Searching for the member of an array closest to 'x' is duplicated in several places.
Add two macros that implement this algorithm for arrays sorted both in ascending and descending order. Signed-off-by: Bartosz Golaszewski <[email protected]> --- include/linux/kernel.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d6d630d..f4294da 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -116,6 +116,29 @@ } \ ) +#define __find_closest(x, a, as, op)( \ +{ \ + typeof(as) _i, _as = (as) - 1; \ + typeof(x) _x = (x); \ + typeof(*a) *_a = (a); \ + for (_i = 0; _i < _as; _i++) { \ + if (_x op DIV_ROUND_CLOSEST(_a[_i] + _a[_i + 1], 2)) \ + break; \ + } \ + (_i); \ +} \ +) + +/* + * Given an array 'a' (sorted in ascending order) of size 'as' return + * the index of the element in that array closest to 'x'. + */ +#define find_closest(x, a, as) __find_closest(x, a, as, <=) +/* + * Similar to find_closest(), but 'a' is expected to be sorted + * in descending order. + */ +#define find_closest_desc(x, a, as) __find_closest(x, a, as, >) #define _RET_IP_ (unsigned long)__builtin_return_address(0) #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
