xref: /csrg-svn/lib/libc/vax/string/index.s (revision 17329)
1/*	index.s	4.2	84/11/01	*/
2
3/*
4 * Find the first occurence of c in the string cp.
5 * Return pointer to match or null pointer.
6 *
7 * char *
8 * index(cp, c)
9 *	char *cp, c;
10 */
11#include "DEFS.h"
12
13ENTRY(index, 0)
14	movq	4(ap),r1	# r1 = cp; r2 = c
15	tstl	r2		# check for special case c == '\0'
16	bneq	2f
171:
18	locc	$0,$65535,(r1)	# just find end of string
19	beql	1b		# still looking
20	movl	r1,r0		# found it
21	ret
222:
23	movab	tbl[r2],r5	# table entry for c
24	incb	(r5)
25	movzwl	$65535,r4	# fast access
263:
27	scanc	r4,(r1),tbl,$1	# look for c or '\0'
28	beql	3b		# still looking
29	movl	r1,r0		# return pointer to char
30	tstb	(r0)		#    if have found '\0'
31	bneq	4f
32	clrl	r0		# else return 0
334:
34	clrb	(r5)		# clean up table
35	ret
36
37	.data
38tbl:	.byte	1
39	.space	255
40	.text
41