utils.h

#ifndef __LIBDRAGON_UTILS_H
#define __LIBDRAGON_UTILS_H
 
#include <string.h>  // memcpy
 
#define SWAP(a, b) ({ typeof(a) t = a; a = b; b = t; })
 
#define MAX(a,b)  ({ typeof(a) _a = a; typeof(b) _b = b; _a > _b ? _a : _b; })
#define MIN(a,b)  ({ typeof(a) _a = a; typeof(b) _b = b; _a < _b ? _a : _b; })
#define CLAMP(x, min, max) (MIN(MAX((x), (min)), (max)))
 
#define ROUND_UP(n, d) ({ \
    typeof(n) _n = n; typeof(d) _d = d; \
    (((_n) + (_d) - 1) / (_d) * (_d)); \
})
 
#define ROUND_DOWN(n, d) ({ \
    typeof(n) _n = n; typeof(d) _d = d; \
    ((_n >= 0) ? ((_n) / (_d) * (_d)) : -(((-_n + (_d) - 1) / (_d)) * (_d))); \
})
 
#define DIVIDE_CEIL(n, d) ({ \
    typeof(n) _n = n; typeof(d) _d = d; \
    ((_n) + (_d) - 1) / (_d); \
})
 
#define ABS(x) ({ \
    typeof(x) _x = x; \
    (_x < 0 ? -_x : _x); \
})
 
#define F2I(f)   ({ uint32_t __i; memcpy(&__i, &(f), 4); __i; })
 
#define I2F(i)   ({ float __f; memcpy(&__f, &(i), 4); __f; })
 
#define LIKELY(cond)    __builtin_expect(!!(cond), 1)
#define UNLIKELY(cond)  __builtin_expect(!!(cond), 0)
 
#endif