llvm-project/compiler-rt/lib/builtins/ffssi2.c

30 lines
793 B
C

/* ===-- ffssi2.c - Implement __ffssi2 -------------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __ffssi2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: the index of the least significant 1-bit in a, or
* the value zero if a is zero. The least significant bit is index one.
*/
COMPILER_RT_ABI si_int
__ffssi2(si_int a)
{
if (a == 0)
{
return 0;
}
return __builtin_ctz(a) + 1;
}