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,
77 StringRef FileName, uint64_t Version) {
79 // Function names may be prefixed with a binary '1' to indicate
80 // that the backend should not modify the symbols due to any platform
81 // naming convention. Do not include that '1' in the PGO profile name.
82 if (RawFuncName[0] == '\1')
83 RawFuncName = RawFuncName.substr(1);
84 const char *Unknown = (Version <= 3 ? "<unknown>:" : "__unknown__");
85 const char *Sep = (Version <= 3 ? ":" : "__");
87 std::string FuncName = RawFuncName;
88 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
89 // For local symbols, prepend the main file name to distinguish them.
90 // Do not include the full path in the file name since there's no guarantee
91 // that it will stay the same, e.g., if the files are checked out from
92 // version control in different locations.
94 FuncName = FuncName.insert(0, Unknown);
96 FuncName = FuncName.insert(0, FileName.str() + Sep);
101 std::string getPGOFuncName(const Function &F, uint64_t Version) {
102 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName(),
106 GlobalVariable *createPGOFuncNameVar(Module &M,
107 GlobalValue::LinkageTypes Linkage,
108 StringRef FuncName) {
110 // We generally want to match the function's linkage, but available_externally
111 // and extern_weak both have the wrong semantics, and anything that doesn't
112 // need to link across compilation units doesn't need to be visible at all.
113 if (Linkage == GlobalValue::ExternalWeakLinkage)
114 Linkage = GlobalValue::LinkOnceAnyLinkage;
115 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
116 Linkage = GlobalValue::LinkOnceODRLinkage;
117 else if (Linkage == GlobalValue::InternalLinkage ||
118 Linkage == GlobalValue::ExternalLinkage)
119 Linkage = GlobalValue::PrivateLinkage;
121 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
123 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
124 Twine(getInstrProfNameVarPrefix()) + FuncName);
126 // Hide the symbol so that we correctly get a copy for each executable.
127 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
128 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
133 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
134 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
137 #define INSTR_PROF_COMMON_API_IMPL
138 #include "llvm/ProfileData/InstrProfData.inc"
142 * \brief ValueProfRecordClosure Interface implementation for InstrProfRecord
143 * class. These C wrappers are used as adaptors so that C++ code can be
144 * invoked as callbacks.
146 uint32_t getNumValueKindsInstrProf(const void *Record) {
147 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
150 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
151 return reinterpret_cast<const InstrProfRecord *>(Record)
152 ->getNumValueSites(VKind);
155 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
156 return reinterpret_cast<const InstrProfRecord *>(Record)
157 ->getNumValueData(VKind);
160 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
162 return reinterpret_cast<const InstrProfRecord *>(R)
163 ->getNumValueDataForSite(VK, S);
166 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
167 uint32_t K, uint32_t S,
168 uint64_t (*Mapper)(uint32_t, uint64_t)) {
169 return reinterpret_cast<const InstrProfRecord *>(R)
170 ->getValueForSite(Dst, K, S, Mapper);
173 uint64_t stringToHash(uint32_t ValueKind, uint64_t Value) {
175 case IPVK_IndirectCallTarget:
176 return IndexedInstrProf::ComputeHash(IndexedInstrProf::HashType,
177 (const char *)Value);
180 llvm_unreachable("value kind not handled !");
185 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
186 return (ValueProfData *)(new (::operator new(TotalSizeInBytes))
190 static ValueProfRecordClosure InstrProfRecordClosure = {
192 getNumValueKindsInstrProf,
193 getNumValueSitesInstrProf,
194 getNumValueDataInstrProf,
195 getNumValueDataForSiteInstrProf,
197 getValueForSiteInstrProf,
198 allocValueProfDataInstrProf
201 // Wrapper implementation using the closure mechanism.
202 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
203 InstrProfRecordClosure.Record = &Record;
204 return getValueProfDataSize(&InstrProfRecordClosure);
207 // Wrapper implementation using the closure mechanism.
208 std::unique_ptr<ValueProfData>
209 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
210 InstrProfRecordClosure.Record = &Record;
212 std::unique_ptr<ValueProfData> VPD(
213 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
217 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
218 InstrProfRecord::ValueMapType *VMap) {
219 Record.reserveSites(Kind, NumValueSites);
221 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
222 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
223 uint8_t ValueDataCount = this->SiteCountArray[VSite];
224 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
225 ValueData += ValueDataCount;
229 // For writing/serializing, Old is the host endianness, and New is
230 // byte order intended on disk. For Reading/deserialization, Old
231 // is the on-disk source endianness, and New is the host endianness.
232 void ValueProfRecord::swapBytes(support::endianness Old,
233 support::endianness New) {
234 using namespace support;
238 if (getHostEndianness() != Old) {
239 sys::swapByteOrder<uint32_t>(NumValueSites);
240 sys::swapByteOrder<uint32_t>(Kind);
242 uint32_t ND = getValueProfRecordNumValueData(this);
243 InstrProfValueData *VD = getValueProfRecordValueData(this);
245 // No need to swap byte array: SiteCountArrray.
246 for (uint32_t I = 0; I < ND; I++) {
247 sys::swapByteOrder<uint64_t>(VD[I].Value);
248 sys::swapByteOrder<uint64_t>(VD[I].Count);
250 if (getHostEndianness() == Old) {
251 sys::swapByteOrder<uint32_t>(NumValueSites);
252 sys::swapByteOrder<uint32_t>(Kind);
256 void ValueProfData::deserializeTo(InstrProfRecord &Record,
257 InstrProfRecord::ValueMapType *VMap) {
258 if (NumValueKinds == 0)
261 ValueProfRecord *VR = getFirstValueProfRecord(this);
262 for (uint32_t K = 0; K < NumValueKinds; K++) {
263 VR->deserializeTo(Record, VMap);
264 VR = getValueProfRecordNext(VR);
269 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
270 using namespace support;
272 return endian::readNext<T, little, unaligned>(D);
274 return endian::readNext<T, big, unaligned>(D);
277 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
278 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
282 instrprof_error ValueProfData::checkIntegrity() {
283 if (NumValueKinds > IPVK_Last + 1)
284 return instrprof_error::malformed;
285 // Total size needs to be mulltiple of quadword size.
286 if (TotalSize % sizeof(uint64_t))
287 return instrprof_error::malformed;
289 ValueProfRecord *VR = getFirstValueProfRecord(this);
290 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
291 if (VR->Kind > IPVK_Last)
292 return instrprof_error::malformed;
293 VR = getValueProfRecordNext(VR);
294 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
295 return instrprof_error::malformed;
297 return instrprof_error::success;
300 ErrorOr<std::unique_ptr<ValueProfData>>
301 ValueProfData::getValueProfData(const unsigned char *D,
302 const unsigned char *const BufferEnd,
303 support::endianness Endianness) {
304 using namespace support;
305 if (D + sizeof(ValueProfData) > BufferEnd)
306 return instrprof_error::truncated;
308 const unsigned char *Header = D;
309 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
310 if (D + TotalSize > BufferEnd)
311 return instrprof_error::too_large;
313 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
314 memcpy(VPD.get(), D, TotalSize);
316 VPD->swapBytesToHost(Endianness);
318 instrprof_error EC = VPD->checkIntegrity();
319 if (EC != instrprof_error::success)
322 return std::move(VPD);
325 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
326 using namespace support;
327 if (Endianness == getHostEndianness())
330 sys::swapByteOrder<uint32_t>(TotalSize);
331 sys::swapByteOrder<uint32_t>(NumValueKinds);
333 ValueProfRecord *VR = getFirstValueProfRecord(this);
334 for (uint32_t K = 0; K < NumValueKinds; K++) {
335 VR->swapBytes(Endianness, getHostEndianness());
336 VR = getValueProfRecordNext(VR);
340 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
341 using namespace support;
342 if (Endianness == getHostEndianness())
345 ValueProfRecord *VR = getFirstValueProfRecord(this);
346 for (uint32_t K = 0; K < NumValueKinds; K++) {
347 ValueProfRecord *NVR = getValueProfRecordNext(VR);
348 VR->swapBytes(getHostEndianness(), Endianness);
351 sys::swapByteOrder<uint32_t>(TotalSize);
352 sys::swapByteOrder<uint32_t>(NumValueKinds);