Small trivial clean-ups, February 2021

Closes https://github.com/official-stockfish/Stockfish/pull/3329

No functional change

src/Makefile

@@ -1,7 +1,5 @@
 # Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-# Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+# Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-# Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-# Copyright (C) 2015-2019 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

src/evaluate.cpp

@@ -423,7 +423,6 @@ namespace {
             score += BishopOnKingRing;
 
         int mob = popcount(b & mobilityArea[Us]);
-
         mobility[Us] += MobilityBonus[Pt - 2][mob];
 
         if (Pt == BISHOP || Pt == KNIGHT)

src/movepick.cpp

@@ -99,11 +99,11 @@ void MovePicker::score() {
   static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
 
   for (auto& m : *this)
-      if (Type == CAPTURES)
+      if constexpr (Type == CAPTURES)
           m.value =  int(PieceValue[MG][pos.piece_on(to_sq(m))]) * 6
                    + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
 
-      else if (Type == QUIETS)
+      else if constexpr (Type == QUIETS)
           m.value =      (*mainHistory)[pos.side_to_move()][from_to(m)]
                    + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
                    +     (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]

src/position.cpp

@@ -268,8 +268,8 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th
       enpassant = pawn_attacks_bb(~sideToMove, st->epSquare) & pieces(sideToMove, PAWN)
                && (pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove)))
                && !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove))))
-               && (file_of(square<KING>(sideToMove)) == file_of(st->epSquare)
+               && (   file_of(square<KING>(sideToMove)) == file_of(st->epSquare)
-               || !(blockers_for_king(sideToMove) & (st->epSquare + pawn_push(~sideToMove))));
+                   || !(blockers_for_king(sideToMove) & (st->epSquare + pawn_push(~sideToMove))));
   }
 
   // It's necessary for st->previous to be intialized in this way because legality check relies on its existence
@@ -518,8 +518,8 @@ bool Position::legal(Move m) const {
   // st->previous->blockersForKing consider capsq as empty.
   // If pinned, it has to move along the king ray.
   if (type_of(m) == EN_PASSANT)
-      return !(st->previous->blockersForKing[sideToMove] & from) ||
+      return   !(st->previous->blockersForKing[sideToMove] & from)
-               aligned(from, to, square<KING>(us));
+            || aligned(from, to, square<KING>(us));
 
   // Castling moves generation does not check if the castling path is clear of
   // enemy attacks, it is delayed at a later time: now!
@@ -546,8 +546,8 @@ bool Position::legal(Move m) const {
 
   // A non-king move is legal if and only if it is not pinned or it
   // is moving along the ray towards or away from the king.
-  return   !(blockers_for_king(us) & from)
+  return !(blockers_for_king(us) & from)
-        ||  aligned(from, to, square<KING>(us));
+      || aligned(from, to, square<KING>(us));
 }
 
 
@@ -657,8 +657,9 @@ bool Position::gives_check(Move m) const {
   // So the King must be in the same rank as fromsq to consider this possibility.
   // st->previous->blockersForKing consider capsq as empty.
   case EN_PASSANT:
-      return st->previous->checkersBB || (rank_of(square<KING>(~sideToMove)) == rank_of(from)
+      return st->previous->checkersBB
-          && st->previous->blockersForKing[~sideToMove] & from);
+          || (   rank_of(square<KING>(~sideToMove)) == rank_of(from)
+              && st->previous->blockersForKing[~sideToMove] & from);
 
   default: //CASTLING
   {

src/search.cpp

@@ -1181,7 +1181,7 @@ moves_loop: // When in check, search starts from here
               r++;
 
           // Decrease reduction if position is or has been on the PV
-          // and node is not likely to fail low (~10 Elo)
+          // and node is not likely to fail low. (~10 Elo)
           if (ss->ttPv && !likelyFailLow)
               r -= 2;