Use self-describing constants instead of numbers

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 6923d20b31d8bbfdf87ac26c7bd36e3555b032f4..b4b8d9eea80b343a3647ab41f7e0d3ced5f4135d 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -30,34 +30,34 @@ namespace {
   #define S(mg, eg) make_score(mg, eg)
 
   // Doubled pawn penalty by opposed flag and file
-  const Score DoubledPawnPenalty[2][8] = {
+  const Score DoubledPawnPenalty[2][FILE_NB] = {
   { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
     S(23, 48), S(23, 48), S(20, 48), S(13, 43) },
   { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
     S(23, 48), S(23, 48), S(20, 48), S(13, 43) }};
 
   // Isolated pawn penalty by opposed flag and file
-  const Score IsolatedPawnPenalty[2][8] = {
+  const Score IsolatedPawnPenalty[2][FILE_NB] = {
   { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
     S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
   { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
     S(40, 35), S(40, 35), S(36, 35), S(25, 30) }};
 
   // Backward pawn penalty by opposed flag and file
-  const Score BackwardPawnPenalty[2][8] = {
+  const Score BackwardPawnPenalty[2][FILE_NB] = {
   { S(30, 42), S(43, 46), S(49, 46), S(49, 46),
     S(49, 46), S(49, 46), S(43, 46), S(30, 42) },
   { S(20, 28), S(29, 31), S(33, 31), S(33, 31),
     S(33, 31), S(33, 31), S(29, 31), S(20, 28) }};
 
   // Pawn chain membership bonus by file
-  const Score ChainBonus[8] = {
+  const Score ChainBonus[FILE_NB] = {
     S(11,-1), S(13,-1), S(13,-1), S(14,-1),
     S(14,-1), S(13,-1), S(13,-1), S(11,-1)
   };
 
   // Candidate passed pawn bonus by rank
-  const Score CandidateBonus[8] = {
+  const Score CandidateBonus[RANK_NB] = {
     S( 0, 0), S( 6, 13), S(6,13), S(14,29),
     S(34,68), S(83,166), S(0, 0), S( 0, 0)
   };
@@ -65,12 +65,12 @@ namespace {
   const Score PawnStructureWeight = S(233, 201);
 
   // Weakness of our pawn shelter in front of the king indexed by [king pawn][rank]
-  const Value ShelterWeakness[2][8] =
+  const Value ShelterWeakness[2][RANK_NB] =
   { { V(141), V(0), V(38), V(102), V(128), V(141), V(141) },
     { V( 61), V(0), V(16), V( 44), V( 56), V( 61), V( 61) } };
 
   // Danger of enemy pawns moving toward our king indexed by [pawn blocked][rank]
-  const Value StormDanger[2][8] =
+  const Value StormDanger[2][RANK_NB] =
   { { V(26), V(0), V(128), V(51), V(26) },
     { V(13), V(0), V( 64), V(25), V(13) } };
 
@@ -104,8 +104,8 @@ PawnEntry* PawnTable::probe(const Position& pos) {
   e->kingSquares[WHITE] = e->kingSquares[BLACK] = SQ_NONE;
   e->halfOpenFiles[WHITE] = e->halfOpenFiles[BLACK] = 0xFF;
 
-  Bitboard wPawns = pos.pieces(PAWN, WHITE);
-  Bitboard bPawns = pos.pieces(PAWN, BLACK);
+  Bitboard wPawns = pos.pieces(WHITE, PAWN);
+  Bitboard bPawns = pos.pieces(BLACK, PAWN);
   e->pawnAttacks[WHITE] = ((wPawns & ~FileHBB) << 9) | ((wPawns & ~FileABB) << 7);
   e->pawnAttacks[BLACK] = ((bPawns & ~FileHBB) >> 7) | ((bPawns & ~FileABB) >> 9);
 
@@ -240,12 +240,12 @@ Value PawnEntry::shelter_storm(const Position& pos, Square ksq) {
   {
       // Shelter penalty is higher for the pawn in front of the king
       b = ourPawns & FileBB[f];
-      rkUs = b ? rank_of(Us == WHITE ? first_1(b) : ~last_1(b)) : RANK_1;
+      rkUs = b ? rank_of(Us == WHITE ? lsb(b) : ~msb(b)) : RANK_1;
       safety -= ShelterWeakness[f != kf][rkUs];
 
       // Storm danger is smaller if enemy pawn is blocked
       b  = theirPawns & FileBB[f];
-      rkThem = b ? rank_of(Us == WHITE ? first_1(b) : ~last_1(b)) : RANK_1;
+      rkThem = b ? rank_of(Us == WHITE ? lsb(b) : ~msb(b)) : RANK_1;
       safety -= StormDanger[rkThem == rkUs + 1][rkThem];
   }
 
@@ -261,9 +261,14 @@ Score PawnEntry::update_safety(const Position& pos, Square ksq) {
 
   kingSquares[Us] = ksq;
   castleRights[Us] = pos.can_castle(Us);
+  minKPdistance[Us] = 0;
+
+  Bitboard pawns = pos.pieces(Us, PAWN);
+  if (pawns)
+      while (!(DistanceRingsBB[ksq][minKPdistance[Us]++] & pawns)) {}
 
   if (relative_rank(Us, ksq) > RANK_4)
-      return kingSafety[Us] = SCORE_ZERO;
+      return kingSafety[Us] = make_score(0, -16 * minKPdistance[Us]);
 
   Value bonus = shelter_storm<Us>(pos, ksq);
 
@@ -274,7 +279,7 @@ Score PawnEntry::update_safety(const Position& pos, Square ksq) {
   if (pos.can_castle(make_castle_right(Us, QUEEN_SIDE)))
       bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_C1)));
 
-  return kingSafety[Us] = make_score(bonus, 0);
+  return kingSafety[Us] = make_score(bonus, -16 * minKPdistance[Us]);
 }
 
 // Explicit template instantiation