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/*
* Copyright (c) 1983 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 "@(#)rindex.s 5.6 (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 *
* rindex(cp, c)
* char *cp, c;
*/
#include "DEFS.h"
ENTRY(rindex, 0)
movq 4(ap),r1 # r1 = cp; r2 = c
tstl r2 # check for special case c == '\0'
bneq 2f
1:
locc $0,$65535,(r1) # just find end of string
beql 1b # still looking
movl r1,r0 # found it
ret
2:
moval tbl,r3 # r3 = address of table
bbss $0,(r3),5f # insure not reentering
movab (r3)[r2],r5 # table entry for c
incb (r5)
clrl r4 # last found
3:
scanc $65535,(r1),(r3),$1 # look for c or '\0'
beql 3b # keep looking
tstb (r1) # if have found '\0'
beql 4f # we are done
movl r1,r4 # save most recently found
incl r1 # skip over character
jbr 3b # keep looking
4:
movl r4,r0 # return last found (if any)
clrb (r5) # clean up table
clrb (r3)
ret
.data
tbl: .space 256
.text
/*
* Reentrant, but slower version of rindex
*/
5:
movl r1,r3
clrl r4 # r4 = pointer to last match
6:
locc $0,$65535,(r3) # look for '\0'
bneq 8f
decw r0 # r0 = 65535
1:
locc r2,r0,(r3) # look for c
bneq 7f
movl r1,r3 # reset pointer and ...
jbr 6b # ... try again
7:
movl r1,r4 # stash pointer ...
addl3 $1,r1,r3 # ... skip over match and ...
decl r0 # ... decrement count
jbr 6b # ... try again
8:
subl3 r3,r1,r0 # length of short block
incl r0 # +1 for '\0'
9:
locc r2,r0,(r3) # look for c
beql 0f
movl r1,r4 # stash pointer ...
addl3 $1,r1,r3 # ... skip over match ...
decl r0 # ... adjust count and ...
jbr 9b # ... try again
0:
movl r4,r0 # return stashed pointer
ret
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