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/* Copy SRC to DEST returning the address of the terminating '\0' in DEST.
For SPARC v7.
Copyright (C) 1996-2024 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/>. */
#include <sysdep.h>
/* Normally, this uses ((xword - 0x01010101) & 0x80808080) test
to find out if any byte in xword could be zero. This is fast, but
also gives false alarm for any byte in range 0x81-0xff. It does
not matter for correctness, as if this test tells us there could
be some zero byte, we check it byte by byte, but if bytes with
high bits set are common in the strings, then this will give poor
performance. You can #define EIGHTBIT_NOT_RARE and the algorithm
will use one tick slower, but more precise test
((xword - 0x01010101) & (~xword) & 0x80808080),
which does not give any false alarms (but if some bits are set,
one cannot assume from it which bytes are zero and which are not).
It is yet to be measured, what is the correct default for glibc
in these days for an average user.
*/
.text
.align 4
ENTRY(__stpcpy)
andcc %o1, 3, %g0
be 20f
sethi %hi(0x80808080), %o4
ldub [%o1], %o5
stb %o5, [%o0]
cmp %o5, 0
add %o0, 1, %o0
be 1f
add %o1, 1, %o1
andcc %o1, 3, %g0
be 4f
or %o4, %lo(0x80808080), %o3
ldub [%o1], %o5
stb %o5, [%o0]
cmp %o5, 0
add %o0, 1, %o0
be 1f
add %o1, 1, %o1
andcc %o1, 3, %g0
be 5f
sethi %hi(0x01010101), %o4
ldub [%o1], %o5
stb %o5, [%o0]
cmp %o5, 0
add %o0, 1, %o0
be 1f
add %o1, 1, %o1
b 6f
or %o4, %lo(0x01010101), %o2
1: retl
add %o0, -1, %o0
20: or %o4, %lo(0x80808080), %o3
4: sethi %hi(0x01010101), %o4
5: or %o4, %lo(0x01010101), %o2
6: andcc %o0, 3, %g0
bne 16f
sub %g0, 4, %g1
11: add %g1, 4, %g1
ld [%o1 + %g1], %o5
sub %o5, %o2, %o4
#ifdef EIGHTBIT_NOT_RARE
andn %o4, %o5, %o4
#endif
andcc %o4, %o3, %g0
be,a 11b
st %o5, [%o0 + %g1]
/* Check every byte. */
srl %o5, 24, %g5
andcc %g5, 0xff, %g0
be 14f
srl %o5, 16, %g5
andcc %g5, 0xff, %g0
be 13f
srl %o5, 8, %g5
andcc %g5, 0xff, %g0
be 12f
andcc %o5, 0xff, %g0
bne 11b
st %o5, [%o0 + %g1]
add %o0, %g1, %o0
retl
add %o0, 3, %o0
12: srl %o5, 16, %o5
sth %o5, [%o0 + %g1]
add %g1, 2, %g1
stb %g0, [%o0 + %g1]
retl
add %o0, %g1, %o0
13: srl %o5, 16, %o5
sth %o5, [%o0 + %g1]
add %g1, 1, %g1
retl
add %o0, %g1, %o0
14: stb %g0, [%o0 + %g1]
retl
add %o0, %g1, %o0
15: srl %o5, 24, %o4
srl %o5, 16, %g1
stb %o4, [%o0]
srl %o5, 8, %g4
stb %g1, [%o0 + 1]
stb %g4, [%o0 + 2]
stb %o5, [%o0 + 3]
add %o0, 4, %o0
16: ld [%o1], %o5
sub %o5, %o2, %o4
andcc %o4, %o3, %g0
be 15b
add %o1, 4, %o1
/* Check every byte. */
srl %o5, 24, %g5
andcc %g5, 0xff, %g4
be 19f
stb %g4, [%o0]
srl %o5, 16, %g5
andcc %g5, 0xff, %g4
be 18f
stb %g4, [%o0 + 1]
srl %o5, 8, %g5
andcc %g5, 0xff, %g4
be 17f
stb %g4, [%o0 + 2]
andcc %o5, 0xff, %g4
stb %g4, [%o0 + 3]
bne 16b
add %o0, 4, %o0
retl
sub %o0, 1, %o0
17: retl
add %o0, 2, %o0
18: retl
add %o0, 1, %o0
19: retl
nop
END(__stpcpy)
weak_alias (__stpcpy, stpcpy)
libc_hidden_def (__stpcpy)
libc_hidden_builtin_def (stpcpy)
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