glibc/sysdeps/alpha/alphaev67/stpncpy.S

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2000-12-08 17:19:44 +00:00
/* Copyright (C) 2000 Free Software Foundation, Inc.
Contributed by Richard Henderson (rth@redhat.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. */
/* Copy no more then N bytes from SRC to DEST, returning the address of
the terminating '\0' in DEST. */
#include <sysdep.h>
.arch ev6
.set noat
.set noreorder
.text
ENTRY(__stpncpy)
ldgp gp, 0(pv)
#ifdef PROF
lda AT, _mcount
jsr AT, (AT), _mcount
#endif
.prologue 1
mov a0, v0
beq a2, $zerocount
.align 4
nop
nop
jsr t9, __stxncpy # do the work of the copy
cttz t8, t4
zapnot t0, t8, t5
andnot a0, 7, a0
bne a2, $multiword # do we have full words left?
subq t8, 1, t2
subq t10, 1, t3
cmpult zero, t5, t5
addq a0, t4, v0
or t2, t8, t2
or t3, t10, t3
addq v0, t5, v0
andnot t3, t2, t3
zap t0, t3, t0
nop
stq t0, 0(a0)
ret
$multiword:
subq t8, 1, t7 # clear the final bits in the prev word
cmpult zero, t5, t5
or t7, t8, t7
zapnot t0, t7, t0
subq a2, 1, a2
stq t0, 0(a0)
addq a0, 8, a1
beq a2, 1f # loop over full words remaining
nop
nop
nop
blbc a2, 0f
stq zero, 0(a1)
subq a2, 1, a2
addq a1, 8, a1
beq a2, 1f
0: stq zero, 0(a1)
subq a2, 2, a2
nop
nop
stq zero, 8(a1)
addq a1, 16, a1
nop
bne a2, 0b
1: ldq t0, 0(a1) # clear the leading bits in the final word
subq t10, 1, t7
addq a0, t4, v0
nop
or t7, t10, t7
addq v0, t5, v0
zap t0, t7, t0
stq t0, 0(a1)
$zerocount:
nop
nop
nop
ret
END(__stpncpy)
weak_alias (__stpncpy, stpncpy)