/* SPDX-License-Identifier: GPL-2.0 */
  #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