int Perft(POS *p, int ply, int depth) {
int move = 0;
int fl_mv_type;
MOVES m[1];
UNDO u[1];
int mv_cnt = 0;
InitMoves(p, m, 0, 0, ply);
while (move = NextMove(m, &fl_mv_type)) {
p->DoMove(move, u);
if (Illegal(p)) { p->UndoMove(move, u); continue; }
if (depth == 1) mv_cnt++;
else mv_cnt += Perft(p, ply + 1, depth - 1);
p->UndoMove(move, u);
}
return mv_cnt;
}
// Algorithme de recherche MinMax avec des coupes Alpha-Beta.
int Search(int depth, int ply, int wtm, int alpha, int beta, bool do_null)
{
register int Valeur, AlphaInitiale, check_ext = 0, extension = 0,
MoveCherche, danger = 0;
if ( ply >= MAXPLY-1 )
return beta;
iNodes++;
// Si on n'est pas en mode Analyse, Reste-t-il du temps?
if ( interrupted || (timeabort && !g_bModeAnalyse) ) {
return beta;
}
AlphaInitiale = alpha;
// Calculer le temps restant.
if ( (iNodes & 0xFF ) == 0xFF ) {
if ( TimeCheck() ) {
timeabort = true;
}
// Verifier si il y a quelque chose dans le tampon
// d'entree.
if ( inter() ) {
char buf[10];
int c = fgetc(stdin);
if (c == 10)
{
c = fgetc(stdin);
ungetc(c, stdin);
if (c == '.')
{
scanf("%s", &buf);
printf( "stat01: %d %d %d %d %d\n", (TempsCenti()-timestamp),
iNodes, iProfondeurIteration, cb.MoveList[1].nbmove - cb.MoveList[1].currmove-1,
cb.MoveList[1].nbmove );
journal.Log("received a dot\n");
}
else
{
interrupted = true;
}
}
else
{
ungetc(c, stdin);
interrupted = true;
}
}
}
// Verifier si ce n'est pas une nulle.
if (Repetition(wtm)) {
//if ( 0 < beta ) {
// pv[ply-1][ply-1] = cb.CurrentPath.moves[ply-1];
return 0;
// if ( wtm ) {
// return DRAWSCORE;
// }
// else {
// return -DRAWSCORE;
// }
//}
}
// Regarder dans la table de transposition pour voir si cette position
// n'a pas deja ete calculer.
#ifdef TRANSPOSITION
switch( TableTrans->Lookup( cb, ply, depth,
wtm, alpha, beta, danger ) ) {
case SCORE_EXACTE:
return alpha;
case BORNE_SUPERIEUR:
return alpha;
case BORNE_INFERIEUR:
return beta;
case EVITER_NULL:
do_null = false;
}
#endif
#ifdef NULL_MOVE
// En premier, on essai le NULL MOVE.
if ( do_null ) {
int nbPiece = wtm?cb.TotalMaterielBlanc:cb.TotalMaterielNoir;
if ( !cb.inCheck[ply] && nbPiece > 5 && depth > 3 && alpha == beta-1) {
int EnPassantB = cb.EnPassantB[ply+1];
int EnPassantN = cb.EnPassantN[ply+1];
cb.EnPassantB[ply+1] = -1;
cb.EnPassantN[ply+1] = -1;
Valeur = -Search(depth-3, ply+1, !wtm, -beta, -beta+1, false);
cb.EnPassantB[ply+1] = EnPassantB;
cb.EnPassantN[ply+1] = EnPassantN;
if ( Valeur >= beta ) {
#ifdef TRANSPOSITION
TableTrans->StoreRefutation( cb, ply, depth,
wtm, Valeur, alpha, beta, danger );
#endif
return Valeur;
}
if ( Valeur <= -MATE+50 )
danger = 1;
}
}
#endif
// Internal Iterative Deepening.
/* if ( depth > 2 && ((!(ply&1) && alpha==root_alpha && beta==root_beta) ||
((ply&1) && alpha==-root_beta && beta==-root_alpha)) &&
cb.HashMove[ply].From == 0 && cb.HashMove[ply].To == 0 ) {
Valeur = ABSearch( cb, depth-2, ply, wtm, alpha, beta, true );
if ( Valeur <= alpha ) {
Valeur = ABSearch( cb, depth-2, ply, wtm, -MATE, beta, true );
}
else {
if ( Valeur < beta ) {
cb.HashMove[ply] = pv[ply-1][ply];
}
else cb.HashMove[ply] = cb.CurrentPath.moves[ply];
}
}*/
#ifdef TRANSPOSITION
Phase[ply] = HASH_MOVE;
#else
// if ( ((!(ply&1) && alpha==root_alpha && beta==root_beta) ||
// ( (ply&1) && alpha==-root_beta && beta==-root_alpha)) )
Phase[ply] = PV_MOVE;
// else
// Phase[ply] = GENERATE_CAPTURE_MOVES;
#endif
// Maintenant, evaluer chaque coup.
MoveCherche = 0;
while( Phase[ply] != NO_MORE_MOVES && !interrupted ) {
if ( NextMove( cb, ply, wtm ) ) {
// Si
// On execute le coup.
MakeMove(ply, cb.MoveList[ply].CurrentMove(), wtm);
// Mettre le coup dans le chemin actuel.
cb.CurrentPath.moves[ply] = cb.MoveList[ply].moves[cb.MoveList[ply].currmove];
if (!Check(wtm)) {
MoveCherche++;
// Si le coup met en echec etendre la recherche d'une profondeur
// pour qu'il puisse en sortir.
if (Check(!wtm) ) {
cb.inCheck[ply+1] = true;
extension = 1;
cb.RaisonExtension[ply] = EXTENSION_ECHEC;
}
else {
extension = 0;
cb.inCheck[ply+1] = false;
cb.RaisonExtension[ply] = PAS_EXTENSION;
}
// Si le coup est une recapture
// etendre la recherche d'une profondeur.
if ( cb.CurrentPath.moves[ply].Capture &&
abs(ValeurPiece[cb.CurrentPath.moves[ply-1].Capture] - ValeurPiece[cb.CurrentPath.moves[ply].Capture]) <= 20 &&
(cb.CurrentPath.moves[ply-1].To ==
cb.CurrentPath.moves[ply].To) &&
cb.RaisonExtension[ply-1] != EXTENSION_RECAPTURE) {
extension = 1;
cb.RaisonExtension[ply] = EXTENSION_RECAPTURE;
}
// Si on est sur le point de promouvoir un pion, étendre la recherche
// pour voir si c'est une menace.
if ( extension == 0 && cb.CurrentPath.moves[ply].Piece == 1 &&
PromoteExtension[ cb.CurrentPath.moves[ply].To ] ) {
extension = 1;
cb.RaisonExtension[ply] = EXTENSION_PROMOTION;
}
// Si on pousse un pion passe, pousser la recherche plus
// loin pour voir si c'est un danger.
if ( cb.CurrentPath.moves[ply].Piece == pion )
if ( wtm ) {
if ( cb.CurrentPath.moves[ply].To <= H5 )
if ( cb.PionPasseB[cb.CurrentPath.moves[ply].To&7] ) {
extension = 1;
cb.RaisonExtension[ply] = EXTENSION_PIONPASSE;
}
}
else {
if ( cb.CurrentPath.moves[ply].To >= A4 )
if ( cb.PionPasseN[cb.CurrentPath.moves[ply].To&7] ) {
extension = 1;
cb.RaisonExtension[ply] = EXTENSION_PIONPASSE;
}
}
// Razoring trick. Idee prise dans Crafty.
if ( depth == 2 && !cb.inCheck[ply] && extension == 0 ) {
int valeur;
if ( wtm )
valeur = Eval(ply, wtm, alpha, beta);
else
valeur = -Eval(ply, wtm, alpha, beta);
if ( valeur+50 < alpha )
extension = -1;
}
// On l'explore.
// Si c'est la variation principale, Fenetre normale, sinon,
// fenetre est n et n+1.
int inpv = 1;
if (ply&1) {
if ( alpha != root_alpha || beta != root_beta ) inpv = 0;
}
else {
if ( alpha != -root_beta || beta != -root_alpha ) inpv = 0;
}
if ( inpv ) {
Valeur = -ABSearch(depth-1+extension+danger, ply+1, !wtm, -beta, -alpha, true);
}
else {
Valeur = -ABSearch(depth-1+extension+danger, ply+1, !wtm, -alpha-1, -alpha, true);
if ( Valeur > alpha && Valeur < beta ) {
pvsresearch++;
Valeur = -ABSearch(depth-1+extension+danger, ply+1, !wtm, -beta, -alpha, true);
}
}
}
else {
Valeur = -INFINI;
}
cb.MoveList[ply].CurrentMove().Score = Valeur;
// On defait le coup.
UnmakeMove(ply, cb.MoveList[ply].CurrentMove(), wtm);
if (interrupted)
return Valeur;
#ifdef DEBUG
Consistence( cb, cb.MoveList[ply].CurrentMove() );
#endif
// Est-il meilleur que notre valeur actuelle?
if ( Valeur > alpha ) {
if ( Valeur >= beta ) {
#ifdef TRANSPOSITION
TableTrans->StoreRefutation( cb, ply, depth,
wtm, Valeur, alpha, beta, check_ext );
#endif
g_iRefutation++;
// Verifier si on peu l'utiliser comme killer move.
if ( Phase[ply] == NON_CAPTURE_MOVES ) {
cb.AddKiller( &cb.CurrentPath.moves[ply-1], ply-1 );
}
else {
if ( Phase[ply] == KILLER_MOVE_2 )
cb.Killers[ply-1][0].Score++;
else if ( Phase[ply] == GENERATE_NON_CAPTURE_MOVES )
cb.Killers[ply-1][1].Score++;
}
return Valeur;
}
pv[ply][ply] = cb.CurrentPath.moves[ply];
pv_length[ply] = pv_length[ply+1];
memcpy(&pv[ply][ply+1], &pv[ply+1][ply+1], sizeof(TMove)*(pv_length[ply]-ply));
alpha = Valeur;
}
} // if
}
// Verifier si il y a mat ou pat.
if ( MoveCherche == 0 ) {
if (!Check(wtm)) {
pv[ply][ply] = cb.CurrentPath.moves[ply];
return 0;
// if ( wtm ) {
// return DRAWSCORE;
// }
// else {
// return -DRAWSCORE;
// }
}
else {
if ( ply < iMateInPly )
iMateInPly = ply;
alpha = -MATE+iMateInPly;
}
}
#ifdef TRANSPOSITION
TableTrans->StoreBest( cb, ply, depth, wtm,
alpha, AlphaInitiale, danger );
#endif
return alpha;
}
static int negascout(struct SearchData *sd,
int alpha,
int beta,
const int depth,
int node_type
#if MP
,int exclusiveP
#endif /* MP */
) {
struct Position *p = sd->position;
struct SearchStatus *st;
int best = -INF;
int bestm = M_NONE;
int tmp;
int talpha;
int incheck;
int lmove;
int move;
int extend = 0;
int threat = FALSE;
int reduce_extensions;
int next_type;
int was_futile = FALSE;
#if FUTILITY
int is_futile;
int optimistic = 0;
#endif
#if MP
int deferred_cnt = 0;
int deferred_list[MAX_DEFERRED];
int deferred_depth[MAX_DEFERRED];
#endif
EnterNode(sd);
Nodes++;
/* check for search termination */
if (sd->master && TerminateSearch(sd)) {
AbortSearch = TRUE;
goto EXIT;
}
/* max search depth reached */
if (sd->ply >= MaxDepth) goto EXIT;
/*
* Check for insufficent material or theoretical draw.
*/
if ( /* InsufMat(p) || CheckDraw(p) || */ Repeated(p, FALSE)) {
best = 0;
goto EXIT;
}
/*
* check extension
*/
incheck = InCheck(p, p->turn);
if (incheck && p->material[p->turn] > 0) {
extend += CheckExtend(p);
ChkExt++;
}
/*
* Check the hashtable
*/
st = sd->current;
HTry++;
#if MP
switch (ProbeHT(p->hkey, &tmp, depth, &(st->st_hashmove), &threat, sd->ply,
exclusiveP, sd->localHashTable))
#else
switch (ProbeHT(p->hkey, &tmp, depth, &(st->st_hashmove), &threat, sd->ply))
#endif /* MP */
{
case ExactScore:
HHit++;
best = tmp;
goto EXIT;
case UpperBound:
if (tmp <= alpha) {
HHit++;
best = tmp;
goto EXIT;
}
break;
case LowerBound:
if (tmp >= beta) {
HHit++;
best = tmp;
goto EXIT;
}
break;
case Useless:
threat = !incheck && MateThreat(p, OPP(p->turn));
break;
#if MP
case OnEvaluation:
best = -ON_EVALUATION;
goto EXIT;
#endif
}
/*
* Probe EGTB
*/
if (depth > EGTBDepth && ProbeEGTB(p, &tmp, sd->ply)) {
best = tmp;
goto EXIT;
}
/*
* Probe recognizers
*/
switch (ProbeRecognizer(p, &tmp)) {
case ExactScore:
best = tmp;
goto EXIT;
case LowerBound:
if (tmp >= beta) {
best = tmp;
goto EXIT;
}
break;
case UpperBound:
if (tmp <= alpha) {
best = tmp;
goto EXIT;
}
break;
}
#if NULLMOVE
/*
* Null move search.
* See Christian Donninger, "Null Move and Deep Search"
* ICCA Journal Volume 16, No. 3, pp. 137-143
*/
if (!incheck && node_type == CutNode && !threat) {
int next_depth;
int nms;
next_depth = depth - ReduceNullMove;
if (next_depth > 0) {
next_depth = depth - ReduceNullMoveDeep;
}
DoNull(p);
if (next_depth < 0) {
nms = -quies(sd, -beta, -beta+1, 0);
} else {
#if MP
nms = -negascout(sd, -beta, -beta+1, next_depth, AllNode, 0);
#else
nms = -negascout(sd, -beta, -beta+1, next_depth, AllNode);
#endif
}
UndoNull(p);
if (AbortSearch) goto EXIT;
if (nms >= beta) {
if (p->nonPawn[p->turn] >= Value[Queen]) {
best = nms;
goto EXIT;
} else {
if (next_depth < 0) {
nms = quies(sd, beta-1, beta, 0);
} else {
#if MP
nms = negascout(sd, beta-1, beta, next_depth, CutNodeNoNull,
0);
#else
nms = negascout(sd, beta-1, beta, next_depth,
CutNodeNoNull);
#endif
}
if (nms >= beta) {
best = nms;
goto EXIT;
} else {
extend += ExtendZugzwang;
ZZExt++;
}
}
} else if (nms <= -CMLIMIT) {
threat = TRUE;
}
}
#endif /* NULLMOVE */
lmove = (p->actLog-1)->gl_Move;
reduce_extensions = (sd->ply > 2*sd->depth);
talpha = alpha;
switch (node_type) {
case AllNode:
next_type = CutNode;
break;
case CutNode:
case CutNodeNoNull:
next_type = AllNode;
break;
default:
next_type = PVNode;
break;
}
#if FUTILITY
is_futile = !incheck && !threat && alpha < CMLIMIT && alpha > -CMLIMIT;
if (is_futile) {
if (p->turn == White) {
optimistic = MaterialBalance(p) + MaxPos;
} else {
optimistic = -MaterialBalance(p) + MaxPos;
}
}
#endif /* FUTILITY */
/*
* Internal iterative deepening. If we do not have a move, we try
* a shallow search to find a good candidate.
*/
if (depth > 2*OnePly && ((alpha + 1) != beta) && !LegalMove(p, st->st_hashmove)) {
int useless;
#if MP
useless = negascout(sd, alpha, beta, depth-2*OnePly, PVNode, 0);
#else
useless = negascout(sd, alpha, beta, depth-2*OnePly, PVNode);
#endif
st->st_hashmove = sd->pv_save[sd->ply+1];
}
/*
* Search all legal moves
*/
while ((move = incheck ? NextEvasion(sd) : NextMove(sd)) != M_NONE) {
int next_depth = extend;
if (move & M_CANY && !MayCastle(p, move)) continue;
/*
* recapture extension
*/
if ((move & M_CAPTURE) && (lmove & M_CAPTURE) &&
M_TO(move) == M_TO(lmove) &&
IsRecapture(p->piece[M_TO(move)], (p->actLog-1)->gl_Piece)) {
RCExt += 1;
next_depth += ExtendRecapture[TYPE(p->piece[M_TO(move)])];
}
/*
* passed pawn push extension
*/
if (TYPE(p->piece[M_FROM(move)]) == Pawn &&
p->nonPawn[OPP(p->turn)] <= Value[Queen]) {
int to = M_TO(move);
if (((p->turn == White && to >= a7)
|| (p->turn == Black && to <= h2))
&& IsPassed(p, to, p->turn) && SwapOff(p, move) >= 0) {
next_depth += ExtendPassedPawn;
PPExt += 1;
}
}
/*
* limit extensions to sensible range.
*/
if (reduce_extensions) next_depth /= 2;
next_depth += depth - OnePly;
#if FUTILITY
/*
* Futility cutoffs
*/
if (is_futile) {
if (next_depth < 0 && !IsCheckingMove(p, move)) {
tmp = optimistic + ScoreMove(p, move);
if (tmp <= alpha) {
if (tmp > best) {
best = tmp;
bestm = move;
was_futile = TRUE;
}
continue;
}
}
#if EXTENDED_FUTILITY
/*
* Extended futility cutoffs and limited razoring.
* See Ernst A. Heinz, "Extended Futility Pruning"
* ICCA Journal Volume 21, No. 2, pp 75-83
*/
else if (next_depth >= 0 && next_depth < OnePly
&& !IsCheckingMove(p, move)) {
tmp = optimistic + ScoreMove(p, move) + (3*Value[Pawn]);
if (tmp <= alpha) {
if (tmp > best) {
best = tmp;
bestm = move;
was_futile = TRUE;
}
continue;
}
}
#if RAZORING
else if (next_depth >= OnePly && next_depth < 2*OnePly
&& !IsCheckingMove(p, move)) {
tmp = optimistic + ScoreMove(p, move) + (6*Value[Pawn]);
if (tmp <= alpha) {
next_depth -= OnePly;
}
}
#endif /* RAZORING */
#endif /* EXTENDED_FUTILITY */
}
#endif /* FUTILITY */
DoMove(p, move);
if (InCheck(p, OPP(p->turn))) {
UndoMove(p, move);
} else {
/*
* Check extension
*/
if (p->material[p->turn] > 0 && InCheck(p, p->turn)) {
next_depth += (reduce_extensions) ?
ExtendInCheck>>1 : ExtendInCheck;
}
/*
* Recursively search this position. If depth is exhausted, use
* quies, otherwise use negascout.
*/
if (next_depth < 0) {
tmp = -quies(sd, -beta, -talpha, 0);
} else if (bestm != M_NONE && !was_futile) {
#if MP
tmp = -negascout(sd, -talpha-1, -talpha, next_depth, next_type,
bestm != M_NONE);
if (tmp != ON_EVALUATION && tmp > talpha && tmp < beta) {
tmp = -negascout(sd, -beta, -tmp, next_depth,
node_type == PVNode ? PVNode : AllNode,
bestm != M_NONE);
}
#else
tmp = -negascout(sd, -talpha-1, -talpha, next_depth, next_type);
if (tmp > talpha && tmp < beta) {
tmp = -negascout(sd, -beta, -tmp, next_depth,
node_type == PVNode ? PVNode : AllNode);
}
#endif /* MP */
} else {
#if MP
tmp = -negascout(sd, -beta, -talpha, next_depth, next_type,
bestm != M_NONE);
#else
tmp = -negascout(sd, -beta, -talpha, next_depth, next_type);
#endif /* MP */
}
UndoMove(p, move);
if (AbortSearch) goto EXIT;
#if MP
if (tmp == ON_EVALUATION) {
/*
* This child is ON_EVALUATION. Remember move and
* depth.
*/
deferred_list[deferred_cnt] = move;
deferred_depth[deferred_cnt] = next_depth;
deferred_cnt++;
} else {
#endif /* MP */
/*
* beta cutoff, enter move in Killer/Countermove table
*/
if (tmp >= beta) {
if (!(move & M_TACTICAL)) {
PutKiller(sd, move);
sd->counterTab[p->turn][lmove & 4095] = move;
}
StoreResult(sd, tmp, alpha, beta, move, depth, threat);
best = tmp;
goto EXIT;
}
/*
* Improvement on best move to date
*/
if (tmp > best) {
best = tmp;
bestm = move;
was_futile = FALSE;
if (best > talpha) {
talpha = best;
}
}
next_type = CutNode;
#if MP
}
#endif /* MP */
}
}
/*
********************************************************************************
* *
* Search() is the recursive routine used to implement the alpha/beta *
* negamax search (similar to minimax but simpler to code.) Search() is *
* called whenever there is "depth" remaining so that all moves are subject *
* to searching, or when the side to move is in check, to make sure that this *
* side isn't mated. Search() recursively calls itself until depth is ex- *
* hausted, at which time it calls Quiesce() instead. *
* *
********************************************************************************
*/
int Search(int alpha, int beta, int wtm, int depth, int ply, int do_null)
{
register int first_move=1;
register BITBOARD save_hash_key;
register int initial_alpha, value;
register int extensions;
/*
----------------------------------------------------------
| |
| check to see if we have searched enough nodes that it |
| is time to peek at how much time has been used, or if |
| is time to check for operator keyboard input. this is |
| usually enough nodes to force a time/input check about |
| once per second, except when the target time per move |
| is very small, in which case we try to check the time |
| at least 10 times during the search. |
| |
----------------------------------------------------------
*/
if (ply >= MAXPLY-2) return(beta);
nodes_searched++;
if (--next_time_check <= 0) {
next_time_check=nodes_between_time_checks;
if (CheckInput()) Interrupt(ply);
time_abort+=TimeCheck(0);
if (time_abort) {
abort_search=1;
return(0);
}
}
/*
----------------------------------------------------------
| |
| check for draw by repetition. |
| |
----------------------------------------------------------
*/
if (RepetitionCheck(ply,wtm)) {
value=(wtm==root_wtm) ? DrawScore() : -DrawScore();
if (value < beta) SavePV(ply,value,0);
#if !defined(FAST)
if(ply <= trace_level) printf("draw by repetition detected, ply=%d.\n",ply);
#endif
return(value);
}
/*
----------------------------------------------------------
| |
| now call LookUp() to see if this position has been |
| searched before. if so, we may get a real score, |
| produce a cutoff, or get nothing more than a good move |
| to try first. there are four cases to handle: |
| |
| 1. LookUp() returned "EXACT_SCORE" if this score is |
| greater than beta, return beta. otherwise, return the |
| score. In either case, no further searching is needed |
| from this position. note that lookup verified that |
| the table position has sufficient "draft" to meet the |
| requirements of the current search depth remaining. |
| |
| 2. LookUp() returned "LOWER_BOUND" which means that |
| when this position was searched previously, every move |
| was "refuted" by one of its descendents. as a result, |
| when the search was completed, we returned alpha at |
| that point. we simply return alpha here as well. |
| |
| 3. LookUp() returned "UPPER_BOUND" which means that |
| when we encountered this position before, we searched |
| one branch (probably) which promptly refuted the move |
| at the previous ply. |
| |
| 4. LookUp() returned "AVOID_NULL_MOVE" which means |
| the hashed score/bound was no good, but it indicated |
| that trying a null-move in this position will be a |
| waste of time. |
| |
----------------------------------------------------------
*/
switch (LookUp(ply,depth,wtm,&alpha,beta)) {
case EXACT_SCORE:
if(alpha >= beta) return(beta);
else {
SavePV(ply,alpha,1);
return(alpha);
}
case LOWER_BOUND:
return(alpha);
case UPPER_BOUND:
return(beta);
case AVOID_NULL_MOVE:
do_null=0;
}
/*
----------------------------------------------------------
| |
| now it's time to try a probe into the endgame table- |
| base files. this is done if (a) the previous move was |
| a capture or promotion, unless we are at very shallow |
| plies (<4) in the search; (b) there are less than 5 |
| pieces left (currently all interesting 4 piece endings |
| are available.) |
| |
----------------------------------------------------------
*/
#if defined(TABLEBASES)
if (TotalPieces < 5) do {
register int wpawn, bpawn;
int tb_value;
if (TotalWhitePawns && TotalBlackPawns) {
wpawn=FirstOne(WhitePawns);
bpawn=FirstOne(BlackPawns);
if (FileDistance(wpawn,bpawn) == 1) {
if(((Rank(wpawn)==1) && (Rank(bpawn)>2)) ||
((Rank(bpawn)==6) && (Rank(wpawn)<5)) ||
EnPassant(ply)) break;
}
}
tb_probes++;
if (EGTBScore(ply, wtm, &tb_value)) {
tb_probes_successful++;
alpha=tb_value;
if (abs(alpha) > MATE-100) alpha+=(alpha > 0) ? -(ply-1) : +(ply-1);
else if (alpha == 0) alpha=(wtm==root_wtm) ? DrawScore() : -DrawScore();
if(alpha >= beta) return(beta);
else {
SavePV(ply,alpha,2);
return(alpha);
}
}
} while(0);
# endif
/*
----------------------------------------------------------
| |
| initialize. |
| |
----------------------------------------------------------
*/
in_check[ply+1]=0;
extended_reason[ply+1]=no_extension;
initial_alpha=alpha;
last[ply]=last[ply-1];
killer_count1[ply+1]=0;
killer_count2[ply+1]=0;
/*
----------------------------------------------------------
| |
| first, we try a null move to see if we can get a quick |
| cutoff with only a little work. this operates as |
| follows. instead of making a legal move, the side on |
| move 'passes' and does nothing. the resulting position |
| is searched to a shallower depth than normal (usually |
| one ply less but settable by the operator) this should |
| result in a cutoff or at least should set the lower |
| bound better since anything should be better than not |
| doing anything. |
| |
| this is skipped for any of the following reasons: |
| |
| 1. the side on move is in check. the null move |
| results in an illegal position. |
| 2. no more than one null move can appear in succession |
| or else the search will degenerate into nothing. |
| 3. the side on move has little material left making |
| zugzwang positions more likely. |
| |
----------------------------------------------------------
*/
# if defined(NULL_MOVE_DEPTH)
if (do_null && !in_check[ply] &&
((wtm) ? TotalWhitePieces : TotalBlackPieces)>2) {
current_move[ply]=0;
current_phase[ply]=NULL_MOVE;
#if !defined(FAST)
if (ply <= trace_level)
SearchTrace(ply,depth,wtm,alpha,beta,"Search",0);
#endif
position[ply+1]=position[ply];
Rule50Moves(ply+1)++;
save_hash_key=HashKey;
if (EnPassant(ply)) {
HashEP(EnPassant(ply+1),HashKey);
EnPassant(ply+1)=0;
}
if ((depth-NULL_MOVE_DEPTH-INCREMENT_PLY) >= INCREMENT_PLY)
value=-Search(-beta,-alpha,ChangeSide(wtm),depth-NULL_MOVE_DEPTH-INCREMENT_PLY,ply+1,NO_NULL);
else
value=-Quiesce(-beta,-alpha,ChangeSide(wtm),ply+1);
HashKey=save_hash_key;
if (abort_search) return(0);
if (value >= beta) {
StoreRefutation(ply,depth,wtm,beta);
return(beta);
}
}
# endif
/*
----------------------------------------------------------
| |
| if there is no best move from the hash table, and this |
| is a PV node, then we need a good move to search |
| first. while killers and history moves are good, they |
| are not "good enough". the simplest action is to try |
| a shallow search (depth-2) to get a move. note that |
| when we call Search() with depth-2, it, too, will |
| not have a hash move, and will therefore recursively |
| continue this process, hence the name "internal |
| iterative deepening." |
| |
----------------------------------------------------------
*/
next_status[ply].phase=FIRST_PHASE;
if (hash_move[ply]==0 && (depth > 2*INCREMENT_PLY) &&
(((ply & 1) && alpha == root_alpha && beta == root_beta) ||
(!(ply & 1) && alpha == -root_beta && beta == -root_alpha))) {
current_move[ply]=0;
value=Search(alpha,beta,wtm,depth-2*INCREMENT_PLY,ply,DO_NULL);
if (abort_search) return(0);
if (value <= alpha) {
value=Search(-MATE,beta,wtm,depth-2*INCREMENT_PLY,ply,DO_NULL);
if (abort_search) return(0);
}
else if (value < beta) {
if ((int) pv[ply-1].path_length >= ply) hash_move[ply]=pv[ply-1].path[ply];
}
else hash_move[ply]=current_move[ply];
last[ply]=last[ply-1];
next_status[ply].phase=FIRST_PHASE;
}
/*
----------------------------------------------------------
| |
| now iterate through the move list and search the |
| resulting positions. note that Search() culls any |
| move that is not legal by using Check(). the special |
| case is that we must find one legal move to search to |
| confirm that it's not a mate or draw. |
| |
----------------------------------------------------------
*/
while ((current_phase[ply]=(in_check[ply]) ? NextEvasion(ply,wtm) :
NextMove(depth,ply,wtm))) {
extended_reason[ply]&=check_extension;
#if !defined(FAST)
if (ply <= trace_level) SearchTrace(ply,depth,wtm,alpha,beta,"Search",current_phase[ply]);
#endif
/*
----------------------------------------------------------
| |
| if two successive moves are capture / re-capture so |
| that the material score is restored, extend the search |
| by one ply on the re-capture since it is pretty much |
| forced and easy to analyze. |
| |
----------------------------------------------------------
*/
extensions=-INCREMENT_PLY;
if (Captured(current_move[ply]) && Captured(current_move[ply-1]) &&
To(current_move[ply-1]) == To(current_move[ply]) &&
(p_values[Captured(current_move[ply-1])+7] ==
p_values[Captured(current_move[ply])+7] ||
Promote(current_move[ply-1])) &&
!(extended_reason[ply-1]&recapture_extension)) {
extended_reason[ply]|=recapture_extension;
recapture_extensions_done++;
extensions+=RECAPTURE;
}
/*
----------------------------------------------------------
| |
| if we push a passed pawn, we need to look deeper to |
| see if it is a legitimate threat. |
| |
----------------------------------------------------------
*/
if (Piece(current_move[ply])==pawn && !FutileAhead(wtm) &&
((wtm && To(current_move[ply])>H5 && TotalBlackPieces<16 &&
!And(mask_pawn_passed_w[To(current_move[ply])],BlackPawns)) ||
(!wtm && To(current_move[ply])<A4 && TotalWhitePieces<16 &&
!And(mask_pawn_passed_b[To(current_move[ply])],WhitePawns)) ||
push_extensions[To(current_move[ply])]) &&
Swap(From(current_move[ply]),To(current_move[ply]),wtm) >= 0) {
extended_reason[ply]|=passed_pawn_extension;
passed_pawn_extensions_done++;
extensions+=PASSED_PAWN_PUSH;
}
/*
----------------------------------------------------------
| |
| now make the move and search the resulting position. |
| if we are in check, the current move must be legal |
| since NextEvasion ensures this, otherwise we have to |
| make sure the side-on-move is not in check after the |
| move to weed out illegal moves and save time. |
| |
----------------------------------------------------------
*/
MakeMove(ply,current_move[ply],wtm);
if (in_check[ply] || !Check(wtm)) {
/*
----------------------------------------------------------
| |
| if the move to be made checks the opponent, then we |
| need to remember that he's in check and also extend |
| the depth by one ply for him to get out. |
| |
----------------------------------------------------------
*/
if (Check(ChangeSide(wtm))) {
in_check[ply+1]=1;
extended_reason[ply+1]=check_extension;
check_extensions_done++;
extensions+=IN_CHECK;
}
else {
in_check[ply+1]=0;
extended_reason[ply+1]=no_extension;
}
/*
----------------------------------------------------------
| |
| now we toss in the "razoring" trick, which simply says |
| if we are doing fairly badly, we can reduce the depth |
| an additional ply, if there was nothing at the current |
| ply that caused an extension. |
| |
----------------------------------------------------------
*/
if (depth < 3*INCREMENT_PLY && !in_check[ply] &&
extensions == -INCREMENT_PLY) {
register int val=(wtm) ? Material : -Material;
if (val+1500 < alpha) extensions-=INCREMENT_PLY;
}
/*
----------------------------------------------------------
| |
| if there's only one legal move, extend the search one |
| additional ply since this node is very easy to search. |
| |
----------------------------------------------------------
*/
if (first_move) {
if (last[ply]-last[ply-1] == 1) {
extended_reason[ply]|=one_reply_extension;
one_reply_extensions_done++;
extensions+=ONE_REPLY_TO_CHECK;
}
if (depth+MaxExtensions(extensions) >= INCREMENT_PLY)
value=-Search(-beta,-alpha,ChangeSide(wtm),depth+MaxExtensions(extensions),ply+1,DO_NULL);
else {
value=-Quiesce(-beta,-alpha,ChangeSide(wtm),ply+1);
}
if (abort_search) {
UnMakeMove(ply,current_move[ply],wtm);
return(0);
}
first_move=0;
}
else {
if (depth+MaxExtensions(extensions) >= INCREMENT_PLY)
value=-Search(-alpha-1,-alpha,ChangeSide(wtm),depth+MaxExtensions(extensions),ply+1,DO_NULL);
else {
value=-Quiesce(-alpha-1,-alpha,ChangeSide(wtm),ply+1);
}
if (abort_search) {
UnMakeMove(ply,current_move[ply],wtm);
return(0);
}
if (value>alpha && value<beta) {
if (depth+MaxExtensions(extensions) >= INCREMENT_PLY)
value=-Search(-beta,-alpha,ChangeSide(wtm),depth+MaxExtensions(extensions),ply+1,DO_NULL);
else
value=-Quiesce(-beta,-alpha,ChangeSide(wtm),ply+1);
if (abort_search) {
UnMakeMove(ply,current_move[ply],wtm);
return(0);
}
}
}
if (value > alpha) {
if(value >= beta) {
HistoryRefutation(ply,depth,wtm);
UnMakeMove(ply,current_move[ply],wtm);
StoreRefutation(ply,depth,wtm,beta);
return(beta);
}
alpha=value;
}
}
UnMakeMove(ply,current_move[ply],wtm);
}
/*
----------------------------------------------------------
| |
| all moves have been searched. if none were legal, |
| return either MATE or DRAW depending on whether the |
| side to move is in check or not. |
| |
----------------------------------------------------------
*/
if (first_move == 1) {
value=(Check(wtm)) ? -(MATE-ply) :
((wtm==root_wtm) ? DrawScore() : -DrawScore());
if(value > beta) value=beta;
else if (value < alpha) value=alpha;
if (value >=alpha && value <beta) {
SavePV(ply,value,0);
#if !defined(FAST)
if (ply <= trace_level) printf("Search() no moves! ply=%d\n",ply);
#endif
}
return(value);
}
else {
if (alpha != initial_alpha) {
memcpy(&pv[ply-1].path[ply],&pv[ply].path[ply],(pv[ply].path_length-ply+1)*4);
memcpy(&pv[ply-1].path_hashed,&pv[ply].path_hashed,3);
pv[ply-1].path[ply-1]=current_move[ply-1];
HistoryBest(ply,depth,wtm);
}
StoreBest(ply,depth,wtm,alpha,initial_alpha);
/*
----------------------------------------------------------
| |
| if the 50-move rule is drawing close, then adjust the |
| score to reflect the impending draw. |
| |
----------------------------------------------------------
*/
if (Rule50Moves(ply) > 99) {
value=(wtm==root_wtm) ? DrawScore() : -DrawScore();
if (value < beta) SavePV(ply,value,0);
#if !defined(FAST)
if(ply <= trace_level) printf("draw by 50-move rule detected, ply=%d.\n",ply);
#endif
return(value);
}
return(alpha);
}
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc1;
HDC hdc2;
int iSpeed = 500;
static int ** field_array;
RECT rcClientRect;
rcClientRect.top = 20;
rcClientRect.left = 200;
rcClientRect.bottom = rcClientRect.top + 25 * Rows;
rcClientRect.right = rcClientRect.left + 25 * Columns;
switch (message)
{
case WM_CREATE:
{
field_array = new int*[Rows];
for (int i = 0; i < Rows; i++)
{
field_array[i] = new int[Columns];
for (int j = 0; j < Columns; j++)
{
field_array[i][j] = 0;
}
}
field_array[0][0] = 1;
SetTimer(hWnd, ID_TIMER, iSpeed, NULL);
}
break;
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_TIMER:
NextMove(field_array);
InvalidateRect(hWnd, &rcClientRect, true);
break;
case WM_PAINT:
//hdc2 = GetDC(hWnd);
hdc1 = BeginPaint(hWnd, &ps);
DrawSquare(hdc1, rcClientRect, field_array);
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
// the window callback function
// which we passed a pointer to on the CreateMasterX method, this callback function contains a variable called
// msg that we switch and have different case 's for different messages windows sends are program
// like the WM_DESTROY message, this is were we post the quit message to break the while loop
// that we initilized in the InitLoop method.
LRESULT APIENTRY WndProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
switch(msg)
{
case WM_DESTROY:// called when the window is destroyed
PostQuitMessage(0);// breaks the while loop
break;
case WM_ACTIVATEAPP:
mxhwnd.activeapp = wParam;// sets the app as active
break;
case WM_KEYDOWN:// is sent when a key is pressed
{
switch(wParam) // contains the key that was pressed
{
case VK_ESCAPE:// when the escape key is pressed
{
mxhwnd.Kill();// break the while loop
}
break;
}
switch(mxhwnd.GetScreen())
{
case ID_GAME:
{
switch(wParam)
{
case VK_RETURN:
{
mxhwnd.SetScreen(ID_ABOUT);
}
break;
case VK_SPACE:
{
if(GameOver == true)// if the Game is Over then when they press space
{ // we wanna Clear the Board, Initilize the Players
ClearBoard(); // and set GameOver to false
InitPlayers();
GameOver = false;
}
}
break;
}
}
break;
case ID_ABOUT:
{
switch(wParam)
{
case VK_SPACE:
case VK_RETURN:
{
mxhwnd.SetScreen(ID_GAME);
}
break;
}
}
break;
}
}
break;
case WM_LBUTTONDOWN:// the WM_LBUTTONDOWN, when the left mouse button is clicked
{
int x = LOWORD(lParam), y = HIWORD(lParam);
if(GameOver == false)
{
// a if statement to check and see if they clicked within a rectangle
// if they did then set the Board[0][0] to the Player thats turn it is
if(x > 50 && x < 160 && y > 130 && y < 200)
{
// switch of the Player thats turn it is
switch(Player)
{
case 1:
{
if(Board[0][0] == EMPTY)
{
Board[0][0] = Player1; // set Board[0][0] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[0][0] == EMPTY)
{
Board[0][0] = Player2;// set Board[0][0] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to check and see if they clicked within a rectangle
// if they did then set Board[0][1] to Player thats turn it is
if(x > 175 && x < 440 && y > 100 && y < 200)
{
switch(Player)
{
case 1:
{
if(Board[0][1] == EMPTY)
{
Board[0][1] = Player1;// set Board[0][1] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[0][1] == EMPTY)
{
Board[0][1] = Player2;// set Board[0][1] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to see if they clicked within a specific rectangle
// this rectangle is the upper left hand corner of the screen
// and is were Board[0][2] is drawn
if(x > 460 && x < 580 && y > 100 && y < 200)
{
switch(Player)
{
case 1:
{
if(Board[0][2] == EMPTY)
{
Board[0][2] = Player1;// set Board[0][2] to Player1's value
NextMove(); // do the NextMove
}
}
break;
case 2:
{
if(Board[0][2] == EMPTY)
{
Board[0][2] = Player2;// set Board[0][2] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to see if they clicked within a rectangle
// its checking to see if they clicked in the the right middle
if(x > 50 && x < 160 && y > 215 && y < 335)
{
switch(Player)
{
case 1:
{
if(Board[1][0] == EMPTY)
{
Board[1][0] = Player1;// set Board[1][0] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[1][0] == EMPTY)
{
Board[1][0] = Player2;// set Board[1][0] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to see if they clicked within a rectangle
// the rectangle is the center of the screen the center sqaure
if(x > 175 && x < 445 && y > 220 && y < 335)
{
switch(Player)
{
case 1:
{
if(Board[1][1] == EMPTY)
{
Board[1][1] = Player1;// set Board[1][1] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[1][1] == EMPTY)
{
Board[1][1] = Player2;// set Board[1][1] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to see if they clicked within a rectangle
// the rectangle is near the middle right of the screen
if(x > 450 && x < 585 && y > 220 && y < 335)
{
switch(Player)
{
case 1:
{
if(Board[1][2] == EMPTY)
{
Board[1][2] = Player1;// set Board[1][2] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[1][2] == EMPTY)
{
Board[1][2] = Player2;// set Board[1][2] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statment to see if they clicked within a rectangle
// the rectangle is near the lower left hand corner of the screen
if(x > 50 && x < 160 && y > 350 && y < 445)
{
switch(Player)
{
case 1:
{
if(Board[2][0] == EMPTY)
{
Board[2][0] = Player1;// set Board[2][0] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[2][0] == EMPTY)
{
Board[2][0] = Player2;// set Board[2][0] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to see if they clicked within a rectangle
// the rectangle is near the bottom middle of the screen
if(x > 175 && x < 445 && y > 350 && y < 430)
{
switch(Player)
{
case 1:
{
if(Board[2][1] == EMPTY)
{
Board[2][1] = Player1;//set Board[2][1] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[2][1] == EMPTY)
{
Board[2][1] = Player2;// set Board[2][1] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
// a if statement to see if they clicked within a rectangle
// this is to see if they clicked the square in the bottom right hand corner
if(x > 450 && x < 585 && y > 350 && y < 445)
{
switch(Player)
{
case 1:
{
if(Board[2][2] == EMPTY)
{
Board[2][2] = Player1;// set Board[2][2] to Player1's value
NextMove();// do the NextMove
}
}
break;
case 2:
{
if(Board[2][2] == EMPTY)
{
Board[2][2] = Player2;// set Board[2][2] to Player2's value
NextMove();// do the NextMove
}
}
break;
}
}
}
}
break;
default:
return DefWindowProc(hwnd,msg,wParam,lParam);// call the default window proccess
}
return (0);
}
int QuiesceFlee(POS *p, int ply, int alpha, int beta, int *pv) {
int best, score, move, new_pv[MAX_PLY];
int fl_check, mv_type;
int is_pv = (beta > alpha + 1);
MOVES m[1];
UNDO u[1];
// Periodically check for timeout, ponderhit or stop command
nodes++;
CheckTimeout();
// Quick exit on a timeout or on a statically detected draw
if (abort_search) return 0;
if (ply) *pv = 0;
if (IsDraw(p) ) return DrawScore(p);
// Retrieving data from transposition table. We hope for a cutoff
// or at least for a move to improve move ordering.
move = 0;
if (TransRetrieve(p->hash_key, &move, &score, alpha, beta, 0, ply))
return score;
// Safeguard against exceeding ply limit
if (ply >= MAX_PLY - 1)
return Eval.Return(p, 1);
// Are we in check? Knowing that is useful when it comes
// to pruning/reduction decisions
fl_check = InCheck(p);
// Init moves and variables before entering main loop
best = -INF;
InitMoves(p, m, move, -1, ply);
// Main loop
while ((move = NextMove(m, &mv_type))) {
p->DoMove(move, u);
if (Illegal(p)) { p->UndoMove(move, u); continue; }
score = -Quiesce(p, ply, -beta, -alpha, new_pv);
p->UndoMove(move, u);
if (abort_search) return 0;
// Beta cutoff
if (score >= beta) {
TransStore(p->hash_key, move, score, LOWER, 0, ply);
return score;
}
// Updating score and alpha
if (score > best) {
best = score;
if (score > alpha) {
alpha = score;
BuildPv(pv, new_pv, move);
}
}
} // end of the main loop
// Return correct checkmate/stalemate score
if (best == -INF)
return InCheck(p) ? -MATE + ply : DrawScore(p);
// Save score in the transposition table
if (*pv) TransStore(p->hash_key, *pv, best, EXACT, 0, ply);
else TransStore(p->hash_key, 0, best, UPPER, 0, ply);
return best;
}
// Algorithme de recherche MinMax avec des coupes Alpha-Beta.
// Ici on considere seulement les prises.
int Quiescence(int ply, int wtm, int alpha, int beta )
{
register int Valeur, AlphaInitiale;
if ( ply >= MAXPLY-1 )
return beta;
iNodes++;
if ( wtm ) {
Valeur = Eval(ply, wtm, alpha, beta);
}
else {
Valeur = -Eval(ply, wtm, alpha, beta);
}
// Remplace si le score est egal au score pour la NULLE.
if ( Valeur == DRAWSCORE )
Valeur = DRAWSCORE+1;
AlphaInitiale = alpha;
if ( Valeur > alpha ) {
if ( Valeur >= beta ) return Valeur;
alpha = Valeur;
pv_length[ply] = ply-1;
}
// On genere toutes les prises.
cb.MoveList[ply].nbmove = 0;
GenMoveAttaque(ply, wtm, cb.MoveList[ply]);
int keep = -1;
// Le materiel.
int iScoreMateriel = cb.ScoreMaterielBlanc-cb.ScoreMaterielNoir;
iScoreMateriel = wtm?iScoreMateriel:-iScoreMateriel;
int delta = alpha-100-iScoreMateriel;
int iScoreGain;
for( int i=0; i<cb.MoveList[ply].nbmove; i++ ) {
// Garder le coup.
bool bGarde = false;
// On cherche seulement les coups qui ramene le materiel proche de alpha.
// ex. Si celui qui jouent vient de se faire prendre une dame et que alpha
// dit que le meilleur score est la perte d'un pion et bien ignorer tout
// les captures qui ramene pas au moins la dame.
if ( ValeurPiece[cb.MoveList[ply].moves[i].Capture] >= delta ) {
if (cb.MoveList[ply].moves[i].Capture == ROI) return beta;
#ifdef USE_SEE
int iScoreCapture = ValeurPiece[cb.MoveList[ply].moves[i].Capture];
iScoreGain = iScoreCapture-ValeurPiece[cb.MoveList[ply].moves[i].Piece];
if ( iScoreGain > 0 ||
iScoreGain >= 0 &&
delta <= 0 ) {
bGarde = true;
}
else {
iScoreGain = Echange(cb.MoveList[ply].moves[i].From, cb.MoveList[ply].moves[i].To, wtm );
if ( iScoreGain >= 0 ) {
bGarde = true;
}
}
#else
bGarde = true;
#endif
}
if ( bGarde ) {
keep++;
cb.MoveList[ply].moves[i].Score = iScoreGain;
memcpy( &cb.MoveList[ply].moves[keep],
&cb.MoveList[ply].moves[i],
sizeof( TMove ) );
}
}
cb.MoveList[ply].nbmove = keep+1;
cb.MoveList[ply].currmove = -1;
cb.MoveList[ply].Tri();
Phase[ply] = CAPTURE_MOVES;
// Maintenant, evaluer chaque coup.
while( NextMove( cb, ply, wtm ) ) {
// On execute le coup.
MakeMove(ply, cb.MoveList[ply].CurrentMove(), wtm);
// Mettre le coup dans le chemin actuel.
cb.CurrentPath.moves[ply] = cb.MoveList[ply].moves[cb.MoveList[ply].currmove];
if (!Check(wtm))
Valeur = -Quiescence(ply+1, !wtm, -beta, -alpha);
cb.MoveList[ply].CurrentMove().Score = Valeur;
// On defait le coup.
UnmakeMove(ply, cb.MoveList[ply].CurrentMove(), wtm);
// Est-il meileur que notre valeur actuelle?
if ( Valeur > alpha ) {
if ( Valeur >= beta ) return Valeur;
pv_length[ply] = pv_length[ply+1];
pv[ply][ply] = cb.CurrentPath.moves[ply];
memcpy(&pv[ply][ply+1], &pv[ply+1][ply], sizeof(TMove)*(pv_length[ply]-ply));
alpha = Valeur;
}
#ifdef DEBUG
Consistence( cb, cb.MoveList[ply].CurrentMove() );
#endif
}
return alpha;
}
int Search(POS *p, int ply, int alpha, int beta, int depth, int was_null, int last_move, int last_capt_sq, int *pv) {
int best, score, null_score, move, new_depth, new_pv[MAX_PLY];
int fl_check, fl_prunable_node, fl_prunable_move, mv_type, reduction;
int is_pv = (beta > alpha + 1);
int mv_tried = 0, quiet_tried = 0, fl_futility = 0;
int mv_played[MAX_MOVES];
int mv_hist_score;
int victim, last_capt;
MOVES m[1];
UNDO u[1];
assert(ply > 0);
// Quiescence search entry point
if (depth <= 0)
return QuiesceChecks(p, ply, alpha, beta, pv);
// Periodically check for timeout, ponderhit or stop command
nodes++;
CheckTimeout();
// Quick exit on a timeout or on a statically detected draw
if (abort_search) return 0;
if (ply) *pv = 0;
if (IsDraw(p)) return DrawScore(p);
// Mate distance pruning
int checkmatingScore = MATE - ply;
if (checkmatingScore < beta) {
beta = checkmatingScore;
if (alpha >= checkmatingScore)
return alpha;
}
int checkmatedScore = -MATE + ply;
if (checkmatedScore > alpha) {
alpha = checkmatedScore;
if (beta <= checkmatedScore)
return beta;
}
// Retrieving data from transposition table. We hope for a cutoff
// or at least for a move to improve move ordering.
move = 0;
if (TransRetrieve(p->hash_key, &move, &score, alpha, beta, depth, ply)) {
// For move ordering purposes, a cutoff from hash is treated
// exactly like a cutoff from search
if (score >= beta) UpdateHistory(p, last_move, move, depth, ply);
// In pv nodes only exact scores are returned. This is done because
// there is much more pruning and reductions in zero-window nodes,
// so retrieving such scores in pv nodes works like retrieving scores
// from slightly lower depth.
if (!is_pv || (score > alpha && score < beta))
return score;
}
// Safeguard against exceeding ply limit
if (ply >= MAX_PLY - 1)
return Eval.Return(p, 1);
// Are we in check? Knowing that is useful when it comes
// to pruning/reduction decisions
fl_check = InCheck(p);
// INTERNAL ITERATIVE DEEPENING - we try to get a hash move to improve move ordering
if (!move && is_pv && depth >= 6 && !fl_check) {
Search(p, ply, alpha, beta, depth - 2, 0, 0, -1, new_pv);
if (abort_search) return 0;
TransRetrieve(p->hash_key, &move, &score, alpha, beta, depth, ply);
}
// Can we prune this node?
fl_prunable_node = !fl_check
&& !is_pv
&& alpha > -MAX_EVAL
&& beta < MAX_EVAL;
// Beta pruning / static null move
if (use_beta_pruning
&& fl_prunable_node
&& depth <= 3
&& !was_null) {
int sc = Eval.Return(p, 1) - 120 * depth; // TODO: Tune me!
if (sc > beta) return sc;
}
// Null move
if (use_nullmove
&& fl_prunable_node
&& depth > 1
&& !was_null
&& MayNull(p)
) {
int eval = Eval.Return(p, 1);
if (eval > beta) {
new_depth = depth - ((823 + 67 * depth) / 256); // simplified Stockfish formula
// omit null move search if normal search to the same depth wouldn't exceed beta
// (sometimes we can check it for free via hash table)
if (TransRetrieve(p->hash_key, &move, &null_score, alpha, beta, new_depth, ply)) {
if (null_score < beta) goto avoid_null;
}
p->DoNull(u);
if (new_depth > 0) score = -Search(p, ply + 1, -beta, -beta + 1, new_depth, 1, 0, -1, new_pv);
else score = -QuiesceChecks(p, ply + 1, -beta, -beta + 1, new_pv);
p->UndoNull(u);
// Verification search (nb. immediate null move within it is prohibited)
if (new_depth > 6 && score >= beta && use_null_verification)
score = Search(p, ply, alpha, beta, new_depth - 5, 1, move, -1, new_pv);
if (abort_search ) return 0;
if (score >= beta) return score;
}
}
avoid_null:
// end of null move code
// Razoring based on Toga II 3.0
if (use_razoring
&& fl_prunable_node
&& !move
&& !was_null
&& !(p->Pawns(p->side) & bbRelRank[p->side][RANK_7]) // no pawns to promote in one move
&& depth <= 3) {
int threshold = beta - razor_margin[depth];
int eval = Eval.Return(p, 1);
if (eval < threshold) {
score = QuiesceChecks(p, ply, alpha, beta, pv);
if (score < threshold) return score;
}
}
// end of razoring code
// Init moves and variables before entering main loop
best = -INF;
InitMoves(p, m, move, Refutation(last_move), ply);
// Main loop
while ((move = NextMove(m, &mv_type))) {
// Gather data about the move
mv_hist_score = history[p->pc[Fsq(move)]][Tsq(move)];
victim = TpOnSq(p, Tsq(move));
if (victim != NO_TP) last_capt = Tsq(move);
else last_capt = -1;
// Set futility pruning flag before the first applicable move is tried
if (mv_type == MV_NORMAL && quiet_tried == 0) {
if (use_futility
&& fl_prunable_node
&& depth <= 6) {
if (Eval.Return(p, 1) + fut_margin[depth] < beta) fl_futility = 1;
}
}
p->DoMove(move, u);
if (Illegal(p)) { p->UndoMove(move, u); continue; }
// Update move statistics
// (needed for reduction/pruning decisions and for updating history score)
mv_played[mv_tried] = move;
mv_tried++;
if (mv_type == MV_NORMAL) quiet_tried++;
// Can we prune this move?
fl_prunable_move = !InCheck(p)
&& (mv_type == MV_NORMAL)
&& (mv_hist_score < hist_limit);
// Set new search depth
new_depth = depth - 1;
// Check extension (pv node or low depth)
if (is_pv || depth < 9) {
new_depth += InCheck(p);
if (is_pv && Tsq(move) == last_capt_sq) new_depth += 1;
}
// Futility pruning
if (fl_futility
&& fl_prunable_move
&& mv_tried > 1) {
p->UndoMove(move, u); continue;
}
// Late move pruning
if (use_lmp
&& fl_prunable_node
&& fl_prunable_move
&& quiet_tried > lmp_limit[depth]
&& depth <= 3
&& MoveType(move) != CASTLE ) {
p->UndoMove(move, u); continue;
}
// Late move reduction
reduction = 0;
if (use_lmr
&& depth >= 2
&& mv_tried > 3
&& alpha > -MAX_EVAL && beta < MAX_EVAL
&& !fl_check
&& fl_prunable_move
&& lmr_size[is_pv][depth][mv_tried] > 0
&& MoveType(move) != CASTLE ) {
// read reduction size from the table
reduction = lmr_size[is_pv][depth][mv_tried];
// increase reduction on bad history score
if (mv_hist_score < 0
&& new_depth - reduction > 2
&& lmr_hist_adjustement)
reduction++;
// reduce search depth
new_depth -= reduction;
}
// a place to come back if reduction looks suspect
re_search:
// PVS
if (best == -INF)
score = -Search(p, ply + 1, -beta, -alpha, new_depth, 0, move, last_capt, new_pv);
else {
score = -Search(p, ply + 1, -alpha - 1, -alpha, new_depth, 0, move, last_capt, new_pv);
if (!abort_search && score > alpha && score < beta)
score = -Search(p, ply + 1, -beta, -alpha, new_depth, 0, move, last_capt, new_pv);
}
// Reduced move scored above alpha - we need to re-search it
if (reduction
&& score > alpha) {
new_depth += reduction;
reduction = 0;
goto re_search;
}
// Undo move
p->UndoMove(move, u);
if (abort_search) return 0;
// Beta cutoff
if (score >= beta) {
if (!fl_check) {
UpdateHistory(p, last_move, move, depth, ply);
for (int mv = 0; mv < mv_tried; mv++)
DecreaseHistory(p, mv_played[mv], depth);
}
TransStore(p->hash_key, move, score, LOWER, depth, ply);
return score;
}
// Updating score and alpha
if (score > best) {
best = score;
if (score > alpha) {
alpha = score;
BuildPv(pv, new_pv, move);
}
}
} // end of the main loop
// Return correct checkmate/stalemate score
if (best == -INF)
return InCheck(p) ? -MATE + ply : DrawScore(p);
// Save score in the transposition table
if (*pv) {
if (!fl_check) {
UpdateHistory(p, last_move, *pv, depth, ply);
for (int mv = 0; mv < mv_tried; mv++)
DecreaseHistory(p, mv_played[mv], depth);
}
TransStore(p->hash_key, *pv, best, EXACT, depth, ply);
} else
TransStore(p->hash_key, 0, best, UPPER, depth, ply);
return best;
}
int SearchRoot(POS *p, int ply, int alpha, int beta, int depth, int *pv) {
int best, score, move, new_depth, new_pv[MAX_PLY];
int fl_check, fl_prunable_move, mv_type, reduction;
int mv_tried = 0, quiet_tried = 0;
int mv_played[MAX_MOVES];
int mv_hist_score;
int victim, last_capt;
int move_change = 0;
fl_has_choice = 0;
MOVES m[1];
UNDO u[1];
// Periodically check for timeout, ponderhit or stop command
nodes++;
CheckTimeout();
// Quick exit
if (abort_search) return 0;
// Retrieving data from transposition table. We hope for a cutoff
// or at least for a move to improve move ordering.
move = 0;
if (TransRetrieve(p->hash_key, &move, &score, alpha, beta, depth, ply)) {
// For move ordering purposes, a cutoff from hash is treated
// exactly like a cutoff from search
if (score >= beta) UpdateHistory(p, -1, move, depth, ply);
// Root node is a pv node, so we return only exact scores
if (score > alpha && score < beta)
return score;
}
// Are we in check? Knowing that is useful when it comes
// to pruning/reduction decisions
fl_check = InCheck(p);
// Init moves and variables before entering main loop
best = -INF;
InitMoves(p, m, move, Refutation(-1), ply);
// Main loop
while ((move = NextMove(m, &mv_type))) {
mv_hist_score = history[p->pc[Fsq(move)]][Tsq(move)];
victim = TpOnSq(p, Tsq(move));
if (victim != NO_TP) last_capt = Tsq(move);
else last_capt = -1;
p->DoMove(move, u);
if (Illegal(p)) { p->UndoMove(move, u); continue; }
// Update move statistics (needed for reduction/pruning decisions)
mv_played[mv_tried] = move;
mv_tried++;
if (mv_tried > 1) fl_has_choice = 1; // we have a choice between at least two root moves
if (depth > 16 && verbose) DisplayCurrmove(move, mv_tried);
if (mv_type == MV_NORMAL) quiet_tried++;
fl_prunable_move = !InCheck(p) && (mv_type == MV_NORMAL);
// Set new search depth
new_depth = depth - 1 + InCheck(p);
// Late move reduction
reduction = 0;
if (use_lmr
&& depth >= 2
&& mv_tried > 3
&& mv_hist_score < hist_limit
&& alpha > -MAX_EVAL && beta < MAX_EVAL
&& !fl_check
&& fl_prunable_move
&& lmr_size[1][depth][mv_tried] > 0
&& MoveType(move) != CASTLE ) {
reduction = lmr_size[1][depth][mv_tried];
// increase reduction on bad history score
if (mv_hist_score < 0
&& new_depth - reduction > 2
&& lmr_hist_adjustement)
reduction++;
new_depth -= reduction;
}
re_search:
// PVS
if (best == -INF)
score = -Search(p, ply + 1, -beta, -alpha, new_depth, 0, move, last_capt, new_pv);
else {
score = -Search(p, ply + 1, -alpha - 1, -alpha, new_depth, 0, move, last_capt, new_pv);
if (!abort_search && score > alpha && score < beta)
score = -Search(p, ply + 1, -beta, -alpha, new_depth, 0, move, last_capt, new_pv);
}
// Reduced move scored above alpha - we need to re-search it
if (reduction && score > alpha) {
new_depth += reduction;
reduction = 0;
goto re_search;
}
p->UndoMove(move, u);
if (abort_search) return 0;
// Beta cutoff
if (score >= beta) {
if (!fl_check) {
UpdateHistory(p, -1, move, depth, ply);
for (int mv = 0; mv < mv_tried; mv++)
DecreaseHistory(p, mv_played[mv], depth);
}
TransStore(p->hash_key, move, score, LOWER, depth, ply);
// Update search time depending on whether the first move has changed
if (depth > 4) {
if (pv[0] != move) Timer.OnNewRootMove();
else Timer.OnOldRootMove();
}
// Change the best move and show the new pv
BuildPv(pv, new_pv, move);
DisplayPv(score, pv);
return score;
}
// Updating score and alpha
if (score > best) {
best = score;
if (score > alpha) {
alpha = score;
// Update search time depending on whether the first move has changed
if (depth > 4) {
if (pv[0] != move) Timer.OnNewRootMove();
else Timer.OnOldRootMove();
}
// Change the best move and show the new pv
BuildPv(pv, new_pv, move);
DisplayPv(score, pv);
}
}
} // end of the main loop
// Return correct checkmate/stalemate score
if (best == -INF)
return InCheck(p) ? -MATE + ply : DrawScore(p);
// Save score in the transposition table
if (*pv) {
if (!fl_check) {
UpdateHistory(p, -1, *pv, depth, ply);
for (int mv = 0; mv < mv_tried; mv++)
DecreaseHistory(p, mv_played[mv], depth);
}
TransStore(p->hash_key, *pv, best, EXACT, depth, ply);
} else
TransStore(p->hash_key, 0, best, UPPER, depth, ply);
return best;
}
