Improve the interface of the gravity cache construction.

src/gravity/Default/gravity.h

@@ -41,6 +41,7 @@ __attribute__((always_inline)) INLINE static float gravity_get_mass(
  * @brief Returns the softening of a particle
  *
  * @param gp The particle of interest
+ * @param grav_props The global gravity properties.
  */
 __attribute__((always_inline)) INLINE static float gravity_get_softening(
     const struct gpart* gp, const struct gravity_props* restrict grav_props) {

src/gravity_cache.h

@@ -149,15 +149,17 @@ static INLINE void gravity_cache_init(struct gravity_cache *c, int count) {
  * @param shift A shift to apply to all the particles.
  * @param CoM The position of the multipole.
  * @param r_max2 The square of the multipole radius.
- * @param theta_crit2 The square of the opening angle.
  * @param cell The cell we play with (to get reasonable padding positions).
+ * @param grav_props The global gravity properties.
  */
 __attribute__((always_inline)) INLINE static void gravity_cache_populate(
     timebin_t max_active_bin, struct gravity_cache *c,
     const struct gpart *restrict gparts, int gcount, int gcount_padded,
-    const double shift[3], const float CoM[3], float r_max2, float theta_crit2,
+    const double shift[3], const float CoM[3], float r_max2,
     const struct cell *cell, const struct gravity_props *grav_props) {
 
+  const float theta_crit2 = grav_props->theta_crit2;
+
   /* Make the compiler understand we are in happy vectorization land */
   swift_declare_aligned_ptr(float, x, c->x, SWIFT_CACHE_ALIGNMENT);
   swift_declare_aligned_ptr(float, y, c->y, SWIFT_CACHE_ALIGNMENT);
@@ -220,6 +222,7 @@ __attribute__((always_inline)) INLINE static void gravity_cache_populate(
  * multiple of the vector length.
  * @param shift A shift to apply to all the particles.
  * @param cell The cell we play with (to get reasonable padding positions).
+ * @param grav_props The global gravity properties.
  */
 __attribute__((always_inline)) INLINE static void
 gravity_cache_populate_no_mpole(timebin_t max_active_bin,

src/runner_doiact_grav.h

@@ -466,7 +466,6 @@ static INLINE void runner_dopair_grav_pp(struct runner *r, struct cell *ci,
   struct space *s = e->s;
   const int periodic = s->periodic;
   const double cell_width = s->width[0];
-  const float theta_crit2 = e->gravity_properties->theta_crit2;
   const double a_smooth = e->gravity_properties->a_smooth;
   const double r_cut_min = e->gravity_properties->r_cut_min;
   const double rlr = cell_width * a_smooth;
@@ -532,11 +531,11 @@ static INLINE void runner_dopair_grav_pp(struct runner *r, struct cell *ci,
 
   /* Fill the caches */
   gravity_cache_populate(e->max_active_bin, ci_cache, ci->gparts, gcount_i,
-                         gcount_padded_i, shift_i, CoM_j, rmax2_j, theta_crit2,
-                         ci, e->gravity_properties);
+                         gcount_padded_i, shift_i, CoM_j, rmax2_j, ci,
+                         e->gravity_properties);
   gravity_cache_populate(e->max_active_bin, cj_cache, cj->gparts, gcount_j,
-                         gcount_padded_j, shift_j, CoM_i, rmax2_i, theta_crit2,
-                         cj, e->gravity_properties);
+                         gcount_padded_j, shift_j, CoM_i, rmax2_i, cj,
+                         e->gravity_properties);
 
   /* Can we use the Newtonian version or do we need the truncated one ? */
   if (!periodic) {