Benchmark Codes

Various Benchmark Files

I prefer to run with:

./bin/Benchmark --benchmark_repetitions=10 --benchmark_report_aggregates_only=true

Note: The headers typically are something like:

#include <benchmark/benchmark.h>
#include <string>
#include <vector>

#include "DataStructures/DataBox/DataBoxTag.hpp"
#include "DataStructures/DataVector.hpp"
#include "DataStructures/Tensor/Tensor.hpp"
#include "DataStructures/Variables.hpp"
#include "Domain/CoordinateMaps/Affine.hpp"
#include "Domain/CoordinateMaps/CoordinateMap.hpp"
#include "Domain/CoordinateMaps/ProductMaps.hpp"
#include "Domain/Element.hpp"
#include "Domain/LogicalCoordinates.hpp"
#include "Domain/Mesh.hpp"
#include "NumericalAlgorithms/LinearOperators/DefiniteIntegral.cpp"
#include "NumericalAlgorithms/LinearOperators/PartialDerivatives.hpp"
#include "NumericalAlgorithms/Spectral/Spectral.hpp"
#include "PointwiseFunctions/MathFunctions/PowX.hpp"

// Charm looks for this function but since we build without a main function or
// main module we just have it be empty
extern "C" void CkRegisterMainModule(void) {}

Note: Using a DenseRange to iterate over different mesh sizes is very useful. This is done, e.g.

BENCHMARK(bench_2d)->DenseRange(2, 12, 1);

which will iterate from [2, ..., 12] with a stride of 1.

Definite Integral

namespace {
// clang-tidy: don't pass be non-const reference
void bench_3d(benchmark::State& state) {  // NOLINT
  const size_t pts_1d = state.range(0);
  constexpr const size_t Dim = 3;
  const Mesh<Dim> mesh{pts_1d, Spectral::Basis::Legendre,
                       Spectral::Quadrature::GaussLobatto};

  DataVector a(mesh.number_of_grid_points(), 0.0);

  for (auto _ : state) {
    benchmark::DoNotOptimize(definite_integral(a, mesh));
  }
}
BENCHMARK(bench_3d)->DenseRange(2, 12, 1);

void bench_2d(benchmark::State& state) {  // NOLINT
  const size_t pts_1d = state.range(0);
  constexpr const size_t Dim = 2;
  const Mesh<Dim> mesh{pts_1d, Spectral::Basis::Legendre,
                       Spectral::Quadrature::GaussLobatto};

  DataVector a(mesh.number_of_grid_points(), 0.0);

  for (auto _ : state) {
    benchmark::DoNotOptimize(definite_integral(a, mesh));
  }
}
BENCHMARK(bench_2d)->DenseRange(2, 12, 1);
}  // namespace

BENCHMARK_MAIN();