score: Optimize object lookup

Use the maximum ID for the ID to object translation.  Using the maximum
ID gets rid of an additional load from the object information in
_Objects_Get().  In addition, object lookups fail for every ID in case
the object information is cleared to zero.  This makes it a bit more
robust during system startup (see new tests in spconfig02).

The local table no longer needs a NULL pointer entry at array index
zero.  Adjust all the object iteration loops accordingly.

Remove Objects_Information::minimum_id since it contains only redundant
information.  Add _Objects_Get_minimum_id() to get the minimum ID.

Update #3621.

1 files changed, 8 insertions, 11 deletions

diff --git a/cpukit/score/src/objectgetnoprotection.c b/cpukit/score/src/objectgetnoprotection.c
index 85692234fa..e5045b26de 100644
--- a/cpukit/score/src/objectgetnoprotection.c
+++ b/cpukit/score/src/objectgetnoprotection.c
@@ -25,19 +25,16 @@ Objects_Control *_Objects_Get_no_protection(
   const Objects_Information *information
 )
 {
-  Objects_Control *the_object;
-  uint32_t         index;
+  Objects_Id delta;
+  Objects_Id maximum_id;
+  Objects_Id end;
 
-  /*
-   * You can't just extract the index portion or you can get tricked
-   * by a value between 1 and maximum.
-   */
-  index = id - information->minimum_id + 1;
+  maximum_id = information->maximum_id;
+  delta = maximum_id - id;
+  end = _Objects_Get_index( maximum_id );
 
-  if ( information->maximum >= index ) {
-    if ( (the_object = information->local_table[ index ]) != NULL ) {
-      return the_object;
-    }
+  if ( RTEMS_PREDICT_TRUE( delta < end ) ) {
+    return information->local_table[ end - OBJECTS_INDEX_MINIMUM - delta ];
   }
 
   /*