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/* Optimized memset for Qualcomm's oyron-1 core.
Copyright (C) 2018-2024 Free Software Foundation, Inc.
Copyright The GNU Toolchain Authors.
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>
/* Assumptions:
ARMv8-a, AArch64, unaligned accesses
*/
#define dstin x0
#define val x1
#define valw w1
#define count x2
#define dst x3
#define dstend x4
ENTRY (__memset_oryon1)
PTR_ARG (0)
SIZE_ARG (2)
bfi valw, valw, 8, 8
bfi valw, valw, 16, 16
bfi val, val, 32, 32
add dstend, dstin, count
cmp count, 96
b.hi L(set_long)
cmp count, 16
b.hs L(set_medium)
/* Set 0..15 bytes. */
tbz count, 3, 1f
str val, [dstin]
str val, [dstend, -8]
ret
.p2align 3
1: tbz count, 2, 2f
str valw, [dstin]
str valw, [dstend, -4]
ret
2: cbz count, 3f
strb valw, [dstin]
tbz count, 1, 3f
strh valw, [dstend, -2]
3: ret
.p2align 3
/* Set 16..96 bytes. */
L(set_medium):
stp val, val, [dstin]
tbnz count, 6, L(set96)
stp val, val, [dstend, -16]
tbz count, 5, 1f
stp val, val, [dstin, 16]
stp val, val, [dstend, -32]
1: ret
.p2align 6
/* Set 64..96 bytes. Write 64 bytes from the start and
32 bytes from the end. */
L(set96):
stp val, val, [dstin, 16]
stp val, val, [dstin, 32]
stp val, val, [dstin, 48]
stp val, val, [dstend, -32]
stp val, val, [dstend, -16]
ret
.p2align 6
L(set_long):
stp val, val, [dstin]
bic dst, dstin, 15
cmp count, 256
ccmp valw, 0, 0, cs
b.eq L(try_zva)
cmp count, #32768
b.hi L(set_long_with_nontemp)
/* Small-size or non-zero memset does not use DC ZVA. */
sub count, dstend, dst
/* Adjust count and bias for loop. By subtracting extra 1 from count,
it is easy to use tbz instruction to check whether loop tailing
count is less than 33 bytes, so as to bypass 2 unnecessary stps. */
sub count, count, 64+16+1
1: stp val, val, [dst, 16]
stp val, val, [dst, 32]
stp val, val, [dst, 48]
stp val, val, [dst, 64]!
subs count, count, 64
b.hs 1b
tbz count, 5, 1f /* Remaining count is less than 33 bytes? */
stp val, val, [dst, 16]
stp val, val, [dst, 32]
1: stp val, val, [dstend, -32]
stp val, val, [dstend, -16]
ret
L(set_long_with_nontemp):
/* Small-size or non-zero memset does not use DC ZVA. */
sub count, dstend, dst
/* Adjust count and bias for loop. By subtracting extra 1 from count,
it is easy to use tbz instruction to check whether loop tailing
count is less than 33 bytes, so as to bypass 2 unnecessary stps. */
sub count, count, 64+16+1
1: stnp val, val, [dst, 16]
stnp val, val, [dst, 32]
stnp val, val, [dst, 48]
stnp val, val, [dst, 64]
add dst, dst, #64
subs count, count, 64
b.hs 1b
tbz count, 5, 1f /* Remaining count is less than 33 bytes? */
stnp val, val, [dst, 16]
stnp val, val, [dst, 32]
1: stnp val, val, [dstend, -32]
stnp val, val, [dstend, -16]
ret
L(try_zva):
/* Write the first and last 64 byte aligned block using stp rather
than using DC ZVA as it is faster. */
.p2align 6
L(zva_64):
stp val, val, [dst, 16]
stp val, val, [dst, 32]
stp val, val, [dst, 48]
bic dst, dst, 63
stp val, val, [dst, 64]
stp val, val, [dst, 64+16]
stp val, val, [dst, 96]
stp val, val, [dst, 96+16]
sub count, dstend, dst /* Count is now 128 too large. */
sub count, count, 128+64+64 /* Adjust count and bias for loop. */
add dst, dst, 128
1: dc zva, dst
add dst, dst, 64
subs count, count, 64
b.hi 1b
stp val, val, [dst, 0]
stp val, val, [dst, 16]
stp val, val, [dst, 32]
stp val, val, [dst, 48]
stp val, val, [dstend, -64]
stp val, val, [dstend, -64+16]
stp val, val, [dstend, -32]
stp val, val, [dstend, -16]
ret
END (__memset_oryon1)
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