Fix parametrized direction in pawns generation

It worked by accident because we always called both directions,
but definition was wrong.

Functional change due to different generation order, but
perft numbers are the correct ones.

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

diff --git a/src/movegen.cpp b/src/movegen.cpp
index e0f3baacd5413fe238e5d5bb665137238725c6d4..c9255f31eb4e5245b867c0694d2d358a72dc77a0 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -406,8 +406,8 @@ namespace {
     const Bitboard TRank7BB  = (Us == WHITE ? Rank7BB  : Rank2BB);
     const Bitboard TRank3BB  = (Us == WHITE ? Rank3BB  : Rank6BB);
     const Square   UP        = (Us == WHITE ? DELTA_N  : DELTA_S);
-    const Square   RIGHT_UP  = (Us == WHITE ? DELTA_NE : DELTA_SE);
-    const Square   LEFT_UP   = (Us == WHITE ? DELTA_NW : DELTA_SW);
+    const Square   RIGHT_UP  = (Us == WHITE ? DELTA_NE : DELTA_SW);
+    const Square   LEFT_UP   = (Us == WHITE ? DELTA_NW : DELTA_SE);
 
     Square to;
     Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;