diff --git a/src/cell.c b/src/cell.c
index 8bd26b32343f2307673c5f0d9c3abfd68172c187..66f7453667e202494515e0eb45ab7028e75a8303 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -1386,12 +1386,14 @@ void cell_check_sort_flags(const struct cell *c) {
const int do_stars_sub_sort = cell_get_flag(c, cell_flag_do_stars_sub_sort);
if (do_hydro_sub_sort)
- error("cell %d has a hydro sub_sort flag set. Node=%d depth=%d maxdepth=%d",
- c->cellID, c->nodeID, c->depth, c->maxdepth);
+ error(
+ "cell %lld has a hydro sub_sort flag set. Node=%d depth=%d maxdepth=%d",
+ c->cellID, c->nodeID, c->depth, c->maxdepth);
if (do_stars_sub_sort)
- error("cell %d has a stars sub_sort flag set. Node=%d depth=%d maxdepth=%d",
- c->cellID, c->nodeID, c->depth, c->maxdepth);
+ error(
+ "cell %lld has a stars sub_sort flag set. Node=%d depth=%d maxdepth=%d",
+ c->cellID, c->nodeID, c->depth, c->maxdepth);
if (c->split) {
for (int k = 0; k < 8; ++k) {
diff --git a/src/cell.h b/src/cell.h
index d80d11b8229032795a64b2c862d3dc0bc310de70..b6d9bb9ad66ca30bbd55839d59f40986d404e224 100644
--- a/src/cell.h
+++ b/src/cell.h
@@ -62,6 +62,11 @@ struct scheduler;
/* Global variables. */
extern int cell_next_tag;
+/*! Counter for cell IDs (when exceeding max values for uniqueness) */
+#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
+extern long long last_cell_id;
+#endif
+
/* Struct to temporarily buffer the particle locations and bin id. */
struct cell_buff {
double x[3];
@@ -225,7 +230,7 @@ struct pcell {
#ifdef SWIFT_DEBUG_CHECKS
/* Cell ID (for debugging) */
- int cellID;
+ long long cellID;
#endif
} SWIFT_STRUCT_ALIGN;
@@ -452,7 +457,7 @@ struct cell {
#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
/* Cell ID (for debugging) */
- int cellID;
+ long long cellID;
#endif
#ifdef SWIFT_DEBUG_CHECKS
@@ -1279,4 +1284,95 @@ __attribute__((always_inline)) INLINE static struct task *cell_get_recv(
#endif
}
+/**
+ * @brief Generate the cell ID for top level cells. Only used for debugging.
+ *
+ * Cell IDs are stored in the long long `cell->cellID`. Top level cells get
+ * their index according to their location on the top level grid, and are
+ * marked with a minus sign.
+ * We have 15 bits set aside in `cell->cellID` for the top level cells. Hence
+ * if we have more that 32^3 top level cells, the cell IDs won't be guaranteed
+ * to be unique. Top level cells will still be recognizable by the minus sign.
+ */
+__attribute__((always_inline)) INLINE void cell_assign_top_level_cell_index(
+ struct cell *c, int cdim[3], double dim[3], double width[3]) {
+
+#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
+ if (c->depth != 0) {
+ error("assigning top level cell index to cell with depth > 0");
+ } else {
+ if (cdim[0] * cdim[1] * cdim[2] > 32 * 32 * 32) {
+ /* print warning only once */
+ if (last_cell_id == 1) {
+ message(
+ "Warning: Got %d x %d x %d top level cells."
+ "Cell IDs are only guaranteed to be unique if count is < 32^3",
+ cdim[0], cdim[1], cdim[2]);
+ }
+ c->cellID = -last_cell_id;
+ atomic_inc(&last_cell_id);
+ }
+
+ int i = (int)(c->loc[0] / width[0]);
+ int j = (int)(c->loc[1] / width[1]);
+ int k = (int)(c->loc[2] / width[2]);
+ c->cellID = -(long long)(cell_getid(cdim, i, j, k) + 1);
+ }
+#endif
+}
+
+/**
+ * @brief Generate the cell ID for progeny cells. Only used for debugging.
+ *
+ * Cell IDs are stored in the long long `cell->cellID`.
+ * We have 15 bits set aside in `cell->cellID` for the top level cells, and
+ * one for a minus sign to mark top level cells. The remaining 48 bits are
+ * for all other cells. Each progeny cell gets a unique ID by inheriting
+ * its parent ID and adding 3 bits on the right side, which are set according
+ * to the progeny's location within its parent cell. Hence we can store up to
+ * 16 levels of depth uniquely.
+ * If the depth exceeds 16, we use the old scheme where we just add up a
+ * counter. This gives us 32^3 new unique cell IDs, previously reserved for
+ * top level cells, but the IDs won't be thread safe and will vary each run.
+ * After the 32^3 cells are filled, we reach degeneracy.
+ */
+__attribute__((always_inline)) INLINE void cell_assign_cell_index(
+ struct cell *c, const struct cell *parent) {
+
+#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
+ if (c->depth == 0) {
+ error("assigning progeny cell index to top level cell.");
+ } else if (c->depth > 16 || last_cell_id > 1) {
+ /* last_cell_id > 1 => too many top level cells for clever IDs */
+ /* print warning only once */
+ if (last_cell_id == 1) {
+ message(
+ "Warning: Got depth %d > 16."
+ "IDs are only guaranteed unique if depth <= 16",
+ c->depth);
+ }
+ c->cellID = last_cell_id;
+ atomic_inc(&last_cell_id);
+ } else {
+ /* we're good to go for unique IDs */
+ /* first inherit the parent's ID and mark it as not top-level*/
+ long long child_id = llabs(parent->cellID);
+
+ /* make place for new bits */
+ /* parent's ID needs to be leading bits, so 000 children still
+ * change the value of the cellID */
+ child_id <<= 3;
+
+ /* get progeny index in parent cell */
+ if (c->loc[0] > parent->loc[0]) child_id |= 1LL;
+ if (c->loc[1] > parent->loc[1]) child_id |= 2LL;
+ if (c->loc[2] > parent->loc[2]) child_id |= 4LL;
+
+ /* add progeny index to cell index */
+ c->cellID = child_id;
+ }
+
+#endif
+}
+
#endif /* SWIFT_CELL_H */
diff --git a/src/runner_doiact_functions_stars.h b/src/runner_doiact_functions_stars.h
index 7e802d6f4afd885697c3915d475d38a4e5da7a73..b8bea6fa2125bbddb0deb013c46876e97ec61927 100644
--- a/src/runner_doiact_functions_stars.h
+++ b/src/runner_doiact_functions_stars.h
@@ -1098,7 +1098,7 @@ void DOSELF1_BRANCH_STARS(struct runner *r, struct cell *c) {
"ci->nodeID=%d d=%e sort_j[pjd].d=%e cj->" #TYPE \
".dx_max_sort=%e " \
"cj->" #TYPE \
- ".dx_max_sort_old=%e, cellID=%i super->cellID=%i" \
+ ".dx_max_sort_old=%e, cellID=%lld super->cellID=%lld" \
"cj->depth=%d cj->maxdepth=%d", \
cj->nodeID, ci->nodeID, d, sort_j[pjd].d, cj->TYPE.dx_max_sort, \
cj->TYPE.dx_max_sort_old, cj->cellID, cj->hydro.super->cellID, \
diff --git a/src/runner_others.c b/src/runner_others.c
index f684b1714f4eaad4d5c8b9c87c162d7f9ef89b21..479da517a7e435d91161ba4397d7acda9dbd76fe 100644
--- a/src/runner_others.c
+++ b/src/runner_others.c
@@ -313,7 +313,7 @@ void runner_do_star_formation(struct runner *r, struct cell *c, int timer) {
/* Did we get a star? (Or did we run out of spare ones?) */
if (sp != NULL) {
- /* message("We formed a star id=%lld cellID=%d", sp->id,
+ /* message("We formed a star id=%lld cellID=%lld", sp->id,
* c->cellID); */
/* Copy the properties of the gas particle to the star particle */
diff --git a/src/runner_time_integration.c b/src/runner_time_integration.c
index 656490bd3491a5166936af682623e6de668b28fc..db7f4a23ba743683137308680381ff86cc5608ba 100644
--- a/src/runner_time_integration.c
+++ b/src/runner_time_integration.c
@@ -1178,7 +1178,7 @@ void runner_do_limiter(struct runner *r, struct cell *c, int force,
/* Bip, bip, bip... wake-up time */
if (p->limiter_data.wakeup != time_bin_not_awake) {
- // message("Limiting particle %lld in cell %d", p->id, c->cellID);
+ // message("Limiting particle %lld in cell %lld", p->id, c->cellID);
/* Apply the limiter and get the new end of time-step */
const integertime_t ti_end_new = timestep_limit_part(p, xp, e);
diff --git a/src/space.c b/src/space.c
index 6747524f4fc0c33d5eb9b0392ba88cb8a85a78ae..5a5e11e541d599589a352aa0b32cb6564b474fad 100644
--- a/src/space.c
+++ b/src/space.c
@@ -94,9 +94,9 @@ int engine_star_resort_task_depth = engine_star_resort_task_depth_default;
/*! Expected maximal number of strays received at a rebuild */
int space_expected_max_nr_strays = space_expected_max_nr_strays_default;
-/*! Counter for cell IDs (when debugging) */
+/*! Counter for cell IDs (when debugging + max vals for unique IDs exceeded) */
#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
-int last_cell_id;
+long long last_cell_id;
#endif
/**
@@ -2412,24 +2412,24 @@ void space_write_cell(const struct space *s, FILE *f, const struct cell *c) {
if (c == NULL) return;
/* Get parent ID */
- int parent = root_cell_id;
+ long long parent = root_cell_id;
if (c->parent != NULL) parent = c->parent->cellID;
/* Get super ID */
char superID[100] = "";
- if (c->super != NULL) sprintf(superID, "%i", c->super->cellID);
+ if (c->super != NULL) sprintf(superID, "%lld", c->super->cellID);
/* Get hydro super ID */
char hydro_superID[100] = "";
if (c->hydro.super != NULL)
- sprintf(hydro_superID, "%i", c->hydro.super->cellID);
+ sprintf(hydro_superID, "%lld", c->hydro.super->cellID);
/* Write line for current cell */
- fprintf(f, "%i,%i,%i,", c->cellID, parent, c->nodeID);
+ fprintf(f, "%lld,%lld,%i,", c->cellID, parent, c->nodeID);
fprintf(f, "%i,%i,%i,%s,%s,%g,%g,%g,%g,%g,%g, ", c->hydro.count,
c->stars.count, c->grav.count, superID, hydro_superID, c->loc[0],
c->loc[1], c->loc[2], c->width[0], c->width[1], c->width[2]);
- fprintf(f, "%g, %g %i %i\n", c->hydro.h_max, c->stars.h_max, c->depth,
+ fprintf(f, "%g, %g, %i, %i\n", c->hydro.h_max, c->stars.h_max, c->depth,
c->maxdepth);
/* Write children */
@@ -2466,9 +2466,9 @@ void space_write_cell_hierarchy(const struct space *s, int j) {
/* Write root data */
fprintf(f, "%i, ,-1,", root_id);
- fprintf(f, "%li,%li,%li, , , , , , , , , ", s->nr_parts, s->nr_sparts,
+ fprintf(f, "%li,%li,%li, , , , , , , , ,", s->nr_parts, s->nr_sparts,
s->nr_gparts);
- fprintf(f, ",\n");
+ fprintf(f, " , , ,\n");
}
/* Write all the top level cells (and their children) */
diff --git a/src/space_rebuild.c b/src/space_rebuild.c
index f456be124731830a7c91f65caca4d1517644d701..0b68ca2b0cf9cfaea16ba95908fa38cacff71a25 100644
--- a/src/space_rebuild.c
+++ b/src/space_rebuild.c
@@ -35,7 +35,7 @@ extern int space_expected_max_nr_strays;
/*! Counter for cell IDs (when debugging) */
#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
-extern int last_cell_id;
+extern long long last_cell_id;
#endif
/**
@@ -911,8 +911,7 @@ void space_rebuild(struct space *s, int repartitioned, int verbose) {
c->black_holes.ti_old_part = ti_current;
#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
- c->cellID = -last_cell_id;
- last_cell_id++;
+ cell_assign_top_level_cell_index(c, s->cdim, s->dim, s->width);
#endif
const int is_local = (c->nodeID == engine_rank);
diff --git a/src/space_regrid.c b/src/space_regrid.c
index b20a3b4894bf3ce6418cd288f74fe91cedc36ab7..035c3f92096ab16c9334c7e56e791bf06b53c528 100644
--- a/src/space_regrid.c
+++ b/src/space_regrid.c
@@ -30,11 +30,6 @@
#include "engine.h"
#include "scheduler.h"
-/*! Counter for cell IDs (when debugging) */
-#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
-extern int last_cell_id;
-#endif
-
/**
* @brief Re-build the top-level cell grid.
*
@@ -321,8 +316,7 @@ void space_regrid(struct space *s, int verbose) {
#endif // WITH_MPI
if (s->with_self_gravity) c->grav.multipole = &s->multipoles_top[cid];
#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
- c->cellID = -last_cell_id;
- last_cell_id++;
+ cell_assign_top_level_cell_index(c, s->cdim, s->dim, s->width);
#endif
}
diff --git a/src/space_split.c b/src/space_split.c
index 728c6f8984b3476bfc0729546059477c3d1f38cf..38d75ad48b3e10c21d7047bb6471f41ee16bd881 100644
--- a/src/space_split.c
+++ b/src/space_split.c
@@ -33,11 +33,6 @@
#include "star_formation_logger.h"
#include "threadpool.h"
-/*! Counter for cell IDs (when debugging) */
-#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
-extern int last_cell_id;
-#endif
-
/**
* @brief Recursively split a cell.
*
@@ -250,7 +245,7 @@ void space_split_recursive(struct space *s, struct cell *c,
cp->mpi.tag = -1;
#endif // WITH_MPI
#if defined(SWIFT_DEBUG_CHECKS) || defined(SWIFT_CELL_GRAPH)
- cp->cellID = last_cell_id++;
+ cell_assign_cell_index(cp, c);
#endif
}