diff options
Diffstat (limited to 'sysdeps/vax/strstr.s')
| -rw-r--r-- | sysdeps/vax/strstr.s | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/vax/strstr.s b/sysdeps/vax/strstr.s new file mode 100644 index 0000000000..2e5337595d --- /dev/null +++ b/sysdeps/vax/strstr.s @@ -0,0 +1,113 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) + .asciz "@(#)strstr.s 5.2 (Berkeley) 8/21/90" +#endif /* LIBC_SCCS and not lint */ + +/* + * Find the first occurrence of s2 as a substring in s1. + * If s2 is empty, return s1. + * + * char *strstr(s1, s2) + * const char *s1, *s2; + */ +#include "DEFS.h" + +ENTRY(strstr, 0) + movq 4(ap),r3 /* r3 = s1, r4 = s2 */ + movzwl $65535,r2 /* r2 = locc/matchc limit */ + locc $0,r2,(r4) /* find '\0' in s2 */ + beql 4f + subl3 r4,r1,r5 /* r5 = strlen(s2) */ + beql 1f /* if r5 == 0, return s1 */ + + /* + * s2 is short enough to apply matchc. + * If s1 is long, we have to do it in stages. + */ +0: locc $0,r2,(r3) /* find '\0' in s1 */ + beql 3f + + /* + * Both strings are `short'; we can use matchc directly. + */ + subl3 r3,r1,r1 /* r1 = strlen(s1) */ + matchc r5,(r4),r1,(r3) /* find substring */ + bneq 2f + + /* + * r3 points r5 bytes past match. Return the match. + */ +1: subl3 r5,r3,r0 /* return (byte_past_match - strlen(s2)) */ + ret + + /* + * There is no matching substring. + */ +2: clrl r0 /* return NULL */ + ret + + /* + * s1 is too long (> 65535 bytes) to apply matchc directly, + * but s2 is short enough. Apply s2 to s1, then (if not + * found yet) advancing s1 by (65536-strlen(s2)) bytes and + * loop. + */ +3: matchc r5,(r4),r2,(r3) /* search */ + beql 1b /* if found, go return it */ + decw r2 /* from 0 to 65535 */ + incl r3 /* already advanced 65535, now 65536 */ + subl2 r5,r3 /* ... minus strlen(s2) */ + brb 0b + + /* + * s2 is too long (> 65535 bytes) to bother with matchc. + */ +4: locc $0,r2,(r1) /* continue working on strlen(s2) */ + beql 4b + subl3 r1,r4,r5 /* r5 = strlen(s2) */ + movb (r4)+,r2 /* r2 = *s2++ */ + decl r5 /* fix up length */ +5: movb (r3)+,r0 /* r0 = *s1++ */ + beql 2b /* if '\0', return NULL */ + cmpb r0,r2 + bneq 5b /* loop until first char found */ + pushr R5|R4|R3|R2 /* save c, s1, s2, n */ + pushr R5|R4|R3 /* strncmp(s1, s2, n) */ + calls $3,_strncmp + popr R2|R3|R4|R5 /* restore */ + tstl r0 + bneq 5b /* loop until strncmp says rest same too */ + subl3 $1,r3,r0 /* return previous s1 */ + ret |