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