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/*
* klibc/compiler.h
*
* Various compiler features
*/
#ifndef _KLIBC_COMPILER_H
#define _KLIBC_COMPILER_H
/* Specific calling conventions */
#ifdef __i386__
# ifdef __GNUC__
# define __cdecl __attribute__((cdecl,regparm(0)))
# else
/* Most other C compilers have __cdecl as a keyword */
# endif
#endif
/* How to declare a function that *must* be inlined */
#ifdef __GNUC__
# if __GNUC_MAJOR__ >= 3
# define __must_inline static __inline__ __attribute__((always_inline))
# else
# define __must_inline extern __inline__
# endif
#else
# define __must_inline inline /* Just hope this works... */
#endif
/* How to declare a function that does not return */
#ifdef __GNUC__
# define __noreturn void __attribute__((noreturn))
#else
# define __noreturn void
#endif
/* How to declare a "constant" function (a function in the
mathematical sense) */
#ifdef __GNUC__
# define __constfunc __attribute__((const))
#else
# define __constfunc
#endif
/* Format attribute */
#ifdef __GNUC__
# define __formatfunc(t,f,a) __attribute__((format(t,f,a)))
#else
# define __formatfunc(t,f,a)
#endif
/* likely/unlikely */
#if defined(__GNUC__) && (__GNUC_MAJOR__ > 2 || (__GNUC_MAJOR__ == 2 && __GNUC_MINOR__ >= 95))
# define __likely(x) __builtin_expect((x), 1)
# define __unlikely(x) __builtin_expect((x), 0)
#else
# define __likely(x) (x)
# define __unlikely(x) (x)
#endif
/* Possibly unused function */
#ifdef __GNUC__
# define __unusedfunc __attribute__((unused))
#else
# define __unusedfunc
#endif
/* "pure" function:
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. These functions should be declared with the attribute
`pure'.
*/
#ifdef __GNUC__
# define __attribute_pure__ __attribute__((pure))
#else
# define __attribute_pure__
#endif
/* "const" function:
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'.
*/
#ifdef __GNUC__
# define __attribute_const__ __attribute__((const))
#else
# define __attribute_const__
#endif
#endif
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