mirror of
https://github.com/love2d/megasource.git
synced 2026-08-17 19:24:09 +02:00
Miku AuahDark
46 lines
1.3 KiB
C++
46 lines
1.3 KiB
C++
#ifndef OPTHELPERS_H
|
|
#define OPTHELPERS_H
|
|
|
|
#ifdef __has_builtin
|
|
#define HAS_BUILTIN __has_builtin
|
|
#else
|
|
#define HAS_BUILTIN(x) (0)
|
|
#endif
|
|
|
|
#if defined(__GNUC__) || HAS_BUILTIN(__builtin_expect)
|
|
/* LIKELY optimizes the case where the condition is true. The condition is not
|
|
* required to be true, but it can result in more optimal code for the true
|
|
* path at the expense of a less optimal false path.
|
|
*/
|
|
#define LIKELY(x) (__builtin_expect(!!(x), !false))
|
|
/* The opposite of LIKELY, optimizing the case where the condition is false. */
|
|
#define UNLIKELY(x) (__builtin_expect(!!(x), false))
|
|
|
|
#else
|
|
|
|
#define LIKELY(x) (!!(x))
|
|
#define UNLIKELY(x) (!!(x))
|
|
#endif
|
|
|
|
#if HAS_BUILTIN(__builtin_assume)
|
|
/* Unlike LIKELY, ASSUME requires the condition to be true or else it invokes
|
|
* undefined behavior. It's essentially an assert without actually checking the
|
|
* condition at run-time, allowing for stronger optimizations than LIKELY.
|
|
*/
|
|
#define ASSUME __builtin_assume
|
|
#elif defined(_MSC_VER)
|
|
#define ASSUME __assume
|
|
#elif defined(__GNUC__)
|
|
#define ASSUME(x) do { if(!(x)) __builtin_unreachable(); } while(0)
|
|
#else
|
|
#define ASSUME(x) ((void)0)
|
|
#endif
|
|
|
|
#if __cplusplus >= 201703L || defined(__cpp_if_constexpr)
|
|
#define if_constexpr if constexpr
|
|
#else
|
|
#define if_constexpr if
|
|
#endif
|
|
|
|
#endif /* OPTHELPERS_H */
|