LXR linux-bk/include/linux/compiler.h

   1#ifndef __LINUX_COMPILER_H
   2#define __LINUX_COMPILER_H
   3
   4#ifdef __CHECKER__
   5# define __user         __attribute__((noderef, address_space(1)))
   6# define __kernel       /* default address space */
   7#else
   8# define __user
   9# define __kernel
  10#endif
  11
  12#ifndef __ASSEMBLY__
  13#if __GNUC__ > 3
  14# include <linux/compiler-gcc+.h>       /* catch-all for GCC 4, 5, etc. */
  15#elif __GNUC__ == 3
  16# include <linux/compiler-gcc3.h>
  17#elif __GNUC__ == 2
  18# include <linux/compiler-gcc2.h>
  19#else
  20# error Sorry, your compiler is too old/not recognized.
  21#endif
  22#endif
  23
  24/* Intel compiler defines __GNUC__. So we will overwrite implementations
  25 * coming from above header files here
  26 */
  27#ifdef __INTEL_COMPILER
  28# include <linux/compiler-intel.h>
  29#endif
  30
  31/*
  32 * Generic compiler-dependent macros required for kernel
  33 * build go below this comment. Actual compiler/compiler version
  34 * specific implementations come from the above header files
  35 */
  36
  37#define likely(x)       __builtin_expect(!!(x), 1)
  38#define unlikely(x)     __builtin_expect(!!(x), 0)
  39
  40/*
  41 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
  42 * warning for each use, in hopes of speeding the functions removal.
  43 * Usage is:
  44 *              int __deprecated foo(void)
  45 */
  46#ifndef __deprecated
  47# define __deprecated           /* unimplemented */
  48#endif
  49
  50/*
  51 * Allow us to avoid 'defined but not used' warnings on functions and data,
  52 * as well as force them to be emitted to the assembly file.
  53 *
  54 * As of gcc 3.3, static functions that are not marked with attribute((used))
  55 * may be elided from the assembly file.  As of gcc 3.3, static data not so
  56 * marked will not be elided, but this may change in a future gcc version.
  57 *
  58 * In prior versions of gcc, such functions and data would be emitted, but
  59 * would be warned about except with attribute((unused)).
  60 */
  61#ifndef __attribute_used__
  62# define __attribute_used__     /* unimplemented */
  63#endif
  64
  65/*
  66 * From the GCC manual:
  67 *
  68 * Many functions have no effects except the return value and their
  69 * return value depends only on the parameters and/or global
  70 * variables.  Such a function can be subject to common subexpression
  71 * elimination and loop optimization just as an arithmetic operator
  72 * would be.
  73 * [...]
  74 */
  75#ifndef __attribute_pure__
  76# define __attribute_pure__     /* unimplemented */
  77#endif
  78
  79/* Optimization barrier */
  80#ifndef barrier
  81# define barrier() __memory_barrier()
  82#endif
  83
  84#ifndef RELOC_HIDE
  85# define RELOC_HIDE(ptr, off)                                   \
  86  ({ unsigned long __ptr;                                       \
  87     __ptr = (unsigned long) (ptr);                             \
  88    (typeof(ptr)) (__ptr + (off)); })
  89#endif
  90
  91#endif /* __LINUX_COMPILER_H */
  92