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/IR/Constants.h"
17 #include "llvm/IR/Function.h"
18 #include "llvm/IR/GlobalVariable.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/Support/Compression.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/LEB128.h"
23 #include "llvm/Support/ManagedStatic.h"
28 class InstrProfErrorCategoryType : public std::error_category {
29 const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
30 std::string message(int IE) const override {
31 instrprof_error E = static_cast<instrprof_error>(IE);
33 case instrprof_error::success:
35 case instrprof_error::eof:
37 case instrprof_error::unrecognized_format:
38 return "Unrecognized instrumentation profile encoding format";
39 case instrprof_error::bad_magic:
40 return "Invalid instrumentation profile data (bad magic)";
41 case instrprof_error::bad_header:
42 return "Invalid instrumentation profile data (file header is corrupt)";
43 case instrprof_error::unsupported_version:
44 return "Unsupported instrumentation profile format version";
45 case instrprof_error::unsupported_hash_type:
46 return "Unsupported instrumentation profile hash type";
47 case instrprof_error::too_large:
48 return "Too much profile data";
49 case instrprof_error::truncated:
50 return "Truncated profile data";
51 case instrprof_error::malformed:
52 return "Malformed instrumentation profile data";
53 case instrprof_error::unknown_function:
54 return "No profile data available for function";
55 case instrprof_error::hash_mismatch:
56 return "Function control flow change detected (hash mismatch)";
57 case instrprof_error::count_mismatch:
58 return "Function basic block count change detected (counter mismatch)";
59 case instrprof_error::counter_overflow:
60 return "Counter overflow";
61 case instrprof_error::value_site_count_mismatch:
62 return "Function value site count change detected (counter mismatch)";
64 llvm_unreachable("A value of instrprof_error has no message.");
69 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
71 const std::error_category &llvm::instrprof_category() {
72 return *ErrorCategory;
77 std::string getPGOFuncName(StringRef RawFuncName,
78 GlobalValue::LinkageTypes Linkage,
80 uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
82 // Function names may be prefixed with a binary '1' to indicate
83 // that the backend should not modify the symbols due to any platform
84 // naming convention. Do not include that '1' in the PGO profile name.
85 if (RawFuncName[0] == '\1')
86 RawFuncName = RawFuncName.substr(1);
88 std::string FuncName = RawFuncName;
89 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
90 // For local symbols, prepend the main file name to distinguish them.
91 // Do not include the full path in the file name since there's no guarantee
92 // that it will stay the same, e.g., if the files are checked out from
93 // version control in different locations.
95 FuncName = FuncName.insert(0, "<unknown>:");
97 FuncName = FuncName.insert(0, FileName.str() + ":");
102 std::string getPGOFuncName(const Function &F, uint64_t Version) {
103 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName(),
107 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
108 if (FileName.empty())
110 // Drop the file name including ':'. See also getPGOFuncName.
111 if (PGOFuncName.startswith(FileName))
112 PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
116 // \p FuncName is the string used as profile lookup key for the function. A
117 // symbol is created to hold the name. Return the legalized symbol name.
118 static std::string getPGOFuncNameVarName(StringRef FuncName,
119 GlobalValue::LinkageTypes Linkage) {
120 std::string VarName = getInstrProfNameVarPrefix();
123 if (!GlobalValue::isLocalLinkage(Linkage))
126 // Now fix up illegal chars in local VarName that may upset the assembler.
127 const char *InvalidChars = "-:<>\"'";
128 size_t found = VarName.find_first_of(InvalidChars);
129 while (found != std::string::npos) {
130 VarName[found] = '_';
131 found = VarName.find_first_of(InvalidChars, found + 1);
136 GlobalVariable *createPGOFuncNameVar(Module &M,
137 GlobalValue::LinkageTypes Linkage,
138 StringRef FuncName) {
140 // We generally want to match the function's linkage, but available_externally
141 // and extern_weak both have the wrong semantics, and anything that doesn't
142 // need to link across compilation units doesn't need to be visible at all.
143 if (Linkage == GlobalValue::ExternalWeakLinkage)
144 Linkage = GlobalValue::LinkOnceAnyLinkage;
145 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
146 Linkage = GlobalValue::LinkOnceODRLinkage;
147 else if (Linkage == GlobalValue::InternalLinkage ||
148 Linkage == GlobalValue::ExternalLinkage)
149 Linkage = GlobalValue::PrivateLinkage;
151 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
153 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
154 getPGOFuncNameVarName(FuncName, Linkage));
156 // Hide the symbol so that we correctly get a copy for each executable.
157 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
158 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
163 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
164 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
167 int collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
168 bool doCompression, std::string &Result) {
169 uint8_t Header[16], *P = Header;
170 std::string UncompressedNameStrings;
172 for (auto NameStr : NameStrs) {
173 UncompressedNameStrings += NameStr;
174 UncompressedNameStrings.append(" ");
176 unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
178 if (!doCompression) {
179 EncLen = encodeULEB128(0, P);
181 Result.append(reinterpret_cast<char *>(&Header[0]), P - &Header[0]);
182 Result += UncompressedNameStrings;
185 SmallVector<char, 128> CompressedNameStrings;
186 zlib::Status Success =
187 zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
188 zlib::BestSizeCompression);
189 assert(Success == zlib::StatusOK);
190 if (Success != zlib::StatusOK)
192 EncLen = encodeULEB128(CompressedNameStrings.size(), P);
194 Result.append(reinterpret_cast<char *>(&Header[0]), P - &Header[0]);
196 std::string(CompressedNameStrings.data(), CompressedNameStrings.size());
200 int collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
201 std::string &Result) {
202 std::vector<std::string> NameStrs;
203 for (auto *NameVar : NameVars) {
204 auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
206 Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
207 NameStrs.push_back(NameStr.str());
209 return collectPGOFuncNameStrings(NameStrs, zlib::isAvailable(), Result);
212 int readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
213 const uint8_t *P = reinterpret_cast<const uint8_t *>(NameStrings.data());
214 const uint8_t *EndP = reinterpret_cast<const uint8_t *>(NameStrings.data() +
218 uint64_t UncompressedSize = decodeULEB128(P, &N);
220 uint64_t CompressedSize = decodeULEB128(P, &N);
222 bool isCompressed = (CompressedSize != 0);
223 SmallString<128> UncompressedNameStrings;
224 StringRef NameStrings;
226 StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
228 if (zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
229 UncompressedSize) != zlib::StatusOK)
232 NameStrings = StringRef(UncompressedNameStrings.data(),
233 UncompressedNameStrings.size());
236 StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
237 P += UncompressedSize;
239 // Now parse the name strings.
240 size_t NameStart = 0;
243 size_t NameStop = NameStrings.find(' ', NameStart);
244 if (NameStop == StringRef::npos)
246 if (NameStop == NameStrings.size() - 1)
248 StringRef Name = NameStrings.substr(NameStart, NameStop - NameStart);
249 Symtab.addFuncName(Name);
252 NameStart = NameStop + 1;
255 while (P < EndP && *P == 0)
258 Symtab.finalizeSymtab();
263 InstrProfValueSiteRecord::mergeValueData(InstrProfValueSiteRecord &Input,
265 this->sortByTargetValues();
266 Input.sortByTargetValues();
267 auto I = ValueData.begin();
268 auto IE = ValueData.end();
269 instrprof_error Result = instrprof_error::success;
270 for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
272 while (I != IE && I->Value < J->Value)
274 if (I != IE && I->Value == J->Value) {
275 uint64_t JCount = J->Count;
278 JCount = SaturatingMultiply(JCount, Weight, &Overflowed);
280 Result = instrprof_error::counter_overflow;
282 I->Count = SaturatingAdd(I->Count, JCount, &Overflowed);
284 Result = instrprof_error::counter_overflow;
288 ValueData.insert(I, *J);
293 // Merge Value Profile data from Src record to this record for ValueKind.
294 // Scale merged value counts by \p Weight.
295 instrprof_error InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
296 InstrProfRecord &Src,
298 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
299 uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
300 if (ThisNumValueSites != OtherNumValueSites)
301 return instrprof_error::value_site_count_mismatch;
302 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
303 getValueSitesForKind(ValueKind);
304 std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
305 Src.getValueSitesForKind(ValueKind);
306 instrprof_error Result = instrprof_error::success;
307 for (uint32_t I = 0; I < ThisNumValueSites; I++)
309 ThisSiteRecords[I].mergeValueData(OtherSiteRecords[I], Weight));
313 instrprof_error InstrProfRecord::merge(InstrProfRecord &Other,
315 // If the number of counters doesn't match we either have bad data
316 // or a hash collision.
317 if (Counts.size() != Other.Counts.size())
318 return instrprof_error::count_mismatch;
320 instrprof_error Result = instrprof_error::success;
322 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
324 uint64_t OtherCount = Other.Counts[I];
326 OtherCount = SaturatingMultiply(OtherCount, Weight, &Overflowed);
328 Result = instrprof_error::counter_overflow;
330 Counts[I] = SaturatingAdd(Counts[I], OtherCount, &Overflowed);
332 Result = instrprof_error::counter_overflow;
335 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
336 MergeResult(Result, mergeValueProfData(Kind, Other, Weight));
341 // Map indirect call target name hash to name string.
342 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
343 ValueMapType *ValueMap) {
347 case IPVK_IndirectCallTarget: {
349 std::lower_bound(ValueMap->begin(), ValueMap->end(), Value,
350 [](const std::pair<uint64_t, uint64_t> &LHS,
351 uint64_t RHS) { return LHS.first < RHS; });
352 if (Result != ValueMap->end())
353 Value = (uint64_t)Result->second;
360 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
361 InstrProfValueData *VData, uint32_t N,
362 ValueMapType *ValueMap) {
363 for (uint32_t I = 0; I < N; I++) {
364 VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
366 std::vector<InstrProfValueSiteRecord> &ValueSites =
367 getValueSitesForKind(ValueKind);
369 ValueSites.push_back(InstrProfValueSiteRecord());
371 ValueSites.emplace_back(VData, VData + N);
374 #define INSTR_PROF_COMMON_API_IMPL
375 #include "llvm/ProfileData/InstrProfData.inc"
378 * \brief ValueProfRecordClosure Interface implementation for InstrProfRecord
379 * class. These C wrappers are used as adaptors so that C++ code can be
380 * invoked as callbacks.
382 uint32_t getNumValueKindsInstrProf(const void *Record) {
383 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
386 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
387 return reinterpret_cast<const InstrProfRecord *>(Record)
388 ->getNumValueSites(VKind);
391 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
392 return reinterpret_cast<const InstrProfRecord *>(Record)
393 ->getNumValueData(VKind);
396 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
398 return reinterpret_cast<const InstrProfRecord *>(R)
399 ->getNumValueDataForSite(VK, S);
402 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
403 uint32_t K, uint32_t S,
404 uint64_t (*Mapper)(uint32_t, uint64_t)) {
405 return reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(
409 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
411 (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
412 memset(VD, 0, TotalSizeInBytes);
416 static ValueProfRecordClosure InstrProfRecordClosure = {
418 getNumValueKindsInstrProf,
419 getNumValueSitesInstrProf,
420 getNumValueDataInstrProf,
421 getNumValueDataForSiteInstrProf,
423 getValueForSiteInstrProf,
424 allocValueProfDataInstrProf};
426 // Wrapper implementation using the closure mechanism.
427 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
428 InstrProfRecordClosure.Record = &Record;
429 return getValueProfDataSize(&InstrProfRecordClosure);
432 // Wrapper implementation using the closure mechanism.
433 std::unique_ptr<ValueProfData>
434 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
435 InstrProfRecordClosure.Record = &Record;
437 std::unique_ptr<ValueProfData> VPD(
438 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
442 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
443 InstrProfRecord::ValueMapType *VMap) {
444 Record.reserveSites(Kind, NumValueSites);
446 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
447 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
448 uint8_t ValueDataCount = this->SiteCountArray[VSite];
449 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
450 ValueData += ValueDataCount;
454 // For writing/serializing, Old is the host endianness, and New is
455 // byte order intended on disk. For Reading/deserialization, Old
456 // is the on-disk source endianness, and New is the host endianness.
457 void ValueProfRecord::swapBytes(support::endianness Old,
458 support::endianness New) {
459 using namespace support;
463 if (getHostEndianness() != Old) {
464 sys::swapByteOrder<uint32_t>(NumValueSites);
465 sys::swapByteOrder<uint32_t>(Kind);
467 uint32_t ND = getValueProfRecordNumValueData(this);
468 InstrProfValueData *VD = getValueProfRecordValueData(this);
470 // No need to swap byte array: SiteCountArrray.
471 for (uint32_t I = 0; I < ND; I++) {
472 sys::swapByteOrder<uint64_t>(VD[I].Value);
473 sys::swapByteOrder<uint64_t>(VD[I].Count);
475 if (getHostEndianness() == Old) {
476 sys::swapByteOrder<uint32_t>(NumValueSites);
477 sys::swapByteOrder<uint32_t>(Kind);
481 void ValueProfData::deserializeTo(InstrProfRecord &Record,
482 InstrProfRecord::ValueMapType *VMap) {
483 if (NumValueKinds == 0)
486 ValueProfRecord *VR = getFirstValueProfRecord(this);
487 for (uint32_t K = 0; K < NumValueKinds; K++) {
488 VR->deserializeTo(Record, VMap);
489 VR = getValueProfRecordNext(VR);
494 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
495 using namespace support;
497 return endian::readNext<T, little, unaligned>(D);
499 return endian::readNext<T, big, unaligned>(D);
502 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
503 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
507 instrprof_error ValueProfData::checkIntegrity() {
508 if (NumValueKinds > IPVK_Last + 1)
509 return instrprof_error::malformed;
510 // Total size needs to be mulltiple of quadword size.
511 if (TotalSize % sizeof(uint64_t))
512 return instrprof_error::malformed;
514 ValueProfRecord *VR = getFirstValueProfRecord(this);
515 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
516 if (VR->Kind > IPVK_Last)
517 return instrprof_error::malformed;
518 VR = getValueProfRecordNext(VR);
519 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
520 return instrprof_error::malformed;
522 return instrprof_error::success;
525 ErrorOr<std::unique_ptr<ValueProfData>>
526 ValueProfData::getValueProfData(const unsigned char *D,
527 const unsigned char *const BufferEnd,
528 support::endianness Endianness) {
529 using namespace support;
530 if (D + sizeof(ValueProfData) > BufferEnd)
531 return instrprof_error::truncated;
533 const unsigned char *Header = D;
534 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
535 if (D + TotalSize > BufferEnd)
536 return instrprof_error::too_large;
538 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
539 memcpy(VPD.get(), D, TotalSize);
541 VPD->swapBytesToHost(Endianness);
543 instrprof_error EC = VPD->checkIntegrity();
544 if (EC != instrprof_error::success)
547 return std::move(VPD);
550 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
551 using namespace support;
552 if (Endianness == getHostEndianness())
555 sys::swapByteOrder<uint32_t>(TotalSize);
556 sys::swapByteOrder<uint32_t>(NumValueKinds);
558 ValueProfRecord *VR = getFirstValueProfRecord(this);
559 for (uint32_t K = 0; K < NumValueKinds; K++) {
560 VR->swapBytes(Endianness, getHostEndianness());
561 VR = getValueProfRecordNext(VR);
565 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
566 using namespace support;
567 if (Endianness == getHostEndianness())
570 ValueProfRecord *VR = getFirstValueProfRecord(this);
571 for (uint32_t K = 0; K < NumValueKinds; K++) {
572 ValueProfRecord *NVR = getValueProfRecordNext(VR);
573 VR->swapBytes(getHostEndianness(), Endianness);
576 sys::swapByteOrder<uint32_t>(TotalSize);
577 sys::swapByteOrder<uint32_t>(NumValueKinds);