1 //===- InstrProf.cpp - Instrumented profiling format support --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains support for clang's instrumentation based PGO and
10 // coverage.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/ProfileData/InstrProf.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/IR/Constant.h"
22 #include "llvm/IR/Constants.h"
23 #include "llvm/IR/Function.h"
24 #include "llvm/IR/GlobalValue.h"
25 #include "llvm/IR/GlobalVariable.h"
26 #include "llvm/IR/Instruction.h"
27 #include "llvm/IR/LLVMContext.h"
28 #include "llvm/IR/MDBuilder.h"
29 #include "llvm/IR/Metadata.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/Type.h"
32 #include "llvm/ProfileData/InstrProfReader.h"
33 #include "llvm/Support/Casting.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/Compiler.h"
36 #include "llvm/Support/Compression.h"
37 #include "llvm/Support/Endian.h"
38 #include "llvm/Support/Error.h"
39 #include "llvm/Support/ErrorHandling.h"
40 #include "llvm/Support/LEB128.h"
41 #include "llvm/Support/ManagedStatic.h"
42 #include "llvm/Support/MathExtras.h"
43 #include "llvm/Support/Path.h"
44 #include "llvm/Support/SwapByteOrder.h"
45 #include <algorithm>
46 #include <cassert>
47 #include <cstddef>
48 #include <cstdint>
49 #include <cstring>
50 #include <memory>
51 #include <string>
52 #include <system_error>
53 #include <utility>
54 #include <vector>
55
56 using namespace llvm;
57
58 static cl::opt<bool> StaticFuncFullModulePrefix(
59 "static-func-full-module-prefix", cl::init(true), cl::Hidden,
60 cl::desc("Use full module build paths in the profile counter names for "
61 "static functions."));
62
63 // This option is tailored to users that have different top-level directory in
64 // profile-gen and profile-use compilation. Users need to specific the number
65 // of levels to strip. A value larger than the number of directories in the
66 // source file will strip all the directory names and only leave the basename.
67 //
68 // Note current ThinLTO module importing for the indirect-calls assumes
69 // the source directory name not being stripped. A non-zero option value here
70 // can potentially prevent some inter-module indirect-call-promotions.
71 static cl::opt<unsigned> StaticFuncStripDirNamePrefix(
72 "static-func-strip-dirname-prefix", cl::init(0), cl::Hidden,
73 cl::desc("Strip specified level of directory name from source path in "
74 "the profile counter name for static functions."));
75
getInstrProfErrString(instrprof_error Err)76 static std::string getInstrProfErrString(instrprof_error Err) {
77 switch (Err) {
78 case instrprof_error::success:
79 return "Success";
80 case instrprof_error::eof:
81 return "End of File";
82 case instrprof_error::unrecognized_format:
83 return "Unrecognized instrumentation profile encoding format";
84 case instrprof_error::bad_magic:
85 return "Invalid instrumentation profile data (bad magic)";
86 case instrprof_error::bad_header:
87 return "Invalid instrumentation profile data (file header is corrupt)";
88 case instrprof_error::unsupported_version:
89 return "Unsupported instrumentation profile format version";
90 case instrprof_error::unsupported_hash_type:
91 return "Unsupported instrumentation profile hash type";
92 case instrprof_error::too_large:
93 return "Too much profile data";
94 case instrprof_error::truncated:
95 return "Truncated profile data";
96 case instrprof_error::malformed:
97 return "Malformed instrumentation profile data";
98 case instrprof_error::unknown_function:
99 return "No profile data available for function";
100 case instrprof_error::hash_mismatch:
101 return "Function control flow change detected (hash mismatch)";
102 case instrprof_error::count_mismatch:
103 return "Function basic block count change detected (counter mismatch)";
104 case instrprof_error::counter_overflow:
105 return "Counter overflow";
106 case instrprof_error::value_site_count_mismatch:
107 return "Function value site count change detected (counter mismatch)";
108 case instrprof_error::compress_failed:
109 return "Failed to compress data (zlib)";
110 case instrprof_error::uncompress_failed:
111 return "Failed to uncompress data (zlib)";
112 case instrprof_error::empty_raw_profile:
113 return "Empty raw profile file";
114 case instrprof_error::zlib_unavailable:
115 return "Profile uses zlib compression but the profile reader was built without zlib support";
116 }
117 llvm_unreachable("A value of instrprof_error has no message.");
118 }
119
120 namespace {
121
122 // FIXME: This class is only here to support the transition to llvm::Error. It
123 // will be removed once this transition is complete. Clients should prefer to
124 // deal with the Error value directly, rather than converting to error_code.
125 class InstrProfErrorCategoryType : public std::error_category {
name() const126 const char *name() const noexcept override { return "llvm.instrprof"; }
127
message(int IE) const128 std::string message(int IE) const override {
129 return getInstrProfErrString(static_cast<instrprof_error>(IE));
130 }
131 };
132
133 } // end anonymous namespace
134
135 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
136
instrprof_category()137 const std::error_category &llvm::instrprof_category() {
138 return *ErrorCategory;
139 }
140
141 namespace {
142
143 const char *InstrProfSectNameCommon[] = {
144 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
145 SectNameCommon,
146 #include "llvm/ProfileData/InstrProfData.inc"
147 };
148
149 const char *InstrProfSectNameCoff[] = {
150 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
151 SectNameCoff,
152 #include "llvm/ProfileData/InstrProfData.inc"
153 };
154
155 const char *InstrProfSectNamePrefix[] = {
156 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
157 Prefix,
158 #include "llvm/ProfileData/InstrProfData.inc"
159 };
160
161 } // namespace
162
163 namespace llvm {
164
165 cl::opt<bool> DoInstrProfNameCompression(
166 "enable-name-compression",
167 cl::desc("Enable name/filename string compression"), cl::init(true));
168
getInstrProfSectionName(InstrProfSectKind IPSK,Triple::ObjectFormatType OF,bool AddSegmentInfo)169 std::string getInstrProfSectionName(InstrProfSectKind IPSK,
170 Triple::ObjectFormatType OF,
171 bool AddSegmentInfo) {
172 std::string SectName;
173
174 if (OF == Triple::MachO && AddSegmentInfo)
175 SectName = InstrProfSectNamePrefix[IPSK];
176
177 if (OF == Triple::COFF)
178 SectName += InstrProfSectNameCoff[IPSK];
179 else
180 SectName += InstrProfSectNameCommon[IPSK];
181
182 if (OF == Triple::MachO && IPSK == IPSK_data && AddSegmentInfo)
183 SectName += ",regular,live_support";
184
185 return SectName;
186 }
187
addError(instrprof_error IE)188 void SoftInstrProfErrors::addError(instrprof_error IE) {
189 if (IE == instrprof_error::success)
190 return;
191
192 if (FirstError == instrprof_error::success)
193 FirstError = IE;
194
195 switch (IE) {
196 case instrprof_error::hash_mismatch:
197 ++NumHashMismatches;
198 break;
199 case instrprof_error::count_mismatch:
200 ++NumCountMismatches;
201 break;
202 case instrprof_error::counter_overflow:
203 ++NumCounterOverflows;
204 break;
205 case instrprof_error::value_site_count_mismatch:
206 ++NumValueSiteCountMismatches;
207 break;
208 default:
209 llvm_unreachable("Not a soft error");
210 }
211 }
212
message() const213 std::string InstrProfError::message() const {
214 return getInstrProfErrString(Err);
215 }
216
217 char InstrProfError::ID = 0;
218
getPGOFuncName(StringRef RawFuncName,GlobalValue::LinkageTypes Linkage,StringRef FileName,uint64_t Version LLVM_ATTRIBUTE_UNUSED)219 std::string getPGOFuncName(StringRef RawFuncName,
220 GlobalValue::LinkageTypes Linkage,
221 StringRef FileName,
222 uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
223 return GlobalValue::getGlobalIdentifier(RawFuncName, Linkage, FileName);
224 }
225
226 // Strip NumPrefix level of directory name from PathNameStr. If the number of
227 // directory separators is less than NumPrefix, strip all the directories and
228 // leave base file name only.
stripDirPrefix(StringRef PathNameStr,uint32_t NumPrefix)229 static StringRef stripDirPrefix(StringRef PathNameStr, uint32_t NumPrefix) {
230 uint32_t Count = NumPrefix;
231 uint32_t Pos = 0, LastPos = 0;
232 for (auto & CI : PathNameStr) {
233 ++Pos;
234 if (llvm::sys::path::is_separator(CI)) {
235 LastPos = Pos;
236 --Count;
237 }
238 if (Count == 0)
239 break;
240 }
241 return PathNameStr.substr(LastPos);
242 }
243
244 // Return the PGOFuncName. This function has some special handling when called
245 // in LTO optimization. The following only applies when calling in LTO passes
246 // (when \c InLTO is true): LTO's internalization privatizes many global linkage
247 // symbols. This happens after value profile annotation, but those internal
248 // linkage functions should not have a source prefix.
249 // Additionally, for ThinLTO mode, exported internal functions are promoted
250 // and renamed. We need to ensure that the original internal PGO name is
251 // used when computing the GUID that is compared against the profiled GUIDs.
252 // To differentiate compiler generated internal symbols from original ones,
253 // PGOFuncName meta data are created and attached to the original internal
254 // symbols in the value profile annotation step
255 // (PGOUseFunc::annotateIndirectCallSites). If a symbol does not have the meta
256 // data, its original linkage must be non-internal.
getPGOFuncName(const Function & F,bool InLTO,uint64_t Version)257 std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
258 if (!InLTO) {
259 StringRef FileName(F.getParent()->getSourceFileName());
260 uint32_t StripLevel = StaticFuncFullModulePrefix ? 0 : (uint32_t)-1;
261 if (StripLevel < StaticFuncStripDirNamePrefix)
262 StripLevel = StaticFuncStripDirNamePrefix;
263 if (StripLevel)
264 FileName = stripDirPrefix(FileName, StripLevel);
265 return getPGOFuncName(F.getName(), F.getLinkage(), FileName, Version);
266 }
267
268 // In LTO mode (when InLTO is true), first check if there is a meta data.
269 if (MDNode *MD = getPGOFuncNameMetadata(F)) {
270 StringRef S = cast<MDString>(MD->getOperand(0))->getString();
271 return S.str();
272 }
273
274 // If there is no meta data, the function must be a global before the value
275 // profile annotation pass. Its current linkage may be internal if it is
276 // internalized in LTO mode.
277 return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
278 }
279
getFuncNameWithoutPrefix(StringRef PGOFuncName,StringRef FileName)280 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
281 if (FileName.empty())
282 return PGOFuncName;
283 // Drop the file name including ':'. See also getPGOFuncName.
284 if (PGOFuncName.startswith(FileName))
285 PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
286 return PGOFuncName;
287 }
288
289 // \p FuncName is the string used as profile lookup key for the function. A
290 // symbol is created to hold the name. Return the legalized symbol name.
getPGOFuncNameVarName(StringRef FuncName,GlobalValue::LinkageTypes Linkage)291 std::string getPGOFuncNameVarName(StringRef FuncName,
292 GlobalValue::LinkageTypes Linkage) {
293 std::string VarName = std::string(getInstrProfNameVarPrefix());
294 VarName += FuncName;
295
296 if (!GlobalValue::isLocalLinkage(Linkage))
297 return VarName;
298
299 // Now fix up illegal chars in local VarName that may upset the assembler.
300 const char *InvalidChars = "-:<>/\"'";
301 size_t found = VarName.find_first_of(InvalidChars);
302 while (found != std::string::npos) {
303 VarName[found] = '_';
304 found = VarName.find_first_of(InvalidChars, found + 1);
305 }
306 return VarName;
307 }
308
createPGOFuncNameVar(Module & M,GlobalValue::LinkageTypes Linkage,StringRef PGOFuncName)309 GlobalVariable *createPGOFuncNameVar(Module &M,
310 GlobalValue::LinkageTypes Linkage,
311 StringRef PGOFuncName) {
312 // We generally want to match the function's linkage, but available_externally
313 // and extern_weak both have the wrong semantics, and anything that doesn't
314 // need to link across compilation units doesn't need to be visible at all.
315 if (Linkage == GlobalValue::ExternalWeakLinkage)
316 Linkage = GlobalValue::LinkOnceAnyLinkage;
317 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
318 Linkage = GlobalValue::LinkOnceODRLinkage;
319 else if (Linkage == GlobalValue::InternalLinkage ||
320 Linkage == GlobalValue::ExternalLinkage)
321 Linkage = GlobalValue::PrivateLinkage;
322
323 auto *Value =
324 ConstantDataArray::getString(M.getContext(), PGOFuncName, false);
325 auto FuncNameVar =
326 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
327 getPGOFuncNameVarName(PGOFuncName, Linkage));
328
329 // Hide the symbol so that we correctly get a copy for each executable.
330 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
331 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
332
333 return FuncNameVar;
334 }
335
createPGOFuncNameVar(Function & F,StringRef PGOFuncName)336 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName) {
337 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), PGOFuncName);
338 }
339
create(Module & M,bool InLTO)340 Error InstrProfSymtab::create(Module &M, bool InLTO) {
341 for (Function &F : M) {
342 // Function may not have a name: like using asm("") to overwrite the name.
343 // Ignore in this case.
344 if (!F.hasName())
345 continue;
346 const std::string &PGOFuncName = getPGOFuncName(F, InLTO);
347 if (Error E = addFuncName(PGOFuncName))
348 return E;
349 MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
350 // In ThinLTO, local function may have been promoted to global and have
351 // suffix added to the function name. We need to add the stripped function
352 // name to the symbol table so that we can find a match from profile.
353 if (InLTO) {
354 auto pos = PGOFuncName.find('.');
355 if (pos != std::string::npos) {
356 const std::string &OtherFuncName = PGOFuncName.substr(0, pos);
357 if (Error E = addFuncName(OtherFuncName))
358 return E;
359 MD5FuncMap.emplace_back(Function::getGUID(OtherFuncName), &F);
360 }
361 }
362 }
363 Sorted = false;
364 finalizeSymtab();
365 return Error::success();
366 }
367
getFunctionHashFromAddress(uint64_t Address)368 uint64_t InstrProfSymtab::getFunctionHashFromAddress(uint64_t Address) {
369 finalizeSymtab();
370 auto It = partition_point(AddrToMD5Map, [=](std::pair<uint64_t, uint64_t> A) {
371 return A.first < Address;
372 });
373 // Raw function pointer collected by value profiler may be from
374 // external functions that are not instrumented. They won't have
375 // mapping data to be used by the deserializer. Force the value to
376 // be 0 in this case.
377 if (It != AddrToMD5Map.end() && It->first == Address)
378 return (uint64_t)It->second;
379 return 0;
380 }
381
collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,bool doCompression,std::string & Result)382 Error collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,
383 bool doCompression, std::string &Result) {
384 assert(!NameStrs.empty() && "No name data to emit");
385
386 uint8_t Header[16], *P = Header;
387 std::string UncompressedNameStrings =
388 join(NameStrs.begin(), NameStrs.end(), getInstrProfNameSeparator());
389
390 assert(StringRef(UncompressedNameStrings)
391 .count(getInstrProfNameSeparator()) == (NameStrs.size() - 1) &&
392 "PGO name is invalid (contains separator token)");
393
394 unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
395 P += EncLen;
396
397 auto WriteStringToResult = [&](size_t CompressedLen, StringRef InputStr) {
398 EncLen = encodeULEB128(CompressedLen, P);
399 P += EncLen;
400 char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
401 unsigned HeaderLen = P - &Header[0];
402 Result.append(HeaderStr, HeaderLen);
403 Result += InputStr;
404 return Error::success();
405 };
406
407 if (!doCompression) {
408 return WriteStringToResult(0, UncompressedNameStrings);
409 }
410
411 SmallString<128> CompressedNameStrings;
412 Error E = zlib::compress(StringRef(UncompressedNameStrings),
413 CompressedNameStrings, zlib::BestSizeCompression);
414 if (E) {
415 consumeError(std::move(E));
416 return make_error<InstrProfError>(instrprof_error::compress_failed);
417 }
418
419 return WriteStringToResult(CompressedNameStrings.size(),
420 CompressedNameStrings);
421 }
422
getPGOFuncNameVarInitializer(GlobalVariable * NameVar)423 StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar) {
424 auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
425 StringRef NameStr =
426 Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
427 return NameStr;
428 }
429
collectPGOFuncNameStrings(ArrayRef<GlobalVariable * > NameVars,std::string & Result,bool doCompression)430 Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
431 std::string &Result, bool doCompression) {
432 std::vector<std::string> NameStrs;
433 for (auto *NameVar : NameVars) {
434 NameStrs.push_back(std::string(getPGOFuncNameVarInitializer(NameVar)));
435 }
436 return collectPGOFuncNameStrings(
437 NameStrs, zlib::isAvailable() && doCompression, Result);
438 }
439
readPGOFuncNameStrings(StringRef NameStrings,InstrProfSymtab & Symtab)440 Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
441 const uint8_t *P = NameStrings.bytes_begin();
442 const uint8_t *EndP = NameStrings.bytes_end();
443 while (P < EndP) {
444 uint32_t N;
445 uint64_t UncompressedSize = decodeULEB128(P, &N);
446 P += N;
447 uint64_t CompressedSize = decodeULEB128(P, &N);
448 P += N;
449 bool isCompressed = (CompressedSize != 0);
450 SmallString<128> UncompressedNameStrings;
451 StringRef NameStrings;
452 if (isCompressed) {
453 if (!llvm::zlib::isAvailable())
454 return make_error<InstrProfError>(instrprof_error::zlib_unavailable);
455
456 StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
457 CompressedSize);
458 if (Error E =
459 zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
460 UncompressedSize)) {
461 consumeError(std::move(E));
462 return make_error<InstrProfError>(instrprof_error::uncompress_failed);
463 }
464 P += CompressedSize;
465 NameStrings = StringRef(UncompressedNameStrings.data(),
466 UncompressedNameStrings.size());
467 } else {
468 NameStrings =
469 StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
470 P += UncompressedSize;
471 }
472 // Now parse the name strings.
473 SmallVector<StringRef, 0> Names;
474 NameStrings.split(Names, getInstrProfNameSeparator());
475 for (StringRef &Name : Names)
476 if (Error E = Symtab.addFuncName(Name))
477 return E;
478
479 while (P < EndP && *P == 0)
480 P++;
481 }
482 return Error::success();
483 }
484
accumulateCounts(CountSumOrPercent & Sum) const485 void InstrProfRecord::accumulateCounts(CountSumOrPercent &Sum) const {
486 uint64_t FuncSum = 0;
487 Sum.NumEntries += Counts.size();
488 for (size_t F = 0, E = Counts.size(); F < E; ++F)
489 FuncSum += Counts[F];
490 Sum.CountSum += FuncSum;
491
492 for (uint32_t VK = IPVK_First; VK <= IPVK_Last; ++VK) {
493 uint64_t KindSum = 0;
494 uint32_t NumValueSites = getNumValueSites(VK);
495 for (size_t I = 0; I < NumValueSites; ++I) {
496 uint32_t NV = getNumValueDataForSite(VK, I);
497 std::unique_ptr<InstrProfValueData[]> VD = getValueForSite(VK, I);
498 for (uint32_t V = 0; V < NV; V++)
499 KindSum += VD[V].Count;
500 }
501 Sum.ValueCounts[VK] += KindSum;
502 }
503 }
504
overlap(InstrProfValueSiteRecord & Input,uint32_t ValueKind,OverlapStats & Overlap,OverlapStats & FuncLevelOverlap)505 void InstrProfValueSiteRecord::overlap(InstrProfValueSiteRecord &Input,
506 uint32_t ValueKind,
507 OverlapStats &Overlap,
508 OverlapStats &FuncLevelOverlap) {
509 this->sortByTargetValues();
510 Input.sortByTargetValues();
511 double Score = 0.0f, FuncLevelScore = 0.0f;
512 auto I = ValueData.begin();
513 auto IE = ValueData.end();
514 auto J = Input.ValueData.begin();
515 auto JE = Input.ValueData.end();
516 while (I != IE && J != JE) {
517 if (I->Value == J->Value) {
518 Score += OverlapStats::score(I->Count, J->Count,
519 Overlap.Base.ValueCounts[ValueKind],
520 Overlap.Test.ValueCounts[ValueKind]);
521 FuncLevelScore += OverlapStats::score(
522 I->Count, J->Count, FuncLevelOverlap.Base.ValueCounts[ValueKind],
523 FuncLevelOverlap.Test.ValueCounts[ValueKind]);
524 ++I;
525 } else if (I->Value < J->Value) {
526 ++I;
527 continue;
528 }
529 ++J;
530 }
531 Overlap.Overlap.ValueCounts[ValueKind] += Score;
532 FuncLevelOverlap.Overlap.ValueCounts[ValueKind] += FuncLevelScore;
533 }
534
535 // Return false on mismatch.
overlapValueProfData(uint32_t ValueKind,InstrProfRecord & Other,OverlapStats & Overlap,OverlapStats & FuncLevelOverlap)536 void InstrProfRecord::overlapValueProfData(uint32_t ValueKind,
537 InstrProfRecord &Other,
538 OverlapStats &Overlap,
539 OverlapStats &FuncLevelOverlap) {
540 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
541 assert(ThisNumValueSites == Other.getNumValueSites(ValueKind));
542 if (!ThisNumValueSites)
543 return;
544
545 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
546 getOrCreateValueSitesForKind(ValueKind);
547 MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
548 Other.getValueSitesForKind(ValueKind);
549 for (uint32_t I = 0; I < ThisNumValueSites; I++)
550 ThisSiteRecords[I].overlap(OtherSiteRecords[I], ValueKind, Overlap,
551 FuncLevelOverlap);
552 }
553
overlap(InstrProfRecord & Other,OverlapStats & Overlap,OverlapStats & FuncLevelOverlap,uint64_t ValueCutoff)554 void InstrProfRecord::overlap(InstrProfRecord &Other, OverlapStats &Overlap,
555 OverlapStats &FuncLevelOverlap,
556 uint64_t ValueCutoff) {
557 // FuncLevel CountSum for other should already computed and nonzero.
558 assert(FuncLevelOverlap.Test.CountSum >= 1.0f);
559 accumulateCounts(FuncLevelOverlap.Base);
560 bool Mismatch = (Counts.size() != Other.Counts.size());
561
562 // Check if the value profiles mismatch.
563 if (!Mismatch) {
564 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind) {
565 uint32_t ThisNumValueSites = getNumValueSites(Kind);
566 uint32_t OtherNumValueSites = Other.getNumValueSites(Kind);
567 if (ThisNumValueSites != OtherNumValueSites) {
568 Mismatch = true;
569 break;
570 }
571 }
572 }
573 if (Mismatch) {
574 Overlap.addOneMismatch(FuncLevelOverlap.Test);
575 return;
576 }
577
578 // Compute overlap for value counts.
579 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
580 overlapValueProfData(Kind, Other, Overlap, FuncLevelOverlap);
581
582 double Score = 0.0;
583 uint64_t MaxCount = 0;
584 // Compute overlap for edge counts.
585 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
586 Score += OverlapStats::score(Counts[I], Other.Counts[I],
587 Overlap.Base.CountSum, Overlap.Test.CountSum);
588 MaxCount = std::max(Other.Counts[I], MaxCount);
589 }
590 Overlap.Overlap.CountSum += Score;
591 Overlap.Overlap.NumEntries += 1;
592
593 if (MaxCount >= ValueCutoff) {
594 double FuncScore = 0.0;
595 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I)
596 FuncScore += OverlapStats::score(Counts[I], Other.Counts[I],
597 FuncLevelOverlap.Base.CountSum,
598 FuncLevelOverlap.Test.CountSum);
599 FuncLevelOverlap.Overlap.CountSum = FuncScore;
600 FuncLevelOverlap.Overlap.NumEntries = Other.Counts.size();
601 FuncLevelOverlap.Valid = true;
602 }
603 }
604
merge(InstrProfValueSiteRecord & Input,uint64_t Weight,function_ref<void (instrprof_error)> Warn)605 void InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
606 uint64_t Weight,
607 function_ref<void(instrprof_error)> Warn) {
608 this->sortByTargetValues();
609 Input.sortByTargetValues();
610 auto I = ValueData.begin();
611 auto IE = ValueData.end();
612 for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
613 ++J) {
614 while (I != IE && I->Value < J->Value)
615 ++I;
616 if (I != IE && I->Value == J->Value) {
617 bool Overflowed;
618 I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
619 if (Overflowed)
620 Warn(instrprof_error::counter_overflow);
621 ++I;
622 continue;
623 }
624 ValueData.insert(I, *J);
625 }
626 }
627
scale(uint64_t N,uint64_t D,function_ref<void (instrprof_error)> Warn)628 void InstrProfValueSiteRecord::scale(uint64_t N, uint64_t D,
629 function_ref<void(instrprof_error)> Warn) {
630 for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
631 bool Overflowed;
632 I->Count = SaturatingMultiply(I->Count, N, &Overflowed) / D;
633 if (Overflowed)
634 Warn(instrprof_error::counter_overflow);
635 }
636 }
637
638 // Merge Value Profile data from Src record to this record for ValueKind.
639 // Scale merged value counts by \p Weight.
mergeValueProfData(uint32_t ValueKind,InstrProfRecord & Src,uint64_t Weight,function_ref<void (instrprof_error)> Warn)640 void InstrProfRecord::mergeValueProfData(
641 uint32_t ValueKind, InstrProfRecord &Src, uint64_t Weight,
642 function_ref<void(instrprof_error)> Warn) {
643 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
644 uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
645 if (ThisNumValueSites != OtherNumValueSites) {
646 Warn(instrprof_error::value_site_count_mismatch);
647 return;
648 }
649 if (!ThisNumValueSites)
650 return;
651 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
652 getOrCreateValueSitesForKind(ValueKind);
653 MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
654 Src.getValueSitesForKind(ValueKind);
655 for (uint32_t I = 0; I < ThisNumValueSites; I++)
656 ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight, Warn);
657 }
658
merge(InstrProfRecord & Other,uint64_t Weight,function_ref<void (instrprof_error)> Warn)659 void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
660 function_ref<void(instrprof_error)> Warn) {
661 // If the number of counters doesn't match we either have bad data
662 // or a hash collision.
663 if (Counts.size() != Other.Counts.size()) {
664 Warn(instrprof_error::count_mismatch);
665 return;
666 }
667
668 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
669 bool Overflowed;
670 Counts[I] =
671 SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
672 if (Overflowed)
673 Warn(instrprof_error::counter_overflow);
674 }
675
676 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
677 mergeValueProfData(Kind, Other, Weight, Warn);
678 }
679
scaleValueProfData(uint32_t ValueKind,uint64_t N,uint64_t D,function_ref<void (instrprof_error)> Warn)680 void InstrProfRecord::scaleValueProfData(
681 uint32_t ValueKind, uint64_t N, uint64_t D,
682 function_ref<void(instrprof_error)> Warn) {
683 for (auto &R : getValueSitesForKind(ValueKind))
684 R.scale(N, D, Warn);
685 }
686
scale(uint64_t N,uint64_t D,function_ref<void (instrprof_error)> Warn)687 void InstrProfRecord::scale(uint64_t N, uint64_t D,
688 function_ref<void(instrprof_error)> Warn) {
689 assert(D != 0 && "D cannot be 0");
690 for (auto &Count : this->Counts) {
691 bool Overflowed;
692 Count = SaturatingMultiply(Count, N, &Overflowed) / D;
693 if (Overflowed)
694 Warn(instrprof_error::counter_overflow);
695 }
696 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
697 scaleValueProfData(Kind, N, D, Warn);
698 }
699
700 // Map indirect call target name hash to name string.
remapValue(uint64_t Value,uint32_t ValueKind,InstrProfSymtab * SymTab)701 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
702 InstrProfSymtab *SymTab) {
703 if (!SymTab)
704 return Value;
705
706 if (ValueKind == IPVK_IndirectCallTarget)
707 return SymTab->getFunctionHashFromAddress(Value);
708
709 return Value;
710 }
711
addValueData(uint32_t ValueKind,uint32_t Site,InstrProfValueData * VData,uint32_t N,InstrProfSymtab * ValueMap)712 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
713 InstrProfValueData *VData, uint32_t N,
714 InstrProfSymtab *ValueMap) {
715 for (uint32_t I = 0; I < N; I++) {
716 VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
717 }
718 std::vector<InstrProfValueSiteRecord> &ValueSites =
719 getOrCreateValueSitesForKind(ValueKind);
720 if (N == 0)
721 ValueSites.emplace_back();
722 else
723 ValueSites.emplace_back(VData, VData + N);
724 }
725
726 #define INSTR_PROF_COMMON_API_IMPL
727 #include "llvm/ProfileData/InstrProfData.inc"
728
729 /*!
730 * ValueProfRecordClosure Interface implementation for InstrProfRecord
731 * class. These C wrappers are used as adaptors so that C++ code can be
732 * invoked as callbacks.
733 */
getNumValueKindsInstrProf(const void * Record)734 uint32_t getNumValueKindsInstrProf(const void *Record) {
735 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
736 }
737
getNumValueSitesInstrProf(const void * Record,uint32_t VKind)738 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
739 return reinterpret_cast<const InstrProfRecord *>(Record)
740 ->getNumValueSites(VKind);
741 }
742
getNumValueDataInstrProf(const void * Record,uint32_t VKind)743 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
744 return reinterpret_cast<const InstrProfRecord *>(Record)
745 ->getNumValueData(VKind);
746 }
747
getNumValueDataForSiteInstrProf(const void * R,uint32_t VK,uint32_t S)748 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
749 uint32_t S) {
750 return reinterpret_cast<const InstrProfRecord *>(R)
751 ->getNumValueDataForSite(VK, S);
752 }
753
getValueForSiteInstrProf(const void * R,InstrProfValueData * Dst,uint32_t K,uint32_t S)754 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
755 uint32_t K, uint32_t S) {
756 reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(Dst, K, S);
757 }
758
allocValueProfDataInstrProf(size_t TotalSizeInBytes)759 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
760 ValueProfData *VD =
761 (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
762 memset(VD, 0, TotalSizeInBytes);
763 return VD;
764 }
765
766 static ValueProfRecordClosure InstrProfRecordClosure = {
767 nullptr,
768 getNumValueKindsInstrProf,
769 getNumValueSitesInstrProf,
770 getNumValueDataInstrProf,
771 getNumValueDataForSiteInstrProf,
772 nullptr,
773 getValueForSiteInstrProf,
774 allocValueProfDataInstrProf};
775
776 // Wrapper implementation using the closure mechanism.
getSize(const InstrProfRecord & Record)777 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
778 auto Closure = InstrProfRecordClosure;
779 Closure.Record = &Record;
780 return getValueProfDataSize(&Closure);
781 }
782
783 // Wrapper implementation using the closure mechanism.
784 std::unique_ptr<ValueProfData>
serializeFrom(const InstrProfRecord & Record)785 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
786 InstrProfRecordClosure.Record = &Record;
787
788 std::unique_ptr<ValueProfData> VPD(
789 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
790 return VPD;
791 }
792
deserializeTo(InstrProfRecord & Record,InstrProfSymtab * SymTab)793 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
794 InstrProfSymtab *SymTab) {
795 Record.reserveSites(Kind, NumValueSites);
796
797 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
798 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
799 uint8_t ValueDataCount = this->SiteCountArray[VSite];
800 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, SymTab);
801 ValueData += ValueDataCount;
802 }
803 }
804
805 // For writing/serializing, Old is the host endianness, and New is
806 // byte order intended on disk. For Reading/deserialization, Old
807 // is the on-disk source endianness, and New is the host endianness.
swapBytes(support::endianness Old,support::endianness New)808 void ValueProfRecord::swapBytes(support::endianness Old,
809 support::endianness New) {
810 using namespace support;
811
812 if (Old == New)
813 return;
814
815 if (getHostEndianness() != Old) {
816 sys::swapByteOrder<uint32_t>(NumValueSites);
817 sys::swapByteOrder<uint32_t>(Kind);
818 }
819 uint32_t ND = getValueProfRecordNumValueData(this);
820 InstrProfValueData *VD = getValueProfRecordValueData(this);
821
822 // No need to swap byte array: SiteCountArrray.
823 for (uint32_t I = 0; I < ND; I++) {
824 sys::swapByteOrder<uint64_t>(VD[I].Value);
825 sys::swapByteOrder<uint64_t>(VD[I].Count);
826 }
827 if (getHostEndianness() == Old) {
828 sys::swapByteOrder<uint32_t>(NumValueSites);
829 sys::swapByteOrder<uint32_t>(Kind);
830 }
831 }
832
deserializeTo(InstrProfRecord & Record,InstrProfSymtab * SymTab)833 void ValueProfData::deserializeTo(InstrProfRecord &Record,
834 InstrProfSymtab *SymTab) {
835 if (NumValueKinds == 0)
836 return;
837
838 ValueProfRecord *VR = getFirstValueProfRecord(this);
839 for (uint32_t K = 0; K < NumValueKinds; K++) {
840 VR->deserializeTo(Record, SymTab);
841 VR = getValueProfRecordNext(VR);
842 }
843 }
844
845 template <class T>
swapToHostOrder(const unsigned char * & D,support::endianness Orig)846 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
847 using namespace support;
848
849 if (Orig == little)
850 return endian::readNext<T, little, unaligned>(D);
851 else
852 return endian::readNext<T, big, unaligned>(D);
853 }
854
allocValueProfData(uint32_t TotalSize)855 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
856 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
857 ValueProfData());
858 }
859
checkIntegrity()860 Error ValueProfData::checkIntegrity() {
861 if (NumValueKinds > IPVK_Last + 1)
862 return make_error<InstrProfError>(instrprof_error::malformed);
863 // Total size needs to be mulltiple of quadword size.
864 if (TotalSize % sizeof(uint64_t))
865 return make_error<InstrProfError>(instrprof_error::malformed);
866
867 ValueProfRecord *VR = getFirstValueProfRecord(this);
868 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
869 if (VR->Kind > IPVK_Last)
870 return make_error<InstrProfError>(instrprof_error::malformed);
871 VR = getValueProfRecordNext(VR);
872 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
873 return make_error<InstrProfError>(instrprof_error::malformed);
874 }
875 return Error::success();
876 }
877
878 Expected<std::unique_ptr<ValueProfData>>
getValueProfData(const unsigned char * D,const unsigned char * const BufferEnd,support::endianness Endianness)879 ValueProfData::getValueProfData(const unsigned char *D,
880 const unsigned char *const BufferEnd,
881 support::endianness Endianness) {
882 using namespace support;
883
884 if (D + sizeof(ValueProfData) > BufferEnd)
885 return make_error<InstrProfError>(instrprof_error::truncated);
886
887 const unsigned char *Header = D;
888 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
889 if (D + TotalSize > BufferEnd)
890 return make_error<InstrProfError>(instrprof_error::too_large);
891
892 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
893 memcpy(VPD.get(), D, TotalSize);
894 // Byte swap.
895 VPD->swapBytesToHost(Endianness);
896
897 Error E = VPD->checkIntegrity();
898 if (E)
899 return std::move(E);
900
901 return std::move(VPD);
902 }
903
swapBytesToHost(support::endianness Endianness)904 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
905 using namespace support;
906
907 if (Endianness == getHostEndianness())
908 return;
909
910 sys::swapByteOrder<uint32_t>(TotalSize);
911 sys::swapByteOrder<uint32_t>(NumValueKinds);
912
913 ValueProfRecord *VR = getFirstValueProfRecord(this);
914 for (uint32_t K = 0; K < NumValueKinds; K++) {
915 VR->swapBytes(Endianness, getHostEndianness());
916 VR = getValueProfRecordNext(VR);
917 }
918 }
919
swapBytesFromHost(support::endianness Endianness)920 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
921 using namespace support;
922
923 if (Endianness == getHostEndianness())
924 return;
925
926 ValueProfRecord *VR = getFirstValueProfRecord(this);
927 for (uint32_t K = 0; K < NumValueKinds; K++) {
928 ValueProfRecord *NVR = getValueProfRecordNext(VR);
929 VR->swapBytes(getHostEndianness(), Endianness);
930 VR = NVR;
931 }
932 sys::swapByteOrder<uint32_t>(TotalSize);
933 sys::swapByteOrder<uint32_t>(NumValueKinds);
934 }
935
annotateValueSite(Module & M,Instruction & Inst,const InstrProfRecord & InstrProfR,InstrProfValueKind ValueKind,uint32_t SiteIdx,uint32_t MaxMDCount)936 void annotateValueSite(Module &M, Instruction &Inst,
937 const InstrProfRecord &InstrProfR,
938 InstrProfValueKind ValueKind, uint32_t SiteIdx,
939 uint32_t MaxMDCount) {
940 uint32_t NV = InstrProfR.getNumValueDataForSite(ValueKind, SiteIdx);
941 if (!NV)
942 return;
943
944 uint64_t Sum = 0;
945 std::unique_ptr<InstrProfValueData[]> VD =
946 InstrProfR.getValueForSite(ValueKind, SiteIdx, &Sum);
947
948 ArrayRef<InstrProfValueData> VDs(VD.get(), NV);
949 annotateValueSite(M, Inst, VDs, Sum, ValueKind, MaxMDCount);
950 }
951
annotateValueSite(Module & M,Instruction & Inst,ArrayRef<InstrProfValueData> VDs,uint64_t Sum,InstrProfValueKind ValueKind,uint32_t MaxMDCount)952 void annotateValueSite(Module &M, Instruction &Inst,
953 ArrayRef<InstrProfValueData> VDs,
954 uint64_t Sum, InstrProfValueKind ValueKind,
955 uint32_t MaxMDCount) {
956 LLVMContext &Ctx = M.getContext();
957 MDBuilder MDHelper(Ctx);
958 SmallVector<Metadata *, 3> Vals;
959 // Tag
960 Vals.push_back(MDHelper.createString("VP"));
961 // Value Kind
962 Vals.push_back(MDHelper.createConstant(
963 ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
964 // Total Count
965 Vals.push_back(
966 MDHelper.createConstant(ConstantInt::get(Type::getInt64Ty(Ctx), Sum)));
967
968 // Value Profile Data
969 uint32_t MDCount = MaxMDCount;
970 for (auto &VD : VDs) {
971 Vals.push_back(MDHelper.createConstant(
972 ConstantInt::get(Type::getInt64Ty(Ctx), VD.Value)));
973 Vals.push_back(MDHelper.createConstant(
974 ConstantInt::get(Type::getInt64Ty(Ctx), VD.Count)));
975 if (--MDCount == 0)
976 break;
977 }
978 Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
979 }
980
getValueProfDataFromInst(const Instruction & Inst,InstrProfValueKind ValueKind,uint32_t MaxNumValueData,InstrProfValueData ValueData[],uint32_t & ActualNumValueData,uint64_t & TotalC)981 bool getValueProfDataFromInst(const Instruction &Inst,
982 InstrProfValueKind ValueKind,
983 uint32_t MaxNumValueData,
984 InstrProfValueData ValueData[],
985 uint32_t &ActualNumValueData, uint64_t &TotalC) {
986 MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
987 if (!MD)
988 return false;
989
990 unsigned NOps = MD->getNumOperands();
991
992 if (NOps < 5)
993 return false;
994
995 // Operand 0 is a string tag "VP":
996 MDString *Tag = cast<MDString>(MD->getOperand(0));
997 if (!Tag)
998 return false;
999
1000 if (!Tag->getString().equals("VP"))
1001 return false;
1002
1003 // Now check kind:
1004 ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
1005 if (!KindInt)
1006 return false;
1007 if (KindInt->getZExtValue() != ValueKind)
1008 return false;
1009
1010 // Get total count
1011 ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
1012 if (!TotalCInt)
1013 return false;
1014 TotalC = TotalCInt->getZExtValue();
1015
1016 ActualNumValueData = 0;
1017
1018 for (unsigned I = 3; I < NOps; I += 2) {
1019 if (ActualNumValueData >= MaxNumValueData)
1020 break;
1021 ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
1022 ConstantInt *Count =
1023 mdconst::dyn_extract<ConstantInt>(MD->getOperand(I + 1));
1024 if (!Value || !Count)
1025 return false;
1026 ValueData[ActualNumValueData].Value = Value->getZExtValue();
1027 ValueData[ActualNumValueData].Count = Count->getZExtValue();
1028 ActualNumValueData++;
1029 }
1030 return true;
1031 }
1032
getPGOFuncNameMetadata(const Function & F)1033 MDNode *getPGOFuncNameMetadata(const Function &F) {
1034 return F.getMetadata(getPGOFuncNameMetadataName());
1035 }
1036
createPGOFuncNameMetadata(Function & F,StringRef PGOFuncName)1037 void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
1038 // Only for internal linkage functions.
1039 if (PGOFuncName == F.getName())
1040 return;
1041 // Don't create duplicated meta-data.
1042 if (getPGOFuncNameMetadata(F))
1043 return;
1044 LLVMContext &C = F.getContext();
1045 MDNode *N = MDNode::get(C, MDString::get(C, PGOFuncName));
1046 F.setMetadata(getPGOFuncNameMetadataName(), N);
1047 }
1048
needsComdatForCounter(const Function & F,const Module & M)1049 bool needsComdatForCounter(const Function &F, const Module &M) {
1050 if (F.hasComdat())
1051 return true;
1052
1053 if (!Triple(M.getTargetTriple()).supportsCOMDAT())
1054 return false;
1055
1056 // See createPGOFuncNameVar for more details. To avoid link errors, profile
1057 // counters for function with available_externally linkage needs to be changed
1058 // to linkonce linkage. On ELF based systems, this leads to weak symbols to be
1059 // created. Without using comdat, duplicate entries won't be removed by the
1060 // linker leading to increased data segement size and raw profile size. Even
1061 // worse, since the referenced counter from profile per-function data object
1062 // will be resolved to the common strong definition, the profile counts for
1063 // available_externally functions will end up being duplicated in raw profile
1064 // data. This can result in distorted profile as the counts of those dups
1065 // will be accumulated by the profile merger.
1066 GlobalValue::LinkageTypes Linkage = F.getLinkage();
1067 if (Linkage != GlobalValue::ExternalWeakLinkage &&
1068 Linkage != GlobalValue::AvailableExternallyLinkage)
1069 return false;
1070
1071 return true;
1072 }
1073
1074 // Check if INSTR_PROF_RAW_VERSION_VAR is defined.
isIRPGOFlagSet(const Module * M)1075 bool isIRPGOFlagSet(const Module *M) {
1076 auto IRInstrVar =
1077 M->getNamedGlobal(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
1078 if (!IRInstrVar || IRInstrVar->isDeclaration() ||
1079 IRInstrVar->hasLocalLinkage())
1080 return false;
1081
1082 // Check if the flag is set.
1083 if (!IRInstrVar->hasInitializer())
1084 return false;
1085
1086 auto *InitVal = dyn_cast_or_null<ConstantInt>(IRInstrVar->getInitializer());
1087 if (!InitVal)
1088 return false;
1089 return (InitVal->getZExtValue() & VARIANT_MASK_IR_PROF) != 0;
1090 }
1091
1092 // Check if we can safely rename this Comdat function.
canRenameComdatFunc(const Function & F,bool CheckAddressTaken)1093 bool canRenameComdatFunc(const Function &F, bool CheckAddressTaken) {
1094 if (F.getName().empty())
1095 return false;
1096 if (!needsComdatForCounter(F, *(F.getParent())))
1097 return false;
1098 // Unsafe to rename the address-taken function (which can be used in
1099 // function comparison).
1100 if (CheckAddressTaken && F.hasAddressTaken())
1101 return false;
1102 // Only safe to do if this function may be discarded if it is not used
1103 // in the compilation unit.
1104 if (!GlobalValue::isDiscardableIfUnused(F.getLinkage()))
1105 return false;
1106
1107 // For AvailableExternallyLinkage functions.
1108 if (!F.hasComdat()) {
1109 assert(F.getLinkage() == GlobalValue::AvailableExternallyLinkage);
1110 return true;
1111 }
1112 return true;
1113 }
1114
1115 // Create a COMDAT variable INSTR_PROF_RAW_VERSION_VAR to make the runtime
1116 // aware this is an ir_level profile so it can set the version flag.
createIRLevelProfileFlagVar(Module & M,bool IsCS,bool InstrEntryBBEnabled)1117 void createIRLevelProfileFlagVar(Module &M, bool IsCS,
1118 bool InstrEntryBBEnabled) {
1119 const StringRef VarName(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
1120 Type *IntTy64 = Type::getInt64Ty(M.getContext());
1121 uint64_t ProfileVersion = (INSTR_PROF_RAW_VERSION | VARIANT_MASK_IR_PROF);
1122 if (IsCS)
1123 ProfileVersion |= VARIANT_MASK_CSIR_PROF;
1124 if (InstrEntryBBEnabled)
1125 ProfileVersion |= VARIANT_MASK_INSTR_ENTRY;
1126 auto IRLevelVersionVariable = new GlobalVariable(
1127 M, IntTy64, true, GlobalValue::WeakAnyLinkage,
1128 Constant::getIntegerValue(IntTy64, APInt(64, ProfileVersion)), VarName);
1129 IRLevelVersionVariable->setVisibility(GlobalValue::DefaultVisibility);
1130 Triple TT(M.getTargetTriple());
1131 if (TT.supportsCOMDAT()) {
1132 IRLevelVersionVariable->setLinkage(GlobalValue::ExternalLinkage);
1133 IRLevelVersionVariable->setComdat(M.getOrInsertComdat(VarName));
1134 }
1135 }
1136
1137 // Create the variable for the profile file name.
createProfileFileNameVar(Module & M,StringRef InstrProfileOutput)1138 void createProfileFileNameVar(Module &M, StringRef InstrProfileOutput) {
1139 if (InstrProfileOutput.empty())
1140 return;
1141 Constant *ProfileNameConst =
1142 ConstantDataArray::getString(M.getContext(), InstrProfileOutput, true);
1143 GlobalVariable *ProfileNameVar = new GlobalVariable(
1144 M, ProfileNameConst->getType(), true, GlobalValue::WeakAnyLinkage,
1145 ProfileNameConst, INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR));
1146 Triple TT(M.getTargetTriple());
1147 if (TT.supportsCOMDAT()) {
1148 ProfileNameVar->setLinkage(GlobalValue::ExternalLinkage);
1149 ProfileNameVar->setComdat(M.getOrInsertComdat(
1150 StringRef(INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR))));
1151 }
1152 }
1153
accumulateCounts(const std::string & BaseFilename,const std::string & TestFilename,bool IsCS)1154 Error OverlapStats::accumulateCounts(const std::string &BaseFilename,
1155 const std::string &TestFilename,
1156 bool IsCS) {
1157 auto getProfileSum = [IsCS](const std::string &Filename,
1158 CountSumOrPercent &Sum) -> Error {
1159 auto ReaderOrErr = InstrProfReader::create(Filename);
1160 if (Error E = ReaderOrErr.takeError()) {
1161 return E;
1162 }
1163 auto Reader = std::move(ReaderOrErr.get());
1164 Reader->accumulateCounts(Sum, IsCS);
1165 return Error::success();
1166 };
1167 auto Ret = getProfileSum(BaseFilename, Base);
1168 if (Ret)
1169 return Ret;
1170 Ret = getProfileSum(TestFilename, Test);
1171 if (Ret)
1172 return Ret;
1173 this->BaseFilename = &BaseFilename;
1174 this->TestFilename = &TestFilename;
1175 Valid = true;
1176 return Error::success();
1177 }
1178
addOneMismatch(const CountSumOrPercent & MismatchFunc)1179 void OverlapStats::addOneMismatch(const CountSumOrPercent &MismatchFunc) {
1180 Mismatch.NumEntries += 1;
1181 Mismatch.CountSum += MismatchFunc.CountSum / Test.CountSum;
1182 for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1183 if (Test.ValueCounts[I] >= 1.0f)
1184 Mismatch.ValueCounts[I] +=
1185 MismatchFunc.ValueCounts[I] / Test.ValueCounts[I];
1186 }
1187 }
1188
addOneUnique(const CountSumOrPercent & UniqueFunc)1189 void OverlapStats::addOneUnique(const CountSumOrPercent &UniqueFunc) {
1190 Unique.NumEntries += 1;
1191 Unique.CountSum += UniqueFunc.CountSum / Test.CountSum;
1192 for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1193 if (Test.ValueCounts[I] >= 1.0f)
1194 Unique.ValueCounts[I] += UniqueFunc.ValueCounts[I] / Test.ValueCounts[I];
1195 }
1196 }
1197
dump(raw_fd_ostream & OS) const1198 void OverlapStats::dump(raw_fd_ostream &OS) const {
1199 if (!Valid)
1200 return;
1201
1202 const char *EntryName =
1203 (Level == ProgramLevel ? "functions" : "edge counters");
1204 if (Level == ProgramLevel) {
1205 OS << "Profile overlap infomation for base_profile: " << *BaseFilename
1206 << " and test_profile: " << *TestFilename << "\nProgram level:\n";
1207 } else {
1208 OS << "Function level:\n"
1209 << " Function: " << FuncName << " (Hash=" << FuncHash << ")\n";
1210 }
1211
1212 OS << " # of " << EntryName << " overlap: " << Overlap.NumEntries << "\n";
1213 if (Mismatch.NumEntries)
1214 OS << " # of " << EntryName << " mismatch: " << Mismatch.NumEntries
1215 << "\n";
1216 if (Unique.NumEntries)
1217 OS << " # of " << EntryName
1218 << " only in test_profile: " << Unique.NumEntries << "\n";
1219
1220 OS << " Edge profile overlap: " << format("%.3f%%", Overlap.CountSum * 100)
1221 << "\n";
1222 if (Mismatch.NumEntries)
1223 OS << " Mismatched count percentage (Edge): "
1224 << format("%.3f%%", Mismatch.CountSum * 100) << "\n";
1225 if (Unique.NumEntries)
1226 OS << " Percentage of Edge profile only in test_profile: "
1227 << format("%.3f%%", Unique.CountSum * 100) << "\n";
1228 OS << " Edge profile base count sum: " << format("%.0f", Base.CountSum)
1229 << "\n"
1230 << " Edge profile test count sum: " << format("%.0f", Test.CountSum)
1231 << "\n";
1232
1233 for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1234 if (Base.ValueCounts[I] < 1.0f && Test.ValueCounts[I] < 1.0f)
1235 continue;
1236 char ProfileKindName[20];
1237 switch (I) {
1238 case IPVK_IndirectCallTarget:
1239 strncpy(ProfileKindName, "IndirectCall", 19);
1240 break;
1241 case IPVK_MemOPSize:
1242 strncpy(ProfileKindName, "MemOP", 19);
1243 break;
1244 default:
1245 snprintf(ProfileKindName, 19, "VP[%d]", I);
1246 break;
1247 }
1248 OS << " " << ProfileKindName
1249 << " profile overlap: " << format("%.3f%%", Overlap.ValueCounts[I] * 100)
1250 << "\n";
1251 if (Mismatch.NumEntries)
1252 OS << " Mismatched count percentage (" << ProfileKindName
1253 << "): " << format("%.3f%%", Mismatch.ValueCounts[I] * 100) << "\n";
1254 if (Unique.NumEntries)
1255 OS << " Percentage of " << ProfileKindName
1256 << " profile only in test_profile: "
1257 << format("%.3f%%", Unique.ValueCounts[I] * 100) << "\n";
1258 OS << " " << ProfileKindName
1259 << " profile base count sum: " << format("%.0f", Base.ValueCounts[I])
1260 << "\n"
1261 << " " << ProfileKindName
1262 << " profile test count sum: " << format("%.0f", Test.ValueCounts[I])
1263 << "\n";
1264 }
1265 }
1266
1267 } // end namespace llvm
1268