output

root@debian-mipsel:~/MoarVM# ./test_double 
2141029028

test_double.c

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

struct MVMP6numBody {
    /* Float storage slot. */
    union {
        double n64;
        float  n32;
    } value;
};
typedef struct MVMP6numBody MVMP6numBody;

int main(int argc, char **argv) {
    MVMP6numBody body;
    body.value.n64 = 42.1;
    printf("%d\n", body.value.n64);
    return EXIT_SUCCESS;
}