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/* Optimized strcpy implementation for PowerPC476.
Copyright (C) 2010 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
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <bp-sym.h>
#include <bp-asm.h>
/* strcpy
Register Use
r3:destination and return address
r4:source address
r10:temp destination address
Implementation description
Loop by checking 2 words at a time, with dlmzb. Check if there is a null
in the 2 words. If there is a null jump to end checking to determine
where in the last 8 bytes it is. Copy the appropriate bytes of the last
8 according to the null position. */
EALIGN (BP_SYM (strcpy), 5, 0)
neg r7,r4
subi r4,r4,1
clrlwi. r8,r7,29
subi r10,r3,1
beq L(pre_word8_loop)
mtctr r8
L(loop):
lbzu r5,0x01(r4)
cmpi cr5,r5,0x0
stbu r5,0x01(r10)
beq cr5,L(end_strcpy)
bdnz L(loop)
L(pre_word8_loop):
subi r4,r4,3
subi r10,r10,3
L(word8_loop):
lwzu r5,0x04(r4)
lwzu r6,0x04(r4)
dlmzb. r11,r5,r6
bne L(byte_copy)
stwu r5,0x04(r10)
stwu r6,0x04(r10)
lwzu r5,0x04(r4)
lwzu r6,0x04(r4)
dlmzb. r11,r5,r6
bne L(byte_copy)
stwu r5,0x04(r10)
stwu r6,0x04(r10)
lwzu r5,0x04(r4)
lwzu r6,0x04(r4)
dlmzb. r11,r5,r6
bne L(byte_copy)
stwu r5,0x04(r10)
stwu r6,0x04(r10)
lwzu r5,0x04(r4)
lwzu r6,0x04(r4)
dlmzb. r11,r5,r6
bne L(byte_copy)
stwu r5,0x04(r10)
stwu r6,0x04(r10)
b L(word8_loop)
L(last_bytes_copy):
stwu r5,0x04(r10)
subi r11,r11,4
mtctr r11
addi r10,r10,3
subi r4,r4,1
L(last_bytes_copy_loop):
lbzu r5,0x01(r4)
stbu r5,0x01(r10)
bdnz L(last_bytes_copy_loop)
blr
L(byte_copy):
blt L(last_bytes_copy)
mtctr r11
addi r10,r10,3
subi r4,r4,5
L(last_bytes_copy_loop2):
lbzu r5,0x01(r4)
stbu r5,0x01(r10)
bdnz L(last_bytes_copy_loop2)
L(end_strcpy):
blr
END (BP_SYM (strcpy))
libc_hidden_builtin_def (strcpy)
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