1__extension__ typedef unsigned long long int uint64_t;
2typedef uint64_t ScmUInt64;
3void swapb64(ScmUInt64 *loc)
4{
5    union {
6        ScmUInt64 l;
7        unsigned char c[4];
8    } dd;
9    unsigned char t;
10    dd.l = *loc;
11    (t = dd.c[3], dd.c[3] = dd.c[4], dd.c[4] = t);
12}
13