1//=-- InstrProf.cpp - Instrumented profiling format support -----------------=//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains support for clang's instrumentation based PGO and
11// coverage.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/ProfileData/InstrProf.h"
16#include "llvm/ADT/StringExtras.h"
17#include "llvm/IR/Constants.h"
18#include "llvm/IR/Function.h"
19#include "llvm/IR/GlobalVariable.h"
20#include "llvm/IR/MDBuilder.h"
21#include "llvm/IR/Module.h"
22#include "llvm/Support/Compression.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/LEB128.h"
25#include "llvm/Support/ManagedStatic.h"
26#include "llvm/Support/Path.h"
27
28using namespace llvm;
29
30static cl::opt<bool> StaticFuncFullModulePrefix(
31    "static-func-full-module-prefix", cl::init(false),
32    cl::desc("Use full module build paths in the profile counter names for "
33             "static functions."));
34
35namespace {
36std::string getInstrProfErrString(instrprof_error Err) {
37  switch (Err) {
38  case instrprof_error::success:
39    return "Success";
40  case instrprof_error::eof:
41    return "End of File";
42  case instrprof_error::unrecognized_format:
43    return "Unrecognized instrumentation profile encoding format";
44  case instrprof_error::bad_magic:
45    return "Invalid instrumentation profile data (bad magic)";
46  case instrprof_error::bad_header:
47    return "Invalid instrumentation profile data (file header is corrupt)";
48  case instrprof_error::unsupported_version:
49    return "Unsupported instrumentation profile format version";
50  case instrprof_error::unsupported_hash_type:
51    return "Unsupported instrumentation profile hash type";
52  case instrprof_error::too_large:
53    return "Too much profile data";
54  case instrprof_error::truncated:
55    return "Truncated profile data";
56  case instrprof_error::malformed:
57    return "Malformed instrumentation profile data";
58  case instrprof_error::unknown_function:
59    return "No profile data available for function";
60  case instrprof_error::hash_mismatch:
61    return "Function control flow change detected (hash mismatch)";
62  case instrprof_error::count_mismatch:
63    return "Function basic block count change detected (counter mismatch)";
64  case instrprof_error::counter_overflow:
65    return "Counter overflow";
66  case instrprof_error::value_site_count_mismatch:
67    return "Function value site count change detected (counter mismatch)";
68  case instrprof_error::compress_failed:
69    return "Failed to compress data (zlib)";
70  case instrprof_error::uncompress_failed:
71    return "Failed to uncompress data (zlib)";
72  }
73  llvm_unreachable("A value of instrprof_error has no message.");
74}
75
76// FIXME: This class is only here to support the transition to llvm::Error. It
77// will be removed once this transition is complete. Clients should prefer to
78// deal with the Error value directly, rather than converting to error_code.
79class InstrProfErrorCategoryType : public std::error_category {
80  const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
81  std::string message(int IE) const override {
82    return getInstrProfErrString(static_cast<instrprof_error>(IE));
83  }
84};
85} // end anonymous namespace
86
87static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
88
89const std::error_category &llvm::instrprof_category() {
90  return *ErrorCategory;
91}
92
93namespace llvm {
94
95void SoftInstrProfErrors::addError(instrprof_error IE) {
96  if (IE == instrprof_error::success)
97    return;
98
99  if (FirstError == instrprof_error::success)
100    FirstError = IE;
101
102  switch (IE) {
103  case instrprof_error::hash_mismatch:
104    ++NumHashMismatches;
105    break;
106  case instrprof_error::count_mismatch:
107    ++NumCountMismatches;
108    break;
109  case instrprof_error::counter_overflow:
110    ++NumCounterOverflows;
111    break;
112  case instrprof_error::value_site_count_mismatch:
113    ++NumValueSiteCountMismatches;
114    break;
115  default:
116    llvm_unreachable("Not a soft error");
117  }
118}
119
120std::string InstrProfError::message() const {
121  return getInstrProfErrString(Err);
122}
123
124char InstrProfError::ID = 0;
125
126std::string getPGOFuncName(StringRef RawFuncName,
127                           GlobalValue::LinkageTypes Linkage,
128                           StringRef FileName,
129                           uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
130  return GlobalValue::getGlobalIdentifier(RawFuncName, Linkage, FileName);
131}
132
133// Return the PGOFuncName. This function has some special handling when called
134// in LTO optimization. The following only applies when calling in LTO passes
135// (when \c InLTO is true): LTO's internalization privatizes many global linkage
136// symbols. This happens after value profile annotation, but those internal
137// linkage functions should not have a source prefix.
138// To differentiate compiler generated internal symbols from original ones,
139// PGOFuncName meta data are created and attached to the original internal
140// symbols in the value profile annotation step
141// (PGOUseFunc::annotateIndirectCallSites). If a symbol does not have the meta
142// data, its original linkage must be non-internal.
143std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
144  if (!InLTO) {
145    StringRef FileName = (StaticFuncFullModulePrefix
146                              ? F.getParent()->getName()
147                              : sys::path::filename(F.getParent()->getName()));
148    return getPGOFuncName(F.getName(), F.getLinkage(), FileName, Version);
149  }
150
151  // In LTO mode (when InLTO is true), first check if there is a meta data.
152  if (MDNode *MD = getPGOFuncNameMetadata(F)) {
153    StringRef S = cast<MDString>(MD->getOperand(0))->getString();
154    return S.str();
155  }
156
157  // If there is no meta data, the function must be a global before the value
158  // profile annotation pass. Its current linkage may be internal if it is
159  // internalized in LTO mode.
160  return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
161}
162
163StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
164  if (FileName.empty())
165    return PGOFuncName;
166  // Drop the file name including ':'. See also getPGOFuncName.
167  if (PGOFuncName.startswith(FileName))
168    PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
169  return PGOFuncName;
170}
171
172// \p FuncName is the string used as profile lookup key for the function. A
173// symbol is created to hold the name. Return the legalized symbol name.
174std::string getPGOFuncNameVarName(StringRef FuncName,
175                                  GlobalValue::LinkageTypes Linkage) {
176  std::string VarName = getInstrProfNameVarPrefix();
177  VarName += FuncName;
178
179  if (!GlobalValue::isLocalLinkage(Linkage))
180    return VarName;
181
182  // Now fix up illegal chars in local VarName that may upset the assembler.
183  const char *InvalidChars = "-:<>/\"'";
184  size_t found = VarName.find_first_of(InvalidChars);
185  while (found != std::string::npos) {
186    VarName[found] = '_';
187    found = VarName.find_first_of(InvalidChars, found + 1);
188  }
189  return VarName;
190}
191
192GlobalVariable *createPGOFuncNameVar(Module &M,
193                                     GlobalValue::LinkageTypes Linkage,
194                                     StringRef PGOFuncName) {
195
196  // We generally want to match the function's linkage, but available_externally
197  // and extern_weak both have the wrong semantics, and anything that doesn't
198  // need to link across compilation units doesn't need to be visible at all.
199  if (Linkage == GlobalValue::ExternalWeakLinkage)
200    Linkage = GlobalValue::LinkOnceAnyLinkage;
201  else if (Linkage == GlobalValue::AvailableExternallyLinkage)
202    Linkage = GlobalValue::LinkOnceODRLinkage;
203  else if (Linkage == GlobalValue::InternalLinkage ||
204           Linkage == GlobalValue::ExternalLinkage)
205    Linkage = GlobalValue::PrivateLinkage;
206
207  auto *Value =
208      ConstantDataArray::getString(M.getContext(), PGOFuncName, false);
209  auto FuncNameVar =
210      new GlobalVariable(M, Value->getType(), true, Linkage, Value,
211                         getPGOFuncNameVarName(PGOFuncName, Linkage));
212
213  // Hide the symbol so that we correctly get a copy for each executable.
214  if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
215    FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
216
217  return FuncNameVar;
218}
219
220GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName) {
221  return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), PGOFuncName);
222}
223
224void InstrProfSymtab::create(Module &M, bool InLTO) {
225  for (Function &F : M) {
226    // Function may not have a name: like using asm("") to overwrite the name.
227    // Ignore in this case.
228    if (!F.hasName())
229      continue;
230    const std::string &PGOFuncName = getPGOFuncName(F, InLTO);
231    addFuncName(PGOFuncName);
232    MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
233  }
234
235  finalizeSymtab();
236}
237
238Error collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
239                                bool doCompression, std::string &Result) {
240  assert(NameStrs.size() && "No name data to emit");
241
242  uint8_t Header[16], *P = Header;
243  std::string UncompressedNameStrings =
244      join(NameStrs.begin(), NameStrs.end(), getInstrProfNameSeparator());
245
246  assert(StringRef(UncompressedNameStrings)
247                 .count(getInstrProfNameSeparator()) == (NameStrs.size() - 1) &&
248         "PGO name is invalid (contains separator token)");
249
250  unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
251  P += EncLen;
252
253  auto WriteStringToResult = [&](size_t CompressedLen, StringRef InputStr) {
254    EncLen = encodeULEB128(CompressedLen, P);
255    P += EncLen;
256    char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
257    unsigned HeaderLen = P - &Header[0];
258    Result.append(HeaderStr, HeaderLen);
259    Result += InputStr;
260    return Error::success();
261  };
262
263  if (!doCompression) {
264    return WriteStringToResult(0, UncompressedNameStrings);
265  }
266
267  SmallString<128> CompressedNameStrings;
268  zlib::Status Success =
269      zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
270                     zlib::BestSizeCompression);
271
272  if (Success != zlib::StatusOK)
273    return make_error<InstrProfError>(instrprof_error::compress_failed);
274
275  return WriteStringToResult(CompressedNameStrings.size(),
276                             CompressedNameStrings);
277}
278
279StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar) {
280  auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
281  StringRef NameStr =
282      Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
283  return NameStr;
284}
285
286Error collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
287                                std::string &Result, bool doCompression) {
288  std::vector<std::string> NameStrs;
289  for (auto *NameVar : NameVars) {
290    NameStrs.push_back(getPGOFuncNameVarInitializer(NameVar));
291  }
292  return collectPGOFuncNameStrings(
293      NameStrs, zlib::isAvailable() && doCompression, Result);
294}
295
296Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
297  const uint8_t *P = reinterpret_cast<const uint8_t *>(NameStrings.data());
298  const uint8_t *EndP = reinterpret_cast<const uint8_t *>(NameStrings.data() +
299                                                          NameStrings.size());
300  while (P < EndP) {
301    uint32_t N;
302    uint64_t UncompressedSize = decodeULEB128(P, &N);
303    P += N;
304    uint64_t CompressedSize = decodeULEB128(P, &N);
305    P += N;
306    bool isCompressed = (CompressedSize != 0);
307    SmallString<128> UncompressedNameStrings;
308    StringRef NameStrings;
309    if (isCompressed) {
310      StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
311                                      CompressedSize);
312      if (zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
313                           UncompressedSize) != zlib::StatusOK)
314        return make_error<InstrProfError>(instrprof_error::uncompress_failed);
315      P += CompressedSize;
316      NameStrings = StringRef(UncompressedNameStrings.data(),
317                              UncompressedNameStrings.size());
318    } else {
319      NameStrings =
320          StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
321      P += UncompressedSize;
322    }
323    // Now parse the name strings.
324    SmallVector<StringRef, 0> Names;
325    NameStrings.split(Names, getInstrProfNameSeparator());
326    for (StringRef &Name : Names)
327      Symtab.addFuncName(Name);
328
329    while (P < EndP && *P == 0)
330      P++;
331  }
332  Symtab.finalizeSymtab();
333  return Error::success();
334}
335
336void InstrProfValueSiteRecord::merge(SoftInstrProfErrors &SIPE,
337                                     InstrProfValueSiteRecord &Input,
338                                     uint64_t Weight) {
339  this->sortByTargetValues();
340  Input.sortByTargetValues();
341  auto I = ValueData.begin();
342  auto IE = ValueData.end();
343  for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
344       ++J) {
345    while (I != IE && I->Value < J->Value)
346      ++I;
347    if (I != IE && I->Value == J->Value) {
348      bool Overflowed;
349      I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
350      if (Overflowed)
351        SIPE.addError(instrprof_error::counter_overflow);
352      ++I;
353      continue;
354    }
355    ValueData.insert(I, *J);
356  }
357}
358
359void InstrProfValueSiteRecord::scale(SoftInstrProfErrors &SIPE,
360                                     uint64_t Weight) {
361  for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
362    bool Overflowed;
363    I->Count = SaturatingMultiply(I->Count, Weight, &Overflowed);
364    if (Overflowed)
365      SIPE.addError(instrprof_error::counter_overflow);
366  }
367}
368
369// Merge Value Profile data from Src record to this record for ValueKind.
370// Scale merged value counts by \p Weight.
371void InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
372                                         InstrProfRecord &Src,
373                                         uint64_t Weight) {
374  uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
375  uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
376  if (ThisNumValueSites != OtherNumValueSites) {
377    SIPE.addError(instrprof_error::value_site_count_mismatch);
378    return;
379  }
380  std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
381      getValueSitesForKind(ValueKind);
382  std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
383      Src.getValueSitesForKind(ValueKind);
384  for (uint32_t I = 0; I < ThisNumValueSites; I++)
385    ThisSiteRecords[I].merge(SIPE, OtherSiteRecords[I], Weight);
386}
387
388void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight) {
389  // If the number of counters doesn't match we either have bad data
390  // or a hash collision.
391  if (Counts.size() != Other.Counts.size()) {
392    SIPE.addError(instrprof_error::count_mismatch);
393    return;
394  }
395
396  for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
397    bool Overflowed;
398    Counts[I] =
399        SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
400    if (Overflowed)
401      SIPE.addError(instrprof_error::counter_overflow);
402  }
403
404  for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
405    mergeValueProfData(Kind, Other, Weight);
406}
407
408void InstrProfRecord::scaleValueProfData(uint32_t ValueKind, uint64_t Weight) {
409  uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
410  std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
411      getValueSitesForKind(ValueKind);
412  for (uint32_t I = 0; I < ThisNumValueSites; I++)
413    ThisSiteRecords[I].scale(SIPE, Weight);
414}
415
416void InstrProfRecord::scale(uint64_t Weight) {
417  for (auto &Count : this->Counts) {
418    bool Overflowed;
419    Count = SaturatingMultiply(Count, Weight, &Overflowed);
420    if (Overflowed)
421      SIPE.addError(instrprof_error::counter_overflow);
422  }
423  for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
424    scaleValueProfData(Kind, Weight);
425}
426
427// Map indirect call target name hash to name string.
428uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
429                                     ValueMapType *ValueMap) {
430  if (!ValueMap)
431    return Value;
432  switch (ValueKind) {
433  case IPVK_IndirectCallTarget: {
434    auto Result =
435        std::lower_bound(ValueMap->begin(), ValueMap->end(), Value,
436                         [](const std::pair<uint64_t, uint64_t> &LHS,
437                            uint64_t RHS) { return LHS.first < RHS; });
438   // Raw function pointer collected by value profiler may be from
439   // external functions that are not instrumented. They won't have
440   // mapping data to be used by the deserializer. Force the value to
441   // be 0 in this case.
442    if (Result != ValueMap->end() && Result->first == Value)
443      Value = (uint64_t)Result->second;
444    else
445      Value = 0;
446    break;
447  }
448  }
449  return Value;
450}
451
452void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
453                                   InstrProfValueData *VData, uint32_t N,
454                                   ValueMapType *ValueMap) {
455  for (uint32_t I = 0; I < N; I++) {
456    VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
457  }
458  std::vector<InstrProfValueSiteRecord> &ValueSites =
459      getValueSitesForKind(ValueKind);
460  if (N == 0)
461    ValueSites.emplace_back();
462  else
463    ValueSites.emplace_back(VData, VData + N);
464}
465
466#define INSTR_PROF_COMMON_API_IMPL
467#include "llvm/ProfileData/InstrProfData.inc"
468
469/*!
470 * \brief ValueProfRecordClosure Interface implementation for  InstrProfRecord
471 *  class. These C wrappers are used as adaptors so that C++ code can be
472 *  invoked as callbacks.
473 */
474uint32_t getNumValueKindsInstrProf(const void *Record) {
475  return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
476}
477
478uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
479  return reinterpret_cast<const InstrProfRecord *>(Record)
480      ->getNumValueSites(VKind);
481}
482
483uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
484  return reinterpret_cast<const InstrProfRecord *>(Record)
485      ->getNumValueData(VKind);
486}
487
488uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
489                                         uint32_t S) {
490  return reinterpret_cast<const InstrProfRecord *>(R)
491      ->getNumValueDataForSite(VK, S);
492}
493
494void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
495                              uint32_t K, uint32_t S) {
496  reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(Dst, K, S);
497}
498
499ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
500  ValueProfData *VD =
501      (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
502  memset(VD, 0, TotalSizeInBytes);
503  return VD;
504}
505
506static ValueProfRecordClosure InstrProfRecordClosure = {
507    nullptr,
508    getNumValueKindsInstrProf,
509    getNumValueSitesInstrProf,
510    getNumValueDataInstrProf,
511    getNumValueDataForSiteInstrProf,
512    nullptr,
513    getValueForSiteInstrProf,
514    allocValueProfDataInstrProf};
515
516// Wrapper implementation using the closure mechanism.
517uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
518  InstrProfRecordClosure.Record = &Record;
519  return getValueProfDataSize(&InstrProfRecordClosure);
520}
521
522// Wrapper implementation using the closure mechanism.
523std::unique_ptr<ValueProfData>
524ValueProfData::serializeFrom(const InstrProfRecord &Record) {
525  InstrProfRecordClosure.Record = &Record;
526
527  std::unique_ptr<ValueProfData> VPD(
528      serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
529  return VPD;
530}
531
532void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
533                                    InstrProfRecord::ValueMapType *VMap) {
534  Record.reserveSites(Kind, NumValueSites);
535
536  InstrProfValueData *ValueData = getValueProfRecordValueData(this);
537  for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
538    uint8_t ValueDataCount = this->SiteCountArray[VSite];
539    Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
540    ValueData += ValueDataCount;
541  }
542}
543
544// For writing/serializing,  Old is the host endianness, and  New is
545// byte order intended on disk. For Reading/deserialization, Old
546// is the on-disk source endianness, and New is the host endianness.
547void ValueProfRecord::swapBytes(support::endianness Old,
548                                support::endianness New) {
549  using namespace support;
550  if (Old == New)
551    return;
552
553  if (getHostEndianness() != Old) {
554    sys::swapByteOrder<uint32_t>(NumValueSites);
555    sys::swapByteOrder<uint32_t>(Kind);
556  }
557  uint32_t ND = getValueProfRecordNumValueData(this);
558  InstrProfValueData *VD = getValueProfRecordValueData(this);
559
560  // No need to swap byte array: SiteCountArrray.
561  for (uint32_t I = 0; I < ND; I++) {
562    sys::swapByteOrder<uint64_t>(VD[I].Value);
563    sys::swapByteOrder<uint64_t>(VD[I].Count);
564  }
565  if (getHostEndianness() == Old) {
566    sys::swapByteOrder<uint32_t>(NumValueSites);
567    sys::swapByteOrder<uint32_t>(Kind);
568  }
569}
570
571void ValueProfData::deserializeTo(InstrProfRecord &Record,
572                                  InstrProfRecord::ValueMapType *VMap) {
573  if (NumValueKinds == 0)
574    return;
575
576  ValueProfRecord *VR = getFirstValueProfRecord(this);
577  for (uint32_t K = 0; K < NumValueKinds; K++) {
578    VR->deserializeTo(Record, VMap);
579    VR = getValueProfRecordNext(VR);
580  }
581}
582
583template <class T>
584static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
585  using namespace support;
586  if (Orig == little)
587    return endian::readNext<T, little, unaligned>(D);
588  else
589    return endian::readNext<T, big, unaligned>(D);
590}
591
592static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
593  return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
594                                            ValueProfData());
595}
596
597Error ValueProfData::checkIntegrity() {
598  if (NumValueKinds > IPVK_Last + 1)
599    return make_error<InstrProfError>(instrprof_error::malformed);
600  // Total size needs to be mulltiple of quadword size.
601  if (TotalSize % sizeof(uint64_t))
602    return make_error<InstrProfError>(instrprof_error::malformed);
603
604  ValueProfRecord *VR = getFirstValueProfRecord(this);
605  for (uint32_t K = 0; K < this->NumValueKinds; K++) {
606    if (VR->Kind > IPVK_Last)
607      return make_error<InstrProfError>(instrprof_error::malformed);
608    VR = getValueProfRecordNext(VR);
609    if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
610      return make_error<InstrProfError>(instrprof_error::malformed);
611  }
612  return Error::success();
613}
614
615Expected<std::unique_ptr<ValueProfData>>
616ValueProfData::getValueProfData(const unsigned char *D,
617                                const unsigned char *const BufferEnd,
618                                support::endianness Endianness) {
619  using namespace support;
620  if (D + sizeof(ValueProfData) > BufferEnd)
621    return make_error<InstrProfError>(instrprof_error::truncated);
622
623  const unsigned char *Header = D;
624  uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
625  if (D + TotalSize > BufferEnd)
626    return make_error<InstrProfError>(instrprof_error::too_large);
627
628  std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
629  memcpy(VPD.get(), D, TotalSize);
630  // Byte swap.
631  VPD->swapBytesToHost(Endianness);
632
633  Error E = VPD->checkIntegrity();
634  if (E)
635    return std::move(E);
636
637  return std::move(VPD);
638}
639
640void ValueProfData::swapBytesToHost(support::endianness Endianness) {
641  using namespace support;
642  if (Endianness == getHostEndianness())
643    return;
644
645  sys::swapByteOrder<uint32_t>(TotalSize);
646  sys::swapByteOrder<uint32_t>(NumValueKinds);
647
648  ValueProfRecord *VR = getFirstValueProfRecord(this);
649  for (uint32_t K = 0; K < NumValueKinds; K++) {
650    VR->swapBytes(Endianness, getHostEndianness());
651    VR = getValueProfRecordNext(VR);
652  }
653}
654
655void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
656  using namespace support;
657  if (Endianness == getHostEndianness())
658    return;
659
660  ValueProfRecord *VR = getFirstValueProfRecord(this);
661  for (uint32_t K = 0; K < NumValueKinds; K++) {
662    ValueProfRecord *NVR = getValueProfRecordNext(VR);
663    VR->swapBytes(getHostEndianness(), Endianness);
664    VR = NVR;
665  }
666  sys::swapByteOrder<uint32_t>(TotalSize);
667  sys::swapByteOrder<uint32_t>(NumValueKinds);
668}
669
670void annotateValueSite(Module &M, Instruction &Inst,
671                       const InstrProfRecord &InstrProfR,
672                       InstrProfValueKind ValueKind, uint32_t SiteIdx,
673                       uint32_t MaxMDCount) {
674  uint32_t NV = InstrProfR.getNumValueDataForSite(ValueKind, SiteIdx);
675  if (!NV)
676    return;
677
678  uint64_t Sum = 0;
679  std::unique_ptr<InstrProfValueData[]> VD =
680      InstrProfR.getValueForSite(ValueKind, SiteIdx, &Sum);
681
682  ArrayRef<InstrProfValueData> VDs(VD.get(), NV);
683  annotateValueSite(M, Inst, VDs, Sum, ValueKind, MaxMDCount);
684}
685
686void annotateValueSite(Module &M, Instruction &Inst,
687                       ArrayRef<InstrProfValueData> VDs,
688                       uint64_t Sum, InstrProfValueKind ValueKind,
689                       uint32_t MaxMDCount) {
690  LLVMContext &Ctx = M.getContext();
691  MDBuilder MDHelper(Ctx);
692  SmallVector<Metadata *, 3> Vals;
693  // Tag
694  Vals.push_back(MDHelper.createString("VP"));
695  // Value Kind
696  Vals.push_back(MDHelper.createConstant(
697      ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
698  // Total Count
699  Vals.push_back(
700      MDHelper.createConstant(ConstantInt::get(Type::getInt64Ty(Ctx), Sum)));
701
702  // Value Profile Data
703  uint32_t MDCount = MaxMDCount;
704  for (auto &VD : VDs) {
705    Vals.push_back(MDHelper.createConstant(
706        ConstantInt::get(Type::getInt64Ty(Ctx), VD.Value)));
707    Vals.push_back(MDHelper.createConstant(
708        ConstantInt::get(Type::getInt64Ty(Ctx), VD.Count)));
709    if (--MDCount == 0)
710      break;
711  }
712  Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
713}
714
715bool getValueProfDataFromInst(const Instruction &Inst,
716                              InstrProfValueKind ValueKind,
717                              uint32_t MaxNumValueData,
718                              InstrProfValueData ValueData[],
719                              uint32_t &ActualNumValueData, uint64_t &TotalC) {
720  MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
721  if (!MD)
722    return false;
723
724  unsigned NOps = MD->getNumOperands();
725
726  if (NOps < 5)
727    return false;
728
729  // Operand 0 is a string tag "VP":
730  MDString *Tag = cast<MDString>(MD->getOperand(0));
731  if (!Tag)
732    return false;
733
734  if (!Tag->getString().equals("VP"))
735    return false;
736
737  // Now check kind:
738  ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
739  if (!KindInt)
740    return false;
741  if (KindInt->getZExtValue() != ValueKind)
742    return false;
743
744  // Get total count
745  ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
746  if (!TotalCInt)
747    return false;
748  TotalC = TotalCInt->getZExtValue();
749
750  ActualNumValueData = 0;
751
752  for (unsigned I = 3; I < NOps; I += 2) {
753    if (ActualNumValueData >= MaxNumValueData)
754      break;
755    ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
756    ConstantInt *Count =
757        mdconst::dyn_extract<ConstantInt>(MD->getOperand(I + 1));
758    if (!Value || !Count)
759      return false;
760    ValueData[ActualNumValueData].Value = Value->getZExtValue();
761    ValueData[ActualNumValueData].Count = Count->getZExtValue();
762    ActualNumValueData++;
763  }
764  return true;
765}
766
767MDNode *getPGOFuncNameMetadata(const Function &F) {
768  return F.getMetadata(getPGOFuncNameMetadataName());
769}
770
771void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
772  // Only for internal linkage functions.
773  if (PGOFuncName == F.getName())
774      return;
775  // Don't create duplicated meta-data.
776  if (getPGOFuncNameMetadata(F))
777    return;
778  LLVMContext &C = F.getContext();
779  MDNode *N = MDNode::get(C, MDString::get(C, PGOFuncName));
780  F.setMetadata(getPGOFuncNameMetadataName(), N);
781}
782
783} // end namespace llvm
784