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/* Optimized memset for PowerPC476 (128-byte cacheline).
Copyright (C) 2010-2024 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>
/* memset
r3:destination address and return address
r4:source integer to copy
r5:byte count
r11:sources integer to copy in all 32 bits of reg
r12:temp return address
Save return address in r12
If destination is unaligned and count is greater than 255 bytes
set 0-3 bytes to make destination aligned
If count is greater than 255 bytes and setting zero to memory
use dbcz to set memory when we can
otherwise do the following
If 16 or more words to set we use 16 word copy loop.
Finally we set 0-15 extra bytes with string store. */
EALIGN (memset, 5, 0)
rlwinm r11,r4,0,24,31
rlwimi r11,r4,8,16,23
rlwimi r11,r11,16,0,15
addi r12,r3,0
cmpwi r5,0x00FF
ble L(preword8_count_loop)
cmpwi r4,0x00
beq L(use_dcbz)
neg r6,r3
clrlwi. r6,r6,30
beq L(preword8_count_loop)
addi r8,0,1
mtctr r6
subi r3,r3,1
L(unaligned_bytecopy_loop):
stbu r11,0x1(r3)
subf. r5,r8,r5
beq L(end_memset)
bdnz L(unaligned_bytecopy_loop)
addi r3,r3,1
L(preword8_count_loop):
srwi. r6,r5,4
beq L(preword2_count_loop)
mtctr r6
addi r3,r3,-4
mr r8,r11
mr r9,r11
mr r10,r11
L(word8_count_loop_no_dcbt):
stwu r8,4(r3)
stwu r9,4(r3)
subi r5,r5,0x10
stwu r10,4(r3)
stwu r11,4(r3)
bdnz L(word8_count_loop_no_dcbt)
addi r3,r3,4
L(preword2_count_loop):
clrlwi. r7,r5,28
beq L(end_memset)
mr r8,r11
mr r9,r11
mr r10,r11
mtxer r7
stswx r8,0,r3
L(end_memset):
addi r3,r12,0
blr
L(use_dcbz):
neg r6,r3
clrlwi. r7,r6,28
beq L(skip_string_loop)
mr r8,r11
mr r9,r11
mr r10,r11
subf r5,r7,r5
mtxer r7
stswx r8,0,r3
add r3,r3,r7
L(skip_string_loop):
clrlwi r8,r6,25
srwi. r8,r8,4
beq L(dcbz_pre_loop)
mtctr r8
L(word_loop):
stw r11,0(r3)
subi r5,r5,0x10
stw r11,4(r3)
stw r11,8(r3)
stw r11,12(r3)
addi r3,r3,0x10
bdnz L(word_loop)
L(dcbz_pre_loop):
srwi r6,r5,7
mtctr r6
addi r7,0,0
L(dcbz_loop):
dcbz r3,r7
addi r3,r3,0x80
subi r5,r5,0x80
bdnz L(dcbz_loop)
srwi. r6,r5,4
beq L(postword2_count_loop)
mtctr r6
L(postword8_count_loop):
stw r11,0(r3)
subi r5,r5,0x10
stw r11,4(r3)
stw r11,8(r3)
stw r11,12(r3)
addi r3,r3,0x10
bdnz L(postword8_count_loop)
L(postword2_count_loop):
clrlwi. r7,r5,28
beq L(end_memset)
mr r8,r11
mr r9,r11
mr r10,r11
mtxer r7
stswx r8,0,r3
b L(end_memset)
END (memset)
libc_hidden_builtin_def (memset)
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