Dependence graph: refactor function-call control dependency branching

Avoid a nested if when the top-level else and the inner if branch will
execute the same code. There is substantial white-space change in this
commit for it removes one level of indentation. No changes in behaviour
intended.

Author: tautschnig

src/analyses/dependence_graph.cpp

@@ -233,36 +233,29 @@ void dep_graph_domaint::transform(
   control_deps = std::move(filtered_control_deps);
 
   // propagate control dependencies across function calls
-  if(from->is_function_call())
+  if(from->is_function_call() && function_from != function_to)
   {
-    if(function_from == function_to)
-    {
-      control_dependencies(function_from, from, to, *dep_graph);
-    }
-    else
-    {
-      // edge to function entry point
-      const goto_programt::const_targett next = std::next(from);
+    // edge to function entry point
+    const goto_programt::const_targett next = std::next(from);
 
-      dep_graph_domaint *s=
-        dynamic_cast<dep_graph_domaint*>(&(dep_graph->get_state(next)));
-      assert(s!=nullptr);
+    dep_graph_domaint *s =
+      dynamic_cast<dep_graph_domaint *>(&(dep_graph->get_state(next)));
+    CHECK_RETURN(s != nullptr);
 
-      if(s->is_bottom())
-      {
-        s->has_values = tvt::unknown();
-        s->has_changed = true;
-      }
+    if(s->is_bottom())
+    {
+      s->has_values = tvt::unknown();
+      s->has_changed = true;
+    }
 
-      s->has_changed |= util_inplace_set_union(s->control_deps, control_deps);
-      s->has_changed |= util_inplace_set_union(
-        s->control_dep_candidates, control_dep_candidates);
+    s->has_changed |= util_inplace_set_union(s->control_deps, control_deps);
+    s->has_changed |=
+      util_inplace_set_union(s->control_dep_candidates, control_dep_candidates);
 
-      control_deps.clear();
-      control_deps.insert(from);
+    control_deps.clear();
+    control_deps.insert(from);
 
-      control_dep_candidates.clear();
-    }
+    control_dep_candidates.clear();
   }
   else
     control_dependencies(function_from, from, to, *dep_graph);