libc/benchmarks/LibcMemoryBenchmarkMain.cpp

   1 //===-- Benchmark ---------------------------------------------------------===//
   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 #include "JSON.h"
  10 #include "LibcBenchmark.h"
  11 #include "LibcMemoryBenchmark.h"
  12 #include "MemorySizeDistributions.h"
  13 #include "llvm/Support/CommandLine.h"
  14 #include "llvm/Support/ErrorHandling.h"
  15 #include "llvm/Support/FileSystem.h"
  16 #include "llvm/Support/JSON.h"
  17 #include "llvm/Support/MathExtras.h"
  18 #include "llvm/Support/MemoryBuffer.h"
  19 #include "llvm/Support/raw_ostream.h"
  20
  21 #include <cstring>
  22 #include <unistd.h>
  23
  24 namespace __llvm_libc {
  25
  26 extern void *memcpy(void *__restrict, const void *__restrict, size_t);
  27 extern void *memmove(void *, const void *, size_t);
  28 extern void *memset(void *, int, size_t);
  29 extern void bzero(void *, size_t);
  30 extern int memcmp(const void *, const void *, size_t);
  31 extern int bcmp(const void *, const void *, size_t);
  32
  33 } // namespace __llvm_libc
  34
  35 namespace llvm {
  36 namespace libc_benchmarks {
  37
  38 static cl::opt<std::string>
  39     StudyName("study-name", cl::desc("The name for this study"), cl::Required);
  40
  41 static cl::opt<std::string>
  42     SizeDistributionName("size-distribution-name",
  43                          cl::desc("The name of the distribution to use"));
  44
  45 static cl::opt<bool>
  46     SweepMode("sweep-mode",
  47               cl::desc("If set, benchmark all sizes from 0 to sweep-max-size"));
  48
  49 static cl::opt<uint32_t>
  50     SweepMaxSize("sweep-max-size",
  51                  cl::desc("The maximum size to use in sweep-mode"),
  52                  cl::init(256));
  53
  54 static cl::opt<uint32_t>
  55     AlignedAccess("aligned-access",
  56                   cl::desc("The alignment to use when accessing the buffers\n"
  57                            "Default is unaligned\n"
  58                            "Use 0 to disable address randomization"),
  59                   cl::init(1));
  60
  61 static cl::opt<std::string> Output("output",
  62                                    cl::desc("Specify output filename"),
  63                                    cl::value_desc("filename"), cl::init("-"));
  64
  65 static cl::opt<uint32_t>
  66     NumTrials("num-trials", cl::desc("The number of benchmarks run to perform"),
  67               cl::init(1));
  68
  69 #if defined(LIBC_BENCHMARK_FUNCTION_MEMCPY)
  70 #define LIBC_BENCHMARK_FUNCTION LIBC_BENCHMARK_FUNCTION_MEMCPY
  71 using BenchmarkSetup = CopySetup;
  72 #elif defined(LIBC_BENCHMARK_FUNCTION_MEMMOVE)
  73 #define LIBC_BENCHMARK_FUNCTION LIBC_BENCHMARK_FUNCTION_MEMMOVE
  74 using BenchmarkSetup = MoveSetup;
  75 #elif defined(LIBC_BENCHMARK_FUNCTION_MEMSET)
  76 #define LIBC_BENCHMARK_FUNCTION LIBC_BENCHMARK_FUNCTION_MEMSET
  77 using BenchmarkSetup = SetSetup;
  78 #elif defined(LIBC_BENCHMARK_FUNCTION_BZERO)
  79 #define LIBC_BENCHMARK_FUNCTION LIBC_BENCHMARK_FUNCTION_BZERO
  80 using BenchmarkSetup = SetSetup;
  81 #elif defined(LIBC_BENCHMARK_FUNCTION_MEMCMP)
  82 #define LIBC_BENCHMARK_FUNCTION LIBC_BENCHMARK_FUNCTION_MEMCMP
  83 using BenchmarkSetup = ComparisonSetup;
  84 #elif defined(LIBC_BENCHMARK_FUNCTION_BCMP)
  85 #define LIBC_BENCHMARK_FUNCTION LIBC_BENCHMARK_FUNCTION_BCMP
  86 using BenchmarkSetup = ComparisonSetup;
  87 #else
  88 #error "Missing LIBC_BENCHMARK_FUNCTION_XXX definition"
  89 #endif
  90
  91 struct MemfunctionBenchmarkBase : public BenchmarkSetup {
  92   MemfunctionBenchmarkBase() : ReportProgress(isatty(fileno(stdout))) {}
  93   virtual ~MemfunctionBenchmarkBase() {}
  94
  95   virtual Study run() = 0;
  96
  97   CircularArrayRef<ParameterBatch::ParameterType>
  98   generateBatch(size_t Iterations) {
  99     randomize();
 100     return cycle(ArrayRef(Parameters), Iterations);
 101   }
 102
 103 protected:
 104   Study createStudy() {
 105     Study Study;
 106     // Setup study.
 107     Study.StudyName = StudyName;
 108     Runtime &RI = Study.Runtime;
 109     RI.Host = HostState::get();
 110     RI.BufferSize = BufferSize;
 111     RI.BatchParameterCount = BatchSize;
 112
 113     BenchmarkOptions &BO = RI.BenchmarkOptions;
 114     BO.MinDuration = std::chrono::milliseconds(1);
 115     BO.MaxDuration = std::chrono::seconds(1);
 116     BO.MaxIterations = 10'000'000U;
 117     BO.MinSamples = 4;
 118     BO.MaxSamples = 1000;
 119     BO.Epsilon = 0.01; // 1%
 120     BO.ScalingFactor = 1.4;
 121
 122     StudyConfiguration &SC = Study.Configuration;
 123     SC.NumTrials = NumTrials;
 124     SC.IsSweepMode = SweepMode;
 125     SC.AccessAlignment = MaybeAlign(AlignedAccess);
 126     SC.Function = LIBC_BENCHMARK_FUNCTION_NAME;
 127     return Study;
 128   }
 129
 130   void runTrials(const BenchmarkOptions &Options,
 131                  std::vector<Duration> &Measurements) {
 132     for (size_t i = 0; i < NumTrials; ++i) {
 133       const BenchmarkResult Result = benchmark(
 134           Options, *this, [this](ParameterBatch::ParameterType Parameter) {
 135             return Call(Parameter, LIBC_BENCHMARK_FUNCTION);
 136           });
 137       Measurements.push_back(Result.BestGuess);
 138       reportProgress(Measurements);
 139     }
 140   }
 141
 142   virtual void randomize() = 0;
 143
 144 private:
 145   bool ReportProgress;
 146
 147   void reportProgress(const std::vector<Duration> &Measurements) {
 148     if (!ReportProgress)
 149       return;
 150     static size_t LastPercent = -1;
 151     const size_t TotalSteps = Measurements.capacity();
 152     const size_t Steps = Measurements.size();
 153     const size_t Percent = 100 * Steps / TotalSteps;
 154     if (Percent == LastPercent)
 155       return;
 156     LastPercent = Percent;
 157     size_t I = 0;
 158     errs() << '[';
 159     for (; I <= Percent; ++I)
 160       errs() << '#';
 161     for (; I <= 100; ++I)
 162       errs() << '_';
 163     errs() << "] " << Percent << '%' << '\r';
 164   }
 165 };
 166
 167 struct MemfunctionBenchmarkSweep final : public MemfunctionBenchmarkBase {
 168   MemfunctionBenchmarkSweep()
 169       : OffsetSampler(MemfunctionBenchmarkBase::BufferSize, SweepMaxSize,
 170                       MaybeAlign(AlignedAccess)) {}
 171
 172   virtual void randomize() override {
 173     for (auto &P : Parameters) {
 174       P.OffsetBytes = OffsetSampler(Gen);
 175       P.SizeBytes = CurrentSweepSize;
 176       checkValid(P);
 177     }
 178   }
 179
 180   virtual Study run() override {
 181     Study Study = createStudy();
 182     Study.Configuration.SweepModeMaxSize = SweepMaxSize;
 183     BenchmarkOptions &BO = Study.Runtime.BenchmarkOptions;
 184     BO.MinDuration = std::chrono::milliseconds(1);
 185     BO.InitialIterations = 100;
 186     auto &Measurements = Study.Measurements;
 187     Measurements.reserve(NumTrials * SweepMaxSize);
 188     for (size_t Size = 0; Size <= SweepMaxSize; ++Size) {
 189       CurrentSweepSize = Size;
 190       runTrials(BO, Measurements);
 191     }
 192     return Study;
 193   }
 194
 195 private:
 196   size_t CurrentSweepSize = 0;
 197   OffsetDistribution OffsetSampler;
 198   std::mt19937_64 Gen;
 199 };
 200
 201 struct MemfunctionBenchmarkDistribution final
 202     : public MemfunctionBenchmarkBase {
 203   MemfunctionBenchmarkDistribution(MemorySizeDistribution Distribution)
 204       : Distribution(Distribution), Probabilities(Distribution.Probabilities),
 205         SizeSampler(Probabilities.begin(), Probabilities.end()),
 206         OffsetSampler(MemfunctionBenchmarkBase::BufferSize,
 207                       Probabilities.size() - 1, MaybeAlign(AlignedAccess)) {}
 208
 209   virtual void randomize() override {
 210     for (auto &P : Parameters) {
 211       P.OffsetBytes = OffsetSampler(Gen);
 212       P.SizeBytes = SizeSampler(Gen);
 213       checkValid(P);
 214     }
 215   }
 216
 217   virtual Study run() override {
 218     Study Study = createStudy();
 219     Study.Configuration.SizeDistributionName = Distribution.Name.str();
 220     BenchmarkOptions &BO = Study.Runtime.BenchmarkOptions;
 221     BO.MinDuration = std::chrono::milliseconds(10);
 222     BO.InitialIterations = BatchSize * 10;
 223     auto &Measurements = Study.Measurements;
 224     Measurements.reserve(NumTrials);
 225     runTrials(BO, Measurements);
 226     return Study;
 227   }
 228
 229 private:
 230   MemorySizeDistribution Distribution;
 231   ArrayRef<double> Probabilities;
 232   std::discrete_distribution<unsigned> SizeSampler;
 233   OffsetDistribution OffsetSampler;
 234   std::mt19937_64 Gen;
 235 };
 236
 237 void writeStudy(const Study &S) {
 238   std::error_code EC;
 239   raw_fd_ostream FOS(Output, EC);
 240   if (EC)
 241     report_fatal_error(Twine("Could not open file: ")
 242                            .concat(EC.message())
 243                            .concat(", ")
 244                            .concat(Output));
 245   json::OStream JOS(FOS);
 246   serializeToJson(S, JOS);
 247   FOS << "\n";
 248 }
 249
 250 void main() {
 251   checkRequirements();
 252   if (!isPowerOf2_32(AlignedAccess))
 253     report_fatal_error(AlignedAccess.ArgStr +
 254                        Twine(" must be a power of two or zero"));
 255
 256   const bool HasDistributionName = !SizeDistributionName.empty();
 257   if (SweepMode && HasDistributionName)
 258     report_fatal_error("Select only one of `--" + Twine(SweepMode.ArgStr) +
 259                        "` or `--" + Twine(SizeDistributionName.ArgStr) + "`");
 260
 261   std::unique_ptr<MemfunctionBenchmarkBase> Benchmark;
 262   if (SweepMode)
 263     Benchmark.reset(new MemfunctionBenchmarkSweep());
 264   else
 265     Benchmark.reset(new MemfunctionBenchmarkDistribution(getDistributionOrDie(
 266         BenchmarkSetup::getDistributions(), SizeDistributionName)));
 267   writeStudy(Benchmark->run());
 268 }
 269
 270 } // namespace libc_benchmarks
 271 } // namespace llvm
 272
 273 #ifndef NDEBUG
 274 #error For reproducibility benchmarks should not be compiled in DEBUG mode.
 275 #endif
 276
 277 int main(int argc, char **argv) {
 278   llvm::cl::ParseCommandLineOptions(argc, argv);
 279   llvm::libc_benchmarks::main();
 280   return EXIT_SUCCESS;
 281 }