smartdns/include/gcc_builtin.h

#ifndef _TOOLS_LINUX_COMPILER_H_
#define _TOOLS_LINUX_COMPILER_H_

#ifndef __compiletime_error
# define __compiletime_error(message)
#endif

/* Optimization barrier */
/* The "volatile" is due to gcc bugs */
#define barrier() __asm__ __volatile__("": : :"memory")

#ifndef __always_inline
# define __always_inline	inline __attribute__((always_inline))
#endif

#ifndef noinline
#define noinline
#endif

/* Are two types/vars the same type (ignoring qualifiers)? */
#ifndef __same_type
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#endif

#ifdef __ANDROID__
/*
 * FIXME: Big hammer to get rid of tons of:
 *   "warning: always_inline function might not be inlinable"
 *
 * At least on android-ndk-r12/platforms/android-24/arch-arm
 */
#undef __always_inline
#define __always_inline	inline
#endif

#define __user
#define __rcu
#define __read_mostly

#ifndef __attribute_const__
# define __attribute_const__
#endif

#ifndef __maybe_unused
# define __maybe_unused		__attribute__((unused))
#endif

#ifndef __used
# define __used		__attribute__((__unused__))
#endif

#ifndef __packed
# define __packed		__attribute__((__packed__))
#endif

#ifndef __force
# define __force
#endif

#ifndef __weak
# define __weak			__attribute__((weak))
#endif

#ifndef likely
# define likely(x)		__builtin_expect(!!(x), 1)
#endif

#ifndef unlikely
# define unlikely(x)		__builtin_expect(!!(x), 0)
#endif

#ifndef __init
# define __init
#endif

#ifndef noinline
# define noinline
#endif

#define uninitialized_var(x) x = *(&(x))

#ifndef __fallthrough
# define __fallthrough
#endif

#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

#ifndef max
#define max(x, y) ({				\
	typeof(x) _max1 = (x);			\
	typeof(y) _max2 = (y);			\
	(void) (&_max1 == &_max2);		\
	_max1 > _max2 ? _max1 : _max2; })
#endif

#ifndef min
#define min(x, y) ({				\
	typeof(x) _min1 = (x);			\
	typeof(y) _min2 = (y);			\
	(void) (&_min1 == &_min2);		\
	_min1 < _min2 ? _min1 : _min2; })
#endif

#ifndef roundup
#define roundup(x, y) (                                \
{                                                      \
	const typeof(y) __y = y;		       \
	(((x) + (__y - 1)) / __y) * __y;	       \
}                                                      \
)
#endif

#define __round_mask(x, y) ((__typeof__(x))((y)-1))
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))

#endif /* _TOOLS_LINUX_COMPILER_H */