[OpenMP][FIX] Do check the level before return team size

[jdoerfert]

Summary

The team size could/should be an ICV but since we know it is either 1 or
a value we can leave it in the team state for now. However, we still
need to determine if the current level is nested before we use it.

[jhuber6]

LG

[protze.joachim]

openmp/libomptarget/DeviceRTL/src/State.cpp

448–451

is state::ParallelTeamSize = 1 for level=0? Probably change to checking for ActiveLevel?

[jdoerfert]

openmp/libomptarget/DeviceRTL/src/State.cpp

448–451

Yes, level == 0 ==> ParallelTeamSize = 1. Why active level? We sequentialize any nested region, regardless if it is active or not. So only for level == 1 there is a reason to for ParallelTeamSize to be effectively not 1. That said, we do not actually modify ParallelTeamSize as it is not an ICV right now. So when we are nested the value stays as it was before, which is why we need this check. If we make it an ICV we could avoid it.

openmp/libomptarget/DeviceRTL/src/State.cpp

 int omp_get_thread_num(void) {
   return omp_get_ancestor_thread_num(omp_get_level());
 }
 
 int omp_get_team_size(int Level) {
   return returnValIfLevelIsActive(Level, state::ParallelTeamSize, 1);
 }
 
-int omp_get_num_threads(void) { return state::ParallelTeamSize; }
+int omp_get_num_threads(void) {
+  return omp_get_level() > 1 ? 1 : state::ParallelTeamSize;
+}
 
 int omp_get_thread_limit(void) { return mapping::getKernelSize(); }
 
 int omp_get_num_procs(void) { return mapping::getNumberOfProcessorElements(); }
 
 void omp_set_nested(int) {}
 
 int omp_get_nested(void) { return false; }