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Diffstat (limited to 'sysdeps/vax/strrchr.s')
| -rw-r--r-- | sysdeps/vax/strrchr.s | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/sysdeps/vax/strrchr.s b/sysdeps/vax/strrchr.s new file mode 100644 index 0000000000..f292eaceab --- /dev/null +++ b/sysdeps/vax/strrchr.s @@ -0,0 +1,114 @@ +/* + * 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 "@(#)strrchr.s 5.4 (Berkeley) 6/1/90" +#endif /* LIBC_SCCS and not lint */ + +/* + * Find the last occurence of c in the string cp. + * Return pointer to match or null pointer. + * + * char * + * strrchr(cp, c) + * char *cp, c; + */ +#include "DEFS.h" + + .lcomm tbl,256 + +ENTRY(strrchr, 0) + movzwl $65535,r4 /* handy 65535 */ + movq 4(ap),r1 /* r1 = cp; r2 = c */ + movzbl r2,r2 + beql Lzero /* special case for c == '\0' */ + + clrl r5 /* r5 = pointer to last match */ + +/* + * Fancy scanc version. Alas, it is not reentrant. + */ + movab tbl,r3 /* r3 = address of table */ + bbss $0,(r3),Lreent /* ensure not reentering */ + movab (r3)[r2],r4 + incb (r4) /* mark both '\0' and c */ +0: + scanc $65535,(r1),(r3),$1 /* look for c or '\0' */ + beql 0b /* keep looking */ + tstb (r1) + beql 1f /* done if '\0' */ + movab (r1)+,r5 /* save most recently found, and skip over it */ + jbr 0b /* keep looking */ +1: + movl r5,r0 /* return last found (if any) */ + clrb (r4) /* clean up table */ + clrb (r3) + ret + +/* + * Special case for \0. + */ +Lzero: + locc $0,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 any + * occurrences of c within a 65535-byte block. Once we have found + * the end of the string, we find any further occurrences before + * that location. + */ +Lreent: +0: /* first phase */ + movl r1,r3 + locc $0,r4,(r3) /* look for '\0' */ + bneq 1f + locc r2,r4,(r3) /* continue phase 1 search for c */ + beql 0b + movab (r1)+,r5 /* found c: save and increment pointer */ + brb 0b /* and continue */ + +1: /* second phase */ + subl3 r3,r1,r0 /* length of short block */ + movl r3,r1 +2: + locc r2,r0,(r1) /* look for c */ + beql 3f /* skip if not found */ + movab (r1)+,r5 /* save pointer as before */ + sobgtr r0,2b /* adjust count and loop */ +3: + movl r5,r0 /* return stashed pointer */ + ret |