glibc/sysdeps/x86_64/multiarch/strstr.c

67 lines
2.3 KiB
C

/* Multiple versions of strstr.
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2012-2023 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/>. */
/* Redefine strstr so that the compiler won't complain about the type
mismatch with the IFUNC selector in strong_alias, below. */
#undef strstr
#define strstr __redirect_strstr
#include <string.h>
#undef strstr
#define STRSTR __strstr_generic
#ifdef SHARED
# undef libc_hidden_builtin_def
# define libc_hidden_builtin_def(name) \
__hidden_ver1 (__strstr_generic, __GI_strstr, __strstr_generic);
#endif
#include "string/strstr.c"
extern __typeof (__redirect_strstr) __strstr_sse2_unaligned attribute_hidden;
extern __typeof (__redirect_strstr) __strstr_generic attribute_hidden;
extern __typeof (__redirect_strstr) __strstr_avx512 attribute_hidden;
#include "init-arch.h"
/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
ifunc symbol properly. */
extern __typeof (__redirect_strstr) __libc_strstr;
static inline void *
IFUNC_SELECTOR (void)
{
const struct cpu_features *cpu_features = __get_cpu_features ();
if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512)
&& CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
&& CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
&& CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
&& CPU_FEATURE_USABLE_P (cpu_features, BMI2))
return __strstr_avx512;
if (CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Load))
return __strstr_sse2_unaligned;
return __strstr_generic;
}
libc_ifunc_redirected (__redirect_strstr, __libc_strstr, IFUNC_SELECTOR ());
#undef strstr
strong_alias (__libc_strstr, strstr)