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96d6fd6c40
This patch adds an optimized POWER8 strcpy using unaligned accesses. For strings up to 16 bytes the implementation first calculate the string size, like strlen, and issues a memcpy. For larger strings, source is first aligned to 16 bytes and then tested over a loop that reads 16 bytes am combine the cmpb results for speedup. Special case is added for page cross reads. It shows 30%-60% improvement over the optimized POWER7 one that uses only aligned accesses.
35 lines
1.3 KiB
C
35 lines
1.3 KiB
C
/* Multiple versions of strcpy. PowerPC64 version.
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Copyright (C) 2013-2015 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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#if defined SHARED && IS_IN (libc)
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# include <string.h>
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# include <shlib-compat.h>
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# include "init-arch.h"
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extern __typeof (strcpy) __strcpy_ppc attribute_hidden;
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extern __typeof (strcpy) __strcpy_power7 attribute_hidden;
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extern __typeof (strcpy) __strcpy_power8 attribute_hidden;
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libc_ifunc (strcpy,
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(hwcap2 & PPC_FEATURE2_ARCH_2_07)
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? __strcpy_power8 :
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(hwcap & PPC_FEATURE_HAS_VSX)
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? __strcpy_power7
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: __strcpy_ppc);
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#endif
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