return true;
struct hash_entry *phi_entry = _mesa_hash_table_search(b->phi_table, w);
- vtn_assert(phi_entry);
+
+ /* It's possible that this phi is in an unreachable block in which case it
+ * may never have been emitted and therefore may not be in the hash table.
+ * In this case, there's no var for it and it's safe to just bail.
+ */
+ if (phi_entry == NULL)
+ return true;
+
nir_variable *phi_var = phi_entry->data;
for (unsigned i = 3; i < count; i += 2) {