1  /* Multiple versions of strstr.
       2     All versions must be listed in ifunc-impl-list.c.
       3     Copyright (C) 2012-2023 Free Software Foundation, Inc.
       4     This file is part of the GNU C Library.
       5  
       6     The GNU C Library is free software; you can redistribute it and/or
       7     modify it under the terms of the GNU Lesser General Public
       8     License as published by the Free Software Foundation; either
       9     version 2.1 of the License, or (at your option) any later version.
      10  
      11     The GNU C Library is distributed in the hope that it will be useful,
      12     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14     Lesser General Public License for more details.
      15  
      16     You should have received a copy of the GNU Lesser General Public
      17     License along with the GNU C Library; if not, see
      18     <https://www.gnu.org/licenses/>.  */
      19  
      20  /* Redefine strstr so that the compiler won't complain about the type
      21     mismatch with the IFUNC selector in strong_alias, below.  */
      22  #undef  strstr
      23  #define strstr __redirect_strstr
      24  #include <string.h>
      25  #undef  strstr
      26  
      27  #define STRSTR __strstr_generic
      28  #ifdef SHARED
      29  # undef libc_hidden_builtin_def
      30  # define libc_hidden_builtin_def(name) \
      31    __hidden_ver1 (__strstr_generic, __GI_strstr, __strstr_generic);
      32  #endif
      33  
      34  #include "string/strstr.c"
      35  
      36  extern __typeof (__redirect_strstr) __strstr_sse2_unaligned attribute_hidden;
      37  extern __typeof (__redirect_strstr) __strstr_generic attribute_hidden;
      38  extern __typeof (__redirect_strstr) __strstr_avx512 attribute_hidden;
      39  
      40  #include "init-arch.h"
      41  
      42  /* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
      43     ifunc symbol properly.  */
      44  extern __typeof (__redirect_strstr) __libc_strstr;
      45  
      46  static inline void *
      47  IFUNC_SELECTOR (void)
      48  {
      49    const struct cpu_features *cpu_features = __get_cpu_features ();
      50  
      51    if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512)
      52        && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
      53        && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
      54        && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
      55        && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
      56      return __strstr_avx512;
      57  
      58    if (CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Load))
      59      return __strstr_sse2_unaligned;
      60  
      61    return __strstr_generic;
      62  }
      63  
      64  libc_ifunc_redirected (__redirect_strstr, __libc_strstr, IFUNC_SELECTOR ());
      65  #undef strstr
      66  strong_alias (__libc_strstr, strstr)