string/ffsll.c

   1 /* Copyright (C) 1991-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <limits.h>
  19 #define ffsl __something_else
  20 #include <string.h>
  21
  22 #undef  ffsll
  23
  24 /* Find the first bit set in I.  */
  25 int
  26 ffsll (long long int i)
  27 {
  28   unsigned long long int x = i & -i;
  29
  30   if (x <= 0xffffffff)
  31     return ffs (i);
  32   else
  33     return 32 + ffs (i >> 32);
  34 }
  35
  36 #if ULONG_MAX != UINT_MAX
  37 #undef ffsl
  38 weak_alias (ffsll, ffsl)
  39 #endif