1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _LINUX_HELPER_MACROS_H_
 3#define _LINUX_HELPER_MACROS_H_
 4
 5#define __find_closest(x, a, as, op)					\
 6({									\
 7	typeof(as) __fc_i, __fc_as = (as) - 1;				\
 8	typeof(x) __fc_x = (x);						\
 9	typeof(*a) const *__fc_a = (a);					\
10	for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) {			\
11		if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] +	\
12						__fc_a[__fc_i + 1], 2))	\
13			break;						\
14	}								\
15	(__fc_i);							\
16})
17
18/**
19 * find_closest - locate the closest element in a sorted array
20 * @x: The reference value.
21 * @a: The array in which to look for the closest element. Must be sorted
22 *  in ascending order.
23 * @as: Size of 'a'.
24 *
25 * Returns the index of the element closest to 'x'.
26 */
27#define find_closest(x, a, as) __find_closest(x, a, as, <=)
28
29/**
30 * find_closest_descending - locate the closest element in a sorted array
31 * @x: The reference value.
32 * @a: The array in which to look for the closest element. Must be sorted
33 *  in descending order.
34 * @as: Size of 'a'.
35 *
36 * Similar to find_closest() but 'a' is expected to be sorted in descending
37 * order.
38 */
39#define find_closest_descending(x, a, as) __find_closest(x, a, as, >=)
40
41#endif

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _LINUX_HELPER_MACROS_H_
 3#define _LINUX_HELPER_MACROS_H_
 4
 5#define __find_closest(x, a, as, op)					\
 6({									\
 7	typeof(as) __fc_i, __fc_as = (as) - 1;				\
 8	typeof(x) __fc_x = (x);						\
 9	typeof(*a) const *__fc_a = (a);					\
10	for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) {			\
11		if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] +	\
12						__fc_a[__fc_i + 1], 2))	\
13			break;						\
14	}								\
15	(__fc_i);							\
16})
17
18/**
19 * find_closest - locate the closest element in a sorted array
20 * @x: The reference value.
21 * @a: The array in which to look for the closest element. Must be sorted
22 *  in ascending order.
23 * @as: Size of 'a'.
24 *
25 * Returns the index of the element closest to 'x'.
26 */
27#define find_closest(x, a, as) __find_closest(x, a, as, <=)
28
29/**
30 * find_closest_descending - locate the closest element in a sorted array
31 * @x: The reference value.
32 * @a: The array in which to look for the closest element. Must be sorted
33 *  in descending order.
34 * @as: Size of 'a'.
35 *
36 * Similar to find_closest() but 'a' is expected to be sorted in descending
37 * order.
38 */
39#define find_closest_descending(x, a, as) __find_closest(x, a, as, >=)
40
41#endif