File: | lib/Transforms/IPO/SampleProfile.cpp |
Warning: | line 1725, column 34 Dereference of null smart pointer 'Reader' of type 'std::unique_ptr' |
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1 | //===- SampleProfile.cpp - Incorporate sample profiles into the IR --------===// | |||
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 implements the SampleProfileLoader transformation. This pass | |||
10 | // reads a profile file generated by a sampling profiler (e.g. Linux Perf - | |||
11 | // http://perf.wiki.kernel.org/) and generates IR metadata to reflect the | |||
12 | // profile information in the given profile. | |||
13 | // | |||
14 | // This pass generates branch weight annotations on the IR: | |||
15 | // | |||
16 | // - prof: Represents branch weights. This annotation is added to branches | |||
17 | // to indicate the weights of each edge coming out of the branch. | |||
18 | // The weight of each edge is the weight of the target block for | |||
19 | // that edge. The weight of a block B is computed as the maximum | |||
20 | // number of samples found in B. | |||
21 | // | |||
22 | //===----------------------------------------------------------------------===// | |||
23 | ||||
24 | #include "llvm/Transforms/IPO/SampleProfile.h" | |||
25 | #include "llvm/ADT/ArrayRef.h" | |||
26 | #include "llvm/ADT/DenseMap.h" | |||
27 | #include "llvm/ADT/DenseSet.h" | |||
28 | #include "llvm/ADT/None.h" | |||
29 | #include "llvm/ADT/SmallPtrSet.h" | |||
30 | #include "llvm/ADT/SmallSet.h" | |||
31 | #include "llvm/ADT/SmallVector.h" | |||
32 | #include "llvm/ADT/StringMap.h" | |||
33 | #include "llvm/ADT/StringRef.h" | |||
34 | #include "llvm/ADT/Twine.h" | |||
35 | #include "llvm/Analysis/AssumptionCache.h" | |||
36 | #include "llvm/Analysis/InlineCost.h" | |||
37 | #include "llvm/Analysis/LoopInfo.h" | |||
38 | #include "llvm/Analysis/OptimizationRemarkEmitter.h" | |||
39 | #include "llvm/Analysis/PostDominators.h" | |||
40 | #include "llvm/Analysis/ProfileSummaryInfo.h" | |||
41 | #include "llvm/Analysis/TargetTransformInfo.h" | |||
42 | #include "llvm/IR/BasicBlock.h" | |||
43 | #include "llvm/IR/CFG.h" | |||
44 | #include "llvm/IR/CallSite.h" | |||
45 | #include "llvm/IR/DebugInfoMetadata.h" | |||
46 | #include "llvm/IR/DebugLoc.h" | |||
47 | #include "llvm/IR/DiagnosticInfo.h" | |||
48 | #include "llvm/IR/Dominators.h" | |||
49 | #include "llvm/IR/Function.h" | |||
50 | #include "llvm/IR/GlobalValue.h" | |||
51 | #include "llvm/IR/InstrTypes.h" | |||
52 | #include "llvm/IR/Instruction.h" | |||
53 | #include "llvm/IR/Instructions.h" | |||
54 | #include "llvm/IR/IntrinsicInst.h" | |||
55 | #include "llvm/IR/LLVMContext.h" | |||
56 | #include "llvm/IR/MDBuilder.h" | |||
57 | #include "llvm/IR/Module.h" | |||
58 | #include "llvm/IR/PassManager.h" | |||
59 | #include "llvm/IR/ValueSymbolTable.h" | |||
60 | #include "llvm/Pass.h" | |||
61 | #include "llvm/ProfileData/InstrProf.h" | |||
62 | #include "llvm/ProfileData/SampleProf.h" | |||
63 | #include "llvm/ProfileData/SampleProfReader.h" | |||
64 | #include "llvm/Support/Casting.h" | |||
65 | #include "llvm/Support/CommandLine.h" | |||
66 | #include "llvm/Support/Debug.h" | |||
67 | #include "llvm/Support/ErrorHandling.h" | |||
68 | #include "llvm/Support/ErrorOr.h" | |||
69 | #include "llvm/Support/GenericDomTree.h" | |||
70 | #include "llvm/Support/raw_ostream.h" | |||
71 | #include "llvm/Transforms/IPO.h" | |||
72 | #include "llvm/Transforms/Instrumentation.h" | |||
73 | #include "llvm/Transforms/Utils/CallPromotionUtils.h" | |||
74 | #include "llvm/Transforms/Utils/Cloning.h" | |||
75 | #include "llvm/Transforms/Utils/MisExpect.h" | |||
76 | #include <algorithm> | |||
77 | #include <cassert> | |||
78 | #include <cstdint> | |||
79 | #include <functional> | |||
80 | #include <limits> | |||
81 | #include <map> | |||
82 | #include <memory> | |||
83 | #include <queue> | |||
84 | #include <string> | |||
85 | #include <system_error> | |||
86 | #include <utility> | |||
87 | #include <vector> | |||
88 | ||||
89 | using namespace llvm; | |||
90 | using namespace sampleprof; | |||
91 | using ProfileCount = Function::ProfileCount; | |||
92 | #define DEBUG_TYPE"sample-profile" "sample-profile" | |||
93 | ||||
94 | // Command line option to specify the file to read samples from. This is | |||
95 | // mainly used for debugging. | |||
96 | static cl::opt<std::string> SampleProfileFile( | |||
97 | "sample-profile-file", cl::init(""), cl::value_desc("filename"), | |||
98 | cl::desc("Profile file loaded by -sample-profile"), cl::Hidden); | |||
99 | ||||
100 | // The named file contains a set of transformations that may have been applied | |||
101 | // to the symbol names between the program from which the sample data was | |||
102 | // collected and the current program's symbols. | |||
103 | static cl::opt<std::string> SampleProfileRemappingFile( | |||
104 | "sample-profile-remapping-file", cl::init(""), cl::value_desc("filename"), | |||
105 | cl::desc("Profile remapping file loaded by -sample-profile"), cl::Hidden); | |||
106 | ||||
107 | static cl::opt<unsigned> SampleProfileMaxPropagateIterations( | |||
108 | "sample-profile-max-propagate-iterations", cl::init(100), | |||
109 | cl::desc("Maximum number of iterations to go through when propagating " | |||
110 | "sample block/edge weights through the CFG.")); | |||
111 | ||||
112 | static cl::opt<unsigned> SampleProfileRecordCoverage( | |||
113 | "sample-profile-check-record-coverage", cl::init(0), cl::value_desc("N"), | |||
114 | cl::desc("Emit a warning if less than N% of records in the input profile " | |||
115 | "are matched to the IR.")); | |||
116 | ||||
117 | static cl::opt<unsigned> SampleProfileSampleCoverage( | |||
118 | "sample-profile-check-sample-coverage", cl::init(0), cl::value_desc("N"), | |||
119 | cl::desc("Emit a warning if less than N% of samples in the input profile " | |||
120 | "are matched to the IR.")); | |||
121 | ||||
122 | static cl::opt<bool> NoWarnSampleUnused( | |||
123 | "no-warn-sample-unused", cl::init(false), cl::Hidden, | |||
124 | cl::desc("Use this option to turn off/on warnings about function with " | |||
125 | "samples but without debug information to use those samples. ")); | |||
126 | ||||
127 | static cl::opt<bool> ProfileSampleAccurate( | |||
128 | "profile-sample-accurate", cl::Hidden, cl::init(false), | |||
129 | cl::desc("If the sample profile is accurate, we will mark all un-sampled " | |||
130 | "callsite and function as having 0 samples. Otherwise, treat " | |||
131 | "un-sampled callsites and functions conservatively as unknown. ")); | |||
132 | ||||
133 | static cl::opt<bool> ProfileAccurateForSymsInList( | |||
134 | "profile-accurate-for-symsinlist", cl::Hidden, cl::ZeroOrMore, | |||
135 | cl::init(true), | |||
136 | cl::desc("For symbols in profile symbol list, regard their profiles to " | |||
137 | "be accurate. It may be overriden by profile-sample-accurate. ")); | |||
138 | ||||
139 | namespace { | |||
140 | ||||
141 | using BlockWeightMap = DenseMap<const BasicBlock *, uint64_t>; | |||
142 | using EquivalenceClassMap = DenseMap<const BasicBlock *, const BasicBlock *>; | |||
143 | using Edge = std::pair<const BasicBlock *, const BasicBlock *>; | |||
144 | using EdgeWeightMap = DenseMap<Edge, uint64_t>; | |||
145 | using BlockEdgeMap = | |||
146 | DenseMap<const BasicBlock *, SmallVector<const BasicBlock *, 8>>; | |||
147 | ||||
148 | class SampleProfileLoader; | |||
149 | ||||
150 | class SampleCoverageTracker { | |||
151 | public: | |||
152 | SampleCoverageTracker(SampleProfileLoader &SPL) : SPLoader(SPL){}; | |||
153 | ||||
154 | bool markSamplesUsed(const FunctionSamples *FS, uint32_t LineOffset, | |||
155 | uint32_t Discriminator, uint64_t Samples); | |||
156 | unsigned computeCoverage(unsigned Used, unsigned Total) const; | |||
157 | unsigned countUsedRecords(const FunctionSamples *FS, | |||
158 | ProfileSummaryInfo *PSI) const; | |||
159 | unsigned countBodyRecords(const FunctionSamples *FS, | |||
160 | ProfileSummaryInfo *PSI) const; | |||
161 | uint64_t getTotalUsedSamples() const { return TotalUsedSamples; } | |||
162 | uint64_t countBodySamples(const FunctionSamples *FS, | |||
163 | ProfileSummaryInfo *PSI) const; | |||
164 | ||||
165 | void clear() { | |||
166 | SampleCoverage.clear(); | |||
167 | TotalUsedSamples = 0; | |||
168 | } | |||
169 | ||||
170 | private: | |||
171 | using BodySampleCoverageMap = std::map<LineLocation, unsigned>; | |||
172 | using FunctionSamplesCoverageMap = | |||
173 | DenseMap<const FunctionSamples *, BodySampleCoverageMap>; | |||
174 | ||||
175 | /// Coverage map for sampling records. | |||
176 | /// | |||
177 | /// This map keeps a record of sampling records that have been matched to | |||
178 | /// an IR instruction. This is used to detect some form of staleness in | |||
179 | /// profiles (see flag -sample-profile-check-coverage). | |||
180 | /// | |||
181 | /// Each entry in the map corresponds to a FunctionSamples instance. This is | |||
182 | /// another map that counts how many times the sample record at the | |||
183 | /// given location has been used. | |||
184 | FunctionSamplesCoverageMap SampleCoverage; | |||
185 | ||||
186 | /// Number of samples used from the profile. | |||
187 | /// | |||
188 | /// When a sampling record is used for the first time, the samples from | |||
189 | /// that record are added to this accumulator. Coverage is later computed | |||
190 | /// based on the total number of samples available in this function and | |||
191 | /// its callsites. | |||
192 | /// | |||
193 | /// Note that this accumulator tracks samples used from a single function | |||
194 | /// and all the inlined callsites. Strictly, we should have a map of counters | |||
195 | /// keyed by FunctionSamples pointers, but these stats are cleared after | |||
196 | /// every function, so we just need to keep a single counter. | |||
197 | uint64_t TotalUsedSamples = 0; | |||
198 | ||||
199 | SampleProfileLoader &SPLoader; | |||
200 | }; | |||
201 | ||||
202 | class GUIDToFuncNameMapper { | |||
203 | public: | |||
204 | GUIDToFuncNameMapper(Module &M, SampleProfileReader &Reader, | |||
205 | DenseMap<uint64_t, StringRef> &GUIDToFuncNameMap) | |||
206 | : CurrentReader(Reader), CurrentModule(M), | |||
207 | CurrentGUIDToFuncNameMap(GUIDToFuncNameMap) { | |||
208 | if (CurrentReader.getFormat() != SPF_Compact_Binary) | |||
209 | return; | |||
210 | ||||
211 | for (const auto &F : CurrentModule) { | |||
212 | StringRef OrigName = F.getName(); | |||
213 | CurrentGUIDToFuncNameMap.insert( | |||
214 | {Function::getGUID(OrigName), OrigName}); | |||
215 | ||||
216 | // Local to global var promotion used by optimization like thinlto | |||
217 | // will rename the var and add suffix like ".llvm.xxx" to the | |||
218 | // original local name. In sample profile, the suffixes of function | |||
219 | // names are all stripped. Since it is possible that the mapper is | |||
220 | // built in post-thin-link phase and var promotion has been done, | |||
221 | // we need to add the substring of function name without the suffix | |||
222 | // into the GUIDToFuncNameMap. | |||
223 | StringRef CanonName = FunctionSamples::getCanonicalFnName(F); | |||
224 | if (CanonName != OrigName) | |||
225 | CurrentGUIDToFuncNameMap.insert( | |||
226 | {Function::getGUID(CanonName), CanonName}); | |||
227 | } | |||
228 | ||||
229 | // Update GUIDToFuncNameMap for each function including inlinees. | |||
230 | SetGUIDToFuncNameMapForAll(&CurrentGUIDToFuncNameMap); | |||
231 | } | |||
232 | ||||
233 | ~GUIDToFuncNameMapper() { | |||
234 | if (CurrentReader.getFormat() != SPF_Compact_Binary) | |||
235 | return; | |||
236 | ||||
237 | CurrentGUIDToFuncNameMap.clear(); | |||
238 | ||||
239 | // Reset GUIDToFuncNameMap for of each function as they're no | |||
240 | // longer valid at this point. | |||
241 | SetGUIDToFuncNameMapForAll(nullptr); | |||
242 | } | |||
243 | ||||
244 | private: | |||
245 | void SetGUIDToFuncNameMapForAll(DenseMap<uint64_t, StringRef> *Map) { | |||
246 | std::queue<FunctionSamples *> FSToUpdate; | |||
247 | for (auto &IFS : CurrentReader.getProfiles()) { | |||
248 | FSToUpdate.push(&IFS.second); | |||
249 | } | |||
250 | ||||
251 | while (!FSToUpdate.empty()) { | |||
252 | FunctionSamples *FS = FSToUpdate.front(); | |||
253 | FSToUpdate.pop(); | |||
254 | FS->GUIDToFuncNameMap = Map; | |||
255 | for (const auto &ICS : FS->getCallsiteSamples()) { | |||
256 | const FunctionSamplesMap &FSMap = ICS.second; | |||
257 | for (auto &IFS : FSMap) { | |||
258 | FunctionSamples &FS = const_cast<FunctionSamples &>(IFS.second); | |||
259 | FSToUpdate.push(&FS); | |||
260 | } | |||
261 | } | |||
262 | } | |||
263 | } | |||
264 | ||||
265 | SampleProfileReader &CurrentReader; | |||
266 | Module &CurrentModule; | |||
267 | DenseMap<uint64_t, StringRef> &CurrentGUIDToFuncNameMap; | |||
268 | }; | |||
269 | ||||
270 | /// Sample profile pass. | |||
271 | /// | |||
272 | /// This pass reads profile data from the file specified by | |||
273 | /// -sample-profile-file and annotates every affected function with the | |||
274 | /// profile information found in that file. | |||
275 | class SampleProfileLoader { | |||
276 | public: | |||
277 | SampleProfileLoader( | |||
278 | StringRef Name, StringRef RemapName, bool IsThinLTOPreLink, | |||
279 | std::function<AssumptionCache &(Function &)> GetAssumptionCache, | |||
280 | std::function<TargetTransformInfo &(Function &)> GetTargetTransformInfo) | |||
281 | : GetAC(std::move(GetAssumptionCache)), | |||
282 | GetTTI(std::move(GetTargetTransformInfo)), CoverageTracker(*this), | |||
283 | Filename(Name), RemappingFilename(RemapName), | |||
284 | IsThinLTOPreLink(IsThinLTOPreLink) {} | |||
285 | ||||
286 | bool doInitialization(Module &M); | |||
287 | bool runOnModule(Module &M, ModuleAnalysisManager *AM, | |||
288 | ProfileSummaryInfo *_PSI); | |||
289 | ||||
290 | void dump() { Reader->dump(); } | |||
291 | ||||
292 | protected: | |||
293 | friend class SampleCoverageTracker; | |||
294 | ||||
295 | bool runOnFunction(Function &F, ModuleAnalysisManager *AM); | |||
296 | unsigned getFunctionLoc(Function &F); | |||
297 | bool emitAnnotations(Function &F); | |||
298 | ErrorOr<uint64_t> getInstWeight(const Instruction &I); | |||
299 | ErrorOr<uint64_t> getBlockWeight(const BasicBlock *BB); | |||
300 | const FunctionSamples *findCalleeFunctionSamples(const Instruction &I) const; | |||
301 | std::vector<const FunctionSamples *> | |||
302 | findIndirectCallFunctionSamples(const Instruction &I, uint64_t &Sum) const; | |||
303 | mutable DenseMap<const DILocation *, const FunctionSamples *> DILocation2SampleMap; | |||
304 | const FunctionSamples *findFunctionSamples(const Instruction &I) const; | |||
305 | bool inlineCallInstruction(Instruction *I); | |||
306 | bool inlineHotFunctions(Function &F, | |||
307 | DenseSet<GlobalValue::GUID> &InlinedGUIDs); | |||
308 | void printEdgeWeight(raw_ostream &OS, Edge E); | |||
309 | void printBlockWeight(raw_ostream &OS, const BasicBlock *BB) const; | |||
310 | void printBlockEquivalence(raw_ostream &OS, const BasicBlock *BB); | |||
311 | bool computeBlockWeights(Function &F); | |||
312 | void findEquivalenceClasses(Function &F); | |||
313 | template <bool IsPostDom> | |||
314 | void findEquivalencesFor(BasicBlock *BB1, ArrayRef<BasicBlock *> Descendants, | |||
315 | DominatorTreeBase<BasicBlock, IsPostDom> *DomTree); | |||
316 | ||||
317 | void propagateWeights(Function &F); | |||
318 | uint64_t visitEdge(Edge E, unsigned *NumUnknownEdges, Edge *UnknownEdge); | |||
319 | void buildEdges(Function &F); | |||
320 | bool propagateThroughEdges(Function &F, bool UpdateBlockCount); | |||
321 | void computeDominanceAndLoopInfo(Function &F); | |||
322 | void clearFunctionData(); | |||
323 | bool callsiteIsHot(const FunctionSamples *CallsiteFS, | |||
324 | ProfileSummaryInfo *PSI); | |||
325 | ||||
326 | /// Map basic blocks to their computed weights. | |||
327 | /// | |||
328 | /// The weight of a basic block is defined to be the maximum | |||
329 | /// of all the instruction weights in that block. | |||
330 | BlockWeightMap BlockWeights; | |||
331 | ||||
332 | /// Map edges to their computed weights. | |||
333 | /// | |||
334 | /// Edge weights are computed by propagating basic block weights in | |||
335 | /// SampleProfile::propagateWeights. | |||
336 | EdgeWeightMap EdgeWeights; | |||
337 | ||||
338 | /// Set of visited blocks during propagation. | |||
339 | SmallPtrSet<const BasicBlock *, 32> VisitedBlocks; | |||
340 | ||||
341 | /// Set of visited edges during propagation. | |||
342 | SmallSet<Edge, 32> VisitedEdges; | |||
343 | ||||
344 | /// Equivalence classes for block weights. | |||
345 | /// | |||
346 | /// Two blocks BB1 and BB2 are in the same equivalence class if they | |||
347 | /// dominate and post-dominate each other, and they are in the same loop | |||
348 | /// nest. When this happens, the two blocks are guaranteed to execute | |||
349 | /// the same number of times. | |||
350 | EquivalenceClassMap EquivalenceClass; | |||
351 | ||||
352 | /// Map from function name to Function *. Used to find the function from | |||
353 | /// the function name. If the function name contains suffix, additional | |||
354 | /// entry is added to map from the stripped name to the function if there | |||
355 | /// is one-to-one mapping. | |||
356 | StringMap<Function *> SymbolMap; | |||
357 | ||||
358 | /// Dominance, post-dominance and loop information. | |||
359 | std::unique_ptr<DominatorTree> DT; | |||
360 | std::unique_ptr<PostDominatorTree> PDT; | |||
361 | std::unique_ptr<LoopInfo> LI; | |||
362 | ||||
363 | std::function<AssumptionCache &(Function &)> GetAC; | |||
364 | std::function<TargetTransformInfo &(Function &)> GetTTI; | |||
365 | ||||
366 | /// Predecessors for each basic block in the CFG. | |||
367 | BlockEdgeMap Predecessors; | |||
368 | ||||
369 | /// Successors for each basic block in the CFG. | |||
370 | BlockEdgeMap Successors; | |||
371 | ||||
372 | SampleCoverageTracker CoverageTracker; | |||
373 | ||||
374 | /// Profile reader object. | |||
375 | std::unique_ptr<SampleProfileReader> Reader; | |||
376 | ||||
377 | /// Samples collected for the body of this function. | |||
378 | FunctionSamples *Samples = nullptr; | |||
379 | ||||
380 | /// Name of the profile file to load. | |||
381 | std::string Filename; | |||
382 | ||||
383 | /// Name of the profile remapping file to load. | |||
384 | std::string RemappingFilename; | |||
385 | ||||
386 | /// Flag indicating whether the profile input loaded successfully. | |||
387 | bool ProfileIsValid = false; | |||
388 | ||||
389 | /// Flag indicating if the pass is invoked in ThinLTO compile phase. | |||
390 | /// | |||
391 | /// In this phase, in annotation, we should not promote indirect calls. | |||
392 | /// Instead, we will mark GUIDs that needs to be annotated to the function. | |||
393 | bool IsThinLTOPreLink; | |||
394 | ||||
395 | /// Profile Summary Info computed from sample profile. | |||
396 | ProfileSummaryInfo *PSI = nullptr; | |||
397 | ||||
398 | /// Profle Symbol list tells whether a function name appears in the binary | |||
399 | /// used to generate the current profile. | |||
400 | std::unique_ptr<ProfileSymbolList> PSL; | |||
401 | ||||
402 | /// Total number of samples collected in this profile. | |||
403 | /// | |||
404 | /// This is the sum of all the samples collected in all the functions executed | |||
405 | /// at runtime. | |||
406 | uint64_t TotalCollectedSamples = 0; | |||
407 | ||||
408 | /// Optimization Remark Emitter used to emit diagnostic remarks. | |||
409 | OptimizationRemarkEmitter *ORE = nullptr; | |||
410 | ||||
411 | // Information recorded when we declined to inline a call site | |||
412 | // because we have determined it is too cold is accumulated for | |||
413 | // each callee function. Initially this is just the entry count. | |||
414 | struct NotInlinedProfileInfo { | |||
415 | uint64_t entryCount; | |||
416 | }; | |||
417 | DenseMap<Function *, NotInlinedProfileInfo> notInlinedCallInfo; | |||
418 | ||||
419 | // GUIDToFuncNameMap saves the mapping from GUID to the symbol name, for | |||
420 | // all the function symbols defined or declared in current module. | |||
421 | DenseMap<uint64_t, StringRef> GUIDToFuncNameMap; | |||
422 | ||||
423 | // All the Names used in FunctionSamples including outline function | |||
424 | // names, inline instance names and call target names. | |||
425 | StringSet<> NamesInProfile; | |||
426 | ||||
427 | // For symbol in profile symbol list, whether to regard their profiles | |||
428 | // to be accurate. It is mainly decided by existance of profile symbol | |||
429 | // list and -profile-accurate-for-symsinlist flag, but it can be | |||
430 | // overriden by -profile-sample-accurate or profile-sample-accurate | |||
431 | // attribute. | |||
432 | bool ProfAccForSymsInList; | |||
433 | }; | |||
434 | ||||
435 | class SampleProfileLoaderLegacyPass : public ModulePass { | |||
436 | public: | |||
437 | // Class identification, replacement for typeinfo | |||
438 | static char ID; | |||
439 | ||||
440 | SampleProfileLoaderLegacyPass(StringRef Name = SampleProfileFile, | |||
441 | bool IsThinLTOPreLink = false) | |||
442 | : ModulePass(ID), | |||
443 | SampleLoader(Name, SampleProfileRemappingFile, IsThinLTOPreLink, | |||
444 | [&](Function &F) -> AssumptionCache & { | |||
445 | return ACT->getAssumptionCache(F); | |||
446 | }, | |||
447 | [&](Function &F) -> TargetTransformInfo & { | |||
448 | return TTIWP->getTTI(F); | |||
449 | }) { | |||
450 | initializeSampleProfileLoaderLegacyPassPass( | |||
451 | *PassRegistry::getPassRegistry()); | |||
452 | } | |||
453 | ||||
454 | void dump() { SampleLoader.dump(); } | |||
455 | ||||
456 | bool doInitialization(Module &M) override { | |||
457 | return SampleLoader.doInitialization(M); | |||
458 | } | |||
459 | ||||
460 | StringRef getPassName() const override { return "Sample profile pass"; } | |||
461 | bool runOnModule(Module &M) override; | |||
462 | ||||
463 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
464 | AU.addRequired<AssumptionCacheTracker>(); | |||
465 | AU.addRequired<TargetTransformInfoWrapperPass>(); | |||
466 | AU.addRequired<ProfileSummaryInfoWrapperPass>(); | |||
467 | } | |||
468 | ||||
469 | private: | |||
470 | SampleProfileLoader SampleLoader; | |||
471 | AssumptionCacheTracker *ACT = nullptr; | |||
472 | TargetTransformInfoWrapperPass *TTIWP = nullptr; | |||
473 | }; | |||
474 | ||||
475 | } // end anonymous namespace | |||
476 | ||||
477 | /// Return true if the given callsite is hot wrt to hot cutoff threshold. | |||
478 | /// | |||
479 | /// Functions that were inlined in the original binary will be represented | |||
480 | /// in the inline stack in the sample profile. If the profile shows that | |||
481 | /// the original inline decision was "good" (i.e., the callsite is executed | |||
482 | /// frequently), then we will recreate the inline decision and apply the | |||
483 | /// profile from the inlined callsite. | |||
484 | /// | |||
485 | /// To decide whether an inlined callsite is hot, we compare the callsite | |||
486 | /// sample count with the hot cutoff computed by ProfileSummaryInfo, it is | |||
487 | /// regarded as hot if the count is above the cutoff value. | |||
488 | /// | |||
489 | /// When ProfileAccurateForSymsInList is enabled and profile symbol list | |||
490 | /// is present, functions in the profile symbol list but without profile will | |||
491 | /// be regarded as cold and much less inlining will happen in CGSCC inlining | |||
492 | /// pass, so we tend to lower the hot criteria here to allow more early | |||
493 | /// inlining to happen for warm callsites and it is helpful for performance. | |||
494 | bool SampleProfileLoader::callsiteIsHot(const FunctionSamples *CallsiteFS, | |||
495 | ProfileSummaryInfo *PSI) { | |||
496 | if (!CallsiteFS) | |||
497 | return false; // The callsite was not inlined in the original binary. | |||
498 | ||||
499 | assert(PSI && "PSI is expected to be non null")((PSI && "PSI is expected to be non null") ? static_cast <void> (0) : __assert_fail ("PSI && \"PSI is expected to be non null\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 499, __PRETTY_FUNCTION__)); | |||
500 | uint64_t CallsiteTotalSamples = CallsiteFS->getTotalSamples(); | |||
501 | if (ProfAccForSymsInList) | |||
502 | return !PSI->isColdCount(CallsiteTotalSamples); | |||
503 | else | |||
504 | return PSI->isHotCount(CallsiteTotalSamples); | |||
505 | } | |||
506 | ||||
507 | /// Mark as used the sample record for the given function samples at | |||
508 | /// (LineOffset, Discriminator). | |||
509 | /// | |||
510 | /// \returns true if this is the first time we mark the given record. | |||
511 | bool SampleCoverageTracker::markSamplesUsed(const FunctionSamples *FS, | |||
512 | uint32_t LineOffset, | |||
513 | uint32_t Discriminator, | |||
514 | uint64_t Samples) { | |||
515 | LineLocation Loc(LineOffset, Discriminator); | |||
516 | unsigned &Count = SampleCoverage[FS][Loc]; | |||
517 | bool FirstTime = (++Count == 1); | |||
518 | if (FirstTime) | |||
519 | TotalUsedSamples += Samples; | |||
520 | return FirstTime; | |||
521 | } | |||
522 | ||||
523 | /// Return the number of sample records that were applied from this profile. | |||
524 | /// | |||
525 | /// This count does not include records from cold inlined callsites. | |||
526 | unsigned | |||
527 | SampleCoverageTracker::countUsedRecords(const FunctionSamples *FS, | |||
528 | ProfileSummaryInfo *PSI) const { | |||
529 | auto I = SampleCoverage.find(FS); | |||
530 | ||||
531 | // The size of the coverage map for FS represents the number of records | |||
532 | // that were marked used at least once. | |||
533 | unsigned Count = (I != SampleCoverage.end()) ? I->second.size() : 0; | |||
534 | ||||
535 | // If there are inlined callsites in this function, count the samples found | |||
536 | // in the respective bodies. However, do not bother counting callees with 0 | |||
537 | // total samples, these are callees that were never invoked at runtime. | |||
538 | for (const auto &I : FS->getCallsiteSamples()) | |||
539 | for (const auto &J : I.second) { | |||
540 | const FunctionSamples *CalleeSamples = &J.second; | |||
541 | if (SPLoader.callsiteIsHot(CalleeSamples, PSI)) | |||
542 | Count += countUsedRecords(CalleeSamples, PSI); | |||
543 | } | |||
544 | ||||
545 | return Count; | |||
546 | } | |||
547 | ||||
548 | /// Return the number of sample records in the body of this profile. | |||
549 | /// | |||
550 | /// This count does not include records from cold inlined callsites. | |||
551 | unsigned | |||
552 | SampleCoverageTracker::countBodyRecords(const FunctionSamples *FS, | |||
553 | ProfileSummaryInfo *PSI) const { | |||
554 | unsigned Count = FS->getBodySamples().size(); | |||
555 | ||||
556 | // Only count records in hot callsites. | |||
557 | for (const auto &I : FS->getCallsiteSamples()) | |||
558 | for (const auto &J : I.second) { | |||
559 | const FunctionSamples *CalleeSamples = &J.second; | |||
560 | if (SPLoader.callsiteIsHot(CalleeSamples, PSI)) | |||
561 | Count += countBodyRecords(CalleeSamples, PSI); | |||
562 | } | |||
563 | ||||
564 | return Count; | |||
565 | } | |||
566 | ||||
567 | /// Return the number of samples collected in the body of this profile. | |||
568 | /// | |||
569 | /// This count does not include samples from cold inlined callsites. | |||
570 | uint64_t | |||
571 | SampleCoverageTracker::countBodySamples(const FunctionSamples *FS, | |||
572 | ProfileSummaryInfo *PSI) const { | |||
573 | uint64_t Total = 0; | |||
574 | for (const auto &I : FS->getBodySamples()) | |||
575 | Total += I.second.getSamples(); | |||
576 | ||||
577 | // Only count samples in hot callsites. | |||
578 | for (const auto &I : FS->getCallsiteSamples()) | |||
579 | for (const auto &J : I.second) { | |||
580 | const FunctionSamples *CalleeSamples = &J.second; | |||
581 | if (SPLoader.callsiteIsHot(CalleeSamples, PSI)) | |||
582 | Total += countBodySamples(CalleeSamples, PSI); | |||
583 | } | |||
584 | ||||
585 | return Total; | |||
586 | } | |||
587 | ||||
588 | /// Return the fraction of sample records used in this profile. | |||
589 | /// | |||
590 | /// The returned value is an unsigned integer in the range 0-100 indicating | |||
591 | /// the percentage of sample records that were used while applying this | |||
592 | /// profile to the associated function. | |||
593 | unsigned SampleCoverageTracker::computeCoverage(unsigned Used, | |||
594 | unsigned Total) const { | |||
595 | assert(Used <= Total &&((Used <= Total && "number of used records cannot exceed the total number of records" ) ? static_cast<void> (0) : __assert_fail ("Used <= Total && \"number of used records cannot exceed the total number of records\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 596, __PRETTY_FUNCTION__)) | |||
596 | "number of used records cannot exceed the total number of records")((Used <= Total && "number of used records cannot exceed the total number of records" ) ? static_cast<void> (0) : __assert_fail ("Used <= Total && \"number of used records cannot exceed the total number of records\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 596, __PRETTY_FUNCTION__)); | |||
597 | return Total > 0 ? Used * 100 / Total : 100; | |||
598 | } | |||
599 | ||||
600 | /// Clear all the per-function data used to load samples and propagate weights. | |||
601 | void SampleProfileLoader::clearFunctionData() { | |||
602 | BlockWeights.clear(); | |||
603 | EdgeWeights.clear(); | |||
604 | VisitedBlocks.clear(); | |||
605 | VisitedEdges.clear(); | |||
606 | EquivalenceClass.clear(); | |||
607 | DT = nullptr; | |||
608 | PDT = nullptr; | |||
609 | LI = nullptr; | |||
610 | Predecessors.clear(); | |||
611 | Successors.clear(); | |||
612 | CoverageTracker.clear(); | |||
613 | } | |||
614 | ||||
615 | #ifndef NDEBUG | |||
616 | /// Print the weight of edge \p E on stream \p OS. | |||
617 | /// | |||
618 | /// \param OS Stream to emit the output to. | |||
619 | /// \param E Edge to print. | |||
620 | void SampleProfileLoader::printEdgeWeight(raw_ostream &OS, Edge E) { | |||
621 | OS << "weight[" << E.first->getName() << "->" << E.second->getName() | |||
622 | << "]: " << EdgeWeights[E] << "\n"; | |||
623 | } | |||
624 | ||||
625 | /// Print the equivalence class of block \p BB on stream \p OS. | |||
626 | /// | |||
627 | /// \param OS Stream to emit the output to. | |||
628 | /// \param BB Block to print. | |||
629 | void SampleProfileLoader::printBlockEquivalence(raw_ostream &OS, | |||
630 | const BasicBlock *BB) { | |||
631 | const BasicBlock *Equiv = EquivalenceClass[BB]; | |||
632 | OS << "equivalence[" << BB->getName() | |||
633 | << "]: " << ((Equiv) ? EquivalenceClass[BB]->getName() : "NONE") << "\n"; | |||
634 | } | |||
635 | ||||
636 | /// Print the weight of block \p BB on stream \p OS. | |||
637 | /// | |||
638 | /// \param OS Stream to emit the output to. | |||
639 | /// \param BB Block to print. | |||
640 | void SampleProfileLoader::printBlockWeight(raw_ostream &OS, | |||
641 | const BasicBlock *BB) const { | |||
642 | const auto &I = BlockWeights.find(BB); | |||
643 | uint64_t W = (I == BlockWeights.end() ? 0 : I->second); | |||
644 | OS << "weight[" << BB->getName() << "]: " << W << "\n"; | |||
645 | } | |||
646 | #endif | |||
647 | ||||
648 | /// Get the weight for an instruction. | |||
649 | /// | |||
650 | /// The "weight" of an instruction \p Inst is the number of samples | |||
651 | /// collected on that instruction at runtime. To retrieve it, we | |||
652 | /// need to compute the line number of \p Inst relative to the start of its | |||
653 | /// function. We use HeaderLineno to compute the offset. We then | |||
654 | /// look up the samples collected for \p Inst using BodySamples. | |||
655 | /// | |||
656 | /// \param Inst Instruction to query. | |||
657 | /// | |||
658 | /// \returns the weight of \p Inst. | |||
659 | ErrorOr<uint64_t> SampleProfileLoader::getInstWeight(const Instruction &Inst) { | |||
660 | const DebugLoc &DLoc = Inst.getDebugLoc(); | |||
661 | if (!DLoc) | |||
662 | return std::error_code(); | |||
663 | ||||
664 | const FunctionSamples *FS = findFunctionSamples(Inst); | |||
665 | if (!FS) | |||
666 | return std::error_code(); | |||
667 | ||||
668 | // Ignore all intrinsics, phinodes and branch instructions. | |||
669 | // Branch and phinodes instruction usually contains debug info from sources outside of | |||
670 | // the residing basic block, thus we ignore them during annotation. | |||
671 | if (isa<BranchInst>(Inst) || isa<IntrinsicInst>(Inst) || isa<PHINode>(Inst)) | |||
672 | return std::error_code(); | |||
673 | ||||
674 | // If a direct call/invoke instruction is inlined in profile | |||
675 | // (findCalleeFunctionSamples returns non-empty result), but not inlined here, | |||
676 | // it means that the inlined callsite has no sample, thus the call | |||
677 | // instruction should have 0 count. | |||
678 | if ((isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) && | |||
679 | !ImmutableCallSite(&Inst).isIndirectCall() && | |||
680 | findCalleeFunctionSamples(Inst)) | |||
681 | return 0; | |||
682 | ||||
683 | const DILocation *DIL = DLoc; | |||
684 | uint32_t LineOffset = FunctionSamples::getOffset(DIL); | |||
685 | uint32_t Discriminator = DIL->getBaseDiscriminator(); | |||
686 | ErrorOr<uint64_t> R = FS->findSamplesAt(LineOffset, Discriminator); | |||
687 | if (R) { | |||
688 | bool FirstMark = | |||
689 | CoverageTracker.markSamplesUsed(FS, LineOffset, Discriminator, R.get()); | |||
690 | if (FirstMark) { | |||
691 | ORE->emit([&]() { | |||
692 | OptimizationRemarkAnalysis Remark(DEBUG_TYPE"sample-profile", "AppliedSamples", &Inst); | |||
693 | Remark << "Applied " << ore::NV("NumSamples", *R); | |||
694 | Remark << " samples from profile (offset: "; | |||
695 | Remark << ore::NV("LineOffset", LineOffset); | |||
696 | if (Discriminator) { | |||
697 | Remark << "."; | |||
698 | Remark << ore::NV("Discriminator", Discriminator); | |||
699 | } | |||
700 | Remark << ")"; | |||
701 | return Remark; | |||
702 | }); | |||
703 | } | |||
704 | LLVM_DEBUG(dbgs() << " " << DLoc.getLine() << "."do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << " " << DLoc.getLine () << "." << DIL->getBaseDiscriminator() << ":" << Inst << " (line offset: " << LineOffset << "." << DIL->getBaseDiscriminator() << " - weight: " << R.get() << ")\n"; } } while (false ) | |||
705 | << DIL->getBaseDiscriminator() << ":" << Instdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << " " << DLoc.getLine () << "." << DIL->getBaseDiscriminator() << ":" << Inst << " (line offset: " << LineOffset << "." << DIL->getBaseDiscriminator() << " - weight: " << R.get() << ")\n"; } } while (false ) | |||
706 | << " (line offset: " << LineOffset << "."do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << " " << DLoc.getLine () << "." << DIL->getBaseDiscriminator() << ":" << Inst << " (line offset: " << LineOffset << "." << DIL->getBaseDiscriminator() << " - weight: " << R.get() << ")\n"; } } while (false ) | |||
707 | << DIL->getBaseDiscriminator() << " - weight: " << R.get()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << " " << DLoc.getLine () << "." << DIL->getBaseDiscriminator() << ":" << Inst << " (line offset: " << LineOffset << "." << DIL->getBaseDiscriminator() << " - weight: " << R.get() << ")\n"; } } while (false ) | |||
708 | << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << " " << DLoc.getLine () << "." << DIL->getBaseDiscriminator() << ":" << Inst << " (line offset: " << LineOffset << "." << DIL->getBaseDiscriminator() << " - weight: " << R.get() << ")\n"; } } while (false ); | |||
709 | } | |||
710 | return R; | |||
711 | } | |||
712 | ||||
713 | /// Compute the weight of a basic block. | |||
714 | /// | |||
715 | /// The weight of basic block \p BB is the maximum weight of all the | |||
716 | /// instructions in BB. | |||
717 | /// | |||
718 | /// \param BB The basic block to query. | |||
719 | /// | |||
720 | /// \returns the weight for \p BB. | |||
721 | ErrorOr<uint64_t> SampleProfileLoader::getBlockWeight(const BasicBlock *BB) { | |||
722 | uint64_t Max = 0; | |||
723 | bool HasWeight = false; | |||
724 | for (auto &I : BB->getInstList()) { | |||
725 | const ErrorOr<uint64_t> &R = getInstWeight(I); | |||
726 | if (R) { | |||
727 | Max = std::max(Max, R.get()); | |||
728 | HasWeight = true; | |||
729 | } | |||
730 | } | |||
731 | return HasWeight ? ErrorOr<uint64_t>(Max) : std::error_code(); | |||
732 | } | |||
733 | ||||
734 | /// Compute and store the weights of every basic block. | |||
735 | /// | |||
736 | /// This populates the BlockWeights map by computing | |||
737 | /// the weights of every basic block in the CFG. | |||
738 | /// | |||
739 | /// \param F The function to query. | |||
740 | bool SampleProfileLoader::computeBlockWeights(Function &F) { | |||
741 | bool Changed = false; | |||
742 | LLVM_DEBUG(dbgs() << "Block weights\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Block weights\n"; } } while (false); | |||
743 | for (const auto &BB : F) { | |||
744 | ErrorOr<uint64_t> Weight = getBlockWeight(&BB); | |||
745 | if (Weight) { | |||
746 | BlockWeights[&BB] = Weight.get(); | |||
747 | VisitedBlocks.insert(&BB); | |||
748 | Changed = true; | |||
749 | } | |||
750 | LLVM_DEBUG(printBlockWeight(dbgs(), &BB))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { printBlockWeight(dbgs(), &BB); } } while (false); | |||
751 | } | |||
752 | ||||
753 | return Changed; | |||
754 | } | |||
755 | ||||
756 | /// Get the FunctionSamples for a call instruction. | |||
757 | /// | |||
758 | /// The FunctionSamples of a call/invoke instruction \p Inst is the inlined | |||
759 | /// instance in which that call instruction is calling to. It contains | |||
760 | /// all samples that resides in the inlined instance. We first find the | |||
761 | /// inlined instance in which the call instruction is from, then we | |||
762 | /// traverse its children to find the callsite with the matching | |||
763 | /// location. | |||
764 | /// | |||
765 | /// \param Inst Call/Invoke instruction to query. | |||
766 | /// | |||
767 | /// \returns The FunctionSamples pointer to the inlined instance. | |||
768 | const FunctionSamples * | |||
769 | SampleProfileLoader::findCalleeFunctionSamples(const Instruction &Inst) const { | |||
770 | const DILocation *DIL = Inst.getDebugLoc(); | |||
771 | if (!DIL) { | |||
772 | return nullptr; | |||
773 | } | |||
774 | ||||
775 | StringRef CalleeName; | |||
776 | if (const CallInst *CI = dyn_cast<CallInst>(&Inst)) | |||
777 | if (Function *Callee = CI->getCalledFunction()) | |||
778 | CalleeName = Callee->getName(); | |||
779 | ||||
780 | const FunctionSamples *FS = findFunctionSamples(Inst); | |||
781 | if (FS == nullptr) | |||
782 | return nullptr; | |||
783 | ||||
784 | return FS->findFunctionSamplesAt(LineLocation(FunctionSamples::getOffset(DIL), | |||
785 | DIL->getBaseDiscriminator()), | |||
786 | CalleeName); | |||
787 | } | |||
788 | ||||
789 | /// Returns a vector of FunctionSamples that are the indirect call targets | |||
790 | /// of \p Inst. The vector is sorted by the total number of samples. Stores | |||
791 | /// the total call count of the indirect call in \p Sum. | |||
792 | std::vector<const FunctionSamples *> | |||
793 | SampleProfileLoader::findIndirectCallFunctionSamples( | |||
794 | const Instruction &Inst, uint64_t &Sum) const { | |||
795 | const DILocation *DIL = Inst.getDebugLoc(); | |||
796 | std::vector<const FunctionSamples *> R; | |||
797 | ||||
798 | if (!DIL) { | |||
799 | return R; | |||
800 | } | |||
801 | ||||
802 | const FunctionSamples *FS = findFunctionSamples(Inst); | |||
803 | if (FS == nullptr) | |||
804 | return R; | |||
805 | ||||
806 | uint32_t LineOffset = FunctionSamples::getOffset(DIL); | |||
807 | uint32_t Discriminator = DIL->getBaseDiscriminator(); | |||
808 | ||||
809 | auto T = FS->findCallTargetMapAt(LineOffset, Discriminator); | |||
810 | Sum = 0; | |||
811 | if (T) | |||
812 | for (const auto &T_C : T.get()) | |||
813 | Sum += T_C.second; | |||
814 | if (const FunctionSamplesMap *M = FS->findFunctionSamplesMapAt(LineLocation( | |||
815 | FunctionSamples::getOffset(DIL), DIL->getBaseDiscriminator()))) { | |||
816 | if (M->empty()) | |||
817 | return R; | |||
818 | for (const auto &NameFS : *M) { | |||
819 | Sum += NameFS.second.getEntrySamples(); | |||
820 | R.push_back(&NameFS.second); | |||
821 | } | |||
822 | llvm::sort(R, [](const FunctionSamples *L, const FunctionSamples *R) { | |||
823 | if (L->getEntrySamples() != R->getEntrySamples()) | |||
824 | return L->getEntrySamples() > R->getEntrySamples(); | |||
825 | return FunctionSamples::getGUID(L->getName()) < | |||
826 | FunctionSamples::getGUID(R->getName()); | |||
827 | }); | |||
828 | } | |||
829 | return R; | |||
830 | } | |||
831 | ||||
832 | /// Get the FunctionSamples for an instruction. | |||
833 | /// | |||
834 | /// The FunctionSamples of an instruction \p Inst is the inlined instance | |||
835 | /// in which that instruction is coming from. We traverse the inline stack | |||
836 | /// of that instruction, and match it with the tree nodes in the profile. | |||
837 | /// | |||
838 | /// \param Inst Instruction to query. | |||
839 | /// | |||
840 | /// \returns the FunctionSamples pointer to the inlined instance. | |||
841 | const FunctionSamples * | |||
842 | SampleProfileLoader::findFunctionSamples(const Instruction &Inst) const { | |||
843 | const DILocation *DIL = Inst.getDebugLoc(); | |||
844 | if (!DIL) | |||
845 | return Samples; | |||
846 | ||||
847 | auto it = DILocation2SampleMap.try_emplace(DIL,nullptr); | |||
848 | if (it.second) | |||
849 | it.first->second = Samples->findFunctionSamples(DIL); | |||
850 | return it.first->second; | |||
851 | } | |||
852 | ||||
853 | bool SampleProfileLoader::inlineCallInstruction(Instruction *I) { | |||
854 | assert(isa<CallInst>(I) || isa<InvokeInst>(I))((isa<CallInst>(I) || isa<InvokeInst>(I)) ? static_cast <void> (0) : __assert_fail ("isa<CallInst>(I) || isa<InvokeInst>(I)" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 854, __PRETTY_FUNCTION__)); | |||
855 | CallSite CS(I); | |||
856 | Function *CalledFunction = CS.getCalledFunction(); | |||
857 | assert(CalledFunction)((CalledFunction) ? static_cast<void> (0) : __assert_fail ("CalledFunction", "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 857, __PRETTY_FUNCTION__)); | |||
858 | DebugLoc DLoc = I->getDebugLoc(); | |||
859 | BasicBlock *BB = I->getParent(); | |||
860 | InlineParams Params = getInlineParams(); | |||
861 | Params.ComputeFullInlineCost = true; | |||
862 | // Checks if there is anything in the reachable portion of the callee at | |||
863 | // this callsite that makes this inlining potentially illegal. Need to | |||
864 | // set ComputeFullInlineCost, otherwise getInlineCost may return early | |||
865 | // when cost exceeds threshold without checking all IRs in the callee. | |||
866 | // The acutal cost does not matter because we only checks isNever() to | |||
867 | // see if it is legal to inline the callsite. | |||
868 | InlineCost Cost = | |||
869 | getInlineCost(cast<CallBase>(*I), Params, GetTTI(*CalledFunction), GetAC, | |||
870 | None, nullptr, nullptr); | |||
871 | if (Cost.isNever()) { | |||
872 | ORE->emit(OptimizationRemark(DEBUG_TYPE"sample-profile", "Not inline", DLoc, BB) | |||
873 | << "incompatible inlining"); | |||
874 | return false; | |||
875 | } | |||
876 | InlineFunctionInfo IFI(nullptr, &GetAC); | |||
877 | if (InlineFunction(CS, IFI)) { | |||
878 | // The call to InlineFunction erases I, so we can't pass it here. | |||
879 | ORE->emit(OptimizationRemark(DEBUG_TYPE"sample-profile", "HotInline", DLoc, BB) | |||
880 | << "inlined hot callee '" << ore::NV("Callee", CalledFunction) | |||
881 | << "' into '" << ore::NV("Caller", BB->getParent()) << "'"); | |||
882 | return true; | |||
883 | } | |||
884 | return false; | |||
885 | } | |||
886 | ||||
887 | /// Iteratively inline hot callsites of a function. | |||
888 | /// | |||
889 | /// Iteratively traverse all callsites of the function \p F, and find if | |||
890 | /// the corresponding inlined instance exists and is hot in profile. If | |||
891 | /// it is hot enough, inline the callsites and adds new callsites of the | |||
892 | /// callee into the caller. If the call is an indirect call, first promote | |||
893 | /// it to direct call. Each indirect call is limited with a single target. | |||
894 | /// | |||
895 | /// \param F function to perform iterative inlining. | |||
896 | /// \param InlinedGUIDs a set to be updated to include all GUIDs that are | |||
897 | /// inlined in the profiled binary. | |||
898 | /// | |||
899 | /// \returns True if there is any inline happened. | |||
900 | bool SampleProfileLoader::inlineHotFunctions( | |||
901 | Function &F, DenseSet<GlobalValue::GUID> &InlinedGUIDs) { | |||
902 | DenseSet<Instruction *> PromotedInsns; | |||
903 | ||||
904 | // ProfAccForSymsInList is used in callsiteIsHot. The assertion makes sure | |||
905 | // Profile symbol list is ignored when profile-sample-accurate is on. | |||
906 | assert((!ProfAccForSymsInList ||(((!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute("profile-sample-accurate"))) && "ProfAccForSymsInList should be false when profile-sample-accurate " "is enabled") ? static_cast<void> (0) : __assert_fail ( "(!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute(\"profile-sample-accurate\"))) && \"ProfAccForSymsInList should be false when profile-sample-accurate \" \"is enabled\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 910, __PRETTY_FUNCTION__)) | |||
907 | (!ProfileSampleAccurate &&(((!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute("profile-sample-accurate"))) && "ProfAccForSymsInList should be false when profile-sample-accurate " "is enabled") ? static_cast<void> (0) : __assert_fail ( "(!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute(\"profile-sample-accurate\"))) && \"ProfAccForSymsInList should be false when profile-sample-accurate \" \"is enabled\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 910, __PRETTY_FUNCTION__)) | |||
908 | !F.hasFnAttribute("profile-sample-accurate"))) &&(((!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute("profile-sample-accurate"))) && "ProfAccForSymsInList should be false when profile-sample-accurate " "is enabled") ? static_cast<void> (0) : __assert_fail ( "(!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute(\"profile-sample-accurate\"))) && \"ProfAccForSymsInList should be false when profile-sample-accurate \" \"is enabled\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 910, __PRETTY_FUNCTION__)) | |||
909 | "ProfAccForSymsInList should be false when profile-sample-accurate "(((!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute("profile-sample-accurate"))) && "ProfAccForSymsInList should be false when profile-sample-accurate " "is enabled") ? static_cast<void> (0) : __assert_fail ( "(!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute(\"profile-sample-accurate\"))) && \"ProfAccForSymsInList should be false when profile-sample-accurate \" \"is enabled\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 910, __PRETTY_FUNCTION__)) | |||
910 | "is enabled")(((!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute("profile-sample-accurate"))) && "ProfAccForSymsInList should be false when profile-sample-accurate " "is enabled") ? static_cast<void> (0) : __assert_fail ( "(!ProfAccForSymsInList || (!ProfileSampleAccurate && !F.hasFnAttribute(\"profile-sample-accurate\"))) && \"ProfAccForSymsInList should be false when profile-sample-accurate \" \"is enabled\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 910, __PRETTY_FUNCTION__)); | |||
911 | ||||
912 | DenseMap<Instruction *, const FunctionSamples *> localNotInlinedCallSites; | |||
913 | bool Changed = false; | |||
914 | while (true) { | |||
915 | bool LocalChanged = false; | |||
916 | SmallVector<Instruction *, 10> CIS; | |||
917 | for (auto &BB : F) { | |||
918 | bool Hot = false; | |||
919 | SmallVector<Instruction *, 10> Candidates; | |||
920 | for (auto &I : BB.getInstList()) { | |||
921 | const FunctionSamples *FS = nullptr; | |||
922 | if ((isa<CallInst>(I) || isa<InvokeInst>(I)) && | |||
923 | !isa<IntrinsicInst>(I) && (FS = findCalleeFunctionSamples(I))) { | |||
924 | Candidates.push_back(&I); | |||
925 | if (FS->getEntrySamples() > 0) | |||
926 | localNotInlinedCallSites.try_emplace(&I, FS); | |||
927 | if (callsiteIsHot(FS, PSI)) | |||
928 | Hot = true; | |||
929 | } | |||
930 | } | |||
931 | if (Hot) { | |||
932 | CIS.insert(CIS.begin(), Candidates.begin(), Candidates.end()); | |||
933 | } | |||
934 | } | |||
935 | for (auto I : CIS) { | |||
936 | Function *CalledFunction = CallSite(I).getCalledFunction(); | |||
937 | // Do not inline recursive calls. | |||
938 | if (CalledFunction == &F) | |||
939 | continue; | |||
940 | if (CallSite(I).isIndirectCall()) { | |||
941 | if (PromotedInsns.count(I)) | |||
942 | continue; | |||
943 | uint64_t Sum; | |||
944 | for (const auto *FS : findIndirectCallFunctionSamples(*I, Sum)) { | |||
945 | if (IsThinLTOPreLink) { | |||
946 | FS->findInlinedFunctions(InlinedGUIDs, F.getParent(), | |||
947 | PSI->getOrCompHotCountThreshold()); | |||
948 | continue; | |||
949 | } | |||
950 | auto CalleeFunctionName = FS->getFuncNameInModule(F.getParent()); | |||
951 | // If it is a recursive call, we do not inline it as it could bloat | |||
952 | // the code exponentially. There is way to better handle this, e.g. | |||
953 | // clone the caller first, and inline the cloned caller if it is | |||
954 | // recursive. As llvm does not inline recursive calls, we will | |||
955 | // simply ignore it instead of handling it explicitly. | |||
956 | if (CalleeFunctionName == F.getName()) | |||
957 | continue; | |||
958 | ||||
959 | if (!callsiteIsHot(FS, PSI)) | |||
960 | continue; | |||
961 | ||||
962 | const char *Reason = "Callee function not available"; | |||
963 | auto R = SymbolMap.find(CalleeFunctionName); | |||
964 | if (R != SymbolMap.end() && R->getValue() && | |||
965 | !R->getValue()->isDeclaration() && | |||
966 | R->getValue()->getSubprogram() && | |||
967 | isLegalToPromote(CallSite(I), R->getValue(), &Reason)) { | |||
968 | uint64_t C = FS->getEntrySamples(); | |||
969 | Instruction *DI = | |||
970 | pgo::promoteIndirectCall(I, R->getValue(), C, Sum, false, ORE); | |||
971 | Sum -= C; | |||
972 | PromotedInsns.insert(I); | |||
973 | // If profile mismatches, we should not attempt to inline DI. | |||
974 | if ((isa<CallInst>(DI) || isa<InvokeInst>(DI)) && | |||
975 | inlineCallInstruction(DI)) { | |||
976 | localNotInlinedCallSites.erase(I); | |||
977 | LocalChanged = true; | |||
978 | } | |||
979 | } else { | |||
980 | LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nFailed to promote indirect call to " << CalleeFunctionName << " because " << Reason << "\n"; } } while (false) | |||
981 | << "\nFailed to promote indirect call to "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nFailed to promote indirect call to " << CalleeFunctionName << " because " << Reason << "\n"; } } while (false) | |||
982 | << CalleeFunctionName << " because " << Reason << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nFailed to promote indirect call to " << CalleeFunctionName << " because " << Reason << "\n"; } } while (false); | |||
983 | } | |||
984 | } | |||
985 | } else if (CalledFunction && CalledFunction->getSubprogram() && | |||
986 | !CalledFunction->isDeclaration()) { | |||
987 | if (inlineCallInstruction(I)) { | |||
988 | localNotInlinedCallSites.erase(I); | |||
989 | LocalChanged = true; | |||
990 | } | |||
991 | } else if (IsThinLTOPreLink) { | |||
992 | findCalleeFunctionSamples(*I)->findInlinedFunctions( | |||
993 | InlinedGUIDs, F.getParent(), PSI->getOrCompHotCountThreshold()); | |||
994 | } | |||
995 | } | |||
996 | if (LocalChanged) { | |||
997 | Changed = true; | |||
998 | } else { | |||
999 | break; | |||
1000 | } | |||
1001 | } | |||
1002 | ||||
1003 | // Accumulate not inlined callsite information into notInlinedSamples | |||
1004 | for (const auto &Pair : localNotInlinedCallSites) { | |||
1005 | Instruction *I = Pair.getFirst(); | |||
1006 | Function *Callee = CallSite(I).getCalledFunction(); | |||
1007 | if (!Callee || Callee->isDeclaration()) | |||
1008 | continue; | |||
1009 | const FunctionSamples *FS = Pair.getSecond(); | |||
1010 | auto pair = | |||
1011 | notInlinedCallInfo.try_emplace(Callee, NotInlinedProfileInfo{0}); | |||
1012 | pair.first->second.entryCount += FS->getEntrySamples(); | |||
1013 | } | |||
1014 | return Changed; | |||
1015 | } | |||
1016 | ||||
1017 | /// Find equivalence classes for the given block. | |||
1018 | /// | |||
1019 | /// This finds all the blocks that are guaranteed to execute the same | |||
1020 | /// number of times as \p BB1. To do this, it traverses all the | |||
1021 | /// descendants of \p BB1 in the dominator or post-dominator tree. | |||
1022 | /// | |||
1023 | /// A block BB2 will be in the same equivalence class as \p BB1 if | |||
1024 | /// the following holds: | |||
1025 | /// | |||
1026 | /// 1- \p BB1 is a descendant of BB2 in the opposite tree. So, if BB2 | |||
1027 | /// is a descendant of \p BB1 in the dominator tree, then BB2 should | |||
1028 | /// dominate BB1 in the post-dominator tree. | |||
1029 | /// | |||
1030 | /// 2- Both BB2 and \p BB1 must be in the same loop. | |||
1031 | /// | |||
1032 | /// For every block BB2 that meets those two requirements, we set BB2's | |||
1033 | /// equivalence class to \p BB1. | |||
1034 | /// | |||
1035 | /// \param BB1 Block to check. | |||
1036 | /// \param Descendants Descendants of \p BB1 in either the dom or pdom tree. | |||
1037 | /// \param DomTree Opposite dominator tree. If \p Descendants is filled | |||
1038 | /// with blocks from \p BB1's dominator tree, then | |||
1039 | /// this is the post-dominator tree, and vice versa. | |||
1040 | template <bool IsPostDom> | |||
1041 | void SampleProfileLoader::findEquivalencesFor( | |||
1042 | BasicBlock *BB1, ArrayRef<BasicBlock *> Descendants, | |||
1043 | DominatorTreeBase<BasicBlock, IsPostDom> *DomTree) { | |||
1044 | const BasicBlock *EC = EquivalenceClass[BB1]; | |||
1045 | uint64_t Weight = BlockWeights[EC]; | |||
1046 | for (const auto *BB2 : Descendants) { | |||
1047 | bool IsDomParent = DomTree->dominates(BB2, BB1); | |||
1048 | bool IsInSameLoop = LI->getLoopFor(BB1) == LI->getLoopFor(BB2); | |||
1049 | if (BB1 != BB2 && IsDomParent && IsInSameLoop) { | |||
1050 | EquivalenceClass[BB2] = EC; | |||
1051 | // If BB2 is visited, then the entire EC should be marked as visited. | |||
1052 | if (VisitedBlocks.count(BB2)) { | |||
1053 | VisitedBlocks.insert(EC); | |||
1054 | } | |||
1055 | ||||
1056 | // If BB2 is heavier than BB1, make BB2 have the same weight | |||
1057 | // as BB1. | |||
1058 | // | |||
1059 | // Note that we don't worry about the opposite situation here | |||
1060 | // (when BB2 is lighter than BB1). We will deal with this | |||
1061 | // during the propagation phase. Right now, we just want to | |||
1062 | // make sure that BB1 has the largest weight of all the | |||
1063 | // members of its equivalence set. | |||
1064 | Weight = std::max(Weight, BlockWeights[BB2]); | |||
1065 | } | |||
1066 | } | |||
1067 | if (EC == &EC->getParent()->getEntryBlock()) { | |||
1068 | BlockWeights[EC] = Samples->getHeadSamples() + 1; | |||
1069 | } else { | |||
1070 | BlockWeights[EC] = Weight; | |||
1071 | } | |||
1072 | } | |||
1073 | ||||
1074 | /// Find equivalence classes. | |||
1075 | /// | |||
1076 | /// Since samples may be missing from blocks, we can fill in the gaps by setting | |||
1077 | /// the weights of all the blocks in the same equivalence class to the same | |||
1078 | /// weight. To compute the concept of equivalence, we use dominance and loop | |||
1079 | /// information. Two blocks B1 and B2 are in the same equivalence class if B1 | |||
1080 | /// dominates B2, B2 post-dominates B1 and both are in the same loop. | |||
1081 | /// | |||
1082 | /// \param F The function to query. | |||
1083 | void SampleProfileLoader::findEquivalenceClasses(Function &F) { | |||
1084 | SmallVector<BasicBlock *, 8> DominatedBBs; | |||
1085 | LLVM_DEBUG(dbgs() << "\nBlock equivalence classes\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nBlock equivalence classes\n" ; } } while (false); | |||
1086 | // Find equivalence sets based on dominance and post-dominance information. | |||
1087 | for (auto &BB : F) { | |||
1088 | BasicBlock *BB1 = &BB; | |||
1089 | ||||
1090 | // Compute BB1's equivalence class once. | |||
1091 | if (EquivalenceClass.count(BB1)) { | |||
1092 | LLVM_DEBUG(printBlockEquivalence(dbgs(), BB1))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { printBlockEquivalence(dbgs(), BB1); } } while (false); | |||
1093 | continue; | |||
1094 | } | |||
1095 | ||||
1096 | // By default, blocks are in their own equivalence class. | |||
1097 | EquivalenceClass[BB1] = BB1; | |||
1098 | ||||
1099 | // Traverse all the blocks dominated by BB1. We are looking for | |||
1100 | // every basic block BB2 such that: | |||
1101 | // | |||
1102 | // 1- BB1 dominates BB2. | |||
1103 | // 2- BB2 post-dominates BB1. | |||
1104 | // 3- BB1 and BB2 are in the same loop nest. | |||
1105 | // | |||
1106 | // If all those conditions hold, it means that BB2 is executed | |||
1107 | // as many times as BB1, so they are placed in the same equivalence | |||
1108 | // class by making BB2's equivalence class be BB1. | |||
1109 | DominatedBBs.clear(); | |||
1110 | DT->getDescendants(BB1, DominatedBBs); | |||
1111 | findEquivalencesFor(BB1, DominatedBBs, PDT.get()); | |||
1112 | ||||
1113 | LLVM_DEBUG(printBlockEquivalence(dbgs(), BB1))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { printBlockEquivalence(dbgs(), BB1); } } while (false); | |||
1114 | } | |||
1115 | ||||
1116 | // Assign weights to equivalence classes. | |||
1117 | // | |||
1118 | // All the basic blocks in the same equivalence class will execute | |||
1119 | // the same number of times. Since we know that the head block in | |||
1120 | // each equivalence class has the largest weight, assign that weight | |||
1121 | // to all the blocks in that equivalence class. | |||
1122 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nAssign the same weight to all blocks in the same class\n" ; } } while (false) | |||
1123 | dbgs() << "\nAssign the same weight to all blocks in the same class\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nAssign the same weight to all blocks in the same class\n" ; } } while (false); | |||
1124 | for (auto &BI : F) { | |||
1125 | const BasicBlock *BB = &BI; | |||
1126 | const BasicBlock *EquivBB = EquivalenceClass[BB]; | |||
1127 | if (BB != EquivBB) | |||
1128 | BlockWeights[BB] = BlockWeights[EquivBB]; | |||
1129 | LLVM_DEBUG(printBlockWeight(dbgs(), BB))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { printBlockWeight(dbgs(), BB); } } while (false); | |||
1130 | } | |||
1131 | } | |||
1132 | ||||
1133 | /// Visit the given edge to decide if it has a valid weight. | |||
1134 | /// | |||
1135 | /// If \p E has not been visited before, we copy to \p UnknownEdge | |||
1136 | /// and increment the count of unknown edges. | |||
1137 | /// | |||
1138 | /// \param E Edge to visit. | |||
1139 | /// \param NumUnknownEdges Current number of unknown edges. | |||
1140 | /// \param UnknownEdge Set if E has not been visited before. | |||
1141 | /// | |||
1142 | /// \returns E's weight, if known. Otherwise, return 0. | |||
1143 | uint64_t SampleProfileLoader::visitEdge(Edge E, unsigned *NumUnknownEdges, | |||
1144 | Edge *UnknownEdge) { | |||
1145 | if (!VisitedEdges.count(E)) { | |||
1146 | (*NumUnknownEdges)++; | |||
1147 | *UnknownEdge = E; | |||
1148 | return 0; | |||
1149 | } | |||
1150 | ||||
1151 | return EdgeWeights[E]; | |||
1152 | } | |||
1153 | ||||
1154 | /// Propagate weights through incoming/outgoing edges. | |||
1155 | /// | |||
1156 | /// If the weight of a basic block is known, and there is only one edge | |||
1157 | /// with an unknown weight, we can calculate the weight of that edge. | |||
1158 | /// | |||
1159 | /// Similarly, if all the edges have a known count, we can calculate the | |||
1160 | /// count of the basic block, if needed. | |||
1161 | /// | |||
1162 | /// \param F Function to process. | |||
1163 | /// \param UpdateBlockCount Whether we should update basic block counts that | |||
1164 | /// has already been annotated. | |||
1165 | /// | |||
1166 | /// \returns True if new weights were assigned to edges or blocks. | |||
1167 | bool SampleProfileLoader::propagateThroughEdges(Function &F, | |||
1168 | bool UpdateBlockCount) { | |||
1169 | bool Changed = false; | |||
1170 | LLVM_DEBUG(dbgs() << "\nPropagation through edges\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nPropagation through edges\n" ; } } while (false); | |||
1171 | for (const auto &BI : F) { | |||
1172 | const BasicBlock *BB = &BI; | |||
1173 | const BasicBlock *EC = EquivalenceClass[BB]; | |||
1174 | ||||
1175 | // Visit all the predecessor and successor edges to determine | |||
1176 | // which ones have a weight assigned already. Note that it doesn't | |||
1177 | // matter that we only keep track of a single unknown edge. The | |||
1178 | // only case we are interested in handling is when only a single | |||
1179 | // edge is unknown (see setEdgeOrBlockWeight). | |||
1180 | for (unsigned i = 0; i < 2; i++) { | |||
1181 | uint64_t TotalWeight = 0; | |||
1182 | unsigned NumUnknownEdges = 0, NumTotalEdges = 0; | |||
1183 | Edge UnknownEdge, SelfReferentialEdge, SingleEdge; | |||
1184 | ||||
1185 | if (i == 0) { | |||
1186 | // First, visit all predecessor edges. | |||
1187 | NumTotalEdges = Predecessors[BB].size(); | |||
1188 | for (auto *Pred : Predecessors[BB]) { | |||
1189 | Edge E = std::make_pair(Pred, BB); | |||
1190 | TotalWeight += visitEdge(E, &NumUnknownEdges, &UnknownEdge); | |||
1191 | if (E.first == E.second) | |||
1192 | SelfReferentialEdge = E; | |||
1193 | } | |||
1194 | if (NumTotalEdges == 1) { | |||
1195 | SingleEdge = std::make_pair(Predecessors[BB][0], BB); | |||
1196 | } | |||
1197 | } else { | |||
1198 | // On the second round, visit all successor edges. | |||
1199 | NumTotalEdges = Successors[BB].size(); | |||
1200 | for (auto *Succ : Successors[BB]) { | |||
1201 | Edge E = std::make_pair(BB, Succ); | |||
1202 | TotalWeight += visitEdge(E, &NumUnknownEdges, &UnknownEdge); | |||
1203 | } | |||
1204 | if (NumTotalEdges == 1) { | |||
1205 | SingleEdge = std::make_pair(BB, Successors[BB][0]); | |||
1206 | } | |||
1207 | } | |||
1208 | ||||
1209 | // After visiting all the edges, there are three cases that we | |||
1210 | // can handle immediately: | |||
1211 | // | |||
1212 | // - All the edge weights are known (i.e., NumUnknownEdges == 0). | |||
1213 | // In this case, we simply check that the sum of all the edges | |||
1214 | // is the same as BB's weight. If not, we change BB's weight | |||
1215 | // to match. Additionally, if BB had not been visited before, | |||
1216 | // we mark it visited. | |||
1217 | // | |||
1218 | // - Only one edge is unknown and BB has already been visited. | |||
1219 | // In this case, we can compute the weight of the edge by | |||
1220 | // subtracting the total block weight from all the known | |||
1221 | // edge weights. If the edges weight more than BB, then the | |||
1222 | // edge of the last remaining edge is set to zero. | |||
1223 | // | |||
1224 | // - There exists a self-referential edge and the weight of BB is | |||
1225 | // known. In this case, this edge can be based on BB's weight. | |||
1226 | // We add up all the other known edges and set the weight on | |||
1227 | // the self-referential edge as we did in the previous case. | |||
1228 | // | |||
1229 | // In any other case, we must continue iterating. Eventually, | |||
1230 | // all edges will get a weight, or iteration will stop when | |||
1231 | // it reaches SampleProfileMaxPropagateIterations. | |||
1232 | if (NumUnknownEdges <= 1) { | |||
1233 | uint64_t &BBWeight = BlockWeights[EC]; | |||
1234 | if (NumUnknownEdges == 0) { | |||
1235 | if (!VisitedBlocks.count(EC)) { | |||
1236 | // If we already know the weight of all edges, the weight of the | |||
1237 | // basic block can be computed. It should be no larger than the sum | |||
1238 | // of all edge weights. | |||
1239 | if (TotalWeight > BBWeight) { | |||
1240 | BBWeight = TotalWeight; | |||
1241 | Changed = true; | |||
1242 | LLVM_DEBUG(dbgs() << "All edge weights for " << BB->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "All edge weights for " << BB->getName() << " known. Set weight for block: " ; printBlockWeight(dbgs(), BB);; } } while (false) | |||
1243 | << " known. Set weight for block: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "All edge weights for " << BB->getName() << " known. Set weight for block: " ; printBlockWeight(dbgs(), BB);; } } while (false) | |||
1244 | printBlockWeight(dbgs(), BB);)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "All edge weights for " << BB->getName() << " known. Set weight for block: " ; printBlockWeight(dbgs(), BB);; } } while (false); | |||
1245 | } | |||
1246 | } else if (NumTotalEdges == 1 && | |||
1247 | EdgeWeights[SingleEdge] < BlockWeights[EC]) { | |||
1248 | // If there is only one edge for the visited basic block, use the | |||
1249 | // block weight to adjust edge weight if edge weight is smaller. | |||
1250 | EdgeWeights[SingleEdge] = BlockWeights[EC]; | |||
1251 | Changed = true; | |||
1252 | } | |||
1253 | } else if (NumUnknownEdges == 1 && VisitedBlocks.count(EC)) { | |||
1254 | // If there is a single unknown edge and the block has been | |||
1255 | // visited, then we can compute E's weight. | |||
1256 | if (BBWeight >= TotalWeight) | |||
1257 | EdgeWeights[UnknownEdge] = BBWeight - TotalWeight; | |||
1258 | else | |||
1259 | EdgeWeights[UnknownEdge] = 0; | |||
1260 | const BasicBlock *OtherEC; | |||
1261 | if (i == 0) | |||
1262 | OtherEC = EquivalenceClass[UnknownEdge.first]; | |||
1263 | else | |||
1264 | OtherEC = EquivalenceClass[UnknownEdge.second]; | |||
1265 | // Edge weights should never exceed the BB weights it connects. | |||
1266 | if (VisitedBlocks.count(OtherEC) && | |||
1267 | EdgeWeights[UnknownEdge] > BlockWeights[OtherEC]) | |||
1268 | EdgeWeights[UnknownEdge] = BlockWeights[OtherEC]; | |||
1269 | VisitedEdges.insert(UnknownEdge); | |||
1270 | Changed = true; | |||
1271 | LLVM_DEBUG(dbgs() << "Set weight for edge: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Set weight for edge: " ; printEdgeWeight(dbgs(), UnknownEdge); } } while (false) | |||
1272 | printEdgeWeight(dbgs(), UnknownEdge))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Set weight for edge: " ; printEdgeWeight(dbgs(), UnknownEdge); } } while (false); | |||
1273 | } | |||
1274 | } else if (VisitedBlocks.count(EC) && BlockWeights[EC] == 0) { | |||
1275 | // If a block Weights 0, all its in/out edges should weight 0. | |||
1276 | if (i == 0) { | |||
1277 | for (auto *Pred : Predecessors[BB]) { | |||
1278 | Edge E = std::make_pair(Pred, BB); | |||
1279 | EdgeWeights[E] = 0; | |||
1280 | VisitedEdges.insert(E); | |||
1281 | } | |||
1282 | } else { | |||
1283 | for (auto *Succ : Successors[BB]) { | |||
1284 | Edge E = std::make_pair(BB, Succ); | |||
1285 | EdgeWeights[E] = 0; | |||
1286 | VisitedEdges.insert(E); | |||
1287 | } | |||
1288 | } | |||
1289 | } else if (SelfReferentialEdge.first && VisitedBlocks.count(EC)) { | |||
1290 | uint64_t &BBWeight = BlockWeights[BB]; | |||
1291 | // We have a self-referential edge and the weight of BB is known. | |||
1292 | if (BBWeight >= TotalWeight) | |||
1293 | EdgeWeights[SelfReferentialEdge] = BBWeight - TotalWeight; | |||
1294 | else | |||
1295 | EdgeWeights[SelfReferentialEdge] = 0; | |||
1296 | VisitedEdges.insert(SelfReferentialEdge); | |||
1297 | Changed = true; | |||
1298 | LLVM_DEBUG(dbgs() << "Set self-referential edge weight to: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Set self-referential edge weight to: " ; printEdgeWeight(dbgs(), SelfReferentialEdge); } } while (false ) | |||
1299 | printEdgeWeight(dbgs(), SelfReferentialEdge))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Set self-referential edge weight to: " ; printEdgeWeight(dbgs(), SelfReferentialEdge); } } while (false ); | |||
1300 | } | |||
1301 | if (UpdateBlockCount && !VisitedBlocks.count(EC) && TotalWeight > 0) { | |||
1302 | BlockWeights[EC] = TotalWeight; | |||
1303 | VisitedBlocks.insert(EC); | |||
1304 | Changed = true; | |||
1305 | } | |||
1306 | } | |||
1307 | } | |||
1308 | ||||
1309 | return Changed; | |||
1310 | } | |||
1311 | ||||
1312 | /// Build in/out edge lists for each basic block in the CFG. | |||
1313 | /// | |||
1314 | /// We are interested in unique edges. If a block B1 has multiple | |||
1315 | /// edges to another block B2, we only add a single B1->B2 edge. | |||
1316 | void SampleProfileLoader::buildEdges(Function &F) { | |||
1317 | for (auto &BI : F) { | |||
1318 | BasicBlock *B1 = &BI; | |||
1319 | ||||
1320 | // Add predecessors for B1. | |||
1321 | SmallPtrSet<BasicBlock *, 16> Visited; | |||
1322 | if (!Predecessors[B1].empty()) | |||
1323 | llvm_unreachable("Found a stale predecessors list in a basic block.")::llvm::llvm_unreachable_internal("Found a stale predecessors list in a basic block." , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 1323); | |||
1324 | for (pred_iterator PI = pred_begin(B1), PE = pred_end(B1); PI != PE; ++PI) { | |||
1325 | BasicBlock *B2 = *PI; | |||
1326 | if (Visited.insert(B2).second) | |||
1327 | Predecessors[B1].push_back(B2); | |||
1328 | } | |||
1329 | ||||
1330 | // Add successors for B1. | |||
1331 | Visited.clear(); | |||
1332 | if (!Successors[B1].empty()) | |||
1333 | llvm_unreachable("Found a stale successors list in a basic block.")::llvm::llvm_unreachable_internal("Found a stale successors list in a basic block." , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/IPO/SampleProfile.cpp" , 1333); | |||
1334 | for (succ_iterator SI = succ_begin(B1), SE = succ_end(B1); SI != SE; ++SI) { | |||
1335 | BasicBlock *B2 = *SI; | |||
1336 | if (Visited.insert(B2).second) | |||
1337 | Successors[B1].push_back(B2); | |||
1338 | } | |||
1339 | } | |||
1340 | } | |||
1341 | ||||
1342 | /// Returns the sorted CallTargetMap \p M by count in descending order. | |||
1343 | static SmallVector<InstrProfValueData, 2> GetSortedValueDataFromCallTargets( | |||
1344 | const SampleRecord::CallTargetMap & M) { | |||
1345 | SmallVector<InstrProfValueData, 2> R; | |||
1346 | for (const auto &I : SampleRecord::SortCallTargets(M)) { | |||
1347 | R.emplace_back(InstrProfValueData{FunctionSamples::getGUID(I.first), I.second}); | |||
1348 | } | |||
1349 | return R; | |||
1350 | } | |||
1351 | ||||
1352 | /// Propagate weights into edges | |||
1353 | /// | |||
1354 | /// The following rules are applied to every block BB in the CFG: | |||
1355 | /// | |||
1356 | /// - If BB has a single predecessor/successor, then the weight | |||
1357 | /// of that edge is the weight of the block. | |||
1358 | /// | |||
1359 | /// - If all incoming or outgoing edges are known except one, and the | |||
1360 | /// weight of the block is already known, the weight of the unknown | |||
1361 | /// edge will be the weight of the block minus the sum of all the known | |||
1362 | /// edges. If the sum of all the known edges is larger than BB's weight, | |||
1363 | /// we set the unknown edge weight to zero. | |||
1364 | /// | |||
1365 | /// - If there is a self-referential edge, and the weight of the block is | |||
1366 | /// known, the weight for that edge is set to the weight of the block | |||
1367 | /// minus the weight of the other incoming edges to that block (if | |||
1368 | /// known). | |||
1369 | void SampleProfileLoader::propagateWeights(Function &F) { | |||
1370 | bool Changed = true; | |||
1371 | unsigned I = 0; | |||
1372 | ||||
1373 | // If BB weight is larger than its corresponding loop's header BB weight, | |||
1374 | // use the BB weight to replace the loop header BB weight. | |||
1375 | for (auto &BI : F) { | |||
1376 | BasicBlock *BB = &BI; | |||
1377 | Loop *L = LI->getLoopFor(BB); | |||
1378 | if (!L) { | |||
1379 | continue; | |||
1380 | } | |||
1381 | BasicBlock *Header = L->getHeader(); | |||
1382 | if (Header && BlockWeights[BB] > BlockWeights[Header]) { | |||
1383 | BlockWeights[Header] = BlockWeights[BB]; | |||
1384 | } | |||
1385 | } | |||
1386 | ||||
1387 | // Before propagation starts, build, for each block, a list of | |||
1388 | // unique predecessors and successors. This is necessary to handle | |||
1389 | // identical edges in multiway branches. Since we visit all blocks and all | |||
1390 | // edges of the CFG, it is cleaner to build these lists once at the start | |||
1391 | // of the pass. | |||
1392 | buildEdges(F); | |||
1393 | ||||
1394 | // Propagate until we converge or we go past the iteration limit. | |||
1395 | while (Changed && I++ < SampleProfileMaxPropagateIterations) { | |||
1396 | Changed = propagateThroughEdges(F, false); | |||
1397 | } | |||
1398 | ||||
1399 | // The first propagation propagates BB counts from annotated BBs to unknown | |||
1400 | // BBs. The 2nd propagation pass resets edges weights, and use all BB weights | |||
1401 | // to propagate edge weights. | |||
1402 | VisitedEdges.clear(); | |||
1403 | Changed = true; | |||
1404 | while (Changed && I++ < SampleProfileMaxPropagateIterations) { | |||
1405 | Changed = propagateThroughEdges(F, false); | |||
1406 | } | |||
1407 | ||||
1408 | // The 3rd propagation pass allows adjust annotated BB weights that are | |||
1409 | // obviously wrong. | |||
1410 | Changed = true; | |||
1411 | while (Changed && I++ < SampleProfileMaxPropagateIterations) { | |||
1412 | Changed = propagateThroughEdges(F, true); | |||
1413 | } | |||
1414 | ||||
1415 | // Generate MD_prof metadata for every branch instruction using the | |||
1416 | // edge weights computed during propagation. | |||
1417 | LLVM_DEBUG(dbgs() << "\nPropagation complete. Setting branch weights\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nPropagation complete. Setting branch weights\n" ; } } while (false); | |||
1418 | LLVMContext &Ctx = F.getContext(); | |||
1419 | MDBuilder MDB(Ctx); | |||
1420 | for (auto &BI : F) { | |||
1421 | BasicBlock *BB = &BI; | |||
1422 | ||||
1423 | if (BlockWeights[BB]) { | |||
1424 | for (auto &I : BB->getInstList()) { | |||
1425 | if (!isa<CallInst>(I) && !isa<InvokeInst>(I)) | |||
1426 | continue; | |||
1427 | CallSite CS(&I); | |||
1428 | if (!CS.getCalledFunction()) { | |||
1429 | const DebugLoc &DLoc = I.getDebugLoc(); | |||
1430 | if (!DLoc) | |||
1431 | continue; | |||
1432 | const DILocation *DIL = DLoc; | |||
1433 | uint32_t LineOffset = FunctionSamples::getOffset(DIL); | |||
1434 | uint32_t Discriminator = DIL->getBaseDiscriminator(); | |||
1435 | ||||
1436 | const FunctionSamples *FS = findFunctionSamples(I); | |||
1437 | if (!FS) | |||
1438 | continue; | |||
1439 | auto T = FS->findCallTargetMapAt(LineOffset, Discriminator); | |||
1440 | if (!T || T.get().empty()) | |||
1441 | continue; | |||
1442 | SmallVector<InstrProfValueData, 2> SortedCallTargets = | |||
1443 | GetSortedValueDataFromCallTargets(T.get()); | |||
1444 | uint64_t Sum; | |||
1445 | findIndirectCallFunctionSamples(I, Sum); | |||
1446 | annotateValueSite(*I.getParent()->getParent()->getParent(), I, | |||
1447 | SortedCallTargets, Sum, IPVK_IndirectCallTarget, | |||
1448 | SortedCallTargets.size()); | |||
1449 | } else if (!isa<IntrinsicInst>(&I)) { | |||
1450 | I.setMetadata(LLVMContext::MD_prof, | |||
1451 | MDB.createBranchWeights( | |||
1452 | {static_cast<uint32_t>(BlockWeights[BB])})); | |||
1453 | } | |||
1454 | } | |||
1455 | } | |||
1456 | Instruction *TI = BB->getTerminator(); | |||
1457 | if (TI->getNumSuccessors() == 1) | |||
1458 | continue; | |||
1459 | if (!isa<BranchInst>(TI) && !isa<SwitchInst>(TI)) | |||
1460 | continue; | |||
1461 | ||||
1462 | DebugLoc BranchLoc = TI->getDebugLoc(); | |||
1463 | LLVM_DEBUG(dbgs() << "\nGetting weights for branch at line "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nGetting weights for branch at line " << ((BranchLoc) ? Twine(BranchLoc.getLine()) : Twine("<UNKNOWN LOCATION>" )) << ".\n"; } } while (false) | |||
1464 | << ((BranchLoc) ? Twine(BranchLoc.getLine())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nGetting weights for branch at line " << ((BranchLoc) ? Twine(BranchLoc.getLine()) : Twine("<UNKNOWN LOCATION>" )) << ".\n"; } } while (false) | |||
1465 | : Twine("<UNKNOWN LOCATION>"))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nGetting weights for branch at line " << ((BranchLoc) ? Twine(BranchLoc.getLine()) : Twine("<UNKNOWN LOCATION>" )) << ".\n"; } } while (false) | |||
1466 | << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\nGetting weights for branch at line " << ((BranchLoc) ? Twine(BranchLoc.getLine()) : Twine("<UNKNOWN LOCATION>" )) << ".\n"; } } while (false); | |||
1467 | SmallVector<uint32_t, 4> Weights; | |||
1468 | uint32_t MaxWeight = 0; | |||
1469 | Instruction *MaxDestInst; | |||
1470 | for (unsigned I = 0; I < TI->getNumSuccessors(); ++I) { | |||
1471 | BasicBlock *Succ = TI->getSuccessor(I); | |||
1472 | Edge E = std::make_pair(BB, Succ); | |||
1473 | uint64_t Weight = EdgeWeights[E]; | |||
1474 | LLVM_DEBUG(dbgs() << "\t"; printEdgeWeight(dbgs(), E))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "\t"; printEdgeWeight(dbgs (), E); } } while (false); | |||
1475 | // Use uint32_t saturated arithmetic to adjust the incoming weights, | |||
1476 | // if needed. Sample counts in profiles are 64-bit unsigned values, | |||
1477 | // but internally branch weights are expressed as 32-bit values. | |||
1478 | if (Weight > std::numeric_limits<uint32_t>::max()) { | |||
1479 | LLVM_DEBUG(dbgs() << " (saturated due to uint32_t overflow)")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << " (saturated due to uint32_t overflow)" ; } } while (false); | |||
1480 | Weight = std::numeric_limits<uint32_t>::max(); | |||
1481 | } | |||
1482 | // Weight is added by one to avoid propagation errors introduced by | |||
1483 | // 0 weights. | |||
1484 | Weights.push_back(static_cast<uint32_t>(Weight + 1)); | |||
1485 | if (Weight != 0) { | |||
1486 | if (Weight > MaxWeight) { | |||
1487 | MaxWeight = Weight; | |||
1488 | MaxDestInst = Succ->getFirstNonPHIOrDbgOrLifetime(); | |||
1489 | } | |||
1490 | } | |||
1491 | } | |||
1492 | ||||
1493 | misexpect::verifyMisExpect(TI, Weights, TI->getContext()); | |||
1494 | ||||
1495 | uint64_t TempWeight; | |||
1496 | // Only set weights if there is at least one non-zero weight. | |||
1497 | // In any other case, let the analyzer set weights. | |||
1498 | // Do not set weights if the weights are present. In ThinLTO, the profile | |||
1499 | // annotation is done twice. If the first annotation already set the | |||
1500 | // weights, the second pass does not need to set it. | |||
1501 | if (MaxWeight > 0 && !TI->extractProfTotalWeight(TempWeight)) { | |||
1502 | LLVM_DEBUG(dbgs() << "SUCCESS. Found non-zero weights.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "SUCCESS. Found non-zero weights.\n" ; } } while (false); | |||
1503 | TI->setMetadata(LLVMContext::MD_prof, | |||
1504 | MDB.createBranchWeights(Weights)); | |||
1505 | ORE->emit([&]() { | |||
1506 | return OptimizationRemark(DEBUG_TYPE"sample-profile", "PopularDest", MaxDestInst) | |||
1507 | << "most popular destination for conditional branches at " | |||
1508 | << ore::NV("CondBranchesLoc", BranchLoc); | |||
1509 | }); | |||
1510 | } else { | |||
1511 | LLVM_DEBUG(dbgs() << "SKIPPED. All branch weights are zero.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "SKIPPED. All branch weights are zero.\n" ; } } while (false); | |||
1512 | } | |||
1513 | } | |||
1514 | } | |||
1515 | ||||
1516 | /// Get the line number for the function header. | |||
1517 | /// | |||
1518 | /// This looks up function \p F in the current compilation unit and | |||
1519 | /// retrieves the line number where the function is defined. This is | |||
1520 | /// line 0 for all the samples read from the profile file. Every line | |||
1521 | /// number is relative to this line. | |||
1522 | /// | |||
1523 | /// \param F Function object to query. | |||
1524 | /// | |||
1525 | /// \returns the line number where \p F is defined. If it returns 0, | |||
1526 | /// it means that there is no debug information available for \p F. | |||
1527 | unsigned SampleProfileLoader::getFunctionLoc(Function &F) { | |||
1528 | if (DISubprogram *S = F.getSubprogram()) | |||
1529 | return S->getLine(); | |||
1530 | ||||
1531 | if (NoWarnSampleUnused) | |||
1532 | return 0; | |||
1533 | ||||
1534 | // If the start of \p F is missing, emit a diagnostic to inform the user | |||
1535 | // about the missed opportunity. | |||
1536 | F.getContext().diagnose(DiagnosticInfoSampleProfile( | |||
1537 | "No debug information found in function " + F.getName() + | |||
1538 | ": Function profile not used", | |||
1539 | DS_Warning)); | |||
1540 | return 0; | |||
1541 | } | |||
1542 | ||||
1543 | void SampleProfileLoader::computeDominanceAndLoopInfo(Function &F) { | |||
1544 | DT.reset(new DominatorTree); | |||
1545 | DT->recalculate(F); | |||
1546 | ||||
1547 | PDT.reset(new PostDominatorTree(F)); | |||
1548 | ||||
1549 | LI.reset(new LoopInfo); | |||
1550 | LI->analyze(*DT); | |||
1551 | } | |||
1552 | ||||
1553 | /// Generate branch weight metadata for all branches in \p F. | |||
1554 | /// | |||
1555 | /// Branch weights are computed out of instruction samples using a | |||
1556 | /// propagation heuristic. Propagation proceeds in 3 phases: | |||
1557 | /// | |||
1558 | /// 1- Assignment of block weights. All the basic blocks in the function | |||
1559 | /// are initial assigned the same weight as their most frequently | |||
1560 | /// executed instruction. | |||
1561 | /// | |||
1562 | /// 2- Creation of equivalence classes. Since samples may be missing from | |||
1563 | /// blocks, we can fill in the gaps by setting the weights of all the | |||
1564 | /// blocks in the same equivalence class to the same weight. To compute | |||
1565 | /// the concept of equivalence, we use dominance and loop information. | |||
1566 | /// Two blocks B1 and B2 are in the same equivalence class if B1 | |||
1567 | /// dominates B2, B2 post-dominates B1 and both are in the same loop. | |||
1568 | /// | |||
1569 | /// 3- Propagation of block weights into edges. This uses a simple | |||
1570 | /// propagation heuristic. The following rules are applied to every | |||
1571 | /// block BB in the CFG: | |||
1572 | /// | |||
1573 | /// - If BB has a single predecessor/successor, then the weight | |||
1574 | /// of that edge is the weight of the block. | |||
1575 | /// | |||
1576 | /// - If all the edges are known except one, and the weight of the | |||
1577 | /// block is already known, the weight of the unknown edge will | |||
1578 | /// be the weight of the block minus the sum of all the known | |||
1579 | /// edges. If the sum of all the known edges is larger than BB's weight, | |||
1580 | /// we set the unknown edge weight to zero. | |||
1581 | /// | |||
1582 | /// - If there is a self-referential edge, and the weight of the block is | |||
1583 | /// known, the weight for that edge is set to the weight of the block | |||
1584 | /// minus the weight of the other incoming edges to that block (if | |||
1585 | /// known). | |||
1586 | /// | |||
1587 | /// Since this propagation is not guaranteed to finalize for every CFG, we | |||
1588 | /// only allow it to proceed for a limited number of iterations (controlled | |||
1589 | /// by -sample-profile-max-propagate-iterations). | |||
1590 | /// | |||
1591 | /// FIXME: Try to replace this propagation heuristic with a scheme | |||
1592 | /// that is guaranteed to finalize. A work-list approach similar to | |||
1593 | /// the standard value propagation algorithm used by SSA-CCP might | |||
1594 | /// work here. | |||
1595 | /// | |||
1596 | /// Once all the branch weights are computed, we emit the MD_prof | |||
1597 | /// metadata on BB using the computed values for each of its branches. | |||
1598 | /// | |||
1599 | /// \param F The function to query. | |||
1600 | /// | |||
1601 | /// \returns true if \p F was modified. Returns false, otherwise. | |||
1602 | bool SampleProfileLoader::emitAnnotations(Function &F) { | |||
1603 | bool Changed = false; | |||
1604 | ||||
1605 | if (getFunctionLoc(F) == 0) | |||
1606 | return false; | |||
1607 | ||||
1608 | LLVM_DEBUG(dbgs() << "Line number for the first instruction in "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Line number for the first instruction in " << F.getName() << ": " << getFunctionLoc(F ) << "\n"; } } while (false) | |||
1609 | << F.getName() << ": " << getFunctionLoc(F) << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("sample-profile")) { dbgs() << "Line number for the first instruction in " << F.getName() << ": " << getFunctionLoc(F ) << "\n"; } } while (false); | |||
1610 | ||||
1611 | DenseSet<GlobalValue::GUID> InlinedGUIDs; | |||
1612 | Changed |= inlineHotFunctions(F, InlinedGUIDs); | |||
1613 | ||||
1614 | // Compute basic block weights. | |||
1615 | Changed |= computeBlockWeights(F); | |||
1616 | ||||
1617 | if (Changed) { | |||
1618 | // Add an entry count to the function using the samples gathered at the | |||
1619 | // function entry. | |||
1620 | // Sets the GUIDs that are inlined in the profiled binary. This is used | |||
1621 | // for ThinLink to make correct liveness analysis, and also make the IR | |||
1622 | // match the profiled binary before annotation. | |||
1623 | F.setEntryCount( | |||
1624 | ProfileCount(Samples->getHeadSamples() + 1, Function::PCT_Real), | |||
1625 | &InlinedGUIDs); | |||
1626 | ||||
1627 | // Compute dominance and loop info needed for propagation. | |||
1628 | computeDominanceAndLoopInfo(F); | |||
1629 | ||||
1630 | // Find equivalence classes. | |||
1631 | findEquivalenceClasses(F); | |||
1632 | ||||
1633 | // Propagate weights to all edges. | |||
1634 | propagateWeights(F); | |||
1635 | } | |||
1636 | ||||
1637 | // If coverage checking was requested, compute it now. | |||
1638 | if (SampleProfileRecordCoverage) { | |||
1639 | unsigned Used = CoverageTracker.countUsedRecords(Samples, PSI); | |||
1640 | unsigned Total = CoverageTracker.countBodyRecords(Samples, PSI); | |||
1641 | unsigned Coverage = CoverageTracker.computeCoverage(Used, Total); | |||
1642 | if (Coverage < SampleProfileRecordCoverage) { | |||
1643 | F.getContext().diagnose(DiagnosticInfoSampleProfile( | |||
1644 | F.getSubprogram()->getFilename(), getFunctionLoc(F), | |||
1645 | Twine(Used) + " of " + Twine(Total) + " available profile records (" + | |||
1646 | Twine(Coverage) + "%) were applied", | |||
1647 | DS_Warning)); | |||
1648 | } | |||
1649 | } | |||
1650 | ||||
1651 | if (SampleProfileSampleCoverage) { | |||
1652 | uint64_t Used = CoverageTracker.getTotalUsedSamples(); | |||
1653 | uint64_t Total = CoverageTracker.countBodySamples(Samples, PSI); | |||
1654 | unsigned Coverage = CoverageTracker.computeCoverage(Used, Total); | |||
1655 | if (Coverage < SampleProfileSampleCoverage) { | |||
1656 | F.getContext().diagnose(DiagnosticInfoSampleProfile( | |||
1657 | F.getSubprogram()->getFilename(), getFunctionLoc(F), | |||
1658 | Twine(Used) + " of " + Twine(Total) + " available profile samples (" + | |||
1659 | Twine(Coverage) + "%) were applied", | |||
1660 | DS_Warning)); | |||
1661 | } | |||
1662 | } | |||
1663 | return Changed; | |||
1664 | } | |||
1665 | ||||
1666 | char SampleProfileLoaderLegacyPass::ID = 0; | |||
1667 | ||||
1668 | INITIALIZE_PASS_BEGIN(SampleProfileLoaderLegacyPass, "sample-profile",static void *initializeSampleProfileLoaderLegacyPassPassOnce( PassRegistry &Registry) { | |||
1669 | "Sample Profile loader", false, false)static void *initializeSampleProfileLoaderLegacyPassPassOnce( PassRegistry &Registry) { | |||
1670 | INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry); | |||
1671 | INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)initializeTargetTransformInfoWrapperPassPass(Registry); | |||
1672 | INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)initializeProfileSummaryInfoWrapperPassPass(Registry); | |||
1673 | INITIALIZE_PASS_END(SampleProfileLoaderLegacyPass, "sample-profile",PassInfo *PI = new PassInfo( "Sample Profile loader", "sample-profile" , &SampleProfileLoaderLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<SampleProfileLoaderLegacyPass>), false , false); Registry.registerPass(*PI, true); return PI; } static llvm::once_flag InitializeSampleProfileLoaderLegacyPassPassFlag ; void llvm::initializeSampleProfileLoaderLegacyPassPass(PassRegistry &Registry) { llvm::call_once(InitializeSampleProfileLoaderLegacyPassPassFlag , initializeSampleProfileLoaderLegacyPassPassOnce, std::ref(Registry )); } | |||
1674 | "Sample Profile loader", false, false)PassInfo *PI = new PassInfo( "Sample Profile loader", "sample-profile" , &SampleProfileLoaderLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<SampleProfileLoaderLegacyPass>), false , false); Registry.registerPass(*PI, true); return PI; } static llvm::once_flag InitializeSampleProfileLoaderLegacyPassPassFlag ; void llvm::initializeSampleProfileLoaderLegacyPassPass(PassRegistry &Registry) { llvm::call_once(InitializeSampleProfileLoaderLegacyPassPassFlag , initializeSampleProfileLoaderLegacyPassPassOnce, std::ref(Registry )); } | |||
1675 | ||||
1676 | bool SampleProfileLoader::doInitialization(Module &M) { | |||
1677 | auto &Ctx = M.getContext(); | |||
1678 | auto ReaderOrErr = SampleProfileReader::create(Filename, Ctx); | |||
1679 | if (std::error_code EC = ReaderOrErr.getError()) { | |||
1680 | std::string Msg = "Could not open profile: " + EC.message(); | |||
1681 | Ctx.diagnose(DiagnosticInfoSampleProfile(Filename, Msg)); | |||
1682 | return false; | |||
1683 | } | |||
1684 | Reader = std::move(ReaderOrErr.get()); | |||
1685 | Reader->collectFuncsFrom(M); | |||
1686 | ProfileIsValid = (Reader->read() == sampleprof_error::success); | |||
1687 | PSL = Reader->getProfileSymbolList(); | |||
1688 | ||||
1689 | // While profile-sample-accurate is on, ignore symbol list. | |||
1690 | ProfAccForSymsInList = | |||
1691 | ProfileAccurateForSymsInList && PSL && !ProfileSampleAccurate; | |||
1692 | if (ProfAccForSymsInList
| |||
1693 | NamesInProfile.clear(); | |||
1694 | if (auto NameTable = Reader->getNameTable()) | |||
1695 | NamesInProfile.insert(NameTable->begin(), NameTable->end()); | |||
1696 | } | |||
1697 | ||||
1698 | if (!RemappingFilename.empty()) { | |||
1699 | // Apply profile remappings to the loaded profile data if requested. | |||
1700 | // For now, we only support remapping symbols encoded using the Itanium | |||
1701 | // C++ ABI's name mangling scheme. | |||
1702 | ReaderOrErr = SampleProfileReaderItaniumRemapper::create( | |||
1703 | RemappingFilename, Ctx, std::move(Reader)); | |||
1704 | if (std::error_code EC = ReaderOrErr.getError()) { | |||
1705 | std::string Msg = "Could not open profile remapping file: " + EC.message(); | |||
1706 | Ctx.diagnose(DiagnosticInfoSampleProfile(Filename, Msg)); | |||
1707 | return false; | |||
1708 | } | |||
1709 | Reader = std::move(ReaderOrErr.get()); | |||
1710 | ProfileIsValid = (Reader->read() == sampleprof_error::success); | |||
1711 | } | |||
1712 | return true; | |||
1713 | } | |||
1714 | ||||
1715 | ModulePass *llvm::createSampleProfileLoaderPass() { | |||
1716 | return new SampleProfileLoaderLegacyPass(); | |||
1717 | } | |||
1718 | ||||
1719 | ModulePass *llvm::createSampleProfileLoaderPass(StringRef Name) { | |||
1720 | return new SampleProfileLoaderLegacyPass(Name); | |||
1721 | } | |||
1722 | ||||
1723 | bool SampleProfileLoader::runOnModule(Module &M, ModuleAnalysisManager *AM, | |||
1724 | ProfileSummaryInfo *_PSI) { | |||
1725 | GUIDToFuncNameMapper Mapper(M, *Reader, GUIDToFuncNameMap); | |||
| ||||
1726 | if (!ProfileIsValid) | |||
1727 | return false; | |||
1728 | ||||
1729 | PSI = _PSI; | |||
1730 | if (M.getProfileSummary(/* IsCS */ false) == nullptr) | |||
1731 | M.setProfileSummary(Reader->getSummary().getMD(M.getContext()), | |||
1732 | ProfileSummary::PSK_Sample); | |||
1733 | ||||
1734 | // Compute the total number of samples collected in this profile. | |||
1735 | for (const auto &I : Reader->getProfiles()) | |||
1736 | TotalCollectedSamples += I.second.getTotalSamples(); | |||
1737 | ||||
1738 | // Populate the symbol map. | |||
1739 | for (const auto &N_F : M.getValueSymbolTable()) { | |||
1740 | StringRef OrigName = N_F.getKey(); | |||
1741 | Function *F = dyn_cast<Function>(N_F.getValue()); | |||
1742 | if (F == nullptr) | |||
1743 | continue; | |||
1744 | SymbolMap[OrigName] = F; | |||
1745 | auto pos = OrigName.find('.'); | |||
1746 | if (pos != StringRef::npos) { | |||
1747 | StringRef NewName = OrigName.substr(0, pos); | |||
1748 | auto r = SymbolMap.insert(std::make_pair(NewName, F)); | |||
1749 | // Failiing to insert means there is already an entry in SymbolMap, | |||
1750 | // thus there are multiple functions that are mapped to the same | |||
1751 | // stripped name. In this case of name conflicting, set the value | |||
1752 | // to nullptr to avoid confusion. | |||
1753 | if (!r.second) | |||
1754 | r.first->second = nullptr; | |||
1755 | } | |||
1756 | } | |||
1757 | ||||
1758 | bool retval = false; | |||
1759 | for (auto &F : M) | |||
1760 | if (!F.isDeclaration()) { | |||
1761 | clearFunctionData(); | |||
1762 | retval |= runOnFunction(F, AM); | |||
1763 | } | |||
1764 | ||||
1765 | // Account for cold calls not inlined.... | |||
1766 | for (const std::pair<Function *, NotInlinedProfileInfo> &pair : | |||
1767 | notInlinedCallInfo) | |||
1768 | updateProfileCallee(pair.first, pair.second.entryCount); | |||
1769 | ||||
1770 | return retval; | |||
1771 | } | |||
1772 | ||||
1773 | bool SampleProfileLoaderLegacyPass::runOnModule(Module &M) { | |||
1774 | ACT = &getAnalysis<AssumptionCacheTracker>(); | |||
1775 | TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>(); | |||
1776 | ProfileSummaryInfo *PSI = | |||
1777 | &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI(); | |||
1778 | return SampleLoader.runOnModule(M, nullptr, PSI); | |||
1779 | } | |||
1780 | ||||
1781 | bool SampleProfileLoader::runOnFunction(Function &F, ModuleAnalysisManager *AM) { | |||
1782 | ||||
1783 | DILocation2SampleMap.clear(); | |||
1784 | // By default the entry count is initialized to -1, which will be treated | |||
1785 | // conservatively by getEntryCount as the same as unknown (None). This is | |||
1786 | // to avoid newly added code to be treated as cold. If we have samples | |||
1787 | // this will be overwritten in emitAnnotations. | |||
1788 | uint64_t initialEntryCount = -1; | |||
1789 | ||||
1790 | ProfAccForSymsInList = ProfileAccurateForSymsInList && PSL; | |||
1791 | if (ProfileSampleAccurate || F.hasFnAttribute("profile-sample-accurate")) { | |||
1792 | // initialize all the function entry counts to 0. It means all the | |||
1793 | // functions without profile will be regarded as cold. | |||
1794 | initialEntryCount = 0; | |||
1795 | // profile-sample-accurate is a user assertion which has a higher precedence | |||
1796 | // than symbol list. When profile-sample-accurate is on, ignore symbol list. | |||
1797 | ProfAccForSymsInList = false; | |||
1798 | } | |||
1799 | ||||
1800 | // PSL -- profile symbol list include all the symbols in sampled binary. | |||
1801 | // If ProfileAccurateForSymsInList is enabled, PSL is used to treat | |||
1802 | // old functions without samples being cold, without having to worry | |||
1803 | // about new and hot functions being mistakenly treated as cold. | |||
1804 | if (ProfAccForSymsInList) { | |||
1805 | // Initialize the entry count to 0 for functions in the list. | |||
1806 | if (PSL->contains(F.getName())) | |||
1807 | initialEntryCount = 0; | |||
1808 | ||||
1809 | // Function in the symbol list but without sample will be regarded as | |||
1810 | // cold. To minimize the potential negative performance impact it could | |||
1811 | // have, we want to be a little conservative here saying if a function | |||
1812 | // shows up in the profile, no matter as outline function, inline instance | |||
1813 | // or call targets, treat the function as not being cold. This will handle | |||
1814 | // the cases such as most callsites of a function are inlined in sampled | |||
1815 | // binary but not inlined in current build (because of source code drift, | |||
1816 | // imprecise debug information, or the callsites are all cold individually | |||
1817 | // but not cold accumulatively...), so the outline function showing up as | |||
1818 | // cold in sampled binary will actually not be cold after current build. | |||
1819 | StringRef CanonName = FunctionSamples::getCanonicalFnName(F); | |||
1820 | if (NamesInProfile.count(CanonName)) | |||
1821 | initialEntryCount = -1; | |||
1822 | } | |||
1823 | ||||
1824 | F.setEntryCount(ProfileCount(initialEntryCount, Function::PCT_Real)); | |||
1825 | std::unique_ptr<OptimizationRemarkEmitter> OwnedORE; | |||
1826 | if (AM) { | |||
1827 | auto &FAM = | |||
1828 | AM->getResult<FunctionAnalysisManagerModuleProxy>(*F.getParent()) | |||
1829 | .getManager(); | |||
1830 | ORE = &FAM.getResult<OptimizationRemarkEmitterAnalysis>(F); | |||
1831 | } else { | |||
1832 | OwnedORE = std::make_unique<OptimizationRemarkEmitter>(&F); | |||
1833 | ORE = OwnedORE.get(); | |||
1834 | } | |||
1835 | Samples = Reader->getSamplesFor(F); | |||
1836 | if (Samples && !Samples->empty()) | |||
1837 | return emitAnnotations(F); | |||
1838 | return false; | |||
1839 | } | |||
1840 | ||||
1841 | PreservedAnalyses SampleProfileLoaderPass::run(Module &M, | |||
1842 | ModuleAnalysisManager &AM) { | |||
1843 | FunctionAnalysisManager &FAM = | |||
1844 | AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager(); | |||
1845 | ||||
1846 | auto GetAssumptionCache = [&](Function &F) -> AssumptionCache & { | |||
1847 | return FAM.getResult<AssumptionAnalysis>(F); | |||
1848 | }; | |||
1849 | auto GetTTI = [&](Function &F) -> TargetTransformInfo & { | |||
1850 | return FAM.getResult<TargetIRAnalysis>(F); | |||
1851 | }; | |||
1852 | ||||
1853 | SampleProfileLoader SampleLoader( | |||
1854 | ProfileFileName.empty() ? SampleProfileFile : ProfileFileName, | |||
| ||||
1855 | ProfileRemappingFileName.empty() ? SampleProfileRemappingFile | |||
1856 | : ProfileRemappingFileName, | |||
1857 | IsThinLTOPreLink, GetAssumptionCache, GetTTI); | |||
1858 | ||||
1859 | SampleLoader.doInitialization(M); | |||
1860 | ||||
1861 | ProfileSummaryInfo *PSI = &AM.getResult<ProfileSummaryAnalysis>(M); | |||
1862 | if (!SampleLoader.runOnModule(M, &AM, PSI)) | |||
1863 | return PreservedAnalyses::all(); | |||
1864 | ||||
1865 | return PreservedAnalyses::none(); | |||
1866 | } |