Line data Source code
1 : //===- SampleProfWriter.cpp - Write LLVM sample profile data --------------===//
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 implements the class that writes LLVM sample profiles. It
11 : // supports two file formats: text and binary. The textual representation
12 : // is useful for debugging and testing purposes. The binary representation
13 : // is more compact, resulting in smaller file sizes. However, they can
14 : // both be used interchangeably.
15 : //
16 : // See lib/ProfileData/SampleProfReader.cpp for documentation on each of the
17 : // supported formats.
18 : //
19 : //===----------------------------------------------------------------------===//
20 :
21 : #include "llvm/ProfileData/SampleProfWriter.h"
22 : #include "llvm/ADT/StringRef.h"
23 : #include "llvm/ProfileData/ProfileCommon.h"
24 : #include "llvm/ProfileData/SampleProf.h"
25 : #include "llvm/Support/Endian.h"
26 : #include "llvm/Support/EndianStream.h"
27 : #include "llvm/Support/ErrorOr.h"
28 : #include "llvm/Support/FileSystem.h"
29 : #include "llvm/Support/LEB128.h"
30 : #include "llvm/Support/MD5.h"
31 : #include "llvm/Support/raw_ostream.h"
32 : #include <algorithm>
33 : #include <cstdint>
34 : #include <memory>
35 : #include <set>
36 : #include <system_error>
37 : #include <utility>
38 : #include <vector>
39 :
40 : using namespace llvm;
41 : using namespace sampleprof;
42 :
43 : std::error_code
44 22 : SampleProfileWriter::write(const StringMap<FunctionSamples> &ProfileMap) {
45 22 : if (std::error_code EC = writeHeader(ProfileMap))
46 0 : return EC;
47 :
48 : // Sort the ProfileMap by total samples.
49 : typedef std::pair<StringRef, const FunctionSamples *> NameFunctionSamples;
50 : std::vector<NameFunctionSamples> V;
51 88 : for (const auto &I : ProfileMap)
52 44 : V.push_back(std::make_pair(I.getKey(), &I.second));
53 :
54 22 : std::stable_sort(
55 : V.begin(), V.end(),
56 : [](const NameFunctionSamples &A, const NameFunctionSamples &B) {
57 0 : if (A.second->getTotalSamples() == B.second->getTotalSamples())
58 0 : return A.first > B.first;
59 0 : return A.second->getTotalSamples() > B.second->getTotalSamples();
60 : });
61 :
62 66 : for (const auto &I : V) {
63 44 : if (std::error_code EC = write(*I.second))
64 0 : return EC;
65 : }
66 22 : return sampleprof_error::success;
67 : }
68 :
69 1 : std::error_code SampleProfileWriterCompactBinary::write(
70 : const StringMap<FunctionSamples> &ProfileMap) {
71 1 : if (std::error_code EC = SampleProfileWriter::write(ProfileMap))
72 0 : return EC;
73 1 : if (std::error_code EC = writeFuncOffsetTable())
74 0 : return EC;
75 1 : return sampleprof_error::success;
76 : }
77 :
78 : /// Write samples to a text file.
79 : ///
80 : /// Note: it may be tempting to implement this in terms of
81 : /// FunctionSamples::print(). Please don't. The dump functionality is intended
82 : /// for debugging and has no specified form.
83 : ///
84 : /// The format used here is more structured and deliberate because
85 : /// it needs to be parsed by the SampleProfileReaderText class.
86 50 : std::error_code SampleProfileWriterText::write(const FunctionSamples &S) {
87 : auto &OS = *OutputStream;
88 50 : OS << S.getName() << ":" << S.getTotalSamples();
89 50 : if (Indent == 0)
90 22 : OS << ":" << S.getHeadSamples();
91 50 : OS << "\n";
92 :
93 50 : SampleSorter<LineLocation, SampleRecord> SortedSamples(S.getBodySamples());
94 216 : for (const auto &I : SortedSamples.get()) {
95 166 : LineLocation Loc = I->first;
96 : const SampleRecord &Sample = I->second;
97 166 : OS.indent(Indent + 1);
98 166 : if (Loc.Discriminator == 0)
99 102 : OS << Loc.LineOffset << ": ";
100 : else
101 128 : OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
102 :
103 166 : OS << Sample.getSamples();
104 :
105 346 : for (const auto &J : Sample.getCallTargets())
106 14 : OS << " " << J.first() << ":" << J.second;
107 166 : OS << "\n";
108 : }
109 :
110 : SampleSorter<LineLocation, FunctionSamplesMap> SortedCallsiteSamples(
111 50 : S.getCallsiteSamples());
112 50 : Indent += 1;
113 76 : for (const auto &I : SortedCallsiteSamples.get())
114 54 : for (const auto &FS : I->second) {
115 28 : LineLocation Loc = I->first;
116 28 : const FunctionSamples &CalleeSamples = FS.second;
117 28 : OS.indent(Indent);
118 28 : if (Loc.Discriminator == 0)
119 4 : OS << Loc.LineOffset << ": ";
120 : else
121 48 : OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
122 28 : if (std::error_code EC = write(CalleeSamples))
123 0 : return EC;
124 : }
125 50 : Indent -= 1;
126 :
127 50 : return sampleprof_error::success;
128 : }
129 :
130 48 : std::error_code SampleProfileWriterBinary::writeNameIdx(StringRef FName) {
131 48 : const auto &ret = NameTable.find(FName);
132 48 : if (ret == NameTable.end())
133 0 : return sampleprof_error::truncated_name_table;
134 48 : encodeULEB128(ret->second, *OutputStream);
135 48 : return sampleprof_error::success;
136 : }
137 :
138 46 : void SampleProfileWriterBinary::addName(StringRef FName) {
139 92 : NameTable.insert(std::make_pair(FName, 0));
140 46 : }
141 :
142 30 : void SampleProfileWriterBinary::addNames(const FunctionSamples &S) {
143 : // Add all the names in indirect call targets.
144 96 : for (const auto &I : S.getBodySamples()) {
145 : const SampleRecord &Sample = I.second;
146 148 : for (const auto &J : Sample.getCallTargets())
147 16 : addName(J.first());
148 : }
149 :
150 : // Recursively add all the names for inlined callsites.
151 36 : for (const auto &J : S.getCallsiteSamples())
152 14 : for (const auto &FS : J.second) {
153 8 : const FunctionSamples &CalleeSamples = FS.second;
154 8 : addName(CalleeSamples.getName());
155 8 : addNames(CalleeSamples);
156 : }
157 30 : }
158 :
159 9 : void SampleProfileWriterBinary::stablizeNameTable(std::set<StringRef> &V) {
160 : // Sort the names to make NameTable deterministic.
161 43 : for (const auto &I : NameTable)
162 34 : V.insert(I.first);
163 : int i = 0;
164 43 : for (const StringRef &N : V)
165 34 : NameTable[N] = i++;
166 9 : }
167 :
168 8 : std::error_code SampleProfileWriterRawBinary::writeNameTable() {
169 : auto &OS = *OutputStream;
170 : std::set<StringRef> V;
171 8 : stablizeNameTable(V);
172 :
173 : // Write out the name table.
174 8 : encodeULEB128(NameTable.size(), OS);
175 38 : for (auto N : V) {
176 30 : OS << N;
177 30 : encodeULEB128(0, OS);
178 : }
179 8 : return sampleprof_error::success;
180 : }
181 :
182 1 : std::error_code SampleProfileWriterCompactBinary::writeFuncOffsetTable() {
183 : auto &OS = *OutputStream;
184 :
185 : // Fill the slot remembered by TableOffset with the offset of FuncOffsetTable.
186 : auto &OFS = static_cast<raw_fd_ostream &>(OS);
187 : uint64_t FuncOffsetTableStart = OS.tell();
188 1 : if (OFS.seek(TableOffset) == (uint64_t)-1)
189 0 : return sampleprof_error::ostream_seek_unsupported;
190 : support::endian::Writer Writer(*OutputStream, support::little);
191 : Writer.write(FuncOffsetTableStart);
192 1 : if (OFS.seek(FuncOffsetTableStart) == (uint64_t)-1)
193 0 : return sampleprof_error::ostream_seek_unsupported;
194 :
195 : // Write out the table size.
196 1 : encodeULEB128(FuncOffsetTable.size(), OS);
197 :
198 : // Write out FuncOffsetTable.
199 3 : for (auto entry : FuncOffsetTable) {
200 2 : writeNameIdx(entry.first);
201 2 : encodeULEB128(entry.second, OS);
202 : }
203 1 : return sampleprof_error::success;
204 : }
205 :
206 1 : std::error_code SampleProfileWriterCompactBinary::writeNameTable() {
207 : auto &OS = *OutputStream;
208 : std::set<StringRef> V;
209 1 : stablizeNameTable(V);
210 :
211 : // Write out the name table.
212 1 : encodeULEB128(NameTable.size(), OS);
213 5 : for (auto N : V) {
214 4 : encodeULEB128(MD5Hash(N), OS);
215 : }
216 1 : return sampleprof_error::success;
217 : }
218 :
219 8 : std::error_code SampleProfileWriterRawBinary::writeMagicIdent() {
220 : auto &OS = *OutputStream;
221 : // Write file magic identifier.
222 8 : encodeULEB128(SPMagic(), OS);
223 8 : encodeULEB128(SPVersion(), OS);
224 8 : return sampleprof_error::success;
225 : }
226 :
227 1 : std::error_code SampleProfileWriterCompactBinary::writeMagicIdent() {
228 : auto &OS = *OutputStream;
229 : // Write file magic identifier.
230 1 : encodeULEB128(SPMagic(SPF_Compact_Binary), OS);
231 1 : encodeULEB128(SPVersion(), OS);
232 1 : return sampleprof_error::success;
233 : }
234 :
235 9 : std::error_code SampleProfileWriterBinary::writeHeader(
236 : const StringMap<FunctionSamples> &ProfileMap) {
237 9 : writeMagicIdent();
238 :
239 9 : computeSummary(ProfileMap);
240 9 : if (auto EC = writeSummary())
241 0 : return EC;
242 :
243 : // Generate the name table for all the functions referenced in the profile.
244 40 : for (const auto &I : ProfileMap) {
245 22 : addName(I.first());
246 22 : addNames(I.second);
247 : }
248 :
249 9 : writeNameTable();
250 9 : return sampleprof_error::success;
251 : }
252 :
253 1 : std::error_code SampleProfileWriterCompactBinary::writeHeader(
254 : const StringMap<FunctionSamples> &ProfileMap) {
255 : support::endian::Writer Writer(*OutputStream, support::little);
256 1 : if (auto EC = SampleProfileWriterBinary::writeHeader(ProfileMap))
257 0 : return EC;
258 :
259 : // Reserve a slot for the offset of function offset table. The slot will
260 : // be populated with the offset of FuncOffsetTable later.
261 1 : TableOffset = OutputStream->tell();
262 : Writer.write(static_cast<uint64_t>(-2));
263 1 : return sampleprof_error::success;
264 : }
265 :
266 9 : std::error_code SampleProfileWriterBinary::writeSummary() {
267 : auto &OS = *OutputStream;
268 9 : encodeULEB128(Summary->getTotalCount(), OS);
269 9 : encodeULEB128(Summary->getMaxCount(), OS);
270 9 : encodeULEB128(Summary->getMaxFunctionCount(), OS);
271 9 : encodeULEB128(Summary->getNumCounts(), OS);
272 9 : encodeULEB128(Summary->getNumFunctions(), OS);
273 : std::vector<ProfileSummaryEntry> &Entries = Summary->getDetailedSummary();
274 18 : encodeULEB128(Entries.size(), OS);
275 153 : for (auto Entry : Entries) {
276 144 : encodeULEB128(Entry.Cutoff, OS);
277 144 : encodeULEB128(Entry.MinCount, OS);
278 144 : encodeULEB128(Entry.NumCounts, OS);
279 : }
280 9 : return sampleprof_error::success;
281 : }
282 30 : std::error_code SampleProfileWriterBinary::writeBody(const FunctionSamples &S) {
283 : auto &OS = *OutputStream;
284 :
285 30 : if (std::error_code EC = writeNameIdx(S.getName()))
286 0 : return EC;
287 :
288 30 : encodeULEB128(S.getTotalSamples(), OS);
289 :
290 : // Emit all the body samples.
291 30 : encodeULEB128(S.getBodySamples().size(), OS);
292 96 : for (const auto &I : S.getBodySamples()) {
293 66 : LineLocation Loc = I.first;
294 : const SampleRecord &Sample = I.second;
295 66 : encodeULEB128(Loc.LineOffset, OS);
296 66 : encodeULEB128(Loc.Discriminator, OS);
297 66 : encodeULEB128(Sample.getSamples(), OS);
298 66 : encodeULEB128(Sample.getCallTargets().size(), OS);
299 148 : for (const auto &J : Sample.getCallTargets()) {
300 16 : StringRef Callee = J.first();
301 16 : uint64_t CalleeSamples = J.second;
302 16 : if (std::error_code EC = writeNameIdx(Callee))
303 0 : return EC;
304 16 : encodeULEB128(CalleeSamples, OS);
305 : }
306 : }
307 :
308 : // Recursively emit all the callsite samples.
309 : uint64_t NumCallsites = 0;
310 36 : for (const auto &J : S.getCallsiteSamples())
311 6 : NumCallsites += J.second.size();
312 30 : encodeULEB128(NumCallsites, OS);
313 36 : for (const auto &J : S.getCallsiteSamples())
314 14 : for (const auto &FS : J.second) {
315 8 : LineLocation Loc = J.first;
316 8 : const FunctionSamples &CalleeSamples = FS.second;
317 8 : encodeULEB128(Loc.LineOffset, OS);
318 8 : encodeULEB128(Loc.Discriminator, OS);
319 8 : if (std::error_code EC = writeBody(CalleeSamples))
320 0 : return EC;
321 : }
322 :
323 30 : return sampleprof_error::success;
324 : }
325 :
326 : /// Write samples of a top-level function to a binary file.
327 : ///
328 : /// \returns true if the samples were written successfully, false otherwise.
329 20 : std::error_code SampleProfileWriterBinary::write(const FunctionSamples &S) {
330 20 : encodeULEB128(S.getHeadSamples(), *OutputStream);
331 20 : return writeBody(S);
332 : }
333 :
334 : std::error_code
335 2 : SampleProfileWriterCompactBinary::write(const FunctionSamples &S) {
336 : uint64_t Offset = OutputStream->tell();
337 2 : StringRef Name = S.getName();
338 2 : FuncOffsetTable[Name] = Offset;
339 2 : encodeULEB128(S.getHeadSamples(), *OutputStream);
340 2 : return writeBody(S);
341 : }
342 :
343 : /// Create a sample profile file writer based on the specified format.
344 : ///
345 : /// \param Filename The file to create.
346 : ///
347 : /// \param Format Encoding format for the profile file.
348 : ///
349 : /// \returns an error code indicating the status of the created writer.
350 : ErrorOr<std::unique_ptr<SampleProfileWriter>>
351 17 : SampleProfileWriter::create(StringRef Filename, SampleProfileFormat Format) {
352 : std::error_code EC;
353 17 : std::unique_ptr<raw_ostream> OS;
354 17 : if (Format == SPF_Binary || Format == SPF_Compact_Binary)
355 12 : OS.reset(new raw_fd_ostream(Filename, EC, sys::fs::F_None));
356 : else
357 22 : OS.reset(new raw_fd_ostream(Filename, EC, sys::fs::F_Text));
358 17 : if (EC)
359 0 : return EC;
360 :
361 17 : return create(OS, Format);
362 : }
363 :
364 : /// Create a sample profile stream writer based on the specified format.
365 : ///
366 : /// \param OS The output stream to store the profile data to.
367 : ///
368 : /// \param Format Encoding format for the profile file.
369 : ///
370 : /// \returns an error code indicating the status of the created writer.
371 : ErrorOr<std::unique_ptr<SampleProfileWriter>>
372 22 : SampleProfileWriter::create(std::unique_ptr<raw_ostream> &OS,
373 : SampleProfileFormat Format) {
374 : std::error_code EC;
375 : std::unique_ptr<SampleProfileWriter> Writer;
376 :
377 22 : if (Format == SPF_Binary)
378 8 : Writer.reset(new SampleProfileWriterRawBinary(OS));
379 14 : else if (Format == SPF_Compact_Binary)
380 1 : Writer.reset(new SampleProfileWriterCompactBinary(OS));
381 13 : else if (Format == SPF_Text)
382 13 : Writer.reset(new SampleProfileWriterText(OS));
383 0 : else if (Format == SPF_GCC)
384 : EC = sampleprof_error::unsupported_writing_format;
385 : else
386 : EC = sampleprof_error::unrecognized_format;
387 :
388 22 : if (EC)
389 0 : return EC;
390 :
391 : return std::move(Writer);
392 : }
393 :
394 9 : void SampleProfileWriter::computeSummary(
395 : const StringMap<FunctionSamples> &ProfileMap) {
396 9 : SampleProfileSummaryBuilder Builder(ProfileSummaryBuilder::DefaultCutoffs);
397 40 : for (const auto &I : ProfileMap) {
398 22 : const FunctionSamples &Profile = I.second;
399 22 : Builder.addRecord(Profile);
400 : }
401 18 : Summary = Builder.getSummary();
402 9 : }
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