1 //===- bolt/Profile/YAMLProfileWriter.cpp - YAML profile serializer -------===// 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 #include "bolt/Profile/YAMLProfileWriter.h" 10 #include "bolt/Core/BinaryBasicBlock.h" 11 #include "bolt/Core/BinaryFunction.h" 12 #include "bolt/Profile/BoltAddressTranslation.h" 13 #include "bolt/Profile/DataAggregator.h" 14 #include "bolt/Profile/ProfileReaderBase.h" 15 #include "bolt/Rewrite/RewriteInstance.h" 16 #include "llvm/Support/CommandLine.h" 17 #include "llvm/Support/FileSystem.h" 18 #include "llvm/Support/raw_ostream.h" 19 20 #undef DEBUG_TYPE 21 #define DEBUG_TYPE "bolt-prof" 22 23 namespace opts { 24 extern llvm::cl::opt<bool> ProfileUseDFS; 25 } // namespace opts 26 27 namespace llvm { 28 namespace bolt { 29 30 const BinaryFunction *YAMLProfileWriter::setCSIDestination( 31 const BinaryContext &BC, yaml::bolt::CallSiteInfo &CSI, 32 const MCSymbol *Symbol, const BoltAddressTranslation *BAT, 33 uint32_t Offset) { 34 CSI.DestId = 0; // designated for unknown functions 35 CSI.EntryDiscriminator = 0; 36 37 if (Symbol) { 38 uint64_t EntryID = 0; 39 if (const BinaryFunction *Callee = 40 BC.getFunctionForSymbol(Symbol, &EntryID)) { 41 if (BAT && BAT->isBATFunction(Callee->getAddress())) 42 std::tie(Callee, EntryID) = BAT->translateSymbol(BC, *Symbol, Offset); 43 else if (const BinaryBasicBlock *BB = 44 Callee->getBasicBlockContainingOffset(Offset)) 45 BC.getFunctionForSymbol(Callee->getSecondaryEntryPointSymbol(*BB), 46 &EntryID); 47 CSI.DestId = Callee->getFunctionNumber(); 48 CSI.EntryDiscriminator = EntryID; 49 return Callee; 50 } 51 } 52 return nullptr; 53 } 54 55 yaml::bolt::BinaryFunctionProfile 56 YAMLProfileWriter::convert(const BinaryFunction &BF, bool UseDFS, 57 const BoltAddressTranslation *BAT) { 58 yaml::bolt::BinaryFunctionProfile YamlBF; 59 const BinaryContext &BC = BF.getBinaryContext(); 60 61 const uint16_t LBRProfile = BF.getProfileFlags() & BinaryFunction::PF_LBR; 62 63 // Prepare function and block hashes 64 BF.computeHash(UseDFS); 65 BF.computeBlockHashes(); 66 67 YamlBF.Name = DataAggregator::getLocationName(BF, BAT); 68 YamlBF.Id = BF.getFunctionNumber(); 69 YamlBF.Hash = BF.getHash(); 70 YamlBF.NumBasicBlocks = BF.size(); 71 YamlBF.ExecCount = BF.getKnownExecutionCount(); 72 73 BinaryFunction::BasicBlockOrderType Order; 74 llvm::copy(UseDFS ? BF.dfs() : BF.getLayout().blocks(), 75 std::back_inserter(Order)); 76 77 for (const BinaryBasicBlock *BB : Order) { 78 yaml::bolt::BinaryBasicBlockProfile YamlBB; 79 YamlBB.Index = BB->getLayoutIndex(); 80 YamlBB.NumInstructions = BB->getNumNonPseudos(); 81 YamlBB.Hash = BB->getHash(); 82 83 if (!LBRProfile) { 84 YamlBB.EventCount = BB->getKnownExecutionCount(); 85 if (YamlBB.EventCount) 86 YamlBF.Blocks.emplace_back(YamlBB); 87 continue; 88 } 89 90 YamlBB.ExecCount = BB->getKnownExecutionCount(); 91 92 for (const MCInst &Instr : *BB) { 93 if (!BC.MIB->isCall(Instr) && !BC.MIB->isIndirectBranch(Instr)) 94 continue; 95 96 SmallVector<std::pair<StringRef, yaml::bolt::CallSiteInfo>> CSTargets; 97 yaml::bolt::CallSiteInfo CSI; 98 std::optional<uint32_t> Offset = BC.MIB->getOffset(Instr); 99 if (!Offset || *Offset < BB->getInputOffset()) 100 continue; 101 CSI.Offset = *Offset - BB->getInputOffset(); 102 103 if (BC.MIB->isIndirectCall(Instr) || BC.MIB->isIndirectBranch(Instr)) { 104 const auto ICSP = BC.MIB->tryGetAnnotationAs<IndirectCallSiteProfile>( 105 Instr, "CallProfile"); 106 if (!ICSP) 107 continue; 108 for (const IndirectCallProfile &CSP : ICSP.get()) { 109 StringRef TargetName = ""; 110 const BinaryFunction *Callee = 111 setCSIDestination(BC, CSI, CSP.Symbol, BAT); 112 if (Callee) 113 TargetName = Callee->getOneName(); 114 CSI.Count = CSP.Count; 115 CSI.Mispreds = CSP.Mispreds; 116 CSTargets.emplace_back(TargetName, CSI); 117 } 118 } else { // direct call or a tail call 119 StringRef TargetName = ""; 120 const MCSymbol *CalleeSymbol = BC.MIB->getTargetSymbol(Instr); 121 const BinaryFunction *const Callee = 122 setCSIDestination(BC, CSI, CalleeSymbol, BAT); 123 if (Callee) 124 TargetName = Callee->getOneName(); 125 126 auto getAnnotationWithDefault = [&](const MCInst &Inst, StringRef Ann) { 127 return BC.MIB->getAnnotationWithDefault(Instr, Ann, 0ull); 128 }; 129 if (BC.MIB->getConditionalTailCall(Instr)) { 130 CSI.Count = getAnnotationWithDefault(Instr, "CTCTakenCount"); 131 CSI.Mispreds = getAnnotationWithDefault(Instr, "CTCMispredCount"); 132 } else { 133 CSI.Count = getAnnotationWithDefault(Instr, "Count"); 134 } 135 136 if (CSI.Count) 137 CSTargets.emplace_back(TargetName, CSI); 138 } 139 // Sort targets in a similar way to getBranchData, see Location::operator< 140 llvm::sort(CSTargets, [](const auto &RHS, const auto &LHS) { 141 if (RHS.first != LHS.first) 142 return RHS.first < LHS.first; 143 return RHS.second.Offset < LHS.second.Offset; 144 }); 145 for (auto &KV : CSTargets) 146 YamlBB.CallSites.push_back(KV.second); 147 } 148 149 // Skip printing if there's no profile data for non-entry basic block. 150 // Include landing pads with non-zero execution count. 151 if (YamlBB.CallSites.empty() && !BB->isEntryPoint() && 152 !(BB->isLandingPad() && BB->getKnownExecutionCount() != 0)) { 153 // Include blocks having successors or predecessors with positive counts. 154 uint64_t SuccessorExecCount = 0; 155 for (const BinaryBasicBlock::BinaryBranchInfo &BranchInfo : 156 BB->branch_info()) 157 SuccessorExecCount += BranchInfo.Count; 158 uint64_t PredecessorExecCount = 0; 159 for (auto Pred : BB->predecessors()) 160 PredecessorExecCount += Pred->getBranchInfo(*BB).Count; 161 if (!SuccessorExecCount && !PredecessorExecCount) 162 continue; 163 } 164 165 auto BranchInfo = BB->branch_info_begin(); 166 for (const BinaryBasicBlock *Successor : BB->successors()) { 167 yaml::bolt::SuccessorInfo YamlSI; 168 YamlSI.Index = Successor->getLayoutIndex(); 169 YamlSI.Count = BranchInfo->Count; 170 YamlSI.Mispreds = BranchInfo->MispredictedCount; 171 172 YamlBB.Successors.emplace_back(YamlSI); 173 174 ++BranchInfo; 175 } 176 177 YamlBF.Blocks.emplace_back(YamlBB); 178 } 179 return YamlBF; 180 } 181 182 std::error_code YAMLProfileWriter::writeProfile(const RewriteInstance &RI) { 183 const BinaryContext &BC = RI.getBinaryContext(); 184 const auto &Functions = BC.getBinaryFunctions(); 185 186 std::error_code EC; 187 OS = std::make_unique<raw_fd_ostream>(Filename, EC, sys::fs::OF_None); 188 if (EC) { 189 errs() << "BOLT-WARNING: " << EC.message() << " : unable to open " 190 << Filename << " for output.\n"; 191 return EC; 192 } 193 194 yaml::bolt::BinaryProfile BP; 195 196 // Fill out the header info. 197 BP.Header.Version = 1; 198 BP.Header.FileName = std::string(BC.getFilename()); 199 std::optional<StringRef> BuildID = BC.getFileBuildID(); 200 BP.Header.Id = BuildID ? std::string(*BuildID) : "<unknown>"; 201 BP.Header.Origin = std::string(RI.getProfileReader()->getReaderName()); 202 BP.Header.IsDFSOrder = opts::ProfileUseDFS; 203 BP.Header.HashFunction = HashFunction::Default; 204 205 StringSet<> EventNames = RI.getProfileReader()->getEventNames(); 206 if (!EventNames.empty()) { 207 std::string Sep; 208 for (const StringMapEntry<std::nullopt_t> &EventEntry : EventNames) { 209 BP.Header.EventNames += Sep + EventEntry.first().str(); 210 Sep = ","; 211 } 212 } 213 214 // Make sure the profile is consistent across all functions. 215 uint16_t ProfileFlags = BinaryFunction::PF_NONE; 216 for (const auto &BFI : Functions) { 217 const BinaryFunction &BF = BFI.second; 218 if (BF.hasProfile() && !BF.empty()) { 219 assert(BF.getProfileFlags() != BinaryFunction::PF_NONE); 220 if (ProfileFlags == BinaryFunction::PF_NONE) 221 ProfileFlags = BF.getProfileFlags(); 222 223 assert(BF.getProfileFlags() == ProfileFlags && 224 "expected consistent profile flags across all functions"); 225 } 226 } 227 BP.Header.Flags = ProfileFlags; 228 229 // Add all function objects. 230 for (const auto &BFI : Functions) { 231 const BinaryFunction &BF = BFI.second; 232 if (BF.hasProfile()) { 233 if (!BF.hasValidProfile() && !RI.getProfileReader()->isTrustedSource()) 234 continue; 235 236 BP.Functions.emplace_back(convert(BF, opts::ProfileUseDFS)); 237 } 238 } 239 240 // Write the profile. 241 yaml::Output Out(*OS, nullptr, 0); 242 Out << BP; 243 244 return std::error_code(); 245 } 246 247 } // namespace bolt 248 } // namespace llvm 249