assume.h

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#ifndef RBIMPL_ASSUME_H                              /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ASSUME_H
#include "ruby/internal/config.h"
#include "ruby/internal/cast.h"
#include "ruby/internal/compiler_since.h"
#include "ruby/internal/has/builtin.h"
#include "ruby/internal/warning_push.h"
 
#if defined(HAVE___ASSUME)
# define RBIMPL_HAVE___ASSUME
#endif
#if RBIMPL_HAS_BUILTIN(__builtin_unreachable)
# define RBIMPL_UNREACHABLE_RETURN(_) __builtin_unreachable()
 
#elif defined(RBIMPL_HAVE___ASSUME)
# define RBIMPL_UNREACHABLE_RETURN(_) return (__assume(0), (_))
 
#else
# define RBIMPL_UNREACHABLE_RETURN(_) return (_)
#endif
 
#if RBIMPL_HAS_BUILTIN(__builtin_unreachable)
# define RBIMPL_UNREACHABLE __builtin_unreachable
 
#elif defined(RBIMPL_HAVE___ASSUME)
# define RBIMPL_UNREACHABLE() __assume(0)
#endif
 
#if RBIMPL_COMPILER_SINCE(Intel, 13, 0, 0)
# /* icc warnings are false positives.  Ignore them. */
# /* "warning #2261: __assume expression with side effects discarded" */
# define RBIMPL_ASSUME(expr)     \
    RBIMPL_WARNING_PUSH()        \
    RBIMPL_WARNING_IGNORED(2261) \
    __assume(expr)              \
    RBIMPL_WARNING_POP()
 
#elif defined(RBIMPL_HAVE___ASSUME)
# define RBIMPL_ASSUME __assume
 
#elif RBIMPL_HAS_BUILTIN(__builtin_assume)
# define RBIMPL_ASSUME __builtin_assume
 
#elif ! defined(RBIMPL_UNREACHABLE)
# define RBIMPL_ASSUME(_) RBIMPL_CAST((void)(_))
 
#else
# define RBIMPL_ASSUME(_) \
    (RB_LIKELY(!!(_)) ? RBIMPL_CAST((void)0) : RBIMPL_UNREACHABLE())
#endif
 
#if ! defined(RBIMPL_UNREACHABLE)
# define RBIMPL_UNREACHABLE() RBIMPL_ASSUME(0)
#endif
 
#endif /* RBIMPL_ASSUME_H */