Call vectorised version of runner_doself2_force.

src/runner.c

@@ -1787,8 +1787,13 @@ void *runner_main(void *data) {
           else if (t->subtype == task_subtype_gradient)
             runner_doself1_gradient(r, ci);
 #endif
-          else if (t->subtype == task_subtype_force)
+          else if (t->subtype == task_subtype_force) {
+#if defined(WITH_VECTORIZATION) && defined(GADGET2_SPH)
+            runner_doself2_force_vec(r, ci);
+#else
             runner_doself2_force(r, ci);
+#endif
+          }
           else if (t->subtype == task_subtype_grav)
             runner_doself_grav(r, ci, 1);
           else if (t->subtype == task_subtype_external_grav)

src/runner_doiact.h

@@ -2633,9 +2633,14 @@ void DOSUB_SELF2(struct runner *r, struct cell *ci, int gettimer) {
   }
 
   /* Otherwise, compute self-interaction. */
-  else
+  else {
+#if (DOSELF2 == runner_doself2_force) && defined(WITH_VECTORIZATION) && \
+    defined(GADGET2_SPH)
+    runner_doself2_force_vec(r, ci);
+#else
     DOSELF2(r, ci);
-
+#endif
+  }
   if (gettimer) TIMER_TOC(TIMER_DOSUB_SELF);
 }