1 //===- InstrProfWriter.cpp - Instrumented profiling writer ----------------===// 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 file contains support for writing profiling data for clang's 10 // instrumentation based PGO and coverage. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/ProfileData/InstrProfWriter.h" 15 #include "llvm/ADT/STLExtras.h" 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/IR/ProfileSummary.h" 18 #include "llvm/ProfileData/InstrProf.h" 19 #include "llvm/ProfileData/ProfileCommon.h" 20 #include "llvm/Support/Endian.h" 21 #include "llvm/Support/EndianStream.h" 22 #include "llvm/Support/Error.h" 23 #include "llvm/Support/MemoryBuffer.h" 24 #include "llvm/Support/OnDiskHashTable.h" 25 #include "llvm/Support/raw_ostream.h" 26 #include <algorithm> 27 #include <cstdint> 28 #include <memory> 29 #include <string> 30 #include <tuple> 31 #include <utility> 32 #include <vector> 33 34 using namespace llvm; 35 36 // A struct to define how the data stream should be patched. For Indexed 37 // profiling, only uint64_t data type is needed. 38 struct PatchItem { 39 uint64_t Pos; // Where to patch. 40 uint64_t *D; // Pointer to an array of source data. 41 int N; // Number of elements in \c D array. 42 }; 43 44 namespace llvm { 45 46 // A wrapper class to abstract writer stream with support of bytes 47 // back patching. 48 class ProfOStream { 49 public: 50 ProfOStream(raw_fd_ostream &FD) 51 : IsFDOStream(true), OS(FD), LE(FD, support::little) {} 52 ProfOStream(raw_string_ostream &STR) 53 : IsFDOStream(false), OS(STR), LE(STR, support::little) {} 54 55 uint64_t tell() { return OS.tell(); } 56 void write(uint64_t V) { LE.write<uint64_t>(V); } 57 58 // \c patch can only be called when all data is written and flushed. 59 // For raw_string_ostream, the patch is done on the target string 60 // directly and it won't be reflected in the stream's internal buffer. 61 void patch(PatchItem *P, int NItems) { 62 using namespace support; 63 64 if (IsFDOStream) { 65 raw_fd_ostream &FDOStream = static_cast<raw_fd_ostream &>(OS); 66 for (int K = 0; K < NItems; K++) { 67 FDOStream.seek(P[K].Pos); 68 for (int I = 0; I < P[K].N; I++) 69 write(P[K].D[I]); 70 } 71 } else { 72 raw_string_ostream &SOStream = static_cast<raw_string_ostream &>(OS); 73 std::string &Data = SOStream.str(); // with flush 74 for (int K = 0; K < NItems; K++) { 75 for (int I = 0; I < P[K].N; I++) { 76 uint64_t Bytes = endian::byte_swap<uint64_t, little>(P[K].D[I]); 77 Data.replace(P[K].Pos + I * sizeof(uint64_t), sizeof(uint64_t), 78 (const char *)&Bytes, sizeof(uint64_t)); 79 } 80 } 81 } 82 } 83 84 // If \c OS is an instance of \c raw_fd_ostream, this field will be 85 // true. Otherwise, \c OS will be an raw_string_ostream. 86 bool IsFDOStream; 87 raw_ostream &OS; 88 support::endian::Writer LE; 89 }; 90 91 class InstrProfRecordWriterTrait { 92 public: 93 using key_type = StringRef; 94 using key_type_ref = StringRef; 95 96 using data_type = const InstrProfWriter::ProfilingData *const; 97 using data_type_ref = const InstrProfWriter::ProfilingData *const; 98 99 using hash_value_type = uint64_t; 100 using offset_type = uint64_t; 101 102 support::endianness ValueProfDataEndianness = support::little; 103 InstrProfSummaryBuilder *SummaryBuilder; 104 InstrProfSummaryBuilder *CSSummaryBuilder; 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 if (NamedInstrProfRecord::hasCSFlagInHash(ProfileData.first)) 147 CSSummaryBuilder->addRecord(ProfRecord); 148 else 149 SummaryBuilder->addRecord(ProfRecord); 150 151 LE.write<uint64_t>(ProfileData.first); // Function hash 152 LE.write<uint64_t>(ProfRecord.Counts.size()); 153 for (uint64_t I : ProfRecord.Counts) 154 LE.write<uint64_t>(I); 155 156 // Write value data 157 std::unique_ptr<ValueProfData> VDataPtr = 158 ValueProfData::serializeFrom(ProfileData.second); 159 uint32_t S = VDataPtr->getSize(); 160 VDataPtr->swapBytesFromHost(ValueProfDataEndianness); 161 Out.write((const char *)VDataPtr.get(), S); 162 } 163 } 164 }; 165 166 } // end namespace llvm 167 168 InstrProfWriter::InstrProfWriter(bool Sparse) 169 : Sparse(Sparse), InfoObj(new InstrProfRecordWriterTrait()) {} 170 171 InstrProfWriter::~InstrProfWriter() { delete InfoObj; } 172 173 // Internal interface for testing purpose only. 174 void InstrProfWriter::setValueProfDataEndianness( 175 support::endianness Endianness) { 176 InfoObj->ValueProfDataEndianness = Endianness; 177 } 178 179 void InstrProfWriter::setOutputSparse(bool Sparse) { 180 this->Sparse = Sparse; 181 } 182 183 void InstrProfWriter::addRecord(NamedInstrProfRecord &&I, uint64_t Weight, 184 function_ref<void(Error)> Warn) { 185 auto Name = I.Name; 186 auto Hash = I.Hash; 187 addRecord(Name, Hash, std::move(I), Weight, Warn); 188 } 189 190 void InstrProfWriter::overlapRecord(NamedInstrProfRecord &&Other, 191 OverlapStats &Overlap, 192 OverlapStats &FuncLevelOverlap, 193 const OverlapFuncFilters &FuncFilter) { 194 auto Name = Other.Name; 195 auto Hash = Other.Hash; 196 Other.accumulateCounts(FuncLevelOverlap.Test); 197 if (FunctionData.find(Name) == FunctionData.end()) { 198 Overlap.addOneUnique(FuncLevelOverlap.Test); 199 return; 200 } 201 if (FuncLevelOverlap.Test.CountSum < 1.0f) { 202 Overlap.Overlap.NumEntries += 1; 203 return; 204 } 205 auto &ProfileDataMap = FunctionData[Name]; 206 bool NewFunc; 207 ProfilingData::iterator Where; 208 std::tie(Where, NewFunc) = 209 ProfileDataMap.insert(std::make_pair(Hash, InstrProfRecord())); 210 if (NewFunc) { 211 Overlap.addOneMismatch(FuncLevelOverlap.Test); 212 return; 213 } 214 InstrProfRecord &Dest = Where->second; 215 216 uint64_t ValueCutoff = FuncFilter.ValueCutoff; 217 if (!FuncFilter.NameFilter.empty() && 218 Name.find(FuncFilter.NameFilter) != Name.npos) 219 ValueCutoff = 0; 220 221 Dest.overlap(Other, Overlap, FuncLevelOverlap, ValueCutoff); 222 } 223 224 void InstrProfWriter::addRecord(StringRef Name, uint64_t Hash, 225 InstrProfRecord &&I, uint64_t Weight, 226 function_ref<void(Error)> Warn) { 227 auto &ProfileDataMap = FunctionData[Name]; 228 229 bool NewFunc; 230 ProfilingData::iterator Where; 231 std::tie(Where, NewFunc) = 232 ProfileDataMap.insert(std::make_pair(Hash, InstrProfRecord())); 233 InstrProfRecord &Dest = Where->second; 234 235 auto MapWarn = [&](instrprof_error E) { 236 Warn(make_error<InstrProfError>(E)); 237 }; 238 239 if (NewFunc) { 240 // We've never seen a function with this name and hash, add it. 241 Dest = std::move(I); 242 if (Weight > 1) 243 Dest.scale(Weight, MapWarn); 244 } else { 245 // We're updating a function we've seen before. 246 Dest.merge(I, Weight, MapWarn); 247 } 248 249 Dest.sortValueData(); 250 } 251 252 void InstrProfWriter::mergeRecordsFromWriter(InstrProfWriter &&IPW, 253 function_ref<void(Error)> Warn) { 254 for (auto &I : IPW.FunctionData) 255 for (auto &Func : I.getValue()) 256 addRecord(I.getKey(), Func.first, std::move(Func.second), 1, Warn); 257 } 258 259 bool InstrProfWriter::shouldEncodeData(const ProfilingData &PD) { 260 if (!Sparse) 261 return true; 262 for (const auto &Func : PD) { 263 const InstrProfRecord &IPR = Func.second; 264 if (llvm::any_of(IPR.Counts, [](uint64_t Count) { return Count > 0; })) 265 return true; 266 } 267 return false; 268 } 269 270 static void setSummary(IndexedInstrProf::Summary *TheSummary, 271 ProfileSummary &PS) { 272 using namespace IndexedInstrProf; 273 274 std::vector<ProfileSummaryEntry> &Res = PS.getDetailedSummary(); 275 TheSummary->NumSummaryFields = Summary::NumKinds; 276 TheSummary->NumCutoffEntries = Res.size(); 277 TheSummary->set(Summary::MaxFunctionCount, PS.getMaxFunctionCount()); 278 TheSummary->set(Summary::MaxBlockCount, PS.getMaxCount()); 279 TheSummary->set(Summary::MaxInternalBlockCount, PS.getMaxInternalCount()); 280 TheSummary->set(Summary::TotalBlockCount, PS.getTotalCount()); 281 TheSummary->set(Summary::TotalNumBlocks, PS.getNumCounts()); 282 TheSummary->set(Summary::TotalNumFunctions, PS.getNumFunctions()); 283 for (unsigned I = 0; I < Res.size(); I++) 284 TheSummary->setEntry(I, Res[I]); 285 } 286 287 void InstrProfWriter::writeImpl(ProfOStream &OS) { 288 using namespace IndexedInstrProf; 289 290 OnDiskChainedHashTableGenerator<InstrProfRecordWriterTrait> Generator; 291 292 InstrProfSummaryBuilder ISB(ProfileSummaryBuilder::DefaultCutoffs); 293 InfoObj->SummaryBuilder = &ISB; 294 InstrProfSummaryBuilder CSISB(ProfileSummaryBuilder::DefaultCutoffs); 295 InfoObj->CSSummaryBuilder = &CSISB; 296 297 // Populate the hash table generator. 298 for (const auto &I : FunctionData) 299 if (shouldEncodeData(I.getValue())) 300 Generator.insert(I.getKey(), &I.getValue()); 301 // Write the header. 302 IndexedInstrProf::Header Header; 303 Header.Magic = IndexedInstrProf::Magic; 304 Header.Version = IndexedInstrProf::ProfVersion::CurrentVersion; 305 if (ProfileKind == PF_IRLevel) 306 Header.Version |= VARIANT_MASK_IR_PROF; 307 if (ProfileKind == PF_IRLevelWithCS) { 308 Header.Version |= VARIANT_MASK_IR_PROF; 309 Header.Version |= VARIANT_MASK_CSIR_PROF; 310 } 311 Header.Unused = 0; 312 Header.HashType = static_cast<uint64_t>(IndexedInstrProf::HashType); 313 Header.HashOffset = 0; 314 int N = sizeof(IndexedInstrProf::Header) / sizeof(uint64_t); 315 316 // Only write out all the fields except 'HashOffset'. We need 317 // to remember the offset of that field to allow back patching 318 // later. 319 for (int I = 0; I < N - 1; I++) 320 OS.write(reinterpret_cast<uint64_t *>(&Header)[I]); 321 322 // Save the location of Header.HashOffset field in \c OS. 323 uint64_t HashTableStartFieldOffset = OS.tell(); 324 // Reserve the space for HashOffset field. 325 OS.write(0); 326 327 // Reserve space to write profile summary data. 328 uint32_t NumEntries = ProfileSummaryBuilder::DefaultCutoffs.size(); 329 uint32_t SummarySize = Summary::getSize(Summary::NumKinds, NumEntries); 330 // Remember the summary offset. 331 uint64_t SummaryOffset = OS.tell(); 332 for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++) 333 OS.write(0); 334 uint64_t CSSummaryOffset = 0; 335 uint64_t CSSummarySize = 0; 336 if (ProfileKind == PF_IRLevelWithCS) { 337 CSSummaryOffset = OS.tell(); 338 CSSummarySize = SummarySize / sizeof(uint64_t); 339 for (unsigned I = 0; I < CSSummarySize; I++) 340 OS.write(0); 341 } 342 343 // Write the hash table. 344 uint64_t HashTableStart = Generator.Emit(OS.OS, *InfoObj); 345 346 // Allocate space for data to be serialized out. 347 std::unique_ptr<IndexedInstrProf::Summary> TheSummary = 348 IndexedInstrProf::allocSummary(SummarySize); 349 // Compute the Summary and copy the data to the data 350 // structure to be serialized out (to disk or buffer). 351 std::unique_ptr<ProfileSummary> PS = ISB.getSummary(); 352 setSummary(TheSummary.get(), *PS); 353 InfoObj->SummaryBuilder = nullptr; 354 355 // For Context Sensitive summary. 356 std::unique_ptr<IndexedInstrProf::Summary> TheCSSummary = nullptr; 357 if (ProfileKind == PF_IRLevelWithCS) { 358 TheCSSummary = IndexedInstrProf::allocSummary(SummarySize); 359 std::unique_ptr<ProfileSummary> CSPS = CSISB.getSummary(); 360 setSummary(TheCSSummary.get(), *CSPS); 361 } 362 InfoObj->CSSummaryBuilder = nullptr; 363 364 // Now do the final patch: 365 PatchItem PatchItems[] = { 366 // Patch the Header.HashOffset field. 367 {HashTableStartFieldOffset, &HashTableStart, 1}, 368 // Patch the summary data. 369 {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()), 370 (int)(SummarySize / sizeof(uint64_t))}, 371 {CSSummaryOffset, reinterpret_cast<uint64_t *>(TheCSSummary.get()), 372 (int)CSSummarySize}}; 373 374 OS.patch(PatchItems, sizeof(PatchItems) / sizeof(*PatchItems)); 375 } 376 377 void InstrProfWriter::write(raw_fd_ostream &OS) { 378 // Write the hash table. 379 ProfOStream POS(OS); 380 writeImpl(POS); 381 } 382 383 std::unique_ptr<MemoryBuffer> InstrProfWriter::writeBuffer() { 384 std::string Data; 385 raw_string_ostream OS(Data); 386 ProfOStream POS(OS); 387 // Write the hash table. 388 writeImpl(POS); 389 // Return this in an aligned memory buffer. 390 return MemoryBuffer::getMemBufferCopy(Data); 391 } 392 393 static const char *ValueProfKindStr[] = { 394 #define VALUE_PROF_KIND(Enumerator, Value, Descr) #Enumerator, 395 #include "llvm/ProfileData/InstrProfData.inc" 396 }; 397 398 void InstrProfWriter::writeRecordInText(StringRef Name, uint64_t Hash, 399 const InstrProfRecord &Func, 400 InstrProfSymtab &Symtab, 401 raw_fd_ostream &OS) { 402 OS << Name << "\n"; 403 OS << "# Func Hash:\n" << Hash << "\n"; 404 OS << "# Num Counters:\n" << Func.Counts.size() << "\n"; 405 OS << "# Counter Values:\n"; 406 for (uint64_t Count : Func.Counts) 407 OS << Count << "\n"; 408 409 uint32_t NumValueKinds = Func.getNumValueKinds(); 410 if (!NumValueKinds) { 411 OS << "\n"; 412 return; 413 } 414 415 OS << "# Num Value Kinds:\n" << Func.getNumValueKinds() << "\n"; 416 for (uint32_t VK = 0; VK < IPVK_Last + 1; VK++) { 417 uint32_t NS = Func.getNumValueSites(VK); 418 if (!NS) 419 continue; 420 OS << "# ValueKind = " << ValueProfKindStr[VK] << ":\n" << VK << "\n"; 421 OS << "# NumValueSites:\n" << NS << "\n"; 422 for (uint32_t S = 0; S < NS; S++) { 423 uint32_t ND = Func.getNumValueDataForSite(VK, S); 424 OS << ND << "\n"; 425 std::unique_ptr<InstrProfValueData[]> VD = Func.getValueForSite(VK, S); 426 for (uint32_t I = 0; I < ND; I++) { 427 if (VK == IPVK_IndirectCallTarget) 428 OS << Symtab.getFuncNameOrExternalSymbol(VD[I].Value) << ":" 429 << VD[I].Count << "\n"; 430 else 431 OS << VD[I].Value << ":" << VD[I].Count << "\n"; 432 } 433 } 434 } 435 436 OS << "\n"; 437 } 438 439 Error InstrProfWriter::writeText(raw_fd_ostream &OS) { 440 if (ProfileKind == PF_IRLevel) 441 OS << "# IR level Instrumentation Flag\n:ir\n"; 442 else if (ProfileKind == PF_IRLevelWithCS) 443 OS << "# CSIR level Instrumentation Flag\n:csir\n"; 444 InstrProfSymtab Symtab; 445 446 using FuncPair = detail::DenseMapPair<uint64_t, InstrProfRecord>; 447 using RecordType = std::pair<StringRef, FuncPair>; 448 SmallVector<RecordType, 4> OrderedFuncData; 449 450 for (const auto &I : FunctionData) { 451 if (shouldEncodeData(I.getValue())) { 452 if (Error E = Symtab.addFuncName(I.getKey())) 453 return E; 454 for (const auto &Func : I.getValue()) 455 OrderedFuncData.push_back(std::make_pair(I.getKey(), Func)); 456 } 457 } 458 459 llvm::sort(OrderedFuncData, [](const RecordType &A, const RecordType &B) { 460 return std::tie(A.first, A.second.first) < 461 std::tie(B.first, B.second.first); 462 }); 463 464 for (const auto &record : OrderedFuncData) { 465 const StringRef &Name = record.first; 466 const FuncPair &Func = record.second; 467 writeRecordInText(Name, Func.first, Func.second, Symtab, OS); 468 } 469 470 return Error::success(); 471 } 472