bench/bench_reverse.cpp

#include <iostream>
#include <Eigen/Core>
#include <bench/BenchUtil.h>
using namespace Eigen;

#ifndef REPEAT
#define REPEAT 100000
#endif

#ifndef TRIES
#define TRIES 20
#endif

typedef double Scalar;

template <typename MatrixType>
__attribute__((noinline)) void bench_reverse(const MatrixType& m) {
  int rows = m.rows();
  int cols = m.cols();
  int size = m.size();

  int repeats = (REPEAT * 1000) / size;
  MatrixType a = MatrixType::Random(rows, cols);
  MatrixType b = MatrixType::Random(rows, cols);

  BenchTimer timerB, timerH, timerV;

  Scalar acc = 0;
  int r = internal::random<int>(0, rows - 1);
  int c = internal::random<int>(0, cols - 1);
  for (int t = 0; t < TRIES; ++t) {
    timerB.start();
    for (int k = 0; k < repeats; ++k) {
      asm("#begin foo");
      b = a.reverse();
      asm("#end foo");
      acc += b.coeff(r, c);
    }
    timerB.stop();
  }

  if (MatrixType::RowsAtCompileTime == Dynamic)
    std::cout << "dyn   ";
  else
    std::cout << "fixed ";
  std::cout << rows << " x " << cols << " \t" << (timerB.value() * REPEAT) / repeats << "s "
            << "(" << 1e-6 * size * repeats / timerB.value() << " MFLOPS)\t";

  std::cout << "\n";
  // make sure the compiler does not optimize too much
  if (acc == 123) std::cout << acc;
}

int main(int argc, char* argv[]) {
  const int dynsizes[] = {4, 6, 8, 16, 24, 32, 49, 64, 128, 256, 512, 900, 0};
  std::cout << "size            no sqrt                           standard";
  //   #ifdef BENCH_GSL
  //   std::cout << "       GSL (standard + double + ATLAS)  ";
  //   #endif
  std::cout << "\n";
  for (uint i = 0; dynsizes[i] > 0; ++i) {
    bench_reverse(Matrix<Scalar, Dynamic, Dynamic>(dynsizes[i], dynsizes[i]));
    bench_reverse(Matrix<Scalar, Dynamic, 1>(dynsizes[i] * dynsizes[i]));
  }
  //   bench_reverse(Matrix<Scalar,2,2>());
  //   bench_reverse(Matrix<Scalar,3,3>());
  //   bench_reverse(Matrix<Scalar,4,4>());
  //   bench_reverse(Matrix<Scalar,5,5>());
  //   bench_reverse(Matrix<Scalar,6,6>());
  //   bench_reverse(Matrix<Scalar,7,7>());
  //   bench_reverse(Matrix<Scalar,8,8>());
  //   bench_reverse(Matrix<Scalar,12,12>());
  //   bench_reverse(Matrix<Scalar,16,16>());
  return 0;
}