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Alpha ev67 strncat implementation.

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Ulrich Drepper 2000-12-08 17:20:22 +00:00
parent 19db7d8141
commit 4eae4d050d
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sysdeps/alpha/alphaev67/strncat.S Normal file
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/* Copyright (C) 2000 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 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. */
/* 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 $16, $0 # set up return value
beq $18, $zerocount # U :
/* Find the end of the string. */
ldq_u $1, 0($16) # L : load first quadword ($16 may be misaligned)
lda $2, -1($31) # E :
insqh $2, $0, $2 # U :
andnot $16, 7, $16 # E :
nop # E :
or $2, $1, $1 # E :
nop # E :
nop # E :
cmpbge $31, $1, $2 # E : bits set iff byte == 0
bne $2, $found # U :
$loop: ldq $1, 8($16) # L :
addq $16, 8, $16 # E :
cmpbge $31, $1, $2 # E :
beq $2, $loop # U :
$found: cttz $2, $3 # U0 :
addq $16, $3, $16 # E :
jsr $23, __stxncpy # L0 :/* Now do the append. */
/* Worry about the null termination. */
zapnot $1, $27, $2 # U : was last byte a null?
cmplt $27, $24, $5 # E : did we fill the buffer completely?
bne $2, 0f # U :
ret # L0 :
0: or $5, $18, $2 # E :
nop
bne $2, 2f # U :
and $24, 0x80, $3 # E : no zero next byte
nop # E :
bne $3, 1f # U :
/* Here there are bytes left in the current word. Clear one. */
addq $24, $24, $24 # E : end-of-count bit <<= 1
nop # E :
2: zap $1, $24, $1 # U :
nop # E :
stq_u $1, 0($16) # L :
ret # L0 :
1: /* Here we must clear the first byte of the next DST word */
stb $31, 8($16) # L :
nop # E :
nop # E :
ret # L0 :
$zerocount:
nop # E :
nop # E :
nop # E :
ret # L0 :
END(strncat)