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