xref: /csrg-svn/lib/libc/tahoe/string/strncat.s (revision 34824)
134438Sbostic/*
234438Sbostic * Copyright (c) 1988 Regents of the University of California.
334438Sbostic * All rights reserved.
434438Sbostic *
5*34824Sbostic * Redistribution and use in source and binary forms are permitted
6*34824Sbostic * provided that the above copyright notice and this paragraph are
7*34824Sbostic * duplicated in all such forms and that any documentation,
8*34824Sbostic * advertising materials, and other materials related to such
9*34824Sbostic * distribution and use acknowledge that the software was developed
10*34824Sbostic * by the University of California, Berkeley.  The name of the
11*34824Sbostic * University may not be used to endorse or promote products derived
12*34824Sbostic * from this software without specific prior written permission.
13*34824Sbostic * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14*34824Sbostic * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15*34824Sbostic * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16*34824Sbostic *
1734438Sbostic * This code is derived from software contributed to Berkeley by
1834438Sbostic * Computer Consoles Inc.
1934438Sbostic */
2029700Ssam
2134438Sbostic#if defined(LIBC_SCCS) && !defined(lint)
22*34824Sbostic	.asciz "@(#)strncat.s	1.4 (Berkeley) 06/27/88"
2334438Sbostic#endif /* LIBC_SCCS and not lint */
2434438Sbostic
2529700Ssam/*
2629700Ssam * Concatenate s2 on the end of s1.  S1's space must be large enough.
2729700Ssam * At most n characters are moved.
2829700Ssam * Return s1.
2929700Ssam *
3029700Ssam * char *strncat(s1, s2, n)
3129700Ssam * register char *s1, *s2;
3229700Ssam * register n;
3329700Ssam */
3429700Ssam#include "DEFS.h"
3529700Ssam
3629700SsamENTRY(strncat, 0)
3729700Ssam	tstl	12(fp)
3829700Ssam	jgtr	n_ok
3929700Ssam	movl	4(fp),r0
4029700Ssam	ret
4129700Ssamn_ok:
4229700Ssam	movl	8(fp),r0
4329700Ssam	movl	r0,r1
4429700Ssam	cmps2			# r0 points at null at end of s2
4529700Ssam	subl3	8(fp),r0,r2	# r2 = numberof non-null chars in s2
4629700Ssam	cmpl	12(fp),r2
4729700Ssam	jgeq	r2_ok
4829700Ssam	movl	12(fp),r2	# r2 = min (n, length(s2))
4929700Ssamr2_ok:
5029700Ssam	movl	4(fp),r0
5129700Ssam	movl	r0,r1
5229700Ssam	cmps2			# r1 points at null at end of s1
5329700Ssam	movl	8(fp),r0	# source for copy
5429700Ssam	movs3			# actual copy
5529700Ssam	clrb	(r1)		# null terminated string !
5629700Ssam	movl	4(fp),r0
5729700Ssam	ret
58