From 67535711e8d86a975ff9aac9c2d2fdad24ec5915 Mon Sep 17 00:00:00 2001
From: Marco Costalba <mcostalba@gmail.com>
Date: Wed, 11 Feb 2009 12:13:58 +0100
Subject: [PATCH] generate_evasions() avoid to calculate pinned pieces

Pass as function argument.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---
 src/movegen.cpp  | 12 +++++-------
 src/movegen.h    |  2 +-
 src/movepick.cpp |  2 +-
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 4bb2a7f7..f30d4572 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -204,7 +204,7 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
 /// only legal moves.  It returns the number of generated moves. This
 /// function is very ugly, and needs cleaning up some time later.  FIXME
 
-int generate_evasions(const Position& pos, MoveStack* mlist) {
+int generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
 
   assert(pos.is_ok());
   assert(pos.is_check());
@@ -265,12 +265,10 @@ int generate_evasions(const Position& pos, MoveStack* mlist) {
   if (!(checkers & (checkers - 1))) // Only one bit set?
   {
       Square checksq = first_1(checkers);
+      Bitboard not_pinned = ~pinned;
 
       assert(pos.color_of_piece_on(checksq) == them);
 
-      // Find pinned pieces
-      Bitboard not_pinned = ~pos.pinned_pieces(us);
-
       // Generate captures of the checking piece
 
       // Pawn captures
@@ -361,15 +359,15 @@ int generate_legal_moves(const Position& pos, MoveStack* mlist) {
 
   assert(pos.is_ok());
 
+  Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+
   if (pos.is_check())
-      return generate_evasions(pos, mlist);
+      return generate_evasions(pos, mlist, pinned);
 
   // Generate pseudo-legal moves
   int n = generate_captures(pos, mlist);
   n += generate_noncaptures(pos, mlist + n);
 
-  Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
-
   // Remove illegal moves from the list
   for (int i = 0; i < n; i++)
       if (!pos.pl_move_is_legal(mlist[i].move, pinned))
diff --git a/src/movegen.h b/src/movegen.h
index 034dd389..48e0dec0 100644
--- a/src/movegen.h
+++ b/src/movegen.h
@@ -35,7 +35,7 @@
 extern int generate_captures(const Position &pos, MoveStack *mlist);
 extern int generate_noncaptures(const Position &pos, MoveStack *mlist);
 extern int generate_checks(const Position &pos, MoveStack *mlist, Bitboard dc);
-extern int generate_evasions(const Position &pos, MoveStack *mlist);
+extern int generate_evasions(const Position &pos, MoveStack *mlist, Bitboard pinned);
 extern int generate_legal_moves(const Position &pos, MoveStack *mlist);
 extern bool move_is_legal(const Position &pos, const Move m, Bitboard pinned);
 
diff --git a/src/movepick.cpp b/src/movepick.cpp
index eb57f78a..67143070 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -162,7 +162,7 @@ Move MovePicker::get_next_move() {
 
     case PH_EVASIONS:
         assert(pos.is_check());
-        numOfMoves = generate_evasions(pos, moves);
+        numOfMoves = generate_evasions(pos, moves, pinned);
         score_evasions();
         movesPicked = 0;
         break;
-- 
2.39.2