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search.c
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search.c
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#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "shogi.h"
static void hist_add( tree_t * restrict ptree, int ply );
static void hist_good( tree_t * restrict ptree, unsigned int move, int ply,
int depth, int turn );
static int detect_signals( tree_t * restrict ptree );
static int detect_rep( tree_t * restrict ptree, int ply, int turn );
static int rep_type( const tree_t * restrict ptree, int n, int i, int ply,
int turn );
/* #define DBG_SEARCH */
#if defined(DBG_SEARCH)
# define DOut( ... ) if ( dbg_flag ) { out( __VA_ARGS__ ); }
#else
# define DOut( ... )
#endif
int
search( tree_t * restrict ptree, int alpha, int beta, int turn, int depth,
int ply, unsigned int state_node )
{
int value, alpha_old;
if ( ! ptree->nsuc_check[ply] && depth < PLY_INC )
{
return search_quies( ptree, alpha, beta, turn, ply, 1 );
}
#if defined(DBG_SEARCH)
int dbg_flag = 0;
if ( iteration_depth == 3 && ply == 3
&& ! strcmp( str_CSA_move(ptree->current_move[1]), "7776FU" )
&& ! strcmp( str_CSA_move(ptree->current_move[2]), "3334FU" ) )
{
dbg_flag = 1;
Out( "search start (d%.1f %" PRIu64 ")\n",
(double)depth / (double)PLY_INC, ptree->node_searched );
}
#endif
ptree->node_searched++;
if ( ply >= PLY_MAX-1 )
{
value = evaluate( ptree, ply, turn );
if ( alpha < value && value < beta ) { pv_close( ptree, ply, no_rep ); }
MOVE_CURR = MOVE_NA;
return value;
}
#if ! defined(MINIMUM)
if ( ! ( game_status & flag_learning ) )
#endif
{
/* check time and input */
#if defined(TLP)
if ( ! ptree->tlp_id )
#endif
if ( node_next_signal < ++node_last_check && detect_signals( ptree ) )
{
root_abort = 1;
return 0;
}
/* repetitions */
ptree->nrep_tried++;
switch ( detect_rep( ptree, ply, turn ) )
{
case black_superi_rep:
value = turn ? -score_inferior : score_inferior;
if ( alpha < value
&& value < beta ) { pv_close( ptree, ply, black_superi_rep ); }
ptree->nsuperior_rep++;
MOVE_CURR = MOVE_NA;
return value;
case white_superi_rep:
value = turn ? score_inferior : -score_inferior;
if ( alpha < value
&& value < beta ) { pv_close( ptree, ply, white_superi_rep ); }
ptree->nsuperior_rep++;
MOVE_CURR = MOVE_NA;
return value;
case four_fold_rep:
if ( alpha < score_draw
&& score_draw < beta ) { pv_close( ptree, ply, four_fold_rep );}
ptree->nfour_fold_rep++;
MOVE_CURR = MOVE_NA;
return score_draw;
case perpetual_check:
ptree->nperpetual_check++;
MOVE_CURR = MOVE_NA;
return score_foul;
case perpetual_check2:
if ( ply > 4 )
{
ptree->nperpetual_check++;
MOVE_CURR = MOVE_NA;
return -score_foul;
}
break;
}
ptree->nreject_tried++;
if ( rejections_probe( ptree, turn, ply ) )
{
ptree->nreject_done++;
if ( alpha < score_inferior && score_inferior < beta )
{
pv_close( ptree, ply, turn ? white_superi_rep:black_superi_rep );
}
MOVE_CURR = MOVE_NA;
return score_inferior;
}
}
/*
no repetitions. worst situation of this node is checkmate,
and the best is to force checkmate within 1-ply.
*/
alpha_old = alpha;
value = - ( score_mate1ply + 2 - ply );
if ( alpha < value )
{
if ( beta <= value )
{
MOVE_CURR = MOVE_NA;
return value;
}
alpha = value;
}
else {
value = score_mate1ply + 1 - ply;
if ( value <= alpha ) { return value; }
}
#if defined(NO_NULL_PRUNE)
state_node &= ~node_do_null;
#endif
ptree->amove_hash[ply] = 0;
#if ! defined(MINIMUM)
if ( ! ( game_status & flag_learning ) )
#endif
{
/* probe the transposition table */
int tv = hash_probe( ptree, ply, depth, turn, alpha, beta, state_node );
switch ( tv )
{
case value_exact:
if ( alpha < HASH_VALUE )
{
if ( HASH_VALUE < beta ) { pv_close( ptree, ply, hash_hit ); }
else {
MOVE_CURR = ptree->amove_hash[ply];
assert( is_move_valid( ptree, MOVE_CURR, turn ) );
}
}
return HASH_VALUE;
case value_lower:
MOVE_CURR = ptree->amove_hash[ply];
assert( beta <= HASH_VALUE );
assert( ! IsMove(MOVE_CURR)
|| is_move_valid( ptree, MOVE_CURR, turn ) );
if ( beta == alpha_old + 1 ) { return HASH_VALUE; }
break;
case value_upper:
assert( HASH_VALUE <= alpha );
if ( beta == alpha_old + 1 ) { return HASH_VALUE; }
break;
default:
state_node = tv;
}
}
DOut( "\nhash cut passed" );
if ( depth >= REJEC_MIN_DEPTH ) { add_rejections( ptree, turn, ply ); }
if ( ! ptree->nsuc_check[ply] )
{
/* detect a move mates in 3-ply */
if ( ( state_node & node_do_mate )
&& is_mate_in3ply( ptree, turn, ply ) )
{
value = score_mate1ply + 1 - ply;
hash_store( ptree, ply, depth, turn, value_exact, value,
MOVE_CURR, 0 );
if ( alpha < value
&& value < beta ) { pv_close( ptree, ply, mate_search ); }
if ( depth >= REJEC_MIN_DEPTH )
{
sub_rejections( ptree, turn, ply );
}
assert( is_move_valid( ptree, MOVE_CURR, turn ) );
return value;
}
/* null move pruning */
if ( 2*PLY_INC <= depth
&& ( state_node & node_do_null )
&& beta == alpha_old + 1
&& beta <= evaluate( ptree, ply, turn ) )
{
int null_depth, nrep;
null_depth = NullDepth(depth);
nrep = root_nrep + ply - 1;
MOVE_CURR = MOVE_PASS;
ptree->move_last[ply] = ptree->move_last[ply-1];
ptree->stand_pat[ply+1] = (short)( - ptree->stand_pat[ply] );
ptree->nsuc_check[ply+1] = 0;
ptree->rep_board_list[nrep] = HASH_KEY;
ptree->rep_hand_list[nrep] = HAND_B;
ptree->null_pruning_tried++;
value = -search( ptree, -beta, 1-beta, Flip(turn), null_depth, ply+1,
node_do_mate | node_do_recap | node_do_futile );
if ( SEARCH_ABORT )
{
if ( depth >= REJEC_MIN_DEPTH )
{
sub_rejections( ptree, turn, ply );
}
return 0;
}
if ( beta <= value )
{
ptree->null_pruning_done++;
if ( null_depth < PLY_INC )
{
hash_store( ptree, ply, depth, turn, value_lower,
value, MOVE_NA, state_node );
}
if ( depth >= REJEC_MIN_DEPTH )
{
sub_rejections( ptree, turn, ply );
}
DOut( "\nnull move cut!\n" );
assert( ! IsMove(MOVE_CURR)
|| is_move_valid( ptree, MOVE_CURR, turn ) );
return value;
}
DOut( "\nnull passed" );
if ( value == - ( score_mate1ply - ply ) )
{
state_node |= node_mate_threat;
}
}
}
/* recursive iterative-deepening for pv nodes */
if ( ! ptree->amove_hash[ply]
&& depth >= 3*PLY_INC
&& ( ( alpha == root_alpha && beta == root_beta )
|| ( alpha == -root_beta && beta == -root_alpha ) ) )
{
if ( depth >= REJEC_MIN_DEPTH ) { sub_rejections( ptree, turn, ply ); }
value = search( ptree, -score_bound, beta, turn, depth-2*PLY_INC, ply,
node_do_mate | node_do_recap );
if ( SEARCH_ABORT ) { return 0; }
if ( beta <= value && IsMove(MOVE_CURR) )
{
ptree->amove_hash[ply] = MOVE_CURR;
}
else if ( value < beta && ply <= (int)ptree->pv[ply-1].length )
{
assert( -score_bound < value );
ptree->amove_hash[ply] = ptree->pv[ply-1].a[ply];
}
assert( ! ptree->amove_hash[ply]
|| is_move_valid( ptree, ptree->amove_hash[ply], turn ) );
if ( depth >= REJEC_MIN_DEPTH ) { add_rejections( ptree, turn, ply ); }
}
{
int depth_reduced, first_move_expanded, new_depth, extension;
int state_node_new;
ptree->move_last[ply] = ptree->move_last[ply-1];
ptree->anext_move[ply].next_phase = next_move_hash;
ptree->hist_nmove[ply] = 0;
first_move_expanded = 0;
evaluate( ptree, ply, turn );
/* expand all of off-springs */
while ( ptree->nsuc_check[ply]
? gen_next_evasion( ptree, ply, turn )
: gen_next_move( ptree, ply, turn ) ) {
DOut( "\nexpand %s (%" PRIu64 ")",
str_CSA_move(MOVE_CURR), ptree->node_searched );
ptree->nsuc_check[ply+1] = 0U;
state_node_new = ( node_do_mate | node_do_recap | node_do_null
| node_do_futile );
extension = 0;
depth_reduced = 0;
hist_add( ptree, ply );
/* decision of extensions */
if ( turn ? is_move_check_w( ptree, MOVE_CURR )
: is_move_check_b( ptree, MOVE_CURR ) )
{
ptree->check_extension_done++;
ptree->nsuc_check[ply+1]
= (unsigned char)( ptree->nsuc_check[ply-1] + 1U );
extension = EXT_CHECK;
}
else if ( ptree->nsuc_check[ply]
&& ptree->move_last[ply] - ptree->move_last[ply-1] == 1 )
{
ptree->onerp_extension_done++;
extension = EXT_ONEREP;
}
else if ( ! ptree->nsuc_check[ply]
&& ( state_node & node_do_recap )
&& I2To(MOVE_CURR) == I2To(MOVE_LAST)
&& ( MOVE_CURR == ptree->anext_move[ply].move_cap1
|| ( ( ptree->anext_move[ply].value_cap1
< ( ptree->anext_move[ply].value_cap2
+ MT_CAP_PAWN ) )
&& MOVE_CURR == ptree->anext_move[ply].move_cap2 ))
&& ( UToCap(MOVE_LAST)
|| ( I2IsPromote(MOVE_LAST)
&& I2PieceMove(MOVE_LAST) != silver ) ) )
{
ptree->recap_extension_done++;
state_node_new = node_do_null | node_do_mate | node_do_futile;
if ( ! I2IsPromote(MOVE_CURR)
&& I2PieceMove(MOVE_LAST) == UToCap(MOVE_LAST) )
{
extension = EXT_RECAP2;
}
else { extension = EXT_RECAP1; }
}
LimitExtension( extension, ply );
new_depth = depth + extension - PLY_INC;
/* reductions */
if ( PLY_INC <= new_depth
&& ! ( state_node & node_mate_threat )
&& ! ptree->nsuc_check[ply]
&& ! UToCap(MOVE_CURR)
&& ! ( I2IsPromote(MOVE_CURR) && I2PieceMove(MOVE_CURR) != silver )
&& ptree->amove_hash[ply] != MOVE_CURR
&& ptree->killers[ply].no1 != MOVE_CURR
&& ptree->killers[ply].no2 != MOVE_CURR )
{
unsigned int key = phash( MOVE_CURR, turn );
unsigned int good = ptree->hist_good[key] + 1;
unsigned int triedx8 = ( ptree->hist_tried[key] + 2 ) * 8U;
if ( beta != alpha_old + 1 ) {
if ( good * 62U < triedx8 ) { depth_reduced = PLY_INC * 4/2; }
else if ( good * 46U < triedx8 ) { depth_reduced = PLY_INC * 3/2; }
else if ( good * 34U < triedx8 ) { depth_reduced = PLY_INC * 2/2; }
else if ( good * 19U < triedx8 ) { depth_reduced = PLY_INC * 1/2; }
} else {
if ( good * 62U < triedx8 ) { depth_reduced = PLY_INC * 4/2; }
else if ( good * 46U < triedx8 ) { depth_reduced = PLY_INC * 3/2; }
else if ( good * 30U < triedx8 ) { depth_reduced = PLY_INC * 2/2; }
else if ( good * 12U < triedx8 ) { depth_reduced = PLY_INC * 1/2; }
}
new_depth -= depth_reduced;
}
/* futility pruning */
if ( ! ptree->nsuc_check[ply+1]
&& ! ptree->nsuc_check[ply]
&& new_depth < 3*PLY_INC )
{
int diff = estimate_score_diff( ptree, MOVE_CURR, turn );
int bound = alpha;
if ( 2*PLY_INC <= new_depth ) { bound -= EFUTIL_MG2; }
else if ( 1*PLY_INC <= new_depth ) { bound -= EFUTIL_MG1; }
if ( eval_max_score( ptree, MOVE_CURR, ptree->stand_pat[ply],
turn, diff ) <= bound )
{
first_move_expanded += 1;
continue;
}
}
DOut( ", futil passed" );
MakeMove( turn, MOVE_CURR, ply );
if ( I2From(MOVE_CURR) < nsquare
&& ! ptree->nsuc_check[ply]
&& InCheck(turn) )
{
UnMakeMove( turn, MOVE_CURR, ply );
continue;
}
if ( ! ptree->nsuc_check[ply+1] && ! ptree->nsuc_check[ply] )
{
evaluate( ptree, ply+1, Flip(turn) );
assert( ptree->stand_pat[ply] != score_bound );
/* futility pruning */
if ( ( new_depth < PLY_INC && - ptree->stand_pat[ply+1] <= alpha )
|| ( new_depth < 2*PLY_INC
&& - ptree->stand_pat[ply+1] <= alpha - EFUTIL_MG1 )
|| ( new_depth < 3*PLY_INC
&& - ptree->stand_pat[ply+1] <= alpha - EFUTIL_MG2 ) )
{
first_move_expanded += 1;
UnMakeMove( turn, MOVE_CURR, ply );
continue;
}
}
if ( depth_reduced )
{
value = -search( ptree, -alpha-1, -alpha, Flip(turn), new_depth,
ply + 1, state_node_new );
if ( ! SEARCH_ABORT && alpha < value )
{
new_depth += depth_reduced;
value = -search( ptree, -beta, -alpha, Flip(turn), new_depth,
ply+1, state_node_new );
}
}
else if ( ! first_move_expanded )
{
value = -search( ptree, -beta, -alpha, Flip(turn), new_depth, ply+1,
state_node_new );
}
else {
value = -search( ptree, -alpha-1, -alpha, Flip(turn), new_depth,
ply + 1, state_node_new );
if ( ! SEARCH_ABORT && alpha < value && beta != alpha+1 )
{
value = -search( ptree, -beta, -alpha, Flip(turn), new_depth,
ply + 1, state_node_new );
}
}
if ( SEARCH_ABORT )
{
UnMakeMove( turn, MOVE_CURR, ply );
if ( depth >= REJEC_MIN_DEPTH )
{
sub_rejections( ptree, turn, ply );
}
return 0;
}
UnMakeMove( turn, MOVE_CURR, ply );
if ( alpha < value )
{
if ( new_depth < PLY_INC
&& ! ptree->nsuc_check[ply+1]
&& ptree->stand_pat[ply] != score_bound )
{
check_futile_score_quies( ptree, MOVE_CURR,
ptree->stand_pat[ply],
-ptree->stand_pat[ply+1], turn );
}
if ( beta <= value )
{
DOut( ", beta cut (%" PRIu64 ")\n", ptree->node_searched );
hash_store( ptree, ply, depth, turn, value_lower, value,
MOVE_CURR, state_node );
hist_good( ptree, MOVE_CURR, ply, depth, turn );
ptree->fail_high++;
if ( ! first_move_expanded ) { ptree->fail_high_first++; }
if ( depth >= REJEC_MIN_DEPTH )
{
sub_rejections( ptree, turn, ply );
}
assert( is_move_valid( ptree, MOVE_CURR, turn ) );
return value;
}
}
if ( alpha < value ) { alpha = value; }
first_move_expanded += 1;
#if defined(TLP)
if ( ! ( ptree->nsuc_check[ply]
&& ptree->move_last[ply] - ptree->move_last[ply-1] < 4 )
&& tlp_idle
&& ( ( iteration_depth < 11 && PLY_INC * 3 <= depth )
|| PLY_INC * 4 <= depth ) )
{
ptree->tlp_beta = (short)beta;
ptree->tlp_best = (short)alpha;
ptree->tlp_depth = (unsigned char)depth;
ptree->tlp_state_node = (unsigned char)state_node;
ptree->tlp_turn = (char)turn;
ptree->tlp_ply = (char)ply;
if ( tlp_split( ptree ) )
{
if ( SEARCH_ABORT ) { return 0; }
value = ptree->tlp_best;
if ( alpha < value )
{
if ( beta <= value )
{
if ( depth >= REJEC_MIN_DEPTH )
{
sub_rejections( ptree, turn, ply );
}
hash_store( ptree, ply, depth, turn, value_lower,
value, MOVE_CURR, state_node );
hist_good( ptree, MOVE_CURR, ply, depth, turn );
ptree->fail_high++;
assert( is_move_valid( ptree, MOVE_CURR, turn ) );
return value;
}
alpha = value;
}
break;
}
}
#endif
}
DOut( "\nall searched (%" PRIu64 ")\n", ptree->node_searched );
if ( depth >= REJEC_MIN_DEPTH ) { sub_rejections( ptree, turn, ply ); }
if ( ! first_move_expanded )
{
#if ! defined(MINIMUM)
if ( (int)I2From( ptree->current_move[ply-1] ) == Drop2From( pawn ) )
{
out_warning( "A checkmate by dropping pawn!!" );
}
#endif
if ( alpha != alpha_old ) { pv_close( ptree, ply, 0 ); }
return alpha;
}
if ( alpha <= - ( score_mate1ply + 2 - ply ) )
{
#if ! defined(MINIMUM)
out_warning( "A node returns a value lower than mate." );
#endif
if ( alpha_old < -score_inferior && -score_inferior < beta )
{
pv_close( ptree, ply, turn ? black_superi_rep : white_superi_rep );
}
MOVE_CURR = MOVE_NA;
return -score_inferior;
}
if ( alpha != alpha_old )
{
hist_good( ptree, ptree->pv[ply].a[ply], ply, depth, turn );
pv_copy( ptree, ply );
#if ! defined(MINIMUM)
if ( ! ( game_status & flag_learning ) )
#endif
{
hash_store( ptree, ply, depth, turn, value_exact, alpha,
ptree->pv[ply].a[ply], state_node );
}
}
else {
hash_store( ptree, ply, depth, turn, value_upper, alpha, MOVE_NA,
state_node );
}
}
return alpha;
}
#if defined(TLP)
int
tlp_search( tree_t * restrict ptree, int alpha, int beta, int turn,
int depth, int ply, unsigned int state_node )
{
int value, new_depth, extension, state_node_new, iret, depth_reduced;
int alpha_old;
assert( depth >= 3*PLY_INC );
alpha_old = alpha;
for ( ;; ) {
lock( & ptree->tlp_ptree_parent->tlp_lock );
if ( ptree->nsuc_check[ply] )
{
iret = gen_next_evasion( ptree->tlp_ptree_parent, ply, turn );
}
else { iret = gen_next_move( ptree->tlp_ptree_parent, ply, turn ); }
MOVE_CURR = ptree->tlp_ptree_parent->current_move[ply];
hist_add( ptree->tlp_ptree_parent, ply );
unlock( & ptree->tlp_ptree_parent->tlp_lock );
if ( ! iret ) { break; }
ptree->nsuc_check[ply+1] = 0U;
state_node_new = ( node_do_mate | node_do_recap | node_do_null
| node_do_futile );
extension = 0;
depth_reduced = 0;
if ( turn ? is_move_check_w( ptree, MOVE_CURR )
: is_move_check_b( ptree, MOVE_CURR ) )
{
ptree->check_extension_done++;
ptree->nsuc_check[ply+1]
= (unsigned char)( ptree->nsuc_check[ply-1] + 1U );
extension = EXT_CHECK;
}
else if ( ! ptree->nsuc_check[ply]
&& ( state_node & node_do_recap )
&& I2To(MOVE_CURR) == I2To(MOVE_LAST)
&& ( MOVE_CURR == ptree->anext_move[ply].move_cap1
|| ( ( ptree->anext_move[ply].value_cap1
< ptree->anext_move[ply].value_cap2 + MT_CAP_PAWN )
&& MOVE_CURR == ptree->anext_move[ply].move_cap2 ) )
&& ( UToCap(MOVE_LAST)
|| ( I2IsPromote(MOVE_LAST)
&& I2PieceMove(MOVE_LAST) != silver ) ) )
{
ptree->recap_extension_done++;
state_node_new = node_do_null | node_do_mate | node_do_futile;
if ( ! I2IsPromote(MOVE_CURR)
&& I2PieceMove(MOVE_LAST) == UToCap(MOVE_LAST) )
{
extension = EXT_RECAP2;
}
else { extension = EXT_RECAP1; }
}
LimitExtension( extension, ply );
new_depth = depth + extension - PLY_INC;
/* reductions */
if ( ! ( state_node & node_mate_threat )
&& ! ptree->nsuc_check[ply]
&& ! UToCap(MOVE_CURR)
&& ! ( I2IsPromote(MOVE_CURR) && I2PieceMove(MOVE_CURR) != silver )
&& ptree->killers[ply].no1 != MOVE_CURR
&& ptree->killers[ply].no2 != MOVE_CURR )
{
unsigned int key = phash( MOVE_CURR, turn );
unsigned int good = ptree->hist_good[key] + 1;
unsigned int triedx8 = ( ptree->hist_tried[key] + 2 ) * 8U;
if ( beta != alpha_old + 1 ) {
if ( good * 62U < triedx8 ) { depth_reduced = PLY_INC * 4/2; }
else if ( good * 46U < triedx8 ) { depth_reduced = PLY_INC * 3/2; }
else if ( good * 34U < triedx8 ) { depth_reduced = PLY_INC * 2/2; }
else if ( good * 19U < triedx8 ) { depth_reduced = PLY_INC * 1/2; }
} else {
if ( good * 62U < triedx8 ) { depth_reduced = PLY_INC * 4/2; }
else if ( good * 46U < triedx8 ) { depth_reduced = PLY_INC * 3/2; }
else if ( good * 30U < triedx8 ) { depth_reduced = PLY_INC * 2/2; }
else if ( good * 12U < triedx8 ) { depth_reduced = PLY_INC * 1/2; }
}
new_depth -= depth_reduced;
}
if ( ! ptree->nsuc_check[ply+1]
&& ! ptree->nsuc_check[ply]
&& new_depth < 3*PLY_INC )
{
int diff = estimate_score_diff( ptree, MOVE_CURR, turn );
int bound = alpha;
if ( 2*PLY_INC <= new_depth ) { bound -= EFUTIL_MG2; }
else if ( 1*PLY_INC <= new_depth ) { bound -= EFUTIL_MG1; }
if ( eval_max_score( ptree, MOVE_CURR, ptree->stand_pat[ply],
turn, diff ) <= bound )
{
continue;
}
}
MakeMove( turn, MOVE_CURR, ply );
if ( I2From(MOVE_CURR) < nsquare
&& ! ptree->nsuc_check[ply]
&& InCheck(turn) )
{
UnMakeMove( turn, MOVE_CURR, ply );
continue;
}
if ( ! ptree->nsuc_check[ply+1] && ! ptree->nsuc_check[ply] )
{
evaluate( ptree, ply+1, Flip(turn) );
assert( ptree->stand_pat[ply] != score_bound );
/* futility pruning */
if ( ( new_depth < PLY_INC && - ptree->stand_pat[ply+1] <= alpha )
|| ( new_depth < 2*PLY_INC
&& - ptree->stand_pat[ply+1] <= alpha - EFUTIL_MG1 )
|| ( new_depth < 3*PLY_INC
&& - ptree->stand_pat[ply+1] <= alpha - EFUTIL_MG2 ) )
{
UnMakeMove( turn, MOVE_CURR, ply );
continue;
}
}
value = -search( ptree, -alpha-1, -alpha, Flip(turn), new_depth,
ply + 1, state_node_new );
if ( ! SEARCH_ABORT && alpha < value )
{
if ( ! depth_reduced && beta != alpha+1 )
{
value = -search( ptree, -beta, -alpha, Flip(turn), new_depth,
ply + 1, state_node_new );
}
else if ( depth_reduced )
{
new_depth += depth_reduced;
value = -search( ptree, -beta, -alpha, Flip(turn), new_depth,
ply + 1, state_node_new );
}
}
UnMakeMove( turn, MOVE_CURR, ply );
if ( SEARCH_ABORT ) { return 0; }
if ( alpha < value ) {
alpha = value;
if ( beta <= value ) {
int num;
lock( &tlp_lock );
if ( ptree->tlp_abort )
{
unlock( &tlp_lock );
return 0;
}
tlp_nabort += 1;
for ( num = 0; num < tlp_max; num++ )
if ( ptree->tlp_ptree_parent->tlp_ptrees_sibling[num]
&& num != ptree->tlp_id )
tlp_set_abort( ptree->tlp_ptree_parent->tlp_ptrees_sibling[num] );
unlock( &tlp_lock );
return value;
}
}
}
return alpha;
}
#endif /* TLP */
static int
detect_signals( tree_t * restrict ptree )
{
unsigned int tnow, telapsed, tpondered, tsearched, tcount, tlimit, tmax;
unsigned int tmax_limit_count, tlimit_count, u;
int iret, easy_time, last_value, stable;
if ( ! ( game_status & flag_nopeek ) )
{
/* peek input-buffer to find a command */
iret = next_cmdline( 0 );
if ( iret == -1 )
{
game_status |= flag_search_error;
return 1;
}
else if ( iret == -2 )
{
out_warning( "%s", str_error );
ShutdownClient;
}
else if ( game_status & flag_quit ) { return 1; } /* EOF */
else if ( iret )
{
/* a command is found */
iret = procedure( ptree );
if ( iret == -1 )
{
game_status |= flag_search_error;
next_cmdline( 1 );
return 1;
}
else if ( iret == -2 )
{
out_warning( "%s", str_error );
next_cmdline( 1 );
ShutdownClient;
}
else if ( iret == 1 ) { next_cmdline( 1 ); }
if ( game_status & ( flag_quit | flag_quit_ponder
| flag_move_now | flag_suspend ) )
{
return 1;
}
}
}
/* check conditions of search-abortion, and obtain tnow and elapsed */
if ( node_limit <= ptree->node_searched ) { return 1; }
if ( get_elapsed( &tnow ) < 0 )
{
game_status |= flag_search_error;
return 1;
}
/* keep my connection alive */
#if defined(CSA_LAN)
if ( sckt_csa != SCKT_NULL
&& SEC_KEEP_ALIVE * 1000U < tnow - time_last_send
&& sckt_out( sckt_csa, "\n" ) < 0 )
{
game_status |= flag_search_error;
return 1;
}
#endif
#if defined(MNJ_LAN)
if ( sckt_mnj != SCKT_NULL && 500U < tnow - time_last_send )
{
uint64_t nodes;
# if defined(TLP)
lock( &tlp_lock );
nodes = tlp_count_node( tlp_atree_work );
unlock( &tlp_lock );
# else
nodes = ptree->node_searched;
# endif
if ( sckt_out( sckt_mnj, "pid=%d n=%" PRIu64 "\n", mnj_posi_id,
nodes ) < 0 )
{
game_status |= flag_search_error;
return 1;
}
}
#endif
/* shortening the time limit by depth */
if ( time_limit != UINT_MAX
&& sec_limit_depth < PLY_MAX
&& iteration_depth + 10 >= (int)sec_limit_depth )
{
if ( iteration_depth + 0 >= (int)sec_limit_depth ) { u = 1U; }
else if ( iteration_depth + 1 >= (int)sec_limit_depth ) { u = 3U; }
else if ( iteration_depth + 2 >= (int)sec_limit_depth ) { u = 7U; }
else if ( iteration_depth + 3 >= (int)sec_limit_depth ) { u = 15U; }
else if ( iteration_depth + 4 >= (int)sec_limit_depth ) { u = 31U; }
else if ( iteration_depth + 5 >= (int)sec_limit_depth ) { u = 63U; }
else if ( iteration_depth + 6 >= (int)sec_limit_depth ) { u = 127U; }
else if ( iteration_depth + 7 >= (int)sec_limit_depth ) { u = 255U; }
else if ( iteration_depth + 8 >= (int)sec_limit_depth ) { u = 511U; }
else if ( iteration_depth + 9 >= (int)sec_limit_depth ) { u = 1023U; }
else { u = 2047U; }
tlimit = u * 1000U + 1000U - time_response;
tmax = u * 5000U + 1000U - time_response;
if ( tlimit > time_limit ) { tlimit = time_limit; }
if ( tmax > time_max_limit ) { tmax = time_max_limit; }
}
else {
tlimit = time_limit;
tmax = time_max_limit;
}
telapsed = tnow - time_turn_start;
tpondered = time_turn_start - time_start;
tsearched = tnow - time_start;
easy_time = 0;
last_value = root_turn ? -last_root_value : last_root_value;
stable = ( tlimit != UINT_MAX
&& ( ( root_alpha == root_value && ! root_nfail_low )
|| last_pv.type == four_fold_rep
|| ( root_nfail_high
&& root_value + MT_CAP_DRAGON/8 >= last_value ) ) );
if ( tlimit != tmax )
{
tcount = tsearched;
tmax_limit_count = tmax;
tlimit_count = tlimit;
}
else {
tcount = telapsed;
tmax_limit_count = tmax + tpondered;
tlimit_count = tlimit + tpondered;
}
if ( ! ( game_status & flag_pondering )
&& root_nmove == 1
&& telapsed > 2000U - time_response ) { return 1; }
if ( tcount > tmax ) { return 1; }
if ( stable && tcount > tlimit ) { return 1; }
if ( stable
&& ( tmax_limit_count * 3U < ( time_last_search - time_start ) * 5U ) )
{
#if defined(DBG_EASY)
if ( ! easy_move )
{
Out( " The search can be terminated "
"before it reaches time-limit.\n" );
easy_move = ptree->pv[0].a[1];
}
#else
Out( " The search is terminated before it reaches time-limit.\n" );
return 1;
#endif
}
if ( stable
&& easy_abs > abs( last_value )
&& easy_min < last_value - easy_value
&& easy_max > last_value - easy_value )
{
u = tlimit_count / 5U;
if ( u < tpondered ) { ; }
else if ( u - tpondered < 2000U - time_response )
{
u = tpondered + 2000U - time_response;
}
else {
u = ( ( u - tpondered ) / 1000U + 1U ) * 1000U
+ tpondered - time_response;
}
if ( tsearched > u )
{
Out( " The root move %s counted as easy!!\n",
str_CSA_move(root_move_list[0].move) );
#if defined(DBG_EASY)
easy_move = ptree->pv[0].a[1];
easy_abs = 0;
#else
return 1;
#endif
}
else if ( tsearched + 500U > u ) { easy_time = 1; }
}