mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 23:10:06 +00:00
7ebba91361
Since VZEROUPPER triggers RTM abort while VZEROALL won't, select AVX optimized string/memory functions with xtest jz 1f vzeroall ret 1: vzeroupper ret at function exit on processors with usable RTM, but without 256-bit EVEX instructions to avoid VZEROUPPER inside a transactionally executing RTM region.
74 lines
2.6 KiB
C
74 lines
2.6 KiB
C
/* Multiple versions of strncmp.
|
|
All versions must be listed in ifunc-impl-list.c.
|
|
Copyright (C) 2017-2021 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
/* Define multiple versions only for the definition in libc. */
|
|
#if IS_IN (libc)
|
|
# define strncmp __redirect_strncmp
|
|
# include <string.h>
|
|
# undef strncmp
|
|
|
|
# define SYMBOL_NAME strncmp
|
|
# include <init-arch.h>
|
|
|
|
extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
|
|
extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
|
|
extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;
|
|
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
|
|
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
|
|
extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
|
|
|
|
static inline void *
|
|
IFUNC_SELECTOR (void)
|
|
{
|
|
const struct cpu_features* cpu_features = __get_cpu_features ();
|
|
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
|
|
&& CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
|
|
{
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
|
|
&& CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
|
|
&& CPU_FEATURE_USABLE_P (cpu_features, BMI2)
|
|
&& !CPU_FEATURES_ARCH_P (cpu_features, Prefer_AVX2_STRCMP))
|
|
return OPTIMIZE (evex);
|
|
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
|
|
return OPTIMIZE (avx2_rtm);
|
|
|
|
if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
|
|
return OPTIMIZE (avx2);
|
|
}
|
|
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)
|
|
&& !CPU_FEATURES_ARCH_P (cpu_features, Slow_SSE4_2))
|
|
return OPTIMIZE (sse42);
|
|
|
|
if (CPU_FEATURE_USABLE_P (cpu_features, SSSE3))
|
|
return OPTIMIZE (ssse3);
|
|
|
|
return OPTIMIZE (sse2);
|
|
}
|
|
|
|
libc_ifunc_redirected (__redirect_strncmp, strncmp, IFUNC_SELECTOR ());
|
|
|
|
# ifdef SHARED
|
|
__hidden_ver1 (strncmp, __GI_strncmp, __redirect_strncmp)
|
|
__attribute__ ((visibility ("hidden"))) __attribute_copy__ (strncmp);
|
|
# endif
|
|
#endif
|