- for (i = 0; i < bb->in_count; ++i) {
- in_bb = bb->in_bb [i];
-
- if (in_bb->last_seq_point) {
- int src_index = in_bb->last_seq_point->backend.size;
- int dst_index = ins->backend.size;
-
- /* bb->in_bb might contain duplicates */
- for (l = next [src_index]; l; l = l->next)
- if (GPOINTER_TO_UINT (l->data) == dst_index)
- break;
- if (!l)
- next [src_index] = g_slist_append (next [src_index], GUINT_TO_POINTER (dst_index));
- } else {
- /* Have to look at its predecessors */
- if (depth < 5)
- collect_pred_seq_points (in_bb, ins, next, depth + 1);
+ GArray *predecessors = g_array_new (FALSE, TRUE, sizeof (gpointer));
+ GHashTable *seen = g_hash_table_new_full (g_direct_hash, NULL, NULL, NULL);
+
+ // Insert/remove sentinel into the memoize table to detect loops containing bb
+ bb->pred_seq_points = MONO_SEQ_SEEN_LOOP;
+
+ for (int i = 0; i < bb->in_count; ++i) {
+ MonoBasicBlock *in_bb = bb->in_bb [i];
+
+ // This bb has the last seq point, append it and continue
+ if (in_bb->last_seq_point != NULL) {
+ predecessors = g_array_append_val (predecessors, in_bb->last_seq_point);
+ continue;
+ }
+
+ // We've looped or handled this before, exit early.
+ // No last sequence points to find.
+ if (in_bb->pred_seq_points == MONO_SEQ_SEEN_LOOP)
+ continue;
+
+ // Take sequence points from incoming basic blocks
+
+ if (in_bb == cfg->bb_entry)
+ continue;
+
+ if (in_bb->pred_seq_points == NULL)
+ recursively_make_pred_seq_points (cfg, in_bb);
+
+ // Union sequence points with incoming bb's
+ for (int i=0; i < in_bb->num_pred_seq_points; i++) {
+ if (!g_hash_table_lookup (seen, in_bb->pred_seq_points [i])) {
+ g_array_append_val (predecessors, in_bb->pred_seq_points [i]);
+ g_hash_table_insert (seen, in_bb->pred_seq_points [i], (gpointer)&MONO_SEQ_SEEN_LOOP);
+ }