perf: add ttable to quiescence

Huge performance boost!

1 files changed, 48 insertions, 7 deletions

diff --git a/src/grossmeister/search.rs b/src/grossmeister/search.rs
index 15cae3a..f56d97d 100644
--- a/src/grossmeister/search.rs
+++ b/src/grossmeister/search.rs
@@ -171,6 +171,24 @@ impl Grossmeister {
             return 0.0
         }
 
+        if let Some(transposition) = self.transposition() {
+            match transposition.node_type {
+                NodeType::PV | NodeType::Cut => {
+                    if transposition.score >= beta {
+                        return beta
+                    }
+                    if transposition.score > alpha {
+                        alpha = transposition.score
+                    }
+                }
+                NodeType::All => {
+                    if transposition.score <= alpha {
+                        return alpha
+                    }
+                }
+            }
+        }
+
         // Mate distance pruning
         let mating_score = Grossmeister::MDP(&mut alpha, &mut beta, root_distance);
         if mating_score != 0.0 {
@@ -208,10 +226,33 @@ impl Grossmeister {
                 self.board.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
 
                 if evaluation >= beta {
+                    self.store_transposition(TranspositionTableItem {
+                        hash: self.board.hash,
+                        mov: Some(mov),
+                        depth: 0,
+                        node_type: NodeType::Cut,
+                        score: beta,
+                    });
+
                     return beta; // Fail-hard beta-cutoff
                 }
                 if evaluation > alpha {
+                    self.store_transposition(TranspositionTableItem {
+                        hash: self.board.hash,
+                        mov: Some(mov),
+                        depth: 0,
+                        node_type: NodeType::PV,
+                        score: evaluation,
+                    });
                     alpha = evaluation;
+                } else {
+                    self.store_transposition(TranspositionTableItem {
+                        hash: self.board.hash,
+                        mov: None,
+                        depth: 0,
+                        node_type: NodeType::All,
+                        score: alpha,
+                    });
                 }
             } else {
                 self.board.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
@@ -225,8 +266,8 @@ impl Grossmeister {
         alpha
     }
 
-    fn reconstruct_pv(&mut self, depth: u8) -> Vec<Move> {
-        let mut pv = Vec::with_capacity(depth as usize);
+    fn reconstruct_pv(&mut self) -> Vec<Move> {
+        let mut pv = Vec::new();
 
         if let Some(transposition) = self.transposition() {
             if let Some(mov) = transposition.mov {
@@ -235,14 +276,14 @@ impl Grossmeister {
                 let hash_before = self.board.hash;
                 let captured = self.board.make_move(mov);
 
-                let mut subtree_pv = self.reconstruct_pv(depth - 1);
-                self.board.unmake_move(mov, captured, ep_target_before, castling_rights_before, hash_before);
-
                 pv.push(mov);
+                let mut subtree_pv = self.reconstruct_pv();
                 pv.append(&mut subtree_pv);
+
+                self.board.unmake_move(mov, captured, ep_target_before, castling_rights_before, hash_before);
+
             }
         }
-        debug_assert!(pv.len() == depth as usize);
         pv
     }
 
@@ -289,7 +330,7 @@ impl Grossmeister {
             }
 
             best_score = score;
-            pv = self.reconstruct_pv(depth);
+            pv = self.reconstruct_pv();
 
             // Print UCI info
             print!("info depth {} score ", depth);