glibc/sysdeps/aarch64/multiarch/memcpy.c
Naohiro Tamura fa527f345c aarch64: Added optimized memcpy and memmove for A64FX
This patch optimizes the performance of memcpy/memmove for A64FX [1]
which implements ARMv8-A SVE and has L1 64KB cache per core and L2 8MB
cache per NUMA node.

The performance optimization makes use of Scalable Vector Register
with several techniques such as loop unrolling, memory access
alignment, cache zero fill, and software pipelining.

SVE assembler code for memcpy/memmove is implemented as Vector Length
Agnostic code so theoretically it can be run on any SOC which supports
ARMv8-A SVE standard.

We confirmed that all testcases have been passed by running 'make
check' and 'make xcheck' not only on A64FX but also on ThunderX2.

And also we confirmed that the SVE 512 bit vector register performance
is roughly 4 times better than Advanced SIMD 128 bit register and 8
times better than scalar 64 bit register by running 'make bench'.

[1] https://github.com/fujitsu/A64FX

Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Reviewed-by: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
2021-05-27 09:47:53 +01:00

60 lines
2.2 KiB
C

/* Multiple versions of memcpy. AARCH64 version.
Copyright (C) 2017-2021 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/>. */
/* Define multiple versions only for the definition in libc. */
#if IS_IN (libc)
/* Redefine memcpy so that the compiler won't complain about the type
mismatch with the IFUNC selector in strong_alias, below. */
# undef memcpy
# define memcpy __redirect_memcpy
# include <string.h>
# include <init-arch.h>
extern __typeof (__redirect_memcpy) __libc_memcpy;
extern __typeof (__redirect_memcpy) __memcpy_generic attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_simd attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_thunderx attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_thunderx2 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_falkor attribute_hidden;
# if HAVE_AARCH64_SVE_ASM
extern __typeof (__redirect_memcpy) __memcpy_a64fx attribute_hidden;
# endif
libc_ifunc (__libc_memcpy,
(IS_THUNDERX (midr)
? __memcpy_thunderx
: (IS_FALKOR (midr) || IS_PHECDA (midr)
? __memcpy_falkor
: (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
? __memcpy_thunderx2
: (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
|| IS_NEOVERSE_V1 (midr)
? __memcpy_simd
# if HAVE_AARCH64_SVE_ASM
: (IS_A64FX (midr)
? __memcpy_a64fx
: __memcpy_generic))))));
# else
: __memcpy_generic)))));
# endif
# undef memcpy
strong_alias (__libc_memcpy, memcpy);
#endif