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/StringExtras.h" 17#include "llvm/Support/EndianStream.h" 18#include "llvm/Support/OnDiskHashTable.h" 19#include <tuple> 20 21using namespace llvm; 22 23namespace { 24static support::endianness ValueProfDataEndianness = support::little; 25 26class InstrProfRecordTrait { 27public: 28 typedef StringRef key_type; 29 typedef StringRef key_type_ref; 30 31 typedef const InstrProfWriter::ProfilingData *const data_type; 32 typedef const InstrProfWriter::ProfilingData *const data_type_ref; 33 34 typedef uint64_t hash_value_type; 35 typedef uint64_t offset_type; 36 37 static hash_value_type ComputeHash(key_type_ref K) { 38 return IndexedInstrProf::ComputeHash(K); 39 } 40 41 static std::pair<offset_type, offset_type> 42 EmitKeyDataLength(raw_ostream &Out, key_type_ref K, data_type_ref V) { 43 using namespace llvm::support; 44 endian::Writer<little> LE(Out); 45 46 offset_type N = K.size(); 47 LE.write<offset_type>(N); 48 49 offset_type M = 0; 50 for (const auto &ProfileData : *V) { 51 const InstrProfRecord &ProfRecord = ProfileData.second; 52 M += sizeof(uint64_t); // The function hash 53 M += sizeof(uint64_t); // The size of the Counts vector 54 M += ProfRecord.Counts.size() * sizeof(uint64_t); 55 56 // Value data 57 M += ValueProfData::getSize(ProfileData.second); 58 } 59 LE.write<offset_type>(M); 60 61 return std::make_pair(N, M); 62 } 63 64 static void EmitKey(raw_ostream &Out, key_type_ref K, offset_type N){ 65 Out.write(K.data(), N); 66 } 67 68 static void EmitData(raw_ostream &Out, key_type_ref, data_type_ref V, 69 offset_type) { 70 using namespace llvm::support; 71 endian::Writer<little> LE(Out); 72 for (const auto &ProfileData : *V) { 73 const InstrProfRecord &ProfRecord = ProfileData.second; 74 75 LE.write<uint64_t>(ProfileData.first); // Function hash 76 LE.write<uint64_t>(ProfRecord.Counts.size()); 77 for (uint64_t I : ProfRecord.Counts) 78 LE.write<uint64_t>(I); 79 80 // Write value data 81 std::unique_ptr<ValueProfData> VDataPtr = 82 ValueProfData::serializeFrom(ProfileData.second); 83 uint32_t S = VDataPtr->getSize(); 84 VDataPtr->swapBytesFromHost(ValueProfDataEndianness); 85 Out.write((const char *)VDataPtr.get(), S); 86 } 87 } 88}; 89} 90 91// Internal interface for testing purpose only. 92void InstrProfWriter::setValueProfDataEndianness( 93 support::endianness Endianness) { 94 ValueProfDataEndianness = Endianness; 95} 96 97std::error_code InstrProfWriter::addRecord(InstrProfRecord &&I, 98 uint64_t Weight) { 99 auto &ProfileDataMap = FunctionData[I.Name]; 100 101 bool NewFunc; 102 ProfilingData::iterator Where; 103 std::tie(Where, NewFunc) = 104 ProfileDataMap.insert(std::make_pair(I.Hash, InstrProfRecord())); 105 InstrProfRecord &Dest = Where->second; 106 107 instrprof_error Result = instrprof_error::success; 108 if (NewFunc) { 109 // We've never seen a function with this name and hash, add it. 110 Dest = std::move(I); 111 // Fix up the name to avoid dangling reference. 112 Dest.Name = FunctionData.find(Dest.Name)->getKey(); 113 if (Weight > 1) 114 Result = Dest.scale(Weight); 115 } else { 116 // We're updating a function we've seen before. 117 Result = Dest.merge(I, Weight); 118 } 119 120 Dest.sortValueData(); 121 122 // We keep track of the max function count as we go for simplicity. 123 // Update this statistic no matter the result of the merge. 124 if (Dest.Counts[0] > MaxFunctionCount) 125 MaxFunctionCount = Dest.Counts[0]; 126 127 return Result; 128} 129 130std::pair<uint64_t, uint64_t> InstrProfWriter::writeImpl(raw_ostream &OS) { 131 OnDiskChainedHashTableGenerator<InstrProfRecordTrait> Generator; 132 133 // Populate the hash table generator. 134 for (const auto &I : FunctionData) 135 Generator.insert(I.getKey(), &I.getValue()); 136 137 using namespace llvm::support; 138 endian::Writer<little> LE(OS); 139 140 // Write the header. 141 IndexedInstrProf::Header Header; 142 Header.Magic = IndexedInstrProf::Magic; 143 Header.Version = IndexedInstrProf::Version; 144 Header.MaxFunctionCount = MaxFunctionCount; 145 Header.HashType = static_cast<uint64_t>(IndexedInstrProf::HashType); 146 Header.HashOffset = 0; 147 int N = sizeof(IndexedInstrProf::Header) / sizeof(uint64_t); 148 149 // Only write out all the fields execpt 'HashOffset'. We need 150 // to remember the offset of that field to allow back patching 151 // later. 152 for (int I = 0; I < N - 1; I++) 153 LE.write<uint64_t>(reinterpret_cast<uint64_t *>(&Header)[I]); 154 155 // Save a space to write the hash table start location. 156 uint64_t HashTableStartLoc = OS.tell(); 157 // Reserve the space for HashOffset field. 158 LE.write<uint64_t>(0); 159 // Write the hash table. 160 uint64_t HashTableStart = Generator.Emit(OS); 161 162 return std::make_pair(HashTableStartLoc, HashTableStart); 163} 164 165void InstrProfWriter::write(raw_fd_ostream &OS) { 166 // Write the hash table. 167 auto TableStart = writeImpl(OS); 168 169 // Go back and fill in the hash table start. 170 using namespace support; 171 OS.seek(TableStart.first); 172 // Now patch the HashOffset field previously reserved. 173 endian::Writer<little>(OS).write<uint64_t>(TableStart.second); 174} 175 176static const char *ValueProfKindStr[] = { 177#define VALUE_PROF_KIND(Enumerator, Value) #Enumerator, 178#include "llvm/ProfileData/InstrProfData.inc" 179}; 180 181void InstrProfWriter::writeRecordInText(const InstrProfRecord &Func, 182 InstrProfSymtab &Symtab, 183 raw_fd_ostream &OS) { 184 OS << Func.Name << "\n"; 185 OS << "# Func Hash:\n" << Func.Hash << "\n"; 186 OS << "# Num Counters:\n" << Func.Counts.size() << "\n"; 187 OS << "# Counter Values:\n"; 188 for (uint64_t Count : Func.Counts) 189 OS << Count << "\n"; 190 191 uint32_t NumValueKinds = Func.getNumValueKinds(); 192 if (!NumValueKinds) { 193 OS << "\n"; 194 return; 195 } 196 197 OS << "# Num Value Kinds:\n" << Func.getNumValueKinds() << "\n"; 198 for (uint32_t VK = 0; VK < IPVK_Last + 1; VK++) { 199 uint32_t NS = Func.getNumValueSites(VK); 200 if (!NS) 201 continue; 202 OS << "# ValueKind = " << ValueProfKindStr[VK] << ":\n" << VK << "\n"; 203 OS << "# NumValueSites:\n" << NS << "\n"; 204 for (uint32_t S = 0; S < NS; S++) { 205 uint32_t ND = Func.getNumValueDataForSite(VK, S); 206 OS << ND << "\n"; 207 std::unique_ptr<InstrProfValueData[]> VD = Func.getValueForSite(VK, S); 208 for (uint32_t I = 0; I < ND; I++) { 209 if (VK == IPVK_IndirectCallTarget) 210 OS << Symtab.getFuncName(VD[I].Value) << ":" << VD[I].Count << "\n"; 211 else 212 OS << VD[I].Value << ":" << VD[I].Count << "\n"; 213 } 214 } 215 } 216 217 OS << "\n"; 218} 219 220void InstrProfWriter::writeText(raw_fd_ostream &OS) { 221 InstrProfSymtab Symtab; 222 for (const auto &I : FunctionData) 223 Symtab.addFuncName(I.getKey()); 224 Symtab.finalizeSymtab(); 225 226 for (const auto &I : FunctionData) 227 for (const auto &Func : I.getValue()) 228 writeRecordInText(Func.second, Symtab, OS); 229} 230 231std::unique_ptr<MemoryBuffer> InstrProfWriter::writeBuffer() { 232 std::string Data; 233 llvm::raw_string_ostream OS(Data); 234 // Write the hash table. 235 auto TableStart = writeImpl(OS); 236 OS.flush(); 237 238 // Go back and fill in the hash table start. 239 using namespace support; 240 uint64_t Bytes = endian::byte_swap<uint64_t, little>(TableStart.second); 241 Data.replace(TableStart.first, sizeof(uint64_t), (const char *)&Bytes, 242 sizeof(uint64_t)); 243 244 // Return this in an aligned memory buffer. 245 return MemoryBuffer::getMemBufferCopy(Data); 246} 247