/*

 * Copyright 2008-2011 Various Authors

 * Copyright 2005 Timo Hirvonen

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 of the

 * License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#ifndef COMPILER_H

#define COMPILER_H

#include <stddef.h>

/*

 * GCC 2.96 or compatible required

 */

#if defined(__GNUC__)

#if __GNUC__ > 3

#undef offsetof

#define offsetof(type, member) __builtin_offsetof(type, member)

#endif

/* Optimization: Condition @x is likely */

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

/* Optimization: Condition @x is unlikely */

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

#else

#define likely(x)	(x)

#define unlikely(x)	(x)

#endif

/* Optimization: Function never returns */

#define __NORETURN	__attribute__((__noreturn__))

/* Argument at index @fmt_idx is printf compatible format string and

 * argument at index @first_idx is the first format argument */

#define __FORMAT(fmt_idx, first_idx) __attribute__((format(printf, (fmt_idx), (first_idx))))

#if defined(__GNUC__) && (__GNUC__ >= 3)

/* Optimization: Pointer returned can't alias other pointers */

#define __MALLOC	__attribute__((__malloc__))

#else

#define __MALLOC

#endif

/**

 * container_of - cast a member of a structure out to the containing structure

 *

 * @ptr:	the pointer to the member.

 * @type:	the type of the container struct this is embedded in.

 * @member:	the name of the member within the struct.

 *

 */

#define container_of_portable(ptr, type, member) \

	((type *)(void *)( (char *)(ptr) - offsetof(type,member) ))

#undef container_of

#if defined(__GNUC__)

#define container_of(ptr, type, member) __extension__ ({		\

	const __typeof__( ((type *)0)->member ) *__mptr = (ptr);	\

	container_of_portable(__mptr, type, member);})

#else

#define container_of(ptr, type, member) container_of_portable(ptr, type, member)

#endif

#endif