1 #ifndef __LINUX_COMPILER_H
2 #define __LINUX_COMPILER_H
5 # define __user __attribute__((noderef, address_space(1)))
6 # define __kernel /* default address space */
7 # define __safe __attribute__((safe))
18 # include <linux/compiler-gcc+.h> /* catch-all for GCC 4, 5, etc. */
20 # include <linux/compiler-gcc3.h>
22 # include <linux/compiler-gcc2.h>
24 # error Sorry, your compiler is too old/not recognized.
28 /* Intel compiler defines __GNUC__. So we will overwrite implementations
29 * coming from above header files here
31 #ifdef __INTEL_COMPILER
32 # include <linux/compiler-intel.h>
36 * Generic compiler-dependent macros required for kernel
37 * build go below this comment. Actual compiler/compiler version
38 * specific implementations come from the above header files
41 #define likely(x) __builtin_expect(!!(x), 1)
42 #define unlikely(x) __builtin_expect(!!(x), 0)
44 /* Optimization barrier */
46 # define barrier() __memory_barrier()
50 # define RELOC_HIDE(ptr, off) \
51 ({ unsigned long __ptr; \
52 __ptr = (unsigned long) (ptr); \
53 (typeof(ptr)) (__ptr + (off)); })
56 #endif /* __KERNEL__ */
59 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
60 * warning for each use, in hopes of speeding the functions removal.
62 * int __deprecated foo(void)
65 # define __deprecated /* unimplemented */
69 * Allow us to avoid 'defined but not used' warnings on functions and data,
70 * as well as force them to be emitted to the assembly file.
72 * As of gcc 3.3, static functions that are not marked with attribute((used))
73 * may be elided from the assembly file. As of gcc 3.3, static data not so
74 * marked will not be elided, but this may change in a future gcc version.
76 * In prior versions of gcc, such functions and data would be emitted, but
77 * would be warned about except with attribute((unused)).
79 #ifndef __attribute_used__
80 # define __attribute_used__ /* unimplemented */
84 * From the GCC manual:
86 * Many functions have no effects except the return value and their
87 * return value depends only on the parameters and/or global
88 * variables. Such a function can be subject to common subexpression
89 * elimination and loop optimization just as an arithmetic operator
93 #ifndef __attribute_pure__
94 # define __attribute_pure__ /* unimplemented */
98 * From the GCC manual:
100 * Many functions do not examine any values except their arguments,
101 * and have no effects except the return value. Basically this is
102 * just slightly more strict class than the `pure' attribute above,
103 * since function is not allowed to read global memory.
105 * Note that a function that has pointer arguments and examines the
106 * data pointed to must _not_ be declared `const'. Likewise, a
107 * function that calls a non-`const' function usually must not be
108 * `const'. It does not make sense for a `const' function to return
111 #ifndef __attribute_const__
112 # define __attribute_const__ /* unimplemented */
119 #endif /* __LINUX_COMPILER_H */