About func in md5.c

Hi, All maybe i totally dont figure this right, in the func void byteReverse(unsigned char *buf, unsigned longs) { u32 t; do { t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 | ((unsigned) buf[1] << 8 | buf[0]); *(u32 *) buf = t; buf += 4; } while (--longs); } isnt that buf[3] should shift 24?