mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-22 10:50:07 +00:00
108 lines
3.5 KiB
ArmAsm
108 lines
3.5 KiB
ArmAsm
/*
|
|
* 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 occurrence 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
|
|
|
|
weak_alias (strchr, index)
|