glibc/sysdeps/aarch64/multiarch/memset_falkor.S

55 lines
1.7 KiB
ArmAsm

/* Memset for falkor.
Copyright (C) 2017-2023 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>
#include <memset-reg.h>
/* Reading dczid_el0 is expensive on falkor so move it into the ifunc
resolver and assume ZVA size of 64 bytes. The IFUNC resolver takes care to
use this function only when ZVA is enabled. */
#if IS_IN (libc)
.macro zva_macro
.p2align 4
/* Write the first and last 64 byte aligned block using stp rather
than using DC ZVA. This is faster on some cores. */
str q0, [dst, 16]
stp q0, q0, [dst, 32]
bic dst, dst, 63
stp q0, q0, [dst, 64]
stp q0, q0, [dst, 96]
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 q0, q0, [dst, 0]
stp q0, q0, [dst, 32]
stp q0, q0, [dstend, -64]
stp q0, q0, [dstend, -32]
ret
.endm
# define ZVA_MACRO zva_macro
# define MEMSET __memset_falkor
# include <sysdeps/aarch64/memset.S>
#endif