From: Marco Costalba <mcostalba@gmail.com>
Date: Thu, 18 Sep 2008 08:51:24 +0000 (+0100)
Subject: MovePicker: simplify move swapping
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=52487c4f043024213c90f6f279d0479e90bce929

MovePicker: simplify move swapping

We don't need a full swap here because once found
and returned the best move will not be used again.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 6df070bb..235191af 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -335,10 +335,8 @@ Move MovePicker::pick_move_from_list() {
         }
       }
       if(bestIndex != -1) { // Found a good capture
-        MoveStack tmp = moves[movesPicked];
-        moves[movesPicked] = moves[bestIndex];
-        moves[bestIndex] = tmp;
-        move = moves[movesPicked++].move;
+        move = moves[bestIndex].move;
+        moves[bestIndex] = moves[movesPicked++];
         if(move != ttMove && move != mateKiller &&
            pos->move_is_legal(move, pinned))
           return move;
@@ -368,10 +366,8 @@ Move MovePicker::pick_move_from_list() {
         bestIndex = movesPicked;
 
       if(bestIndex != -1) {
-        MoveStack tmp = moves[movesPicked];
-        moves[movesPicked] = moves[bestIndex];
-        moves[bestIndex] = tmp;
-        move = moves[movesPicked++].move;
+        move = moves[bestIndex].move;
+        moves[bestIndex] = moves[movesPicked++];
         if(move != ttMove && move != mateKiller &&
            pos->move_is_legal(move, pinned))
           return move;
@@ -392,10 +388,8 @@ Move MovePicker::pick_move_from_list() {
         }
 
       if(bestIndex != -1) {
-        MoveStack tmp = moves[movesPicked];
-        moves[movesPicked] = moves[bestIndex];
-        moves[bestIndex] = tmp;
-        move = moves[movesPicked++].move;
+        move = moves[bestIndex].move;
+        moves[bestIndex] = moves[movesPicked++];
         return move;
       }
     }
@@ -431,11 +425,8 @@ Move MovePicker::pick_move_from_list() {
         bestIndex = movesPicked;
 
       if(bestIndex != -1) {
-        MoveStack tmp = moves[movesPicked];
-        moves[movesPicked] = moves[bestIndex];
-        moves[bestIndex] = tmp;
-
-        move = moves[movesPicked++].move;
+        move = moves[bestIndex].move;
+        moves[bestIndex] = moves[movesPicked++];
         // Remember to change the line below if we decide to hash the qsearch!
         // Maybe also postpone the legality check until after futility pruning?
         if(/* move != ttMove && */ pos->move_is_legal(move, pinned))