glibc/sysdeps/alpha/alphaev67/strncat.S

88 lines
2.2 KiB
ArmAsm

/* Copyright (C) 2000-2020 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@tamu.edu>, 1996.
EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.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
<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>
.arch ev6
.set noreorder
.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 # U :
/* Find the end of the string. */
ldq_u t0, 0(a0) # L : load first quadword (a0 may be misaligned)
lda t1, -1 # E :
insqh t1, v0, t1 # U :
andnot a0, 7, a0 # E :
nop # E :
or t1, t0, t0 # E :
nop # E :
nop # E :
cmpbge zero, t0, t1 # E : bits set iff byte == 0
bne t1, $found # U :
$loop: ldq t0, 8(a0) # L :
addq a0, 8, a0 # E :
cmpbge zero, t0, t1 # E :
beq t1, $loop # U :
$found: cttz t1, t2 # U0 :
addq a0, t2, a0 # E :
jsr t9, __stxncpy # L0 : Now do the append.
/* Worry about the null termination. */
cttz t10, t2 # U0: byte offset of end-of-count.
bic a0, 7, a0 # E : word align the last write address.
zapnot t0, t8, t1 # U : was last byte a null?
nop # E :
bne t1, 0f # U :
nop # E :
nop # E :
ret # L0 :
0: addq t2, a0, a0 # E : address of end-of-count
stb zero, 1(a0) # L :
nop # E :
ret # L0 :
$zerocount:
nop # E :
nop # E :
nop # E :
ret # L0 :
END(strncat)