Quick test for timing behavior of cos C function

cos_test.c

/* Program to demonstrate time taken by function cos() */
#include <stdio.h>
#include <time.h>
#include <math.h>

// The main program calls fun() and measures time taken by fun()
int main()
{
    // Calculate the time taken by fun()
    clock_t start;
    clock_t end;
    clock_t used;
    clock_t min_time;
    clock_t max_time;
    double max_value;
    double min_value;
    const double start_value = -100.0;
    const double end_value = 100.0;
    const double step = 0.00001;
    double value;

    min_time = 1000000;
    max_time = 0;
    value = start_value;

    while (value < end_value) {
        start = clock();
        cos(value);
        end = clock();
        used = end - start;
        if (used < min_time) {
            min_time = used;
            min_value = value;
        }
        if (used > max_time) {
            max_time = used;
            max_value = value;
        }
        value += step;
    }

    printf("min: %u value: %f \n", min_time, min_value);
    printf("max: %u value: %f \n", max_time, max_value);
    return 0;
}

I haven't had a chance to think about what we're actually trying to measure here, but there's a problem with printing clock_t values with the format specifier "%u".

Maybe add

include <inttypes.h>

Then cast the min_time and max_time so printf can handle them.

printf("min: %ju value: %f \n", (uintmax_t) min_time, min_value);
printf("max: %ju value: %f \n", (uintmax_t) max_time, max_value);