perf(board): making hashing use incremental XORs instead of rebuild from scratch

1 files changed, 3 insertions, 5 deletions

diff --git a/src/bot.cpp b/src/bot.cpp
index e9b0b4d..969606e 100644
--- a/src/bot.cpp
+++ b/src/bot.cpp
@@ -171,14 +171,12 @@ static int search(int depth, Game *b, int alpha, int beta, int ply) {
       return 0;
     }
   }
-  const uint64_t gameHash = GenerateZobristKey(b);
-
-  if (isRepetionDraw(gameHash, b)) {
+  if (isRepetionDraw(b->hash, b)) {
     return 0;
   };
 
   TranspositionsEntry *entry = nullptr;
-  if (auto it = b->Transpositions->find(gameHash);
+  if (auto it = b->Transpositions->find(b->hash);
       it != b->Transpositions->end()) {
     entry = &it->second;
     if (entry->depth >= depth) {
@@ -241,7 +239,7 @@ static int search(int depth, Game *b, int alpha, int beta, int ply) {
       flag = UPPERBOUND;
     }
 
-    (*b->Transpositions)[gameHash] = {
+    (*b->Transpositions)[b->hash] = {
         .depth = depth, .Eval = bestScore, .flag = flag, .bestMove = bestMove};
   }
   return bestScore;