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/* Optimization barrier */

#define barrier() __asm__ __volatile__("": : :"memory")

/*

 * This version is i.e. to prevent dead stores elimination on @ptr

 * where gcc and llvm may behave differently when otherwise using

 * normal barrier(): while gcc behavior gets along with a normal

 * barrier(), llvm needs an explicit input variable to be assumed

 * clobbered. The issue is as follows: while the inline asm might

 * access any memory it wants, the compiler could have fit all of

 * @ptr into memory registers instead, and since @ptr never escaped

 * from that, it proofed that the inline asm wasn't touching any of

 * it. This version works well with both compilers, i.e. we're telling

 * the compiler that the inline asm absolutely may see the contents

 * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495

 */

({									\

})

/* Make the optimizer believe the variable can be manipulated arbitrarily. */

#define __always_inline	inline __attribute__((always_inline))

#define  noinline	__attribute__((noinline))

#define __weak		__attribute__((weak))

 * The asm() bodies of naked functions often depend on standard calling

 *

/* gcc version specific checks */

#if GCC_VERSION < 30200

# error Sorry, your compiler is too old - please upgrade it.

#endif

#if GCC_VERSION < 30300

# define __used			__attribute__((__unused__))

#else

# define __used			__attribute__((__used__))

#endif

#ifdef CONFIG_GCOV_KERNEL

# if GCC_VERSION < 30400

#   error "GCOV profiling support for gcc versions below 3.4 not included"

# endif /* __GNUC_MINOR__ */

#endif /* CONFIG_GCOV_KERNEL */

#if GCC_VERSION >= 30400

#define __must_check		__attribute__((warn_unused_result))

#endif

#if GCC_VERSION >= 40000

/* GCC 4.1.[01] miscompiles __weak */

#ifdef __KERNEL__

# if GCC_VERSION >= 40100 &&  GCC_VERSION <= 40101

#  error Your version of gcc miscompiles the __weak directive

# endif

#endif

#define __compiler_offsetof(a, b)					\

	__builtin_offsetof(a, b)

#if GCC_VERSION >= 40100 && GCC_VERSION < 40600

# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)

#endif

#if GCC_VERSION >= 40300

/* Mark functions as cold. gcc will assume any path leading to a call

 * to them will be unlikely.  This means a lot of manual unlikely()s

 * are unnecessary now for any paths leading to the usual suspects

 * like BUG(), printk(), panic() etc. [but let's keep them for now for

 * older compilers]

 *

 * Early snapshots of gcc 4.3 don't support this and we can't detect this

 * in the preprocessor, but we can live with this because they're unreleased.

 * Maketime probing would be overkill here.

 *

 * gcc also has a __attribute__((__hot__)) to move hot functions into

 * a special section, but I don't see any sense in this right now in

 * the kernel context

 */

#define __cold			__attribute__((__cold__))

#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)

#ifndef __CHECKER__

# define __compiletime_error(message) __attribute__((error(message)))

#endif /* __CHECKER__ */

#endif /* GCC_VERSION >= 40300 */

#if GCC_VERSION >= 40500

/*

 * Mark a position in code as unreachable.  This can be used to

 * suppress control flow warnings after asm blocks that transfer

 * control elsewhere.

 *

 * Early snapshots of gcc 4.5 don't support this and we can't detect

 * this in the preprocessor, but we can live with this because they're

 * unreleased.  Really, we need to have autoconf for the kernel.

#define unreachable() __builtin_unreachable()

/* Mark a function definition as prohibited from being cloned. */

#define __noclone	__attribute__((__noclone__))

#endif /* GCC_VERSION >= 40500 */

#if GCC_VERSION >= 40600

/*

 * When used with Link Time Optimization, gcc can optimize away C functions or

 * variables which are referenced only from assembly code.  __visible tells the

 * optimizer that something else uses this function or variable, thus preventing

 * this.

 */

#define __visible	__attribute__((externally_visible))

#endif

#if GCC_VERSION >= 40900 && !defined(__CHECKER__)

/*

 * __assume_aligned(n, k): Tell the optimizer that the returned

 * pointer can be assumed to be k modulo n. The second argument is

 * optional (default 0), so we use a variadic macro to make the

 * shorthand.

 *

 * Beware: Do not apply this to functions which may return

 * ERR_PTRs. Also, it is probably unwise to apply it to functions

 * returning extra information in the low bits (but in that case the

 * compiler should see some alignment anyway, when the return value is

 * massaged by 'flags = ptr & 3; ptr &= ~3;').

 */

#define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))

#endif

/*

 * GCC 'asm goto' miscompiles certain code sequences:

 *

 *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

 *

 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.

 *

 * (asm goto is automatically volatile - the naming reflects this.)

 */

#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)

#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP

#if GCC_VERSION >= 40400

#define __HAVE_BUILTIN_BSWAP32__

#define __HAVE_BUILTIN_BSWAP64__

#endif

#define __HAVE_BUILTIN_BSWAP16__

#endif

#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */

#if GCC_VERSION >= 50000

#define KASAN_ABI_VERSION 4

#elif GCC_VERSION >= 40902

#define KASAN_ABI_VERSION 3

#endif

#if GCC_VERSION >= 40902

/*

 * Tell the compiler that address safety instrumentation (KASAN)

 * should not be applied to that function.

 * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368

 */

#define __no_sanitize_address __attribute__((no_sanitize_address))

#endif

#define __noclone	/* not needed */

#endif

#if !defined(__no_sanitize_address)