[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / asm-generic / bitops / ffs.h

#ifndef _ASM_GENERIC_BITOPS_FFS_H_
#define _ASM_GENERIC_BITOPS_FFS_H_

/**
 * ffs - find first bit set
 * @x: the word to search
 *
 * This is defined the same way as
 * the libc and compiler builtin ffs routines, therefore
 * differs in spirit from the above ffz (man ffs).
 */
static inline int ffs(int x)
{
	int r = 1;

	if (!x)
		return 0;
	if (!(x & 0xffff)) {
		x >>= 16;
		r += 16;
	}
	if (!(x & 0xff)) {
		x >>= 8;
		r += 8;
	}
	if (!(x & 0xf)) {
		x >>= 4;
		r += 4;
	}
	if (!(x & 3)) {
		x >>= 2;
		r += 2;
	}
	if (!(x & 1)) {
		x >>= 1;
		r += 1;
	}
	return r;
}

#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */
Commit	Line	Data
09020adb AM	1	#ifndef _ASM_GENERIC_BITOPS_FFS_H_
	2	#define _ASM_GENERIC_BITOPS_FFS_H_
	3
	4	/**
	5	* ffs - find first bit set
	6	* @x: the word to search
	7	*
	8	* This is defined the same way as
	9	* the libc and compiler builtin ffs routines, therefore
	10	* differs in spirit from the above ffz (man ffs).
	11	*/
	12	static inline int ffs(int x)
	13	{
	14	int r = 1;
	15
	16	if (!x)
	17	return 0;
	18	if (!(x & 0xffff)) {
	19	x >>= 16;
	20	r += 16;
	21	}
	22	if (!(x & 0xff)) {
	23	x >>= 8;
	24	r += 8;
	25	}
	26	if (!(x & 0xf)) {
	27	x >>= 4;
	28	r += 4;
	29	}
	30	if (!(x & 3)) {
	31	x >>= 2;
	32	r += 2;
	33	}
	34	if (!(x & 1)) {
	35	x >>= 1;
	36	r += 1;
	37	}
	38	return r;
	39	}
	40
	41	#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */