double => long cast

gistfile1.txt

#include <stdio.h>

int main(void) {
    double  d  = 1234567890;
    double *dp = &d;
    long  l  = (double) d;
    long *lp = (long *) dp;
    union dl_t {
        double d;
        long l;
    } dl;
    dl.d = d;
    printf("d:%f dp:%f\n", d, *dp);
    printf("l:%ld lp:%ld dl.l=%ld\n", l, *lp, dl.l);
    return 0;
}

/* outout
d:1234567890.000000 dp:1234567890.000000
l:1234567890 lp:4742964961033060352 dl.l=4742964961033060352
*/