1 //=-- InstrProf.cpp - Instrumented profiling format support -----------------=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for clang's instrumentation based PGO and
13 //===----------------------------------------------------------------------===//
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/Module.h"
21 #include "llvm/Support/Compression.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/LEB128.h"
24 #include "llvm/Support/ManagedStatic.h"
29 class InstrProfErrorCategoryType : public std::error_category {
30 const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
31 std::string message(int IE) const override {
32 instrprof_error E = static_cast<instrprof_error>(IE);
34 case instrprof_error::success:
36 case instrprof_error::eof:
38 case instrprof_error::unrecognized_format:
39 return "Unrecognized instrumentation profile encoding format";
40 case instrprof_error::bad_magic:
41 return "Invalid instrumentation profile data (bad magic)";
42 case instrprof_error::bad_header:
43 return "Invalid instrumentation profile data (file header is corrupt)";
44 case instrprof_error::unsupported_version:
45 return "Unsupported instrumentation profile format version";
46 case instrprof_error::unsupported_hash_type:
47 return "Unsupported instrumentation profile hash type";
48 case instrprof_error::too_large:
49 return "Too much profile data";
50 case instrprof_error::truncated:
51 return "Truncated profile data";
52 case instrprof_error::malformed:
53 return "Malformed instrumentation profile data";
54 case instrprof_error::unknown_function:
55 return "No profile data available for function";
56 case instrprof_error::hash_mismatch:
57 return "Function control flow change detected (hash mismatch)";
58 case instrprof_error::count_mismatch:
59 return "Function basic block count change detected (counter mismatch)";
60 case instrprof_error::counter_overflow:
61 return "Counter overflow";
62 case instrprof_error::value_site_count_mismatch:
63 return "Function value site count change detected (counter mismatch)";
65 llvm_unreachable("A value of instrprof_error has no message.");
70 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
72 const std::error_category &llvm::instrprof_category() {
73 return *ErrorCategory;
78 std::string getPGOFuncName(StringRef RawFuncName,
79 GlobalValue::LinkageTypes Linkage,
81 uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
83 // Function names may be prefixed with a binary '1' to indicate
84 // that the backend should not modify the symbols due to any platform
85 // naming convention. Do not include that '1' in the PGO profile name.
86 if (RawFuncName[0] == '\1')
87 RawFuncName = RawFuncName.substr(1);
89 std::string FuncName = RawFuncName;
90 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
91 // For local symbols, prepend the main file name to distinguish them.
92 // Do not include the full path in the file name since there's no guarantee
93 // that it will stay the same, e.g., if the files are checked out from
94 // version control in different locations.
96 FuncName = FuncName.insert(0, "<unknown>:");
98 FuncName = FuncName.insert(0, FileName.str() + ":");
103 std::string getPGOFuncName(const Function &F, uint64_t Version) {
104 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName(),
108 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
109 if (FileName.empty())
111 // Drop the file name including ':'. See also getPGOFuncName.
112 if (PGOFuncName.startswith(FileName))
113 PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
117 // \p FuncName is the string used as profile lookup key for the function. A
118 // symbol is created to hold the name. Return the legalized symbol name.
119 static std::string getPGOFuncNameVarName(StringRef FuncName,
120 GlobalValue::LinkageTypes Linkage) {
121 std::string VarName = getInstrProfNameVarPrefix();
124 if (!GlobalValue::isLocalLinkage(Linkage))
127 // Now fix up illegal chars in local VarName that may upset the assembler.
128 const char *InvalidChars = "-:<>\"'";
129 size_t found = VarName.find_first_of(InvalidChars);
130 while (found != std::string::npos) {
131 VarName[found] = '_';
132 found = VarName.find_first_of(InvalidChars, found + 1);
137 GlobalVariable *createPGOFuncNameVar(Module &M,
138 GlobalValue::LinkageTypes Linkage,
139 StringRef FuncName) {
141 // We generally want to match the function's linkage, but available_externally
142 // and extern_weak both have the wrong semantics, and anything that doesn't
143 // need to link across compilation units doesn't need to be visible at all.
144 if (Linkage == GlobalValue::ExternalWeakLinkage)
145 Linkage = GlobalValue::LinkOnceAnyLinkage;
146 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
147 Linkage = GlobalValue::LinkOnceODRLinkage;
148 else if (Linkage == GlobalValue::InternalLinkage ||
149 Linkage == GlobalValue::ExternalLinkage)
150 Linkage = GlobalValue::PrivateLinkage;
152 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
154 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
155 getPGOFuncNameVarName(FuncName, Linkage));
157 // Hide the symbol so that we correctly get a copy for each executable.
158 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
159 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
164 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
165 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
168 void InstrProfSymtab::create(const Module &M) {
169 for (const Function &F : M)
170 addFuncName(getPGOFuncName(F));
175 int collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
176 bool doCompression, std::string &Result) {
177 uint8_t Header[16], *P = Header;
178 std::string UncompressedNameStrings =
179 join(NameStrs.begin(), NameStrs.end(), StringRef(" "));
181 unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
184 auto WriteStringToResult = [&](size_t CompressedLen,
185 const std::string &InputStr) {
186 EncLen = encodeULEB128(CompressedLen, P);
188 char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
189 unsigned HeaderLen = P - &Header[0];
190 Result.append(HeaderStr, HeaderLen);
196 return WriteStringToResult(0, UncompressedNameStrings);
198 SmallVector<char, 128> CompressedNameStrings;
199 zlib::Status Success =
200 zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
201 zlib::BestSizeCompression);
203 if (Success != zlib::StatusOK)
206 return WriteStringToResult(
207 CompressedNameStrings.size(),
208 std::string(CompressedNameStrings.data(), CompressedNameStrings.size()));
211 StringRef getPGOFuncNameInitializer(GlobalVariable *NameVar) {
212 auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
214 Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
218 int collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
219 std::string &Result) {
220 std::vector<std::string> NameStrs;
221 for (auto *NameVar : NameVars) {
222 NameStrs.push_back(getPGOFuncNameInitializer(NameVar));
224 return collectPGOFuncNameStrings(NameStrs, zlib::isAvailable(), Result);
227 int readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
228 const uint8_t *P = reinterpret_cast<const uint8_t *>(NameStrings.data());
229 const uint8_t *EndP = reinterpret_cast<const uint8_t *>(NameStrings.data() +
233 uint64_t UncompressedSize = decodeULEB128(P, &N);
235 uint64_t CompressedSize = decodeULEB128(P, &N);
237 bool isCompressed = (CompressedSize != 0);
238 SmallString<128> UncompressedNameStrings;
239 StringRef NameStrings;
241 StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
243 if (zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
244 UncompressedSize) != zlib::StatusOK)
247 NameStrings = StringRef(UncompressedNameStrings.data(),
248 UncompressedNameStrings.size());
251 StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
252 P += UncompressedSize;
254 // Now parse the name strings.
255 SmallVector<StringRef, 0> Names;
256 NameStrings.split(Names, ' ');
257 for (StringRef &Name : Names)
258 Symtab.addFuncName(Name);
260 while (P < EndP && *P == 0)
263 Symtab.finalizeSymtab();
267 instrprof_error InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
269 this->sortByTargetValues();
270 Input.sortByTargetValues();
271 auto I = ValueData.begin();
272 auto IE = ValueData.end();
273 instrprof_error Result = instrprof_error::success;
274 for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
276 while (I != IE && I->Value < J->Value)
278 if (I != IE && I->Value == J->Value) {
280 I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
282 Result = instrprof_error::counter_overflow;
286 ValueData.insert(I, *J);
291 instrprof_error InstrProfValueSiteRecord::scale(uint64_t Weight) {
292 instrprof_error Result = instrprof_error::success;
293 for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
295 I->Count = SaturatingMultiply(I->Count, Weight, &Overflowed);
297 Result = instrprof_error::counter_overflow;
302 // Merge Value Profile data from Src record to this record for ValueKind.
303 // Scale merged value counts by \p Weight.
304 instrprof_error InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
305 InstrProfRecord &Src,
307 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
308 uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
309 if (ThisNumValueSites != OtherNumValueSites)
310 return instrprof_error::value_site_count_mismatch;
311 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
312 getValueSitesForKind(ValueKind);
313 std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
314 Src.getValueSitesForKind(ValueKind);
315 instrprof_error Result = instrprof_error::success;
316 for (uint32_t I = 0; I < ThisNumValueSites; I++)
317 MergeResult(Result, ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight));
321 instrprof_error InstrProfRecord::merge(InstrProfRecord &Other,
323 // If the number of counters doesn't match we either have bad data
324 // or a hash collision.
325 if (Counts.size() != Other.Counts.size())
326 return instrprof_error::count_mismatch;
328 instrprof_error Result = instrprof_error::success;
330 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
333 SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
335 Result = instrprof_error::counter_overflow;
338 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
339 MergeResult(Result, mergeValueProfData(Kind, Other, Weight));
344 instrprof_error InstrProfRecord::scaleValueProfData(uint32_t ValueKind,
346 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
347 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
348 getValueSitesForKind(ValueKind);
349 instrprof_error Result = instrprof_error::success;
350 for (uint32_t I = 0; I < ThisNumValueSites; I++)
351 MergeResult(Result, ThisSiteRecords[I].scale(Weight));
355 instrprof_error InstrProfRecord::scale(uint64_t Weight) {
356 instrprof_error Result = instrprof_error::success;
357 for (auto &Count : this->Counts) {
359 Count = SaturatingMultiply(Count, Weight, &Overflowed);
360 if (Overflowed && Result == instrprof_error::success) {
361 Result = instrprof_error::counter_overflow;
364 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
365 MergeResult(Result, scaleValueProfData(Kind, Weight));
370 // Map indirect call target name hash to name string.
371 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
372 ValueMapType *ValueMap) {
376 case IPVK_IndirectCallTarget: {
378 std::lower_bound(ValueMap->begin(), ValueMap->end(), Value,
379 [](const std::pair<uint64_t, uint64_t> &LHS,
380 uint64_t RHS) { return LHS.first < RHS; });
381 if (Result != ValueMap->end())
382 Value = (uint64_t)Result->second;
389 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
390 InstrProfValueData *VData, uint32_t N,
391 ValueMapType *ValueMap) {
392 for (uint32_t I = 0; I < N; I++) {
393 VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
395 std::vector<InstrProfValueSiteRecord> &ValueSites =
396 getValueSitesForKind(ValueKind);
398 ValueSites.push_back(InstrProfValueSiteRecord());
400 ValueSites.emplace_back(VData, VData + N);
403 #define INSTR_PROF_COMMON_API_IMPL
404 #include "llvm/ProfileData/InstrProfData.inc"
407 * \brief ValueProfRecordClosure Interface implementation for InstrProfRecord
408 * class. These C wrappers are used as adaptors so that C++ code can be
409 * invoked as callbacks.
411 uint32_t getNumValueKindsInstrProf(const void *Record) {
412 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
415 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
416 return reinterpret_cast<const InstrProfRecord *>(Record)
417 ->getNumValueSites(VKind);
420 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
421 return reinterpret_cast<const InstrProfRecord *>(Record)
422 ->getNumValueData(VKind);
425 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
427 return reinterpret_cast<const InstrProfRecord *>(R)
428 ->getNumValueDataForSite(VK, S);
431 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
432 uint32_t K, uint32_t S,
433 uint64_t (*Mapper)(uint32_t, uint64_t)) {
434 return reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(
438 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
440 (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
441 memset(VD, 0, TotalSizeInBytes);
445 static ValueProfRecordClosure InstrProfRecordClosure = {
447 getNumValueKindsInstrProf,
448 getNumValueSitesInstrProf,
449 getNumValueDataInstrProf,
450 getNumValueDataForSiteInstrProf,
452 getValueForSiteInstrProf,
453 allocValueProfDataInstrProf};
455 // Wrapper implementation using the closure mechanism.
456 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
457 InstrProfRecordClosure.Record = &Record;
458 return getValueProfDataSize(&InstrProfRecordClosure);
461 // Wrapper implementation using the closure mechanism.
462 std::unique_ptr<ValueProfData>
463 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
464 InstrProfRecordClosure.Record = &Record;
466 std::unique_ptr<ValueProfData> VPD(
467 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
471 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
472 InstrProfRecord::ValueMapType *VMap) {
473 Record.reserveSites(Kind, NumValueSites);
475 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
476 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
477 uint8_t ValueDataCount = this->SiteCountArray[VSite];
478 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
479 ValueData += ValueDataCount;
483 // For writing/serializing, Old is the host endianness, and New is
484 // byte order intended on disk. For Reading/deserialization, Old
485 // is the on-disk source endianness, and New is the host endianness.
486 void ValueProfRecord::swapBytes(support::endianness Old,
487 support::endianness New) {
488 using namespace support;
492 if (getHostEndianness() != Old) {
493 sys::swapByteOrder<uint32_t>(NumValueSites);
494 sys::swapByteOrder<uint32_t>(Kind);
496 uint32_t ND = getValueProfRecordNumValueData(this);
497 InstrProfValueData *VD = getValueProfRecordValueData(this);
499 // No need to swap byte array: SiteCountArrray.
500 for (uint32_t I = 0; I < ND; I++) {
501 sys::swapByteOrder<uint64_t>(VD[I].Value);
502 sys::swapByteOrder<uint64_t>(VD[I].Count);
504 if (getHostEndianness() == Old) {
505 sys::swapByteOrder<uint32_t>(NumValueSites);
506 sys::swapByteOrder<uint32_t>(Kind);
510 void ValueProfData::deserializeTo(InstrProfRecord &Record,
511 InstrProfRecord::ValueMapType *VMap) {
512 if (NumValueKinds == 0)
515 ValueProfRecord *VR = getFirstValueProfRecord(this);
516 for (uint32_t K = 0; K < NumValueKinds; K++) {
517 VR->deserializeTo(Record, VMap);
518 VR = getValueProfRecordNext(VR);
523 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
524 using namespace support;
526 return endian::readNext<T, little, unaligned>(D);
528 return endian::readNext<T, big, unaligned>(D);
531 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
532 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
536 instrprof_error ValueProfData::checkIntegrity() {
537 if (NumValueKinds > IPVK_Last + 1)
538 return instrprof_error::malformed;
539 // Total size needs to be mulltiple of quadword size.
540 if (TotalSize % sizeof(uint64_t))
541 return instrprof_error::malformed;
543 ValueProfRecord *VR = getFirstValueProfRecord(this);
544 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
545 if (VR->Kind > IPVK_Last)
546 return instrprof_error::malformed;
547 VR = getValueProfRecordNext(VR);
548 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
549 return instrprof_error::malformed;
551 return instrprof_error::success;
554 ErrorOr<std::unique_ptr<ValueProfData>>
555 ValueProfData::getValueProfData(const unsigned char *D,
556 const unsigned char *const BufferEnd,
557 support::endianness Endianness) {
558 using namespace support;
559 if (D + sizeof(ValueProfData) > BufferEnd)
560 return instrprof_error::truncated;
562 const unsigned char *Header = D;
563 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
564 if (D + TotalSize > BufferEnd)
565 return instrprof_error::too_large;
567 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
568 memcpy(VPD.get(), D, TotalSize);
570 VPD->swapBytesToHost(Endianness);
572 instrprof_error EC = VPD->checkIntegrity();
573 if (EC != instrprof_error::success)
576 return std::move(VPD);
579 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
580 using namespace support;
581 if (Endianness == getHostEndianness())
584 sys::swapByteOrder<uint32_t>(TotalSize);
585 sys::swapByteOrder<uint32_t>(NumValueKinds);
587 ValueProfRecord *VR = getFirstValueProfRecord(this);
588 for (uint32_t K = 0; K < NumValueKinds; K++) {
589 VR->swapBytes(Endianness, getHostEndianness());
590 VR = getValueProfRecordNext(VR);
594 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
595 using namespace support;
596 if (Endianness == getHostEndianness())
599 ValueProfRecord *VR = getFirstValueProfRecord(this);
600 for (uint32_t K = 0; K < NumValueKinds; K++) {
601 ValueProfRecord *NVR = getValueProfRecordNext(VR);
602 VR->swapBytes(getHostEndianness(), Endianness);
605 sys::swapByteOrder<uint32_t>(TotalSize);
606 sys::swapByteOrder<uint32_t>(NumValueKinds);
609 // The argument to this method is a vector of cutoff percentages and the return
610 // value is a vector of (Cutoff, MinBlockCount, NumBlocks) triplets.
611 void ProfileSummary::computeDetailedSummary() {
612 if (DetailedSummaryCutoffs.empty())
614 auto Iter = CountFrequencies.begin();
615 auto End = CountFrequencies.end();
616 std::sort(DetailedSummaryCutoffs.begin(), DetailedSummaryCutoffs.end());
618 uint32_t BlocksSeen = 0;
619 uint64_t CurrSum = 0, Count;
621 for (uint32_t Cutoff : DetailedSummaryCutoffs) {
622 assert(Cutoff <= 999999);
623 APInt Temp(128, TotalCount);
624 APInt N(128, Cutoff);
625 APInt D(128, ProfileSummary::Scale);
628 uint64_t DesiredCount = Temp.getZExtValue();
629 assert(DesiredCount <= TotalCount);
630 while (CurrSum < DesiredCount && Iter != End) {
632 uint32_t Freq = Iter->second;
633 CurrSum += (Count * Freq);
637 assert(CurrSum >= DesiredCount);
638 ProfileSummaryEntry PSE = {Cutoff, Count, BlocksSeen};
639 DetailedSummary.push_back(PSE);