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Retire Material::space_weight()

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Move all in evaluation.

Simplify the code and concentrate in a single place
all the logic behind space evaluation, making it much
more clear.

Verified also at STC it does not regress due to a possible
slow down:

LLR: 3.91 (-2.94,2.94) [-3.00,1.00]
Total: 65744 W: 13285 L: 13194 D: 39265

No functional change.
This commit is contained in:
Marco Costalba
2014-12-31 10:41:20 +01:00
parent 2416242c96
commit 4c9b423161
3 changed files with 13 additions and 23 deletions
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25
src/evaluate.cpp
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@@ -635,10 +635,10 @@ namespace {
// space evaluation is a simple bonus based on the number of safe squares
// available for minor pieces on the central four files on ranks 2--4. Safe
// squares one, two or three squares behind a friendly pawn are counted
// twice. Finally, the space bonus is scaled by a weight taken from the
// material hash table. The aim is to improve play on game opening.
// twice. Finally, the space bonus is multiplied by a weight. The aim is to
// improve play on game opening.
template<Color Us>
Score evaluate_space(const Position& pos, const EvalInfo& ei, Score weight) {
Score evaluate_space(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
@@ -659,7 +659,11 @@ namespace {
assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
// Count safe + (behind & safe) with a single popcount
return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)) * weight;
int bonus = popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
int weight = pos.count<KNIGHT>(Us) + pos.count<BISHOP>(Us)
+ pos.count<KNIGHT>(Them) + pos.count<BISHOP>(Them);
return make_score(bonus * weight * weight, 0);
}
@@ -731,12 +735,10 @@ namespace {
score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable;
}
// Evaluate space for both sides, only in middlegame
if (ei.mi->space_weight())
// Evaluate space for both sides, only during opening
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
{
Score s = evaluate_space<WHITE>(pos, ei, ei.mi->space_weight())
- evaluate_space<BLACK>(pos, ei, ei.mi->space_weight());
Score s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
score += apply_weight(s, Weights[Space]);
}
@@ -784,9 +786,8 @@ namespace {
Tracing::write(PAWN, ei.pi->pawns_score());
Tracing::write(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
, apply_weight(mobility[BLACK], Weights[Mobility]));
Score w = evaluate_space<WHITE>(pos, ei, ei.mi->space_weight());
Score b = evaluate_space<BLACK>(pos, ei, ei.mi->space_weight());
Tracing::write(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
Tracing::write(Tracing::SPACE, apply_weight(evaluate_space<WHITE>(pos, ei), Weights[Space])
, apply_weight(evaluate_space<BLACK>(pos, ei), Weights[Space]));
Tracing::write(Tracing::TOTAL, score);
Tracing::ei = ei;
Tracing::sf = sf;