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Simplify some obsolete code in king safety

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Now that QueenCheckBonus and friends are always > 0
we can remove a bunch of useless 'if' statements.

No functional change.
This commit is contained in:
Marco Costalba 2010-05-06 11:13:07 +02:00
parent 921bd87280
commit b14846b6d7
1 changed files with 30 additions and 48 deletions
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72
src/evaluate.cpp
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@ -216,7 +216,7 @@ namespace {
const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
// Bonuses for safe checks
// Bonuses for enemy's safe checks
const int QueenContactCheckBonus = 3;
const int DiscoveredCheckBonus = 3;
const int QueenCheckBonus = 2;
@ -705,16 +705,16 @@ namespace {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard undefended, attackedByOthers, escapeSquares, occ, b, b2, safe;
Bitboard undefended, attackedByOthers, escapeSquares, occ, b, b1, b2, safe;
Square from, to;
bool sente;
int attackUnits, count, shelter = 0;
const Square s = pos.king_square(Us);
const Square ksq = pos.king_square(Us);
// King shelter
if (relative_rank(Us, s) <= RANK_4)
if (relative_rank(Us, ksq) <= RANK_4)
{
shelter = ei.pi->get_king_shelter(pos, Us, s);
shelter = ei.pi->get_king_shelter(pos, Us, ksq);
ei.value += Sign[Us] * make_score(shelter, 0);
}
@ -742,7 +742,7 @@ namespace {
// king, and the quality of the pawn shelter.
attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
+ InitKingDanger[relative_square(Us, s)]
+ InitKingDanger[relative_square(Us, ksq)]
- (shelter >> 5);
// Analyse safe queen contact checks
@ -766,14 +766,14 @@ namespace {
// Is there a mate threat?
if (QueenContactMates && !pos.is_check())
{
escapeSquares = pos.attacks_from<KING>(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
escapeSquares = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
occ = pos.occupied_squares();
while (b)
{
to = pop_1st_bit(&b);
// Do we have escape squares from queen contact check attack ?
if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[ksq])))
{
// We have a mate, unless the queen is pinned or there
// is an X-ray attack through the queen.
@ -794,55 +794,37 @@ namespace {
}
}
// Analyse safe distance checks
// Analyse enemy's safe distance checks
safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us));
if (QueenCheckBonus > 0 || RookCheckBonus > 0)
{
b = pos.attacks_from<ROOK>(s) & safe;
b1 = pos.attacks_from<ROOK>(ksq) & safe;
b2 = pos.attacks_from<BISHOP>(ksq) & safe;
// Queen checks
b2 = b & ei.attacked_by(Them, QUEEN);
if (b2)
attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
// Enemy rooks safe checks
b = b1 & ei.attacked_by(Them, ROOK);
if (b)
attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b);
// Rook checks
b2 = b & ei.attacked_by(Them, ROOK);
if (b2)
attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b2);
}
if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
{
b = pos.attacks_from<BISHOP>(s) & safe;
// Enemy bishops safe checks
b = b2 & ei.attacked_by(Them, BISHOP);
if (b)
attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b);
// Queen checks
b2 = b & ei.attacked_by(Them, QUEEN);
if (b2)
attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
// Enemy queens safe checks
b = (b1 | b2) & ei.attacked_by(Them, QUEEN);
if (b)
attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b);
// Bishop checks
b2 = b & ei.attacked_by(Them, BISHOP);
if (b2)
attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b2);
}
if (KnightCheckBonus > 0)
{
b = pos.attacks_from<KNIGHT>(s) & safe;
// Knight checks
b2 = b & ei.attacked_by(Them, KNIGHT);
if (b2)
attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b2);
}
// Enemy knights safe checks
b = pos.attacks_from<KNIGHT>(ksq) & ei.attacked_by(Them, KNIGHT) & safe;
if (b)
attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
// Analyse discovered checks (only for non-pawns right now, consider
// adding pawns later).
if (DiscoveredCheckBonus)
{
b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
if (b)
attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
}
// Has a mate threat been found? We don't do anything here if the
// side with the mating move is the side to move, because in that