[deliverable/linux.git] / include / linux / compiler-gcc4.h

#ifndef __LINUX_COMPILER_H
#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
#endif

/* GCC 4.1.[01] miscompiles __weak */
#ifdef __KERNEL__
# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
#  error Your version of gcc miscompiles the __weak directive
# endif
#endif

#define __used			__attribute__((__used__))
#define __must_check 		__attribute__((warn_unused_result))
#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
#define __always_inline		inline __attribute__((always_inline))

/*
 * A trick to suppress uninitialized variable warning without generating any
 * code
 */
#define uninitialized_var(x) x = x

#if __GNUC_MINOR__ >= 3
/* Mark functions as cold. gcc will assume any path leading to a call
   to them will be unlikely.  This means a lot of manual unlikely()s
   are unnecessary now for any paths leading to the usual suspects
   like BUG(), printk(), panic() etc. [but let's keep them for now for
   older compilers]

   Early snapshots of gcc 4.3 don't support this and we can't detect this
   in the preprocessor, but we can live with this because they're unreleased.
   Maketime probing would be overkill here.

   gcc also has a __attribute__((__hot__)) to move hot functions into
   a special section, but I don't see any sense in this right now in
   the kernel context */
#define __cold			__attribute__((__cold__))

#endif
Commit	Line	Data
94f582f8 RD	1	#ifndef __LINUX_COMPILER_H
	2	#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
	3	#endif
1da177e4	4
f9d14250	5	/* GCC 4.1.[01] miscompiles __weak */
8cd2c29d PA	6	#ifdef __KERNEL__
	7	# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
	8	# error Your version of gcc miscompiles the __weak directive
	9	# endif
f9d14250 LT	10	#endif
f9d14250 LT	11
0d7ebbbc	12	#define __used __attribute__((__used__))
1da177e4 LT	13	#define __must_check __attribute__((warn_unused_result))
1da177e4 LT	14	#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
40fc55cb	15	#define __always_inline inline __attribute__((always_inline))
94909914 BP	16
	17	/*
	18	* A trick to suppress uninitialized variable warning without generating any
	19	* code
	20	*/
	21	#define uninitialized_var(x) x = x
a586df06	22
f153b821	23	#if __GNUC_MINOR__ >= 3
a586df06 AK	24	/* Mark functions as cold. gcc will assume any path leading to a call
	25	to them will be unlikely. This means a lot of manual unlikely()s
	26	are unnecessary now for any paths leading to the usual suspects
	27	like BUG(), printk(), panic() etc. [but let's keep them for now for
	28	older compilers]
	29
	30	Early snapshots of gcc 4.3 don't support this and we can't detect this
	31	in the preprocessor, but we can live with this because they're unreleased.
	32	Maketime probing would be overkill here.
	33
	34	gcc also has a __attribute__((__hot__)) to move hot functions into
	35	a special section, but I don't see any sense in this right now in
	36	the kernel context */
	37	#define __cold __attribute__((__cold__))
	38
	39	#endif