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::bad_magic:
36 return "Invalid profile data (bad magic)";
37 case instrprof_error::bad_header:
38 return "Invalid profile data (file header is corrupt)";
39 case instrprof_error::unsupported_version:
40 return "Unsupported profiling format version";
41 case instrprof_error::unsupported_hash_type:
42 return "Unsupported profiling hash";
43 case instrprof_error::too_large:
44 return "Too much profile data";
45 case instrprof_error::truncated:
46 return "Truncated profile data";
47 case instrprof_error::malformed:
48 return "Malformed profile data";
49 case instrprof_error::unknown_function:
50 return "No profile data available for function";
51 case instrprof_error::hash_mismatch:
52 return "Function hash mismatch";
53 case instrprof_error::count_mismatch:
54 return "Function count mismatch";
55 case instrprof_error::counter_overflow:
56 return "Counter overflow";
57 case instrprof_error::value_site_count_mismatch:
58 return "Function's value site counts mismatch";
60 llvm_unreachable("A value of instrprof_error has no message.");
65 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
67 const std::error_category &llvm::instrprof_category() {
68 return *ErrorCategory;
73 std::string getPGOFuncName(StringRef RawFuncName,
74 GlobalValue::LinkageTypes Linkage,
77 // Function names may be prefixed with a binary '1' to indicate
78 // that the backend should not modify the symbols due to any platform
79 // naming convention. Do not include that '1' in the PGO profile name.
80 if (RawFuncName[0] == '\1')
81 RawFuncName = RawFuncName.substr(1);
83 std::string FuncName = RawFuncName;
84 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
85 // For local symbols, prepend the main file name to distinguish them.
86 // Do not include the full path in the file name since there's no guarantee
87 // that it will stay the same, e.g., if the files are checked out from
88 // version control in different locations.
90 FuncName = FuncName.insert(0, "<unknown>:");
92 FuncName = FuncName.insert(0, FileName.str() + ":");
97 std::string getPGOFuncName(const Function &F) {
98 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName());
101 GlobalVariable *createPGOFuncNameVar(Module &M,
102 GlobalValue::LinkageTypes Linkage,
103 StringRef FuncName) {
105 // We generally want to match the function's linkage, but available_externally
106 // and extern_weak both have the wrong semantics, and anything that doesn't
107 // need to link across compilation units doesn't need to be visible at all.
108 if (Linkage == GlobalValue::ExternalWeakLinkage)
109 Linkage = GlobalValue::LinkOnceAnyLinkage;
110 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
111 Linkage = GlobalValue::LinkOnceODRLinkage;
112 else if (Linkage == GlobalValue::InternalLinkage ||
113 Linkage == GlobalValue::ExternalLinkage)
114 Linkage = GlobalValue::PrivateLinkage;
116 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
118 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
119 Twine(getInstrProfNameVarPrefix()) + FuncName);
121 // Hide the symbol so that we correctly get a copy for each executable.
122 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
123 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
128 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
129 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
132 namespace IndexedInstrProf {
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 = ComputeHash(HashType, (const char *)DstVD[I].Value);
178 llvm_unreachable("value kind not handled !");
185 template <class T> static T swapToHostOrder(T v, support::endianness Orig) {
186 if (Orig == getHostEndianness())
188 sys::swapByteOrder<T>(v);
192 // For writing/serializing, Old is the host endianness, and New is
193 // byte order intended on disk. For Reading/deserialization, Old
194 // is the on-disk source endianness, and New is the host endianness.
195 void ValueProfRecord::swapBytes(support::endianness Old,
196 support::endianness New) {
197 using namespace support;
201 if (getHostEndianness() != Old) {
202 sys::swapByteOrder<uint32_t>(NumValueSites);
203 sys::swapByteOrder<uint32_t>(Kind);
205 uint32_t ND = getNumValueData();
206 InstrProfValueData *VD = getValueData();
208 // No need to swap byte array: SiteCountArrray.
209 for (uint32_t I = 0; I < ND; I++) {
210 sys::swapByteOrder<uint64_t>(VD[I].Value);
211 sys::swapByteOrder<uint64_t>(VD[I].Count);
213 if (getHostEndianness() == Old) {
214 sys::swapByteOrder<uint32_t>(NumValueSites);
215 sys::swapByteOrder<uint32_t>(Kind);
219 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
220 uint32_t TotalSize = sizeof(ValueProfData);
221 uint32_t NumValueKinds = Record.getNumValueKinds();
222 if (NumValueKinds == 0)
225 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; Kind++) {
226 uint32_t NumValueSites = Record.getNumValueSites(Kind);
230 ValueProfRecord::getSize(NumValueSites, Record.getNumValueData(Kind));
235 void ValueProfData::deserializeTo(InstrProfRecord &Record,
236 InstrProfRecord::ValueMapType *VMap) {
237 if (NumValueKinds == 0)
240 ValueProfRecord *VR = getFirstValueProfRecord();
241 for (uint32_t K = 0; K < NumValueKinds; K++) {
242 VR->deserializeTo(Record, VMap);
247 static std::unique_ptr<ValueProfData> AllocValueProfData(uint32_t TotalSize) {
248 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
252 std::unique_ptr<ValueProfData>
253 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
254 uint32_t TotalSize = getSize(Record);
256 std::unique_ptr<ValueProfData> VPD = AllocValueProfData(TotalSize);
258 VPD->TotalSize = TotalSize;
259 VPD->NumValueKinds = Record.getNumValueKinds();
260 ValueProfRecord *VR = VPD->getFirstValueProfRecord();
261 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; Kind++) {
262 uint32_t NumValueSites = Record.getNumValueSites(Kind);
265 VR->serializeFrom(Record, Kind, NumValueSites);
271 ErrorOr<std::unique_ptr<ValueProfData>>
272 ValueProfData::getValueProfData(const unsigned char *D,
273 const unsigned char *const BufferEnd,
274 support::endianness Endianness) {
275 using namespace support;
276 if (D + sizeof(ValueProfData) > BufferEnd)
277 return instrprof_error::truncated;
279 uint32_t TotalSize = swapToHostOrder<uint32_t>(
280 reinterpret_cast<const uint32_t *>(D)[0], Endianness);
281 uint32_t NumValueKinds = swapToHostOrder<uint32_t>(
282 reinterpret_cast<const uint32_t *>(D)[1], Endianness);
284 if (D + TotalSize > BufferEnd)
285 return instrprof_error::too_large;
286 if (NumValueKinds > IPVK_Last + 1)
287 return instrprof_error::malformed;
288 // Total size needs to be mulltiple of quadword size.
289 if (TotalSize % sizeof(uint64_t))
290 return instrprof_error::malformed;
292 std::unique_ptr<ValueProfData> VPD = AllocValueProfData(TotalSize);
294 memcpy(VPD.get(), D, TotalSize);
296 VPD->swapBytesToHost(Endianness);
298 // Data integrety check:
299 ValueProfRecord *VR = VPD->getFirstValueProfRecord();
300 for (uint32_t K = 0; K < VPD->NumValueKinds; K++) {
301 if (VR->Kind > IPVK_Last)
302 return instrprof_error::malformed;
304 if ((char *)VR - (char *)VPD.get() > (ptrdiff_t)TotalSize)
305 return instrprof_error::malformed;
309 return std::move(VPD);
312 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
313 using namespace support;
314 if (Endianness == getHostEndianness())
317 sys::swapByteOrder<uint32_t>(TotalSize);
318 sys::swapByteOrder<uint32_t>(NumValueKinds);
320 ValueProfRecord *VR = getFirstValueProfRecord();
321 for (uint32_t K = 0; K < NumValueKinds; K++) {
322 VR->swapBytes(Endianness, getHostEndianness());
327 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
328 using namespace support;
329 if (Endianness == getHostEndianness())
332 ValueProfRecord *VR = getFirstValueProfRecord();
333 for (uint32_t K = 0; K < NumValueKinds; K++) {
334 ValueProfRecord *NVR = VR->getNext();
335 VR->swapBytes(getHostEndianness(), Endianness);
338 sys::swapByteOrder<uint32_t>(TotalSize);
339 sys::swapByteOrder<uint32_t>(NumValueKinds);
342 ValueProfRecord *ValueProfData::getFirstValueProfRecord() {
343 return reinterpret_cast<ValueProfRecord *>((char *)this +
344 sizeof(ValueProfData));
347 uint32_t ValueProfRecord::getNumValueData() const {
348 uint32_t NumValueData = 0;
349 for (uint32_t I = 0; I < NumValueSites; I++)
350 NumValueData += SiteCountArray[I];
354 ValueProfRecord *ValueProfRecord::getNext() {
355 return reinterpret_cast<ValueProfRecord *>((char *)this + getSize());
358 InstrProfValueData *ValueProfRecord::getValueData() {
359 return reinterpret_cast<InstrProfValueData *>((char *)this +
360 getHeaderSize(NumValueSites));
363 } // End of IndexedInstrProf namespace.