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17762f6625
This patch adds an optimized memmove optimization for POWER7/powerpc64. Basically the idea is to use the memcpy for POWER7 on non-overlapped memory regions and a optimized backward memcpy for memory regions that overlap (similar to the idea of string/memmove.c). The backward memcpy algorithm used is similar the one use for memcpy for POWER7, with adjustments done for alignment. The difference is memory is always aligned to 16 bytes before using VSX/altivec instructions.
46 lines
1.7 KiB
C
46 lines
1.7 KiB
C
/* Multiple versions of memmove. PowerPC64 version.
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Copyright (C) 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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/* Define multiple versions only for the definition in lib and for
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DSO. In static binaries we need memmove before the initialization
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happened. */
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#if defined SHARED && !defined NOT_IN_libc
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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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# include "init-arch.h"
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extern __typeof (__redirect_memmove) __libc_memmove;
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extern __typeof (__redirect_memmove) __memmove_ppc attribute_hidden;
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extern __typeof (__redirect_memmove) __memmove_power7 attribute_hidden;
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libc_ifunc (__libc_memmove,
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(hwcap & PPC_FEATURE_HAS_VSX)
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? __memmove_power7
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: __memmove_ppc);
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#undef memmove
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strong_alias (__libc_memmove, memmove);
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libc_hidden_ver (__libc_memmove, memmove);
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#else
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# include <string/memmove.c>
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#endif
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