text: #ifndef __LINUX_COMPILER_H
  #define __LINUX_COMPILER_H
  
  #ifndef __ASSEMBLY__
  
  #ifdef __CHECKER__
  # define __user		__attribute__((noderef, address_space(1)))
  # define __kernel	/* default address space */
  # define __safe		__attribute__((safe))
  # define __force	__attribute__((force))
  # define __nocast	__attribute__((nocast))
  # define __iomem	__attribute__((noderef, address_space(2)))
  # define __acquires(x)	__attribute__((context(x,0,1)))
  # define __releases(x)	__attribute__((context(x,1,0)))
  # define __acquire(x)	__context__(x,1)
  # define __release(x)	__context__(x,-1)
  # define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)
  extern void __chk_user_ptr(const volatile void __user *);
  extern void __chk_io_ptr(const volatile void __iomem *);
  #else
  # define __user
  # define __kernel
  # define __safe
  # define __force
  # define __nocast
  # define __iomem
  # define __chk_user_ptr(x) (void)0
  # define __chk_io_ptr(x) (void)0
  # define __builtin_warning(x, y...) (1)
  # define __acquires(x)
  # define __releases(x)
  # define __acquire(x) (void)0
  # define __release(x) (void)0
  # define __cond_lock(x,c) (c)
  #endif
  
  #ifdef __KERNEL__
  
  #if __GNUC__ >= 4
  # include <linux/compiler-gcc4.h>
  #elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2
  # include <linux/compiler-gcc3.h>
  #else
  # error Sorry, your compiler is too old/not recognized.
  #endif
  
  /* Intel compiler defines __GNUC__. So we will overwrite implementations
   * coming from above header files here
   */
  #ifdef __INTEL_COMPILER
  # include <linux/compiler-intel.h>
  #endif
  
  /*
   * Generic compiler-dependent macros required for kernel
   * build go below this comment. Actual compiler/compiler version
   * specific implementations come from the above header files
   */
  
  #define likely(x)	__builtin_expect(!!(x), 1)
  #define unlikely(x)	__builtin_expect(!!(x), 0)
  
  /* Optimization barrier */
  #ifndef barrier
  # define barrier() __memory_barrier()
  #endif
  
  #ifndef RELOC_HIDE
  # define RELOC_HIDE(ptr, off)					\
    ({ unsigned long __ptr;					\
       __ptr = (unsigned long) (ptr);				\
      (typeof(ptr)) (__ptr + (off)); })
  #endif
  
  #endif /* __KERNEL__ */
  
  #endif /* __ASSEMBLY__ */
  
  #ifdef __KERNEL__
  /*
   * Allow us to mark functions as 'deprecated' and have gcc emit a nice
   * warning for each use, in hopes of speeding the functions removal.
   * Usage is:
   * 		int __deprecated foo(void)
   */
  #ifndef __deprecated
  # define __deprecated		/* unimplemented */
  #endif
  
  #ifdef MODULE
  #define __deprecated_for_modules __deprecated
  #else
  #define __deprecated_for_modules
  #endif
  
  #ifndef __must_check
  #define __must_check
  #endif
  
  #ifndef CONFIG_ENABLE_MUST_CHECK
  #undef __must_check
  #define __must_check
  #endif
  
  /*
   * Allow us to avoid 'defined but not used' warnings on functions and data,
   * as well as force them to be emitted to the assembly file.
   *
   * As of gcc 3.4, static functions that are not marked with attribute((used))
   * may be elided from the assembly file.  As of gcc 3.4, static data not so
   * marked will not be elided, but this may change in a future gcc version.
   *
   * NOTE: Because distributions shipped with a backported unit-at-a-time
   * compiler in gcc 3.3, we must define __used to be __attribute__((used))
   * for gcc >=3.3 instead of 3.4.
   *
   * In prior versions of gcc, such functions and data would be emitted, but
   * would be warned about except with attribute((unused)).
   *
   * Mark functions that are referenced only in inline assembly as __used so
   * the code is emitted even though it appears to be unreferenced.
   */
  #ifndef __attribute_used__
  # define __attribute_used__	/* deprecated */
  #endif
  
  #ifndef __used
  # define __used			/* unimplemented */
  #endif
  
  #ifndef __maybe_unused
  # define __maybe_unused		/* unimplemented */
  #endif
  
  /*
   * 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.
   * [...]
   */
  #ifndef __attribute_pure__
  # define __attribute_pure__	/* unimplemented */
  #endif
  
  #ifndef noinline
  #define noinline
  #endif
  
  #ifndef __always_inline
  #define __always_inline inline
  #endif
  
  #endif /* __KERNEL__ */
  
  /*
   * From the GCC manual:
   *
   * Many functions do not examine any values except their arguments,
   * and have no effects except the return value.  Basically this is
   * just slightly more strict class than the `pure' attribute above,
   * since function is not allowed to read global memory.
   *
   * Note that a function that has pointer arguments and examines the
   * data pointed to must _not_ be declared `const'.  Likewise, a
   * function that calls a non-`const' function usually must not be
   * `const'.  It does not make sense for a `const' function to return
   * `void'.
   */
  #ifndef __attribute_const__
  # define __attribute_const__	/* unimplemented */
  #endif
  
  /*
   * Tell gcc if a function is cold. The compiler will assume any path
   * directly leading to the call is unlikely.
   */
  
  #ifndef __cold
  #define __cold
  #endif
  
  /* Simple shorthand for a section definition */
  #ifndef __section
  # define __section(S) __attribute__ ((__section__(#S)))
  #endif
  
  /* Are two types/vars the same type (ignoring qualifiers)? */
  #ifndef __same_type
  # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
  #endif
  
  /*
   * Prevent the compiler from merging or refetching accesses.  The compiler
   * is also forbidden from reordering successive instances of ACCESS_ONCE(),
   * but only when the compiler is aware of some particular ordering.  One way
   * to make the compiler aware of ordering is to put the two invocations of
   * ACCESS_ONCE() in different C statements.
   *
   * This macro does absolutely -nothing- to prevent the CPU from reordering,
   * merging, or refetching absolutely anything at any time.  Its main intended
   * use is to mediate communication between process-level code and irq/NMI
   * handlers, all running on the same CPU.
   */
  #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
  
  #endif /* __LINUX_COMPILER_H */
  