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/* Optimized strcpy implementation for PowerPC.
Copyright (C) 1997, 1999 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 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. */
#include <sysdep.h>
/* See strlen.s for comments on how the end-of-string testing works. */
EALIGN(strcpy,4,0)
/* char * [r3] strcpy (char *dest [r3], const char *src [r4]) */
/* General register assignments:
r0: temporary
r3: saved `dest'
r4: pointer to previous word in src
r5: pointer to previous word in dest
r6: current word from src
r7: 0xfefefeff
r8: 0x7f7f7f7f
r9: ~(word in src | 0x7f7f7f7f)
r10: alternate word from src. */
or r0,r4,r3
clrlwi. r0,r0,30
addi r5,r3,-4
bne L(unaligned)
lis r7,0xfeff
lis r8,0x7f7f
lwz r6,0(r4)
addi r7,r7,-0x101
addi r8,r8,0x7f7f
b 2f
0: lwzu r10,4(r4)
stwu r6,4(r5)
add r0,r7,r10
nor r9,r8,r10
and. r0,r0,r9
bne- 1f
lwzu r6,4(r4)
stwu r10,4(r5)
2: add r0,r7,r6
nor r9,r8,r6
and. r0,r0,r9
beq+ 0b
mr r10,r6
/* We've hit the end of the string. Do the rest byte-by-byte. */
1: rlwinm. r0,r10,8,24,31
stb r0,4(r5)
beqlr-
rlwinm. r0,r10,16,24,31
stb r0,5(r5)
beqlr-
rlwinm. r0,r10,24,24,31
stb r0,6(r5)
beqlr-
stb r10,7(r5)
blr
/* Oh well. In this case, we just do a byte-by-byte copy. */
.align 4
nop
L(unaligned):
lbz r6,0(r4)
addi r5,r3,-1
cmpwi r6,0
beq- 2f
0: lbzu r10,1(r4)
stbu r6,1(r5)
cmpwi r10,0
beq- 1f
nop /* Let 601 load start of loop. */
lbzu r6,1(r4)
stbu r10,1(r5)
cmpwi r6,0
bne+ 0b
2: stb r6,1(r5)
blr
1: stb r10,1(r5)
blr
END(strcpy)
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