Add new function to decide on recursion with in a sub_pair task. Makes sure...

Add new function to decide on recursion with in a sub_pair task. Makes sure all recursion tests are identical.

src/cell.c

@@ -1316,6 +1316,19 @@ int cell_is_drift_needed(struct cell *c, const struct engine *e) {
   return 0;
 }
 
+/**
+ * @brief Can a task recurse to a lower level based on the staus of the particles
+ * in the cell.
+ *
+ * @param c The #cell.
+ */
+int cell_can_recurse_in_pair_task(const struct cell *c) {
+
+  return c->split &&
+         (2.f * kernel_gamma * space_stretch * (c->h_max_old + c->dx_max_old) <
+          c->dmin);
+}
+
 /**
  * @brief Traverse a sub-cell task and activate the sort tasks along the way.
  */
@@ -1353,13 +1366,8 @@ void cell_activate_subcell_tasks(struct cell *ci, struct cell *cj,
   }
 
   /* Otherwise, pair interation, recurse? */
-  else if (ci->split && cj->split &&
-           2.f * kernel_gamma * space_stretch *
-                   (ci->h_max_old + ci->dx_max_old) <
-               ci->dmin &&
-           2.f * kernel_gamma * space_stretch *
-                   (cj->h_max_old + cj->dx_max_old) <
-               cj->dmin) {
+  else if (cell_can_recurse_in_pair_task(ci) &&
+           cell_can_recurse_in_pair_task(cj)) {
 
     /* Get the type of pair if not specified explicitly. */
     double shift[3];

src/cell.h

@@ -388,5 +388,5 @@ void cell_check_timesteps(struct cell *c);
 void cell_store_pre_drift_values(struct cell *c);
 void cell_activate_subcell_tasks(struct cell *ci, struct cell *cj,
                                  struct scheduler *s);
-
+int cell_can_recurse_in_pair_task(const struct cell *c);
 #endif /* SWIFT_CELL_H */

src/runner_doiact.h

@@ -2096,11 +2096,7 @@ void DOSUB_PAIR1(struct runner *r, struct cell *ci, struct cell *cj, int sid,
   sid = space_getsid(s, &ci, &cj, shift);
 
   /* Recurse? */
-  if (ci->split && cj->split &&
-      2.f * kernel_gamma * space_stretch * (ci->h_max_old + ci->dx_max_old) <
-          ci->dmin &&
-      2.f * kernel_gamma * space_stretch * (cj->h_max_old + cj->dx_max_old) <
-          cj->dmin) {
+  if (cell_can_recurse_in_pair_task(ci) && cell_can_recurse_in_pair_task(cj)) {
 
     /* Different types of flags. */
     switch (sid) {
@@ -2395,11 +2391,7 @@ void DOSUB_PAIR2(struct runner *r, struct cell *ci, struct cell *cj, int sid,
   sid = space_getsid(s, &ci, &cj, shift);
 
   /* Recurse? */
-  if (ci->split && cj->split &&
-      2.f * kernel_gamma * space_stretch * (ci->h_max_old + ci->dx_max_old) <
-          ci->dmin &&
-      2.f * kernel_gamma * space_stretch * (cj->h_max_old + cj->dx_max_old) <
-          cj->dmin) {
+  if (cell_can_recurse_in_pair_task(ci) && cell_can_recurse_in_pair_task(cj)) {
 
     /* Different types of flags. */
     switch (sid) {
@@ -2706,11 +2698,8 @@ void DOSUB_SUBSET(struct runner *r, struct cell *ci, struct part *parts,
   else {
 
     /* Recurse? */
-    if (ci->split && cj->split &&
-        2.f * kernel_gamma * space_stretch * (ci->h_max_old + ci->dx_max_old) <
-            ci->dmin &&
-        2.f * kernel_gamma * space_stretch * (cj->h_max_old + cj->dx_max_old) <
-            cj->dmin) {
+    if (cell_can_recurse_in_pair_task(ci) &&
+        cell_can_recurse_in_pair_task(cj)) {
 
       /* Get the type of pair if not specified explicitly. */
       double shift[3] = {0.0, 0.0, 0.0};