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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%.
51 lines
1.7 KiB
ArmAsm
51 lines
1.7 KiB
ArmAsm
/* Multiple versions of __memcpy_chk
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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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Contributed by Intel Corporation.
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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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#include <sysdep.h>
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#include <init-arch.h>
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/* Define multiple versions only for the definition in lib and for
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DSO. There are no multiarch memcpy functions for static binaries.
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*/
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#ifndef NOT_IN_libc
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# ifdef SHARED
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.text
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ENTRY(__memcpy_chk)
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.type __memcpy_chk, @gnu_indirect_function
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cmpl $0, KIND_OFFSET+__cpu_features(%rip)
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jne 1f
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call __init_cpu_features
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1: leaq __memcpy_chk_sse2(%rip), %rax
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testl $bit_SSSE3, __cpu_features+CPUID_OFFSET+index_SSSE3(%rip)
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jz 2f
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leaq __memcpy_chk_ssse3(%rip), %rax
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testl $bit_Fast_Copy_Backward, __cpu_features+FEATURE_OFFSET+index_Fast_Copy_Backward(%rip)
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jz 2f
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leaq __memcpy_chk_ssse3_back(%rip), %rax
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testl $bit_AVX_Usable, __cpu_features+FEATURE_OFFSET+index_AVX_Usable(%rip)
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jz 2f
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leaq __memcpy_chk_avx_unaligned(%rip), %rax
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2: ret
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END(__memcpy_chk)
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# else
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# include "../memcpy_chk.S"
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# endif
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#endif
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