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/IR/Constants.h"
16 #include "llvm/IR/Function.h"
17 #include "llvm/IR/Module.h"
18 #include "llvm/IR/GlobalVariable.h"
19 #include "llvm/ProfileData/InstrProf.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/ManagedStatic.h"
26 class InstrProfErrorCategoryType : public std::error_category {
27 const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
28 std::string message(int IE) const override {
29 instrprof_error E = static_cast<instrprof_error>(IE);
31 case instrprof_error::success:
33 case instrprof_error::eof:
35 case instrprof_error::unrecognized_format:
36 return "Unrecognized instrumentation profile encoding format";
37 case instrprof_error::bad_magic:
38 return "Invalid instrumentation profile data (bad magic)";
39 case instrprof_error::bad_header:
40 return "Invalid instrumentation profile data (file header is corrupt)";
41 case instrprof_error::unsupported_version:
42 return "Unsupported instrumentation profile format version";
43 case instrprof_error::unsupported_hash_type:
44 return "Unsupported instrumentation profile hash type";
45 case instrprof_error::too_large:
46 return "Too much profile data";
47 case instrprof_error::truncated:
48 return "Truncated profile data";
49 case instrprof_error::malformed:
50 return "Malformed instrumentation profile data";
51 case instrprof_error::unknown_function:
52 return "No profile data available for function";
53 case instrprof_error::hash_mismatch:
54 return "Function control flow change detected (hash mismatch)";
55 case instrprof_error::count_mismatch:
56 return "Function basic block count change detected (counter mismatch)";
57 case instrprof_error::counter_overflow:
58 return "Counter overflow";
59 case instrprof_error::value_site_count_mismatch:
60 return "Function value site count change detected (counter mismatch)";
62 llvm_unreachable("A value of instrprof_error has no message.");
67 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
69 const std::error_category &llvm::instrprof_category() {
70 return *ErrorCategory;
75 std::string getPGOFuncName(StringRef RawFuncName,
76 GlobalValue::LinkageTypes Linkage,
78 uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
80 // Function names may be prefixed with a binary '1' to indicate
81 // that the backend should not modify the symbols due to any platform
82 // naming convention. Do not include that '1' in the PGO profile name.
83 if (RawFuncName[0] == '\1')
84 RawFuncName = RawFuncName.substr(1);
86 std::string FuncName = RawFuncName;
87 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
88 // For local symbols, prepend the main file name to distinguish them.
89 // Do not include the full path in the file name since there's no guarantee
90 // that it will stay the same, e.g., if the files are checked out from
91 // version control in different locations.
93 FuncName = FuncName.insert(0, "<unknown>:");
95 FuncName = FuncName.insert(0, FileName.str() + ":");
100 std::string getPGOFuncName(const Function &F, uint64_t Version) {
101 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName(),
105 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
106 if (FileName.empty())
108 // Drop the file name including ':'. See also getPGOFuncName.
109 if (PGOFuncName.startswith(FileName))
110 PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
114 // \p FuncName is the string used as profile lookup key for the function. A
115 // symbol is created to hold the name. Return the legalized symbol name.
116 static std::string getPGOFuncNameVarName(StringRef FuncName,
117 GlobalValue::LinkageTypes Linkage) {
118 std::string VarName = getInstrProfNameVarPrefix();
121 if (!GlobalValue::isLocalLinkage(Linkage))
124 // Now fix up illegal chars in local VarName that may upset the assembler.
125 const char *InvalidChars = "-:<>\"'";
126 size_t found = VarName.find_first_of(InvalidChars);
127 while (found != std::string::npos) {
128 VarName[found] = '_';
129 found = VarName.find_first_of(InvalidChars, found + 1);
134 GlobalVariable *createPGOFuncNameVar(Module &M,
135 GlobalValue::LinkageTypes Linkage,
136 StringRef FuncName) {
138 // We generally want to match the function's linkage, but available_externally
139 // and extern_weak both have the wrong semantics, and anything that doesn't
140 // need to link across compilation units doesn't need to be visible at all.
141 if (Linkage == GlobalValue::ExternalWeakLinkage)
142 Linkage = GlobalValue::LinkOnceAnyLinkage;
143 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
144 Linkage = GlobalValue::LinkOnceODRLinkage;
145 else if (Linkage == GlobalValue::InternalLinkage ||
146 Linkage == GlobalValue::ExternalLinkage)
147 Linkage = GlobalValue::PrivateLinkage;
149 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
151 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
152 getPGOFuncNameVarName(FuncName, Linkage));
154 // Hide the symbol so that we correctly get a copy for each executable.
155 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
156 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
161 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
162 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
165 // Merge Value Profile data from Src record to this record for ValueKind.
166 // Scale merged value counts by \p Weight.
167 instrprof_error InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
168 InstrProfRecord &Src,
170 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
171 uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
172 if (ThisNumValueSites != OtherNumValueSites)
173 return instrprof_error::value_site_count_mismatch;
174 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
175 getValueSitesForKind(ValueKind);
176 std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
177 Src.getValueSitesForKind(ValueKind);
178 instrprof_error Result = instrprof_error::success;
179 for (uint32_t I = 0; I < ThisNumValueSites; I++)
181 ThisSiteRecords[I].mergeValueData(OtherSiteRecords[I], Weight));
185 instrprof_error InstrProfRecord::merge(InstrProfRecord &Other,
187 // If the number of counters doesn't match we either have bad data
188 // or a hash collision.
189 if (Counts.size() != Other.Counts.size())
190 return instrprof_error::count_mismatch;
192 instrprof_error Result = instrprof_error::success;
194 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
196 uint64_t OtherCount = Other.Counts[I];
198 OtherCount = SaturatingMultiply(OtherCount, Weight, &Overflowed);
200 Result = instrprof_error::counter_overflow;
202 Counts[I] = SaturatingAdd(Counts[I], OtherCount, &Overflowed);
204 Result = instrprof_error::counter_overflow;
207 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
208 MergeResult(Result, mergeValueProfData(Kind, Other, Weight));
212 // Map indirect call target name hash to name string.
213 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
214 ValueMapType *HashKeys) {
218 case IPVK_IndirectCallTarget: {
220 std::lower_bound(HashKeys->begin(), HashKeys->end(), Value,
221 [](const std::pair<uint64_t, const char *> &LHS,
222 uint64_t RHS) { return LHS.first < RHS; });
223 if (Result != HashKeys->end())
224 Value = (uint64_t)Result->second;
231 void InstrProfRecord::updateStrings(InstrProfStringTable *StrTab) {
235 Name = StrTab->insertString(Name);
236 for (auto &VSite : IndirectCallSites)
237 for (auto &VData : VSite.ValueData)
238 VData.Value = (uint64_t)StrTab->insertString((const char *)VData.Value);
241 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
242 InstrProfValueData *VData, uint32_t N,
243 ValueMapType *HashKeys) {
244 for (uint32_t I = 0; I < N; I++) {
245 VData[I].Value = remapValue(VData[I].Value, ValueKind, HashKeys);
247 std::vector<InstrProfValueSiteRecord> &ValueSites =
248 getValueSitesForKind(ValueKind);
250 ValueSites.push_back(InstrProfValueSiteRecord());
252 ValueSites.emplace_back(VData, VData + N);
255 #define INSTR_PROF_COMMON_API_IMPL
256 #include "llvm/ProfileData/InstrProfData.inc"
259 * \brief ValueProfRecordClosure Interface implementation for InstrProfRecord
260 * class. These C wrappers are used as adaptors so that C++ code can be
261 * invoked as callbacks.
263 uint32_t getNumValueKindsInstrProf(const void *Record) {
264 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
267 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
268 return reinterpret_cast<const InstrProfRecord *>(Record)
269 ->getNumValueSites(VKind);
272 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
273 return reinterpret_cast<const InstrProfRecord *>(Record)
274 ->getNumValueData(VKind);
277 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
279 return reinterpret_cast<const InstrProfRecord *>(R)
280 ->getNumValueDataForSite(VK, S);
283 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
284 uint32_t K, uint32_t S,
285 uint64_t (*Mapper)(uint32_t, uint64_t)) {
286 return reinterpret_cast<const InstrProfRecord *>(R)
287 ->getValueForSite(Dst, K, S, Mapper);
290 uint64_t stringToHash(uint32_t ValueKind, uint64_t Value) {
292 case IPVK_IndirectCallTarget:
293 return IndexedInstrProf::ComputeHash((const char *)Value);
296 llvm_unreachable("value kind not handled !");
301 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
303 (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
304 memset(VD, 0, TotalSizeInBytes);
308 static ValueProfRecordClosure InstrProfRecordClosure = {
310 getNumValueKindsInstrProf,
311 getNumValueSitesInstrProf,
312 getNumValueDataInstrProf,
313 getNumValueDataForSiteInstrProf,
315 getValueForSiteInstrProf,
316 allocValueProfDataInstrProf};
318 // Wrapper implementation using the closure mechanism.
319 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
320 InstrProfRecordClosure.Record = &Record;
321 return getValueProfDataSize(&InstrProfRecordClosure);
324 // Wrapper implementation using the closure mechanism.
325 std::unique_ptr<ValueProfData>
326 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
327 InstrProfRecordClosure.Record = &Record;
329 std::unique_ptr<ValueProfData> VPD(
330 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
334 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
335 InstrProfRecord::ValueMapType *VMap) {
336 Record.reserveSites(Kind, NumValueSites);
338 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
339 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
340 uint8_t ValueDataCount = this->SiteCountArray[VSite];
341 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
342 ValueData += ValueDataCount;
346 // For writing/serializing, Old is the host endianness, and New is
347 // byte order intended on disk. For Reading/deserialization, Old
348 // is the on-disk source endianness, and New is the host endianness.
349 void ValueProfRecord::swapBytes(support::endianness Old,
350 support::endianness New) {
351 using namespace support;
355 if (getHostEndianness() != Old) {
356 sys::swapByteOrder<uint32_t>(NumValueSites);
357 sys::swapByteOrder<uint32_t>(Kind);
359 uint32_t ND = getValueProfRecordNumValueData(this);
360 InstrProfValueData *VD = getValueProfRecordValueData(this);
362 // No need to swap byte array: SiteCountArrray.
363 for (uint32_t I = 0; I < ND; I++) {
364 sys::swapByteOrder<uint64_t>(VD[I].Value);
365 sys::swapByteOrder<uint64_t>(VD[I].Count);
367 if (getHostEndianness() == Old) {
368 sys::swapByteOrder<uint32_t>(NumValueSites);
369 sys::swapByteOrder<uint32_t>(Kind);
373 void ValueProfData::deserializeTo(InstrProfRecord &Record,
374 InstrProfRecord::ValueMapType *VMap) {
375 if (NumValueKinds == 0)
378 ValueProfRecord *VR = getFirstValueProfRecord(this);
379 for (uint32_t K = 0; K < NumValueKinds; K++) {
380 VR->deserializeTo(Record, VMap);
381 VR = getValueProfRecordNext(VR);
386 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
387 using namespace support;
389 return endian::readNext<T, little, unaligned>(D);
391 return endian::readNext<T, big, unaligned>(D);
394 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
395 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
399 instrprof_error ValueProfData::checkIntegrity() {
400 if (NumValueKinds > IPVK_Last + 1)
401 return instrprof_error::malformed;
402 // Total size needs to be mulltiple of quadword size.
403 if (TotalSize % sizeof(uint64_t))
404 return instrprof_error::malformed;
406 ValueProfRecord *VR = getFirstValueProfRecord(this);
407 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
408 if (VR->Kind > IPVK_Last)
409 return instrprof_error::malformed;
410 VR = getValueProfRecordNext(VR);
411 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
412 return instrprof_error::malformed;
414 return instrprof_error::success;
417 ErrorOr<std::unique_ptr<ValueProfData>>
418 ValueProfData::getValueProfData(const unsigned char *D,
419 const unsigned char *const BufferEnd,
420 support::endianness Endianness) {
421 using namespace support;
422 if (D + sizeof(ValueProfData) > BufferEnd)
423 return instrprof_error::truncated;
425 const unsigned char *Header = D;
426 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
427 if (D + TotalSize > BufferEnd)
428 return instrprof_error::too_large;
430 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
431 memcpy(VPD.get(), D, TotalSize);
433 VPD->swapBytesToHost(Endianness);
435 instrprof_error EC = VPD->checkIntegrity();
436 if (EC != instrprof_error::success)
439 return std::move(VPD);
442 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
443 using namespace support;
444 if (Endianness == getHostEndianness())
447 sys::swapByteOrder<uint32_t>(TotalSize);
448 sys::swapByteOrder<uint32_t>(NumValueKinds);
450 ValueProfRecord *VR = getFirstValueProfRecord(this);
451 for (uint32_t K = 0; K < NumValueKinds; K++) {
452 VR->swapBytes(Endianness, getHostEndianness());
453 VR = getValueProfRecordNext(VR);
457 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
458 using namespace support;
459 if (Endianness == getHostEndianness())
462 ValueProfRecord *VR = getFirstValueProfRecord(this);
463 for (uint32_t K = 0; K < NumValueKinds; K++) {
464 ValueProfRecord *NVR = getValueProfRecordNext(VR);
465 VR->swapBytes(getHostEndianness(), Endianness);
468 sys::swapByteOrder<uint32_t>(TotalSize);
469 sys::swapByteOrder<uint32_t>(NumValueKinds);