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/* Optimized memcpy 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>
/* memcpy
r0:return address
r3:destination address
r4:source address
r5:byte count
Save return address in r0.
If destinationn and source are unaligned and copy count is greater than 256
then copy 0-3 bytes to make destination aligned.
If 32 or more bytes to copy we use 32 byte copy loop.
Finaly we copy 0-31 extra bytes. */
EALIGN (BP_SYM (memcpy), 5, 0)
/* Check if bytes to copy are greater than 256 and if
source and destination are unaligned */
cmpwi r5,0x0100
addi r0,r3,0
ble L(string_count_loop)
neg r6,r3
clrlwi. r6,r6,30
beq L(string_count_loop)
neg r6,r4
clrlwi. r6,r6,30
beq L(string_count_loop)
mtctr r6
subf r5,r6,r5
L(unaligned_bytecopy_loop): /* Align destination by coping 0-3 bytes */
lbz r8,0x0(r4)
addi r4,r4,1
stb r8,0x0(r3)
addi r3,r3,1
bdnz L(unaligned_bytecopy_loop)
srwi. r7,r5,5
beq L(preword2_count_loop)
mtctr r7
L(word8_count_loop_no_dcbt): /* Copy 32 bytes at a time */
lwz r6,0(r4)
lwz r7,4(r4)
lwz r8,8(r4)
lwz r9,12(r4)
subi r5,r5,0x20
stw r6,0(r3)
stw r7,4(r3)
stw r8,8(r3)
stw r9,12(r3)
lwz r6,16(r4)
lwz r7,20(r4)
lwz r8,24(r4)
lwz r9,28(r4)
addi r4,r4,0x20
stw r6,16(r3)
stw r7,20(r3)
stw r8,24(r3)
stw r9,28(r3)
addi r3,r3,0x20
bdnz L(word8_count_loop_no_dcbt)
L(preword2_count_loop): /* Copy remaining 0-31 bytes */
clrlwi. r12,r5,27
beq L(end_memcpy)
mtxer r12
lswx r5,0,r4
stswx r5,0,r3
mr r3,r0
blr
L(string_count_loop): /* Copy odd 0-31 bytes */
clrlwi. r12,r5,28
add r3,r3,r5
add r4,r4,r5
beq L(pre_string_copy)
mtxer r12
subf r4,r12,r4
subf r3,r12,r3
lswx r6,0,r4
stswx r6,0,r3
L(pre_string_copy): /* Check how many 32 byte chunck to copy */
srwi. r7,r5,4
beq L(end_memcpy)
mtctr r7
L(word4_count_loop_no_dcbt): /* Copy 32 bytes at a time */
lwz r6,-4(r4)
lwz r7,-8(r4)
lwz r8,-12(r4)
lwzu r9,-16(r4)
stw r6,-4(r3)
stw r7,-8(r3)
stw r8,-12(r3)
stwu r9,-16(r3)
bdz L(end_memcpy)
lwz r6,-4(r4)
lwz r7,-8(r4)
lwz r8,-12(r4)
lwzu r9,-16(r4)
stw r6,-4(r3)
stw r7,-8(r3)
stw r8,-12(r3)
stwu r9,-16(r3)
bdnz L(word4_count_loop_no_dcbt)
L(end_memcpy):
mr r3,r0
blr
END (BP_SYM (memcpy))
libc_hidden_builtin_def (memcpy)
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