Remove .cvsignore files
[glibc-ports.git] / sysdeps / vax / strchr.s
blobd56cb4b0a0718e7cbd03fc68c772537d23da15a7
1 /*
2 * Copyright (c) 1988 Regents of the University of California.
3 * All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
30 #if defined(LIBC_SCCS) && !defined(lint)
31 .asciz "@(#)strchr.s 5.4 (Berkeley) 6/1/90"
32 #endif /* LIBC_SCCS and not lint */
35 * Find the first occurrence of c in the string cp.
36 * Return pointer to match or null pointer.
38 * char *
39 * strchr(cp, c)
40 * char *cp, c;
42 #include "DEFS.h"
44 .lcomm tbl,256
46 ENTRY(strchr, 0)
47 movzwl $65535,r4 /* handy constant */
48 movq 4(ap),r1 /* r1 = cp; r2 = c */
49 movzbl r2,r2
50 beql Lzero /* special case for c == '\0' */
53 * Fancy scanc version. Alas, it is not reentrant.
55 movab tbl,r3 /* r3 = base of table */
56 bbss $0,(r3),Lreent /* ensure not reentering */
57 movab (r3)[r2],r5
58 incb (r5) /* mark both '\0' and c */
60 scanc r4,(r1),(r3),$1 /* look for c or '\0' */
61 beql 0b /* still looking */
62 movl r1,r0 /* return whatever we found */
63 tstb (r0)
64 bneq 1f # unless it was '\0':
65 clrl r0 # then return NULL
67 clrb (r5) /* clean up table */
68 clrb (r3)
69 ret
72 * Special case for \0.
74 Lzero:
75 locc r2,r4,(r1) /* just find end of string */
76 beql Lzero /* still looking */
77 movl r1,r0 /* found it */
78 ret
81 * Slower reentrant version is two two-step searches. The first
82 * phase runs until we know where the string ends; it locates the
83 * first occurrence of c within a 65535-byte block. If we find
84 * the end of the string first, we switch to the second phase,
85 * were we look only up to the known end of string.
87 Lreent:
88 0: /* first phase */
89 movl r1,r3
90 locc $0,r4,(r3) /* look for '\0' */
91 bneq 1f
92 locc r2,r4,(r3) /* look for c */
93 beql 0b /* not found: reset pointer and loop */
94 movl r1,r0 /* found: return it */
95 ret
96 1: /* second phase */
97 subl3 r3,r1,r0 /* length of short block */
98 locc r2,r0,(r3) /* look for c */
99 beql 2f /* not found: return NULL */
100 movl r1,r0
101 2: ret
103 weak_alias (strchr, index)