sysdeps/unix/sysv/linux/riscv/multiarch/memcpy.c

   1 /* Multiple versions of memcpy.
   2    All versions must be listed in ifunc-impl-list.c.
   3    Copyright (C) 2017-2024 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 #if IS_IN (libc)
  21 /* Redefine memcpy so that the compiler won't complain about the type
  22    mismatch with the IFUNC selector in strong_alias, below.  */
  23 # undef memcpy
  24 # define memcpy __redirect_memcpy
  25 # include <stdint.h>
  26 # include <string.h>
  27 # include <ifunc-init.h>
  28 # include <riscv-ifunc.h>
  29 # include <sys/hwprobe.h>
  30
  31 extern __typeof (__redirect_memcpy) __libc_memcpy;
  32
  33 extern __typeof (__redirect_memcpy) __memcpy_generic attribute_hidden;
  34 extern __typeof (__redirect_memcpy) __memcpy_noalignment attribute_hidden;
  35
  36 static inline __typeof (__redirect_memcpy) *
  37 select_memcpy_ifunc (uint64_t dl_hwcap, __riscv_hwprobe_t hwprobe_func)
  38 {
  39   unsigned long long int v;
  40   if (__riscv_hwprobe_one (hwprobe_func, RISCV_HWPROBE_KEY_CPUPERF_0, &v) == 0
  41       && (v & RISCV_HWPROBE_MISALIGNED_MASK) == RISCV_HWPROBE_MISALIGNED_FAST)
  42     return __memcpy_noalignment;
  43
  44   return __memcpy_generic;
  45 }
  46
  47 riscv_libc_ifunc (__libc_memcpy, select_memcpy_ifunc);
  48
  49 # undef memcpy
  50 strong_alias (__libc_memcpy, memcpy);
  51 # ifdef SHARED
  52 __hidden_ver1 (memcpy, __GI_memcpy, __redirect_memcpy)
  53   __attribute__ ((visibility ("hidden"))) __attribute_copy__ (memcpy);
  54 # endif
  55 #else
  56 # include <string/memcpy.c>
  57 #endif