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d3b00f468b
This patch adds an optimized POWER8 strncmp. The implementation focus on speeding up unaligned cases follwing the ideas of power8 strcmp. The algorithm first check the initial 16 bytes, then align the first function source and uses unaligned loads on second argument only. Aditional checks for page boundaries are done for unaligned cases (where sources alignment are different).
41 lines
1.6 KiB
C
41 lines
1.6 KiB
C
/* Multiple versions of strncmp.
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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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/* Define multiple versions only for definition in libc. */
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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 (strncmp) __strncmp_ppc attribute_hidden;
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extern __typeof (strncmp) __strncmp_power4 attribute_hidden;
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extern __typeof (strncmp) __strncmp_power7 attribute_hidden;
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extern __typeof (strncmp) __strncmp_power8 attribute_hidden;
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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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libc_ifunc (strncmp,
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(hwcap2 & PPC_FEATURE2_ARCH_2_07)
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? __strncmp_power8 :
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(hwcap & PPC_FEATURE_HAS_VSX)
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? __strncmp_power7 :
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(hwcap & PPC_FEATURE_POWER4)
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? __strncmp_power4
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: __strncmp_ppc);
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#endif
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