1 //===- SampleProf.h - Sampling profiling format support ---------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains common definitions used in the reading and writing of
11 // sample profile data.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_PROFILEDATA_SAMPLEPROF_H
16 #define LLVM_PROFILEDATA_SAMPLEPROF_H
18 #include "llvm/ADT/DenseSet.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/IR/Function.h"
23 #include "llvm/IR/GlobalValue.h"
24 #include "llvm/IR/Module.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/ErrorOr.h"
27 #include "llvm/Support/MathExtras.h"
32 #include <system_error>
39 const std::error_category &sampleprof_category();
41 enum class sampleprof_error {
49 unsupported_writing_format,
55 inline std::error_code make_error_code(sampleprof_error E) {
56 return std::error_code(static_cast<int>(E), sampleprof_category());
59 inline sampleprof_error MergeResult(sampleprof_error &Accumulator,
60 sampleprof_error Result) {
61 // Prefer first error encountered as later errors may be secondary effects of
62 // the initial problem.
63 if (Accumulator == sampleprof_error::success &&
64 Result != sampleprof_error::success)
69 } // end namespace llvm
74 struct is_error_code_enum<llvm::sampleprof_error> : std::true_type {};
76 } // end namespace std
79 namespace sampleprof {
81 static inline uint64_t SPMagic() {
82 return uint64_t('S') << (64 - 8) | uint64_t('P') << (64 - 16) |
83 uint64_t('R') << (64 - 24) | uint64_t('O') << (64 - 32) |
84 uint64_t('F') << (64 - 40) | uint64_t('4') << (64 - 48) |
85 uint64_t('2') << (64 - 56) | uint64_t(0xff);
88 static inline uint64_t SPVersion() { return 103; }
90 /// Represents the relative location of an instruction.
92 /// Instruction locations are specified by the line offset from the
93 /// beginning of the function (marked by the line where the function
94 /// header is) and the discriminator value within that line.
96 /// The discriminator value is useful to distinguish instructions
97 /// that are on the same line but belong to different basic blocks
98 /// (e.g., the two post-increment instructions in "if (p) x++; else y++;").
100 LineLocation(uint32_t L, uint32_t D) : LineOffset(L), Discriminator(D) {}
102 void print(raw_ostream &OS) const;
105 bool operator<(const LineLocation &O) const {
106 return LineOffset < O.LineOffset ||
107 (LineOffset == O.LineOffset && Discriminator < O.Discriminator);
111 uint32_t Discriminator;
114 raw_ostream &operator<<(raw_ostream &OS, const LineLocation &Loc);
116 /// Representation of a single sample record.
118 /// A sample record is represented by a positive integer value, which
119 /// indicates how frequently was the associated line location executed.
121 /// Additionally, if the associated location contains a function call,
122 /// the record will hold a list of all the possible called targets. For
123 /// direct calls, this will be the exact function being invoked. For
124 /// indirect calls (function pointers, virtual table dispatch), this
125 /// will be a list of one or more functions.
128 using CallTargetMap = StringMap<uint64_t>;
130 SampleRecord() = default;
132 /// Increment the number of samples for this record by \p S.
133 /// Optionally scale sample count \p S by \p Weight.
135 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping
136 /// around unsigned integers.
137 sampleprof_error addSamples(uint64_t S, uint64_t Weight = 1) {
139 NumSamples = SaturatingMultiplyAdd(S, Weight, NumSamples, &Overflowed);
140 return Overflowed ? sampleprof_error::counter_overflow
141 : sampleprof_error::success;
144 /// Add called function \p F with samples \p S.
145 /// Optionally scale sample count \p S by \p Weight.
147 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping
148 /// around unsigned integers.
149 sampleprof_error addCalledTarget(StringRef F, uint64_t S,
150 uint64_t Weight = 1) {
151 uint64_t &TargetSamples = CallTargets[F];
154 SaturatingMultiplyAdd(S, Weight, TargetSamples, &Overflowed);
155 return Overflowed ? sampleprof_error::counter_overflow
156 : sampleprof_error::success;
159 /// Return true if this sample record contains function calls.
160 bool hasCalls() const { return !CallTargets.empty(); }
162 uint64_t getSamples() const { return NumSamples; }
163 const CallTargetMap &getCallTargets() const { return CallTargets; }
165 /// Merge the samples in \p Other into this record.
166 /// Optionally scale sample counts by \p Weight.
167 sampleprof_error merge(const SampleRecord &Other, uint64_t Weight = 1) {
168 sampleprof_error Result = addSamples(Other.getSamples(), Weight);
169 for (const auto &I : Other.getCallTargets()) {
170 MergeResult(Result, addCalledTarget(I.first(), I.second, Weight));
175 void print(raw_ostream &OS, unsigned Indent) const;
179 uint64_t NumSamples = 0;
180 CallTargetMap CallTargets;
183 raw_ostream &operator<<(raw_ostream &OS, const SampleRecord &Sample);
185 class FunctionSamples;
187 using BodySampleMap = std::map<LineLocation, SampleRecord>;
188 using FunctionSamplesMap = StringMap<FunctionSamples>;
189 using CallsiteSampleMap = std::map<LineLocation, FunctionSamplesMap>;
191 /// Representation of the samples collected for a function.
193 /// This data structure contains all the collected samples for the body
194 /// of a function. Each sample corresponds to a LineLocation instance
195 /// within the body of the function.
196 class FunctionSamples {
198 FunctionSamples() = default;
200 void print(raw_ostream &OS = dbgs(), unsigned Indent = 0) const;
203 sampleprof_error addTotalSamples(uint64_t Num, uint64_t Weight = 1) {
206 SaturatingMultiplyAdd(Num, Weight, TotalSamples, &Overflowed);
207 return Overflowed ? sampleprof_error::counter_overflow
208 : sampleprof_error::success;
211 sampleprof_error addHeadSamples(uint64_t Num, uint64_t Weight = 1) {
214 SaturatingMultiplyAdd(Num, Weight, TotalHeadSamples, &Overflowed);
215 return Overflowed ? sampleprof_error::counter_overflow
216 : sampleprof_error::success;
219 sampleprof_error addBodySamples(uint32_t LineOffset, uint32_t Discriminator,
220 uint64_t Num, uint64_t Weight = 1) {
221 return BodySamples[LineLocation(LineOffset, Discriminator)].addSamples(
225 sampleprof_error addCalledTargetSamples(uint32_t LineOffset,
226 uint32_t Discriminator,
227 const std::string &FName,
228 uint64_t Num, uint64_t Weight = 1) {
229 return BodySamples[LineLocation(LineOffset, Discriminator)].addCalledTarget(
233 /// Return the number of samples collected at the given location.
234 /// Each location is specified by \p LineOffset and \p Discriminator.
235 /// If the location is not found in profile, return error.
236 ErrorOr<uint64_t> findSamplesAt(uint32_t LineOffset,
237 uint32_t Discriminator) const {
238 const auto &ret = BodySamples.find(LineLocation(LineOffset, Discriminator));
239 if (ret == BodySamples.end())
240 return std::error_code();
242 return ret->second.getSamples();
245 /// Returns the call target map collected at a given location.
246 /// Each location is specified by \p LineOffset and \p Discriminator.
247 /// If the location is not found in profile, return error.
248 ErrorOr<SampleRecord::CallTargetMap>
249 findCallTargetMapAt(uint32_t LineOffset, uint32_t Discriminator) const {
250 const auto &ret = BodySamples.find(LineLocation(LineOffset, Discriminator));
251 if (ret == BodySamples.end())
252 return std::error_code();
253 return ret->second.getCallTargets();
256 /// Return the function samples at the given callsite location.
257 FunctionSamplesMap &functionSamplesAt(const LineLocation &Loc) {
258 return CallsiteSamples[Loc];
261 /// Returns the FunctionSamplesMap at the given \p Loc.
262 const FunctionSamplesMap *
263 findFunctionSamplesMapAt(const LineLocation &Loc) const {
264 auto iter = CallsiteSamples.find(Loc);
265 if (iter == CallsiteSamples.end())
267 return &iter->second;
270 /// Returns a pointer to FunctionSamples at the given callsite location \p Loc
271 /// with callee \p CalleeName. If no callsite can be found, relax the
272 /// restriction to return the FunctionSamples at callsite location \p Loc
273 /// with the maximum total sample count.
274 const FunctionSamples *findFunctionSamplesAt(const LineLocation &Loc,
275 StringRef CalleeName) const {
276 auto iter = CallsiteSamples.find(Loc);
277 if (iter == CallsiteSamples.end())
279 auto FS = iter->second.find(CalleeName);
280 if (FS != iter->second.end())
281 return &FS->getValue();
282 // If we cannot find exact match of the callee name, return the FS with
283 // the max total count.
284 uint64_t MaxTotalSamples = 0;
285 const FunctionSamples *R = nullptr;
286 for (const auto &NameFS : iter->second)
287 if (NameFS.second.getTotalSamples() >= MaxTotalSamples) {
288 MaxTotalSamples = NameFS.second.getTotalSamples();
294 bool empty() const { return TotalSamples == 0; }
296 /// Return the total number of samples collected inside the function.
297 uint64_t getTotalSamples() const { return TotalSamples; }
299 /// Return the total number of samples collected at the head of the
301 uint64_t getHeadSamples() const { return TotalHeadSamples; }
303 /// Return all the samples collected in the body of the function.
304 const BodySampleMap &getBodySamples() const { return BodySamples; }
306 /// Return all the callsite samples collected in the body of the function.
307 const CallsiteSampleMap &getCallsiteSamples() const {
308 return CallsiteSamples;
311 /// Merge the samples in \p Other into this one.
312 /// Optionally scale samples by \p Weight.
313 sampleprof_error merge(const FunctionSamples &Other, uint64_t Weight = 1) {
314 sampleprof_error Result = sampleprof_error::success;
315 Name = Other.getName();
316 MergeResult(Result, addTotalSamples(Other.getTotalSamples(), Weight));
317 MergeResult(Result, addHeadSamples(Other.getHeadSamples(), Weight));
318 for (const auto &I : Other.getBodySamples()) {
319 const LineLocation &Loc = I.first;
320 const SampleRecord &Rec = I.second;
321 MergeResult(Result, BodySamples[Loc].merge(Rec, Weight));
323 for (const auto &I : Other.getCallsiteSamples()) {
324 const LineLocation &Loc = I.first;
325 FunctionSamplesMap &FSMap = functionSamplesAt(Loc);
326 for (const auto &Rec : I.second)
327 MergeResult(Result, FSMap[Rec.first()].merge(Rec.second, Weight));
332 /// Recursively traverses all children, if the corresponding function is
333 /// not defined in module \p M, and its total sample is no less than
334 /// \p Threshold, add its corresponding GUID to \p S.
335 void findImportedFunctions(DenseSet<GlobalValue::GUID> &S, const Module *M,
336 uint64_t Threshold) const {
337 if (TotalSamples <= Threshold)
339 Function *F = M->getFunction(Name);
340 if (!F || !F->getSubprogram())
341 S.insert(Function::getGUID(Name));
342 for (auto CS : CallsiteSamples)
343 for (const auto &NameFS : CS.second)
344 NameFS.second.findImportedFunctions(S, M, Threshold);
347 /// Set the name of the function.
348 void setName(StringRef FunctionName) { Name = FunctionName; }
350 /// Return the function name.
351 const StringRef &getName() const { return Name; }
354 /// Mangled name of the function.
357 /// Total number of samples collected inside this function.
359 /// Samples are cumulative, they include all the samples collected
360 /// inside this function and all its inlined callees.
361 uint64_t TotalSamples = 0;
363 /// Total number of samples collected at the head of the function.
364 /// This is an approximation of the number of calls made to this function
366 uint64_t TotalHeadSamples = 0;
368 /// Map instruction locations to collected samples.
370 /// Each entry in this map contains the number of samples
371 /// collected at the corresponding line offset. All line locations
372 /// are an offset from the start of the function.
373 BodySampleMap BodySamples;
375 /// Map call sites to collected samples for the called function.
377 /// Each entry in this map corresponds to all the samples
378 /// collected for the inlined function call at the given
379 /// location. For example, given:
387 /// If the bar() and baz() calls were inlined inside foo(), this
388 /// map will contain two entries. One for all the samples collected
389 /// in the call to bar() at line offset 1, the other for all the samples
390 /// collected in the call to baz() at line offset 8.
391 CallsiteSampleMap CallsiteSamples;
394 raw_ostream &operator<<(raw_ostream &OS, const FunctionSamples &FS);
396 /// Sort a LocationT->SampleT map by LocationT.
398 /// It produces a sorted list of <LocationT, SampleT> records by ascending
399 /// order of LocationT.
400 template <class LocationT, class SampleT> class SampleSorter {
402 using SamplesWithLoc = std::pair<const LocationT, SampleT>;
403 using SamplesWithLocList = SmallVector<const SamplesWithLoc *, 20>;
405 SampleSorter(const std::map<LocationT, SampleT> &Samples) {
406 for (const auto &I : Samples)
408 std::stable_sort(V.begin(), V.end(),
409 [](const SamplesWithLoc *A, const SamplesWithLoc *B) {
410 return A->first < B->first;
414 const SamplesWithLocList &get() const { return V; }
417 SamplesWithLocList V;
420 } // end namespace sampleprof
421 } // end namespace llvm
423 #endif // LLVM_PROFILEDATA_SAMPLEPROF_H