llvm/lib/ProfileData/InstrProf.cpp

   1 //===- InstrProf.cpp - Instrumented profiling format support --------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains support for clang's instrumentation based PGO and
  10 // coverage.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ProfileData/InstrProf.h"
  15 #include "llvm/ADT/ArrayRef.h"
  16 #include "llvm/ADT/SmallString.h"
  17 #include "llvm/ADT/SmallVector.h"
  18 #include "llvm/ADT/StringExtras.h"
  19 #include "llvm/ADT/StringRef.h"
  20 #include "llvm/ADT/Triple.h"
  21 #include "llvm/Config/config.h"
  22 #include "llvm/IR/Constant.h"
  23 #include "llvm/IR/Constants.h"
  24 #include "llvm/IR/Function.h"
  25 #include "llvm/IR/GlobalValue.h"
  26 #include "llvm/IR/GlobalVariable.h"
  27 #include "llvm/IR/Instruction.h"
  28 #include "llvm/IR/LLVMContext.h"
  29 #include "llvm/IR/MDBuilder.h"
  30 #include "llvm/IR/Metadata.h"
  31 #include "llvm/IR/Module.h"
  32 #include "llvm/IR/Type.h"
  33 #include "llvm/ProfileData/InstrProfReader.h"
  34 #include "llvm/Support/Casting.h"
  35 #include "llvm/Support/CommandLine.h"
  36 #include "llvm/Support/Compiler.h"
  37 #include "llvm/Support/Compression.h"
  38 #include "llvm/Support/Endian.h"
  39 #include "llvm/Support/Error.h"
  40 #include "llvm/Support/ErrorHandling.h"
  41 #include "llvm/Support/LEB128.h"
  42 #include "llvm/Support/ManagedStatic.h"
  43 #include "llvm/Support/MathExtras.h"
  44 #include "llvm/Support/Path.h"
  45 #include "llvm/Support/SwapByteOrder.h"
  46 #include <algorithm>
  47 #include <cassert>
  48 #include <cstddef>
  49 #include <cstdint>
  50 #include <cstring>
  51 #include <memory>
  52 #include <string>
  53 #include <system_error>
  54 #include <utility>
  55 #include <vector>
  56
  57 using namespace llvm;
  58
  59 static cl::opt<bool> StaticFuncFullModulePrefix(
  60     "static-func-full-module-prefix", cl::init(true), cl::Hidden,
  61     cl::desc("Use full module build paths in the profile counter names for "
  62              "static functions."));
  63
  64 // This option is tailored to users that have different top-level directory in
  65 // profile-gen and profile-use compilation. Users need to specific the number
  66 // of levels to strip. A value larger than the number of directories in the
  67 // source file will strip all the directory names and only leave the basename.
  68 //
  69 // Note current ThinLTO module importing for the indirect-calls assumes
  70 // the source directory name not being stripped. A non-zero option value here
  71 // can potentially prevent some inter-module indirect-call-promotions.
  72 static cl::opt<unsigned> StaticFuncStripDirNamePrefix(
  73     "static-func-strip-dirname-prefix", cl::init(0), cl::Hidden,
  74     cl::desc("Strip specified level of directory name from source path in "
  75              "the profile counter name for static functions."));
  76
  77 static std::string getInstrProfErrString(instrprof_error Err,
  78                                          const std::string &ErrMsg = "") {
  79   std::string Msg;
  80   raw_string_ostream OS(Msg);
  81
  82   switch (Err) {
  83   case instrprof_error::success:
  84     OS << "success";
  85     break;
  86   case instrprof_error::eof:
  87     OS << "end of File";
  88     break;
  89   case instrprof_error::unrecognized_format:
  90     OS << "unrecognized instrumentation profile encoding format";
  91     break;
  92   case instrprof_error::bad_magic:
  93     OS << "invalid instrumentation profile data (bad magic)";
  94     break;
  95   case instrprof_error::bad_header:
  96     OS << "invalid instrumentation profile data (file header is corrupt)";
  97     break;
  98   case instrprof_error::unsupported_version:
  99     OS << "unsupported instrumentation profile format version";
 100     break;
 101   case instrprof_error::unsupported_hash_type:
 102     OS << "unsupported instrumentation profile hash type";
 103     break;
 104   case instrprof_error::too_large:
 105     OS << "too much profile data";
 106     break;
 107   case instrprof_error::truncated:
 108     OS << "truncated profile data";
 109     break;
 110   case instrprof_error::malformed:
 111     OS << "malformed instrumentation profile data";
 112     break;
 113   case instrprof_error::missing_debug_info_for_correlation:
 114     OS << "debug info for correlation is required";
 115     break;
 116   case instrprof_error::unexpected_debug_info_for_correlation:
 117     OS << "debug info for correlation is not necessary";
 118     break;
 119   case instrprof_error::unable_to_correlate_profile:
 120     OS << "unable to correlate profile";
 121     break;
 122   case instrprof_error::unsupported_debug_format:
 123     OS << "unsupported debug info format (only DWARF is supported)";
 124     break;
 125   case instrprof_error::invalid_prof:
 126     OS << "invalid profile created. Please file a bug "
 127           "at: " BUG_REPORT_URL
 128           " and include the profraw files that caused this error.";
 129     break;
 130   case instrprof_error::unknown_function:
 131     OS << "no profile data available for function";
 132     break;
 133   case instrprof_error::hash_mismatch:
 134     OS << "function control flow change detected (hash mismatch)";
 135     break;
 136   case instrprof_error::count_mismatch:
 137     OS << "function basic block count change detected (counter mismatch)";
 138     break;
 139   case instrprof_error::counter_overflow:
 140     OS << "counter overflow";
 141     break;
 142   case instrprof_error::value_site_count_mismatch:
 143     OS << "function value site count change detected (counter mismatch)";
 144     break;
 145   case instrprof_error::compress_failed:
 146     OS << "failed to compress data (zlib)";
 147     break;
 148   case instrprof_error::uncompress_failed:
 149     OS << "failed to uncompress data (zlib)";
 150     break;
 151   case instrprof_error::empty_raw_profile:
 152     OS << "empty raw profile file";
 153     break;
 154   case instrprof_error::zlib_unavailable:
 155     OS << "profile uses zlib compression but the profile reader was built "
 156           "without zlib support";
 157     break;
 158   }
 159
 160   // If optional error message is not empty, append it to the message.
 161   if (!ErrMsg.empty())
 162     OS << ": " << ErrMsg;
 163
 164   return OS.str();
 165 }
 166
 167 namespace {
 168
 169 // FIXME: This class is only here to support the transition to llvm::Error. It
 170 // will be removed once this transition is complete. Clients should prefer to
 171 // deal with the Error value directly, rather than converting to error_code.
 172 class InstrProfErrorCategoryType : public std::error_category {
 173   const char *name() const noexcept override { return "llvm.instrprof"; }
 174
 175   std::string message(int IE) const override {
 176     return getInstrProfErrString(static_cast<instrprof_error>(IE));
 177   }
 178 };
 179
 180 } // end anonymous namespace
 181
 182 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
 183
 184 const std::error_category &llvm::instrprof_category() {
 185   return *ErrorCategory;
 186 }
 187
 188 namespace {
 189
 190 const char *InstrProfSectNameCommon[] = {
 191 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix)      \
 192   SectNameCommon,
 193 #include "llvm/ProfileData/InstrProfData.inc"
 194 };
 195
 196 const char *InstrProfSectNameCoff[] = {
 197 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix)      \
 198   SectNameCoff,
 199 #include "llvm/ProfileData/InstrProfData.inc"
 200 };
 201
 202 const char *InstrProfSectNamePrefix[] = {
 203 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix)      \
 204   Prefix,
 205 #include "llvm/ProfileData/InstrProfData.inc"
 206 };
 207
 208 } // namespace
 209
 210 namespace llvm {
 211
 212 cl::opt<bool> DoInstrProfNameCompression(
 213     "enable-name-compression",
 214     cl::desc("Enable name/filename string compression"), cl::init(true));
 215
 216 std::string getInstrProfSectionName(InstrProfSectKind IPSK,
 217                                     Triple::ObjectFormatType OF,
 218                                     bool AddSegmentInfo) {
 219   std::string SectName;
 220
 221   if (OF == Triple::MachO && AddSegmentInfo)
 222     SectName = InstrProfSectNamePrefix[IPSK];
 223
 224   if (OF == Triple::COFF)
 225     SectName += InstrProfSectNameCoff[IPSK];
 226   else
 227     SectName += InstrProfSectNameCommon[IPSK];
 228
 229   if (OF == Triple::MachO && IPSK == IPSK_data && AddSegmentInfo)
 230     SectName += ",regular,live_support";
 231
 232   return SectName;
 233 }
 234
 235 void SoftInstrProfErrors::addError(instrprof_error IE) {
 236   if (IE == instrprof_error::success)
 237     return;
 238
 239   if (FirstError == instrprof_error::success)
 240     FirstError = IE;
 241
 242   switch (IE) {
 243   case instrprof_error::hash_mismatch:
 244     ++NumHashMismatches;
 245     break;
 246   case instrprof_error::count_mismatch:
 247     ++NumCountMismatches;
 248     break;
 249   case instrprof_error::counter_overflow:
 250     ++NumCounterOverflows;
 251     break;
 252   case instrprof_error::value_site_count_mismatch:
 253     ++NumValueSiteCountMismatches;
 254     break;
 255   default:
 256     llvm_unreachable("Not a soft error");
 257   }
 258 }
 259
 260 std::string InstrProfError::message() const {
 261   return getInstrProfErrString(Err, Msg);
 262 }
 263
 264 char InstrProfError::ID = 0;
 265
 266 std::string getPGOFuncName(StringRef RawFuncName,
 267                            GlobalValue::LinkageTypes Linkage,
 268                            StringRef FileName,
 269                            uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
 270   return GlobalValue::getGlobalIdentifier(RawFuncName, Linkage, FileName);
 271 }
 272
 273 // Strip NumPrefix level of directory name from PathNameStr. If the number of
 274 // directory separators is less than NumPrefix, strip all the directories and
 275 // leave base file name only.
 276 static StringRef stripDirPrefix(StringRef PathNameStr, uint32_t NumPrefix) {
 277   uint32_t Count = NumPrefix;
 278   uint32_t Pos = 0, LastPos = 0;
 279   for (auto & CI : PathNameStr) {
 280     ++Pos;
 281     if (llvm::sys::path::is_separator(CI)) {
 282       LastPos = Pos;
 283       --Count;
 284     }
 285     if (Count == 0)
 286       break;
 287   }
 288   return PathNameStr.substr(LastPos);
 289 }
 290
 291 // Return the PGOFuncName. This function has some special handling when called
 292 // in LTO optimization. The following only applies when calling in LTO passes
 293 // (when \c InLTO is true): LTO's internalization privatizes many global linkage
 294 // symbols. This happens after value profile annotation, but those internal
 295 // linkage functions should not have a source prefix.
 296 // Additionally, for ThinLTO mode, exported internal functions are promoted
 297 // and renamed. We need to ensure that the original internal PGO name is
 298 // used when computing the GUID that is compared against the profiled GUIDs.
 299 // To differentiate compiler generated internal symbols from original ones,
 300 // PGOFuncName meta data are created and attached to the original internal
 301 // symbols in the value profile annotation step
 302 // (PGOUseFunc::annotateIndirectCallSites). If a symbol does not have the meta
 303 // data, its original linkage must be non-internal.
 304 std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
 305   if (!InLTO) {
 306     StringRef FileName(F.getParent()->getSourceFileName());
 307     uint32_t StripLevel = StaticFuncFullModulePrefix ? 0 : (uint32_t)-1;
 308     if (StripLevel < StaticFuncStripDirNamePrefix)
 309       StripLevel = StaticFuncStripDirNamePrefix;
 310     if (StripLevel)
 311       FileName = stripDirPrefix(FileName, StripLevel);
 312     return getPGOFuncName(F.getName(), F.getLinkage(), FileName, Version);
 313   }
 314
 315   // In LTO mode (when InLTO is true), first check if there is a meta data.
 316   if (MDNode *MD = getPGOFuncNameMetadata(F)) {
 317     StringRef S = cast<MDString>(MD->getOperand(0))->getString();
 318     return S.str();
 319   }
 320
 321   // If there is no meta data, the function must be a global before the value
 322   // profile annotation pass. Its current linkage may be internal if it is
 323   // internalized in LTO mode.
 324   return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
 325 }
 326
 327 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
 328   if (FileName.empty())
 329     return PGOFuncName;
 330   // Drop the file name including ':'. See also getPGOFuncName.
 331   if (PGOFuncName.startswith(FileName))
 332     PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
 333   return PGOFuncName;
 334 }
 335
 336 // \p FuncName is the string used as profile lookup key for the function. A
 337 // symbol is created to hold the name. Return the legalized symbol name.
 338 std::string getPGOFuncNameVarName(StringRef FuncName,
 339                                   GlobalValue::LinkageTypes Linkage) {
 340   std::string VarName = std::string(getInstrProfNameVarPrefix());
 341   VarName += FuncName;
 342
 343   if (!GlobalValue::isLocalLinkage(Linkage))
 344     return VarName;
 345
 346   // Now fix up illegal chars in local VarName that may upset the assembler.
 347   const char *InvalidChars = "-:<>/\"'";
 348   size_t found = VarName.find_first_of(InvalidChars);
 349   while (found != std::string::npos) {
 350     VarName[found] = '_';
 351     found = VarName.find_first_of(InvalidChars, found + 1);
 352   }
 353   return VarName;
 354 }
 355
 356 GlobalVariable *createPGOFuncNameVar(Module &M,
 357                                      GlobalValue::LinkageTypes Linkage,
 358                                      StringRef PGOFuncName) {
 359   // We generally want to match the function's linkage, but available_externally
 360   // and extern_weak both have the wrong semantics, and anything that doesn't
 361   // need to link across compilation units doesn't need to be visible at all.
 362   if (Linkage == GlobalValue::ExternalWeakLinkage)
 363     Linkage = GlobalValue::LinkOnceAnyLinkage;
 364   else if (Linkage == GlobalValue::AvailableExternallyLinkage)
 365     Linkage = GlobalValue::LinkOnceODRLinkage;
 366   else if (Linkage == GlobalValue::InternalLinkage ||
 367            Linkage == GlobalValue::ExternalLinkage)
 368     Linkage = GlobalValue::PrivateLinkage;
 369
 370   auto *Value =
 371       ConstantDataArray::getString(M.getContext(), PGOFuncName, false);
 372   auto FuncNameVar =
 373       new GlobalVariable(M, Value->getType(), true, Linkage, Value,
 374                          getPGOFuncNameVarName(PGOFuncName, Linkage));
 375
 376   // Hide the symbol so that we correctly get a copy for each executable.
 377   if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
 378     FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
 379
 380   return FuncNameVar;
 381 }
 382
 383 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName) {
 384   return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), PGOFuncName);
 385 }
 386
 387 Error InstrProfSymtab::create(Module &M, bool InLTO) {
 388   for (Function &F : M) {
 389     // Function may not have a name: like using asm("") to overwrite the name.
 390     // Ignore in this case.
 391     if (!F.hasName())
 392       continue;
 393     const std::string &PGOFuncName = getPGOFuncName(F, InLTO);
 394     if (Error E = addFuncName(PGOFuncName))
 395       return E;
 396     MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
 397     // In ThinLTO, local function may have been promoted to global and have
 398     // suffix ".llvm." added to the function name. We need to add the
 399     // stripped function name to the symbol table so that we can find a match
 400     // from profile.
 401     //
 402     // We may have other suffixes similar as ".llvm." which are needed to
 403     // be stripped before the matching, but ".__uniq." suffix which is used
 404     // to differentiate internal linkage functions in different modules
 405     // should be kept. Now this is the only suffix with the pattern ".xxx"
 406     // which is kept before matching.
 407     const std::string UniqSuffix = ".__uniq.";
 408     auto pos = PGOFuncName.find(UniqSuffix);
 409     // Search '.' after ".__uniq." if ".__uniq." exists, otherwise
 410     // search '.' from the beginning.
 411     if (pos != std::string::npos)
 412       pos += UniqSuffix.length();
 413     else
 414       pos = 0;
 415     pos = PGOFuncName.find('.', pos);
 416     if (pos != std::string::npos && pos != 0) {
 417       const std::string &OtherFuncName = PGOFuncName.substr(0, pos);
 418       if (Error E = addFuncName(OtherFuncName))
 419         return E;
 420       MD5FuncMap.emplace_back(Function::getGUID(OtherFuncName), &F);
 421     }
 422   }
 423   Sorted = false;
 424   finalizeSymtab();
 425   return Error::success();
 426 }
 427
 428 uint64_t InstrProfSymtab::getFunctionHashFromAddress(uint64_t Address) {
 429   finalizeSymtab();
 430   auto It = partition_point(AddrToMD5Map, [=](std::pair<uint64_t, uint64_t> A) {
 431     return A.first < Address;
 432   });
 433   // Raw function pointer collected by value profiler may be from
 434   // external functions that are not instrumented. They won't have
 435   // mapping data to be used by the deserializer. Force the value to
 436   // be 0 in this case.
 437   if (It != AddrToMD5Map.end() && It->first == Address)
 438     return (uint64_t)It->second;
 439   return 0;
 440 }
 441
 442 Error collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,
 443                                 bool doCompression, std::string &Result) {
 444   assert(!NameStrs.empty() && "No name data to emit");
 445
 446   uint8_t Header[16], *P = Header;
 447   std::string UncompressedNameStrings =
 448       join(NameStrs.begin(), NameStrs.end(), getInstrProfNameSeparator());
 449
 450   assert(StringRef(UncompressedNameStrings)
 451                  .count(getInstrProfNameSeparator()) == (NameStrs.size() - 1) &&
 452          "PGO name is invalid (contains separator token)");
 453
 454   unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
 455   P += EncLen;
 456
 457   auto WriteStringToResult = [&](size_t CompressedLen, StringRef InputStr) {
 458     EncLen = encodeULEB128(CompressedLen, P);
 459     P += EncLen;
 460     char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
 461     unsigned HeaderLen = P - &Header[0];
 462     Result.append(HeaderStr, HeaderLen);
 463     Result += InputStr;
 464     return Error::success();
 465   };
 466
 467   if (!doCompression) {
 468     return WriteStringToResult(0, UncompressedNameStrings);
 469   }
 470
 471   SmallString<128> CompressedNameStrings;
 472   Error E = zlib::compress(StringRef(UncompressedNameStrings),
 473                            CompressedNameStrings, zlib::BestSizeCompression);
 474   if (E) {
 475     consumeError(std::move(E));
 476     return make_error<InstrProfError>(instrprof_error::compress_failed);
 477   }
 478
 479   return WriteStringToResult(CompressedNameStrings.size(),
 480                              CompressedNameStrings);
 481 }
 482
 483 StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar) {
 484   auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
 485   StringRef NameStr =
 486       Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
 487   return NameStr;
 488 }
 489
 490 Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
 491                                 std::string &Result, bool doCompression) {
 492   std::vector<std::string> NameStrs;
 493   for (auto *NameVar : NameVars) {
 494     NameStrs.push_back(std::string(getPGOFuncNameVarInitializer(NameVar)));
 495   }
 496   return collectPGOFuncNameStrings(
 497       NameStrs, zlib::isAvailable() && doCompression, Result);
 498 }
 499
 500 Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
 501   const uint8_t *P = NameStrings.bytes_begin();
 502   const uint8_t *EndP = NameStrings.bytes_end();
 503   while (P < EndP) {
 504     uint32_t N;
 505     uint64_t UncompressedSize = decodeULEB128(P, &N);
 506     P += N;
 507     uint64_t CompressedSize = decodeULEB128(P, &N);
 508     P += N;
 509     bool isCompressed = (CompressedSize != 0);
 510     SmallString<128> UncompressedNameStrings;
 511     StringRef NameStrings;
 512     if (isCompressed) {
 513       if (!llvm::zlib::isAvailable())
 514         return make_error<InstrProfError>(instrprof_error::zlib_unavailable);
 515
 516       StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
 517                                       CompressedSize);
 518       if (Error E =
 519               zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
 520                                UncompressedSize)) {
 521         consumeError(std::move(E));
 522         return make_error<InstrProfError>(instrprof_error::uncompress_failed);
 523       }
 524       P += CompressedSize;
 525       NameStrings = StringRef(UncompressedNameStrings.data(),
 526                               UncompressedNameStrings.size());
 527     } else {
 528       NameStrings =
 529           StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
 530       P += UncompressedSize;
 531     }
 532     // Now parse the name strings.
 533     SmallVector<StringRef, 0> Names;
 534     NameStrings.split(Names, getInstrProfNameSeparator());
 535     for (StringRef &Name : Names)
 536       if (Error E = Symtab.addFuncName(Name))
 537         return E;
 538
 539     while (P < EndP && *P == 0)
 540       P++;
 541   }
 542   return Error::success();
 543 }
 544
 545 void InstrProfRecord::accumulateCounts(CountSumOrPercent &Sum) const {
 546   uint64_t FuncSum = 0;
 547   Sum.NumEntries += Counts.size();
 548   for (uint64_t Count : Counts)
 549     FuncSum += Count;
 550   Sum.CountSum += FuncSum;
 551
 552   for (uint32_t VK = IPVK_First; VK <= IPVK_Last; ++VK) {
 553     uint64_t KindSum = 0;
 554     uint32_t NumValueSites = getNumValueSites(VK);
 555     for (size_t I = 0; I < NumValueSites; ++I) {
 556       uint32_t NV = getNumValueDataForSite(VK, I);
 557       std::unique_ptr<InstrProfValueData[]> VD = getValueForSite(VK, I);
 558       for (uint32_t V = 0; V < NV; V++)
 559         KindSum += VD[V].Count;
 560     }
 561     Sum.ValueCounts[VK] += KindSum;
 562   }
 563 }
 564
 565 void InstrProfValueSiteRecord::overlap(InstrProfValueSiteRecord &Input,
 566                                        uint32_t ValueKind,
 567                                        OverlapStats &Overlap,
 568                                        OverlapStats &FuncLevelOverlap) {
 569   this->sortByTargetValues();
 570   Input.sortByTargetValues();
 571   double Score = 0.0f, FuncLevelScore = 0.0f;
 572   auto I = ValueData.begin();
 573   auto IE = ValueData.end();
 574   auto J = Input.ValueData.begin();
 575   auto JE = Input.ValueData.end();
 576   while (I != IE && J != JE) {
 577     if (I->Value == J->Value) {
 578       Score += OverlapStats::score(I->Count, J->Count,
 579                                    Overlap.Base.ValueCounts[ValueKind],
 580                                    Overlap.Test.ValueCounts[ValueKind]);
 581       FuncLevelScore += OverlapStats::score(
 582           I->Count, J->Count, FuncLevelOverlap.Base.ValueCounts[ValueKind],
 583           FuncLevelOverlap.Test.ValueCounts[ValueKind]);
 584       ++I;
 585     } else if (I->Value < J->Value) {
 586       ++I;
 587       continue;
 588     }
 589     ++J;
 590   }
 591   Overlap.Overlap.ValueCounts[ValueKind] += Score;
 592   FuncLevelOverlap.Overlap.ValueCounts[ValueKind] += FuncLevelScore;
 593 }
 594
 595 // Return false on mismatch.
 596 void InstrProfRecord::overlapValueProfData(uint32_t ValueKind,
 597                                            InstrProfRecord &Other,
 598                                            OverlapStats &Overlap,
 599                                            OverlapStats &FuncLevelOverlap) {
 600   uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
 601   assert(ThisNumValueSites == Other.getNumValueSites(ValueKind));
 602   if (!ThisNumValueSites)
 603     return;
 604
 605   std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
 606       getOrCreateValueSitesForKind(ValueKind);
 607   MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
 608       Other.getValueSitesForKind(ValueKind);
 609   for (uint32_t I = 0; I < ThisNumValueSites; I++)
 610     ThisSiteRecords[I].overlap(OtherSiteRecords[I], ValueKind, Overlap,
 611                                FuncLevelOverlap);
 612 }
 613
 614 void InstrProfRecord::overlap(InstrProfRecord &Other, OverlapStats &Overlap,
 615                               OverlapStats &FuncLevelOverlap,
 616                               uint64_t ValueCutoff) {
 617   // FuncLevel CountSum for other should already computed and nonzero.
 618   assert(FuncLevelOverlap.Test.CountSum >= 1.0f);
 619   accumulateCounts(FuncLevelOverlap.Base);
 620   bool Mismatch = (Counts.size() != Other.Counts.size());
 621
 622   // Check if the value profiles mismatch.
 623   if (!Mismatch) {
 624     for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind) {
 625       uint32_t ThisNumValueSites = getNumValueSites(Kind);
 626       uint32_t OtherNumValueSites = Other.getNumValueSites(Kind);
 627       if (ThisNumValueSites != OtherNumValueSites) {
 628         Mismatch = true;
 629         break;
 630       }
 631     }
 632   }
 633   if (Mismatch) {
 634     Overlap.addOneMismatch(FuncLevelOverlap.Test);
 635     return;
 636   }
 637
 638   // Compute overlap for value counts.
 639   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
 640     overlapValueProfData(Kind, Other, Overlap, FuncLevelOverlap);
 641
 642   double Score = 0.0;
 643   uint64_t MaxCount = 0;
 644   // Compute overlap for edge counts.
 645   for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
 646     Score += OverlapStats::score(Counts[I], Other.Counts[I],
 647                                  Overlap.Base.CountSum, Overlap.Test.CountSum);
 648     MaxCount = std::max(Other.Counts[I], MaxCount);
 649   }
 650   Overlap.Overlap.CountSum += Score;
 651   Overlap.Overlap.NumEntries += 1;
 652
 653   if (MaxCount >= ValueCutoff) {
 654     double FuncScore = 0.0;
 655     for (size_t I = 0, E = Other.Counts.size(); I < E; ++I)
 656       FuncScore += OverlapStats::score(Counts[I], Other.Counts[I],
 657                                        FuncLevelOverlap.Base.CountSum,
 658                                        FuncLevelOverlap.Test.CountSum);
 659     FuncLevelOverlap.Overlap.CountSum = FuncScore;
 660     FuncLevelOverlap.Overlap.NumEntries = Other.Counts.size();
 661     FuncLevelOverlap.Valid = true;
 662   }
 663 }
 664
 665 void InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
 666                                      uint64_t Weight,
 667                                      function_ref<void(instrprof_error)> Warn) {
 668   this->sortByTargetValues();
 669   Input.sortByTargetValues();
 670   auto I = ValueData.begin();
 671   auto IE = ValueData.end();
 672   for (const InstrProfValueData &J : Input.ValueData) {
 673     while (I != IE && I->Value < J.Value)
 674       ++I;
 675     if (I != IE && I->Value == J.Value) {
 676       bool Overflowed;
 677       I->Count = SaturatingMultiplyAdd(J.Count, Weight, I->Count, &Overflowed);
 678       if (Overflowed)
 679         Warn(instrprof_error::counter_overflow);
 680       ++I;
 681       continue;
 682     }
 683     ValueData.insert(I, J);
 684   }
 685 }
 686
 687 void InstrProfValueSiteRecord::scale(uint64_t N, uint64_t D,
 688                                      function_ref<void(instrprof_error)> Warn) {
 689   for (InstrProfValueData &I : ValueData) {
 690     bool Overflowed;
 691     I.Count = SaturatingMultiply(I.Count, N, &Overflowed) / D;
 692     if (Overflowed)
 693       Warn(instrprof_error::counter_overflow);
 694   }
 695 }
 696
 697 // Merge Value Profile data from Src record to this record for ValueKind.
 698 // Scale merged value counts by \p Weight.
 699 void InstrProfRecord::mergeValueProfData(
 700     uint32_t ValueKind, InstrProfRecord &Src, uint64_t Weight,
 701     function_ref<void(instrprof_error)> Warn) {
 702   uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
 703   uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
 704   if (ThisNumValueSites != OtherNumValueSites) {
 705     Warn(instrprof_error::value_site_count_mismatch);
 706     return;
 707   }
 708   if (!ThisNumValueSites)
 709     return;
 710   std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
 711       getOrCreateValueSitesForKind(ValueKind);
 712   MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
 713       Src.getValueSitesForKind(ValueKind);
 714   for (uint32_t I = 0; I < ThisNumValueSites; I++)
 715     ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight, Warn);
 716 }
 717
 718 void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
 719                             function_ref<void(instrprof_error)> Warn) {
 720   // If the number of counters doesn't match we either have bad data
 721   // or a hash collision.
 722   if (Counts.size() != Other.Counts.size()) {
 723     Warn(instrprof_error::count_mismatch);
 724     return;
 725   }
 726
 727   for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
 728     bool Overflowed;
 729     Counts[I] =
 730         SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
 731     if (Overflowed)
 732       Warn(instrprof_error::counter_overflow);
 733   }
 734
 735   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
 736     mergeValueProfData(Kind, Other, Weight, Warn);
 737 }
 738
 739 void InstrProfRecord::scaleValueProfData(
 740     uint32_t ValueKind, uint64_t N, uint64_t D,
 741     function_ref<void(instrprof_error)> Warn) {
 742   for (auto &R : getValueSitesForKind(ValueKind))
 743     R.scale(N, D, Warn);
 744 }
 745
 746 void InstrProfRecord::scale(uint64_t N, uint64_t D,
 747                             function_ref<void(instrprof_error)> Warn) {
 748   assert(D != 0 && "D cannot be 0");
 749   for (auto &Count : this->Counts) {
 750     bool Overflowed;
 751     Count = SaturatingMultiply(Count, N, &Overflowed) / D;
 752     if (Overflowed)
 753       Warn(instrprof_error::counter_overflow);
 754   }
 755   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
 756     scaleValueProfData(Kind, N, D, Warn);
 757 }
 758
 759 // Map indirect call target name hash to name string.
 760 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
 761                                      InstrProfSymtab *SymTab) {
 762   if (!SymTab)
 763     return Value;
 764
 765   if (ValueKind == IPVK_IndirectCallTarget)
 766     return SymTab->getFunctionHashFromAddress(Value);
 767
 768   return Value;
 769 }
 770
 771 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
 772                                    InstrProfValueData *VData, uint32_t N,
 773                                    InstrProfSymtab *ValueMap) {
 774   for (uint32_t I = 0; I < N; I++) {
 775     VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
 776   }
 777   std::vector<InstrProfValueSiteRecord> &ValueSites =
 778       getOrCreateValueSitesForKind(ValueKind);
 779   if (N == 0)
 780     ValueSites.emplace_back();
 781   else
 782     ValueSites.emplace_back(VData, VData + N);
 783 }
 784
 785 #define INSTR_PROF_COMMON_API_IMPL
 786 #include "llvm/ProfileData/InstrProfData.inc"
 787
 788 /*!
 789  * ValueProfRecordClosure Interface implementation for  InstrProfRecord
 790  *  class. These C wrappers are used as adaptors so that C++ code can be
 791  *  invoked as callbacks.
 792  */
 793 uint32_t getNumValueKindsInstrProf(const void *Record) {
 794   return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
 795 }
 796
 797 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
 798   return reinterpret_cast<const InstrProfRecord *>(Record)
 799       ->getNumValueSites(VKind);
 800 }
 801
 802 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
 803   return reinterpret_cast<const InstrProfRecord *>(Record)
 804       ->getNumValueData(VKind);
 805 }
 806
 807 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
 808                                          uint32_t S) {
 809   return reinterpret_cast<const InstrProfRecord *>(R)
 810       ->getNumValueDataForSite(VK, S);
 811 }
 812
 813 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
 814                               uint32_t K, uint32_t S) {
 815   reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(Dst, K, S);
 816 }
 817
 818 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
 819   ValueProfData *VD =
 820       (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
 821   memset(VD, 0, TotalSizeInBytes);
 822   return VD;
 823 }
 824
 825 static ValueProfRecordClosure InstrProfRecordClosure = {
 826     nullptr,
 827     getNumValueKindsInstrProf,
 828     getNumValueSitesInstrProf,
 829     getNumValueDataInstrProf,
 830     getNumValueDataForSiteInstrProf,
 831     nullptr,
 832     getValueForSiteInstrProf,
 833     allocValueProfDataInstrProf};
 834
 835 // Wrapper implementation using the closure mechanism.
 836 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
 837   auto Closure = InstrProfRecordClosure;
 838   Closure.Record = &Record;
 839   return getValueProfDataSize(&Closure);
 840 }
 841
 842 // Wrapper implementation using the closure mechanism.
 843 std::unique_ptr<ValueProfData>
 844 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
 845   InstrProfRecordClosure.Record = &Record;
 846
 847   std::unique_ptr<ValueProfData> VPD(
 848       serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
 849   return VPD;
 850 }
 851
 852 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
 853                                     InstrProfSymtab *SymTab) {
 854   Record.reserveSites(Kind, NumValueSites);
 855
 856   InstrProfValueData *ValueData = getValueProfRecordValueData(this);
 857   for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
 858     uint8_t ValueDataCount = this->SiteCountArray[VSite];
 859     Record.addValueData(Kind, VSite, ValueData, ValueDataCount, SymTab);
 860     ValueData += ValueDataCount;
 861   }
 862 }
 863
 864 // For writing/serializing,  Old is the host endianness, and  New is
 865 // byte order intended on disk. For Reading/deserialization, Old
 866 // is the on-disk source endianness, and New is the host endianness.
 867 void ValueProfRecord::swapBytes(support::endianness Old,
 868                                 support::endianness New) {
 869   using namespace support;
 870
 871   if (Old == New)
 872     return;
 873
 874   if (getHostEndianness() != Old) {
 875     sys::swapByteOrder<uint32_t>(NumValueSites);
 876     sys::swapByteOrder<uint32_t>(Kind);
 877   }
 878   uint32_t ND = getValueProfRecordNumValueData(this);
 879   InstrProfValueData *VD = getValueProfRecordValueData(this);
 880
 881   // No need to swap byte array: SiteCountArrray.
 882   for (uint32_t I = 0; I < ND; I++) {
 883     sys::swapByteOrder<uint64_t>(VD[I].Value);
 884     sys::swapByteOrder<uint64_t>(VD[I].Count);
 885   }
 886   if (getHostEndianness() == Old) {
 887     sys::swapByteOrder<uint32_t>(NumValueSites);
 888     sys::swapByteOrder<uint32_t>(Kind);
 889   }
 890 }
 891
 892 void ValueProfData::deserializeTo(InstrProfRecord &Record,
 893                                   InstrProfSymtab *SymTab) {
 894   if (NumValueKinds == 0)
 895     return;
 896
 897   ValueProfRecord *VR = getFirstValueProfRecord(this);
 898   for (uint32_t K = 0; K < NumValueKinds; K++) {
 899     VR->deserializeTo(Record, SymTab);
 900     VR = getValueProfRecordNext(VR);
 901   }
 902 }
 903
 904 template <class T>
 905 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
 906   using namespace support;
 907
 908   if (Orig == little)
 909     return endian::readNext<T, little, unaligned>(D);
 910   else
 911     return endian::readNext<T, big, unaligned>(D);
 912 }
 913
 914 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
 915   return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
 916                                             ValueProfData());
 917 }
 918
 919 Error ValueProfData::checkIntegrity() {
 920   if (NumValueKinds > IPVK_Last + 1)
 921     return make_error<InstrProfError>(
 922         instrprof_error::malformed, "number of value profile kinds is invalid");
 923   // Total size needs to be multiple of quadword size.
 924   if (TotalSize % sizeof(uint64_t))
 925     return make_error<InstrProfError>(
 926         instrprof_error::malformed, "total size is not multiples of quardword");
 927
 928   ValueProfRecord *VR = getFirstValueProfRecord(this);
 929   for (uint32_t K = 0; K < this->NumValueKinds; K++) {
 930     if (VR->Kind > IPVK_Last)
 931       return make_error<InstrProfError>(instrprof_error::malformed,
 932                                         "value kind is invalid");
 933     VR = getValueProfRecordNext(VR);
 934     if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
 935       return make_error<InstrProfError>(
 936           instrprof_error::malformed,
 937           "value profile address is greater than total size");
 938   }
 939   return Error::success();
 940 }
 941
 942 Expected<std::unique_ptr<ValueProfData>>
 943 ValueProfData::getValueProfData(const unsigned char *D,
 944                                 const unsigned char *const BufferEnd,
 945                                 support::endianness Endianness) {
 946   using namespace support;
 947
 948   if (D + sizeof(ValueProfData) > BufferEnd)
 949     return make_error<InstrProfError>(instrprof_error::truncated);
 950
 951   const unsigned char *Header = D;
 952   uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
 953   if (D + TotalSize > BufferEnd)
 954     return make_error<InstrProfError>(instrprof_error::too_large);
 955
 956   std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
 957   memcpy(VPD.get(), D, TotalSize);
 958   // Byte swap.
 959   VPD->swapBytesToHost(Endianness);
 960
 961   Error E = VPD->checkIntegrity();
 962   if (E)
 963     return std::move(E);
 964
 965   return std::move(VPD);
 966 }
 967
 968 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
 969   using namespace support;
 970
 971   if (Endianness == getHostEndianness())
 972     return;
 973
 974   sys::swapByteOrder<uint32_t>(TotalSize);
 975   sys::swapByteOrder<uint32_t>(NumValueKinds);
 976
 977   ValueProfRecord *VR = getFirstValueProfRecord(this);
 978   for (uint32_t K = 0; K < NumValueKinds; K++) {
 979     VR->swapBytes(Endianness, getHostEndianness());
 980     VR = getValueProfRecordNext(VR);
 981   }
 982 }
 983
 984 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
 985   using namespace support;
 986
 987   if (Endianness == getHostEndianness())
 988     return;
 989
 990   ValueProfRecord *VR = getFirstValueProfRecord(this);
 991   for (uint32_t K = 0; K < NumValueKinds; K++) {
 992     ValueProfRecord *NVR = getValueProfRecordNext(VR);
 993     VR->swapBytes(getHostEndianness(), Endianness);
 994     VR = NVR;
 995   }
 996   sys::swapByteOrder<uint32_t>(TotalSize);
 997   sys::swapByteOrder<uint32_t>(NumValueKinds);
 998 }
 999
1000 void annotateValueSite(Module &M, Instruction &Inst,
1001                        const InstrProfRecord &InstrProfR,
1002                        InstrProfValueKind ValueKind, uint32_t SiteIdx,
1003                        uint32_t MaxMDCount) {
1004   uint32_t NV = InstrProfR.getNumValueDataForSite(ValueKind, SiteIdx);
1005   if (!NV)
1006     return;
1007
1008   uint64_t Sum = 0;
1009   std::unique_ptr<InstrProfValueData[]> VD =
1010       InstrProfR.getValueForSite(ValueKind, SiteIdx, &Sum);
1011
1012   ArrayRef<InstrProfValueData> VDs(VD.get(), NV);
1013   annotateValueSite(M, Inst, VDs, Sum, ValueKind, MaxMDCount);
1014 }
1015
1016 void annotateValueSite(Module &M, Instruction &Inst,
1017                        ArrayRef<InstrProfValueData> VDs,
1018                        uint64_t Sum, InstrProfValueKind ValueKind,
1019                        uint32_t MaxMDCount) {
1020   LLVMContext &Ctx = M.getContext();
1021   MDBuilder MDHelper(Ctx);
1022   SmallVector<Metadata *, 3> Vals;
1023   // Tag
1024   Vals.push_back(MDHelper.createString("VP"));
1025   // Value Kind
1026   Vals.push_back(MDHelper.createConstant(
1027       ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
1028   // Total Count
1029   Vals.push_back(
1030       MDHelper.createConstant(ConstantInt::get(Type::getInt64Ty(Ctx), Sum)));
1031
1032   // Value Profile Data
1033   uint32_t MDCount = MaxMDCount;
1034   for (auto &VD : VDs) {
1035     Vals.push_back(MDHelper.createConstant(
1036         ConstantInt::get(Type::getInt64Ty(Ctx), VD.Value)));
1037     Vals.push_back(MDHelper.createConstant(
1038         ConstantInt::get(Type::getInt64Ty(Ctx), VD.Count)));
1039     if (--MDCount == 0)
1040       break;
1041   }
1042   Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
1043 }
1044
1045 bool getValueProfDataFromInst(const Instruction &Inst,
1046                               InstrProfValueKind ValueKind,
1047                               uint32_t MaxNumValueData,
1048                               InstrProfValueData ValueData[],
1049                               uint32_t &ActualNumValueData, uint64_t &TotalC,
1050                               bool GetNoICPValue) {
1051   MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
1052   if (!MD)
1053     return false;
1054
1055   unsigned NOps = MD->getNumOperands();
1056
1057   if (NOps < 5)
1058     return false;
1059
1060   // Operand 0 is a string tag "VP":
1061   MDString *Tag = cast<MDString>(MD->getOperand(0));
1062   if (!Tag)
1063     return false;
1064
1065   if (!Tag->getString().equals("VP"))
1066     return false;
1067
1068   // Now check kind:
1069   ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
1070   if (!KindInt)
1071     return false;
1072   if (KindInt->getZExtValue() != ValueKind)
1073     return false;
1074
1075   // Get total count
1076   ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
1077   if (!TotalCInt)
1078     return false;
1079   TotalC = TotalCInt->getZExtValue();
1080
1081   ActualNumValueData = 0;
1082
1083   for (unsigned I = 3; I < NOps; I += 2) {
1084     if (ActualNumValueData >= MaxNumValueData)
1085       break;
1086     ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
1087     ConstantInt *Count =
1088         mdconst::dyn_extract<ConstantInt>(MD->getOperand(I + 1));
1089     if (!Value || !Count)
1090       return false;
1091     uint64_t CntValue = Count->getZExtValue();
1092     if (!GetNoICPValue && (CntValue == NOMORE_ICP_MAGICNUM))
1093       continue;
1094     ValueData[ActualNumValueData].Value = Value->getZExtValue();
1095     ValueData[ActualNumValueData].Count = CntValue;
1096     ActualNumValueData++;
1097   }
1098   return true;
1099 }
1100
1101 MDNode *getPGOFuncNameMetadata(const Function &F) {
1102   return F.getMetadata(getPGOFuncNameMetadataName());
1103 }
1104
1105 void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
1106   // Only for internal linkage functions.
1107   if (PGOFuncName == F.getName())
1108       return;
1109   // Don't create duplicated meta-data.
1110   if (getPGOFuncNameMetadata(F))
1111     return;
1112   LLVMContext &C = F.getContext();
1113   MDNode *N = MDNode::get(C, MDString::get(C, PGOFuncName));
1114   F.setMetadata(getPGOFuncNameMetadataName(), N);
1115 }
1116
1117 bool needsComdatForCounter(const Function &F, const Module &M) {
1118   if (F.hasComdat())
1119     return true;
1120
1121   if (!Triple(M.getTargetTriple()).supportsCOMDAT())
1122     return false;
1123
1124   // See createPGOFuncNameVar for more details. To avoid link errors, profile
1125   // counters for function with available_externally linkage needs to be changed
1126   // to linkonce linkage. On ELF based systems, this leads to weak symbols to be
1127   // created. Without using comdat, duplicate entries won't be removed by the
1128   // linker leading to increased data segement size and raw profile size. Even
1129   // worse, since the referenced counter from profile per-function data object
1130   // will be resolved to the common strong definition, the profile counts for
1131   // available_externally functions will end up being duplicated in raw profile
1132   // data. This can result in distorted profile as the counts of those dups
1133   // will be accumulated by the profile merger.
1134   GlobalValue::LinkageTypes Linkage = F.getLinkage();
1135   if (Linkage != GlobalValue::ExternalWeakLinkage &&
1136       Linkage != GlobalValue::AvailableExternallyLinkage)
1137     return false;
1138
1139   return true;
1140 }
1141
1142 // Check if INSTR_PROF_RAW_VERSION_VAR is defined.
1143 bool isIRPGOFlagSet(const Module *M) {
1144   auto IRInstrVar =
1145       M->getNamedGlobal(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
1146   if (!IRInstrVar || IRInstrVar->hasLocalLinkage())
1147     return false;
1148
1149   // For CSPGO+LTO, this variable might be marked as non-prevailing and we only
1150   // have the decl.
1151   if (IRInstrVar->isDeclaration())
1152     return true;
1153
1154   // Check if the flag is set.
1155   if (!IRInstrVar->hasInitializer())
1156     return false;
1157
1158   auto *InitVal = dyn_cast_or_null<ConstantInt>(IRInstrVar->getInitializer());
1159   if (!InitVal)
1160     return false;
1161   return (InitVal->getZExtValue() & VARIANT_MASK_IR_PROF) != 0;
1162 }
1163
1164 // Check if we can safely rename this Comdat function.
1165 bool canRenameComdatFunc(const Function &F, bool CheckAddressTaken) {
1166   if (F.getName().empty())
1167     return false;
1168   if (!needsComdatForCounter(F, *(F.getParent())))
1169     return false;
1170   // Unsafe to rename the address-taken function (which can be used in
1171   // function comparison).
1172   if (CheckAddressTaken && F.hasAddressTaken())
1173     return false;
1174   // Only safe to do if this function may be discarded if it is not used
1175   // in the compilation unit.
1176   if (!GlobalValue::isDiscardableIfUnused(F.getLinkage()))
1177     return false;
1178
1179   // For AvailableExternallyLinkage functions.
1180   if (!F.hasComdat()) {
1181     assert(F.getLinkage() == GlobalValue::AvailableExternallyLinkage);
1182     return true;
1183   }
1184   return true;
1185 }
1186
1187 // Create a COMDAT variable INSTR_PROF_RAW_VERSION_VAR to make the runtime
1188 // aware this is an ir_level profile so it can set the version flag.
1189 GlobalVariable *createIRLevelProfileFlagVar(Module &M, bool IsCS,
1190                                             bool InstrEntryBBEnabled,
1191                                             bool DebugInfoCorrelate) {
1192   const StringRef VarName(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
1193   Type *IntTy64 = Type::getInt64Ty(M.getContext());
1194   uint64_t ProfileVersion = (INSTR_PROF_RAW_VERSION | VARIANT_MASK_IR_PROF);
1195   if (IsCS)
1196     ProfileVersion |= VARIANT_MASK_CSIR_PROF;
1197   if (InstrEntryBBEnabled)
1198     ProfileVersion |= VARIANT_MASK_INSTR_ENTRY;
1199   if (DebugInfoCorrelate)
1200     ProfileVersion |= VARIANT_MASK_DBG_CORRELATE;
1201   auto IRLevelVersionVariable = new GlobalVariable(
1202       M, IntTy64, true, GlobalValue::WeakAnyLinkage,
1203       Constant::getIntegerValue(IntTy64, APInt(64, ProfileVersion)), VarName);
1204   IRLevelVersionVariable->setVisibility(GlobalValue::DefaultVisibility);
1205   Triple TT(M.getTargetTriple());
1206   if (TT.supportsCOMDAT()) {
1207     IRLevelVersionVariable->setLinkage(GlobalValue::ExternalLinkage);
1208     IRLevelVersionVariable->setComdat(M.getOrInsertComdat(VarName));
1209   }
1210   return IRLevelVersionVariable;
1211 }
1212
1213 // Create the variable for the profile file name.
1214 void createProfileFileNameVar(Module &M, StringRef InstrProfileOutput) {
1215   if (InstrProfileOutput.empty())
1216     return;
1217   Constant *ProfileNameConst =
1218       ConstantDataArray::getString(M.getContext(), InstrProfileOutput, true);
1219   GlobalVariable *ProfileNameVar = new GlobalVariable(
1220       M, ProfileNameConst->getType(), true, GlobalValue::WeakAnyLinkage,
1221       ProfileNameConst, INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR));
1222   Triple TT(M.getTargetTriple());
1223   if (TT.supportsCOMDAT()) {
1224     ProfileNameVar->setLinkage(GlobalValue::ExternalLinkage);
1225     ProfileNameVar->setComdat(M.getOrInsertComdat(
1226         StringRef(INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR))));
1227   }
1228 }
1229
1230 Error OverlapStats::accumulateCounts(const std::string &BaseFilename,
1231                                      const std::string &TestFilename,
1232                                      bool IsCS) {
1233   auto getProfileSum = [IsCS](const std::string &Filename,
1234                               CountSumOrPercent &Sum) -> Error {
1235     auto ReaderOrErr = InstrProfReader::create(Filename);
1236     if (Error E = ReaderOrErr.takeError()) {
1237       return E;
1238     }
1239     auto Reader = std::move(ReaderOrErr.get());
1240     Reader->accumulateCounts(Sum, IsCS);
1241     return Error::success();
1242   };
1243   auto Ret = getProfileSum(BaseFilename, Base);
1244   if (Ret)
1245     return Ret;
1246   Ret = getProfileSum(TestFilename, Test);
1247   if (Ret)
1248     return Ret;
1249   this->BaseFilename = &BaseFilename;
1250   this->TestFilename = &TestFilename;
1251   Valid = true;
1252   return Error::success();
1253 }
1254
1255 void OverlapStats::addOneMismatch(const CountSumOrPercent &MismatchFunc) {
1256   Mismatch.NumEntries += 1;
1257   Mismatch.CountSum += MismatchFunc.CountSum / Test.CountSum;
1258   for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1259     if (Test.ValueCounts[I] >= 1.0f)
1260       Mismatch.ValueCounts[I] +=
1261           MismatchFunc.ValueCounts[I] / Test.ValueCounts[I];
1262   }
1263 }
1264
1265 void OverlapStats::addOneUnique(const CountSumOrPercent &UniqueFunc) {
1266   Unique.NumEntries += 1;
1267   Unique.CountSum += UniqueFunc.CountSum / Test.CountSum;
1268   for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1269     if (Test.ValueCounts[I] >= 1.0f)
1270       Unique.ValueCounts[I] += UniqueFunc.ValueCounts[I] / Test.ValueCounts[I];
1271   }
1272 }
1273
1274 void OverlapStats::dump(raw_fd_ostream &OS) const {
1275   if (!Valid)
1276     return;
1277
1278   const char *EntryName =
1279       (Level == ProgramLevel ? "functions" : "edge counters");
1280   if (Level == ProgramLevel) {
1281     OS << "Profile overlap infomation for base_profile: " << *BaseFilename
1282        << " and test_profile: " << *TestFilename << "\nProgram level:\n";
1283   } else {
1284     OS << "Function level:\n"
1285        << "  Function: " << FuncName << " (Hash=" << FuncHash << ")\n";
1286   }
1287
1288   OS << "  # of " << EntryName << " overlap: " << Overlap.NumEntries << "\n";
1289   if (Mismatch.NumEntries)
1290     OS << "  # of " << EntryName << " mismatch: " << Mismatch.NumEntries
1291        << "\n";
1292   if (Unique.NumEntries)
1293     OS << "  # of " << EntryName
1294        << " only in test_profile: " << Unique.NumEntries << "\n";
1295
1296   OS << "  Edge profile overlap: " << format("%.3f%%", Overlap.CountSum * 100)
1297      << "\n";
1298   if (Mismatch.NumEntries)
1299     OS << "  Mismatched count percentage (Edge): "
1300        << format("%.3f%%", Mismatch.CountSum * 100) << "\n";
1301   if (Unique.NumEntries)
1302     OS << "  Percentage of Edge profile only in test_profile: "
1303        << format("%.3f%%", Unique.CountSum * 100) << "\n";
1304   OS << "  Edge profile base count sum: " << format("%.0f", Base.CountSum)
1305      << "\n"
1306      << "  Edge profile test count sum: " << format("%.0f", Test.CountSum)
1307      << "\n";
1308
1309   for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1310     if (Base.ValueCounts[I] < 1.0f && Test.ValueCounts[I] < 1.0f)
1311       continue;
1312     char ProfileKindName[20];
1313     switch (I) {
1314     case IPVK_IndirectCallTarget:
1315       strncpy(ProfileKindName, "IndirectCall", 19);
1316       break;
1317     case IPVK_MemOPSize:
1318       strncpy(ProfileKindName, "MemOP", 19);
1319       break;
1320     default:
1321       snprintf(ProfileKindName, 19, "VP[%d]", I);
1322       break;
1323     }
1324     OS << "  " << ProfileKindName
1325        << " profile overlap: " << format("%.3f%%", Overlap.ValueCounts[I] * 100)
1326        << "\n";
1327     if (Mismatch.NumEntries)
1328       OS << "  Mismatched count percentage (" << ProfileKindName
1329          << "): " << format("%.3f%%", Mismatch.ValueCounts[I] * 100) << "\n";
1330     if (Unique.NumEntries)
1331       OS << "  Percentage of " << ProfileKindName
1332          << " profile only in test_profile: "
1333          << format("%.3f%%", Unique.ValueCounts[I] * 100) << "\n";
1334     OS << "  " << ProfileKindName
1335        << " profile base count sum: " << format("%.0f", Base.ValueCounts[I])
1336        << "\n"
1337        << "  " << ProfileKindName
1338        << " profile test count sum: " << format("%.0f", Test.ValueCounts[I])
1339        << "\n";
1340   }
1341 }
1342
1343 } // end namespace llvm