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05f3633da4
In this patch we take advantage of HSW memory bandwidth, manage to reduce miss branch prediction by avoiding using branch instructions and force destination to be aligned with avx instruction. The CPU2006 403.gcc benchmark indicates this patch improves performance from 2% to 10%.
65 lines
2.2 KiB
C
65 lines
2.2 KiB
C
/* Multiple versions of memmove.
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All versions must be listed in ifunc-impl-list.c.
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Copyright (C) 2010-2014 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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<http://www.gnu.org/licenses/>. */
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#ifndef NOT_IN_libc
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# define MEMMOVE __memmove_sse2
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# ifdef SHARED
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# undef libc_hidden_builtin_def
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# define libc_hidden_builtin_def(name) \
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__hidden_ver1 (__memmove_sse2, __GI_memmove, __memmove_sse2);
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# endif
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/* Redefine memmove 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 memmove
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# define memmove __redirect_memmove
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# include <string.h>
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# undef memmove
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extern __typeof (__redirect_memmove) __memmove_sse2 attribute_hidden;
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extern __typeof (__redirect_memmove) __memmove_ssse3 attribute_hidden;
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extern __typeof (__redirect_memmove) __memmove_ssse3_back attribute_hidden;
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extern __typeof (__redirect_memmove) __memmove_avx_unaligned attribute_hidden;
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#endif
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#include "string/memmove.c"
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#ifndef NOT_IN_libc
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# include <shlib-compat.h>
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# include "init-arch.h"
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/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
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ifunc symbol properly. */
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extern __typeof (__redirect_memmove) __libc_memmove;
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libc_ifunc (__libc_memmove,
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HAS_AVX
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? __memmove_avx_unaligned
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: (HAS_SSSE3
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? (HAS_FAST_COPY_BACKWARD
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? __memmove_ssse3_back : __memmove_ssse3)
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: __memmove_sse2));
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strong_alias (__libc_memmove, memmove)
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# if SHLIB_COMPAT (libc, GLIBC_2_2_5, GLIBC_2_14)
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compat_symbol (libc, memmove, memcpy, GLIBC_2_2_5);
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# endif
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#endif
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