80 lines
2.4 KiB
ArmAsm
80 lines
2.4 KiB
ArmAsm
/* strncpy - copy at most n characters from a string from source to
|
|
destination. For IBM S390
|
|
This file is part of the GNU C Library.
|
|
Copyright (C) 2000, 2001 Free Software Foundation, Inc.
|
|
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
|
|
|
|
The GNU C Library is free software ; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation ; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
/*
|
|
* 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
|
|
st %r2,24(%r15) # save dst pointer
|
|
slr %r2,%r3 # %r3 points to src, %r2+%r3 to dst
|
|
lhi %r1,3
|
|
nr %r1,%r4 # last 2 bits of # bytes
|
|
srl %r4,2
|
|
ltr %r4,%r4 # less than 4 bytes to copy ?
|
|
jz .L1
|
|
bras %r5,.L0 # enter loop & load address of a 0
|
|
.long 0
|
|
.L0: icm %r0,8,0(%r3) # first byte
|
|
jz .L3
|
|
icm %r0,4,1(%r3) # second byte
|
|
jz .L4
|
|
icm %r0,2,2(%r3) # third byte
|
|
jz .L5
|
|
icm %r0,1,3(%r3) # fourth byte
|
|
jz .L6
|
|
st %r0,0(%r2,%r3) # store all four to dest.
|
|
la %r3,4(%r3)
|
|
brct %r4,.L0
|
|
.L1: ltr %r1,%r1
|
|
jz .Lexit
|
|
.L2: icm %r0,1,0(%r3)
|
|
stc %r0,0(%r2,%r3)
|
|
la %r3,1(%r3)
|
|
jz .L7
|
|
brct %r1,.L2
|
|
j .Lexit
|
|
.L3: icm %r0,4,0(%r5)
|
|
.L4: icm %r0,2,0(%r5)
|
|
.L5: icm %r0,1,0(%r5)
|
|
.L6: st %r0,0(%r2,%r3)
|
|
la %r3,4(%r3)
|
|
ahi %r4,-1
|
|
j .L8
|
|
.L7: ahi %r1,-1
|
|
.L8: sll %r4,2
|
|
alr %r4,%r1
|
|
alr %r2,%r3 # start of dst area to be zeroed
|
|
lr %r3,%r4
|
|
slr %r4,%r4
|
|
slr %r5,%r5
|
|
.L9: mvcle %r2,%r4,0 # pad dst with zeroes
|
|
jo .L9
|
|
.Lexit: l %r2,24(%r15) # return dst pointer
|
|
br %r14
|
|
END(strncpy)
|