SCC: Add logging of vector-within-seq markers, which indicate issues

transformations/transformations/single_column_coalesced.py

@@ -366,6 +366,12 @@ def kernel_annotate_sequential_loops_openacc(cls, routine, horizontal):
                     # Perform pragma addition in place to avoid nested loop replacements
                     loop._update(pragma=(ir.Pragma(keyword='acc', content='loop seq'),))
 
+                # Warn if we detect vector insisde sequential loop nesting
+                nested_loops = FindNodes(ir.Loop).visit(loop.body)
+                loop_pragmas = flatten(as_tuple(l.pragma) for l in as_tuple(nested_loops))
+                if any('loop vector' in pragma.content for pragma in loop_pragmas):
+                    info(f'[Loki-SCC::Annotate] Detected vector loop in sequential loop in {routine.name}')
+
     @classmethod
     def kernel_annotate_subroutine_present_openacc(cls, routine):
         """
@@ -389,12 +395,12 @@ def kernel_annotate_subroutine_present_openacc(cls, routine):
     @classmethod
     def insert_annotations(cls, routine, horizontal, vertical, hoist_column_arrays):
 
-        # Mark all non-parallel loops as `!$acc loop seq`
-        cls.kernel_annotate_sequential_loops_openacc(routine, horizontal)
-
         # Mark all parallel vector loops as `!$acc loop vector`
         cls.kernel_annotate_vector_loops_openacc(routine, horizontal, vertical)
 
+        # Mark all non-parallel loops as `!$acc loop seq`
+        cls.kernel_annotate_sequential_loops_openacc(routine, horizontal)
+
         # Wrap the routine body in `!$acc data present` markers
         # to ensure device-resident data is used for array and struct arguments.
         cls.kernel_annotate_subroutine_present_openacc(routine)