mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-23 11:20:07 +00:00
85 lines
3.0 KiB
ArmAsm
85 lines
3.0 KiB
ArmAsm
|
/*
|
||
|
|
* 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 "@(#)strncpy.s 5.6 (Berkeley) 6/1/90"
|
||
|
|
#endif /* LIBC_SCCS and not lint */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copy string s2 over top of string s1.
|
||
|
|
* Truncate or null-pad to n bytes.
|
||
|
|
*
|
||
|
|
* char *
|
||
|
|
* strncpy(s1, s2, n)
|
||
|
|
* char *s1, *s2;
|
||
|
|
*/
|
||
|
|
#include "DEFS.h"
|
||
|
|
|
||
|
|
ENTRY(strncpy, R6)
|
||
|
|
movl 12(ap),r6 # r6 = n
|
||
|
|
bleq done # n <= 0
|
||
|
|
movl 4(ap),r3 # r3 = s1
|
||
|
|
movl 8(ap),r1 # r1 = s2
|
||
|
|
1:
|
||
|
|
movzwl $65535,r2 # r2 = bytes in first chunk
|
||
|
|
cmpl r6,r2 # r2 = min(bytes in chunk, n);
|
||
|
|
jgeq 2f
|
||
|
|
movl r6,r2
|
||
|
|
2:
|
||
|
|
subl2 r2,r6 # update n
|
||
|
|
locc $0,r2,(r1) # '\0' found?
|
||
|
|
jneq 3f
|
||
|
|
subl2 r2,r1 # back up pointer updated by locc
|
||
|
|
movc3 r2,(r1),(r3) # copy in next piece
|
||
|
|
tstl r6 # run out of space?
|
||
|
|
jneq 1b
|
||
|
|
jbr done
|
||
|
|
3: # copy up to '\0' logic
|
||
|
|
addl2 r0,r6 # r6 = number of null-pad bytes
|
||
|
|
subl2 r0,r2 # r2 = number of bytes to move
|
||
|
|
subl2 r2,r1 # back up pointer updated by locc
|
||
|
|
movc3 r2,(r1),(r3) # copy in last piece
|
||
|
|
4: # null-pad logic
|
||
|
|
movzwl $65535,r2 # r2 = bytes in first chunk
|
||
|
|
cmpl r6,r2 # r2 = min(bytes in chunk, n);
|
||
|
|
jgeq 5f
|
||
|
|
movl r6,r2
|
||
|
|
5:
|
||
|
|
subl2 r2,r6 # update n
|
||
|
|
movc5 $0,(r3),$0,r2,(r3)# pad with '\0's
|
||
|
|
tstl r6 # finished padding?
|
||
|
|
jneq 4b
|
||
|
|
done:
|
||
|
|
movl 4(ap),r0 # return s1
|
||
|
|
ret
|