5c70b316fbc6593f40719e765206bb8275651f8e
1 //=-- SampleProf.h - Sampling profiling format support --------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains common definitions used in the reading and writing of
11 // sample profile data.
12 //
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"
23 #include <system_error>
25 namespace llvm {
27 const std::error_category &sampleprof_category();
29 enum class sampleprof_error {
30 success = 0,
31 bad_magic,
32 unsupported_version,
33 too_large,
34 truncated,
35 malformed,
36 unrecognized_format
37 };
39 inline std::error_code make_error_code(sampleprof_error E) {
40 return std::error_code(static_cast<int>(E), sampleprof_category());
41 }
43 } // end namespace llvm
45 namespace std {
46 template <>
47 struct is_error_code_enum<llvm::sampleprof_error> : std::true_type {};
48 }
50 namespace llvm {
52 namespace sampleprof {
54 static inline uint64_t SPMagic() {
55 return uint64_t('S') << (64 - 8) | uint64_t('P') << (64 - 16) |
56 uint64_t('R') << (64 - 24) | uint64_t('O') << (64 - 32) |
57 uint64_t('F') << (64 - 40) | uint64_t('4') << (64 - 48) |
58 uint64_t('2') << (64 - 56) | uint64_t(0xff);
59 }
61 static inline uint64_t SPVersion() { return 100; }
63 /// \brief Represents the relative location of an instruction.
64 ///
65 /// Instruction locations are specified by the line offset from the
66 /// beginning of the function (marked by the line where the function
67 /// header is) and the discriminator value within that line.
68 ///
69 /// The discriminator value is useful to distinguish instructions
70 /// that are on the same line but belong to different basic blocks
71 /// (e.g., the two post-increment instructions in "if (p) x++; else y++;").
72 struct LineLocation {
73 LineLocation(int L, unsigned D) : LineOffset(L), Discriminator(D) {}
74 int LineOffset;
75 unsigned Discriminator;
76 };
78 } // End namespace sampleprof
80 template <> struct DenseMapInfo<sampleprof::LineLocation> {
81 typedef DenseMapInfo<int> OffsetInfo;
82 typedef DenseMapInfo<unsigned> DiscriminatorInfo;
83 static inline sampleprof::LineLocation getEmptyKey() {
84 return sampleprof::LineLocation(OffsetInfo::getEmptyKey(),
85 DiscriminatorInfo::getEmptyKey());
86 }
87 static inline sampleprof::LineLocation getTombstoneKey() {
88 return sampleprof::LineLocation(OffsetInfo::getTombstoneKey(),
89 DiscriminatorInfo::getTombstoneKey());
90 }
91 static inline unsigned getHashValue(sampleprof::LineLocation Val) {
92 return DenseMapInfo<std::pair<int, unsigned>>::getHashValue(
93 std::pair<int, unsigned>(Val.LineOffset, Val.Discriminator));
94 }
95 static inline bool isEqual(sampleprof::LineLocation LHS,
96 sampleprof::LineLocation RHS) {
97 return LHS.LineOffset == RHS.LineOffset &&
98 LHS.Discriminator == RHS.Discriminator;
99 }
100 };
102 namespace sampleprof {
104 /// \brief Representation of a single sample record.
105 ///
106 /// A sample record is represented by a positive integer value, which
107 /// indicates how frequently was the associated line location executed.
108 ///
109 /// Additionally, if the associated location contains a function call,
110 /// the record will hold a list of all the possible called targets. For
111 /// direct calls, this will be the exact function being invoked. For
112 /// indirect calls (function pointers, virtual table dispatch), this
113 /// will be a list of one or more functions.
114 class SampleRecord {
115 public:
116 typedef StringMap<unsigned> CallTargetMap;
118 SampleRecord() : NumSamples(0), CallTargets() {}
120 /// \brief Increment the number of samples for this record by \p S.
121 ///
122 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping
123 /// around unsigned integers.
124 void addSamples(unsigned S) {
125 if (NumSamples <= std::numeric_limits<unsigned>::max() - S)
126 NumSamples += S;
127 else
128 NumSamples = std::numeric_limits<unsigned>::max();
129 }
131 /// \brief Add called function \p F with samples \p S.
132 ///
133 /// Sample counts accumulate using saturating arithmetic, to avoid wrapping
134 /// around unsigned integers.
135 void addCalledTarget(StringRef F, unsigned S) {
136 unsigned &TargetSamples = CallTargets[F];
137 if (TargetSamples <= std::numeric_limits<unsigned>::max() - S)
138 TargetSamples += S;
139 else
140 TargetSamples = std::numeric_limits<unsigned>::max();
141 }
143 /// \brief Return true if this sample record contains function calls.
144 bool hasCalls() const { return CallTargets.size() > 0; }
146 unsigned getSamples() const { return NumSamples; }
147 const CallTargetMap &getCallTargets() const { return CallTargets; }
149 /// \brief Merge the samples in \p Other into this record.
150 void merge(const SampleRecord &Other) {
151 addSamples(Other.getSamples());
152 for (const auto &I : Other.getCallTargets())
153 addCalledTarget(I.first(), I.second);
154 }
156 private:
157 unsigned NumSamples;
158 CallTargetMap CallTargets;
159 };
161 typedef DenseMap<LineLocation, SampleRecord> BodySampleMap;
163 /// \brief Representation of the samples collected for a function.
164 ///
165 /// This data structure contains all the collected samples for the body
166 /// of a function. Each sample corresponds to a LineLocation instance
167 /// within the body of the function.
168 class FunctionSamples {
169 public:
170 FunctionSamples() : TotalSamples(0), TotalHeadSamples(0) {}
171 void print(raw_ostream &OS = dbgs());
172 void addTotalSamples(unsigned Num) { TotalSamples += Num; }
173 void addHeadSamples(unsigned Num) { TotalHeadSamples += Num; }
174 void addBodySamples(int LineOffset, unsigned Discriminator, unsigned Num) {
175 assert(LineOffset >= 0);
176 // When dealing with instruction weights, we use the value
177 // zero to indicate the absence of a sample. If we read an
178 // actual zero from the profile file, use the value 1 to
179 // avoid the confusion later on.
180 if (Num == 0)
181 Num = 1;
182 BodySamples[LineLocation(LineOffset, Discriminator)].addSamples(Num);
183 }
184 void addCalledTargetSamples(int LineOffset, unsigned Discriminator,
185 std::string FName, unsigned Num) {
186 assert(LineOffset >= 0);
187 BodySamples[LineLocation(LineOffset, Discriminator)].addCalledTarget(FName,
188 Num);
189 }
191 /// \brief Return the sample record at the given location.
192 /// Each location is specified by \p LineOffset and \p Discriminator.
193 SampleRecord &sampleRecordAt(const LineLocation &Loc) {
194 return BodySamples[Loc];
195 }
197 /// \brief Return the number of samples collected at the given location.
198 /// Each location is specified by \p LineOffset and \p Discriminator.
199 unsigned samplesAt(int LineOffset, unsigned Discriminator) {
200 return sampleRecordAt(LineLocation(LineOffset, Discriminator)).getSamples();
201 }
203 bool empty() const { return BodySamples.empty(); }
205 /// \brief Return the total number of samples collected inside the function.
206 unsigned getTotalSamples() const { return TotalSamples; }
208 /// \brief Return the total number of samples collected at the head of the
209 /// function.
210 unsigned getHeadSamples() const { return TotalHeadSamples; }
212 /// \brief Return all the samples collected in the body of the function.
213 const BodySampleMap &getBodySamples() const { return BodySamples; }
215 /// \brief Merge the samples in \p Other into this one.
216 void merge(const FunctionSamples &Other) {
217 addTotalSamples(Other.getTotalSamples());
218 addHeadSamples(Other.getHeadSamples());
219 for (const auto &I : Other.getBodySamples()) {
220 const LineLocation &Loc = I.first;
221 const SampleRecord &Rec = I.second;
222 sampleRecordAt(Loc).merge(Rec);
223 }
224 }
226 private:
227 /// \brief Total number of samples collected inside this function.
228 ///
229 /// Samples are cumulative, they include all the samples collected
230 /// inside this function and all its inlined callees.
231 unsigned TotalSamples;
233 /// \brief Total number of samples collected at the head of the function.
234 unsigned TotalHeadSamples;
236 /// \brief Map instruction locations to collected samples.
237 ///
238 /// Each entry in this map contains the number of samples
239 /// collected at the corresponding line offset. All line locations
240 /// are an offset from the start of the function.
241 BodySampleMap BodySamples;
242 };
244 } // End namespace sampleprof
246 } // End namespace llvm
248 #endif // LLVM_PROFILEDATA_SAMPLEPROF_H_