mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-30 10:45:40 +03:00
88 lines
2.3 KiB
ArmAsm
88 lines
2.3 KiB
ArmAsm
/* Copyright (C) 1996-2016 Free Software Foundation, Inc.
|
|
Contributed by Richard Henderson (rth@tamu.edu)
|
|
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/>. */
|
|
|
|
/* Copy no more than COUNT bytes of the null-terminated string from
|
|
SRC to DST. If SRC does not cover all of COUNT, the balance is
|
|
zeroed. */
|
|
|
|
#include <sysdep.h>
|
|
|
|
.set noat
|
|
.set noreorder
|
|
|
|
.text
|
|
|
|
ENTRY(strncpy)
|
|
ldgp gp, 0(pv)
|
|
#ifdef PROF
|
|
lda AT, _mcount
|
|
jsr AT, (AT), _mcount
|
|
#endif
|
|
.prologue 1
|
|
|
|
mov a0, v0 # set return value now
|
|
beq a2, $zerocount
|
|
jsr t9, __stxncpy # do the work of the copy
|
|
|
|
bne a2, $multiword # do we have full words left?
|
|
|
|
.align 3
|
|
subq t8, 1, t2 # e0 : guess not
|
|
subq t10, 1, t3 # .. e1 :
|
|
or t2, t8, t2 # e0 : clear the bits between the last
|
|
or t3, t10, t3 # .. e1 : written byte and the last byte in
|
|
andnot t3, t2, t3 # e0 : COUNT
|
|
zap t0, t3, t0 # e1 :
|
|
stq_u t0, 0(a0) # e0 :
|
|
ret # .. e1 :
|
|
|
|
$multiword:
|
|
subq t8, 1, t7 # e0 : clear the final bits in the prev
|
|
or t7, t8, t7 # e1 : word
|
|
zapnot t0, t7, t0 # e0 :
|
|
subq a2, 1, a2 # .. e1 :
|
|
stq_u t0, 0(a0) # e0 :
|
|
addq a0, 8, a0 # .. e1 :
|
|
|
|
beq a2, 1f # e1 :
|
|
blbc a2, 0f # e1 :
|
|
|
|
stq_u zero, 0(a0) # e0 : zero one word
|
|
subq a2, 1, a2 # .. e1 :
|
|
addq a0, 8, a0 # e0 :
|
|
beq a2, 1f # .. e1 :
|
|
|
|
0: stq_u zero, 0(a0) # e0 : zero two words
|
|
subq a2, 2, a2 # .. e1 :
|
|
stq_u zero, 8(a0) # e0 :
|
|
addq a0, 16, a0 # .. e1 :
|
|
bne a2, 0b # e1 :
|
|
unop
|
|
|
|
1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final
|
|
subq t10, 1, t7 # .. e1 : word
|
|
or t7, t10, t7 # e0 :
|
|
zap t0, t7, t0 # e1 (stall)
|
|
stq_u t0, 0(a0) # e0 :
|
|
|
|
$zerocount:
|
|
ret # .. e1 :
|
|
|
|
END(strncpy)
|
|
libc_hidden_builtin_def (strncpy)
|