94 lines
2.2 KiB
ArmAsm
94 lines
2.2 KiB
ArmAsm
|
/* Copyright (C) 1996-2022 Free Software Foundation, Inc.
|
||
|
|
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
|
||
|
|
<https://www.gnu.org/licenses/>. */
|
||
|
|
|
||
|
|
/* Append no more than COUNT characters from the null-terminated string SRC
|
||
|
|
to the null-terminated string DST. Always null-terminate the new DST. */
|
||
|
|
|
||
|
|
#include <sysdep.h>
|
||
|
|
|
||
|
|
.text
|
||
|
|
|
||
|
|
ENTRY(strncat)
|
||
|
|
ldgp gp, 0(pv)
|
||
|
|
#ifdef PROF
|
||
|
|
.set noat
|
||
|
|
lda AT, _mcount
|
||
|
|
jsr AT, (AT), _mcount
|
||
|
|
.set at
|
||
|
|
#endif
|
||
|
|
.prologue 1
|
||
|
|
|
||
|
|
mov a0, v0 # set up return value
|
||
|
|
beq a2, $zerocount
|
||
|
|
|
||
|
|
/* Find the end of the string. */
|
||
|
|
|
||
|
|
ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned)
|
||
|
|
lda t1, -1(zero)
|
||
|
|
insqh t1, a0, t1
|
||
|
|
andnot a0, 7, a0
|
||
|
|
or t1, t0, t0
|
||
|
|
cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0
|
||
|
|
bne t1, $found
|
||
|
|
|
||
|
|
$loop: ldq t0, 8(a0)
|
||
|
|
addq a0, 8, a0 # addr += 8
|
||
|
|
cmpbge zero, t0, t1
|
||
|
|
beq t1, $loop
|
||
|
|
|
||
|
|
$found: negq t1, t2 # clear all but least set bit
|
||
|
|
and t1, t2, t1
|
||
|
|
|
||
|
|
and t1, 0xf0, t2 # binary search for that set bit
|
||
|
|
and t1, 0xcc, t3
|
||
|
|
and t1, 0xaa, t4
|
||
|
|
cmovne t2, 4, t2
|
||
|
|
cmovne t3, 2, t3
|
||
|
|
cmovne t4, 1, t4
|
||
|
|
addq t2, t3, t2
|
||
|
|
addq a0, t4, a0
|
||
|
|
addq a0, t2, a0
|
||
|
|
|
||
|
|
/* Now do the append. */
|
||
|
|
|
||
|
|
jsr t9, __stxncpy
|
||
|
|
|
||
|
|
/* Worry about the null termination. */
|
||
|
|
|
||
|
|
zapnot t0, t8, t1 # was last byte a null?
|
||
|
|
bne t1, 0f
|
||
|
|
ret
|
||
|
|
|
||
|
|
0: and t10, 0x80, t1
|
||
|
|
bne t1, 1f
|
||
|
|
|
||
|
|
/* Here there are bytes left in the current word. Clear one. */
|
||
|
|
addq t10, t10, t10 # end-of-count bit <<= 1
|
||
|
|
zap t0, t10, t0
|
||
|
|
stq_u t0, 0(a0)
|
||
|
|
ret
|
||
|
|
|
||
|
|
1: /* Here we must read the next DST word and clear the first byte. */
|
||
|
|
ldq_u t0, 8(a0)
|
||
|
|
zap t0, 1, t0
|
||
|
|
stq_u t0, 8(a0)
|
||
|
|
|
||
|
|
$zerocount:
|
||
|
|
ret
|
||
|
|
|
||
|
|
END(strncat)
|