glibc/sysdeps/powerpc/powerpc64/multiarch/memcpy.c
Tulio Magno Quites Machado Filho e941e0ae80 powerpc64le: Optimize memcpy for POWER10
This implementation is based on __memcpy_power8_cached and integrates
suggestions from Anton Blanchard.
It benefits from loads and stores with length for short lengths and for
tail code, simplifying the code.

All unaligned memory accesses use instructions that do not generate
alignment interrupts on POWER10, making it safe to use on
caching-inhibited memory.

The main loop has also been modified in order to increase instruction
throughput by reducing the dependency on updates from previous iterations.

On average, this implementation provides around 30% improvement when
compared to __memcpy_power7 and 10% improvement in comparison to
__memcpy_power8_cached.
2021-04-30 18:12:08 -03:00

66 lines
2.5 KiB
C

/* Multiple versions of memcpy. PowerPC64 version.
Copyright (C) 2013-2021 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 lib and for
DSO. In static binaries we need memcpy before the initialization
happened. */
#if defined SHARED && 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_ppc attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_power4 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_cell attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_power6 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_a2 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_power7 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_power8_cached attribute_hidden;
# if defined __LITTLE_ENDIAN__
extern __typeof (__redirect_memcpy) __memcpy_power10 attribute_hidden;
# endif
libc_ifunc (__libc_memcpy,
# if defined __LITTLE_ENDIAN__
(hwcap2 & PPC_FEATURE2_ARCH_3_1 && hwcap & PPC_FEATURE_HAS_VSX)
? __memcpy_power10 :
# endif
((hwcap2 & PPC_FEATURE2_ARCH_2_07) && use_cached_memopt)
? __memcpy_power8_cached :
(hwcap & PPC_FEATURE_HAS_VSX)
? __memcpy_power7 :
(hwcap & PPC_FEATURE_ARCH_2_06)
? __memcpy_a2 :
(hwcap & PPC_FEATURE_ARCH_2_05)
? __memcpy_power6 :
(hwcap & PPC_FEATURE_CELL_BE)
? __memcpy_cell :
(hwcap & PPC_FEATURE_POWER4)
? __memcpy_power4
: __memcpy_ppc);
#undef memcpy
strong_alias (__libc_memcpy, memcpy);
libc_hidden_ver (__libc_memcpy, memcpy);
#endif