1 //=-- SampleProf.h - Sampling profiling format support --------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains common definitions used in the reading and writing of
11 // sample profile data.
13 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_PROFILEDATA_SAMPLEPROF_H_
15 #define LLVM_PROFILEDATA_SAMPLEPROF_H_
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include <system_error>
26 const std::error_category &sampleprof_category();
28 enum class sampleprof_error {
38 inline std::error_code make_error_code(sampleprof_error E) {
39 return std::error_code(static_cast<int>(E), sampleprof_category());
42 } // end namespace llvm
46 struct is_error_code_enum<llvm::sampleprof_error> : std::true_type {};
51 namespace sampleprof {
53 static inline uint64_t SPMagic() {
54 return uint64_t('S') << (64 - 8) | uint64_t('P') << (64 - 16) |
55 uint64_t('R') << (64 - 24) | uint64_t('O') << (64 - 32) |
56 uint64_t('F') << (64 - 40) | uint64_t('4') << (64 - 48) |
57 uint64_t('2') << (64 - 56) | uint64_t(0xff);
60 static inline uint64_t SPVersion() { return 100; }
62 /// \brief Represents the relative location of an instruction.
64 /// Instruction locations are specified by the line offset from the
65 /// beginning of the function (marked by the line where the function
66 /// header is) and the discriminator value within that line.
68 /// The discriminator value is useful to distinguish instructions
69 /// that are on the same line but belong to different basic blocks
70 /// (e.g., the two post-increment instructions in "if (p) x++; else y++;").
72 LineLocation(int L, unsigned D) : LineOffset(L), Discriminator(D) {}
74 unsigned Discriminator;
77 } // End namespace sampleprof
79 template <> struct DenseMapInfo<sampleprof::LineLocation> {
80 typedef DenseMapInfo<int> OffsetInfo;
81 typedef DenseMapInfo<unsigned> DiscriminatorInfo;
82 static inline sampleprof::LineLocation getEmptyKey() {
83 return sampleprof::LineLocation(OffsetInfo::getEmptyKey(),
84 DiscriminatorInfo::getEmptyKey());
86 static inline sampleprof::LineLocation getTombstoneKey() {
87 return sampleprof::LineLocation(OffsetInfo::getTombstoneKey(),
88 DiscriminatorInfo::getTombstoneKey());
90 static inline unsigned getHashValue(sampleprof::LineLocation Val) {
91 return DenseMapInfo<std::pair<int, unsigned>>::getHashValue(
92 std::pair<int, unsigned>(Val.LineOffset, Val.Discriminator));
94 static inline bool isEqual(sampleprof::LineLocation LHS,
95 sampleprof::LineLocation RHS) {
96 return LHS.LineOffset == RHS.LineOffset &&
97 LHS.Discriminator == RHS.Discriminator;
101 namespace sampleprof {
103 /// \brief Representation of a single sample record.
105 /// A sample record is represented by a positive integer value, which
106 /// indicates how frequently was the associated line location executed.
108 /// Additionally, if the associated location contains a function call,
109 /// the record will hold a list of all the possible called targets. For
110 /// direct calls, this will be the exact function being invoked. For
111 /// indirect calls (function pointers, virtual table dispatch), this
112 /// will be a list of one or more functions.
115 typedef StringMap<unsigned> CallTargetMap;
117 SampleRecord() : NumSamples(0), CallTargets() {}
119 /// \brief Increment the number of samples for this record by \p S.
121 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping
122 /// around unsigned integers.
123 void addSamples(unsigned S) {
124 if (NumSamples <= std::numeric_limits<unsigned>::max() - S)
127 NumSamples = std::numeric_limits<unsigned>::max();
130 /// \brief Add called function \p F with samples \p S.
132 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping
133 /// around unsigned integers.
134 void addCalledTarget(StringRef F, unsigned S) {
135 unsigned &TargetSamples = CallTargets[F];
136 if (TargetSamples <= std::numeric_limits<unsigned>::max() - S)
139 TargetSamples = std::numeric_limits<unsigned>::max();
142 /// \brief Return true if this sample record contains function calls.
143 bool hasCalls() const { return CallTargets.size() > 0; }
145 unsigned getSamples() const { return NumSamples; }
146 const CallTargetMap &getCallTargets() const { return CallTargets; }
148 /// \brief Merge the samples in \p Other into this record.
149 void merge(const SampleRecord &Other) {
150 addSamples(Other.getSamples());
151 for (const auto &I : Other.getCallTargets())
152 addCalledTarget(I.first(), I.second);
157 CallTargetMap CallTargets;
160 typedef DenseMap<LineLocation, SampleRecord> BodySampleMap;
162 /// \brief Representation of the samples collected for a function.
164 /// This data structure contains all the collected samples for the body
165 /// of a function. Each sample corresponds to a LineLocation instance
166 /// within the body of the function.
167 class FunctionSamples {
169 FunctionSamples() : TotalSamples(0), TotalHeadSamples(0) {}
170 void print(raw_ostream &OS = dbgs());
171 void addTotalSamples(unsigned Num) { TotalSamples += Num; }
172 void addHeadSamples(unsigned Num) { TotalHeadSamples += Num; }
173 void addBodySamples(int LineOffset, unsigned Discriminator, unsigned Num) {
174 assert(LineOffset >= 0);
175 // When dealing with instruction weights, we use the value
176 // zero to indicate the absence of a sample. If we read an
177 // actual zero from the profile file, use the value 1 to
178 // avoid the confusion later on.
181 BodySamples[LineLocation(LineOffset, Discriminator)].addSamples(Num);
183 void addCalledTargetSamples(int LineOffset, unsigned Discriminator,
184 std::string FName, unsigned Num) {
185 assert(LineOffset >= 0);
186 BodySamples[LineLocation(LineOffset, Discriminator)].addCalledTarget(FName,
190 /// \brief Return the sample record at the given location.
191 /// Each location is specified by \p LineOffset and \p Discriminator.
192 SampleRecord &sampleRecordAt(const LineLocation &Loc) {
193 return BodySamples[Loc];
196 /// \brief Return the number of samples collected at the given location.
197 /// Each location is specified by \p LineOffset and \p Discriminator.
198 unsigned samplesAt(int LineOffset, unsigned Discriminator) {
199 return sampleRecordAt(LineLocation(LineOffset, Discriminator)).getSamples();
202 bool empty() const { return BodySamples.empty(); }
204 /// \brief Return the total number of samples collected inside the function.
205 unsigned getTotalSamples() const { return TotalSamples; }
207 /// \brief Return the total number of samples collected at the head of the
209 unsigned getHeadSamples() const { return TotalHeadSamples; }
211 /// \brief Return all the samples collected in the body of the function.
212 const BodySampleMap &getBodySamples() const { return BodySamples; }
214 /// \brief Merge the samples in \p Other into this one.
215 void merge(const FunctionSamples &Other) {
216 addTotalSamples(Other.getTotalSamples());
217 addHeadSamples(Other.getHeadSamples());
218 for (const auto &I : Other.getBodySamples()) {
219 const LineLocation &Loc = I.first;
220 const SampleRecord &Rec = I.second;
221 sampleRecordAt(Loc).merge(Rec);
226 /// \brief Total number of samples collected inside this function.
228 /// Samples are cumulative, they include all the samples collected
229 /// inside this function and all its inlined callees.
230 unsigned TotalSamples;
232 /// \brief Total number of samples collected at the head of the function.
233 unsigned TotalHeadSamples;
235 /// \brief Map instruction locations to collected samples.
237 /// Each entry in this map contains the number of samples
238 /// collected at the corresponding line offset. All line locations
239 /// are an offset from the start of the function.
240 BodySampleMap BodySamples;
243 } // End namespace sampleprof
245 } // End namespace llvm
247 #endif // LLVM_PROFILEDATA_SAMPLEPROF_H_