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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-07-24 09:00:18 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-07-25 10:07:42 +0200 |
| commit | a1f7d7d430466fe66ead3155a9015ddde237fd44 (patch) | |
| tree | 345c928410b1a7216b48473f4792742389b540e1 /cpukit/include/rtems/score/basedefs.h | |
| parent | _SMP_Start_multitasking_on_secondary_processor() (diff) | |
| download | rtems-a1f7d7d430466fe66ead3155a9015ddde237fd44.tar.bz2 | |
score: RTEMS_PREDICT_TRUE(), RTEMS_PREDICT_FALSE()
Add RTEMS_PREDICT_TRUE() and RTEMS_PREDICT_FALSE() for static branch
prediction hints.
Close #3475.
Diffstat (limited to 'cpukit/include/rtems/score/basedefs.h')
| -rw-r--r-- | cpukit/include/rtems/score/basedefs.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/cpukit/include/rtems/score/basedefs.h b/cpukit/include/rtems/score/basedefs.h index 8169f6db8c..679f4bd1b4 100644 --- a/cpukit/include/rtems/score/basedefs.h +++ b/cpukit/include/rtems/score/basedefs.h @@ -281,6 +281,34 @@ #define RTEMS_DEFINE_GLOBAL_SYMBOL( _name, _value ) #endif +/** + * @brief Returns the value of the specified integral expression and tells the + * compiler that the predicted value is true (1). + * + * @param[in] _exp The expression. + * + * @return The value of the expression. + */ +#if defined(__GNUC__) + #define RTEMS_PREDICT_TRUE( _exp ) __builtin_expect( ( _exp ), 1 ) +#else + #define RTEMS_PREDICT_TRUE( _exp ) ( _exp ) +#endif + +/** + * @brief Returns the value of the specified integral expression and tells the + * compiler that the predicted value is false (0). + * + * @param[in] _exp The expression. + * + * @return The value of the expression. + */ +#if defined(__GNUC__) + #define RTEMS_PREDICT_FALSE( _exp ) __builtin_expect( ( _exp ), 0 ) +#else + #define RTEMS_PREDICT_FALSE( _exp ) ( _exp ) +#endif + #if __cplusplus >= 201103L #define RTEMS_STATIC_ASSERT(cond, msg) \ static_assert(cond, # msg) |