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

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

/*
 * Common definitions for all gcc versions go here.
 */


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

/* This macro obfuscates arithmetic on a variable address so that gcc
   shouldn't recognize the original var, and make assumptions about it */
/*
 * Versions of the ppc64 compiler before 4.1 had a bug where use of
 * RELOC_HIDE could trash r30. The bug can be worked around by changing
 * the inline assembly constraint from =g to =r, in this particular
 * case either is valid.
 */
#define RELOC_HIDE(ptr, off)					\
  ({ unsigned long __ptr;					\
    __asm__ ("" : "=r"(__ptr) : "0"(ptr));		\
    (typeof(ptr)) (__ptr + (off)); })

/* &a[0] degrades to a pointer: a different type from an array */
#define __must_be_array(a) \
  BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))

/*
 * Force always-inline if the user requests it so via the .config,
 * or if gcc is too old:
 */
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
    !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
# define inline		inline		__attribute__((always_inline))
# define __inline__	__inline__	__attribute__((always_inline))
# define __inline	__inline	__attribute__((always_inline))
#endif

#define __deprecated			__attribute__((deprecated))
#define __packed			__attribute__((packed))
#define __weak				__attribute__((weak))
#define __naked				__attribute__((naked))
#define __noreturn			__attribute__((noreturn))

/*
 * From the GCC manual:
 *
 * Many functions have no effects except the return value and their
 * return value depends only on the parameters and/or global
 * variables.  Such a function can be subject to common subexpression
 * elimination and loop optimization just as an arithmetic operator
 * would be.
 * [...]
 */
#define __pure				__attribute__((pure))
#define __aligned(x)			__attribute__((aligned(x)))
#define __printf(a,b)			__attribute__((format(printf,a,b)))
#define  noinline			__attribute__((noinline))
#define __attribute_const__		__attribute__((__const__))
#define __maybe_unused			__attribute__((unused))

#define __gcc_header(x) #x
#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
#define gcc_header(x) _gcc_header(x)
#include gcc_header(__GNUC__)
Commit	Line	Data
94f582f8 RD	1	#ifndef __LINUX_COMPILER_H
	2	#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
	3	#endif
1da177e4 LT	4
	5	/*
	6	* Common definitions for all gcc versions go here.
	7	*/
	8
	9
	10	/* Optimization barrier */
	11	/* The "volatile" is due to gcc bugs */
	12	#define barrier() __asm__ __volatile__("": : :"memory")
	13
	14	/* This macro obfuscates arithmetic on a variable address so that gcc
	15	shouldn't recognize the original var, and make assumptions about it */
c8d52465 AB	16	/*
	17	* Versions of the ppc64 compiler before 4.1 had a bug where use of
	18	* RELOC_HIDE could trash r30. The bug can be worked around by changing
	19	* the inline assembly constraint from =g to =r, in this particular
	20	* case either is valid.
	21	*/
1da177e4 LT	22	#define RELOC_HIDE(ptr, off) \
1da177e4 LT	23	({ unsigned long __ptr; \
c8d52465	24	__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
1da177e4	25	(typeof(ptr)) (__ptr + (off)); })
a1365647	26
c5e631cf RR	27	/* &a[0] degrades to a pointer: a different type from an array */
	28	#define __must_be_array(a) \
	29	BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
a1365647	30
60a3cdd0	31	/*
ae3a0064 IM	32	* Force always-inline if the user requests it so via the .config,
ae3a0064 IM	33	* or if gcc is too old:
60a3cdd0	34	*/
765c68bd	35	#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) \|\| \
ae3a0064	36	!defined(CONFIG_OPTIMIZE_INLINING) \|\| (__GNUC__ < 4)
60a3cdd0 IM	37	# define inline inline __attribute__((always_inline))
	38	# define __inline__ __inline__ __attribute__((always_inline))
	39	# define __inline __inline __attribute__((always_inline))
	40	#endif
	41
a1365647	42	#define __deprecated __attribute__((deprecated))
82ddcb04 RD	43	#define __packed __attribute__((packed))
	44	#define __weak __attribute__((weak))
	45	#define __naked __attribute__((naked))
	46	#define __noreturn __attribute__((noreturn))
e8c44319 RB	47
	48	/*
	49	* From the GCC manual:
	50	*
	51	* Many functions have no effects except the return value and their
	52	* return value depends only on the parameters and/or global
	53	* variables. Such a function can be subject to common subexpression
	54	* elimination and loop optimization just as an arithmetic operator
	55	* would be.
	56	* [...]
	57	*/
82ddcb04 RD	58	#define __pure __attribute__((pure))
	59	#define __aligned(x) __attribute__((aligned(x)))
	60	#define __printf(a,b) __attribute__((format(printf,a,b)))
a1365647	61	#define noinline __attribute__((noinline))
a1365647	62	#define __attribute_const__ __attribute__((__const__))
0d7ebbbc	63	#define __maybe_unused __attribute__((unused))
f153b821 LT	64
	65	#define __gcc_header(x) #x
	66	#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
	67	#define gcc_header(x) _gcc_header(x)
	68	#include gcc_header(__GNUC__)