X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=7ae1effd9487f036407f3429c8a5047ec6f52023;hp=6032f47f6294b385847716154fe145009dfb5604;hb=335dc2d0217fdca26886c357a7f9e3e85e7b8b50;hpb=759b3c79cf94d101163f646b1eb2a9f9c64293ab

diff --git a/src/bitboard.h b/src/bitboard.h
index 6032f47f..7ae1effd 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -107,22 +107,27 @@ extern Magic BishopMagics[SQUARE_NB];
 /// whether a given bit is set in a bitboard, and for setting and clearing bits.
 
 inline Bitboard operator&(Bitboard b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b & SquareBB[s];
 }
 
 inline Bitboard operator|(Bitboard b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b | SquareBB[s];
 }
 
 inline Bitboard operator^(Bitboard b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b ^ SquareBB[s];
 }
 
 inline Bitboard& operator|=(Bitboard& b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b |= SquareBB[s];
 }
 
 inline Bitboard& operator^=(Bitboard& b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b ^= SquareBB[s];
 }
 
@@ -165,8 +170,9 @@ constexpr Bitboard make_bitboard(Square s, Squares... squares) {
 template<Direction D>
 constexpr Bitboard shift(Bitboard b) {
   return  D == NORTH      ?  b             << 8 : D == SOUTH      ?  b             >> 8
-        : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == SOUTH_EAST ? (b & ~FileHBB) >> 7
-        : D == NORTH_WEST ? (b & ~FileABB) << 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9
+        : D == EAST       ? (b & ~FileHBB) << 1 : D == WEST       ? (b & ~FileABB) >> 1
+        : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == NORTH_WEST ? (b & ~FileABB) << 7
+        : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9
         : 0;
 }