Expanded test with more checking. Still not working due to compiler limitation.

Cases/Composite/OpenMP_Metadirective/OpenMP_metadirective_user_condition_target.f90

-program OpenMP_metadirective_target_test
+program OpenMP_metadirective_user_condition_target_test
 
   use omp_lib
   use iso_fortran_env
   
-  integer :: &
-    iV, &
+  implicit none
+  
+  logical :: &
     UseDevice
+  real ( real64 ) :: &
+    Timing
   real ( real64 ), dimension ( : ), allocatable :: &
-    A, B, C
+    A, B, C, &
+    C_Ref
     
-  UseDevice = 1
+  print*, 'OnDevice ( )           :', OnDevice ( )
+  print*, ''
+  
+  UseDevice = .true.
+  print*, 'UseDevice              :', UseDevice
+  print*, 'OnDevice ( UseDevice ) :', OnDevice ( UseDevice )
+  print*, ''
+  
+  UseDevice = .false.
+  print*, 'UseDevice              :', UseDevice
+  print*, 'OnDevice ( UseDevice ) :', OnDevice ( UseDevice ) 
+  print*, ''
     
-  allocate ( A ( 1024 ) )
-  allocate ( B ( 1024 ) )
-  allocate ( C ( 1024 ) )
+  
+  allocate ( A ( 1024*10 ) )
+  allocate ( B ( 1024*10 ) )
+  allocate ( C ( 1024*10 ) )
+  allocate ( C_Ref, source = C )
   
   call random_number ( A )
   call random_number ( B )
-  call random_number ( C )
   
-  !$OMP metadirective &
-  !$OMP   when ( user = { condition ( UseDevice > 0 ) }  : target )
+  C_Ref = A + B 
+    
+  
+  print*, 'Calling ComputeAndTimeVectorAddition on Host'
+  C = 0.0_real64
+  UseDevice = .false.
+  call ComputeAndTimeVectorAddition &
+         ( A, B, C, Timing, UseDeviceOption = UseDevice )
+  print*, 'Timing on host         :', Timing
+  print*, 'Correct results        :', all ( C == C_Ref )
+  print*, ''
+  
+  print*, 'Calling ComputeAndTimeVectorAddition on Device'
+  C = 0.0_real64
+  UseDevice = .true.
+  call ComputeAndTimeVectorAddition &
+         ( A, B, C, Timing, UseDeviceOption = UseDevice )
+  print*, 'Timing on device       :', Timing
+  print*, 'Correct results        :', all ( C == C_Ref )
+  print*, ''
+  
+  
+contains
+
+  
+  function OnDevice ( UseDeviceOption ) result ( OD )
+  
+    logical, intent ( in ), optional :: &
+      UseDeviceOption
+    logical :: &
+      OD
+      
+    logical :: &
+      UseDevice
+      
+    UseDevice = .true.
+    if ( present ( UseDeviceOption ) ) &
+      UseDevice = UseDeviceOption
+    
+    !$OMP begin metadirective &
+    !$OMP   when ( user = { condition ( UseDevice .EQV. .true. ) } &
+    !$OMP     : target map ( tofrom : OD ) )
+    OD = .not. omp_is_initial_device()
+    !$OMP end metadirective
+    
+  end function OnDevice 
+    
+  
+  subroutine ComputeAndTimeVectorAddition ( A, B, C, Timing, UseDeviceOption )
+      
+    real ( real64 ), dimension ( : ), intent ( in ) :: &
+      A, B
+    real ( real64 ), dimension ( : ), intent ( out ) :: &
+      C
+    real ( real64 ), intent ( out ) :: &
+      Timing
+    logical, intent ( in ), optional :: &
+      UseDeviceOption
+    
+    integer :: &
+      iV
+    real ( real64 ) :: &
+      Start
+    logical :: &
+      UseDevice
+      
+    UseDevice = .true.
+    if ( present ( UseDeviceOption ) ) &
+      UseDevice = UseDeviceOption
+      
+    if ( UseDevice ) then
+      !$OMP target enter data map ( to : A, B )
+      !$OMP target enter data map ( alloc: C )
+    end if
+    
+    Start = omp_get_wtime ( )
+    
+    !$OMP begin metadirective &
+    !$OMP   when ( user = { condition ( UseDevice .EQV. .true. ) } &
+    !$OMP     : target teams distribute )
+    
+    !$OMP parallel do
+    do iV = 1, size ( A )
+      C ( iV ) = A ( iV ) + B ( iV )
+    end do
+    !$OMP end parallel do
+    
+    !$OMP end metadirective
+    
+    Timing = omp_get_wtime ( ) - Start
+    
+    if ( UseDevice ) then
+      !$OMP target exit data map ( from : C )
+      !$OMP target exit data map ( delete: A, B, C )
+    end if
+  
+  end subroutine ComputeAndTimeVectorAddition
   
-  !$OMP parallel do
-  do iV = 1, size ( A )
-    C ( iV ) = A ( iV ) + B ( iV )
-  end do
   
-end program OpenMP_metadirective_target_test
+end program OpenMP_metadirective_user_condition_target_test