1 //===- InstrProfWriter.cpp - Instrumented profiling writer ----------------===// 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 file contains support for writing profiling data for clang's 11 // instrumentation based PGO and coverage. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/ProfileData/InstrProfWriter.h" 16 #include "llvm/ADT/STLExtras.h" 17 #include "llvm/ADT/StringRef.h" 18 #include "llvm/IR/ProfileSummary.h" 19 #include "llvm/ProfileData/InstrProf.h" 20 #include "llvm/ProfileData/ProfileCommon.h" 21 #include "llvm/Support/Endian.h" 22 #include "llvm/Support/EndianStream.h" 23 #include "llvm/Support/Error.h" 24 #include "llvm/Support/MemoryBuffer.h" 25 #include "llvm/Support/OnDiskHashTable.h" 26 #include "llvm/Support/raw_ostream.h" 27 #include <algorithm> 28 #include <cstdint> 29 #include <memory> 30 #include <string> 31 #include <tuple> 32 #include <utility> 33 #include <vector> 34 35 using namespace llvm; 36 37 // A struct to define how the data stream should be patched. For Indexed 38 // profiling, only uint64_t data type is needed. 39 struct PatchItem { 40 uint64_t Pos; // Where to patch. 41 uint64_t *D; // Pointer to an array of source data. 42 int N; // Number of elements in \c D array. 43 }; 44 45 namespace llvm { 46 47 // A wrapper class to abstract writer stream with support of bytes 48 // back patching. 49 class ProfOStream { 50 public: 51 ProfOStream(raw_fd_ostream &FD) 52 : IsFDOStream(true), OS(FD), LE(FD, support::little) {} 53 ProfOStream(raw_string_ostream &STR) 54 : IsFDOStream(false), OS(STR), LE(STR, support::little) {} 55 56 uint64_t tell() { return OS.tell(); } 57 void write(uint64_t V) { LE.write<uint64_t>(V); } 58 59 // \c patch can only be called when all data is written and flushed. 60 // For raw_string_ostream, the patch is done on the target string 61 // directly and it won't be reflected in the stream's internal buffer. 62 void patch(PatchItem *P, int NItems) { 63 using namespace support; 64 65 if (IsFDOStream) { 66 raw_fd_ostream &FDOStream = static_cast<raw_fd_ostream &>(OS); 67 for (int K = 0; K < NItems; K++) { 68 FDOStream.seek(P[K].Pos); 69 for (int I = 0; I < P[K].N; I++) 70 write(P[K].D[I]); 71 } 72 } else { 73 raw_string_ostream &SOStream = static_cast<raw_string_ostream &>(OS); 74 std::string &Data = SOStream.str(); // with flush 75 for (int K = 0; K < NItems; K++) { 76 for (int I = 0; I < P[K].N; I++) { 77 uint64_t Bytes = endian::byte_swap<uint64_t, little>(P[K].D[I]); 78 Data.replace(P[K].Pos + I * sizeof(uint64_t), sizeof(uint64_t), 79 (const char *)&Bytes, sizeof(uint64_t)); 80 } 81 } 82 } 83 } 84 85 // If \c OS is an instance of \c raw_fd_ostream, this field will be 86 // true. Otherwise, \c OS will be an raw_string_ostream. 87 bool IsFDOStream; 88 raw_ostream &OS; 89 support::endian::Writer LE; 90 }; 91 92 class InstrProfRecordWriterTrait { 93 public: 94 using key_type = StringRef; 95 using key_type_ref = StringRef; 96 97 using data_type = const InstrProfWriter::ProfilingData *const; 98 using data_type_ref = const InstrProfWriter::ProfilingData *const; 99 100 using hash_value_type = uint64_t; 101 using offset_type = uint64_t; 102 103 support::endianness ValueProfDataEndianness = support::little; 104 InstrProfSummaryBuilder *SummaryBuilder; 105 106 InstrProfRecordWriterTrait() = default; 107 108 static hash_value_type ComputeHash(key_type_ref K) { 109 return IndexedInstrProf::ComputeHash(K); 110 } 111 112 static std::pair<offset_type, offset_type> 113 EmitKeyDataLength(raw_ostream &Out, key_type_ref K, data_type_ref V) { 114 using namespace support; 115 116 endian::Writer LE(Out, little); 117 118 offset_type N = K.size(); 119 LE.write<offset_type>(N); 120 121 offset_type M = 0; 122 for (const auto &ProfileData : *V) { 123 const InstrProfRecord &ProfRecord = ProfileData.second; 124 M += sizeof(uint64_t); // The function hash 125 M += sizeof(uint64_t); // The size of the Counts vector 126 M += ProfRecord.Counts.size() * sizeof(uint64_t); 127 128 // Value data 129 M += ValueProfData::getSize(ProfileData.second); 130 } 131 LE.write<offset_type>(M); 132 133 return std::make_pair(N, M); 134 } 135 136 void EmitKey(raw_ostream &Out, key_type_ref K, offset_type N) { 137 Out.write(K.data(), N); 138 } 139 140 void EmitData(raw_ostream &Out, key_type_ref, data_type_ref V, offset_type) { 141 using namespace support; 142 143 endian::Writer LE(Out, little); 144 for (const auto &ProfileData : *V) { 145 const InstrProfRecord &ProfRecord = ProfileData.second; 146 SummaryBuilder->addRecord(ProfRecord); 147 148 LE.write<uint64_t>(ProfileData.first); // Function hash 149 LE.write<uint64_t>(ProfRecord.Counts.size()); 150 for (uint64_t I : ProfRecord.Counts) 151 LE.write<uint64_t>(I); 152 153 // Write value data 154 std::unique_ptr<ValueProfData> VDataPtr = 155 ValueProfData::serializeFrom(ProfileData.second); 156 uint32_t S = VDataPtr->getSize(); 157 VDataPtr->swapBytesFromHost(ValueProfDataEndianness); 158 Out.write((const char *)VDataPtr.get(), S); 159 } 160 } 161 }; 162 163 } // end namespace llvm 164 165 InstrProfWriter::InstrProfWriter(bool Sparse) 166 : Sparse(Sparse), InfoObj(new InstrProfRecordWriterTrait()) {} 167 168 InstrProfWriter::~InstrProfWriter() { delete InfoObj; } 169 170 // Internal interface for testing purpose only. 171 void InstrProfWriter::setValueProfDataEndianness( 172 support::endianness Endianness) { 173 InfoObj->ValueProfDataEndianness = Endianness; 174 } 175 176 void InstrProfWriter::setOutputSparse(bool Sparse) { 177 this->Sparse = Sparse; 178 } 179 180 void InstrProfWriter::addRecord(NamedInstrProfRecord &&I, uint64_t Weight, 181 function_ref<void(Error)> Warn) { 182 auto Name = I.Name; 183 auto Hash = I.Hash; 184 addRecord(Name, Hash, std::move(I), Weight, Warn); 185 } 186 187 void InstrProfWriter::addRecord(StringRef Name, uint64_t Hash, 188 InstrProfRecord &&I, uint64_t Weight, 189 function_ref<void(Error)> Warn) { 190 auto &ProfileDataMap = FunctionData[Name]; 191 192 bool NewFunc; 193 ProfilingData::iterator Where; 194 std::tie(Where, NewFunc) = 195 ProfileDataMap.insert(std::make_pair(Hash, InstrProfRecord())); 196 InstrProfRecord &Dest = Where->second; 197 198 auto MapWarn = [&](instrprof_error E) { 199 Warn(make_error<InstrProfError>(E)); 200 }; 201 202 if (NewFunc) { 203 // We've never seen a function with this name and hash, add it. 204 Dest = std::move(I); 205 if (Weight > 1) 206 Dest.scale(Weight, MapWarn); 207 } else { 208 // We're updating a function we've seen before. 209 Dest.merge(I, Weight, MapWarn); 210 } 211 212 Dest.sortValueData(); 213 } 214 215 void InstrProfWriter::mergeRecordsFromWriter(InstrProfWriter &&IPW, 216 function_ref<void(Error)> Warn) { 217 for (auto &I : IPW.FunctionData) 218 for (auto &Func : I.getValue()) 219 addRecord(I.getKey(), Func.first, std::move(Func.second), 1, Warn); 220 } 221 222 bool InstrProfWriter::shouldEncodeData(const ProfilingData &PD) { 223 if (!Sparse) 224 return true; 225 for (const auto &Func : PD) { 226 const InstrProfRecord &IPR = Func.second; 227 if (llvm::any_of(IPR.Counts, [](uint64_t Count) { return Count > 0; })) 228 return true; 229 } 230 return false; 231 } 232 233 static void setSummary(IndexedInstrProf::Summary *TheSummary, 234 ProfileSummary &PS) { 235 using namespace IndexedInstrProf; 236 237 std::vector<ProfileSummaryEntry> &Res = PS.getDetailedSummary(); 238 TheSummary->NumSummaryFields = Summary::NumKinds; 239 TheSummary->NumCutoffEntries = Res.size(); 240 TheSummary->set(Summary::MaxFunctionCount, PS.getMaxFunctionCount()); 241 TheSummary->set(Summary::MaxBlockCount, PS.getMaxCount()); 242 TheSummary->set(Summary::MaxInternalBlockCount, PS.getMaxInternalCount()); 243 TheSummary->set(Summary::TotalBlockCount, PS.getTotalCount()); 244 TheSummary->set(Summary::TotalNumBlocks, PS.getNumCounts()); 245 TheSummary->set(Summary::TotalNumFunctions, PS.getNumFunctions()); 246 for (unsigned I = 0; I < Res.size(); I++) 247 TheSummary->setEntry(I, Res[I]); 248 } 249 250 void InstrProfWriter::writeImpl(ProfOStream &OS) { 251 using namespace IndexedInstrProf; 252 253 OnDiskChainedHashTableGenerator<InstrProfRecordWriterTrait> Generator; 254 255 InstrProfSummaryBuilder ISB(ProfileSummaryBuilder::DefaultCutoffs); 256 InfoObj->SummaryBuilder = &ISB; 257 258 // Populate the hash table generator. 259 for (const auto &I : FunctionData) 260 if (shouldEncodeData(I.getValue())) 261 Generator.insert(I.getKey(), &I.getValue()); 262 // Write the header. 263 IndexedInstrProf::Header Header; 264 Header.Magic = IndexedInstrProf::Magic; 265 Header.Version = IndexedInstrProf::ProfVersion::CurrentVersion; 266 if (ProfileKind == PF_IRLevel) 267 Header.Version |= VARIANT_MASK_IR_PROF; 268 Header.Unused = 0; 269 Header.HashType = static_cast<uint64_t>(IndexedInstrProf::HashType); 270 Header.HashOffset = 0; 271 int N = sizeof(IndexedInstrProf::Header) / sizeof(uint64_t); 272 273 // Only write out all the fields except 'HashOffset'. We need 274 // to remember the offset of that field to allow back patching 275 // later. 276 for (int I = 0; I < N - 1; I++) 277 OS.write(reinterpret_cast<uint64_t *>(&Header)[I]); 278 279 // Save the location of Header.HashOffset field in \c OS. 280 uint64_t HashTableStartFieldOffset = OS.tell(); 281 // Reserve the space for HashOffset field. 282 OS.write(0); 283 284 // Reserve space to write profile summary data. 285 uint32_t NumEntries = ProfileSummaryBuilder::DefaultCutoffs.size(); 286 uint32_t SummarySize = Summary::getSize(Summary::NumKinds, NumEntries); 287 // Remember the summary offset. 288 uint64_t SummaryOffset = OS.tell(); 289 for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++) 290 OS.write(0); 291 292 // Write the hash table. 293 uint64_t HashTableStart = Generator.Emit(OS.OS, *InfoObj); 294 295 // Allocate space for data to be serialized out. 296 std::unique_ptr<IndexedInstrProf::Summary> TheSummary = 297 IndexedInstrProf::allocSummary(SummarySize); 298 // Compute the Summary and copy the data to the data 299 // structure to be serialized out (to disk or buffer). 300 std::unique_ptr<ProfileSummary> PS = ISB.getSummary(); 301 setSummary(TheSummary.get(), *PS); 302 InfoObj->SummaryBuilder = nullptr; 303 304 // Now do the final patch: 305 PatchItem PatchItems[] = { 306 // Patch the Header.HashOffset field. 307 {HashTableStartFieldOffset, &HashTableStart, 1}, 308 // Patch the summary data. 309 {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()), 310 (int)(SummarySize / sizeof(uint64_t))}}; 311 OS.patch(PatchItems, sizeof(PatchItems) / sizeof(*PatchItems)); 312 } 313 314 void InstrProfWriter::write(raw_fd_ostream &OS) { 315 // Write the hash table. 316 ProfOStream POS(OS); 317 writeImpl(POS); 318 } 319 320 std::unique_ptr<MemoryBuffer> InstrProfWriter::writeBuffer() { 321 std::string Data; 322 raw_string_ostream OS(Data); 323 ProfOStream POS(OS); 324 // Write the hash table. 325 writeImpl(POS); 326 // Return this in an aligned memory buffer. 327 return MemoryBuffer::getMemBufferCopy(Data); 328 } 329 330 static const char *ValueProfKindStr[] = { 331 #define VALUE_PROF_KIND(Enumerator, Value) #Enumerator, 332 #include "llvm/ProfileData/InstrProfData.inc" 333 }; 334 335 void InstrProfWriter::writeRecordInText(StringRef Name, uint64_t Hash, 336 const InstrProfRecord &Func, 337 InstrProfSymtab &Symtab, 338 raw_fd_ostream &OS) { 339 OS << Name << "\n"; 340 OS << "# Func Hash:\n" << Hash << "\n"; 341 OS << "# Num Counters:\n" << Func.Counts.size() << "\n"; 342 OS << "# Counter Values:\n"; 343 for (uint64_t Count : Func.Counts) 344 OS << Count << "\n"; 345 346 uint32_t NumValueKinds = Func.getNumValueKinds(); 347 if (!NumValueKinds) { 348 OS << "\n"; 349 return; 350 } 351 352 OS << "# Num Value Kinds:\n" << Func.getNumValueKinds() << "\n"; 353 for (uint32_t VK = 0; VK < IPVK_Last + 1; VK++) { 354 uint32_t NS = Func.getNumValueSites(VK); 355 if (!NS) 356 continue; 357 OS << "# ValueKind = " << ValueProfKindStr[VK] << ":\n" << VK << "\n"; 358 OS << "# NumValueSites:\n" << NS << "\n"; 359 for (uint32_t S = 0; S < NS; S++) { 360 uint32_t ND = Func.getNumValueDataForSite(VK, S); 361 OS << ND << "\n"; 362 std::unique_ptr<InstrProfValueData[]> VD = Func.getValueForSite(VK, S); 363 for (uint32_t I = 0; I < ND; I++) { 364 if (VK == IPVK_IndirectCallTarget) 365 OS << Symtab.getFuncNameOrExternalSymbol(VD[I].Value) << ":" 366 << VD[I].Count << "\n"; 367 else 368 OS << VD[I].Value << ":" << VD[I].Count << "\n"; 369 } 370 } 371 } 372 373 OS << "\n"; 374 } 375 376 Error InstrProfWriter::writeText(raw_fd_ostream &OS) { 377 if (ProfileKind == PF_IRLevel) 378 OS << "# IR level Instrumentation Flag\n:ir\n"; 379 InstrProfSymtab Symtab; 380 for (const auto &I : FunctionData) 381 if (shouldEncodeData(I.getValue())) 382 if (Error E = Symtab.addFuncName(I.getKey())) 383 return E; 384 385 for (const auto &I : FunctionData) 386 if (shouldEncodeData(I.getValue())) 387 for (const auto &Func : I.getValue()) 388 writeRecordInText(I.getKey(), Func.first, Func.second, Symtab, OS); 389 return Error::success(); 390 } 391
