#include <isl_config.h>

#if !HAVE_DECL_FFS && !HAVE_DECL___BUILTIN_FFS && HAVE_DECL__BITSCANFORWARD

#include <intrin.h>

/* Implementation of ffs in terms of _BitScanForward.

 *

 * ffs returns the position of the least significant bit set in i,

 * with the least significant bit is position 1, or 0 if not bits are set.

 *

 * _BitScanForward returns 1 if mask is non-zero and sets index

 * to the position of the least significant bit set in i,

 * with the least significant bit is position 0.

 */

int isl_ffs(int i)

{

	unsigned char non_zero;

	unsigned long index, mask = i;

	non_zero = _BitScanForward(&index, mask);

	return non_zero ? 1 + index : 0;

}

#endif