1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Jeffrey Mogul. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the University of California, Berkeley. The name of the 14 * University may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 */ 20 21 #if defined(LIBC_SCCS) && !defined(lint) 22 static char sccsid[] = "@(#)swab.c 5.5 (Berkeley) 05/17/90"; 23 #endif /* LIBC_SCCS and not lint */ 24 25 #include <string.h> 26 27 void 28 swab(from, to, n) 29 register char *from, *to; 30 register int n; 31 { 32 register unsigned long temp; 33 34 n >>= 1; n++; 35 #define STEP temp = *from++,*to++ = *from++,*to++ = temp 36 /* round to multiple of 8 */ 37 while ((--n) & 07) 38 STEP; 39 n >>= 3; 40 while (--n >= 0) { 41 STEP; STEP; STEP; STEP; 42 STEP; STEP; STEP; STEP; 43 } 44 } 45