#include <stdio.h>
#include <stdlib.h>
#include <fenv.h>

double n[] = { 0.000005, 0.000015, 0.000025, 0.000035, 0.000045, 0.000055, 0.000065 };
char *str[] = { "0.000005", "0.000015", "0.000025", "0.000035", "0.000045", "0.000055", "0.000065" };

int main(int argc, char *argv[]) {
    int i, j;
    for (j = 0; j < 4; j++) {
        fesetround(j);
        printf("rounding: %d\n", j);
        double m = n[0];
        for (i = 0; i < sizeof(n)/sizeof(*n); i++) {
            printf("  compiler: %40.30a => %40.30f\n", n[i], n[i]);
            printf("  atof:     %40.30a => %40.30f\n", atof(str[i]), atof(str[i]));
            printf("  calc:     %40.30a => %40.30f\n", m, m);
            m += 0.00001;
        }
    }
    return 0;
}