1 //===- ExegesisEmitter.cpp - Generate exegesis target data ----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This tablegen backend emits llvm-exegesis information.
11 //
12 //===----------------------------------------------------------------------===//
13 
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   // This is the default, do not emit.
118   if (CycleCounter.empty() && UopsCounter.empty() && NumIssueCounters == 0)
119     return;
120 
121   OS << "\nstatic const PfmCountersInfo " << Target << Def.getName()
122      << " = {\n";
123 
124   // Cycle Counter.
125   if (CycleCounter.empty())
126     OS << "  nullptr,  // No cycle counter.\n";
127   else
128     OS << "  " << Target << "PfmCounterNames[" << getPfmCounterId(CycleCounter)
129        << "],  // Cycle counter\n";
130 
131   // Uops Counter.
132   if (UopsCounter.empty())
133     OS << "  nullptr,  // No uops counter.\n";
134   else
135     OS << "  " << Target << "PfmCounterNames[" << getPfmCounterId(UopsCounter)
136        << "],  // Uops counter\n";
137 
138   // Issue Counters
139   if (NumIssueCounters == 0)
140     OS << "  nullptr,  // No issue counters.\n  0\n";
141   else
142     OS << "  " << Target << "PfmIssueCounters + " << IssueCountersTableOffset
143        << ", " << NumIssueCounters << " // Issue counters.\n";
144 
145   OS << "};\n";
146   IssueCountersTableOffset += NumIssueCounters;
147 }
148 
149 void ExegesisEmitter::emitPfmCounters(raw_ostream &OS) const {
150   // Emit the counter name table.
151   OS << "\nstatic const char* " << Target << "PfmCounterNames[] = {\n";
152   for (const auto &NameAndIndex : PfmCounterNameTable)
153     OS << "  \"" << NameAndIndex.first << "\", // " << NameAndIndex.second
154        << "\n";
155   OS << "};\n\n";
156 
157   // Emit the IssueCounters table.
158   const auto PfmCounterDefs =
159       Records.getAllDerivedDefinitions("ProcPfmCounters");
160   OS << "static const PfmCountersInfo::IssueCounter " << Target
161      << "PfmIssueCounters[] = {\n";
162   for (const Record *Def : PfmCounterDefs) {
163     for (const Record *ICDef : Def->getValueAsListOfDefs("IssueCounters"))
164       OS << "  { " << Target << "PfmCounterNames["
165          << getPfmCounterId(ICDef->getValueAsString("Counter")) << "], \""
166          << ICDef->getValueAsString("ResourceName") << "\"},\n";
167   }
168 
169   OS << "};\n";
170 
171   // Now generate the PfmCountersInfo.
172   unsigned IssueCountersTableOffset = 0;
173   for (const Record *Def : PfmCounterDefs)
174     emitPfmCountersInfo(*Def, IssueCountersTableOffset, OS);
175 
176   OS << "\n";
177 }
178 
179 void ExegesisEmitter::emitPfmCountersLookupTable(raw_ostream &OS) const {
180   std::vector<Record *> Bindings =
181       Records.getAllDerivedDefinitions("PfmCountersBinding");
182   llvm::sort(Bindings, [](const Record *L, const Record *R) {
183     return L->getValueAsString("CpuName") < R->getValueAsString("CpuName");
184   });
185 
186   OS << "// Sorted (by CpuName) array of pfm counters.\n"
187      << "static const CpuAndPfmCounters " << Target << "CpuPfmCounters[] = {\n";
188   for (Record *Binding : Bindings) {
189     // Emit as { "cpu", procinit },
190     OS << "  { \""                                                        //
191        << Binding->getValueAsString("CpuName") << "\","                   //
192        << " &" << Target << Binding->getValueAsDef("Counters")->getName() //
193        << " },\n";
194   }
195   OS << "};\n\n";
196 }
197 
198 void ExegesisEmitter::run(raw_ostream &OS) const {
199   emitSourceFileHeader("Exegesis Tables", OS);
200   emitPfmCounters(OS);
201   emitPfmCountersLookupTable(OS);
202 }
203 
204 } // end anonymous namespace
205 
206 namespace llvm {
207 
208 void EmitExegesis(RecordKeeper &RK, raw_ostream &OS) {
209   ExegesisEmitter(RK).run(OS);
210 }
211 
212 } // end namespace llvm
213