phase A

1 files changed, 8 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
index 5ece480..61a3850 100644
--- a/src/main.c
+++ b/src/main.c
@@ -30,6 +30,14 @@ int main(int argc, char** argv) {
   threads_init(&engine_threads, ipc_state.uci_state.threads);
   threads_link(&engine_threads, &ipc_state);
 
+  // initialise the transposition table from the UCI "Hash" option (in MiB).
+  // pick the smallest power of two (>= 2^4) that fills at least that much memory.
+  size_t hash_mb = (size_t)ipc_state.uci_state.hash;
+  u64 buckets = (hash_mb * 1024 * 1024) / sizeof(tbucket_t);
+  int hash_log2 = 4;
+  while ((1ULL << (hash_log2 + 1)) <= buckets && hash_log2 < 30) hash_log2++;
+  ttable_init(&engine_threads.ttable, hash_log2);
+
   engine_messages_init(&ipc_state.engine_messages);
   goto skip_refresh;
 waiting_for_go: