:
  37   ExegesisEmitter(RecordKeeper &RK);
  38
  39   void run(raw_ostream &OS) const;
  40
  41 private:
  42   unsigned getPfmCounterId(llvm::StringRef Name) const {
  43     const auto It = PfmCounterNameTable.find(Name);
  44     if (It == PfmCounterNameTable.end())
  45       PrintFatalError("no pfm counter id for " + Name);
  46     return It->second;
  47   }
  48
  49   // Collects all the ProcPfmCounters definitions available in this target.
  50   void emitPfmCounters(raw_ostream &OS) const;
  51
  52   void emitPfmCountersInfo(const Record &Def,
  53                            unsigned &IssueCountersTableOffset,
  54                            raw_ostream &OS) const;
  55
  56   void emitPfmCountersLookupTable(raw_ostream &OS) const;
  57
  58   RecordKeeper &Records;
  59   std::string Target;
  60
  61   // Table of counter name -> counter index.
  62   const std::map<llvm::StringRef, unsigned> PfmCounterNameTable;
  63 };
  64
  65 static std::map<llvm::StringRef, unsigned>
  66 collectPfmCounters(const RecordKeeper &Records) {
  67   std::map<llvm::StringRef, unsigned> PfmCounterNameTable;
  68   const auto AddPfmCounterName = [&PfmCounterNameTable](
  69                                      const Record *PfmCounterDef) {
  70     const llvm::StringRef Counter = PfmCounterDef->getValueAsString("Counter");
  71     if (!Counter.empty())
  72       PfmCounterNameTable.emplace(Counter, 0);
  73   };
  74   for (Record *Def : Records.getAllDerivedDefinitions("ProcPfmCounters")) {
  75     // Check that ResourceNames are unique.
  76     llvm::SmallSet<llvm::StringRef, 16> Seen;
  77     for (const Record *IssueCounter :
  78          Def->getValueAsListOfDefs("IssueCounters")) {
  79       const llvm::StringRef ResourceName =
  80           IssueCounter->getValueAsString("ResourceName");
  81       if (ResourceName.empty())
  82         PrintFatalError(IssueCounter->getLoc(), "invalid empty ResourceName");
  83       if (!Seen.insert(ResourceName).second)
  84         PrintFatalError(IssueCounter->getLoc(),
  85                         "duplicate ResourceName " + ResourceName);
  86       AddPfmCounterName(IssueCounter);
  87     }
  88     AddPfmCounterName(Def->getValueAsDef("CycleCounter"));
  89     AddPfmCounterName(Def->getValueAsDef("UopsCounter"));
  90   }
  91   unsigned Index = 0;
  92   for (auto &NameAndIndex : PfmCounterNameTable)
  93     NameAndIndex.second = Index++;
  94   return PfmCounterNameTable;
  95 }
  96
  97 ExegesisEmitter::ExegesisEmitter(RecordKeeper &RK)
  98     : Records(RK), PfmCounterNameTable(collectPfmCounters(RK)) {
  99   std::vector<Record *> Targets = Records.getAllDerivedDefinitions("Target");
 100   if (Targets.size() == 0)
 101     PrintFatalError("ERROR: No 'Target' subclasses defined!");
 102   if (Targets.size() != 1)
 103     PrintFatalError("ERROR: Multiple subclasses of Target defined!");
 104   Target = Targets[0]->getName();
 105 }
 106
 107 void ExegesisEmitter::emitPfmCountersInfo(const Record &Def,
 108                                           unsigned &IssueCountersTableOffset,
 109                                           raw_ostream &OS) const {
 110   const auto CycleCounter =
 111       Def.getValueAsDef("CycleCounter")->getValueAsString("Counter");
 112   const auto UopsCounter =
 113       Def.getValueAsDef("UopsCounter")->getValueAsString("Counter");
 114   const size_t NumIssueCounters =
 115       Def.getValueAsListOfDefs("IssueCounters").size();
 116
 117   OS << "\nstatic const PfmCountersInfo " << Target << Def.getName()
 118      << " = {\n";
 119
 120   // Cycle Counter.
 121   if (CycleCounter.empty())
 122     OS << "  nullptr,  // No cycle counter.\n";
 123   else
 124     OS << "  " << Target << "PfmCounterNames[" << getPfmCounterId(CycleCounter)
 125        << "],  // Cycle counter\n";
 126
 127   // Uops Counter.
 128   if (UopsCounter.empty())
 129     OS << "  nullptr,  // No uops counter.\n";
 130   else
 131     OS << "  " << Target << "PfmCounterNames[" << getPfmCounterId(UopsCounter)
 132        << "],  // Uops counter\n";
 133
 134   // Issue Counters
 135   if (NumIssueCounters == 0)
 136     OS << "  nullptr,  // No issue counters.\n  0\n";
 137   else
 138     OS << "  " << Target << "PfmIssueCounters + " << IssueCountersTableOffset
 139        << ", " << NumIssueCounters << " // Issue counters.\n";
 140
 141   OS << "};\n";
 142   IssueCountersTableOffset += NumIssueCounters;
 143 }
 144
 145 void ExegesisEmitter::emitPfmCounters(raw_ostream &OS) const {
 146   // Emit the counter name table.
 147   OS << "\nstatic const char* " << Target << "PfmCounterNames[] = {\n";
 148   for (const auto &NameAndIndex : PfmCounterNameTable)
 149     OS << "  \"" << NameAndIndex.first << "\", // " << NameAndIndex.second
 150        << "\n";
 151   OS << "};\n\n";
 152
 153   // Emit the IssueCounters table.
 154   const auto PfmCounterDefs =
 155       Records.getAllDerivedDefinitions("ProcPfmCounters");
 156   // Only emit if non-empty.
 157   const bool HasAtLeastOnePfmIssueCounter =
 158       llvm::any_of(PfmCounterDefs, [](const Record *Def) {
 159         return !Def->getValueAsListOfDefs("IssueCounters").empty();
 160       });
 161   if (HasAtLeastOnePfmIssueCounter) {
 162     OS << "static const PfmCountersInfo::IssueCounter " << Target
 163        << "PfmIssueCounters[] = {\n";
 164     for (const Record *Def : PfmCounterDefs) {
 165       for (const Record *ICDef : Def->getValueAsListOfDefs("IssueCounters"))
 166         OS << "  { " << Target << "PfmCounterNames["
 167            << getPfmCounterId(ICDef->getValueAsString("Counter")) << "], \""
 168            << ICDef->getValueAsString("ResourceName") << "\"},\n";
 169     }
 170     OS << "};\n";
 171   }
 172
 173   // Now generate the PfmCountersInfo.
 174   unsigned IssueCountersTableOffset = 0;
 175   for (const Record *Def : PfmCounterDefs)
 176     emitPfmCountersInfo(*Def, IssueCountersTableOffset, OS);
 177
 178   OS << "\n";
 179 } // namespace
 180
 181 void ExegesisEmitter::emitPfmCountersLookupTable(raw_ostream &OS) const {
 182   std::vector<Record *> Bindings =
 183       Records.getAllDerivedDefinitions("PfmCountersBinding");
 184   assert(!Bindings.empty() && "there must be at least one binding");
 185   llvm::sort(Bindings, [](const Record *L, const Record *R) {
 186     return L->getValueAsString("CpuName") < R->getValueAsString("CpuName");
 187   });
 188
 189   OS << "// Sorted (by CpuName) array of pfm counters.\n"
 190      << "static const CpuAndPfmCounters " << Target << "CpuPfmCounters[] = {\n";
 191   for (Record *Binding : Bindings) {
 192     // Emit as { "cpu", procinit },
 193     OS << "  { \""                                                        //
 194        << Binding->getValueAsString("CpuName") << "\","                   //
 195        << " &" << Target << Binding->getValueAsDef("Counters")->getName() //
 196        << " },\n";
 197   }
 198   OS << "};\n\n";
 199 }
 200
 201 void ExegesisEmitter::run(raw_ostream &OS) const {
 202   emitSourceFileHeader("Exegesis Tables", OS);
 203   emitPfmCounters(OS);
 204   emitPfmCountersLookupTable(OS);
 205 }
 206
 207 } // end anonymous namespace
 208
 209 namespace llvm {
 210
 211 void EmitExegesis(RecordKeeper &RK, raw_ostream &OS) {
 212   ExegesisEmitter(RK).run(OS);
 213 }
 214
 215 } // end namespace llvm