1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _LINUX_HELPER_MACROS_H_ 3*4882a593Smuzhiyun #define _LINUX_HELPER_MACROS_H_ 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #define __find_closest(x, a, as, op) \ 6*4882a593Smuzhiyun ({ \ 7*4882a593Smuzhiyun typeof(as) __fc_i, __fc_as = (as) - 1; \ 8*4882a593Smuzhiyun typeof(x) __fc_x = (x); \ 9*4882a593Smuzhiyun typeof(*a) const *__fc_a = (a); \ 10*4882a593Smuzhiyun for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) { \ 11*4882a593Smuzhiyun if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] + \ 12*4882a593Smuzhiyun __fc_a[__fc_i + 1], 2)) \ 13*4882a593Smuzhiyun break; \ 14*4882a593Smuzhiyun } \ 15*4882a593Smuzhiyun (__fc_i); \ 16*4882a593Smuzhiyun }) 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun /** 19*4882a593Smuzhiyun * find_closest - locate the closest element in a sorted array 20*4882a593Smuzhiyun * @x: The reference value. 21*4882a593Smuzhiyun * @a: The array in which to look for the closest element. Must be sorted 22*4882a593Smuzhiyun * in ascending order. 23*4882a593Smuzhiyun * @as: Size of 'a'. 24*4882a593Smuzhiyun * 25*4882a593Smuzhiyun * Returns the index of the element closest to 'x'. 26*4882a593Smuzhiyun */ 27*4882a593Smuzhiyun #define find_closest(x, a, as) __find_closest(x, a, as, <=) 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun /** 30*4882a593Smuzhiyun * find_closest_descending - locate the closest element in a sorted array 31*4882a593Smuzhiyun * @x: The reference value. 32*4882a593Smuzhiyun * @a: The array in which to look for the closest element. Must be sorted 33*4882a593Smuzhiyun * in descending order. 34*4882a593Smuzhiyun * @as: Size of 'a'. 35*4882a593Smuzhiyun * 36*4882a593Smuzhiyun * Similar to find_closest() but 'a' is expected to be sorted in descending 37*4882a593Smuzhiyun * order. 38*4882a593Smuzhiyun */ 39*4882a593Smuzhiyun #define find_closest_descending(x, a, as) __find_closest(x, a, as, >=) 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun #endif 42