ra-ra/bench/bench-pack.cc

// -*- mode: c++; coding: utf-8 -*-
// ra-ra/bench - pack() operator vs explode/collapse.

// (c) Daniel Llorens - 2016-2017
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the Free
// Software Foundation; either version 3 of the License, or (at your option) any
// later version.

#include <iostream>
#include <iomanip>
#include "ra/bench.hh"

using std::cout, std::endl, std::flush, ra::TestRecorder;
using real = double;
using complex = std::complex<double>;

int main()
{
    TestRecorder tr(cout);
    cout.precision(4);

    auto bench = [&tr](auto && f, auto A_, char const * tag, int size, int reps)
        {
            using A = decltype(A_);
            A a({size}, ra::none);

            Benchmark bm { reps, 3 };
            auto bv = bm.run([&]() { f(a, size); });
            tr.info(std::setw(5), std::fixed, bm.avg(bv)/size/1e-9, " ns [", bm.stddev(bv)/size/1e-9 ,"] ", tag)
                .test_eq(ra::pack<complex>(ra::iota(size, 0.), size-ra::iota(size, 0.)), a);
        };

    auto f_raw = [](auto & a, int size)
        {
            real * p = reinterpret_cast<real *>(a.data());
            for (ra::dim_t i=0; i!=size; ++i, p+=2) {
                p[0] = i;
                p[1] = size-i;
            }
        };
    auto f_reim = [](auto & a, int size)
        {
            real_part(a) = ra::iota(size);
            imag_part(a) = size-ra::iota(size);
        };
    auto f_collapse = [](auto & a, int size)
        {
            auto areim = ra::collapse<real>(a);
            areim(ra::all, 0) = ra::iota(size);
            areim(ra::all, 1) = size-ra::iota(size);
        };
    auto f_pack = [](auto & a, int size)
        {
            a = ra::pack<complex>(ra::iota(size, 0.), size-ra::iota(size, 0.));
        };
    auto f_xI = [](auto & a, int size)
        {
            a = ra::iota(size, 0.) + xI(size-ra::iota(size, 0.));
        };

    auto bench_all = [&](auto A_, int size, int n)
        {
            tr.section("size ", size, ", n ", n);
            bench(f_raw, A_, "raw", size, n);
            bench(f_reim, A_, "re/im", size, n);
            bench(f_collapse, A_, "collapse", size, n);
            bench(f_pack, A_, "pack", size, n);
            bench(f_xI, A_, "xI", size, n);
        };

    bench_all(ra::Big<complex, 1>(), 10, 1000000);
    bench_all(ra::Big<complex, 1>(), 100, 100000);
    bench_all(ra::Big<complex, 1>(), 1000, 10000);
    bench_all(ra::Big<complex, 1>(), 10000, 1000);
    bench_all(ra::Big<complex, 1>(), 100000, 100);
    bench_all(ra::Big<complex, 1>(), 1000000, 10);

    return tr.summary();
}