score: Optimize scheduler priority updates

Thread priority changes may append or prepend the thread to its priority
group on the scheduler ready queue.  Previously, a separate priority
value and a prepend-it flag in the scheduler node were used to propagate
a priority change to the scheduler.

Now, use an append-it bit in the priority control and reduce the plain
priority value to 63 bits.

This change leads to a significant code size reduction (about 25%) of
the SMP schedulers.  The negligible increase of the standard priority
scheduler is due to some additional shift operations
(SCHEDULER_PRIORITY_MAP() and SCHEDULER_PRIORITY_UNMAP()).

Before:

   text filename
    136 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleblock.o
    464 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimplechangepriority.o
     24 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimple.o
    108 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleschedule.o
    292 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleunblock.o
    264 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleyield.o

   text filename
    280 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityblock.o
    488 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerprioritychangepriority.o
    200 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriority.o
    164 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityschedule.o
    328 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityunblock.o
    200 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityyield.o

   text filename
  24112 arm-rtems5/c/imx7/cpukit/score/src/libscore_a-scheduleredfsmp.o

   text filename
  37204 sparc-rtems5/c/gr740/cpukit/score/src/libscore_a-scheduleredfsmp.o

   text filename
  42236 powerpc-rtems5/c/qoriq_e6500_32/cpukit/score/src/libscore_a-scheduleredfsmp.o

After:

   text filename
    136 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleblock.o
    272 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimplechangepriority.o
     24 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimple.o
    108 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleschedule.o
    292 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleunblock.o
    264 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleyield.o

   text filename
    280 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityblock.o
    488 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerprioritychangepriority.o
    208 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriority.o
    164 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityschedule.o
    332 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityunblock.o
    200 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityyield.o

   text filename
  18860 arm-rtems5/c/imx7/cpukit/score/src/libscore_a-scheduleredfsmp.o

   text filename
  28520 sparc-rtems5/c/gr740/cpukit/score/src/libscore_a-scheduleredfsmp.o

   text filename
  32664 powerpc-rtems5/c/qoriq_e6500_32/cpukit/score/src/libscore_a-scheduleredfsmp.o

1 files changed, 4 insertions, 18 deletions

diff --git a/cpukit/score/include/rtems/score/scheduleredfimpl.h b/cpukit/score/include/rtems/score/scheduleredfimpl.h
index 94a78fcff5..f6bd7d8384 100644
--- a/cpukit/score/include/rtems/score/scheduleredfimpl.h
+++ b/cpukit/score/include/rtems/score/scheduleredfimpl.h
@@ -79,7 +79,7 @@ RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Less(
   return prio_left < prio_right;
 }
 
-RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Less_or_equal(
+RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Priority_less_equal(
   const void        *left,
   const RBTree_Node *right
 )
@@ -101,28 +101,14 @@ RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Less_or_equal(
 RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Enqueue(
   Scheduler_EDF_Context *context,
   Scheduler_EDF_Node    *node,
-  Priority_Control       priority
+  Priority_Control       insert_priority
 )
 {
   _RBTree_Insert_inline(
     &context->Ready,
     &node->Node,
-    &priority,
-    _Scheduler_EDF_Less
-  );
-}
-
-RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Enqueue_first(
-  Scheduler_EDF_Context *context,
-  Scheduler_EDF_Node    *node,
-  Priority_Control       priority
-)
-{
-  _RBTree_Insert_inline(
-    &context->Ready,
-    &node->Node,
-    &priority,
-    _Scheduler_EDF_Less_or_equal
+    &insert_priority,
+    _Scheduler_EDF_Priority_less_equal
   );
 }