SWAP
#define SWAP(x,y) {t = (x); (x) = (y); (y) = t;}
#define SWAP(a, b, count, size, tmp) { \
# define SWAP(n) \
# define SWAP(n) (n)
# define SWAP(n) \
# define SWAP(n) (n)
#define SWAP(x) (_lrotl(x, 8) & 0x00ff00ff | _lrotr(x, 8) & 0xff00ff00)
#define SWAP(type, a1, a2) \
#define SWAP(a, b) { typeof(a) c = a; a = b; b = c; }