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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2012-06-13 11:39:43 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2012-06-14 14:20:30 +0200 |
| commit | c34bb0dcfa8ba1294cd5182349e1ddbe34f81bf4 (patch) | |
| tree | 249469ef52fd9829a59ca914322805c351267da1 /cpukit/score/include/rtems/score/timestamp64.h | |
| parent | score: New structure TOD_Control (diff) | |
| download | rtems-c34bb0dcfa8ba1294cd5182349e1ddbe34f81bf4.tar.bz2 | |
score: Fix performance issue for 64-bit timestamps
The 64-bit timestamps were introduced to simplify the timestamp
calculations. This works well since nearly all operations are
additions. The previous _TOD_Tickle_ticks() implementation had a
serious performance regression in case of 64-bit timestamps due to the
usage of two 64-bit divisions which are quite expensive on some
architectures.
A new field seconds_trigger in TOD_Control is introduced to trigger the
_Watchdog_Tickle_seconds() in _TOD_Tickle_ticks(). This avoids the
64-bit divisions completely and only 32-bit additions are used.
Diffstat (limited to 'cpukit/score/include/rtems/score/timestamp64.h')
| -rw-r--r-- | cpukit/score/include/rtems/score/timestamp64.h | 30 |
1 files changed, 0 insertions, 30 deletions
diff --git a/cpukit/score/include/rtems/score/timestamp64.h b/cpukit/score/include/rtems/score/timestamp64.h index 08d3ac7ecd..1c1ea2c90c 100644 --- a/cpukit/score/include/rtems/score/timestamp64.h +++ b/cpukit/score/include/rtems/score/timestamp64.h @@ -209,36 +209,6 @@ static inline void _Timestamp64_implementation_Add_to( #endif /** - * @brief Add to a Timestamp (At Clock Tick) - * - * This routine adds two timestamps. The second argument is added - * to the first. - * - * @node This routine places a special requirement on the addition - * operation. It must return the number of units that the - * seconds field changed as the result of the addition. Since this - * operation is ONLY used as part of processing a clock tick, - * it is generally safe to assume that only one second changed. - * - * @param[in] _time points to the base time to be added to - * @param[in] _add points to the timestamp to add to the first argument - * - * @return This method returns the number of seconds @a time increased by. - */ -static inline uint32_t _Timestamp64_Add_to_at_tick( - Timestamp64_Control *_time, - const Timestamp64_Control *_add -) -{ - Timestamp64_Control _start = *_time / 1000000000L; - *_time += *_add; - if ( ((*_time) / 1000000000L) != _start ) { - return 1; - } - return 0; -} - -/** * @brief Convert Timestamp to Number of Ticks * * This routine convert the @a time timestamp to the corresponding number |