Small cleanups

[stockfish] / src / movegen.cpp

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 4c609352358cbbf797aa8b0805dbc1e98e7b7e56..9964ad343b8b656a6888938db3e17bed13c2ccc6 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -52,14 +52,14 @@ namespace {
   template<Color Us, GenType Type>
   ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
 
-    // Compute some compile time parameters relative to the white side
     constexpr Color     Them     = (Us == WHITE ? BLACK      : WHITE);
     constexpr Bitboard  TRank7BB = (Us == WHITE ? Rank7BB    : Rank2BB);
     constexpr Bitboard  TRank3BB = (Us == WHITE ? Rank3BB    : Rank6BB);
-    constexpr Direction Up       = (Us == WHITE ? NORTH      : SOUTH);
+    constexpr Direction Up       = pawn_push(Us);
     constexpr Direction UpRight  = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
     constexpr Direction UpLeft   = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
 
+    const Square ksq = pos.square<KING>(Them);
     Bitboard emptySquares;
 
     Bitboard pawnsOn7    = pos.pieces(Us, PAWN) &  TRank7BB;
@@ -84,8 +84,6 @@ namespace {
 
         if (Type == QUIET_CHECKS)
         {
-            Square ksq = pos.square<KING>(Them);
-
             b1 &= pos.attacks_from<PAWN>(ksq, Them);
             b2 &= pos.attacks_from<PAWN>(ksq, Them);
 
@@ -130,8 +128,6 @@ namespace {
         Bitboard b2 = shift<UpLeft >(pawnsOn7) & enemies;
         Bitboard b3 = shift<Up     >(pawnsOn7) & emptySquares;
 
-        Square ksq = pos.square<KING>(Them);
-
         while (b1)
             moveList = make_promotions<Type, UpRight>(moveList, pop_lsb(&b1), ksq);
 
@@ -187,7 +183,7 @@ namespace {
   ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
                           Bitboard target) {
 
-    assert(Pt != KING && Pt != PAWN);
+    static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
 
     const Square* pl = pos.squares<Pt>(us);
 
@@ -218,9 +214,6 @@ namespace {
 
   template<Color Us, GenType Type>
   ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) {
-
-    constexpr CastlingRight OO  = Us | KING_SIDE;
-    constexpr CastlingRight OOO = Us | QUEEN_SIDE;
     constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantations
 
     moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
@@ -236,14 +229,10 @@ namespace {
         while (b)
             *moveList++ = make_move(ksq, pop_lsb(&b));
 
-        if (Type != CAPTURES && pos.can_castle(CastlingRight(OO | OOO)))
-        {
-            if (!pos.castling_impeded(OO) && pos.can_castle(OO))
-                *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OO));
-
-            if (!pos.castling_impeded(OOO) && pos.can_castle(OOO))
-                *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OOO));
-        }
+        if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING))
+            for(CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } )
+                if (!pos.castling_impeded(cr) && pos.can_castle(cr))
+                    *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(cr));
     }
 
     return moveList;
@@ -261,7 +250,7 @@ namespace {
 template<GenType Type>
 ExtMove* generate(const Position& pos, ExtMove* moveList) {
 
-  assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
+  static_assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS, "Unsupported type in generate()");
   assert(!pos.checkers());
 
   Color us = pos.side_to_move();