26 lines · c
1#ifndef _TOOLS_MATH_H2#define _TOOLS_MATH_H3 4/*5 * This looks more complex than it should be. But we need to6 * get the type for the ~ right in round_down (it needs to be7 * as wide as the result!), and we want to evaluate the macro8 * arguments just once each.9 */10#define __round_mask(x, y) ((__typeof__(x))((y)-1))11#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)12#define round_down(x, y) ((x) & ~__round_mask(x, y))13 14#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))15 16#ifndef roundup17#define roundup(x, y) ( \18{ \19 const typeof(y) __y = y; \20 (((x) + (__y - 1)) / __y) * __y; \21} \22)23#endif24 25#endif26