bsdnt exp(1) benchmark program

gistfile1.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include "nn.h"
#include "test.h"
#include "zz.h"

void
zz_bsplit(zz_t p, zz_t q, ulong a, ulong b)
{
    if (b - a == 1)
    {
        zz_seti(p, 1);
        zz_seti(q, b);
    }
    else
    {
        ulong m;

        zz_t p1, q2;

        zz_init(p1);
        zz_init(q2);

        m = a + (b - a) / 2;

        zz_bsplit(p1, q, a, m);
        zz_bsplit(p, q2, m, b);

        zz_mul(p1, p1, q2);
        zz_add(p, p, p1);

        zz_mul(q, q, q2);

        zz_clear(p1);
        zz_clear(q2);
    }
}

void zz_e(zz_t y, ulong prec)
{
    ulong N;
    zz_t p, q;

    N = 1.1 * prec / log(prec) + 20;

    zz_init(p);
    zz_init(q);

    zz_bsplit(p, q, 0, N);

    zz_add(p, p, q);
    zz_mul_2exp(p, p, prec);
    zz_div(y, p, q);

    zz_clear(p);
    zz_clear(q);
}

void time_e(void)
{
    ulong digits, prec, count, iter;
    clock_t t;

    zz_t y;
    zz_init(y);

    zz_e(y, 333);
    zz_print(y);

    printf("\n");

    for (digits = 100; digits <= 10000000; digits *= 10)
    {
        prec = digits * 3.333;

        printf("digits = %lu: ", digits);
        fflush(stdout);

        iter = 1;
        if (digits == 100) iter = 100000;
        if (digits == 1000) iter = 10000;
        if (digits == 10000) iter = 100;
        if (digits == 100000) iter = 10;
        if (digits == 1000000) iter = 1;

        t = clock();
        for (count = 0; count < iter; count++)
            zz_e(y, prec);
        t = clock() - t;

        printf("%g s\n", ((double) t) / CLOCKS_PER_SEC / iter);

    }

    zz_clear(y);
}

int main(void)
{
   time_e();
   return 0;
}