Fix and simplify move ordering

src/search/negamax.rs

@@ -6,7 +6,7 @@ use crate::{
 };
 
 use super::{
-    move_ordering,
+    move_ordering::score_move,
     quiescence::quiescence,
     time::{hard_limit, TimeInfo},
     transposition_table::TTEntry,
@@ -33,14 +33,14 @@ pub fn negamax(
         return Ok(q_score);
     }
 
-    let color = game.current_player();
-    let mut best_move = None;
-    let mut best_score = MIN_SCORE;
     let mut legal_moves = 0;
-    let all_moves = game.board.pseudo_moves_all();
-
+    let color = game.current_player();
+    let mut best_score = MIN_SCORE;
+    let mut best_move = None;
+    let mut moves = game.board.pseudo_moves_all();
     let tt_move = game.tt.lookup(game.hash).and_then(|entry| entry.mv);
-    let moves = move_ordering::sort_moves(all_moves, &game.mailbox, tt_move);
+
+    moves.sort_unstable_by_key(|mv| score_move(&game.mailbox, *mv, tt_move));
 
     for mv in moves {
         game.make_move(&mv);