mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 15:30:07 +00:00
91 lines
2.6 KiB
ArmAsm
91 lines
2.6 KiB
ArmAsm
/* strncpy - copy at most n characters from a string from source to
|
|
destination. 64 bit S/390 version
|
|
Copyright (C) 2001-2017 Free Software Foundation, Inc.
|
|
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* INPUT PARAMETERS
|
|
%r2 = address of destination (dst)
|
|
%r3 = address of source (src)
|
|
%r4 = max of bytes to copy. */
|
|
|
|
#include "sysdep.h"
|
|
#include "asm-syntax.h"
|
|
|
|
ENTRY(strncpy)
|
|
.text
|
|
stg %r2,48(%r15) # save dst pointer
|
|
slgr %r2,%r3 # %r3 points to src, %r2+%r3 to dst
|
|
lghi %r1,7
|
|
ngr %r1,%r4 # last 3 bits of # bytes
|
|
srlg %r4,%r4,3
|
|
ltgr %r4,%r4 # less than 8 bytes to copy ?
|
|
jz .L1
|
|
bras %r5,.L0 # enter loop & load address of a 0
|
|
.long 0
|
|
.L0: icmh %r0,8,0(%r3) # first byte
|
|
jz .L3
|
|
icmh %r0,4,1(%r3) # second byte
|
|
jz .L4
|
|
icmh %r0,2,2(%r3) # third byte
|
|
jz .L5
|
|
icmh %r0,1,3(%r3) # fourth byte
|
|
jz .L6
|
|
icm %r0,8,4(%r3) # fifth byte
|
|
jz .L7
|
|
icm %r0,4,5(%r3) # sixth byte
|
|
jz .L8
|
|
icm %r0,2,6(%r3) # seventh byte
|
|
jz .L9
|
|
icm %r0,1,7(%r3) # eigth byte
|
|
jz .L10
|
|
stg %r0,0(%r2,%r3) # store all eight to dest.
|
|
la %r3,8(%r3)
|
|
brct %r4,.L0
|
|
.L1: ltgr %r1,%r1
|
|
jz .Lexit
|
|
.L2: icm %r0,1,0(%r3)
|
|
stc %r0,0(%r2,%r3)
|
|
la %r3,1(%r3)
|
|
jz .L11
|
|
brct %r1,.L2
|
|
j .Lexit
|
|
.L3: icmh %r0,4,0(%r5)
|
|
.L4: icmh %r0,2,0(%r5)
|
|
.L5: icmh %r0,1,0(%r5)
|
|
.L6: icm %r0,8,0(%r5)
|
|
.L7: icm %r0,4,0(%r5)
|
|
.L8: icm %r0,2,0(%r5)
|
|
.L9: icm %r0,1,0(%r5)
|
|
.L10: stg %r0,0(%r2,%r3)
|
|
la %r3,8(%r3)
|
|
aghi %r4,-1
|
|
j .L12
|
|
.L11: aghi %r1,-1
|
|
.L12: sllg %r4,%r4,3
|
|
algr %r4,%r1
|
|
algr %r2,%r3 # start of dst area to be zeroed
|
|
lgr %r3,%r4
|
|
slgr %r4,%r4
|
|
slgr %r5,%r5
|
|
.L13: mvcle %r2,%r4,0 # pad dst with zeroes
|
|
jo .L13
|
|
.Lexit: lg %r2,48(%r15) # return dst pointer
|
|
br %r14
|
|
END(strncpy)
|
|
libc_hidden_builtin_def (strncpy)
|