diff options
Diffstat (limited to 'sysdeps/vax/strchr.s')
| -rw-r--r-- | sysdeps/vax/strchr.s | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/sysdeps/vax/strchr.s b/sysdeps/vax/strchr.s new file mode 100644 index 0000000000..18b53838ec --- /dev/null +++ b/sysdeps/vax/strchr.s @@ -0,0 +1,105 @@ +/* + * Copyright (c) 1988 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 "@(#)strchr.s 5.4 (Berkeley) 6/1/90" +#endif /* LIBC_SCCS and not lint */ + +/* + * Find the first occurence of c in the string cp. + * Return pointer to match or null pointer. + * + * char * + * strchr(cp, c) + * char *cp, c; + */ +#include "DEFS.h" + + .lcomm tbl,256 + +ENTRY(strchr, 0) + movzwl $65535,r4 /* handy constant */ + movq 4(ap),r1 /* r1 = cp; r2 = c */ + movzbl r2,r2 + beql Lzero /* special case for c == '\0' */ + +/* + * Fancy scanc version. Alas, it is not reentrant. + */ + movab tbl,r3 /* r3 = base of table */ + bbss $0,(r3),Lreent /* ensure not reentering */ + movab (r3)[r2],r5 + incb (r5) /* mark both '\0' and c */ +0: + scanc r4,(r1),(r3),$1 /* look for c or '\0' */ + beql 0b /* still looking */ + movl r1,r0 /* return whatever we found */ + tstb (r0) + bneq 1f # unless it was '\0': + clrl r0 # then return NULL +1: + clrb (r5) /* clean up table */ + clrb (r3) + ret + +/* + * Special case for \0. + */ +Lzero: + locc r2,r4,(r1) /* just find end of string */ + beql Lzero /* still looking */ + movl r1,r0 /* found it */ + ret + +/* + * Slower reentrant version is two two-step searches. The first + * phase runs until we know where the string ends; it locates the + * first occurrence of c within a 65535-byte block. If we find + * the end of the string first, we switch to the second phase, + * were we look only up to the known end of string. + */ +Lreent: +0: /* first phase */ + movl r1,r3 + locc $0,r4,(r3) /* look for '\0' */ + bneq 1f + locc r2,r4,(r3) /* look for c */ + beql 0b /* not found: reset pointer and loop */ + movl r1,r0 /* found: return it */ + ret +1: /* second phase */ + subl3 r3,r1,r0 /* length of short block */ + locc r2,r0,(r3) /* look for c */ + beql 2f /* not found: return NULL */ + movl r1,r0 +2: ret |