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Big reshuffle in evaluate.cpp

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Reshuffle functions to define them in reverse
calling order (C style).

This allow us to define templates before they are
used. Currently it is not like this, for instance
evaluate_pieces is defined after do_evaluate that
calls it. This happens to work for some strange
reason (two phase lookup?) but we want to avoid
code that works 'by magic'.

As a nice side-effect we can now remove the function
prototypes.

No functional change.
This commit is contained in:
Marco Costalba 2014-04-12 08:32:52 +02:00
parent 0510112f91
commit 2f92e3b525
1 changed files with 175 additions and 203 deletions
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378
src/evaluate.cpp
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@ -206,199 +206,37 @@ namespace {
// scores, indexed by color and by a calculated integer number.
Score KingDanger[COLOR_NB][128];
// Function prototypes
template<bool Trace>
Value do_evaluate(const Position& pos);
template<Color Us>
void init_eval_info(const Position& pos, EvalInfo& ei);
template<PieceType Pt, Color Us, bool Trace>
Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea);
template<Color Us, bool Trace>
Score evaluate_king(const Position& pos, const EvalInfo& ei);
template<Color Us, bool Trace>
Score evaluate_threats(const Position& pos, const EvalInfo& ei);
template<Color Us, bool Trace>
Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei);
template<Color Us>
int evaluate_space(const Position& pos, const EvalInfo& ei);
Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei);
Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
Score apply_weight(Score v, const Weight& w);
Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
}
namespace Eval {
/// evaluate() is the main evaluation function. It always computes two
/// values, an endgame score and a middlegame score, and interpolates
/// between them based on the remaining material.
Value evaluate(const Position& pos) {
return do_evaluate<false>(pos);
// apply_weight() weights score v by score w trying to prevent overflow
Score apply_weight(Score v, const Weight& w) {
return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256);
}
/// trace() is like evaluate(), but instead of returning a value, it returns
/// a string (suitable for outputting to stdout) that contains the detailed
/// descriptions and values of each evaluation term. It's mainly used for
/// debugging.
std::string trace(const Position& pos) {
return Tracing::do_trace(pos);
// weight_option() computes the value of an evaluation weight, by combining
// two UCI-configurable weights (midgame and endgame) with an internal weight.
Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
Weight w = { Options[mgOpt] * mg_value(internalWeight) / 100,
Options[egOpt] * eg_value(internalWeight) / 100 };
return w;
}
/// init() computes evaluation weights from the corresponding UCI parameters
/// and setup king tables.
// interpolate() interpolates between a middlegame and an endgame score,
// based on game phase. It also scales the return value by a ScaleFactor array.
void init() {
Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
Weights[Mobility] = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[Mobility]);
Weights[PawnStructure] = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
Weights[PassedPawns] = weight_option("Passed Pawns (Midgame)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
assert(-VALUE_INFINITE < mg_value(v) && mg_value(v) < VALUE_INFINITE);
assert(-VALUE_INFINITE < eg_value(v) && eg_value(v) < VALUE_INFINITE);
assert(PHASE_ENDGAME <= ph && ph <= PHASE_MIDGAME);
const int MaxSlope = 30;
const int Peak = 1280;
for (int t = 0, i = 1; i < 100; ++i)
{
t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
}
int eg = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
return Value((mg_value(v) * int(ph) + eg * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME);
}
} // namespace Eval
namespace {
template<bool Trace>
Value do_evaluate(const Position& pos) {
assert(!pos.checkers());
EvalInfo ei;
Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };
Thread* thisThread = pos.this_thread();
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables) and adding a
// Tempo bonus. Score is computed from the point of view of white.
score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
// Probe the material hash table
ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames);
score += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (ei.mi->specialized_eval_exists())
return ei.mi->evaluate(pos);
// Probe the pawn hash table
ei.pi = Pawns::probe(pos, thisThread->pawnsTable);
score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
// Initialize attack and king safety bitboards
init_eval_info<WHITE>(pos, ei);
init_eval_info<BLACK>(pos, ei);
ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING];
ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING];
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)),
~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) };
// Evaluate pieces and mobility
score += evaluate_pieces<KNIGHT, WHITE, Trace>(pos, ei, mobility, mobilityArea);
score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]);
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
score += evaluate_king<WHITE, Trace>(pos, ei)
- evaluate_king<BLACK, Trace>(pos, ei);
// Evaluate tactical threats, we need full attack information including king
score += evaluate_threats<WHITE, Trace>(pos, ei)
- evaluate_threats<BLACK, Trace>(pos, ei);
// Evaluate passed pawns, we need full attack information including king
score += evaluate_passed_pawns<WHITE, Trace>(pos, ei)
- evaluate_passed_pawns<BLACK, Trace>(pos, ei);
// If one side has only a king, score for potential unstoppable pawns
if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
score += evaluate_unstoppable_pawns(pos, WHITE, ei)
- evaluate_unstoppable_pawns(pos, BLACK, ei);
// Evaluate space for both sides, only in middlegame
if (ei.mi->space_weight())
{
int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
}
// Scale winning side if position is more drawish than it appears
ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
: ei.mi->scale_factor(pos, BLACK);
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
if ( ei.mi->game_phase() < PHASE_MIDGAME
&& pos.opposite_bishops()
&& (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
{
// Ignoring any pawns, do both sides only have a single bishop and no
// other pieces?
if ( pos.non_pawn_material(WHITE) == BishopValueMg
&& pos.non_pawn_material(BLACK) == BishopValueMg)
{
// Check for KBP vs KB with only a single pawn that is almost
// certainly a draw or at least two pawns.
bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
}
else
// Endgame with opposite-colored bishops, but also other pieces. Still
// a bit drawish, but not as drawish as with only the two bishops.
sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
}
Value v = interpolate(score, ei.mi->game_phase(), sf);
// In case of tracing add all single evaluation contributions for both white and black
if (Trace)
{
Tracing::add_term(Tracing::PST, pos.psq_score());
Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value());
Tracing::add_term(PAWN, ei.pi->pawns_value());
Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
, apply_weight(mobility[BLACK], Weights[Mobility]));
Score w = ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei);
Score b = ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei);
Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
Tracing::add_term(Tracing::TOTAL, score);
Tracing::ei = ei;
Tracing::sf = sf;
}
return pos.side_to_move() == WHITE ? v : -v;
}
// init_eval_info() initializes king bitboards for given color adding
// pawn attacks. To be done at the beginning of the evaluation.
@ -463,6 +301,7 @@ Value do_evaluate(const Position& pos) {
Square s;
Score score = SCORE_ZERO;
const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square* pl = pos.list<Pt>(Us);
@ -574,8 +413,6 @@ Value do_evaluate(const Position& pos) {
if (Trace)
Tracing::terms[Us][Pt] = score;
const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
return score - evaluate_pieces<NextPt, Them, Trace>(pos, ei, mobility, mobilityArea);
}
@ -899,33 +736,120 @@ Value do_evaluate(const Position& pos) {
}
// interpolate() interpolates between a middlegame and an endgame score,
// based on game phase. It also scales the return value by a ScaleFactor array.
// do_evaluate() is the evaluation entry point, called directly from evaluate()
Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
template<bool Trace>
Value do_evaluate(const Position& pos) {
assert(-VALUE_INFINITE < mg_value(v) && mg_value(v) < VALUE_INFINITE);
assert(-VALUE_INFINITE < eg_value(v) && eg_value(v) < VALUE_INFINITE);
assert(PHASE_ENDGAME <= ph && ph <= PHASE_MIDGAME);
assert(!pos.checkers());
int eg = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
return Value((mg_value(v) * int(ph) + eg * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME);
}
EvalInfo ei;
Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };
Thread* thisThread = pos.this_thread();
// apply_weight() weights score v by score w trying to prevent overflow
Score apply_weight(Score v, const Weight& w) {
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables) and adding a
// Tempo bonus. Score is computed from the point of view of white.
score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256);
}
// Probe the material hash table
ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames);
score += ei.mi->material_value();
// weight_option() computes the value of an evaluation weight, by combining
// two UCI-configurable weights (midgame and endgame) with an internal weight.
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (ei.mi->specialized_eval_exists())
return ei.mi->evaluate(pos);
Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
// Probe the pawn hash table
ei.pi = Pawns::probe(pos, thisThread->pawnsTable);
score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
Weight w = { Options[mgOpt] * mg_value(internalWeight) / 100,
Options[egOpt] * eg_value(internalWeight) / 100 };
return w;
// Initialize attack and king safety bitboards
init_eval_info<WHITE>(pos, ei);
init_eval_info<BLACK>(pos, ei);
ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING];
ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING];
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)),
~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) };
// Evaluate pieces and mobility
score += evaluate_pieces<KNIGHT, WHITE, Trace>(pos, ei, mobility, mobilityArea);
score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]);
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
score += evaluate_king<WHITE, Trace>(pos, ei)
- evaluate_king<BLACK, Trace>(pos, ei);
// Evaluate tactical threats, we need full attack information including king
score += evaluate_threats<WHITE, Trace>(pos, ei)
- evaluate_threats<BLACK, Trace>(pos, ei);
// Evaluate passed pawns, we need full attack information including king
score += evaluate_passed_pawns<WHITE, Trace>(pos, ei)
- evaluate_passed_pawns<BLACK, Trace>(pos, ei);
// If one side has only a king, score for potential unstoppable pawns
if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
score += evaluate_unstoppable_pawns(pos, WHITE, ei)
- evaluate_unstoppable_pawns(pos, BLACK, ei);
// Evaluate space for both sides, only in middlegame
if (ei.mi->space_weight())
{
int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
}
// Scale winning side if position is more drawish than it appears
ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
: ei.mi->scale_factor(pos, BLACK);
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
if ( ei.mi->game_phase() < PHASE_MIDGAME
&& pos.opposite_bishops()
&& (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
{
// Ignoring any pawns, do both sides only have a single bishop and no
// other pieces?
if ( pos.non_pawn_material(WHITE) == BishopValueMg
&& pos.non_pawn_material(BLACK) == BishopValueMg)
{
// Check for KBP vs KB with only a single pawn that is almost
// certainly a draw or at least two pawns.
bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
}
else
// Endgame with opposite-colored bishops, but also other pieces. Still
// a bit drawish, but not as drawish as with only the two bishops.
sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
}
Value v = interpolate(score, ei.mi->game_phase(), sf);
// In case of tracing add all single evaluation contributions for both white and black
if (Trace)
{
Tracing::add_term(Tracing::PST, pos.psq_score());
Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value());
Tracing::add_term(PAWN, ei.pi->pawns_value());
Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
, apply_weight(mobility[BLACK], Weights[Mobility]));
Score w = ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei);
Score b = ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei);
Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
Tracing::add_term(Tracing::TOTAL, score);
Tracing::ei = ei;
Tracing::sf = sf;
}
return pos.side_to_move() == WHITE ? v : -v;
}
@ -994,4 +918,52 @@ Value do_evaluate(const Position& pos) {
return ss.str();
}
}
} // namespace
namespace Eval {
/// evaluate() is the main evaluation function. It always computes two
/// values, an endgame score and a middlegame score, and interpolates
/// between them based on the remaining material.
Value evaluate(const Position& pos) {
return do_evaluate<false>(pos);
}
/// trace() is like evaluate(), but instead of returning a value, it returns
/// a string (suitable for outputting to stdout) that contains the detailed
/// descriptions and values of each evaluation term. It's mainly used for
/// debugging.
std::string trace(const Position& pos) {
return Tracing::do_trace(pos);
}
/// init() computes evaluation weights from the corresponding UCI parameters
/// and setup king tables.
void init() {
Weights[Mobility] = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[Mobility]);
Weights[PawnStructure] = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
Weights[PassedPawns] = weight_option("Passed Pawns (Midgame)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
const int MaxSlope = 30;
const int Peak = 1280;
for (int t = 0, i = 1; i < 100; ++i)
{
t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
}
}
} // namespace Eval