benchmarks/fft.cpp

/*******************************************************
 * Copyright (c) 2014, ArrayFire
 * All rights reserved.
 *
 * This file is distributed under 3-clause BSD license.
 * The complete license agreement can be obtained at:
 * http://arrayfire.com/licenses/BSD-3-Clause
 ********************************************************/
 
#include <arrayfire.h>
#include <math.h>
#include <stdio.h>
#include <cstdlib>
 
using namespace af;
 
// create a small wrapper to benchmark
static array A;  // populated before each timing
static void fn() {
    array B = fft2(A);  // 2d fft
    B.eval();           // ensure evaluated
}
 
int main(int argc, char** argv) {
    try {
        int device = argc > 1 ? atoi(argv[1]) : 0;
        setDevice(device);
        info();
 
        printf("Benchmark N-by-N 2D fft\n");
        for (int M = 7; M <= 12; M++) {
            int N = (1 << M);
 
            printf("%4d x %4d: ", N, N);
            A             = randu(N, N);
            double time   = timeit(fn);  // time in seconds
            double gflops = 10.0 * N * N * M / (time * 1e9);
 
            printf(" %4.0f Gflops\n", gflops);
            fflush(stdout);
        }
    } catch (af::exception& e) { fprintf(stderr, "%s\n", e.what()); }
 
    return 0;
}