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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/ArrayRef.h"
     20 #include "llvm/ADT/STLExtras.h"
     21 #include "llvm/ADT/StringRef.h"
     22 #include "llvm/ADT/StringSet.h"
     23 #include "llvm/ADT/Triple.h"
     24 #include "llvm/IR/GlobalValue.h"
     25 #include "llvm/IR/ProfileSummary.h"
     26 #include "llvm/ProfileData/InstrProfData.inc"
     27 #include "llvm/Support/Compiler.h"
     28 #include "llvm/Support/Endian.h"
     29 #include "llvm/Support/Error.h"
     30 #include "llvm/Support/ErrorHandling.h"
     31 #include "llvm/Support/Host.h"
     32 #include "llvm/Support/MD5.h"
     33 #include "llvm/Support/MathExtras.h"
     34 #include "llvm/Support/raw_ostream.h"
     35 #include <algorithm>
     36 #include <cassert>
     37 #include <cstddef>
     38 #include <cstdint>
     39 #include <cstring>
     40 #include <list>
     41 #include <memory>
     42 #include <string>
     43 #include <system_error>
     44 #include <utility>
     45 #include <vector>
     46 
     47 namespace llvm {
     48 
     49 class Function;
     50 class GlobalVariable;
     51 struct InstrProfRecord;
     52 class InstrProfSymtab;
     53 class Instruction;
     54 class MDNode;
     55 class Module;
     56 
     57 enum InstrProfSectKind {
     58 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) Kind,
     59 #include "llvm/ProfileData/InstrProfData.inc"
     60 };
     61 
     62 /// Return the name of the profile section corresponding to \p IPSK.
     63 ///
     64 /// The name of the section depends on the object format type \p OF. If
     65 /// \p AddSegmentInfo is true, a segment prefix and additional linker hints may
     66 /// be added to the section name (this is the default).
     67 std::string getInstrProfSectionName(InstrProfSectKind IPSK,
     68                                     Triple::ObjectFormatType OF,
     69                                     bool AddSegmentInfo = true);
     70 
     71 /// Return the name profile runtime entry point to do value profiling
     72 /// for a given site.
     73 inline StringRef getInstrProfValueProfFuncName() {
     74   return INSTR_PROF_VALUE_PROF_FUNC_STR;
     75 }
     76 
     77 /// Return the name profile runtime entry point to do value range profiling.
     78 inline StringRef getInstrProfValueRangeProfFuncName() {
     79   return INSTR_PROF_VALUE_RANGE_PROF_FUNC_STR;
     80 }
     81 
     82 /// Return the name prefix of variables containing instrumented function names.
     83 inline StringRef getInstrProfNameVarPrefix() { return "__profn_"; }
     84 
     85 /// Return the name prefix of variables containing per-function control data.
     86 inline StringRef getInstrProfDataVarPrefix() { return "__profd_"; }
     87 
     88 /// Return the name prefix of profile counter variables.
     89 inline StringRef getInstrProfCountersVarPrefix() { return "__profc_"; }
     90 
     91 /// Return the name prefix of value profile variables.
     92 inline StringRef getInstrProfValuesVarPrefix() { return "__profvp_"; }
     93 
     94 /// Return the name of value profile node array variables:
     95 inline StringRef getInstrProfVNodesVarName() { return "__llvm_prf_vnodes"; }
     96 
     97 /// Return the name prefix of the COMDAT group for instrumentation variables
     98 /// associated with a COMDAT function.
     99 inline StringRef getInstrProfComdatPrefix() { return "__profv_"; }
    100 
    101 /// Return the name of the variable holding the strings (possibly compressed)
    102 /// of all function's PGO names.
    103 inline StringRef getInstrProfNamesVarName() {
    104   return "__llvm_prf_nm";
    105 }
    106 
    107 /// Return the name of a covarage mapping variable (internal linkage)
    108 /// for each instrumented source module. Such variables are allocated
    109 /// in the __llvm_covmap section.
    110 inline StringRef getCoverageMappingVarName() {
    111   return "__llvm_coverage_mapping";
    112 }
    113 
    114 /// Return the name of the internal variable recording the array
    115 /// of PGO name vars referenced by the coverage mapping. The owning
    116 /// functions of those names are not emitted by FE (e.g, unused inline
    117 /// functions.)
    118 inline StringRef getCoverageUnusedNamesVarName() {
    119   return "__llvm_coverage_names";
    120 }
    121 
    122 /// Return the name of function that registers all the per-function control
    123 /// data at program startup time by calling __llvm_register_function. This
    124 /// function has internal linkage and is called by  __llvm_profile_init
    125 /// runtime method. This function is not generated for these platforms:
    126 /// Darwin, Linux, and FreeBSD.
    127 inline StringRef getInstrProfRegFuncsName() {
    128   return "__llvm_profile_register_functions";
    129 }
    130 
    131 /// Return the name of the runtime interface that registers per-function control
    132 /// data for one instrumented function.
    133 inline StringRef getInstrProfRegFuncName() {
    134   return "__llvm_profile_register_function";
    135 }
    136 
    137 /// Return the name of the runtime interface that registers the PGO name strings.
    138 inline StringRef getInstrProfNamesRegFuncName() {
    139   return "__llvm_profile_register_names_function";
    140 }
    141 
    142 /// Return the name of the runtime initialization method that is generated by
    143 /// the compiler. The function calls __llvm_profile_register_functions and
    144 /// __llvm_profile_override_default_filename functions if needed. This function
    145 /// has internal linkage and invoked at startup time via init_array.
    146 inline StringRef getInstrProfInitFuncName() { return "__llvm_profile_init"; }
    147 
    148 /// Return the name of the hook variable defined in profile runtime library.
    149 /// A reference to the variable causes the linker to link in the runtime
    150 /// initialization module (which defines the hook variable).
    151 inline StringRef getInstrProfRuntimeHookVarName() {
    152   return INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_RUNTIME_VAR);
    153 }
    154 
    155 /// Return the name of the compiler generated function that references the
    156 /// runtime hook variable. The function is a weak global.
    157 inline StringRef getInstrProfRuntimeHookVarUseFuncName() {
    158   return "__llvm_profile_runtime_user";
    159 }
    160 
    161 /// Return the marker used to separate PGO names during serialization.
    162 inline StringRef getInstrProfNameSeparator() { return "\01"; }
    163 
    164 /// Return the modified name for function \c F suitable to be
    165 /// used the key for profile lookup. Variable \c InLTO indicates if this
    166 /// is called in LTO optimization passes.
    167 std::string getPGOFuncName(const Function &F, bool InLTO = false,
    168                            uint64_t Version = INSTR_PROF_INDEX_VERSION);
    169 
    170 /// Return the modified name for a function suitable to be
    171 /// used the key for profile lookup. The function's original
    172 /// name is \c RawFuncName and has linkage of type \c Linkage.
    173 /// The function is defined in module \c FileName.
    174 std::string getPGOFuncName(StringRef RawFuncName,
    175                            GlobalValue::LinkageTypes Linkage,
    176                            StringRef FileName,
    177                            uint64_t Version = INSTR_PROF_INDEX_VERSION);
    178 
    179 /// Return the name of the global variable used to store a function
    180 /// name in PGO instrumentation. \c FuncName is the name of the function
    181 /// returned by the \c getPGOFuncName call.
    182 std::string getPGOFuncNameVarName(StringRef FuncName,
    183                                   GlobalValue::LinkageTypes Linkage);
    184 
    185 /// Create and return the global variable for function name used in PGO
    186 /// instrumentation. \c FuncName is the name of the function returned
    187 /// by \c getPGOFuncName call.
    188 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName);
    189 
    190 /// Create and return the global variable for function name used in PGO
    191 /// instrumentation.  /// \c FuncName is the name of the function
    192 /// returned by \c getPGOFuncName call, \c M is the owning module,
    193 /// and \c Linkage is the linkage of the instrumented function.
    194 GlobalVariable *createPGOFuncNameVar(Module &M,
    195                                      GlobalValue::LinkageTypes Linkage,
    196                                      StringRef PGOFuncName);
    197 
    198 /// Return the initializer in string of the PGO name var \c NameVar.
    199 StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar);
    200 
    201 /// Given a PGO function name, remove the filename prefix and return
    202 /// the original (static) function name.
    203 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName,
    204                                    StringRef FileName = "<unknown>");
    205 
    206 /// Given a vector of strings (function PGO names) \c NameStrs, the
    207 /// method generates a combined string \c Result thatis ready to be
    208 /// serialized.  The \c Result string is comprised of three fields:
    209 /// The first field is the legnth of the uncompressed strings, and the
    210 /// the second field is the length of the zlib-compressed string.
    211 /// Both fields are encoded in ULEB128.  If \c doCompress is false, the
    212 ///  third field is the uncompressed strings; otherwise it is the
    213 /// compressed string. When the string compression is off, the
    214 /// second field will have value zero.
    215 Error collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,
    216                                 bool doCompression, std::string &Result);
    217 
    218 /// Produce \c Result string with the same format described above. The input
    219 /// is vector of PGO function name variables that are referenced.
    220 Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
    221                                 std::string &Result, bool doCompression = true);
    222 
    223 /// \c NameStrings is a string composed of one of more sub-strings encoded in
    224 /// the format described above. The substrings are separated by 0 or more zero
    225 /// bytes. This method decodes the string and populates the \c Symtab.
    226 Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab);
    227 
    228 /// Check if INSTR_PROF_RAW_VERSION_VAR is defined. This global is only being
    229 /// set in IR PGO compilation.
    230 bool isIRPGOFlagSet(const Module *M);
    231 
    232 /// Check if we can safely rename this Comdat function. Instances of the same
    233 /// comdat function may have different control flows thus can not share the
    234 /// same counter variable.
    235 bool canRenameComdatFunc(const Function &F, bool CheckAddressTaken = false);
    236 
    237 enum InstrProfValueKind : uint32_t {
    238 #define VALUE_PROF_KIND(Enumerator, Value) Enumerator = Value,
    239 #include "llvm/ProfileData/InstrProfData.inc"
    240 };
    241 
    242 /// Get the value profile data for value site \p SiteIdx from \p InstrProfR
    243 /// and annotate the instruction \p Inst with the value profile meta data.
    244 /// Annotate up to \p MaxMDCount (default 3) number of records per value site.
    245 void annotateValueSite(Module &M, Instruction &Inst,
    246                        const InstrProfRecord &InstrProfR,
    247                        InstrProfValueKind ValueKind, uint32_t SiteIndx,
    248                        uint32_t MaxMDCount = 3);
    249 
    250 /// Same as the above interface but using an ArrayRef, as well as \p Sum.
    251 void annotateValueSite(Module &M, Instruction &Inst,
    252                        ArrayRef<InstrProfValueData> VDs, uint64_t Sum,
    253                        InstrProfValueKind ValueKind, uint32_t MaxMDCount);
    254 
    255 /// Extract the value profile data from \p Inst which is annotated with
    256 /// value profile meta data. Return false if there is no value data annotated,
    257 /// otherwise  return true.
    258 bool getValueProfDataFromInst(const Instruction &Inst,
    259                               InstrProfValueKind ValueKind,
    260                               uint32_t MaxNumValueData,
    261                               InstrProfValueData ValueData[],
    262                               uint32_t &ActualNumValueData, uint64_t &TotalC);
    263 
    264 inline StringRef getPGOFuncNameMetadataName() { return "PGOFuncName"; }
    265 
    266 /// Return the PGOFuncName meta data associated with a function.
    267 MDNode *getPGOFuncNameMetadata(const Function &F);
    268 
    269 /// Create the PGOFuncName meta data if PGOFuncName is different from
    270 /// function's raw name. This should only apply to internal linkage functions
    271 /// declared by users only.
    272 void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName);
    273 
    274 /// Check if we can use Comdat for profile variables. This will eliminate
    275 /// the duplicated profile variables for Comdat functions.
    276 bool needsComdatForCounter(const Function &F, const Module &M);
    277 
    278 const std::error_category &instrprof_category();
    279 
    280 enum class instrprof_error {
    281   success = 0,
    282   eof,
    283   unrecognized_format,
    284   bad_magic,
    285   bad_header,
    286   unsupported_version,
    287   unsupported_hash_type,
    288   too_large,
    289   truncated,
    290   malformed,
    291   unknown_function,
    292   hash_mismatch,
    293   count_mismatch,
    294   counter_overflow,
    295   value_site_count_mismatch,
    296   compress_failed,
    297   uncompress_failed,
    298   empty_raw_profile,
    299   zlib_unavailable
    300 };
    301 
    302 inline std::error_code make_error_code(instrprof_error E) {
    303   return std::error_code(static_cast<int>(E), instrprof_category());
    304 }
    305 
    306 class InstrProfError : public ErrorInfo<InstrProfError> {
    307 public:
    308   InstrProfError(instrprof_error Err) : Err(Err) {
    309     assert(Err != instrprof_error::success && "Not an error");
    310   }
    311 
    312   std::string message() const override;
    313 
    314   void log(raw_ostream &OS) const override { OS << message(); }
    315 
    316   std::error_code convertToErrorCode() const override {
    317     return make_error_code(Err);
    318   }
    319 
    320   instrprof_error get() const { return Err; }
    321 
    322   /// Consume an Error and return the raw enum value contained within it. The
    323   /// Error must either be a success value, or contain a single InstrProfError.
    324   static instrprof_error take(Error E) {
    325     auto Err = instrprof_error::success;
    326     handleAllErrors(std::move(E), [&Err](const InstrProfError &IPE) {
    327       assert(Err == instrprof_error::success && "Multiple errors encountered");
    328       Err = IPE.get();
    329     });
    330     return Err;
    331   }
    332 
    333   static char ID;
    334 
    335 private:
    336   instrprof_error Err;
    337 };
    338 
    339 class SoftInstrProfErrors {
    340   /// Count the number of soft instrprof_errors encountered and keep track of
    341   /// the first such error for reporting purposes.
    342 
    343   /// The first soft error encountered.
    344   instrprof_error FirstError = instrprof_error::success;
    345 
    346   /// The number of hash mismatches.
    347   unsigned NumHashMismatches = 0;
    348 
    349   /// The number of count mismatches.
    350   unsigned NumCountMismatches = 0;
    351 
    352   /// The number of counter overflows.
    353   unsigned NumCounterOverflows = 0;
    354 
    355   /// The number of value site count mismatches.
    356   unsigned NumValueSiteCountMismatches = 0;
    357 
    358 public:
    359   SoftInstrProfErrors() = default;
    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 
    396 class SectionRef;
    397 
    398 } // end namespace object
    399 
    400 namespace IndexedInstrProf {
    401 
    402 uint64_t ComputeHash(StringRef K);
    403 
    404 } // end namespace IndexedInstrProf
    405 
    406 /// A symbol table used for function PGO name look-up with keys
    407 /// (such as pointers, md5hash values) to the function. A function's
    408 /// PGO name or name's md5hash are used in retrieving the profile
    409 /// data of the function. See \c getPGOFuncName() method for details
    410 /// on how PGO name is formed.
    411 class InstrProfSymtab {
    412 public:
    413   using AddrHashMap = std::vector<std::pair<uint64_t, uint64_t>>;
    414 
    415 private:
    416   StringRef Data;
    417   uint64_t Address = 0;
    418   // Unique name strings.
    419   StringSet<> NameTab;
    420   // A map from MD5 keys to function name strings.
    421   std::vector<std::pair<uint64_t, StringRef>> MD5NameMap;
    422   // A map from MD5 keys to function define. We only populate this map
    423   // when build the Symtab from a Module.
    424   std::vector<std::pair<uint64_t, Function *>> MD5FuncMap;
    425   // A map from function runtime address to function name MD5 hash.
    426   // This map is only populated and used by raw instr profile reader.
    427   AddrHashMap AddrToMD5Map;
    428   bool Sorted = false;
    429 
    430   static StringRef getExternalSymbol() {
    431     return "** External Symbol **";
    432   }
    433 
    434   // If the symtab is created by a series of calls to \c addFuncName, \c
    435   // finalizeSymtab needs to be called before looking up function names.
    436   // This is required because the underlying map is a vector (for space
    437   // efficiency) which needs to be sorted.
    438   inline void finalizeSymtab();
    439 
    440 public:
    441   InstrProfSymtab() = default;
    442 
    443   /// Create InstrProfSymtab from an object file section which
    444   /// contains function PGO names. When section may contain raw
    445   /// string data or string data in compressed form. This method
    446   /// only initialize the symtab with reference to the data and
    447   /// the section base address. The decompression will be delayed
    448   /// until before it is used. See also \c create(StringRef) method.
    449   Error create(object::SectionRef &Section);
    450 
    451   /// This interface is used by reader of CoverageMapping test
    452   /// format.
    453   inline Error create(StringRef D, uint64_t BaseAddr);
    454 
    455   /// \c NameStrings is a string composed of one of more sub-strings
    456   ///  encoded in the format described in \c collectPGOFuncNameStrings.
    457   /// This method is a wrapper to \c readPGOFuncNameStrings method.
    458   inline Error create(StringRef NameStrings);
    459 
    460   /// A wrapper interface to populate the PGO symtab with functions
    461   /// decls from module \c M. This interface is used by transformation
    462   /// passes such as indirect function call promotion. Variable \c InLTO
    463   /// indicates if this is called from LTO optimization passes.
    464   Error create(Module &M, bool InLTO = false);
    465 
    466   /// Create InstrProfSymtab from a set of names iteratable from
    467   /// \p IterRange. This interface is used by IndexedProfReader.
    468   template <typename NameIterRange> Error create(const NameIterRange &IterRange);
    469 
    470   /// Update the symtab by adding \p FuncName to the table. This interface
    471   /// is used by the raw and text profile readers.
    472   Error addFuncName(StringRef FuncName) {
    473     if (FuncName.empty())
    474       return make_error<InstrProfError>(instrprof_error::malformed);
    475     auto Ins = NameTab.insert(FuncName);
    476     if (Ins.second) {
    477       MD5NameMap.push_back(std::make_pair(
    478           IndexedInstrProf::ComputeHash(FuncName), Ins.first->getKey()));
    479       Sorted = false;
    480     }
    481     return Error::success();
    482   }
    483 
    484   /// Map a function address to its name's MD5 hash. This interface
    485   /// is only used by the raw profiler reader.
    486   void mapAddress(uint64_t Addr, uint64_t MD5Val) {
    487     AddrToMD5Map.push_back(std::make_pair(Addr, MD5Val));
    488   }
    489 
    490   /// Return a function's hash, or 0, if the function isn't in this SymTab.
    491   uint64_t getFunctionHashFromAddress(uint64_t Address);
    492 
    493   /// Return function's PGO name from the function name's symbol
    494   /// address in the object file. If an error occurs, return
    495   /// an empty string.
    496   StringRef getFuncName(uint64_t FuncNameAddress, size_t NameSize);
    497 
    498   /// Return function's PGO name from the name's md5 hash value.
    499   /// If not found, return an empty string.
    500   inline StringRef getFuncName(uint64_t FuncMD5Hash);
    501 
    502   /// Just like getFuncName, except that it will return a non-empty StringRef
    503   /// if the function is external to this symbol table. All such cases
    504   /// will be represented using the same StringRef value.
    505   inline StringRef getFuncNameOrExternalSymbol(uint64_t FuncMD5Hash);
    506 
    507   /// True if Symbol is the value used to represent external symbols.
    508   static bool isExternalSymbol(const StringRef &Symbol) {
    509     return Symbol == InstrProfSymtab::getExternalSymbol();
    510   }
    511 
    512   /// Return function from the name's md5 hash. Return nullptr if not found.
    513   inline Function *getFunction(uint64_t FuncMD5Hash);
    514 
    515   /// Return the function's original assembly name by stripping off
    516   /// the prefix attached (to symbols with priviate linkage). For
    517   /// global functions, it returns the same string as getFuncName.
    518   inline StringRef getOrigFuncName(uint64_t FuncMD5Hash);
    519 
    520   /// Return the name section data.
    521   inline StringRef getNameData() const { return Data; }
    522 };
    523 
    524 Error InstrProfSymtab::create(StringRef D, uint64_t BaseAddr) {
    525   Data = D;
    526   Address = BaseAddr;
    527   return Error::success();
    528 }
    529 
    530 Error InstrProfSymtab::create(StringRef NameStrings) {
    531   return readPGOFuncNameStrings(NameStrings, *this);
    532 }
    533 
    534 template <typename NameIterRange>
    535 Error InstrProfSymtab::create(const NameIterRange &IterRange) {
    536   for (auto Name : IterRange)
    537     if (Error E = addFuncName(Name))
    538       return E;
    539 
    540   finalizeSymtab();
    541   return Error::success();
    542 }
    543 
    544 void InstrProfSymtab::finalizeSymtab() {
    545   if (Sorted)
    546     return;
    547   llvm::sort(MD5NameMap.begin(), MD5NameMap.end(), less_first());
    548   llvm::sort(MD5FuncMap.begin(), MD5FuncMap.end(), less_first());
    549   llvm::sort(AddrToMD5Map.begin(), AddrToMD5Map.end(), less_first());
    550   AddrToMD5Map.erase(std::unique(AddrToMD5Map.begin(), AddrToMD5Map.end()),
    551                      AddrToMD5Map.end());
    552   Sorted = true;
    553 }
    554 
    555 StringRef InstrProfSymtab::getFuncNameOrExternalSymbol(uint64_t FuncMD5Hash) {
    556   StringRef ret = getFuncName(FuncMD5Hash);
    557   if (ret.empty())
    558     return InstrProfSymtab::getExternalSymbol();
    559   return ret;
    560 }
    561 
    562 StringRef InstrProfSymtab::getFuncName(uint64_t FuncMD5Hash) {
    563   finalizeSymtab();
    564   auto Result =
    565       std::lower_bound(MD5NameMap.begin(), MD5NameMap.end(), FuncMD5Hash,
    566                        [](const std::pair<uint64_t, std::string> &LHS,
    567                           uint64_t RHS) { return LHS.first < RHS; });
    568   if (Result != MD5NameMap.end() && Result->first == FuncMD5Hash)
    569     return Result->second;
    570   return StringRef();
    571 }
    572 
    573 Function* InstrProfSymtab::getFunction(uint64_t FuncMD5Hash) {
    574   finalizeSymtab();
    575   auto Result =
    576       std::lower_bound(MD5FuncMap.begin(), MD5FuncMap.end(), FuncMD5Hash,
    577                        [](const std::pair<uint64_t, Function*> &LHS,
    578                           uint64_t RHS) { return LHS.first < RHS; });
    579   if (Result != MD5FuncMap.end() && Result->first == FuncMD5Hash)
    580     return Result->second;
    581   return nullptr;
    582 }
    583 
    584 // See also getPGOFuncName implementation. These two need to be
    585 // matched.
    586 StringRef InstrProfSymtab::getOrigFuncName(uint64_t FuncMD5Hash) {
    587   StringRef PGOName = getFuncName(FuncMD5Hash);
    588   size_t S = PGOName.find_first_of(':');
    589   if (S == StringRef::npos)
    590     return PGOName;
    591   return PGOName.drop_front(S + 1);
    592 }
    593 
    594 struct InstrProfValueSiteRecord {
    595   /// Value profiling data pairs at a given value site.
    596   std::list<InstrProfValueData> ValueData;
    597 
    598   InstrProfValueSiteRecord() { ValueData.clear(); }
    599   template <class InputIterator>
    600   InstrProfValueSiteRecord(InputIterator F, InputIterator L)
    601       : ValueData(F, L) {}
    602 
    603   /// Sort ValueData ascending by Value
    604   void sortByTargetValues() {
    605     ValueData.sort(
    606         [](const InstrProfValueData &left, const InstrProfValueData &right) {
    607           return left.Value < right.Value;
    608         });
    609   }
    610   /// Sort ValueData Descending by Count
    611   inline void sortByCount();
    612 
    613   /// Merge data from another InstrProfValueSiteRecord
    614   /// Optionally scale merged counts by \p Weight.
    615   void merge(InstrProfValueSiteRecord &Input, uint64_t Weight,
    616              function_ref<void(instrprof_error)> Warn);
    617   /// Scale up value profile data counts.
    618   void scale(uint64_t Weight, function_ref<void(instrprof_error)> Warn);
    619 };
    620 
    621 /// Profiling information for a single function.
    622 struct InstrProfRecord {
    623   std::vector<uint64_t> Counts;
    624 
    625   InstrProfRecord() = default;
    626   InstrProfRecord(std::vector<uint64_t> Counts) : Counts(std::move(Counts)) {}
    627   InstrProfRecord(InstrProfRecord &&) = default;
    628   InstrProfRecord(const InstrProfRecord &RHS)
    629       : Counts(RHS.Counts),
    630         ValueData(RHS.ValueData
    631                       ? llvm::make_unique<ValueProfData>(*RHS.ValueData)
    632                       : nullptr) {}
    633   InstrProfRecord &operator=(InstrProfRecord &&) = default;
    634   InstrProfRecord &operator=(const InstrProfRecord &RHS) {
    635     Counts = RHS.Counts;
    636     if (!RHS.ValueData) {
    637       ValueData = nullptr;
    638       return *this;
    639     }
    640     if (!ValueData)
    641       ValueData = llvm::make_unique<ValueProfData>(*RHS.ValueData);
    642     else
    643       *ValueData = *RHS.ValueData;
    644     return *this;
    645   }
    646 
    647   /// Return the number of value profile kinds with non-zero number
    648   /// of profile sites.
    649   inline uint32_t getNumValueKinds() const;
    650   /// Return the number of instrumented sites for ValueKind.
    651   inline uint32_t getNumValueSites(uint32_t ValueKind) const;
    652 
    653   /// Return the total number of ValueData for ValueKind.
    654   inline uint32_t getNumValueData(uint32_t ValueKind) const;
    655 
    656   /// Return the number of value data collected for ValueKind at profiling
    657   /// site: Site.
    658   inline uint32_t getNumValueDataForSite(uint32_t ValueKind,
    659                                          uint32_t Site) const;
    660 
    661   /// Return the array of profiled values at \p Site. If \p TotalC
    662   /// is not null, the total count of all target values at this site
    663   /// will be stored in \c *TotalC.
    664   inline std::unique_ptr<InstrProfValueData[]>
    665   getValueForSite(uint32_t ValueKind, uint32_t Site,
    666                   uint64_t *TotalC = nullptr) const;
    667 
    668   /// Get the target value/counts of kind \p ValueKind collected at site
    669   /// \p Site and store the result in array \p Dest. Return the total
    670   /// counts of all target values at this site.
    671   inline uint64_t getValueForSite(InstrProfValueData Dest[], uint32_t ValueKind,
    672                                   uint32_t Site) const;
    673 
    674   /// Reserve space for NumValueSites sites.
    675   inline void reserveSites(uint32_t ValueKind, uint32_t NumValueSites);
    676 
    677   /// Add ValueData for ValueKind at value Site.
    678   void addValueData(uint32_t ValueKind, uint32_t Site,
    679                     InstrProfValueData *VData, uint32_t N,
    680                     InstrProfSymtab *SymTab);
    681 
    682   /// Merge the counts in \p Other into this one.
    683   /// Optionally scale merged counts by \p Weight.
    684   void merge(InstrProfRecord &Other, uint64_t Weight,
    685              function_ref<void(instrprof_error)> Warn);
    686 
    687   /// Scale up profile counts (including value profile data) by
    688   /// \p Weight.
    689   void scale(uint64_t Weight, function_ref<void(instrprof_error)> Warn);
    690 
    691   /// Sort value profile data (per site) by count.
    692   void sortValueData() {
    693     for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
    694       for (auto &SR : getValueSitesForKind(Kind))
    695         SR.sortByCount();
    696   }
    697 
    698   /// Clear value data entries and edge counters.
    699   void Clear() {
    700     Counts.clear();
    701     clearValueData();
    702   }
    703 
    704   /// Clear value data entries
    705   void clearValueData() { ValueData = nullptr; }
    706 
    707 private:
    708   struct ValueProfData {
    709     std::vector<InstrProfValueSiteRecord> IndirectCallSites;
    710     std::vector<InstrProfValueSiteRecord> MemOPSizes;
    711   };
    712   std::unique_ptr<ValueProfData> ValueData;
    713 
    714   MutableArrayRef<InstrProfValueSiteRecord>
    715   getValueSitesForKind(uint32_t ValueKind) {
    716     // Cast to /add/ const (should be an implicit_cast, ideally, if that's ever
    717     // implemented in LLVM) to call the const overload of this function, then
    718     // cast away the constness from the result.
    719     auto AR = const_cast<const InstrProfRecord *>(this)->getValueSitesForKind(
    720         ValueKind);
    721     return makeMutableArrayRef(
    722         const_cast<InstrProfValueSiteRecord *>(AR.data()), AR.size());
    723   }
    724   ArrayRef<InstrProfValueSiteRecord>
    725   getValueSitesForKind(uint32_t ValueKind) const {
    726     if (!ValueData)
    727       return None;
    728     switch (ValueKind) {
    729     case IPVK_IndirectCallTarget:
    730       return ValueData->IndirectCallSites;
    731     case IPVK_MemOPSize:
    732       return ValueData->MemOPSizes;
    733     default:
    734       llvm_unreachable("Unknown value kind!");
    735     }
    736   }
    737 
    738   std::vector<InstrProfValueSiteRecord> &
    739   getOrCreateValueSitesForKind(uint32_t ValueKind) {
    740     if (!ValueData)
    741       ValueData = llvm::make_unique<ValueProfData>();
    742     switch (ValueKind) {
    743     case IPVK_IndirectCallTarget:
    744       return ValueData->IndirectCallSites;
    745     case IPVK_MemOPSize:
    746       return ValueData->MemOPSizes;
    747     default:
    748       llvm_unreachable("Unknown value kind!");
    749     }
    750   }
    751 
    752   // Map indirect call target name hash to name string.
    753   uint64_t remapValue(uint64_t Value, uint32_t ValueKind,
    754                       InstrProfSymtab *SymTab);
    755 
    756   // Merge Value Profile data from Src record to this record for ValueKind.
    757   // Scale merged value counts by \p Weight.
    758   void mergeValueProfData(uint32_t ValkeKind, InstrProfRecord &Src,
    759                           uint64_t Weight,
    760                           function_ref<void(instrprof_error)> Warn);
    761 
    762   // Scale up value profile data count.
    763   void scaleValueProfData(uint32_t ValueKind, uint64_t Weight,
    764                           function_ref<void(instrprof_error)> Warn);
    765 };
    766 
    767 struct NamedInstrProfRecord : InstrProfRecord {
    768   StringRef Name;
    769   uint64_t Hash;
    770 
    771   NamedInstrProfRecord() = default;
    772   NamedInstrProfRecord(StringRef Name, uint64_t Hash,
    773                        std::vector<uint64_t> Counts)
    774       : InstrProfRecord(std::move(Counts)), Name(Name), Hash(Hash) {}
    775 };
    776 
    777 uint32_t InstrProfRecord::getNumValueKinds() const {
    778   uint32_t NumValueKinds = 0;
    779   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
    780     NumValueKinds += !(getValueSitesForKind(Kind).empty());
    781   return NumValueKinds;
    782 }
    783 
    784 uint32_t InstrProfRecord::getNumValueData(uint32_t ValueKind) const {
    785   uint32_t N = 0;
    786   for (auto &SR : getValueSitesForKind(ValueKind))
    787     N += SR.ValueData.size();
    788   return N;
    789 }
    790 
    791 uint32_t InstrProfRecord::getNumValueSites(uint32_t ValueKind) const {
    792   return getValueSitesForKind(ValueKind).size();
    793 }
    794 
    795 uint32_t InstrProfRecord::getNumValueDataForSite(uint32_t ValueKind,
    796                                                  uint32_t Site) const {
    797   return getValueSitesForKind(ValueKind)[Site].ValueData.size();
    798 }
    799 
    800 std::unique_ptr<InstrProfValueData[]>
    801 InstrProfRecord::getValueForSite(uint32_t ValueKind, uint32_t Site,
    802                                  uint64_t *TotalC) const {
    803   uint64_t Dummy;
    804   uint64_t &TotalCount = (TotalC == nullptr ? Dummy : *TotalC);
    805   uint32_t N = getNumValueDataForSite(ValueKind, Site);
    806   if (N == 0) {
    807     TotalCount = 0;
    808     return std::unique_ptr<InstrProfValueData[]>(nullptr);
    809   }
    810 
    811   auto VD = llvm::make_unique<InstrProfValueData[]>(N);
    812   TotalCount = getValueForSite(VD.get(), ValueKind, Site);
    813 
    814   return VD;
    815 }
    816 
    817 uint64_t InstrProfRecord::getValueForSite(InstrProfValueData Dest[],
    818                                           uint32_t ValueKind,
    819                                           uint32_t Site) const {
    820   uint32_t I = 0;
    821   uint64_t TotalCount = 0;
    822   for (auto V : getValueSitesForKind(ValueKind)[Site].ValueData) {
    823     Dest[I].Value = V.Value;
    824     Dest[I].Count = V.Count;
    825     TotalCount = SaturatingAdd(TotalCount, V.Count);
    826     I++;
    827   }
    828   return TotalCount;
    829 }
    830 
    831 void InstrProfRecord::reserveSites(uint32_t ValueKind, uint32_t NumValueSites) {
    832   if (!NumValueSites)
    833     return;
    834   getOrCreateValueSitesForKind(ValueKind).reserve(NumValueSites);
    835 }
    836 
    837 inline support::endianness getHostEndianness() {
    838   return sys::IsLittleEndianHost ? support::little : support::big;
    839 }
    840 
    841 // Include definitions for value profile data
    842 #define INSTR_PROF_VALUE_PROF_DATA
    843 #include "llvm/ProfileData/InstrProfData.inc"
    844 
    845 void InstrProfValueSiteRecord::sortByCount() {
    846   ValueData.sort(
    847       [](const InstrProfValueData &left, const InstrProfValueData &right) {
    848         return left.Count > right.Count;
    849       });
    850   // Now truncate
    851   size_t max_s = INSTR_PROF_MAX_NUM_VAL_PER_SITE;
    852   if (ValueData.size() > max_s)
    853     ValueData.resize(max_s);
    854 }
    855 
    856 namespace IndexedInstrProf {
    857 
    858 enum class HashT : uint32_t {
    859   MD5,
    860   Last = MD5
    861 };
    862 
    863 inline uint64_t ComputeHash(HashT Type, StringRef K) {
    864   switch (Type) {
    865   case HashT::MD5:
    866     return MD5Hash(K);
    867   }
    868   llvm_unreachable("Unhandled hash type");
    869 }
    870 
    871 const uint64_t Magic = 0x8169666f72706cff; // "\xfflprofi\x81"
    872 
    873 enum ProfVersion {
    874   // Version 1 is the first version. In this version, the value of
    875   // a key/value pair can only include profile data of a single function.
    876   // Due to this restriction, the number of block counters for a given
    877   // function is not recorded but derived from the length of the value.
    878   Version1 = 1,
    879   // The version 2 format supports recording profile data of multiple
    880   // functions which share the same key in one value field. To support this,
    881   // the number block counters is recorded as an uint64_t field right after the
    882   // function structural hash.
    883   Version2 = 2,
    884   // Version 3 supports value profile data. The value profile data is expected
    885   // to follow the block counter profile data.
    886   Version3 = 3,
    887   // In this version, profile summary data \c IndexedInstrProf::Summary is
    888   // stored after the profile header.
    889   Version4 = 4,
    890   // In this version, the frontend PGO stable hash algorithm defaults to V2.
    891   Version5 = 5,
    892   // The current version is 5.
    893   CurrentVersion = INSTR_PROF_INDEX_VERSION
    894 };
    895 const uint64_t Version = ProfVersion::CurrentVersion;
    896 
    897 const HashT HashType = HashT::MD5;
    898 
    899 inline uint64_t ComputeHash(StringRef K) { return ComputeHash(HashType, K); }
    900 
    901 // This structure defines the file header of the LLVM profile
    902 // data file in indexed-format.
    903 struct Header {
    904   uint64_t Magic;
    905   uint64_t Version;
    906   uint64_t Unused; // Becomes unused since version 4
    907   uint64_t HashType;
    908   uint64_t HashOffset;
    909 };
    910 
    911 // Profile summary data recorded in the profile data file in indexed
    912 // format. It is introduced in version 4. The summary data follows
    913 // right after the profile file header.
    914 struct Summary {
    915   struct Entry {
    916     uint64_t Cutoff; ///< The required percentile of total execution count.
    917     uint64_t
    918         MinBlockCount;  ///< The minimum execution count for this percentile.
    919     uint64_t NumBlocks; ///< Number of blocks >= the minumum execution count.
    920   };
    921   // The field kind enumerator to assigned value mapping should remain
    922   // unchanged  when a new kind is added or an old kind gets deleted in
    923   // the future.
    924   enum SummaryFieldKind {
    925     /// The total number of functions instrumented.
    926     TotalNumFunctions = 0,
    927     /// Total number of instrumented blocks/edges.
    928     TotalNumBlocks = 1,
    929     /// The maximal execution count among all functions.
    930     /// This field does not exist for profile data from IR based
    931     /// instrumentation.
    932     MaxFunctionCount = 2,
    933     /// Max block count of the program.
    934     MaxBlockCount = 3,
    935     /// Max internal block count of the program (excluding entry blocks).
    936     MaxInternalBlockCount = 4,
    937     /// The sum of all instrumented block counts.
    938     TotalBlockCount = 5,
    939     NumKinds = TotalBlockCount + 1
    940   };
    941 
    942   // The number of summmary fields following the summary header.
    943   uint64_t NumSummaryFields;
    944   // The number of Cutoff Entries (Summary::Entry) following summary fields.
    945   uint64_t NumCutoffEntries;
    946 
    947   Summary() = delete;
    948   Summary(uint32_t Size) { memset(this, 0, Size); }
    949 
    950   void operator delete(void *ptr) { ::operator delete(ptr); }
    951 
    952   static uint32_t getSize(uint32_t NumSumFields, uint32_t NumCutoffEntries) {
    953     return sizeof(Summary) + NumCutoffEntries * sizeof(Entry) +
    954            NumSumFields * sizeof(uint64_t);
    955   }
    956 
    957   const uint64_t *getSummaryDataBase() const {
    958     return reinterpret_cast<const uint64_t *>(this + 1);
    959   }
    960 
    961   uint64_t *getSummaryDataBase() {
    962     return reinterpret_cast<uint64_t *>(this + 1);
    963   }
    964 
    965   const Entry *getCutoffEntryBase() const {
    966     return reinterpret_cast<const Entry *>(
    967         &getSummaryDataBase()[NumSummaryFields]);
    968   }
    969 
    970   Entry *getCutoffEntryBase() {
    971     return reinterpret_cast<Entry *>(&getSummaryDataBase()[NumSummaryFields]);
    972   }
    973 
    974   uint64_t get(SummaryFieldKind K) const {
    975     return getSummaryDataBase()[K];
    976   }
    977 
    978   void set(SummaryFieldKind K, uint64_t V) {
    979     getSummaryDataBase()[K] = V;
    980   }
    981 
    982   const Entry &getEntry(uint32_t I) const { return getCutoffEntryBase()[I]; }
    983 
    984   void setEntry(uint32_t I, const ProfileSummaryEntry &E) {
    985     Entry &ER = getCutoffEntryBase()[I];
    986     ER.Cutoff = E.Cutoff;
    987     ER.MinBlockCount = E.MinCount;
    988     ER.NumBlocks = E.NumCounts;
    989   }
    990 };
    991 
    992 inline std::unique_ptr<Summary> allocSummary(uint32_t TotalSize) {
    993   return std::unique_ptr<Summary>(new (::operator new(TotalSize))
    994                                       Summary(TotalSize));
    995 }
    996 
    997 } // end namespace IndexedInstrProf
    998 
    999 namespace RawInstrProf {
   1000 
   1001 // Version 1: First version
   1002 // Version 2: Added value profile data section. Per-function control data
   1003 // struct has more fields to describe value profile information.
   1004 // Version 3: Compressed name section support. Function PGO name reference
   1005 // from control data struct is changed from raw pointer to Name's MD5 value.
   1006 // Version 4: ValueDataBegin and ValueDataSizes fields are removed from the
   1007 // raw header.
   1008 const uint64_t Version = INSTR_PROF_RAW_VERSION;
   1009 
   1010 template <class IntPtrT> inline uint64_t getMagic();
   1011 template <> inline uint64_t getMagic<uint64_t>() {
   1012   return INSTR_PROF_RAW_MAGIC_64;
   1013 }
   1014 
   1015 template <> inline uint64_t getMagic<uint32_t>() {
   1016   return INSTR_PROF_RAW_MAGIC_32;
   1017 }
   1018 
   1019 // Per-function profile data header/control structure.
   1020 // The definition should match the structure defined in
   1021 // compiler-rt/lib/profile/InstrProfiling.h.
   1022 // It should also match the synthesized type in
   1023 // Transforms/Instrumentation/InstrProfiling.cpp:getOrCreateRegionCounters.
   1024 template <class IntPtrT> struct alignas(8) ProfileData {
   1025   #define INSTR_PROF_DATA(Type, LLVMType, Name, Init) Type Name;
   1026   #include "llvm/ProfileData/InstrProfData.inc"
   1027 };
   1028 
   1029 // File header structure of the LLVM profile data in raw format.
   1030 // The definition should match the header referenced in
   1031 // compiler-rt/lib/profile/InstrProfilingFile.c  and
   1032 // InstrProfilingBuffer.c.
   1033 struct Header {
   1034 #define INSTR_PROF_RAW_HEADER(Type, Name, Init) const Type Name;
   1035 #include "llvm/ProfileData/InstrProfData.inc"
   1036 };
   1037 
   1038 } // end namespace RawInstrProf
   1039 
   1040 // Parse MemOP Size range option.
   1041 void getMemOPSizeRangeFromOption(StringRef Str, int64_t &RangeStart,
   1042                                  int64_t &RangeLast);
   1043 
   1044 } // end namespace llvm
   1045 
   1046 #endif // LLVM_PROFILEDATA_INSTRPROF_H
   1047