1 //=-- SampleProf.h - Sampling profiling format support --------------------===// 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 common definitions used in the reading and writing of 11 // sample profile data. 12 // 13 //===----------------------------------------------------------------------===// 14 #ifndef LLVM_PROFILEDATA_SAMPLEPROF_H_ 15 #define LLVM_PROFILEDATA_SAMPLEPROF_H_ 16 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/ADT/SmallVector.h" 19 #include "llvm/ADT/StringMap.h" 20 #include "llvm/Support/Debug.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <system_error> 23 24 namespace llvm { 25 26 const std::error_category &sampleprof_category(); 27 28 enum class sampleprof_error { 29 success = 0, 30 bad_magic, 31 unsupported_version, 32 too_large, 33 truncated, 34 malformed, 35 unrecognized_format 36 }; 37 38 inline std::error_code make_error_code(sampleprof_error E) { 39 return std::error_code(static_cast<int>(E), sampleprof_category()); 40 } 41 42 } // end namespace llvm 43 44 namespace std { 45 template <> 46 struct is_error_code_enum<llvm::sampleprof_error> : std::true_type {}; 47 } 48 49 namespace llvm { 50 51 namespace sampleprof { 52 53 static inline uint64_t SPMagic() { 54 return uint64_t('S') << (64 - 8) | uint64_t('P') << (64 - 16) | 55 uint64_t('R') << (64 - 24) | uint64_t('O') << (64 - 32) | 56 uint64_t('F') << (64 - 40) | uint64_t('4') << (64 - 48) | 57 uint64_t('2') << (64 - 56) | uint64_t(0xff); 58 } 59 60 static inline uint64_t SPVersion() { return 100; } 61 62 /// \brief Represents the relative location of an instruction. 63 /// 64 /// Instruction locations are specified by the line offset from the 65 /// beginning of the function (marked by the line where the function 66 /// header is) and the discriminator value within that line. 67 /// 68 /// The discriminator value is useful to distinguish instructions 69 /// that are on the same line but belong to different basic blocks 70 /// (e.g., the two post-increment instructions in "if (p) x++; else y++;"). 71 struct LineLocation { 72 LineLocation(int L, unsigned D) : LineOffset(L), Discriminator(D) {} 73 int LineOffset; 74 unsigned Discriminator; 75 }; 76 77 } // End namespace sampleprof 78 79 template <> struct DenseMapInfo<sampleprof::LineLocation> { 80 typedef DenseMapInfo<int> OffsetInfo; 81 typedef DenseMapInfo<unsigned> DiscriminatorInfo; 82 static inline sampleprof::LineLocation getEmptyKey() { 83 return sampleprof::LineLocation(OffsetInfo::getEmptyKey(), 84 DiscriminatorInfo::getEmptyKey()); 85 } 86 static inline sampleprof::LineLocation getTombstoneKey() { 87 return sampleprof::LineLocation(OffsetInfo::getTombstoneKey(), 88 DiscriminatorInfo::getTombstoneKey()); 89 } 90 static inline unsigned getHashValue(sampleprof::LineLocation Val) { 91 return DenseMapInfo<std::pair<int, unsigned>>::getHashValue( 92 std::pair<int, unsigned>(Val.LineOffset, Val.Discriminator)); 93 } 94 static inline bool isEqual(sampleprof::LineLocation LHS, 95 sampleprof::LineLocation RHS) { 96 return LHS.LineOffset == RHS.LineOffset && 97 LHS.Discriminator == RHS.Discriminator; 98 } 99 }; 100 101 namespace sampleprof { 102 103 /// \brief Representation of a single sample record. 104 /// 105 /// A sample record is represented by a positive integer value, which 106 /// indicates how frequently was the associated line location executed. 107 /// 108 /// Additionally, if the associated location contains a function call, 109 /// the record will hold a list of all the possible called targets. For 110 /// direct calls, this will be the exact function being invoked. For 111 /// indirect calls (function pointers, virtual table dispatch), this 112 /// will be a list of one or more functions. 113 class SampleRecord { 114 public: 115 typedef StringMap<unsigned> CallTargetMap; 116 117 SampleRecord() : NumSamples(0), CallTargets() {} 118 119 /// \brief Increment the number of samples for this record by \p S. 120 /// 121 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping 122 /// around unsigned integers. 123 void addSamples(unsigned S) { 124 if (NumSamples <= std::numeric_limits<unsigned>::max() - S) 125 NumSamples += S; 126 else 127 NumSamples = std::numeric_limits<unsigned>::max(); 128 } 129 130 /// \brief Add called function \p F with samples \p S. 131 /// 132 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping 133 /// around unsigned integers. 134 void addCalledTarget(StringRef F, unsigned S) { 135 unsigned &TargetSamples = CallTargets[F]; 136 if (TargetSamples <= std::numeric_limits<unsigned>::max() - S) 137 TargetSamples += S; 138 else 139 TargetSamples = std::numeric_limits<unsigned>::max(); 140 } 141 142 /// \brief Return true if this sample record contains function calls. 143 bool hasCalls() const { return CallTargets.size() > 0; } 144 145 unsigned getSamples() const { return NumSamples; } 146 const CallTargetMap &getCallTargets() const { return CallTargets; } 147 148 /// \brief Merge the samples in \p Other into this record. 149 void merge(const SampleRecord &Other) { 150 addSamples(Other.getSamples()); 151 for (const auto &I : Other.getCallTargets()) 152 addCalledTarget(I.first(), I.second); 153 } 154 155 private: 156 unsigned NumSamples; 157 CallTargetMap CallTargets; 158 }; 159 160 typedef DenseMap<LineLocation, SampleRecord> BodySampleMap; 161 162 /// \brief Representation of the samples collected for a function. 163 /// 164 /// This data structure contains all the collected samples for the body 165 /// of a function. Each sample corresponds to a LineLocation instance 166 /// within the body of the function. 167 class FunctionSamples { 168 public: 169 FunctionSamples() : TotalSamples(0), TotalHeadSamples(0) {} 170 void print(raw_ostream &OS = dbgs()); 171 void addTotalSamples(unsigned Num) { TotalSamples += Num; } 172 void addHeadSamples(unsigned Num) { TotalHeadSamples += Num; } 173 void addBodySamples(int LineOffset, unsigned Discriminator, unsigned Num) { 174 assert(LineOffset >= 0); 175 // When dealing with instruction weights, we use the value 176 // zero to indicate the absence of a sample. If we read an 177 // actual zero from the profile file, use the value 1 to 178 // avoid the confusion later on. 179 if (Num == 0) 180 Num = 1; 181 BodySamples[LineLocation(LineOffset, Discriminator)].addSamples(Num); 182 } 183 void addCalledTargetSamples(int LineOffset, unsigned Discriminator, 184 std::string FName, unsigned Num) { 185 assert(LineOffset >= 0); 186 BodySamples[LineLocation(LineOffset, Discriminator)].addCalledTarget(FName, 187 Num); 188 } 189 190 /// \brief Return the sample record at the given location. 191 /// Each location is specified by \p LineOffset and \p Discriminator. 192 SampleRecord &sampleRecordAt(const LineLocation &Loc) { 193 return BodySamples[Loc]; 194 } 195 196 /// \brief Return the number of samples collected at the given location. 197 /// Each location is specified by \p LineOffset and \p Discriminator. 198 unsigned samplesAt(int LineOffset, unsigned Discriminator) { 199 return sampleRecordAt(LineLocation(LineOffset, Discriminator)).getSamples(); 200 } 201 202 bool empty() const { return BodySamples.empty(); } 203 204 /// \brief Return the total number of samples collected inside the function. 205 unsigned getTotalSamples() const { return TotalSamples; } 206 207 /// \brief Return the total number of samples collected at the head of the 208 /// function. 209 unsigned getHeadSamples() const { return TotalHeadSamples; } 210 211 /// \brief Return all the samples collected in the body of the function. 212 const BodySampleMap &getBodySamples() const { return BodySamples; } 213 214 /// \brief Merge the samples in \p Other into this one. 215 void merge(const FunctionSamples &Other) { 216 addTotalSamples(Other.getTotalSamples()); 217 addHeadSamples(Other.getHeadSamples()); 218 for (const auto &I : Other.getBodySamples()) { 219 const LineLocation &Loc = I.first; 220 const SampleRecord &Rec = I.second; 221 sampleRecordAt(Loc).merge(Rec); 222 } 223 } 224 225 private: 226 /// \brief Total number of samples collected inside this function. 227 /// 228 /// Samples are cumulative, they include all the samples collected 229 /// inside this function and all its inlined callees. 230 unsigned TotalSamples; 231 232 /// \brief Total number of samples collected at the head of the function. 233 unsigned TotalHeadSamples; 234 235 /// \brief Map instruction locations to collected samples. 236 /// 237 /// Each entry in this map contains the number of samples 238 /// collected at the corresponding line offset. All line locations 239 /// are an offset from the start of the function. 240 BodySampleMap BodySamples; 241 }; 242 243 } // End namespace sampleprof 244 245 } // End namespace llvm 246 247 #endif // LLVM_PROFILEDATA_SAMPLEPROF_H_ 248
