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,
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);
85 std::string FuncName = RawFuncName;
86 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
87 // For local symbols, prepend the main file name to distinguish them.
88 // Do not include the full path in the file name since there's no guarantee
89 // that it will stay the same, e.g., if the files are checked out from
90 // version control in different locations.
92 FuncName = FuncName.insert(0, "<unknown>:");
94 FuncName = FuncName.insert(0, FileName.str() + ":");
99 std::string getPGOFuncName(const Function &F) {
100 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName());
103 GlobalVariable *createPGOFuncNameVar(Module &M,
104 GlobalValue::LinkageTypes Linkage,
105 StringRef FuncName) {
107 // We generally want to match the function's linkage, but available_externally
108 // and extern_weak both have the wrong semantics, and anything that doesn't
109 // need to link across compilation units doesn't need to be visible at all.
110 if (Linkage == GlobalValue::ExternalWeakLinkage)
111 Linkage = GlobalValue::LinkOnceAnyLinkage;
112 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
113 Linkage = GlobalValue::LinkOnceODRLinkage;
114 else if (Linkage == GlobalValue::InternalLinkage ||
115 Linkage == GlobalValue::ExternalLinkage)
116 Linkage = GlobalValue::PrivateLinkage;
118 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
120 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
121 Twine(getInstrProfNameVarPrefix()) + FuncName);
123 // Hide the symbol so that we correctly get a copy for each executable.
124 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
125 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
130 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
131 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
134 uint32_t ValueProfRecord::getHeaderSize(uint32_t NumValueSites) {
135 uint32_t Size = offsetof(ValueProfRecord, SiteCountArray) +
136 sizeof(uint8_t) * NumValueSites;
137 // Round the size to multiple of 8 bytes.
138 Size = (Size + 7) & ~7;
142 uint32_t ValueProfRecord::getSize(uint32_t NumValueSites,
143 uint32_t NumValueData) {
144 return getHeaderSize(NumValueSites) +
145 sizeof(InstrProfValueData) * NumValueData;
148 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
149 InstrProfRecord::ValueMapType *VMap) {
150 Record.reserveSites(Kind, NumValueSites);
152 InstrProfValueData *ValueData = this->getValueData();
153 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
154 uint8_t ValueDataCount = this->SiteCountArray[VSite];
155 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
156 ValueData += ValueDataCount;
160 void ValueProfRecord::serializeFrom(const InstrProfRecord &Record,
162 uint32_t NumValueSites) {
164 this->NumValueSites = NumValueSites;
165 InstrProfValueData *DstVD = getValueData();
166 for (uint32_t S = 0; S < NumValueSites; S++) {
167 uint32_t ND = Record.getNumValueDataForSite(ValueKind, S);
168 SiteCountArray[S] = ND;
169 std::unique_ptr<InstrProfValueData[]> SrcVD =
170 Record.getValueForSite(ValueKind, S);
171 for (uint32_t I = 0; I < ND; I++) {
174 case IPVK_IndirectCallTarget:
175 DstVD[I].Value = IndexedInstrProf::ComputeHash(
176 IndexedInstrProf::HashType, (const char *)DstVD[I].Value);
179 llvm_unreachable("value kind not handled !");
187 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
188 using namespace support;
190 return endian::readNext<T, little, unaligned>(D);
192 return endian::readNext<T, big, unaligned>(D);
195 // For writing/serializing, Old is the host endianness, and New is
196 // byte order intended on disk. For Reading/deserialization, Old
197 // is the on-disk source endianness, and New is the host endianness.
198 void ValueProfRecord::swapBytes(support::endianness Old,
199 support::endianness New) {
200 using namespace support;
204 if (getHostEndianness() != Old) {
205 sys::swapByteOrder<uint32_t>(NumValueSites);
206 sys::swapByteOrder<uint32_t>(Kind);
208 uint32_t ND = getNumValueData();
209 InstrProfValueData *VD = getValueData();
211 // No need to swap byte array: SiteCountArrray.
212 for (uint32_t I = 0; I < ND; I++) {
213 sys::swapByteOrder<uint64_t>(VD[I].Value);
214 sys::swapByteOrder<uint64_t>(VD[I].Count);
216 if (getHostEndianness() == Old) {
217 sys::swapByteOrder<uint32_t>(NumValueSites);
218 sys::swapByteOrder<uint32_t>(Kind);
222 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
223 uint32_t TotalSize = sizeof(ValueProfData);
224 uint32_t NumValueKinds = Record.getNumValueKinds();
225 if (NumValueKinds == 0)
228 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; Kind++) {
229 uint32_t NumValueSites = Record.getNumValueSites(Kind);
233 ValueProfRecord::getSize(NumValueSites, Record.getNumValueData(Kind));
238 void ValueProfData::deserializeTo(InstrProfRecord &Record,
239 InstrProfRecord::ValueMapType *VMap) {
240 if (NumValueKinds == 0)
243 ValueProfRecord *VR = getFirstValueProfRecord();
244 for (uint32_t K = 0; K < NumValueKinds; K++) {
245 VR->deserializeTo(Record, VMap);
250 static std::unique_ptr<ValueProfData> AllocValueProfData(uint32_t TotalSize) {
251 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
255 std::unique_ptr<ValueProfData>
256 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
257 uint32_t TotalSize = getSize(Record);
259 std::unique_ptr<ValueProfData> VPD = AllocValueProfData(TotalSize);
261 VPD->TotalSize = TotalSize;
262 VPD->NumValueKinds = Record.getNumValueKinds();
263 ValueProfRecord *VR = VPD->getFirstValueProfRecord();
264 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; Kind++) {
265 uint32_t NumValueSites = Record.getNumValueSites(Kind);
268 VR->serializeFrom(Record, Kind, NumValueSites);
274 ErrorOr<std::unique_ptr<ValueProfData>>
275 ValueProfData::getValueProfData(const unsigned char *D,
276 const unsigned char *const BufferEnd,
277 support::endianness Endianness) {
278 using namespace support;
279 if (D + sizeof(ValueProfData) > BufferEnd)
280 return instrprof_error::truncated;
282 const unsigned char *Header = D;
283 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
284 uint32_t NumValueKinds = swapToHostOrder<uint32_t>(Header, Endianness);
286 if (D + TotalSize > BufferEnd)
287 return instrprof_error::too_large;
288 if (NumValueKinds > IPVK_Last + 1)
289 return instrprof_error::malformed;
290 // Total size needs to be mulltiple of quadword size.
291 if (TotalSize % sizeof(uint64_t))
292 return instrprof_error::malformed;
294 std::unique_ptr<ValueProfData> VPD = AllocValueProfData(TotalSize);
296 memcpy(VPD.get(), D, TotalSize);
298 VPD->swapBytesToHost(Endianness);
300 // Data integrety check:
301 ValueProfRecord *VR = VPD->getFirstValueProfRecord();
302 for (uint32_t K = 0; K < VPD->NumValueKinds; K++) {
303 if (VR->Kind > IPVK_Last)
304 return instrprof_error::malformed;
306 if ((char *)VR - (char *)VPD.get() > (ptrdiff_t)TotalSize)
307 return instrprof_error::malformed;
310 return std::move(VPD);
313 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
314 using namespace support;
315 if (Endianness == getHostEndianness())
318 sys::swapByteOrder<uint32_t>(TotalSize);
319 sys::swapByteOrder<uint32_t>(NumValueKinds);
321 ValueProfRecord *VR = getFirstValueProfRecord();
322 for (uint32_t K = 0; K < NumValueKinds; K++) {
323 VR->swapBytes(Endianness, getHostEndianness());
328 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
329 using namespace support;
330 if (Endianness == getHostEndianness())
333 ValueProfRecord *VR = getFirstValueProfRecord();
334 for (uint32_t K = 0; K < NumValueKinds; K++) {
335 ValueProfRecord *NVR = VR->getNext();
336 VR->swapBytes(getHostEndianness(), Endianness);
339 sys::swapByteOrder<uint32_t>(TotalSize);
340 sys::swapByteOrder<uint32_t>(NumValueKinds);
343 ValueProfRecord *ValueProfData::getFirstValueProfRecord() {
344 return reinterpret_cast<ValueProfRecord *>((char *)this +
345 sizeof(ValueProfData));
348 uint32_t ValueProfRecord::getNumValueData() const {
349 uint32_t NumValueData = 0;
350 for (uint32_t I = 0; I < NumValueSites; I++)
351 NumValueData += SiteCountArray[I];
355 ValueProfRecord *ValueProfRecord::getNext() {
356 return reinterpret_cast<ValueProfRecord *>((char *)this + getSize());
359 InstrProfValueData *ValueProfRecord::getValueData() {
360 return reinterpret_cast<InstrProfValueData *>((char *)this +
361 getHeaderSize(NumValueSites));