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