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      1 //===-- InstrProf.h - Instrumented profiling format support -----*- C++ -*-===//
      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 // Instrumentation-based profiling data is generated by instrumented
     11 // binaries through library functions in compiler-rt, and read by the clang
     12 // frontend to feed PGO.
     13 //
     14 //===----------------------------------------------------------------------===//
     15 
     16 #ifndef LLVM_PROFILEDATA_INSTRPROF_H
     17 #define LLVM_PROFILEDATA_INSTRPROF_H
     18 
     19 #include "llvm/ADT/STLExtras.h"
     20 #include "llvm/ADT/StringRef.h"
     21 #include "llvm/ADT/StringSet.h"
     22 #include "llvm/IR/GlobalValue.h"
     23 #include "llvm/IR/Metadata.h"
     24 #include "llvm/ProfileData/InstrProfData.inc"
     25 #include "llvm/ProfileData/ProfileCommon.h"
     26 #include "llvm/Support/Endian.h"
     27 #include "llvm/Support/ErrorHandling.h"
     28 #include "llvm/Support/MD5.h"
     29 #include "llvm/Support/MathExtras.h"
     30 #include <cstdint>
     31 #include <list>
     32 #include <system_error>
     33 #include <vector>
     34 
     35 namespace llvm {
     36 
     37 class Function;
     38 class GlobalVariable;
     39 class Module;
     40 
     41 /// Return the name of data section containing profile counter variables.
     42 inline StringRef getInstrProfCountersSectionName(bool AddSegment) {
     43   return AddSegment ? "__DATA," INSTR_PROF_CNTS_SECT_NAME_STR
     44                     : INSTR_PROF_CNTS_SECT_NAME_STR;
     45 }
     46 
     47 /// Return the name of data section containing names of instrumented
     48 /// functions.
     49 inline StringRef getInstrProfNameSectionName(bool AddSegment) {
     50   return AddSegment ? "__DATA," INSTR_PROF_NAME_SECT_NAME_STR
     51                     : INSTR_PROF_NAME_SECT_NAME_STR;
     52 }
     53 
     54 /// Return the name of the data section containing per-function control
     55 /// data.
     56 inline StringRef getInstrProfDataSectionName(bool AddSegment) {
     57   return AddSegment ? "__DATA," INSTR_PROF_DATA_SECT_NAME_STR
     58                     : INSTR_PROF_DATA_SECT_NAME_STR;
     59 }
     60 
     61 /// Return the name of data section containing pointers to value profile
     62 /// counters/nodes.
     63 inline StringRef getInstrProfValuesSectionName(bool AddSegment) {
     64   return AddSegment ? "__DATA," INSTR_PROF_VALS_SECT_NAME_STR
     65                     : INSTR_PROF_VALS_SECT_NAME_STR;
     66 }
     67 
     68 /// Return the name of data section containing nodes holdling value
     69 /// profiling data.
     70 inline StringRef getInstrProfVNodesSectionName(bool AddSegment) {
     71   return AddSegment ? "__DATA," INSTR_PROF_VNODES_SECT_NAME_STR
     72                     : INSTR_PROF_VNODES_SECT_NAME_STR;
     73 }
     74 
     75 /// Return the name profile runtime entry point to do value profiling
     76 /// for a given site.
     77 inline StringRef getInstrProfValueProfFuncName() {
     78   return INSTR_PROF_VALUE_PROF_FUNC_STR;
     79 }
     80 
     81 /// Return the name of the section containing function coverage mapping
     82 /// data.
     83 inline StringRef getInstrProfCoverageSectionName(bool AddSegment) {
     84   return AddSegment ? "__DATA," INSTR_PROF_COVMAP_SECT_NAME_STR
     85                     : INSTR_PROF_COVMAP_SECT_NAME_STR;
     86 }
     87 
     88 /// Return the name prefix of variables containing instrumented function names.
     89 inline StringRef getInstrProfNameVarPrefix() { return "__profn_"; }
     90 
     91 /// Return the name prefix of variables containing per-function control data.
     92 inline StringRef getInstrProfDataVarPrefix() { return "__profd_"; }
     93 
     94 /// Return the name prefix of profile counter variables.
     95 inline StringRef getInstrProfCountersVarPrefix() { return "__profc_"; }
     96 
     97 /// Return the name prefix of value profile variables.
     98 inline StringRef getInstrProfValuesVarPrefix() { return "__profvp_"; }
     99 
    100 /// Return the name of value profile node array variables:
    101 inline StringRef getInstrProfVNodesVarName() { return "__llvm_prf_vnodes"; }
    102 
    103 /// Return the name prefix of the COMDAT group for instrumentation variables
    104 /// associated with a COMDAT function.
    105 inline StringRef getInstrProfComdatPrefix() { return "__profv_"; }
    106 
    107 /// Return the name of the variable holding the strings (possibly compressed)
    108 /// of all function's PGO names.
    109 inline StringRef getInstrProfNamesVarName() {
    110   return "__llvm_prf_nm";
    111 }
    112 
    113 /// Return the name of a covarage mapping variable (internal linkage)
    114 /// for each instrumented source module. Such variables are allocated
    115 /// in the __llvm_covmap section.
    116 inline StringRef getCoverageMappingVarName() {
    117   return "__llvm_coverage_mapping";
    118 }
    119 
    120 /// Return the name of the internal variable recording the array
    121 /// of PGO name vars referenced by the coverage mapping. The owning
    122 /// functions of those names are not emitted by FE (e.g, unused inline
    123 /// functions.)
    124 inline StringRef getCoverageUnusedNamesVarName() {
    125   return "__llvm_coverage_names";
    126 }
    127 
    128 /// Return the name of function that registers all the per-function control
    129 /// data at program startup time by calling __llvm_register_function. This
    130 /// function has internal linkage and is called by  __llvm_profile_init
    131 /// runtime method. This function is not generated for these platforms:
    132 /// Darwin, Linux, and FreeBSD.
    133 inline StringRef getInstrProfRegFuncsName() {
    134   return "__llvm_profile_register_functions";
    135 }
    136 
    137 /// Return the name of the runtime interface that registers per-function control
    138 /// data for one instrumented function.
    139 inline StringRef getInstrProfRegFuncName() {
    140   return "__llvm_profile_register_function";
    141 }
    142 
    143 /// Return the name of the runtime interface that registers the PGO name strings.
    144 inline StringRef getInstrProfNamesRegFuncName() {
    145   return "__llvm_profile_register_names_function";
    146 }
    147 
    148 /// Return the name of the runtime initialization method that is generated by
    149 /// the compiler. The function calls __llvm_profile_register_functions and
    150 /// __llvm_profile_override_default_filename functions if needed. This function
    151 /// has internal linkage and invoked at startup time via init_array.
    152 inline StringRef getInstrProfInitFuncName() { return "__llvm_profile_init"; }
    153 
    154 /// Return the name of the hook variable defined in profile runtime library.
    155 /// A reference to the variable causes the linker to link in the runtime
    156 /// initialization module (which defines the hook variable).
    157 inline StringRef getInstrProfRuntimeHookVarName() {
    158   return "__llvm_profile_runtime";
    159 }
    160 
    161 /// Return the name of the compiler generated function that references the
    162 /// runtime hook variable. The function is a weak global.
    163 inline StringRef getInstrProfRuntimeHookVarUseFuncName() {
    164   return "__llvm_profile_runtime_user";
    165 }
    166 
    167 /// Return the name of the profile runtime interface that overrides the default
    168 /// profile data file name.
    169 inline StringRef getInstrProfFileOverriderFuncName() {
    170   return "__llvm_profile_override_default_filename";
    171 }
    172 
    173 /// Return the marker used to separate PGO names during serialization.
    174 inline StringRef getInstrProfNameSeparator() { return "\01"; }
    175 
    176 /// Return the modified name for function \c F suitable to be
    177 /// used the key for profile lookup. Variable \c InLTO indicates if this
    178 /// is called in LTO optimization passes.
    179 std::string getPGOFuncName(const Function &F, bool InLTO = false,
    180                            uint64_t Version = INSTR_PROF_INDEX_VERSION);
    181 
    182 /// Return the modified name for a function suitable to be
    183 /// used the key for profile lookup. The function's original
    184 /// name is \c RawFuncName and has linkage of type \c Linkage.
    185 /// The function is defined in module \c FileName.
    186 std::string getPGOFuncName(StringRef RawFuncName,
    187                            GlobalValue::LinkageTypes Linkage,
    188                            StringRef FileName,
    189                            uint64_t Version = INSTR_PROF_INDEX_VERSION);
    190 
    191 /// Return the name of the global variable used to store a function
    192 /// name in PGO instrumentation. \c FuncName is the name of the function
    193 /// returned by the \c getPGOFuncName call.
    194 std::string getPGOFuncNameVarName(StringRef FuncName,
    195                                   GlobalValue::LinkageTypes Linkage);
    196 
    197 /// Create and return the global variable for function name used in PGO
    198 /// instrumentation. \c FuncName is the name of the function returned
    199 /// by \c getPGOFuncName call.
    200 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName);
    201 
    202 /// Create and return the global variable for function name used in PGO
    203 /// instrumentation.  /// \c FuncName is the name of the function
    204 /// returned by \c getPGOFuncName call, \c M is the owning module,
    205 /// and \c Linkage is the linkage of the instrumented function.
    206 GlobalVariable *createPGOFuncNameVar(Module &M,
    207                                      GlobalValue::LinkageTypes Linkage,
    208                                      StringRef PGOFuncName);
    209 /// Return the initializer in string of the PGO name var \c NameVar.
    210 StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar);
    211 
    212 /// Given a PGO function name, remove the filename prefix and return
    213 /// the original (static) function name.
    214 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName,
    215                                    StringRef FileName = "<unknown>");
    216 
    217 /// Given a vector of strings (function PGO names) \c NameStrs, the
    218 /// method generates a combined string \c Result thatis ready to be
    219 /// serialized.  The \c Result string is comprised of three fields:
    220 /// The first field is the legnth of the uncompressed strings, and the
    221 /// the second field is the length of the zlib-compressed string.
    222 /// Both fields are encoded in ULEB128.  If \c doCompress is false, the
    223 ///  third field is the uncompressed strings; otherwise it is the
    224 /// compressed string. When the string compression is off, the
    225 /// second field will have value zero.
    226 Error collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
    227                                 bool doCompression, std::string &Result);
    228 /// Produce \c Result string with the same format described above. The input
    229 /// is vector of PGO function name variables that are referenced.
    230 Error collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
    231                                 std::string &Result, bool doCompression = true);
    232 class InstrProfSymtab;
    233 /// \c NameStrings is a string composed of one of more sub-strings encoded in
    234 /// the format described above. The substrings are seperated by 0 or more zero
    235 /// bytes. This method decodes the string and populates the \c Symtab.
    236 Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab);
    237 
    238 enum InstrProfValueKind : uint32_t {
    239 #define VALUE_PROF_KIND(Enumerator, Value) Enumerator = Value,
    240 #include "llvm/ProfileData/InstrProfData.inc"
    241 };
    242 
    243 struct InstrProfRecord;
    244 
    245 /// Get the value profile data for value site \p SiteIdx from \p InstrProfR
    246 /// and annotate the instruction \p Inst with the value profile meta data.
    247 /// Annotate up to \p MaxMDCount (default 3) number of records per value site.
    248 void annotateValueSite(Module &M, Instruction &Inst,
    249                        const InstrProfRecord &InstrProfR,
    250                        InstrProfValueKind ValueKind, uint32_t SiteIndx,
    251                        uint32_t MaxMDCount = 3);
    252 /// Same as the above interface but using an ArrayRef, as well as \p Sum.
    253 void annotateValueSite(Module &M, Instruction &Inst,
    254                        ArrayRef<InstrProfValueData> VDs,
    255                        uint64_t Sum, InstrProfValueKind ValueKind,
    256                        uint32_t MaxMDCount);
    257 
    258 /// Extract the value profile data from \p Inst which is annotated with
    259 /// value profile meta data. Return false if there is no value data annotated,
    260 /// otherwise  return true.
    261 bool getValueProfDataFromInst(const Instruction &Inst,
    262                               InstrProfValueKind ValueKind,
    263                               uint32_t MaxNumValueData,
    264                               InstrProfValueData ValueData[],
    265                               uint32_t &ActualNumValueData, uint64_t &TotalC);
    266 
    267 inline StringRef getPGOFuncNameMetadataName() { return "PGOFuncName"; }
    268 
    269 /// Return the PGOFuncName meta data associated with a function.
    270 MDNode *getPGOFuncNameMetadata(const Function &F);
    271 
    272 /// Create the PGOFuncName meta data if PGOFuncName is different from
    273 /// function's raw name. This should only apply to internal linkage functions
    274 /// declared by users only.
    275 void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName);
    276 
    277 const std::error_category &instrprof_category();
    278 
    279 enum class instrprof_error {
    280   success = 0,
    281   eof,
    282   unrecognized_format,
    283   bad_magic,
    284   bad_header,
    285   unsupported_version,
    286   unsupported_hash_type,
    287   too_large,
    288   truncated,
    289   malformed,
    290   unknown_function,
    291   hash_mismatch,
    292   count_mismatch,
    293   counter_overflow,
    294   value_site_count_mismatch,
    295   compress_failed,
    296   uncompress_failed
    297 };
    298 
    299 inline std::error_code make_error_code(instrprof_error E) {
    300   return std::error_code(static_cast<int>(E), instrprof_category());
    301 }
    302 
    303 class InstrProfError : public ErrorInfo<InstrProfError> {
    304 public:
    305   InstrProfError(instrprof_error Err) : Err(Err) {
    306     assert(Err != instrprof_error::success && "Not an error");
    307   }
    308 
    309   std::string message() const override;
    310 
    311   void log(raw_ostream &OS) const override { OS << message(); }
    312 
    313   std::error_code convertToErrorCode() const override {
    314     return make_error_code(Err);
    315   }
    316 
    317   instrprof_error get() const { return Err; }
    318 
    319   /// Consume an Error and return the raw enum value contained within it. The
    320   /// Error must either be a success value, or contain a single InstrProfError.
    321   static instrprof_error take(Error E) {
    322     auto Err = instrprof_error::success;
    323     handleAllErrors(std::move(E), [&Err](const InstrProfError &IPE) {
    324       assert(Err == instrprof_error::success && "Multiple errors encountered");
    325       Err = IPE.get();
    326     });
    327     return Err;
    328   }
    329 
    330   static char ID;
    331 
    332 private:
    333   instrprof_error Err;
    334 };
    335 
    336 class SoftInstrProfErrors {
    337   /// Count the number of soft instrprof_errors encountered and keep track of
    338   /// the first such error for reporting purposes.
    339 
    340   /// The first soft error encountered.
    341   instrprof_error FirstError;
    342 
    343   /// The number of hash mismatches.
    344   unsigned NumHashMismatches;
    345 
    346   /// The number of count mismatches.
    347   unsigned NumCountMismatches;
    348 
    349   /// The number of counter overflows.
    350   unsigned NumCounterOverflows;
    351 
    352   /// The number of value site count mismatches.
    353   unsigned NumValueSiteCountMismatches;
    354 
    355 public:
    356   SoftInstrProfErrors()
    357       : FirstError(instrprof_error::success), NumHashMismatches(0),
    358         NumCountMismatches(0), NumCounterOverflows(0),
    359         NumValueSiteCountMismatches(0) {}
    360 
    361   ~SoftInstrProfErrors() {
    362     assert(FirstError == instrprof_error::success &&
    363            "Unchecked soft error encountered");
    364   }
    365 
    366   /// Track a soft error (\p IE) and increment its associated counter.
    367   void addError(instrprof_error IE);
    368 
    369   /// Get the number of hash mismatches.
    370   unsigned getNumHashMismatches() const { return NumHashMismatches; }
    371 
    372   /// Get the number of count mismatches.
    373   unsigned getNumCountMismatches() const { return NumCountMismatches; }
    374 
    375   /// Get the number of counter overflows.
    376   unsigned getNumCounterOverflows() const { return NumCounterOverflows; }
    377 
    378   /// Get the number of value site count mismatches.
    379   unsigned getNumValueSiteCountMismatches() const {
    380     return NumValueSiteCountMismatches;
    381   }
    382 
    383   /// Return the first encountered error and reset FirstError to a success
    384   /// value.
    385   Error takeError() {
    386     if (FirstError == instrprof_error::success)
    387       return Error::success();
    388     auto E = make_error<InstrProfError>(FirstError);
    389     FirstError = instrprof_error::success;
    390     return E;
    391   }
    392 };
    393 
    394 namespace object {
    395 class SectionRef;
    396 }
    397 
    398 namespace IndexedInstrProf {
    399 uint64_t ComputeHash(StringRef K);
    400 }
    401 
    402 /// A symbol table used for function PGO name look-up with keys
    403 /// (such as pointers, md5hash values) to the function. A function's
    404 /// PGO name or name's md5hash are used in retrieving the profile
    405 /// data of the function. See \c getPGOFuncName() method for details
    406 /// on how PGO name is formed.
    407 class InstrProfSymtab {
    408 public:
    409   typedef std::vector<std::pair<uint64_t, uint64_t>> AddrHashMap;
    410 
    411 private:
    412   StringRef Data;
    413   uint64_t Address;
    414   // Unique name strings.
    415   StringSet<> NameTab;
    416   // A map from MD5 keys to function name strings.
    417   std::vector<std::pair<uint64_t, StringRef>> MD5NameMap;
    418   // A map from MD5 keys to function define. We only populate this map
    419   // when build the Symtab from a Module.
    420   std::vector<std::pair<uint64_t, Function *>> MD5FuncMap;
    421   // A map from function runtime address to function name MD5 hash.
    422   // This map is only populated and used by raw instr profile reader.
    423   AddrHashMap AddrToMD5Map;
    424 
    425 public:
    426   InstrProfSymtab()
    427       : Data(), Address(0), NameTab(), MD5NameMap(), MD5FuncMap(),
    428       AddrToMD5Map() {}
    429 
    430   /// Create InstrProfSymtab from an object file section which
    431   /// contains function PGO names. When section may contain raw
    432   /// string data or string data in compressed form. This method
    433   /// only initialize the symtab with reference to the data and
    434   /// the section base address. The decompression will be delayed
    435   /// until before it is used. See also \c create(StringRef) method.
    436   Error create(object::SectionRef &Section);
    437   /// This interface is used by reader of CoverageMapping test
    438   /// format.
    439   inline Error create(StringRef D, uint64_t BaseAddr);
    440   /// \c NameStrings is a string composed of one of more sub-strings
    441   ///  encoded in the format described in \c collectPGOFuncNameStrings.
    442   /// This method is a wrapper to \c readPGOFuncNameStrings method.
    443   inline Error create(StringRef NameStrings);
    444   /// A wrapper interface to populate the PGO symtab with functions
    445   /// decls from module \c M. This interface is used by transformation
    446   /// passes such as indirect function call promotion. Variable \c InLTO
    447   /// indicates if this is called from LTO optimization passes.
    448   void create(Module &M, bool InLTO = false);
    449   /// Create InstrProfSymtab from a set of names iteratable from
    450   /// \p IterRange. This interface is used by IndexedProfReader.
    451   template <typename NameIterRange> void create(const NameIterRange &IterRange);
    452   // If the symtab is created by a series of calls to \c addFuncName, \c
    453   // finalizeSymtab needs to be called before looking up function names.
    454   // This is required because the underlying map is a vector (for space
    455   // efficiency) which needs to be sorted.
    456   inline void finalizeSymtab();
    457   /// Update the symtab by adding \p FuncName to the table. This interface
    458   /// is used by the raw and text profile readers.
    459   void addFuncName(StringRef FuncName) {
    460     auto Ins = NameTab.insert(FuncName);
    461     if (Ins.second)
    462       MD5NameMap.push_back(std::make_pair(
    463           IndexedInstrProf::ComputeHash(FuncName), Ins.first->getKey()));
    464   }
    465   /// Map a function address to its name's MD5 hash. This interface
    466   /// is only used by the raw profiler reader.
    467   void mapAddress(uint64_t Addr, uint64_t MD5Val) {
    468     AddrToMD5Map.push_back(std::make_pair(Addr, MD5Val));
    469   }
    470   AddrHashMap &getAddrHashMap() { return AddrToMD5Map; }
    471   /// Return function's PGO name from the function name's symbol
    472   /// address in the object file. If an error occurs, return
    473   /// an empty string.
    474   StringRef getFuncName(uint64_t FuncNameAddress, size_t NameSize);
    475   /// Return function's PGO name from the name's md5 hash value.
    476   /// If not found, return an empty string.
    477   inline StringRef getFuncName(uint64_t FuncMD5Hash);
    478   /// Return function from the name's md5 hash. Return nullptr if not found.
    479   inline Function *getFunction(uint64_t FuncMD5Hash);
    480   /// Return the function's original assembly name by stripping off
    481   /// the prefix attached (to symbols with priviate linkage). For
    482   /// global functions, it returns the same string as getFuncName.
    483   inline StringRef getOrigFuncName(uint64_t FuncMD5Hash);
    484   /// Return the name section data.
    485   inline StringRef getNameData() const { return Data; }
    486 };
    487 
    488 Error InstrProfSymtab::create(StringRef D, uint64_t BaseAddr) {
    489   Data = D;
    490   Address = BaseAddr;
    491   return Error::success();
    492 }
    493 
    494 Error InstrProfSymtab::create(StringRef NameStrings) {
    495   return readPGOFuncNameStrings(NameStrings, *this);
    496 }
    497 
    498 template <typename NameIterRange>
    499 void InstrProfSymtab::create(const NameIterRange &IterRange) {
    500   for (auto Name : IterRange)
    501     addFuncName(Name);
    502 
    503   finalizeSymtab();
    504 }
    505 
    506 void InstrProfSymtab::finalizeSymtab() {
    507   std::sort(MD5NameMap.begin(), MD5NameMap.end(), less_first());
    508   std::sort(MD5FuncMap.begin(), MD5FuncMap.end(), less_first());
    509   std::sort(AddrToMD5Map.begin(), AddrToMD5Map.end(), less_first());
    510   AddrToMD5Map.erase(std::unique(AddrToMD5Map.begin(), AddrToMD5Map.end()),
    511                      AddrToMD5Map.end());
    512 }
    513 
    514 StringRef InstrProfSymtab::getFuncName(uint64_t FuncMD5Hash) {
    515   auto Result =
    516       std::lower_bound(MD5NameMap.begin(), MD5NameMap.end(), FuncMD5Hash,
    517                        [](const std::pair<uint64_t, std::string> &LHS,
    518                           uint64_t RHS) { return LHS.first < RHS; });
    519   if (Result != MD5NameMap.end() && Result->first == FuncMD5Hash)
    520     return Result->second;
    521   return StringRef();
    522 }
    523 
    524 Function* InstrProfSymtab::getFunction(uint64_t FuncMD5Hash) {
    525   auto Result =
    526       std::lower_bound(MD5FuncMap.begin(), MD5FuncMap.end(), FuncMD5Hash,
    527                        [](const std::pair<uint64_t, Function*> &LHS,
    528                           uint64_t RHS) { return LHS.first < RHS; });
    529   if (Result != MD5FuncMap.end() && Result->first == FuncMD5Hash)
    530     return Result->second;
    531   return nullptr;
    532 }
    533 
    534 // See also getPGOFuncName implementation. These two need to be
    535 // matched.
    536 StringRef InstrProfSymtab::getOrigFuncName(uint64_t FuncMD5Hash) {
    537   StringRef PGOName = getFuncName(FuncMD5Hash);
    538   size_t S = PGOName.find_first_of(':');
    539   if (S == StringRef::npos)
    540     return PGOName;
    541   return PGOName.drop_front(S + 1);
    542 }
    543 
    544 struct InstrProfValueSiteRecord {
    545   /// Value profiling data pairs at a given value site.
    546   std::list<InstrProfValueData> ValueData;
    547 
    548   InstrProfValueSiteRecord() { ValueData.clear(); }
    549   template <class InputIterator>
    550   InstrProfValueSiteRecord(InputIterator F, InputIterator L)
    551       : ValueData(F, L) {}
    552 
    553   /// Sort ValueData ascending by Value
    554   void sortByTargetValues() {
    555     ValueData.sort(
    556         [](const InstrProfValueData &left, const InstrProfValueData &right) {
    557           return left.Value < right.Value;
    558         });
    559   }
    560   /// Sort ValueData Descending by Count
    561   inline void sortByCount();
    562 
    563   /// Merge data from another InstrProfValueSiteRecord
    564   /// Optionally scale merged counts by \p Weight.
    565   void merge(SoftInstrProfErrors &SIPE, InstrProfValueSiteRecord &Input,
    566              uint64_t Weight = 1);
    567   /// Scale up value profile data counts.
    568   void scale(SoftInstrProfErrors &SIPE, uint64_t Weight);
    569 };
    570 
    571 /// Profiling information for a single function.
    572 struct InstrProfRecord {
    573   InstrProfRecord() : SIPE() {}
    574   InstrProfRecord(StringRef Name, uint64_t Hash, std::vector<uint64_t> Counts)
    575       : Name(Name), Hash(Hash), Counts(std::move(Counts)), SIPE() {}
    576   StringRef Name;
    577   uint64_t Hash;
    578   std::vector<uint64_t> Counts;
    579   SoftInstrProfErrors SIPE;
    580 
    581   typedef std::vector<std::pair<uint64_t, uint64_t>> ValueMapType;
    582 
    583   /// Return the number of value profile kinds with non-zero number
    584   /// of profile sites.
    585   inline uint32_t getNumValueKinds() const;
    586   /// Return the number of instrumented sites for ValueKind.
    587   inline uint32_t getNumValueSites(uint32_t ValueKind) const;
    588   /// Return the total number of ValueData for ValueKind.
    589   inline uint32_t getNumValueData(uint32_t ValueKind) const;
    590   /// Return the number of value data collected for ValueKind at profiling
    591   /// site: Site.
    592   inline uint32_t getNumValueDataForSite(uint32_t ValueKind,
    593                                          uint32_t Site) const;
    594   /// Return the array of profiled values at \p Site. If \p TotalC
    595   /// is not null, the total count of all target values at this site
    596   /// will be stored in \c *TotalC.
    597   inline std::unique_ptr<InstrProfValueData[]>
    598   getValueForSite(uint32_t ValueKind, uint32_t Site,
    599                   uint64_t *TotalC = 0) const;
    600   /// Get the target value/counts of kind \p ValueKind collected at site
    601   /// \p Site and store the result in array \p Dest. Return the total
    602   /// counts of all target values at this site.
    603   inline uint64_t getValueForSite(InstrProfValueData Dest[], uint32_t ValueKind,
    604                                   uint32_t Site) const;
    605   /// Reserve space for NumValueSites sites.
    606   inline void reserveSites(uint32_t ValueKind, uint32_t NumValueSites);
    607   /// Add ValueData for ValueKind at value Site.
    608   void addValueData(uint32_t ValueKind, uint32_t Site,
    609                     InstrProfValueData *VData, uint32_t N,
    610                     ValueMapType *ValueMap);
    611 
    612   /// Merge the counts in \p Other into this one.
    613   /// Optionally scale merged counts by \p Weight.
    614   void merge(InstrProfRecord &Other, uint64_t Weight = 1);
    615 
    616   /// Scale up profile counts (including value profile data) by
    617   /// \p Weight.
    618   void scale(uint64_t Weight);
    619 
    620   /// Sort value profile data (per site) by count.
    621   void sortValueData() {
    622     for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind) {
    623       std::vector<InstrProfValueSiteRecord> &SiteRecords =
    624           getValueSitesForKind(Kind);
    625       for (auto &SR : SiteRecords)
    626         SR.sortByCount();
    627     }
    628   }
    629   /// Clear value data entries
    630   void clearValueData() {
    631     for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
    632       getValueSitesForKind(Kind).clear();
    633   }
    634 
    635   /// Get the error contained within the record's soft error counter.
    636   Error takeError() { return SIPE.takeError(); }
    637 
    638 private:
    639   std::vector<InstrProfValueSiteRecord> IndirectCallSites;
    640   const std::vector<InstrProfValueSiteRecord> &
    641   getValueSitesForKind(uint32_t ValueKind) const {
    642     switch (ValueKind) {
    643     case IPVK_IndirectCallTarget:
    644       return IndirectCallSites;
    645     default:
    646       llvm_unreachable("Unknown value kind!");
    647     }
    648     return IndirectCallSites;
    649   }
    650 
    651   std::vector<InstrProfValueSiteRecord> &
    652   getValueSitesForKind(uint32_t ValueKind) {
    653     return const_cast<std::vector<InstrProfValueSiteRecord> &>(
    654         const_cast<const InstrProfRecord *>(this)
    655             ->getValueSitesForKind(ValueKind));
    656   }
    657 
    658   // Map indirect call target name hash to name string.
    659   uint64_t remapValue(uint64_t Value, uint32_t ValueKind,
    660                       ValueMapType *HashKeys);
    661 
    662   // Merge Value Profile data from Src record to this record for ValueKind.
    663   // Scale merged value counts by \p Weight.
    664   void mergeValueProfData(uint32_t ValueKind, InstrProfRecord &Src,
    665                           uint64_t Weight);
    666   // Scale up value profile data count.
    667   void scaleValueProfData(uint32_t ValueKind, uint64_t Weight);
    668 };
    669 
    670 uint32_t InstrProfRecord::getNumValueKinds() const {
    671   uint32_t NumValueKinds = 0;
    672   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
    673     NumValueKinds += !(getValueSitesForKind(Kind).empty());
    674   return NumValueKinds;
    675 }
    676 
    677 uint32_t InstrProfRecord::getNumValueData(uint32_t ValueKind) const {
    678   uint32_t N = 0;
    679   const std::vector<InstrProfValueSiteRecord> &SiteRecords =
    680       getValueSitesForKind(ValueKind);
    681   for (auto &SR : SiteRecords) {
    682     N += SR.ValueData.size();
    683   }
    684   return N;
    685 }
    686 
    687 uint32_t InstrProfRecord::getNumValueSites(uint32_t ValueKind) const {
    688   return getValueSitesForKind(ValueKind).size();
    689 }
    690 
    691 uint32_t InstrProfRecord::getNumValueDataForSite(uint32_t ValueKind,
    692                                                  uint32_t Site) const {
    693   return getValueSitesForKind(ValueKind)[Site].ValueData.size();
    694 }
    695 
    696 std::unique_ptr<InstrProfValueData[]>
    697 InstrProfRecord::getValueForSite(uint32_t ValueKind, uint32_t Site,
    698                                  uint64_t *TotalC) const {
    699   uint64_t Dummy;
    700   uint64_t &TotalCount = (TotalC == 0 ? Dummy : *TotalC);
    701   uint32_t N = getNumValueDataForSite(ValueKind, Site);
    702   if (N == 0) {
    703     TotalCount = 0;
    704     return std::unique_ptr<InstrProfValueData[]>(nullptr);
    705   }
    706 
    707   auto VD = llvm::make_unique<InstrProfValueData[]>(N);
    708   TotalCount = getValueForSite(VD.get(), ValueKind, Site);
    709 
    710   return VD;
    711 }
    712 
    713 uint64_t InstrProfRecord::getValueForSite(InstrProfValueData Dest[],
    714                                           uint32_t ValueKind,
    715                                           uint32_t Site) const {
    716   uint32_t I = 0;
    717   uint64_t TotalCount = 0;
    718   for (auto V : getValueSitesForKind(ValueKind)[Site].ValueData) {
    719     Dest[I].Value = V.Value;
    720     Dest[I].Count = V.Count;
    721     TotalCount = SaturatingAdd(TotalCount, V.Count);
    722     I++;
    723   }
    724   return TotalCount;
    725 }
    726 
    727 void InstrProfRecord::reserveSites(uint32_t ValueKind, uint32_t NumValueSites) {
    728   std::vector<InstrProfValueSiteRecord> &ValueSites =
    729       getValueSitesForKind(ValueKind);
    730   ValueSites.reserve(NumValueSites);
    731 }
    732 
    733 inline support::endianness getHostEndianness() {
    734   return sys::IsLittleEndianHost ? support::little : support::big;
    735 }
    736 
    737 // Include definitions for value profile data
    738 #define INSTR_PROF_VALUE_PROF_DATA
    739 #include "llvm/ProfileData/InstrProfData.inc"
    740 
    741 void InstrProfValueSiteRecord::sortByCount() {
    742   ValueData.sort(
    743       [](const InstrProfValueData &left, const InstrProfValueData &right) {
    744         return left.Count > right.Count;
    745       });
    746   // Now truncate
    747   size_t max_s = INSTR_PROF_MAX_NUM_VAL_PER_SITE;
    748   if (ValueData.size() > max_s)
    749     ValueData.resize(max_s);
    750 }
    751 
    752 namespace IndexedInstrProf {
    753 
    754 enum class HashT : uint32_t {
    755   MD5,
    756 
    757   Last = MD5
    758 };
    759 
    760 inline uint64_t ComputeHash(HashT Type, StringRef K) {
    761   switch (Type) {
    762   case HashT::MD5:
    763     return MD5Hash(K);
    764   }
    765   llvm_unreachable("Unhandled hash type");
    766 }
    767 
    768 const uint64_t Magic = 0x8169666f72706cff; // "\xfflprofi\x81"
    769 
    770 enum ProfVersion {
    771   // Version 1 is the first version. In this version, the value of
    772   // a key/value pair can only include profile data of a single function.
    773   // Due to this restriction, the number of block counters for a given
    774   // function is not recorded but derived from the length of the value.
    775   Version1 = 1,
    776   // The version 2 format supports recording profile data of multiple
    777   // functions which share the same key in one value field. To support this,
    778   // the number block counters is recorded as an uint64_t field right after the
    779   // function structural hash.
    780   Version2 = 2,
    781   // Version 3 supports value profile data. The value profile data is expected
    782   // to follow the block counter profile data.
    783   Version3 = 3,
    784   // In this version, profile summary data \c IndexedInstrProf::Summary is
    785   // stored after the profile header.
    786   Version4 = 4,
    787   // The current version is 4.
    788   CurrentVersion = INSTR_PROF_INDEX_VERSION
    789 };
    790 const uint64_t Version = ProfVersion::CurrentVersion;
    791 
    792 const HashT HashType = HashT::MD5;
    793 
    794 inline uint64_t ComputeHash(StringRef K) { return ComputeHash(HashType, K); }
    795 
    796 // This structure defines the file header of the LLVM profile
    797 // data file in indexed-format.
    798 struct Header {
    799   uint64_t Magic;
    800   uint64_t Version;
    801   uint64_t Unused; // Becomes unused since version 4
    802   uint64_t HashType;
    803   uint64_t HashOffset;
    804 };
    805 
    806 // Profile summary data recorded in the profile data file in indexed
    807 // format. It is introduced in version 4. The summary data follows
    808 // right after the profile file header.
    809 struct Summary {
    810 
    811   struct Entry {
    812     uint64_t Cutoff; ///< The required percentile of total execution count.
    813     uint64_t
    814         MinBlockCount;  ///< The minimum execution count for this percentile.
    815     uint64_t NumBlocks; ///< Number of blocks >= the minumum execution count.
    816   };
    817   // The field kind enumerator to assigned value mapping should remain
    818   // unchanged  when a new kind is added or an old kind gets deleted in
    819   // the future.
    820   enum SummaryFieldKind {
    821     /// The total number of functions instrumented.
    822     TotalNumFunctions = 0,
    823     /// Total number of instrumented blocks/edges.
    824     TotalNumBlocks = 1,
    825     /// The maximal execution count among all functions.
    826     /// This field does not exist for profile data from IR based
    827     /// instrumentation.
    828     MaxFunctionCount = 2,
    829     /// Max block count of the program.
    830     MaxBlockCount = 3,
    831     /// Max internal block count of the program (excluding entry blocks).
    832     MaxInternalBlockCount = 4,
    833     /// The sum of all instrumented block counts.
    834     TotalBlockCount = 5,
    835     NumKinds = TotalBlockCount + 1
    836   };
    837 
    838   // The number of summmary fields following the summary header.
    839   uint64_t NumSummaryFields;
    840   // The number of Cutoff Entries (Summary::Entry) following summary fields.
    841   uint64_t NumCutoffEntries;
    842 
    843   static uint32_t getSize(uint32_t NumSumFields, uint32_t NumCutoffEntries) {
    844     return sizeof(Summary) + NumCutoffEntries * sizeof(Entry) +
    845            NumSumFields * sizeof(uint64_t);
    846   }
    847 
    848   const uint64_t *getSummaryDataBase() const {
    849     return reinterpret_cast<const uint64_t *>(this + 1);
    850   }
    851   uint64_t *getSummaryDataBase() {
    852     return reinterpret_cast<uint64_t *>(this + 1);
    853   }
    854   const Entry *getCutoffEntryBase() const {
    855     return reinterpret_cast<const Entry *>(
    856         &getSummaryDataBase()[NumSummaryFields]);
    857   }
    858   Entry *getCutoffEntryBase() {
    859     return reinterpret_cast<Entry *>(&getSummaryDataBase()[NumSummaryFields]);
    860   }
    861 
    862   uint64_t get(SummaryFieldKind K) const {
    863     return getSummaryDataBase()[K];
    864   }
    865 
    866   void set(SummaryFieldKind K, uint64_t V) {
    867     getSummaryDataBase()[K] = V;
    868   }
    869 
    870   const Entry &getEntry(uint32_t I) const { return getCutoffEntryBase()[I]; }
    871   void setEntry(uint32_t I, const ProfileSummaryEntry &E) {
    872     Entry &ER = getCutoffEntryBase()[I];
    873     ER.Cutoff = E.Cutoff;
    874     ER.MinBlockCount = E.MinCount;
    875     ER.NumBlocks = E.NumCounts;
    876   }
    877 
    878   Summary(uint32_t Size) { memset(this, 0, Size); }
    879   void operator delete(void *ptr) { ::operator delete(ptr); }
    880 
    881   Summary() = delete;
    882 };
    883 
    884 inline std::unique_ptr<Summary> allocSummary(uint32_t TotalSize) {
    885   return std::unique_ptr<Summary>(new (::operator new(TotalSize))
    886                                       Summary(TotalSize));
    887 }
    888 } // end namespace IndexedInstrProf
    889 
    890 namespace RawInstrProf {
    891 
    892 // Version 1: First version
    893 // Version 2: Added value profile data section. Per-function control data
    894 // struct has more fields to describe value profile information.
    895 // Version 3: Compressed name section support. Function PGO name reference
    896 // from control data struct is changed from raw pointer to Name's MD5 value.
    897 // Version 4: ValueDataBegin and ValueDataSizes fields are removed from the
    898 // raw header.
    899 const uint64_t Version = INSTR_PROF_RAW_VERSION;
    900 
    901 template <class IntPtrT> inline uint64_t getMagic();
    902 template <> inline uint64_t getMagic<uint64_t>() {
    903   return INSTR_PROF_RAW_MAGIC_64;
    904 }
    905 
    906 template <> inline uint64_t getMagic<uint32_t>() {
    907   return INSTR_PROF_RAW_MAGIC_32;
    908 }
    909 
    910 // Per-function profile data header/control structure.
    911 // The definition should match the structure defined in
    912 // compiler-rt/lib/profile/InstrProfiling.h.
    913 // It should also match the synthesized type in
    914 // Transforms/Instrumentation/InstrProfiling.cpp:getOrCreateRegionCounters.
    915 template <class IntPtrT> struct LLVM_ALIGNAS(8) ProfileData {
    916   #define INSTR_PROF_DATA(Type, LLVMType, Name, Init) Type Name;
    917   #include "llvm/ProfileData/InstrProfData.inc"
    918 };
    919 
    920 // File header structure of the LLVM profile data in raw format.
    921 // The definition should match the header referenced in
    922 // compiler-rt/lib/profile/InstrProfilingFile.c  and
    923 // InstrProfilingBuffer.c.
    924 struct Header {
    925 #define INSTR_PROF_RAW_HEADER(Type, Name, Init) const Type Name;
    926 #include "llvm/ProfileData/InstrProfData.inc"
    927 };
    928 
    929 } // end namespace RawInstrProf
    930 
    931 } // end namespace llvm
    932 
    933 #endif // LLVM_PROFILEDATA_INSTRPROF_H
    934