feat: improve eval_move performance

1 files changed, 12 insertions, 9 deletions

diff --git a/src/board/engine.rs b/src/board/engine.rs
index 2ff3aed..47890ad 100644
--- a/src/board/engine.rs
+++ b/src/board/engine.rs
@@ -173,15 +173,18 @@ impl Board {
     /// Evaluate move for move ordering, prioritizing efficient captures
     /// where low-value pieces capture high-value pieces
     fn eval_move(&self, m: Move) -> f32 {
-        let [source_eval, target_eval] = [m.source, m.target]
-            .map(|sq| self.piece_by_square(sq))
-            .map(|p| {
-                match p {
-                    Some(p) => p.static_eval(),
-                    None => 0.,
-                }
-            });
-        2. * target_eval - source_eval
+        if m.kind == MoveKind::Capture || m.kind == MoveKind::EnPassant {
+            let [source_eval, target_eval] = [m.source, m.target]
+                .map(|sq| self.piece_by_square(sq))
+                .map(|p| {
+                    match p {
+                        Some(p) => p.static_eval(),
+                        None => 0.,
+                    }
+                });
+            return 2. * target_eval - source_eval
+        }
+        0.0
     }
 
     pub fn negamax_search(&mut self, mut alpha: f32, beta: f32, depth_left: u8, deadline: Instant) -> (f32, Vec<Move>) {