1#ifndef _LINUX_HELPER_MACROS_H_
2#define _LINUX_HELPER_MACROS_H_
3
4#define __find_closest(x, a, as, op)					\
5({									\
6	typeof(as) __fc_i, __fc_as = (as) - 1;				\
7	typeof(x) __fc_x = (x);						\
8	typeof(*a) const *__fc_a = (a);					\
9	for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) {			\
10		if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] +	\
11						__fc_a[__fc_i + 1], 2))	\
12			break;						\
13	}								\
14	(__fc_i);							\
15})
16
17/**
18 * find_closest - locate the closest element in a sorted array
19 * @x: The reference value.
20 * @a: The array in which to look for the closest element. Must be sorted
21 *  in ascending order.
22 * @as: Size of 'a'.
23 *
24 * Returns the index of the element closest to 'x'.
25 */
26#define find_closest(x, a, as) __find_closest(x, a, as, <=)
27
28/**
29 * find_closest_descending - locate the closest element in a sorted array
30 * @x: The reference value.
31 * @a: The array in which to look for the closest element. Must be sorted
32 *  in descending order.
33 * @as: Size of 'a'.
34 *
35 * Similar to find_closest() but 'a' is expected to be sorted in descending
36 * order.
37 */
38#define find_closest_descending(x, a, as) __find_closest(x, a, as, >=)
39
40#endif
41