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 int collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
169 bool doCompression, std::string &Result) {
170 uint8_t Header[16], *P = Header;
171 std::string UncompressedNameStrings =
172 join(NameStrs.begin(), NameStrs.end(), StringRef(" "));
174 unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
177 auto WriteStringToResult = [&](size_t CompressedLen,
178 const std::string &InputStr) {
179 EncLen = encodeULEB128(CompressedLen, P);
181 char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
182 unsigned HeaderLen = P - &Header[0];
183 Result.append(HeaderStr, HeaderLen);
189 return WriteStringToResult(0, UncompressedNameStrings);
191 SmallVector<char, 128> CompressedNameStrings;
192 zlib::Status Success =
193 zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
194 zlib::BestSizeCompression);
196 if (Success != zlib::StatusOK)
199 return WriteStringToResult(
200 CompressedNameStrings.size(),
201 std::string(CompressedNameStrings.data(), CompressedNameStrings.size()));
204 StringRef getPGOFuncNameInitializer(GlobalVariable *NameVar) {
205 auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
207 Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
211 int collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
212 std::string &Result) {
213 std::vector<std::string> NameStrs;
214 for (auto *NameVar : NameVars) {
215 NameStrs.push_back(getPGOFuncNameInitializer(NameVar));
217 return collectPGOFuncNameStrings(NameStrs, zlib::isAvailable(), Result);
220 int readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
221 const uint8_t *P = reinterpret_cast<const uint8_t *>(NameStrings.data());
222 const uint8_t *EndP = reinterpret_cast<const uint8_t *>(NameStrings.data() +
226 uint64_t UncompressedSize = decodeULEB128(P, &N);
228 uint64_t CompressedSize = decodeULEB128(P, &N);
230 bool isCompressed = (CompressedSize != 0);
231 SmallString<128> UncompressedNameStrings;
232 StringRef NameStrings;
234 StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
236 if (zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
237 UncompressedSize) != zlib::StatusOK)
240 NameStrings = StringRef(UncompressedNameStrings.data(),
241 UncompressedNameStrings.size());
244 StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
245 P += UncompressedSize;
247 // Now parse the name strings.
248 SmallVector<StringRef, 0> Names;
249 NameStrings.split(Names, ' ');
250 for (StringRef &Name : Names)
251 Symtab.addFuncName(Name);
253 while (P < EndP && *P == 0)
256 Symtab.finalizeSymtab();
260 instrprof_error InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
262 this->sortByTargetValues();
263 Input.sortByTargetValues();
264 auto I = ValueData.begin();
265 auto IE = ValueData.end();
266 instrprof_error Result = instrprof_error::success;
267 for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
269 while (I != IE && I->Value < J->Value)
271 if (I != IE && I->Value == J->Value) {
273 I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
275 Result = instrprof_error::counter_overflow;
279 ValueData.insert(I, *J);
284 instrprof_error InstrProfValueSiteRecord::scale(uint64_t Weight) {
285 instrprof_error Result = instrprof_error::success;
286 for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
288 I->Count = SaturatingMultiply(I->Count, Weight, &Overflowed);
290 Result = instrprof_error::counter_overflow;
295 // Merge Value Profile data from Src record to this record for ValueKind.
296 // Scale merged value counts by \p Weight.
297 instrprof_error InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
298 InstrProfRecord &Src,
300 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
301 uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
302 if (ThisNumValueSites != OtherNumValueSites)
303 return instrprof_error::value_site_count_mismatch;
304 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
305 getValueSitesForKind(ValueKind);
306 std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
307 Src.getValueSitesForKind(ValueKind);
308 instrprof_error Result = instrprof_error::success;
309 for (uint32_t I = 0; I < ThisNumValueSites; I++)
310 MergeResult(Result, ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight));
314 instrprof_error InstrProfRecord::merge(InstrProfRecord &Other,
316 // If the number of counters doesn't match we either have bad data
317 // or a hash collision.
318 if (Counts.size() != Other.Counts.size())
319 return instrprof_error::count_mismatch;
321 instrprof_error Result = instrprof_error::success;
323 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
326 SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
328 Result = instrprof_error::counter_overflow;
331 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
332 MergeResult(Result, mergeValueProfData(Kind, Other, Weight));
337 instrprof_error InstrProfRecord::scaleValueProfData(uint32_t ValueKind,
339 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
340 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
341 getValueSitesForKind(ValueKind);
342 instrprof_error Result = instrprof_error::success;
343 for (uint32_t I = 0; I < ThisNumValueSites; I++)
344 MergeResult(Result, ThisSiteRecords[I].scale(Weight));
348 instrprof_error InstrProfRecord::scale(uint64_t Weight) {
349 instrprof_error Result = instrprof_error::success;
350 for (auto &Count : this->Counts) {
352 Count = SaturatingMultiply(Count, Weight, &Overflowed);
353 if (Overflowed && Result == instrprof_error::success) {
354 Result = instrprof_error::counter_overflow;
357 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
358 MergeResult(Result, scaleValueProfData(Kind, Weight));
363 // Map indirect call target name hash to name string.
364 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
365 ValueMapType *ValueMap) {
369 case IPVK_IndirectCallTarget: {
371 std::lower_bound(ValueMap->begin(), ValueMap->end(), Value,
372 [](const std::pair<uint64_t, uint64_t> &LHS,
373 uint64_t RHS) { return LHS.first < RHS; });
374 if (Result != ValueMap->end())
375 Value = (uint64_t)Result->second;
382 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
383 InstrProfValueData *VData, uint32_t N,
384 ValueMapType *ValueMap) {
385 for (uint32_t I = 0; I < N; I++) {
386 VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
388 std::vector<InstrProfValueSiteRecord> &ValueSites =
389 getValueSitesForKind(ValueKind);
391 ValueSites.push_back(InstrProfValueSiteRecord());
393 ValueSites.emplace_back(VData, VData + N);
396 #define INSTR_PROF_COMMON_API_IMPL
397 #include "llvm/ProfileData/InstrProfData.inc"
400 * \brief ValueProfRecordClosure Interface implementation for InstrProfRecord
401 * class. These C wrappers are used as adaptors so that C++ code can be
402 * invoked as callbacks.
404 uint32_t getNumValueKindsInstrProf(const void *Record) {
405 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
408 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
409 return reinterpret_cast<const InstrProfRecord *>(Record)
410 ->getNumValueSites(VKind);
413 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
414 return reinterpret_cast<const InstrProfRecord *>(Record)
415 ->getNumValueData(VKind);
418 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
420 return reinterpret_cast<const InstrProfRecord *>(R)
421 ->getNumValueDataForSite(VK, S);
424 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
425 uint32_t K, uint32_t S,
426 uint64_t (*Mapper)(uint32_t, uint64_t)) {
427 return reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(
431 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
433 (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
434 memset(VD, 0, TotalSizeInBytes);
438 static ValueProfRecordClosure InstrProfRecordClosure = {
440 getNumValueKindsInstrProf,
441 getNumValueSitesInstrProf,
442 getNumValueDataInstrProf,
443 getNumValueDataForSiteInstrProf,
445 getValueForSiteInstrProf,
446 allocValueProfDataInstrProf};
448 // Wrapper implementation using the closure mechanism.
449 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
450 InstrProfRecordClosure.Record = &Record;
451 return getValueProfDataSize(&InstrProfRecordClosure);
454 // Wrapper implementation using the closure mechanism.
455 std::unique_ptr<ValueProfData>
456 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
457 InstrProfRecordClosure.Record = &Record;
459 std::unique_ptr<ValueProfData> VPD(
460 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
464 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
465 InstrProfRecord::ValueMapType *VMap) {
466 Record.reserveSites(Kind, NumValueSites);
468 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
469 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
470 uint8_t ValueDataCount = this->SiteCountArray[VSite];
471 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
472 ValueData += ValueDataCount;
476 // For writing/serializing, Old is the host endianness, and New is
477 // byte order intended on disk. For Reading/deserialization, Old
478 // is the on-disk source endianness, and New is the host endianness.
479 void ValueProfRecord::swapBytes(support::endianness Old,
480 support::endianness New) {
481 using namespace support;
485 if (getHostEndianness() != Old) {
486 sys::swapByteOrder<uint32_t>(NumValueSites);
487 sys::swapByteOrder<uint32_t>(Kind);
489 uint32_t ND = getValueProfRecordNumValueData(this);
490 InstrProfValueData *VD = getValueProfRecordValueData(this);
492 // No need to swap byte array: SiteCountArrray.
493 for (uint32_t I = 0; I < ND; I++) {
494 sys::swapByteOrder<uint64_t>(VD[I].Value);
495 sys::swapByteOrder<uint64_t>(VD[I].Count);
497 if (getHostEndianness() == Old) {
498 sys::swapByteOrder<uint32_t>(NumValueSites);
499 sys::swapByteOrder<uint32_t>(Kind);
503 void ValueProfData::deserializeTo(InstrProfRecord &Record,
504 InstrProfRecord::ValueMapType *VMap) {
505 if (NumValueKinds == 0)
508 ValueProfRecord *VR = getFirstValueProfRecord(this);
509 for (uint32_t K = 0; K < NumValueKinds; K++) {
510 VR->deserializeTo(Record, VMap);
511 VR = getValueProfRecordNext(VR);
516 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
517 using namespace support;
519 return endian::readNext<T, little, unaligned>(D);
521 return endian::readNext<T, big, unaligned>(D);
524 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
525 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
529 instrprof_error ValueProfData::checkIntegrity() {
530 if (NumValueKinds > IPVK_Last + 1)
531 return instrprof_error::malformed;
532 // Total size needs to be mulltiple of quadword size.
533 if (TotalSize % sizeof(uint64_t))
534 return instrprof_error::malformed;
536 ValueProfRecord *VR = getFirstValueProfRecord(this);
537 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
538 if (VR->Kind > IPVK_Last)
539 return instrprof_error::malformed;
540 VR = getValueProfRecordNext(VR);
541 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
542 return instrprof_error::malformed;
544 return instrprof_error::success;
547 ErrorOr<std::unique_ptr<ValueProfData>>
548 ValueProfData::getValueProfData(const unsigned char *D,
549 const unsigned char *const BufferEnd,
550 support::endianness Endianness) {
551 using namespace support;
552 if (D + sizeof(ValueProfData) > BufferEnd)
553 return instrprof_error::truncated;
555 const unsigned char *Header = D;
556 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
557 if (D + TotalSize > BufferEnd)
558 return instrprof_error::too_large;
560 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
561 memcpy(VPD.get(), D, TotalSize);
563 VPD->swapBytesToHost(Endianness);
565 instrprof_error EC = VPD->checkIntegrity();
566 if (EC != instrprof_error::success)
569 return std::move(VPD);
572 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
573 using namespace support;
574 if (Endianness == getHostEndianness())
577 sys::swapByteOrder<uint32_t>(TotalSize);
578 sys::swapByteOrder<uint32_t>(NumValueKinds);
580 ValueProfRecord *VR = getFirstValueProfRecord(this);
581 for (uint32_t K = 0; K < NumValueKinds; K++) {
582 VR->swapBytes(Endianness, getHostEndianness());
583 VR = getValueProfRecordNext(VR);
587 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
588 using namespace support;
589 if (Endianness == getHostEndianness())
592 ValueProfRecord *VR = getFirstValueProfRecord(this);
593 for (uint32_t K = 0; K < NumValueKinds; K++) {
594 ValueProfRecord *NVR = getValueProfRecordNext(VR);
595 VR->swapBytes(getHostEndianness(), Endianness);
598 sys::swapByteOrder<uint32_t>(TotalSize);
599 sys::swapByteOrder<uint32_t>(NumValueKinds);