compiler: Polish ir.Relation

Author: FabioLuporini

devito/ir/support/basic.py

@@ -535,7 +535,7 @@ def function(self):
         if q_comp_acc(self.source.access) and not q_comp_acc(self.sink.access):
             # E.g., `source=ab[x].x` and `sink=ab[x]` -> `a(x)`
             return self.source.access.function_access
-        elif q_comp_acc(self.sink.access) and not q_comp_acc(self.source.access):
+        elif not q_comp_acc(self.source.access) and q_comp_acc(self.sink.access):
             # E.g., `source=ab[x]` and `sink=ab[x].y` -> `b(x)`
             return self.sink.access.function_access
         else: