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/Config/config.h"
22 #include "llvm/IR/Constant.h"
23 #include "llvm/IR/Constants.h"
24 #include "llvm/IR/Function.h"
25 #include "llvm/IR/GlobalValue.h"
26 #include "llvm/IR/GlobalVariable.h"
27 #include "llvm/IR/Instruction.h"
28 #include "llvm/IR/LLVMContext.h"
29 #include "llvm/IR/MDBuilder.h"
30 #include "llvm/IR/Metadata.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IR/Type.h"
33 #include "llvm/ProfileData/InstrProfReader.h"
34 #include "llvm/Support/Casting.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Support/Compression.h"
38 #include "llvm/Support/Endian.h"
39 #include "llvm/Support/Error.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/LEB128.h"
42 #include "llvm/Support/ManagedStatic.h"
43 #include "llvm/Support/MathExtras.h"
44 #include "llvm/Support/Path.h"
45 #include "llvm/Support/SwapByteOrder.h"
46 #include <algorithm>
47 #include <cassert>
48 #include <cstddef>
49 #include <cstdint>
50 #include <cstring>
51 #include <memory>
52 #include <string>
53 #include <system_error>
54 #include <utility>
55 #include <vector>
56
57 using namespace llvm;
58
59 static cl::opt<bool> StaticFuncFullModulePrefix(
60 "static-func-full-module-prefix", cl::init(true), cl::Hidden,
61 cl::desc("Use full module build paths in the profile counter names for "
62 "static functions."));
63
64 // This option is tailored to users that have different top-level directory in
65 // profile-gen and profile-use compilation. Users need to specific the number
66 // of levels to strip. A value larger than the number of directories in the
67 // source file will strip all the directory names and only leave the basename.
68 //
69 // Note current ThinLTO module importing for the indirect-calls assumes
70 // the source directory name not being stripped. A non-zero option value here
71 // can potentially prevent some inter-module indirect-call-promotions.
72 static cl::opt<unsigned> StaticFuncStripDirNamePrefix(
73 "static-func-strip-dirname-prefix", cl::init(0), cl::Hidden,
74 cl::desc("Strip specified level of directory name from source path in "
75 "the profile counter name for static functions."));
76
getInstrProfErrString(instrprof_error Err)77 static std::string getInstrProfErrString(instrprof_error Err) {
78 switch (Err) {
79 case instrprof_error::success:
80 return "Success";
81 case instrprof_error::eof:
82 return "End of File";
83 case instrprof_error::unrecognized_format:
84 return "Unrecognized instrumentation profile encoding format";
85 case instrprof_error::bad_magic:
86 return "Invalid instrumentation profile data (bad magic)";
87 case instrprof_error::bad_header:
88 return "Invalid instrumentation profile data (file header is corrupt)";
89 case instrprof_error::unsupported_version:
90 return "Unsupported instrumentation profile format version";
91 case instrprof_error::unsupported_hash_type:
92 return "Unsupported instrumentation profile hash type";
93 case instrprof_error::too_large:
94 return "Too much profile data";
95 case instrprof_error::truncated:
96 return "Truncated profile data";
97 case instrprof_error::malformed:
98 return "Malformed instrumentation profile data";
99 case instrprof_error::invalid_prof:
100 return "Invalid profile created. Please file a bug "
101 "at: " BUG_REPORT_URL
102 " and include the profraw files that caused this error.";
103 case instrprof_error::unknown_function:
104 return "No profile data available for function";
105 case instrprof_error::hash_mismatch:
106 return "Function control flow change detected (hash mismatch)";
107 case instrprof_error::count_mismatch:
108 return "Function basic block count change detected (counter mismatch)";
109 case instrprof_error::counter_overflow:
110 return "Counter overflow";
111 case instrprof_error::value_site_count_mismatch:
112 return "Function value site count change detected (counter mismatch)";
113 case instrprof_error::compress_failed:
114 return "Failed to compress data (zlib)";
115 case instrprof_error::uncompress_failed:
116 return "Failed to uncompress data (zlib)";
117 case instrprof_error::empty_raw_profile:
118 return "Empty raw profile file";
119 case instrprof_error::zlib_unavailable:
120 return "Profile uses zlib compression but the profile reader was built without zlib support";
121 }
122 llvm_unreachable("A value of instrprof_error has no message.");
123 }
124
125 namespace {
126
127 // FIXME: This class is only here to support the transition to llvm::Error. It
128 // will be removed once this transition is complete. Clients should prefer to
129 // deal with the Error value directly, rather than converting to error_code.
130 class InstrProfErrorCategoryType : public std::error_category {
name() const131 const char *name() const noexcept override { return "llvm.instrprof"; }
132
message(int IE) const133 std::string message(int IE) const override {
134 return getInstrProfErrString(static_cast<instrprof_error>(IE));
135 }
136 };
137
138 } // end anonymous namespace
139
140 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
141
instrprof_category()142 const std::error_category &llvm::instrprof_category() {
143 return *ErrorCategory;
144 }
145
146 namespace {
147
148 const char *InstrProfSectNameCommon[] = {
149 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
150 SectNameCommon,
151 #include "llvm/ProfileData/InstrProfData.inc"
152 };
153
154 const char *InstrProfSectNameCoff[] = {
155 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
156 SectNameCoff,
157 #include "llvm/ProfileData/InstrProfData.inc"
158 };
159
160 const char *InstrProfSectNamePrefix[] = {
161 #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
162 Prefix,
163 #include "llvm/ProfileData/InstrProfData.inc"
164 };
165
166 } // namespace
167
168 namespace llvm {
169
170 cl::opt<bool> DoInstrProfNameCompression(
171 "enable-name-compression",
172 cl::desc("Enable name/filename string compression"), cl::init(true));
173
getInstrProfSectionName(InstrProfSectKind IPSK,Triple::ObjectFormatType OF,bool AddSegmentInfo)174 std::string getInstrProfSectionName(InstrProfSectKind IPSK,
175 Triple::ObjectFormatType OF,
176 bool AddSegmentInfo) {
177 std::string SectName;
178
179 if (OF == Triple::MachO && AddSegmentInfo)
180 SectName = InstrProfSectNamePrefix[IPSK];
181
182 if (OF == Triple::COFF)
183 SectName += InstrProfSectNameCoff[IPSK];
184 else
185 SectName += InstrProfSectNameCommon[IPSK];
186
187 if (OF == Triple::MachO && IPSK == IPSK_data && AddSegmentInfo)
188 SectName += ",regular,live_support";
189
190 return SectName;
191 }
192
addError(instrprof_error IE)193 void SoftInstrProfErrors::addError(instrprof_error IE) {
194 if (IE == instrprof_error::success)
195 return;
196
197 if (FirstError == instrprof_error::success)
198 FirstError = IE;
199
200 switch (IE) {
201 case instrprof_error::hash_mismatch:
202 ++NumHashMismatches;
203 break;
204 case instrprof_error::count_mismatch:
205 ++NumCountMismatches;
206 break;
207 case instrprof_error::counter_overflow:
208 ++NumCounterOverflows;
209 break;
210 case instrprof_error::value_site_count_mismatch:
211 ++NumValueSiteCountMismatches;
212 break;
213 default:
214 llvm_unreachable("Not a soft error");
215 }
216 }
217
message() const218 std::string InstrProfError::message() const {
219 return getInstrProfErrString(Err);
220 }
221
222 char InstrProfError::ID = 0;
223
getPGOFuncName(StringRef RawFuncName,GlobalValue::LinkageTypes Linkage,StringRef FileName,uint64_t Version LLVM_ATTRIBUTE_UNUSED)224 std::string getPGOFuncName(StringRef RawFuncName,
225 GlobalValue::LinkageTypes Linkage,
226 StringRef FileName,
227 uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
228 return GlobalValue::getGlobalIdentifier(RawFuncName, Linkage, FileName);
229 }
230
231 // Strip NumPrefix level of directory name from PathNameStr. If the number of
232 // directory separators is less than NumPrefix, strip all the directories and
233 // leave base file name only.
stripDirPrefix(StringRef PathNameStr,uint32_t NumPrefix)234 static StringRef stripDirPrefix(StringRef PathNameStr, uint32_t NumPrefix) {
235 uint32_t Count = NumPrefix;
236 uint32_t Pos = 0, LastPos = 0;
237 for (auto & CI : PathNameStr) {
238 ++Pos;
239 if (llvm::sys::path::is_separator(CI)) {
240 LastPos = Pos;
241 --Count;
242 }
243 if (Count == 0)
244 break;
245 }
246 return PathNameStr.substr(LastPos);
247 }
248
249 // Return the PGOFuncName. This function has some special handling when called
250 // in LTO optimization. The following only applies when calling in LTO passes
251 // (when \c InLTO is true): LTO's internalization privatizes many global linkage
252 // symbols. This happens after value profile annotation, but those internal
253 // linkage functions should not have a source prefix.
254 // Additionally, for ThinLTO mode, exported internal functions are promoted
255 // and renamed. We need to ensure that the original internal PGO name is
256 // used when computing the GUID that is compared against the profiled GUIDs.
257 // To differentiate compiler generated internal symbols from original ones,
258 // PGOFuncName meta data are created and attached to the original internal
259 // symbols in the value profile annotation step
260 // (PGOUseFunc::annotateIndirectCallSites). If a symbol does not have the meta
261 // data, its original linkage must be non-internal.
getPGOFuncName(const Function & F,bool InLTO,uint64_t Version)262 std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
263 if (!InLTO) {
264 StringRef FileName(F.getParent()->getSourceFileName());
265 uint32_t StripLevel = StaticFuncFullModulePrefix ? 0 : (uint32_t)-1;
266 if (StripLevel < StaticFuncStripDirNamePrefix)
267 StripLevel = StaticFuncStripDirNamePrefix;
268 if (StripLevel)
269 FileName = stripDirPrefix(FileName, StripLevel);
270 return getPGOFuncName(F.getName(), F.getLinkage(), FileName, Version);
271 }
272
273 // In LTO mode (when InLTO is true), first check if there is a meta data.
274 if (MDNode *MD = getPGOFuncNameMetadata(F)) {
275 StringRef S = cast<MDString>(MD->getOperand(0))->getString();
276 return S.str();
277 }
278
279 // If there is no meta data, the function must be a global before the value
280 // profile annotation pass. Its current linkage may be internal if it is
281 // internalized in LTO mode.
282 return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
283 }
284
getFuncNameWithoutPrefix(StringRef PGOFuncName,StringRef FileName)285 StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
286 if (FileName.empty())
287 return PGOFuncName;
288 // Drop the file name including ':'. See also getPGOFuncName.
289 if (PGOFuncName.startswith(FileName))
290 PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
291 return PGOFuncName;
292 }
293
294 // \p FuncName is the string used as profile lookup key for the function. A
295 // symbol is created to hold the name. Return the legalized symbol name.
getPGOFuncNameVarName(StringRef FuncName,GlobalValue::LinkageTypes Linkage)296 std::string getPGOFuncNameVarName(StringRef FuncName,
297 GlobalValue::LinkageTypes Linkage) {
298 std::string VarName = std::string(getInstrProfNameVarPrefix());
299 VarName += FuncName;
300
301 if (!GlobalValue::isLocalLinkage(Linkage))
302 return VarName;
303
304 // Now fix up illegal chars in local VarName that may upset the assembler.
305 const char *InvalidChars = "-:<>/\"'";
306 size_t found = VarName.find_first_of(InvalidChars);
307 while (found != std::string::npos) {
308 VarName[found] = '_';
309 found = VarName.find_first_of(InvalidChars, found + 1);
310 }
311 return VarName;
312 }
313
createPGOFuncNameVar(Module & M,GlobalValue::LinkageTypes Linkage,StringRef PGOFuncName)314 GlobalVariable *createPGOFuncNameVar(Module &M,
315 GlobalValue::LinkageTypes Linkage,
316 StringRef PGOFuncName) {
317 // We generally want to match the function's linkage, but available_externally
318 // and extern_weak both have the wrong semantics, and anything that doesn't
319 // need to link across compilation units doesn't need to be visible at all.
320 if (Linkage == GlobalValue::ExternalWeakLinkage)
321 Linkage = GlobalValue::LinkOnceAnyLinkage;
322 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
323 Linkage = GlobalValue::LinkOnceODRLinkage;
324 else if (Linkage == GlobalValue::InternalLinkage ||
325 Linkage == GlobalValue::ExternalLinkage)
326 Linkage = GlobalValue::PrivateLinkage;
327
328 auto *Value =
329 ConstantDataArray::getString(M.getContext(), PGOFuncName, false);
330 auto FuncNameVar =
331 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
332 getPGOFuncNameVarName(PGOFuncName, Linkage));
333
334 // Hide the symbol so that we correctly get a copy for each executable.
335 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
336 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
337
338 return FuncNameVar;
339 }
340
createPGOFuncNameVar(Function & F,StringRef PGOFuncName)341 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName) {
342 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), PGOFuncName);
343 }
344
create(Module & M,bool InLTO)345 Error InstrProfSymtab::create(Module &M, bool InLTO) {
346 for (Function &F : M) {
347 // Function may not have a name: like using asm("") to overwrite the name.
348 // Ignore in this case.
349 if (!F.hasName())
350 continue;
351 const std::string &PGOFuncName = getPGOFuncName(F, InLTO);
352 if (Error E = addFuncName(PGOFuncName))
353 return E;
354 MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
355 // In ThinLTO, local function may have been promoted to global and have
356 // suffix ".llvm." added to the function name. We need to add the
357 // stripped function name to the symbol table so that we can find a match
358 // from profile.
359 //
360 // We may have other suffixes similar as ".llvm." which are needed to
361 // be stripped before the matching, but ".__uniq." suffix which is used
362 // to differentiate internal linkage functions in different modules
363 // should be kept. Now this is the only suffix with the pattern ".xxx"
364 // which is kept before matching.
365 const std::string UniqSuffix = ".__uniq.";
366 auto pos = PGOFuncName.find(UniqSuffix);
367 // Search '.' after ".__uniq." if ".__uniq." exists, otherwise
368 // search '.' from the beginning.
369 if (pos != std::string::npos)
370 pos += UniqSuffix.length();
371 else
372 pos = 0;
373 pos = PGOFuncName.find('.', pos);
374 if (pos != std::string::npos && pos != 0) {
375 const std::string &OtherFuncName = PGOFuncName.substr(0, pos);
376 if (Error E = addFuncName(OtherFuncName))
377 return E;
378 MD5FuncMap.emplace_back(Function::getGUID(OtherFuncName), &F);
379 }
380 }
381 Sorted = false;
382 finalizeSymtab();
383 return Error::success();
384 }
385
getFunctionHashFromAddress(uint64_t Address)386 uint64_t InstrProfSymtab::getFunctionHashFromAddress(uint64_t Address) {
387 finalizeSymtab();
388 auto It = partition_point(AddrToMD5Map, [=](std::pair<uint64_t, uint64_t> A) {
389 return A.first < Address;
390 });
391 // Raw function pointer collected by value profiler may be from
392 // external functions that are not instrumented. They won't have
393 // mapping data to be used by the deserializer. Force the value to
394 // be 0 in this case.
395 if (It != AddrToMD5Map.end() && It->first == Address)
396 return (uint64_t)It->second;
397 return 0;
398 }
399
collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,bool doCompression,std::string & Result)400 Error collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,
401 bool doCompression, std::string &Result) {
402 assert(!NameStrs.empty() && "No name data to emit");
403
404 uint8_t Header[16], *P = Header;
405 std::string UncompressedNameStrings =
406 join(NameStrs.begin(), NameStrs.end(), getInstrProfNameSeparator());
407
408 assert(StringRef(UncompressedNameStrings)
409 .count(getInstrProfNameSeparator()) == (NameStrs.size() - 1) &&
410 "PGO name is invalid (contains separator token)");
411
412 unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
413 P += EncLen;
414
415 auto WriteStringToResult = [&](size_t CompressedLen, StringRef InputStr) {
416 EncLen = encodeULEB128(CompressedLen, P);
417 P += EncLen;
418 char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
419 unsigned HeaderLen = P - &Header[0];
420 Result.append(HeaderStr, HeaderLen);
421 Result += InputStr;
422 return Error::success();
423 };
424
425 if (!doCompression) {
426 return WriteStringToResult(0, UncompressedNameStrings);
427 }
428
429 SmallString<128> CompressedNameStrings;
430 Error E = zlib::compress(StringRef(UncompressedNameStrings),
431 CompressedNameStrings, zlib::BestSizeCompression);
432 if (E) {
433 consumeError(std::move(E));
434 return make_error<InstrProfError>(instrprof_error::compress_failed);
435 }
436
437 return WriteStringToResult(CompressedNameStrings.size(),
438 CompressedNameStrings);
439 }
440
getPGOFuncNameVarInitializer(GlobalVariable * NameVar)441 StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar) {
442 auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
443 StringRef NameStr =
444 Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
445 return NameStr;
446 }
447
collectPGOFuncNameStrings(ArrayRef<GlobalVariable * > NameVars,std::string & Result,bool doCompression)448 Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
449 std::string &Result, bool doCompression) {
450 std::vector<std::string> NameStrs;
451 for (auto *NameVar : NameVars) {
452 NameStrs.push_back(std::string(getPGOFuncNameVarInitializer(NameVar)));
453 }
454 return collectPGOFuncNameStrings(
455 NameStrs, zlib::isAvailable() && doCompression, Result);
456 }
457
readPGOFuncNameStrings(StringRef NameStrings,InstrProfSymtab & Symtab)458 Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
459 const uint8_t *P = NameStrings.bytes_begin();
460 const uint8_t *EndP = NameStrings.bytes_end();
461 while (P < EndP) {
462 uint32_t N;
463 uint64_t UncompressedSize = decodeULEB128(P, &N);
464 P += N;
465 uint64_t CompressedSize = decodeULEB128(P, &N);
466 P += N;
467 bool isCompressed = (CompressedSize != 0);
468 SmallString<128> UncompressedNameStrings;
469 StringRef NameStrings;
470 if (isCompressed) {
471 if (!llvm::zlib::isAvailable())
472 return make_error<InstrProfError>(instrprof_error::zlib_unavailable);
473
474 StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
475 CompressedSize);
476 if (Error E =
477 zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
478 UncompressedSize)) {
479 consumeError(std::move(E));
480 return make_error<InstrProfError>(instrprof_error::uncompress_failed);
481 }
482 P += CompressedSize;
483 NameStrings = StringRef(UncompressedNameStrings.data(),
484 UncompressedNameStrings.size());
485 } else {
486 NameStrings =
487 StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
488 P += UncompressedSize;
489 }
490 // Now parse the name strings.
491 SmallVector<StringRef, 0> Names;
492 NameStrings.split(Names, getInstrProfNameSeparator());
493 for (StringRef &Name : Names)
494 if (Error E = Symtab.addFuncName(Name))
495 return E;
496
497 while (P < EndP && *P == 0)
498 P++;
499 }
500 return Error::success();
501 }
502
accumulateCounts(CountSumOrPercent & Sum) const503 void InstrProfRecord::accumulateCounts(CountSumOrPercent &Sum) const {
504 uint64_t FuncSum = 0;
505 Sum.NumEntries += Counts.size();
506 for (size_t F = 0, E = Counts.size(); F < E; ++F)
507 FuncSum += Counts[F];
508 Sum.CountSum += FuncSum;
509
510 for (uint32_t VK = IPVK_First; VK <= IPVK_Last; ++VK) {
511 uint64_t KindSum = 0;
512 uint32_t NumValueSites = getNumValueSites(VK);
513 for (size_t I = 0; I < NumValueSites; ++I) {
514 uint32_t NV = getNumValueDataForSite(VK, I);
515 std::unique_ptr<InstrProfValueData[]> VD = getValueForSite(VK, I);
516 for (uint32_t V = 0; V < NV; V++)
517 KindSum += VD[V].Count;
518 }
519 Sum.ValueCounts[VK] += KindSum;
520 }
521 }
522
overlap(InstrProfValueSiteRecord & Input,uint32_t ValueKind,OverlapStats & Overlap,OverlapStats & FuncLevelOverlap)523 void InstrProfValueSiteRecord::overlap(InstrProfValueSiteRecord &Input,
524 uint32_t ValueKind,
525 OverlapStats &Overlap,
526 OverlapStats &FuncLevelOverlap) {
527 this->sortByTargetValues();
528 Input.sortByTargetValues();
529 double Score = 0.0f, FuncLevelScore = 0.0f;
530 auto I = ValueData.begin();
531 auto IE = ValueData.end();
532 auto J = Input.ValueData.begin();
533 auto JE = Input.ValueData.end();
534 while (I != IE && J != JE) {
535 if (I->Value == J->Value) {
536 Score += OverlapStats::score(I->Count, J->Count,
537 Overlap.Base.ValueCounts[ValueKind],
538 Overlap.Test.ValueCounts[ValueKind]);
539 FuncLevelScore += OverlapStats::score(
540 I->Count, J->Count, FuncLevelOverlap.Base.ValueCounts[ValueKind],
541 FuncLevelOverlap.Test.ValueCounts[ValueKind]);
542 ++I;
543 } else if (I->Value < J->Value) {
544 ++I;
545 continue;
546 }
547 ++J;
548 }
549 Overlap.Overlap.ValueCounts[ValueKind] += Score;
550 FuncLevelOverlap.Overlap.ValueCounts[ValueKind] += FuncLevelScore;
551 }
552
553 // Return false on mismatch.
overlapValueProfData(uint32_t ValueKind,InstrProfRecord & Other,OverlapStats & Overlap,OverlapStats & FuncLevelOverlap)554 void InstrProfRecord::overlapValueProfData(uint32_t ValueKind,
555 InstrProfRecord &Other,
556 OverlapStats &Overlap,
557 OverlapStats &FuncLevelOverlap) {
558 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
559 assert(ThisNumValueSites == Other.getNumValueSites(ValueKind));
560 if (!ThisNumValueSites)
561 return;
562
563 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
564 getOrCreateValueSitesForKind(ValueKind);
565 MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
566 Other.getValueSitesForKind(ValueKind);
567 for (uint32_t I = 0; I < ThisNumValueSites; I++)
568 ThisSiteRecords[I].overlap(OtherSiteRecords[I], ValueKind, Overlap,
569 FuncLevelOverlap);
570 }
571
overlap(InstrProfRecord & Other,OverlapStats & Overlap,OverlapStats & FuncLevelOverlap,uint64_t ValueCutoff)572 void InstrProfRecord::overlap(InstrProfRecord &Other, OverlapStats &Overlap,
573 OverlapStats &FuncLevelOverlap,
574 uint64_t ValueCutoff) {
575 // FuncLevel CountSum for other should already computed and nonzero.
576 assert(FuncLevelOverlap.Test.CountSum >= 1.0f);
577 accumulateCounts(FuncLevelOverlap.Base);
578 bool Mismatch = (Counts.size() != Other.Counts.size());
579
580 // Check if the value profiles mismatch.
581 if (!Mismatch) {
582 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind) {
583 uint32_t ThisNumValueSites = getNumValueSites(Kind);
584 uint32_t OtherNumValueSites = Other.getNumValueSites(Kind);
585 if (ThisNumValueSites != OtherNumValueSites) {
586 Mismatch = true;
587 break;
588 }
589 }
590 }
591 if (Mismatch) {
592 Overlap.addOneMismatch(FuncLevelOverlap.Test);
593 return;
594 }
595
596 // Compute overlap for value counts.
597 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
598 overlapValueProfData(Kind, Other, Overlap, FuncLevelOverlap);
599
600 double Score = 0.0;
601 uint64_t MaxCount = 0;
602 // Compute overlap for edge counts.
603 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
604 Score += OverlapStats::score(Counts[I], Other.Counts[I],
605 Overlap.Base.CountSum, Overlap.Test.CountSum);
606 MaxCount = std::max(Other.Counts[I], MaxCount);
607 }
608 Overlap.Overlap.CountSum += Score;
609 Overlap.Overlap.NumEntries += 1;
610
611 if (MaxCount >= ValueCutoff) {
612 double FuncScore = 0.0;
613 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I)
614 FuncScore += OverlapStats::score(Counts[I], Other.Counts[I],
615 FuncLevelOverlap.Base.CountSum,
616 FuncLevelOverlap.Test.CountSum);
617 FuncLevelOverlap.Overlap.CountSum = FuncScore;
618 FuncLevelOverlap.Overlap.NumEntries = Other.Counts.size();
619 FuncLevelOverlap.Valid = true;
620 }
621 }
622
merge(InstrProfValueSiteRecord & Input,uint64_t Weight,function_ref<void (instrprof_error)> Warn)623 void InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
624 uint64_t Weight,
625 function_ref<void(instrprof_error)> Warn) {
626 this->sortByTargetValues();
627 Input.sortByTargetValues();
628 auto I = ValueData.begin();
629 auto IE = ValueData.end();
630 for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
631 ++J) {
632 while (I != IE && I->Value < J->Value)
633 ++I;
634 if (I != IE && I->Value == J->Value) {
635 bool Overflowed;
636 I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
637 if (Overflowed)
638 Warn(instrprof_error::counter_overflow);
639 ++I;
640 continue;
641 }
642 ValueData.insert(I, *J);
643 }
644 }
645
scale(uint64_t N,uint64_t D,function_ref<void (instrprof_error)> Warn)646 void InstrProfValueSiteRecord::scale(uint64_t N, uint64_t D,
647 function_ref<void(instrprof_error)> Warn) {
648 for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
649 bool Overflowed;
650 I->Count = SaturatingMultiply(I->Count, N, &Overflowed) / D;
651 if (Overflowed)
652 Warn(instrprof_error::counter_overflow);
653 }
654 }
655
656 // Merge Value Profile data from Src record to this record for ValueKind.
657 // Scale merged value counts by \p Weight.
mergeValueProfData(uint32_t ValueKind,InstrProfRecord & Src,uint64_t Weight,function_ref<void (instrprof_error)> Warn)658 void InstrProfRecord::mergeValueProfData(
659 uint32_t ValueKind, InstrProfRecord &Src, uint64_t Weight,
660 function_ref<void(instrprof_error)> Warn) {
661 uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
662 uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
663 if (ThisNumValueSites != OtherNumValueSites) {
664 Warn(instrprof_error::value_site_count_mismatch);
665 return;
666 }
667 if (!ThisNumValueSites)
668 return;
669 std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
670 getOrCreateValueSitesForKind(ValueKind);
671 MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
672 Src.getValueSitesForKind(ValueKind);
673 for (uint32_t I = 0; I < ThisNumValueSites; I++)
674 ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight, Warn);
675 }
676
merge(InstrProfRecord & Other,uint64_t Weight,function_ref<void (instrprof_error)> Warn)677 void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
678 function_ref<void(instrprof_error)> Warn) {
679 // If the number of counters doesn't match we either have bad data
680 // or a hash collision.
681 if (Counts.size() != Other.Counts.size()) {
682 Warn(instrprof_error::count_mismatch);
683 return;
684 }
685
686 for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
687 bool Overflowed;
688 Counts[I] =
689 SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
690 if (Overflowed)
691 Warn(instrprof_error::counter_overflow);
692 }
693
694 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
695 mergeValueProfData(Kind, Other, Weight, Warn);
696 }
697
scaleValueProfData(uint32_t ValueKind,uint64_t N,uint64_t D,function_ref<void (instrprof_error)> Warn)698 void InstrProfRecord::scaleValueProfData(
699 uint32_t ValueKind, uint64_t N, uint64_t D,
700 function_ref<void(instrprof_error)> Warn) {
701 for (auto &R : getValueSitesForKind(ValueKind))
702 R.scale(N, D, Warn);
703 }
704
scale(uint64_t N,uint64_t D,function_ref<void (instrprof_error)> Warn)705 void InstrProfRecord::scale(uint64_t N, uint64_t D,
706 function_ref<void(instrprof_error)> Warn) {
707 assert(D != 0 && "D cannot be 0");
708 for (auto &Count : this->Counts) {
709 bool Overflowed;
710 Count = SaturatingMultiply(Count, N, &Overflowed) / D;
711 if (Overflowed)
712 Warn(instrprof_error::counter_overflow);
713 }
714 for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
715 scaleValueProfData(Kind, N, D, Warn);
716 }
717
718 // Map indirect call target name hash to name string.
remapValue(uint64_t Value,uint32_t ValueKind,InstrProfSymtab * SymTab)719 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
720 InstrProfSymtab *SymTab) {
721 if (!SymTab)
722 return Value;
723
724 if (ValueKind == IPVK_IndirectCallTarget)
725 return SymTab->getFunctionHashFromAddress(Value);
726
727 return Value;
728 }
729
addValueData(uint32_t ValueKind,uint32_t Site,InstrProfValueData * VData,uint32_t N,InstrProfSymtab * ValueMap)730 void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
731 InstrProfValueData *VData, uint32_t N,
732 InstrProfSymtab *ValueMap) {
733 for (uint32_t I = 0; I < N; I++) {
734 VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
735 }
736 std::vector<InstrProfValueSiteRecord> &ValueSites =
737 getOrCreateValueSitesForKind(ValueKind);
738 if (N == 0)
739 ValueSites.emplace_back();
740 else
741 ValueSites.emplace_back(VData, VData + N);
742 }
743
744 #define INSTR_PROF_COMMON_API_IMPL
745 #include "llvm/ProfileData/InstrProfData.inc"
746
747 /*!
748 * ValueProfRecordClosure Interface implementation for InstrProfRecord
749 * class. These C wrappers are used as adaptors so that C++ code can be
750 * invoked as callbacks.
751 */
getNumValueKindsInstrProf(const void * Record)752 uint32_t getNumValueKindsInstrProf(const void *Record) {
753 return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
754 }
755
getNumValueSitesInstrProf(const void * Record,uint32_t VKind)756 uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
757 return reinterpret_cast<const InstrProfRecord *>(Record)
758 ->getNumValueSites(VKind);
759 }
760
getNumValueDataInstrProf(const void * Record,uint32_t VKind)761 uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
762 return reinterpret_cast<const InstrProfRecord *>(Record)
763 ->getNumValueData(VKind);
764 }
765
getNumValueDataForSiteInstrProf(const void * R,uint32_t VK,uint32_t S)766 uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
767 uint32_t S) {
768 return reinterpret_cast<const InstrProfRecord *>(R)
769 ->getNumValueDataForSite(VK, S);
770 }
771
getValueForSiteInstrProf(const void * R,InstrProfValueData * Dst,uint32_t K,uint32_t S)772 void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
773 uint32_t K, uint32_t S) {
774 reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(Dst, K, S);
775 }
776
allocValueProfDataInstrProf(size_t TotalSizeInBytes)777 ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
778 ValueProfData *VD =
779 (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
780 memset(VD, 0, TotalSizeInBytes);
781 return VD;
782 }
783
784 static ValueProfRecordClosure InstrProfRecordClosure = {
785 nullptr,
786 getNumValueKindsInstrProf,
787 getNumValueSitesInstrProf,
788 getNumValueDataInstrProf,
789 getNumValueDataForSiteInstrProf,
790 nullptr,
791 getValueForSiteInstrProf,
792 allocValueProfDataInstrProf};
793
794 // Wrapper implementation using the closure mechanism.
getSize(const InstrProfRecord & Record)795 uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
796 auto Closure = InstrProfRecordClosure;
797 Closure.Record = &Record;
798 return getValueProfDataSize(&Closure);
799 }
800
801 // Wrapper implementation using the closure mechanism.
802 std::unique_ptr<ValueProfData>
serializeFrom(const InstrProfRecord & Record)803 ValueProfData::serializeFrom(const InstrProfRecord &Record) {
804 InstrProfRecordClosure.Record = &Record;
805
806 std::unique_ptr<ValueProfData> VPD(
807 serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
808 return VPD;
809 }
810
deserializeTo(InstrProfRecord & Record,InstrProfSymtab * SymTab)811 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
812 InstrProfSymtab *SymTab) {
813 Record.reserveSites(Kind, NumValueSites);
814
815 InstrProfValueData *ValueData = getValueProfRecordValueData(this);
816 for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
817 uint8_t ValueDataCount = this->SiteCountArray[VSite];
818 Record.addValueData(Kind, VSite, ValueData, ValueDataCount, SymTab);
819 ValueData += ValueDataCount;
820 }
821 }
822
823 // For writing/serializing, Old is the host endianness, and New is
824 // byte order intended on disk. For Reading/deserialization, Old
825 // is the on-disk source endianness, and New is the host endianness.
swapBytes(support::endianness Old,support::endianness New)826 void ValueProfRecord::swapBytes(support::endianness Old,
827 support::endianness New) {
828 using namespace support;
829
830 if (Old == New)
831 return;
832
833 if (getHostEndianness() != Old) {
834 sys::swapByteOrder<uint32_t>(NumValueSites);
835 sys::swapByteOrder<uint32_t>(Kind);
836 }
837 uint32_t ND = getValueProfRecordNumValueData(this);
838 InstrProfValueData *VD = getValueProfRecordValueData(this);
839
840 // No need to swap byte array: SiteCountArrray.
841 for (uint32_t I = 0; I < ND; I++) {
842 sys::swapByteOrder<uint64_t>(VD[I].Value);
843 sys::swapByteOrder<uint64_t>(VD[I].Count);
844 }
845 if (getHostEndianness() == Old) {
846 sys::swapByteOrder<uint32_t>(NumValueSites);
847 sys::swapByteOrder<uint32_t>(Kind);
848 }
849 }
850
deserializeTo(InstrProfRecord & Record,InstrProfSymtab * SymTab)851 void ValueProfData::deserializeTo(InstrProfRecord &Record,
852 InstrProfSymtab *SymTab) {
853 if (NumValueKinds == 0)
854 return;
855
856 ValueProfRecord *VR = getFirstValueProfRecord(this);
857 for (uint32_t K = 0; K < NumValueKinds; K++) {
858 VR->deserializeTo(Record, SymTab);
859 VR = getValueProfRecordNext(VR);
860 }
861 }
862
863 template <class T>
swapToHostOrder(const unsigned char * & D,support::endianness Orig)864 static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
865 using namespace support;
866
867 if (Orig == little)
868 return endian::readNext<T, little, unaligned>(D);
869 else
870 return endian::readNext<T, big, unaligned>(D);
871 }
872
allocValueProfData(uint32_t TotalSize)873 static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
874 return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
875 ValueProfData());
876 }
877
checkIntegrity()878 Error ValueProfData::checkIntegrity() {
879 if (NumValueKinds > IPVK_Last + 1)
880 return make_error<InstrProfError>(instrprof_error::malformed);
881 // Total size needs to be mulltiple of quadword size.
882 if (TotalSize % sizeof(uint64_t))
883 return make_error<InstrProfError>(instrprof_error::malformed);
884
885 ValueProfRecord *VR = getFirstValueProfRecord(this);
886 for (uint32_t K = 0; K < this->NumValueKinds; K++) {
887 if (VR->Kind > IPVK_Last)
888 return make_error<InstrProfError>(instrprof_error::malformed);
889 VR = getValueProfRecordNext(VR);
890 if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
891 return make_error<InstrProfError>(instrprof_error::malformed);
892 }
893 return Error::success();
894 }
895
896 Expected<std::unique_ptr<ValueProfData>>
getValueProfData(const unsigned char * D,const unsigned char * const BufferEnd,support::endianness Endianness)897 ValueProfData::getValueProfData(const unsigned char *D,
898 const unsigned char *const BufferEnd,
899 support::endianness Endianness) {
900 using namespace support;
901
902 if (D + sizeof(ValueProfData) > BufferEnd)
903 return make_error<InstrProfError>(instrprof_error::truncated);
904
905 const unsigned char *Header = D;
906 uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
907 if (D + TotalSize > BufferEnd)
908 return make_error<InstrProfError>(instrprof_error::too_large);
909
910 std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
911 memcpy(VPD.get(), D, TotalSize);
912 // Byte swap.
913 VPD->swapBytesToHost(Endianness);
914
915 Error E = VPD->checkIntegrity();
916 if (E)
917 return std::move(E);
918
919 return std::move(VPD);
920 }
921
swapBytesToHost(support::endianness Endianness)922 void ValueProfData::swapBytesToHost(support::endianness Endianness) {
923 using namespace support;
924
925 if (Endianness == getHostEndianness())
926 return;
927
928 sys::swapByteOrder<uint32_t>(TotalSize);
929 sys::swapByteOrder<uint32_t>(NumValueKinds);
930
931 ValueProfRecord *VR = getFirstValueProfRecord(this);
932 for (uint32_t K = 0; K < NumValueKinds; K++) {
933 VR->swapBytes(Endianness, getHostEndianness());
934 VR = getValueProfRecordNext(VR);
935 }
936 }
937
swapBytesFromHost(support::endianness Endianness)938 void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
939 using namespace support;
940
941 if (Endianness == getHostEndianness())
942 return;
943
944 ValueProfRecord *VR = getFirstValueProfRecord(this);
945 for (uint32_t K = 0; K < NumValueKinds; K++) {
946 ValueProfRecord *NVR = getValueProfRecordNext(VR);
947 VR->swapBytes(getHostEndianness(), Endianness);
948 VR = NVR;
949 }
950 sys::swapByteOrder<uint32_t>(TotalSize);
951 sys::swapByteOrder<uint32_t>(NumValueKinds);
952 }
953
annotateValueSite(Module & M,Instruction & Inst,const InstrProfRecord & InstrProfR,InstrProfValueKind ValueKind,uint32_t SiteIdx,uint32_t MaxMDCount)954 void annotateValueSite(Module &M, Instruction &Inst,
955 const InstrProfRecord &InstrProfR,
956 InstrProfValueKind ValueKind, uint32_t SiteIdx,
957 uint32_t MaxMDCount) {
958 uint32_t NV = InstrProfR.getNumValueDataForSite(ValueKind, SiteIdx);
959 if (!NV)
960 return;
961
962 uint64_t Sum = 0;
963 std::unique_ptr<InstrProfValueData[]> VD =
964 InstrProfR.getValueForSite(ValueKind, SiteIdx, &Sum);
965
966 ArrayRef<InstrProfValueData> VDs(VD.get(), NV);
967 annotateValueSite(M, Inst, VDs, Sum, ValueKind, MaxMDCount);
968 }
969
annotateValueSite(Module & M,Instruction & Inst,ArrayRef<InstrProfValueData> VDs,uint64_t Sum,InstrProfValueKind ValueKind,uint32_t MaxMDCount)970 void annotateValueSite(Module &M, Instruction &Inst,
971 ArrayRef<InstrProfValueData> VDs,
972 uint64_t Sum, InstrProfValueKind ValueKind,
973 uint32_t MaxMDCount) {
974 LLVMContext &Ctx = M.getContext();
975 MDBuilder MDHelper(Ctx);
976 SmallVector<Metadata *, 3> Vals;
977 // Tag
978 Vals.push_back(MDHelper.createString("VP"));
979 // Value Kind
980 Vals.push_back(MDHelper.createConstant(
981 ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
982 // Total Count
983 Vals.push_back(
984 MDHelper.createConstant(ConstantInt::get(Type::getInt64Ty(Ctx), Sum)));
985
986 // Value Profile Data
987 uint32_t MDCount = MaxMDCount;
988 for (auto &VD : VDs) {
989 Vals.push_back(MDHelper.createConstant(
990 ConstantInt::get(Type::getInt64Ty(Ctx), VD.Value)));
991 Vals.push_back(MDHelper.createConstant(
992 ConstantInt::get(Type::getInt64Ty(Ctx), VD.Count)));
993 if (--MDCount == 0)
994 break;
995 }
996 Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
997 }
998
getValueProfDataFromInst(const Instruction & Inst,InstrProfValueKind ValueKind,uint32_t MaxNumValueData,InstrProfValueData ValueData[],uint32_t & ActualNumValueData,uint64_t & TotalC,bool GetNoICPValue)999 bool getValueProfDataFromInst(const Instruction &Inst,
1000 InstrProfValueKind ValueKind,
1001 uint32_t MaxNumValueData,
1002 InstrProfValueData ValueData[],
1003 uint32_t &ActualNumValueData, uint64_t &TotalC,
1004 bool GetNoICPValue) {
1005 MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
1006 if (!MD)
1007 return false;
1008
1009 unsigned NOps = MD->getNumOperands();
1010
1011 if (NOps < 5)
1012 return false;
1013
1014 // Operand 0 is a string tag "VP":
1015 MDString *Tag = cast<MDString>(MD->getOperand(0));
1016 if (!Tag)
1017 return false;
1018
1019 if (!Tag->getString().equals("VP"))
1020 return false;
1021
1022 // Now check kind:
1023 ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
1024 if (!KindInt)
1025 return false;
1026 if (KindInt->getZExtValue() != ValueKind)
1027 return false;
1028
1029 // Get total count
1030 ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
1031 if (!TotalCInt)
1032 return false;
1033 TotalC = TotalCInt->getZExtValue();
1034
1035 ActualNumValueData = 0;
1036
1037 for (unsigned I = 3; I < NOps; I += 2) {
1038 if (ActualNumValueData >= MaxNumValueData)
1039 break;
1040 ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
1041 ConstantInt *Count =
1042 mdconst::dyn_extract<ConstantInt>(MD->getOperand(I + 1));
1043 if (!Value || !Count)
1044 return false;
1045 uint64_t CntValue = Count->getZExtValue();
1046 if (!GetNoICPValue && (CntValue == NOMORE_ICP_MAGICNUM))
1047 continue;
1048 ValueData[ActualNumValueData].Value = Value->getZExtValue();
1049 ValueData[ActualNumValueData].Count = CntValue;
1050 ActualNumValueData++;
1051 }
1052 return true;
1053 }
1054
getPGOFuncNameMetadata(const Function & F)1055 MDNode *getPGOFuncNameMetadata(const Function &F) {
1056 return F.getMetadata(getPGOFuncNameMetadataName());
1057 }
1058
createPGOFuncNameMetadata(Function & F,StringRef PGOFuncName)1059 void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
1060 // Only for internal linkage functions.
1061 if (PGOFuncName == F.getName())
1062 return;
1063 // Don't create duplicated meta-data.
1064 if (getPGOFuncNameMetadata(F))
1065 return;
1066 LLVMContext &C = F.getContext();
1067 MDNode *N = MDNode::get(C, MDString::get(C, PGOFuncName));
1068 F.setMetadata(getPGOFuncNameMetadataName(), N);
1069 }
1070
needsComdatForCounter(const Function & F,const Module & M)1071 bool needsComdatForCounter(const Function &F, const Module &M) {
1072 if (F.hasComdat())
1073 return true;
1074
1075 if (!Triple(M.getTargetTriple()).supportsCOMDAT())
1076 return false;
1077
1078 // See createPGOFuncNameVar for more details. To avoid link errors, profile
1079 // counters for function with available_externally linkage needs to be changed
1080 // to linkonce linkage. On ELF based systems, this leads to weak symbols to be
1081 // created. Without using comdat, duplicate entries won't be removed by the
1082 // linker leading to increased data segement size and raw profile size. Even
1083 // worse, since the referenced counter from profile per-function data object
1084 // will be resolved to the common strong definition, the profile counts for
1085 // available_externally functions will end up being duplicated in raw profile
1086 // data. This can result in distorted profile as the counts of those dups
1087 // will be accumulated by the profile merger.
1088 GlobalValue::LinkageTypes Linkage = F.getLinkage();
1089 if (Linkage != GlobalValue::ExternalWeakLinkage &&
1090 Linkage != GlobalValue::AvailableExternallyLinkage)
1091 return false;
1092
1093 return true;
1094 }
1095
1096 // Check if INSTR_PROF_RAW_VERSION_VAR is defined.
isIRPGOFlagSet(const Module * M)1097 bool isIRPGOFlagSet(const Module *M) {
1098 auto IRInstrVar =
1099 M->getNamedGlobal(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
1100 if (!IRInstrVar || IRInstrVar->isDeclaration() ||
1101 IRInstrVar->hasLocalLinkage())
1102 return false;
1103
1104 // Check if the flag is set.
1105 if (!IRInstrVar->hasInitializer())
1106 return false;
1107
1108 auto *InitVal = dyn_cast_or_null<ConstantInt>(IRInstrVar->getInitializer());
1109 if (!InitVal)
1110 return false;
1111 return (InitVal->getZExtValue() & VARIANT_MASK_IR_PROF) != 0;
1112 }
1113
1114 // Check if we can safely rename this Comdat function.
canRenameComdatFunc(const Function & F,bool CheckAddressTaken)1115 bool canRenameComdatFunc(const Function &F, bool CheckAddressTaken) {
1116 if (F.getName().empty())
1117 return false;
1118 if (!needsComdatForCounter(F, *(F.getParent())))
1119 return false;
1120 // Unsafe to rename the address-taken function (which can be used in
1121 // function comparison).
1122 if (CheckAddressTaken && F.hasAddressTaken())
1123 return false;
1124 // Only safe to do if this function may be discarded if it is not used
1125 // in the compilation unit.
1126 if (!GlobalValue::isDiscardableIfUnused(F.getLinkage()))
1127 return false;
1128
1129 // For AvailableExternallyLinkage functions.
1130 if (!F.hasComdat()) {
1131 assert(F.getLinkage() == GlobalValue::AvailableExternallyLinkage);
1132 return true;
1133 }
1134 return true;
1135 }
1136
1137 // Create a COMDAT variable INSTR_PROF_RAW_VERSION_VAR to make the runtime
1138 // aware this is an ir_level profile so it can set the version flag.
createIRLevelProfileFlagVar(Module & M,bool IsCS,bool InstrEntryBBEnabled)1139 void createIRLevelProfileFlagVar(Module &M, bool IsCS,
1140 bool InstrEntryBBEnabled) {
1141 const StringRef VarName(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
1142 Type *IntTy64 = Type::getInt64Ty(M.getContext());
1143 uint64_t ProfileVersion = (INSTR_PROF_RAW_VERSION | VARIANT_MASK_IR_PROF);
1144 if (IsCS)
1145 ProfileVersion |= VARIANT_MASK_CSIR_PROF;
1146 if (InstrEntryBBEnabled)
1147 ProfileVersion |= VARIANT_MASK_INSTR_ENTRY;
1148 auto IRLevelVersionVariable = new GlobalVariable(
1149 M, IntTy64, true, GlobalValue::WeakAnyLinkage,
1150 Constant::getIntegerValue(IntTy64, APInt(64, ProfileVersion)), VarName);
1151 IRLevelVersionVariable->setVisibility(GlobalValue::DefaultVisibility);
1152 Triple TT(M.getTargetTriple());
1153 if (TT.supportsCOMDAT()) {
1154 IRLevelVersionVariable->setLinkage(GlobalValue::ExternalLinkage);
1155 IRLevelVersionVariable->setComdat(M.getOrInsertComdat(VarName));
1156 }
1157 }
1158
1159 // Create the variable for the profile file name.
createProfileFileNameVar(Module & M,StringRef InstrProfileOutput)1160 void createProfileFileNameVar(Module &M, StringRef InstrProfileOutput) {
1161 if (InstrProfileOutput.empty())
1162 return;
1163 Constant *ProfileNameConst =
1164 ConstantDataArray::getString(M.getContext(), InstrProfileOutput, true);
1165 GlobalVariable *ProfileNameVar = new GlobalVariable(
1166 M, ProfileNameConst->getType(), true, GlobalValue::WeakAnyLinkage,
1167 ProfileNameConst, INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR));
1168 Triple TT(M.getTargetTriple());
1169 if (TT.supportsCOMDAT()) {
1170 ProfileNameVar->setLinkage(GlobalValue::ExternalLinkage);
1171 ProfileNameVar->setComdat(M.getOrInsertComdat(
1172 StringRef(INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR))));
1173 }
1174 }
1175
accumulateCounts(const std::string & BaseFilename,const std::string & TestFilename,bool IsCS)1176 Error OverlapStats::accumulateCounts(const std::string &BaseFilename,
1177 const std::string &TestFilename,
1178 bool IsCS) {
1179 auto getProfileSum = [IsCS](const std::string &Filename,
1180 CountSumOrPercent &Sum) -> Error {
1181 auto ReaderOrErr = InstrProfReader::create(Filename);
1182 if (Error E = ReaderOrErr.takeError()) {
1183 return E;
1184 }
1185 auto Reader = std::move(ReaderOrErr.get());
1186 Reader->accumulateCounts(Sum, IsCS);
1187 return Error::success();
1188 };
1189 auto Ret = getProfileSum(BaseFilename, Base);
1190 if (Ret)
1191 return Ret;
1192 Ret = getProfileSum(TestFilename, Test);
1193 if (Ret)
1194 return Ret;
1195 this->BaseFilename = &BaseFilename;
1196 this->TestFilename = &TestFilename;
1197 Valid = true;
1198 return Error::success();
1199 }
1200
addOneMismatch(const CountSumOrPercent & MismatchFunc)1201 void OverlapStats::addOneMismatch(const CountSumOrPercent &MismatchFunc) {
1202 Mismatch.NumEntries += 1;
1203 Mismatch.CountSum += MismatchFunc.CountSum / Test.CountSum;
1204 for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1205 if (Test.ValueCounts[I] >= 1.0f)
1206 Mismatch.ValueCounts[I] +=
1207 MismatchFunc.ValueCounts[I] / Test.ValueCounts[I];
1208 }
1209 }
1210
addOneUnique(const CountSumOrPercent & UniqueFunc)1211 void OverlapStats::addOneUnique(const CountSumOrPercent &UniqueFunc) {
1212 Unique.NumEntries += 1;
1213 Unique.CountSum += UniqueFunc.CountSum / Test.CountSum;
1214 for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1215 if (Test.ValueCounts[I] >= 1.0f)
1216 Unique.ValueCounts[I] += UniqueFunc.ValueCounts[I] / Test.ValueCounts[I];
1217 }
1218 }
1219
dump(raw_fd_ostream & OS) const1220 void OverlapStats::dump(raw_fd_ostream &OS) const {
1221 if (!Valid)
1222 return;
1223
1224 const char *EntryName =
1225 (Level == ProgramLevel ? "functions" : "edge counters");
1226 if (Level == ProgramLevel) {
1227 OS << "Profile overlap infomation for base_profile: " << *BaseFilename
1228 << " and test_profile: " << *TestFilename << "\nProgram level:\n";
1229 } else {
1230 OS << "Function level:\n"
1231 << " Function: " << FuncName << " (Hash=" << FuncHash << ")\n";
1232 }
1233
1234 OS << " # of " << EntryName << " overlap: " << Overlap.NumEntries << "\n";
1235 if (Mismatch.NumEntries)
1236 OS << " # of " << EntryName << " mismatch: " << Mismatch.NumEntries
1237 << "\n";
1238 if (Unique.NumEntries)
1239 OS << " # of " << EntryName
1240 << " only in test_profile: " << Unique.NumEntries << "\n";
1241
1242 OS << " Edge profile overlap: " << format("%.3f%%", Overlap.CountSum * 100)
1243 << "\n";
1244 if (Mismatch.NumEntries)
1245 OS << " Mismatched count percentage (Edge): "
1246 << format("%.3f%%", Mismatch.CountSum * 100) << "\n";
1247 if (Unique.NumEntries)
1248 OS << " Percentage of Edge profile only in test_profile: "
1249 << format("%.3f%%", Unique.CountSum * 100) << "\n";
1250 OS << " Edge profile base count sum: " << format("%.0f", Base.CountSum)
1251 << "\n"
1252 << " Edge profile test count sum: " << format("%.0f", Test.CountSum)
1253 << "\n";
1254
1255 for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
1256 if (Base.ValueCounts[I] < 1.0f && Test.ValueCounts[I] < 1.0f)
1257 continue;
1258 char ProfileKindName[20];
1259 switch (I) {
1260 case IPVK_IndirectCallTarget:
1261 strncpy(ProfileKindName, "IndirectCall", 19);
1262 break;
1263 case IPVK_MemOPSize:
1264 strncpy(ProfileKindName, "MemOP", 19);
1265 break;
1266 default:
1267 snprintf(ProfileKindName, 19, "VP[%d]", I);
1268 break;
1269 }
1270 OS << " " << ProfileKindName
1271 << " profile overlap: " << format("%.3f%%", Overlap.ValueCounts[I] * 100)
1272 << "\n";
1273 if (Mismatch.NumEntries)
1274 OS << " Mismatched count percentage (" << ProfileKindName
1275 << "): " << format("%.3f%%", Mismatch.ValueCounts[I] * 100) << "\n";
1276 if (Unique.NumEntries)
1277 OS << " Percentage of " << ProfileKindName
1278 << " profile only in test_profile: "
1279 << format("%.3f%%", Unique.ValueCounts[I] * 100) << "\n";
1280 OS << " " << ProfileKindName
1281 << " profile base count sum: " << format("%.0f", Base.ValueCounts[I])
1282 << "\n"
1283 << " " << ProfileKindName
1284 << " profile test count sum: " << format("%.0f", Test.ValueCounts[I])
1285 << "\n";
1286 }
1287 }
1288
1289 } // end namespace llvm
1290