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, bool InstrEntryBBEnabled) 169 : Sparse(Sparse), InstrEntryBBEnabled(InstrEntryBBEnabled), 170 InfoObj(new InstrProfRecordWriterTrait()) {} 171 172 InstrProfWriter::~InstrProfWriter() { delete InfoObj; } 173 174 // Internal interface for testing purpose only. 175 void InstrProfWriter::setValueProfDataEndianness( 176 support::endianness Endianness) { 177 InfoObj->ValueProfDataEndianness = Endianness; 178 } 179 180 void InstrProfWriter::setOutputSparse(bool Sparse) { 181 this->Sparse = Sparse; 182 } 183 184 void InstrProfWriter::addRecord(NamedInstrProfRecord &&I, uint64_t Weight, 185 function_ref<void(Error)> Warn) { 186 auto Name = I.Name; 187 auto Hash = I.Hash; 188 addRecord(Name, Hash, std::move(I), Weight, Warn); 189 } 190 191 void InstrProfWriter::overlapRecord(NamedInstrProfRecord &&Other, 192 OverlapStats &Overlap, 193 OverlapStats &FuncLevelOverlap, 194 const OverlapFuncFilters &FuncFilter) { 195 auto Name = Other.Name; 196 auto Hash = Other.Hash; 197 Other.accumulateCounts(FuncLevelOverlap.Test); 198 if (FunctionData.find(Name) == FunctionData.end()) { 199 Overlap.addOneUnique(FuncLevelOverlap.Test); 200 return; 201 } 202 if (FuncLevelOverlap.Test.CountSum < 1.0f) { 203 Overlap.Overlap.NumEntries += 1; 204 return; 205 } 206 auto &ProfileDataMap = FunctionData[Name]; 207 bool NewFunc; 208 ProfilingData::iterator Where; 209 std::tie(Where, NewFunc) = 210 ProfileDataMap.insert(std::make_pair(Hash, InstrProfRecord())); 211 if (NewFunc) { 212 Overlap.addOneMismatch(FuncLevelOverlap.Test); 213 return; 214 } 215 InstrProfRecord &Dest = Where->second; 216 217 uint64_t ValueCutoff = FuncFilter.ValueCutoff; 218 if (!FuncFilter.NameFilter.empty() && Name.contains(FuncFilter.NameFilter)) 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, 1, 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 const 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 Error 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 if (InstrEntryBBEnabled) 312 Header.Version |= VARIANT_MASK_INSTR_ENTRY; 313 314 Header.Unused = 0; 315 Header.HashType = static_cast<uint64_t>(IndexedInstrProf::HashType); 316 Header.HashOffset = 0; 317 int N = sizeof(IndexedInstrProf::Header) / sizeof(uint64_t); 318 319 // Only write out all the fields except 'HashOffset'. We need 320 // to remember the offset of that field to allow back patching 321 // later. 322 for (int I = 0; I < N - 1; I++) 323 OS.write(reinterpret_cast<uint64_t *>(&Header)[I]); 324 325 // Save the location of Header.HashOffset field in \c OS. 326 uint64_t HashTableStartFieldOffset = OS.tell(); 327 // Reserve the space for HashOffset field. 328 OS.write(0); 329 330 // Reserve space to write profile summary data. 331 uint32_t NumEntries = ProfileSummaryBuilder::DefaultCutoffs.size(); 332 uint32_t SummarySize = Summary::getSize(Summary::NumKinds, NumEntries); 333 // Remember the summary offset. 334 uint64_t SummaryOffset = OS.tell(); 335 for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++) 336 OS.write(0); 337 uint64_t CSSummaryOffset = 0; 338 uint64_t CSSummarySize = 0; 339 if (ProfileKind == PF_IRLevelWithCS) { 340 CSSummaryOffset = OS.tell(); 341 CSSummarySize = SummarySize / sizeof(uint64_t); 342 for (unsigned I = 0; I < CSSummarySize; I++) 343 OS.write(0); 344 } 345 346 // Write the hash table. 347 uint64_t HashTableStart = Generator.Emit(OS.OS, *InfoObj); 348 349 // Allocate space for data to be serialized out. 350 std::unique_ptr<IndexedInstrProf::Summary> TheSummary = 351 IndexedInstrProf::allocSummary(SummarySize); 352 // Compute the Summary and copy the data to the data 353 // structure to be serialized out (to disk or buffer). 354 std::unique_ptr<ProfileSummary> PS = ISB.getSummary(); 355 setSummary(TheSummary.get(), *PS); 356 InfoObj->SummaryBuilder = nullptr; 357 358 // For Context Sensitive summary. 359 std::unique_ptr<IndexedInstrProf::Summary> TheCSSummary = nullptr; 360 if (ProfileKind == PF_IRLevelWithCS) { 361 TheCSSummary = IndexedInstrProf::allocSummary(SummarySize); 362 std::unique_ptr<ProfileSummary> CSPS = CSISB.getSummary(); 363 setSummary(TheCSSummary.get(), *CSPS); 364 } 365 InfoObj->CSSummaryBuilder = nullptr; 366 367 // Now do the final patch: 368 PatchItem PatchItems[] = { 369 // Patch the Header.HashOffset field. 370 {HashTableStartFieldOffset, &HashTableStart, 1}, 371 // Patch the summary data. 372 {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()), 373 (int)(SummarySize / sizeof(uint64_t))}, 374 {CSSummaryOffset, reinterpret_cast<uint64_t *>(TheCSSummary.get()), 375 (int)CSSummarySize}}; 376 377 OS.patch(PatchItems, sizeof(PatchItems) / sizeof(*PatchItems)); 378 379 for (const auto &I : FunctionData) 380 for (const auto &F : I.getValue()) 381 if (Error E = validateRecord(F.second)) 382 return E; 383 384 return Error::success(); 385 } 386 387 Error InstrProfWriter::write(raw_fd_ostream &OS) { 388 // Write the hash table. 389 ProfOStream POS(OS); 390 return writeImpl(POS); 391 } 392 393 std::unique_ptr<MemoryBuffer> InstrProfWriter::writeBuffer() { 394 std::string Data; 395 raw_string_ostream OS(Data); 396 ProfOStream POS(OS); 397 // Write the hash table. 398 if (Error E = writeImpl(POS)) 399 return nullptr; 400 // Return this in an aligned memory buffer. 401 return MemoryBuffer::getMemBufferCopy(Data); 402 } 403 404 static const char *ValueProfKindStr[] = { 405 #define VALUE_PROF_KIND(Enumerator, Value, Descr) #Enumerator, 406 #include "llvm/ProfileData/InstrProfData.inc" 407 }; 408 409 Error InstrProfWriter::validateRecord(const InstrProfRecord &Func) { 410 for (uint32_t VK = 0; VK <= IPVK_Last; VK++) { 411 uint32_t NS = Func.getNumValueSites(VK); 412 if (!NS) 413 continue; 414 for (uint32_t S = 0; S < NS; S++) { 415 uint32_t ND = Func.getNumValueDataForSite(VK, S); 416 std::unique_ptr<InstrProfValueData[]> VD = Func.getValueForSite(VK, S); 417 bool WasZero = false; 418 for (uint32_t I = 0; I < ND; I++) 419 if ((VK != IPVK_IndirectCallTarget) && (VD[I].Value == 0)) { 420 if (WasZero) 421 return make_error<InstrProfError>(instrprof_error::invalid_prof); 422 WasZero = true; 423 } 424 } 425 } 426 427 return Error::success(); 428 } 429 430 void InstrProfWriter::writeRecordInText(StringRef Name, uint64_t Hash, 431 const InstrProfRecord &Func, 432 InstrProfSymtab &Symtab, 433 raw_fd_ostream &OS) { 434 OS << Name << "\n"; 435 OS << "# Func Hash:\n" << Hash << "\n"; 436 OS << "# Num Counters:\n" << Func.Counts.size() << "\n"; 437 OS << "# Counter Values:\n"; 438 for (uint64_t Count : Func.Counts) 439 OS << Count << "\n"; 440 441 uint32_t NumValueKinds = Func.getNumValueKinds(); 442 if (!NumValueKinds) { 443 OS << "\n"; 444 return; 445 } 446 447 OS << "# Num Value Kinds:\n" << Func.getNumValueKinds() << "\n"; 448 for (uint32_t VK = 0; VK < IPVK_Last + 1; VK++) { 449 uint32_t NS = Func.getNumValueSites(VK); 450 if (!NS) 451 continue; 452 OS << "# ValueKind = " << ValueProfKindStr[VK] << ":\n" << VK << "\n"; 453 OS << "# NumValueSites:\n" << NS << "\n"; 454 for (uint32_t S = 0; S < NS; S++) { 455 uint32_t ND = Func.getNumValueDataForSite(VK, S); 456 OS << ND << "\n"; 457 std::unique_ptr<InstrProfValueData[]> VD = Func.getValueForSite(VK, S); 458 for (uint32_t I = 0; I < ND; I++) { 459 if (VK == IPVK_IndirectCallTarget) 460 OS << Symtab.getFuncNameOrExternalSymbol(VD[I].Value) << ":" 461 << VD[I].Count << "\n"; 462 else 463 OS << VD[I].Value << ":" << VD[I].Count << "\n"; 464 } 465 } 466 } 467 468 OS << "\n"; 469 } 470 471 Error InstrProfWriter::writeText(raw_fd_ostream &OS) { 472 if (ProfileKind == PF_IRLevel) 473 OS << "# IR level Instrumentation Flag\n:ir\n"; 474 else if (ProfileKind == PF_IRLevelWithCS) 475 OS << "# CSIR level Instrumentation Flag\n:csir\n"; 476 if (InstrEntryBBEnabled) 477 OS << "# Always instrument the function entry block\n:entry_first\n"; 478 InstrProfSymtab Symtab; 479 480 using FuncPair = detail::DenseMapPair<uint64_t, InstrProfRecord>; 481 using RecordType = std::pair<StringRef, FuncPair>; 482 SmallVector<RecordType, 4> OrderedFuncData; 483 484 for (const auto &I : FunctionData) { 485 if (shouldEncodeData(I.getValue())) { 486 if (Error E = Symtab.addFuncName(I.getKey())) 487 return E; 488 for (const auto &Func : I.getValue()) 489 OrderedFuncData.push_back(std::make_pair(I.getKey(), Func)); 490 } 491 } 492 493 llvm::sort(OrderedFuncData, [](const RecordType &A, const RecordType &B) { 494 return std::tie(A.first, A.second.first) < 495 std::tie(B.first, B.second.first); 496 }); 497 498 for (const auto &record : OrderedFuncData) { 499 const StringRef &Name = record.first; 500 const FuncPair &Func = record.second; 501 writeRecordInText(Name, Func.first, Func.second, Symtab, OS); 502 } 503 504 for (const auto &record : OrderedFuncData) { 505 const FuncPair &Func = record.second; 506 if (Error E = validateRecord(Func.second)) 507 return E; 508 } 509 510 return Error::success(); 511 } 512