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4f26956d5b
This patch optimizes the performance of memset 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 prefetch. SVE assembler code for memset 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>
57 lines
2.0 KiB
C
57 lines
2.0 KiB
C
/* Multiple versions of memset. AARCH64 version.
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Copyright (C) 2017-2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* Define multiple versions only for the definition in libc. */
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#if IS_IN (libc)
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/* Redefine memset so that the compiler won't complain about the type
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mismatch with the IFUNC selector in strong_alias, below. */
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# undef memset
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# define memset __redirect_memset
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# include <string.h>
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# include <init-arch.h>
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extern __typeof (__redirect_memset) __libc_memset;
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extern __typeof (__redirect_memset) __memset_falkor attribute_hidden;
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extern __typeof (__redirect_memset) __memset_emag attribute_hidden;
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extern __typeof (__redirect_memset) __memset_kunpeng attribute_hidden;
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# if HAVE_AARCH64_SVE_ASM
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extern __typeof (__redirect_memset) __memset_a64fx attribute_hidden;
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# endif
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extern __typeof (__redirect_memset) __memset_generic attribute_hidden;
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libc_ifunc (__libc_memset,
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IS_KUNPENG920 (midr)
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?__memset_kunpeng
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: ((IS_FALKOR (midr) || IS_PHECDA (midr)) && zva_size == 64
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? __memset_falkor
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: (IS_EMAG (midr) && zva_size == 64
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? __memset_emag
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# if HAVE_AARCH64_SVE_ASM
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: (IS_A64FX (midr)
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? __memset_a64fx
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: __memset_generic))));
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# else
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: __memset_generic)));
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# endif
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# undef memset
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strong_alias (__libc_memset, memset);
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#endif
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