glibc/string/ffsll.c

41 lines
1.2 KiB
C

/* Copyright (C) 1991-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Torbjorn Granlund (tege@sics.se).
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/>. */
#include <limits.h>
#define ffsl __something_else
#include <string.h>
#undef ffsll
/* Find the first bit set in I. */
int
ffsll (long long int i)
{
unsigned long long int x = i & -i;
if (x <= 0xffffffff)
return ffs (i);
else
return 32 + ffs (i >> 32);
}
#if ULONG_MAX != UINT_MAX
#undef ffsl
weak_alias (ffsll, ffsl)
#endif