Add forgotten dfpn files
[bonanza.git] / dfpn.c
diff --git a/dfpn.c b/dfpn.c
new file mode 100644 (file)
index 0000000..b735b73
--- /dev/null
+++ b/dfpn.c
@@ -0,0 +1,870 @@
+#if defined(DFPN)
+
+#include <limits.h>
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include "shogi.h"
+#include "dfpn.h"
+
+dfpn_hash_entry_t * restrict dfpn_hash_tbl = NULL;
+unsigned int dfpn_hash_age;
+unsigned int dfpn_hash_mask;
+
+#if defined(DFPN_DBG)
+int dbg_flag = 1;
+static void CONV dbg_out_move_seq( const node_t * restrict nodes, int ply );
+static void CONV dbg_min_delta_c( const node_t * restrict pnode, int ply );
+static void CONV dbg_sum_phi_c( const node_t * restrict pnode, int ply );
+static void CONV dbg_nodes( const node_t * restrict pnode, int ply );
+#endif
+
+
+static int CONV useless_delta_ticking( node_t * restrict pnode );
+static unsigned int CONV min_delta_c( const node_t * restrict pnode );
+static unsigned int CONV sum_phi_c( const node_t * restrict pnode );
+static int CONV init_children( tree_t * restrict ptree,
+                              dfpn_tree_t * restrict pdfpn_tree, int ply );
+static int CONV mid( tree_t * restrict ptree,
+                    dfpn_tree_t * restrict pdfpn_tree, int ply );
+static void CONV select_child( const tree_t * restrict ptree,
+                              node_t * restrict pnode_c,
+                              unsigned int * restrict pphi_c,
+                              unsigned int * restrict pdelta_c,
+                              unsigned int * restrict pdelta_2 );
+static void CONV num2str( char buf[16], unsigned int num );
+
+#if defined(TLP)
+static dfpn_tree_t dfpn_tree[ TLP_MAX_THREADS ];
+#else
+static dfpn_tree_t dfpn_tree;
+#endif
+
+int CONV
+dfpn( tree_t * restrict ptree, int turn, int ply )
+{
+  dfpn_tree_t * restrict pdfpn_tree;
+  node_t * restrict pnode;
+  float fcpu_percent, fnps, fsat;
+  unsigned int cpu0, cpu1, elapse0, elapse1, u;
+  int iret, i;
+  
+  if ( get_cputime( &cpu0 )    < 0 ) { return -1; }
+  if ( get_elapsed( &elapse0 ) < 0 ) { return -1; }
+
+  u =  node_per_second / 16U;
+  if      ( u > TIME_CHECK_MAX_NODE ) { u = TIME_CHECK_MAX_NODE; }
+  else if ( u < TIME_CHECK_MIN_NODE ) { u = TIME_CHECK_MIN_NODE; }
+  node_next_signal = u;
+  node_last_check  = 0;
+  root_abort       = 0;
+  time_max_limit   = UINT_MAX;
+  time_limit       = UINT_MAX;
+  game_status     &= ~( flag_move_now | flag_suspend | flag_search_error );
+  game_status     |= flag_thinking;
+
+#if defined(TLP)
+  pdfpn_tree = &dfpn_tree[ptree->tlp_id];
+#else
+  pdfpn_tree = &dfpn_tree;
+#endif
+  ptree->node_searched = 0;
+
+  pdfpn_tree->root_ply     = ply;
+  pdfpn_tree->turn_or      = turn;
+  pdfpn_tree->sum_phi_max  = 0;
+  pdfpn_tree->node_limit   = 50000000;
+
+  pnode = pdfpn_tree->anode + ply;
+  pnode->phi           = INF_1;
+  pnode->delta         = INF_1;
+  pnode->turn          = turn;
+  pnode->children      = pdfpn_tree->child_tbl;
+  pnode->new_expansion = 1;
+
+  assert( 1 <= ply );
+  assert( pdfpn_tree->node_limit < DFPN_NODES_MASK );
+  iret = mid( ptree, pdfpn_tree, ply );
+  if ( 0 <= iret
+       && pnode->phi   != INF
+       && pnode->delta != INF )
+    {
+      char buf1[16], buf2[16];
+
+      num2str( buf1, pnode->phi );
+      num2str( buf2, pnode->delta );
+      Out( "Research [%s:%s]\n", buf1, buf2 );
+      pnode->phi   = INF;
+      pnode->delta = INF;
+      iret = mid( ptree, pdfpn_tree, ply );
+    }
+
+  game_status &= ~flag_thinking;
+
+  if ( game_status & flag_search_error ) { return -1; }
+
+  if  ( iret < 0 )
+    {
+      DFPNOut( "UNSOLVED %d\n", iret );
+      switch ( iret ) {
+      case DFPN_ERRNO_MAXNODE:  Out( "RESULT: MAX NODE\n" );      break;
+      case DFPN_ERRNO_MAXPLY:   Out( "RESULT: MAX PLY\n" );       break;
+      case DFPN_ERRNO_SUMPHI:   Out( "RESULT: MAX SUM_PHI\n" );   break;
+      case DFPN_ERRNO_DELTA2P:  Out( "RESULT: MAX DELTA2+1\n" );  break;
+      default:
+       assert( DFPN_ERRNO_SIGNAL == iret );
+        Out( "RESULT: SIGNAL\n" );
+       break;
+      }
+    }
+  else if ( pnode->delta == INF )
+    {
+      const char *str;
+      for ( i = 0; i < pnode->nmove && pnode->children[i].phi != INF; i++ );
+      assert( i < pnode->nmove );
+      str = str_CSA_move(pnode->children[i].move);
+      Out( "RESULT: WIN %s\n", str );
+      DFPNOut( "WIN %s\n", str );
+    }
+  else {
+    Out( "RESULT: LOSE\n" );
+    DFPNOut( "LOSE\n" );
+  }
+
+  fsat = dfpn_hash_sat();
+  if ( 3.0 < fsat )
+    {
+      dfpn_hash_age += 1U;
+      dfpn_hash_age &= DFPN_AGE_MASK;
+    }
+
+  if ( get_cputime( &cpu1 )    < 0 ) { return -1; }
+  if ( get_elapsed( &elapse1 ) < 0 ) { return -1; }
+  fcpu_percent     = 100.0F * (float)( cpu1 - cpu0 );
+  fcpu_percent    /= (float)( elapse1 - elapse0 + 1U );
+  fnps             = 1000.0F * (float)ptree->node_searched;
+  fnps            /= (float)( elapse1 - elapse0 + 1U );
+  node_per_second  = (unsigned int)( fnps + 0.5 );
+
+  Out( "n=%" PRIu64 " sat=%3.1f%%", ptree->node_searched, fsat );
+  Out( " age=%u sum_phi=%u", dfpn_hash_age, pdfpn_tree->sum_phi_max );
+  Out( " time=%.2f cpu=%.1f%% nps=%.2fK\n",
+       (float)( elapse1 - elapse0 + 1U ) / 1000.0F,
+       fcpu_percent, fnps / 1e3F );
+    
+  Out( "\n" );
+
+  return 1;
+}
+
+
+static void CONV
+num2str( char buf[16], unsigned int num )
+{
+  if      ( num == INF )   { snprintf( buf, 16, "inf" ); }
+  else if ( num == INF_1 ) { snprintf( buf, 16, "inf-1" ); }
+  else                     { snprintf( buf, 16, "%u", num ); }
+  buf[15] = '\0';
+}
+
+
+static int CONV
+mid( tree_t * restrict ptree, dfpn_tree_t * restrict pdfpn_tree, int ply )
+{
+  node_t * restrict pnode = pdfpn_tree->anode + ply;
+  uint64_t node_searched0;
+
+#if defined(DFPN_DBG)
+  if ( ptree->node_searched >= 1000000 ) { dbg_flag = 1; }
+  DOut( ply, "MID START [%u,%u]",
+       pnode->phi, pnode->delta );
+  dbg_out_move_seq( pdfpn_tree->anode, ply );
+#endif
+
+  node_searched0 = ptree->node_searched;
+  
+  if ( pdfpn_tree->node_limit
+       <= ++ptree->node_searched ) { return DFPN_ERRNO_MAXNODE; }
+  
+#if ! defined(MINIMUM)
+  if ( ! ( game_status & flag_learning ) )
+#endif
+#if defined(TLP)
+    if ( ! ptree->tlp_id )
+#endif
+      if ( node_next_signal < ++node_last_check && detect_signals( ptree ) )
+       {
+         return DFPN_ERRNO_SIGNAL;
+       }
+  
+  if ( PLY_MAX-4 < ply ) { return DFPN_ERRNO_MAXPLY; }
+  
+  if ( init_children( ptree, pdfpn_tree, ply ) )
+    {
+      pnode->phi   = 0;
+      pnode->delta = INF;
+      pnode->nodes = 1;
+      dfpn_hash_store( ptree, pdfpn_tree, ply );
+      DOut( ply, "MID END: WIN\n" );
+      return 1;
+    }
+  else if ( ! pnode->nmove )
+    {
+      pnode->phi   = INF;
+      pnode->delta = 0;
+      pnode->nodes = 1;
+      dfpn_hash_store( ptree, pdfpn_tree, ply );
+      DOut( ply, "MID END: LOSE\n" );
+      return 1;
+    }
+
+  DOut( ply, "NMOVE: %d", pnode->nmove );
+  pnode->hash_key = HASH_KEY;
+  pnode->hand_b   = HAND_B;
+
+  for ( ;; ) {
+
+    node_t * restrict pnode_c = pdfpn_tree->anode + ply + 1;
+    unsigned int delta_c, phi_c, delta_2;
+    unsigned int delta_2p1;
+    int iret;
+
+    pnode->min_delta = min_delta_c( pnode );
+    pnode->sum_phi   = sum_phi_c( pnode );
+    if ( pnode->sum_phi == UINT_MAX ) { return DFPN_ERRNO_SUMPHI; }
+
+    if ( pdfpn_tree->sum_phi_max < pnode->sum_phi && pnode->sum_phi < INF_1 )
+      {
+       pdfpn_tree->sum_phi_max = pnode->sum_phi;
+      }
+
+#if defined(DFPN_DBG)
+    dbg_nodes( pnode, ply );
+    dbg_min_delta_c( pnode, ply );
+    dbg_sum_phi_c( pnode, ply );
+#endif
+    
+    if ( pnode->phi <= pnode->min_delta
+        || pnode->delta <= pnode->sum_phi ) { break; }
+
+
+    DOut( ply, "PROGRESS: [%u/%u,%u/%u] %u\n",
+         pnode->min_delta, pnode->phi, pnode->sum_phi, pnode->delta, INF );
+    
+    select_child( ptree, pnode, &phi_c, &delta_c, &delta_2 );
+    assert( pdfpn_tree->root_ply == ply
+           || ! pnode->children[pnode->icurr_c].is_loop );
+
+    if ( useless_delta_ticking( pnode ) )
+      {
+       DOut( ply, "USELESS DELTA TICKING, DELTA_2=%u", pnode->phi );
+       delta_2 = pnode->phi;
+      }
+
+    if      ( phi_c        == INF_1 ) { pnode_c->phi = INF; }
+    else if ( pnode->delta >= INF_1 ) { pnode_c->phi = INF_1; }
+    else {
+      assert( phi_c != INF && pnode->sum_phi <= pnode->delta + phi_c );
+      pnode_c->phi = pnode->delta + phi_c - pnode->sum_phi;
+    }
+
+    if ( delta_c == INF_1 ) { pnode_c->delta = INF; }
+    else {
+      if      ( INF_1 - 1 == delta_2 ) { return DFPN_ERRNO_DELTA2P; }
+      else if ( INF_1     <= delta_2 ) { delta_2p1 = delta_2; }
+      else                             { delta_2p1 = delta_2 + 1; }
+
+      pnode_c->delta = delta_2p1 < pnode->phi ? delta_2p1 : pnode->phi;
+    }
+
+    pnode_c->turn          = Flip(pnode->turn);
+    pnode_c->children      = pnode->children + pnode->nmove;
+
+    if ( pnode->children[pnode->icurr_c].nodes == 0 )
+      {
+       pnode_c->new_expansion = 1;
+      }
+    else { pnode_c->new_expansion = 0; }
+
+    MakeMove( pnode->turn, pnode->children[pnode->icurr_c].move, ply );
+
+    iret = mid( ptree, pdfpn_tree, ply+1 );
+
+    UnMakeMove( pnode->turn, pnode->children[pnode->icurr_c].move, ply );
+
+    if ( SEARCH_ABORT ) { return iret; }
+    if ( iret < 0 )     { return iret; }
+
+    pnode->new_expansion                     += pnode_c->new_expansion;
+    pnode->children[pnode->icurr_c].expanded  = pnode_c->new_expansion;
+
+    dfpn_hash_probe( pdfpn_tree, &pnode->children[pnode->icurr_c], ply,
+                    Flip(pnode->turn) );
+  }
+
+  pnode->phi   = pnode->min_delta;
+  pnode->delta = pnode->sum_phi;
+  pnode->nodes = ptree->node_searched - node_searched0;
+  dfpn_hash_store( ptree, pdfpn_tree, ply );
+
+  DOut( ply, "MID END [%u,%u]\n", pnode->min_delta, pnode->sum_phi );
+  return 1;
+}
+
+
+static int CONV
+useless_delta_ticking( node_t * restrict pnode )
+{
+  int i, n;
+
+  n = pnode->nmove;
+  for ( i = 0; i < n; i++ )
+    {
+      if ( pnode->phi <= pnode->children[i].delta )   { continue; }
+      if ( pnode->children[i].is_weak == weak_chuai ) { continue; }
+      if ( pnode->children[i].is_delta_loop )         { continue; }
+      if ( pnode->children[i].expanded == 0 )         { continue; }
+      if ( 2000U < pnode->children[i].delta )         { continue; }
+
+      return 0;
+    }
+
+  return 1;
+}
+
+
+static int CONV
+init_children( tree_t * restrict ptree, dfpn_tree_t * restrict pdfpn_tree,
+              int ply )
+{
+  node_t * restrict pnode = pdfpn_tree->anode + ply;
+  const unsigned int *plast, *pmove;
+  unsigned int amove[MAX_NMOVE];
+  int ip, sq_king, n;
+  
+  n = 0;
+  
+  if ( pdfpn_tree->turn_or == pnode->turn ) {
+
+    sq_king = pnode->turn ? SQ_BKING : SQ_WKING;
+    plast   = GenCheck( pnode->turn, amove );
+    
+    for ( pmove = amove; pmove != plast; pmove++ )
+      {
+       int from = I2From(*pmove);
+       int to   = I2To(*pmove);
+       assert( is_move_valid( ptree, *pmove, pnode->turn ) );
+       
+       MakeMove( pnode->turn, *pmove, ply );
+
+       if ( InCheck(pnode->turn) )
+         {
+           UnMakeMove( pnode->turn, *pmove, ply );
+           continue;
+         }
+
+       if ( pnode->new_expansion
+            && ! ( pnode->turn ? b_have_evasion(ptree)
+                                : w_have_evasion(ptree) ) )
+         {
+           pnode->children[0].move  = *pmove;
+           pnode->children[0].phi   = INF;
+           pnode->children[0].delta = 0;
+           pnode->icurr_c           = 0;
+           pnode->nmove             = 1;
+           pnode->children[0].min_hand_b
+             = pnode->turn ? dfpn_max_hand_b( HAND_B, HAND_W )
+                            : dfpn_max_hand_w( HAND_B, HAND_W );
+           
+           UnMakeMove( pnode->turn, *pmove, ply );
+           return 1;
+         }
+
+
+       if ( from < nsquare )
+         {
+           pnode->children[n].is_weak  = 0;
+           pnode->children[n].priority = 1U;
+         }
+       /* drop to next square of the king */
+       else if ( From2Drop(from) == knight
+                 || BBContract( abb_king_attacks[sq_king], abb_mask[to] ) )
+         {
+           pnode->children[n].is_weak  = 0;
+           pnode->children[n].priority = 1U;
+         }
+       /* check by piece drop from far way */
+       else {
+         pnode->children[n].is_weak
+           = weak_drop + ( adirec[sq_king][to] << 1 ) + ( sq_king < to );
+         pnode->children[n].priority = 1U;
+       }
+
+       pnode->children[n].nodes         = 0;
+       pnode->children[n].phi           = 1U;
+       pnode->children[n].delta         = 1U;
+       pnode->children[n].is_loop       = 0;
+       pnode->children[n].is_phi_loop   = 0;
+       pnode->children[n].is_delta_loop = 0;
+       pnode->children[n].hash_key      = HASH_KEY;
+       pnode->children[n].hand_b        = HAND_B;
+       pnode->children[n].min_hand_b    = HAND_B;
+       pnode->children[n].move          = *pmove;
+       pnode->children[n].expanded      = UINT64_MAX;
+       switch( dfpn_detect_rep( pdfpn_tree, HASH_KEY, HAND_B, ply-3, &ip ) )
+         {
+         case 1:
+           DOut( ply, "LOOP DELTA: %s", str_CSA_move(*pmove) );
+           pnode->children[n].is_loop       = 1;
+           pnode->children[n].is_delta_loop = 1;
+           pnode->children[n].delta = pdfpn_tree->anode[ip].delta;
+           assert( pnode->phi <= pdfpn_tree->anode[ip].delta );
+           break;
+
+         default:
+           dfpn_hash_probe( pdfpn_tree, &pnode->children[n], ply,
+                            Flip(pnode->turn) );
+         }
+
+       UnMakeMove( pnode->turn, *pmove, ply );
+       n += 1;
+      }
+
+  } else {
+    
+    bitboard_t bb_intercept;
+    unsigned int to;
+
+    assert( InCheck(pnode->turn) );
+    plast = GenEvasion( pnode->turn, amove );
+    BBIni( bb_intercept );
+
+    sq_king = pnode->turn ? SQ_WKING : SQ_BKING;
+    
+    for ( pmove  = amove; pmove != plast; pmove++ )
+      {
+       assert( is_move_valid( ptree, *pmove, pnode->turn ) );
+       
+       MakeMove( pnode->turn, *pmove, ply );
+
+       pnode->children[n].is_weak = 0;
+       to                         = I2To(*pmove);
+
+       /* capture or king move */
+       if ( I2PieceMove(*pmove) == king || UToCap(*pmove) )
+         {
+           if ( I2PieceMove(*pmove) == king && UToCap(*pmove) )
+             {
+               pnode->children[n].priority = 2U;
+             }
+           else if ( UToCap(*pmove) )
+             {
+               pnode->children[n].priority = 3U;
+             }
+           else { pnode->children[n].priority = 4U; }
+
+           /* non-intercepts may disproof this node easily. */
+           if ( pnode->new_expansion
+                && ! ( pnode->turn ? b_have_checks(ptree)
+                                    : w_have_checks(ptree) ) )
+             {
+               pnode->children[0].move  = *pmove;
+               pnode->children[0].phi   = INF;
+               pnode->children[0].delta = 0;
+               pnode->icurr_c           = 0;
+               pnode->nmove             = 1;
+               pnode->children[0].min_hand_b
+                 = pnode->turn ? dfpn_max_hand_b( HAND_B, HAND_W )
+                                : dfpn_max_hand_w( HAND_B, HAND_W );
+               UnMakeMove( pnode->turn, *pmove, ply );
+               return 1;
+             }
+         }
+
+       /* interseptions by move */
+       else if ( I2From(*pmove) < nsquare )
+         {
+           pnode->children[n].priority = 4U;
+           BBOr( bb_intercept, bb_intercept, abb_mask[to] );
+         }
+       /* interseptions by drop */
+       else if ( BBContract( bb_intercept, abb_mask[to] )
+                 || BBContract( abb_king_attacks[sq_king],
+                                abb_mask[to] ) )
+         {
+           pnode->children[n].priority = 5U;
+           pnode->children[n].is_weak  = weak_drop + to;
+         }
+       /* 'chuai' interseptions */
+       else {
+         pnode->children[n].priority = 6U;
+         pnode->children[n].is_weak  = weak_chuai;
+       }
+
+       pnode->children[n].is_loop       = 0;
+       pnode->children[n].is_phi_loop   = 0;
+       pnode->children[n].is_delta_loop = 0;
+       pnode->children[n].hash_key      = HASH_KEY;
+       pnode->children[n].hand_b        = HAND_B;
+       pnode->children[n].min_hand_b    = HAND_B;
+       pnode->children[n].nodes         = 0;
+       pnode->children[n].phi           = 1U;
+       pnode->children[n].delta         = 1U;
+       pnode->children[n].move          = *pmove;
+       pnode->children[n].expanded      = UINT64_MAX;
+       switch( dfpn_detect_rep( pdfpn_tree, HASH_KEY, HAND_B, ply-3, &ip ) )
+         {
+         case 1:
+           DOut( ply, "LOOP PHI: %s", str_CSA_move(*pmove) );
+           pnode->children[n].is_loop     = 1;
+           pnode->children[n].is_phi_loop = 1;
+           pnode->children[n].phi = pdfpn_tree->anode[ip].phi;
+           assert( pnode->delta <= pdfpn_tree->anode[ip].phi );
+           break;
+
+         default:
+           dfpn_hash_probe( pdfpn_tree, &pnode->children[n], ply,
+                            Flip(pnode->turn) );
+         }
+
+       if ( pnode->children[n].nodes == 0
+            && ! pnode->children[n].is_loop
+            && ! InCheck(Flip(pnode->turn)) ) {
+         unsigned int move = IsMateIn1Ply(Flip(pnode->turn));
+         if ( move ) {
+           
+           unsigned int from       = I2From(move);
+           unsigned int min_hand_b = pnode->turn ? 0 : HAND_B + HAND_W;
+           if ( nsquare <= from ) {
+             unsigned int pc = From2Drop(from);
+             if ( pnode->turn ) { min_hand_b += hand_tbl[pc]; }
+             else               { min_hand_b -= hand_tbl[pc]; }
+           }
+           pnode->children[n].min_hand_b = min_hand_b;
+           pnode->children[n].nodes      = 1;
+           pnode->children[n].phi        = 0;
+           pnode->children[n].delta      = INF;
+         }
+       }
+
+       UnMakeMove( pnode->turn, *pmove, ply );
+       n += 1;
+      }
+  }
+  
+  pnode->nmove = n;
+
+  return 0;
+}
+
+
+/* Select the most promising child */
+static void CONV
+select_child( const tree_t * restrict ptree,
+             node_t * restrict pnode,
+             unsigned int * restrict pphi_c,
+             unsigned int * restrict pdelta_c,
+             unsigned int * restrict pdelta_2 )
+{
+  int n = pnode->nmove;
+  int i, sq_king, dist, drank, dfile, to, dist_c;
+  uint64_t nodes, nodes_c;
+  unsigned int phi, delta, priori, priori_c;
+
+  *pdelta_c = INF;
+  *pdelta_2 = INF;
+  *pphi_c   = INF;
+  priori_c  = UINT_MAX;
+  nodes_c   = UINT64_MAX;
+
+  for ( i = 0; i < n; i++ )
+    {
+      if ( pnode->children[i].is_weak == weak_chuai) { continue; }
+
+      phi    = pnode->children[i].phi;
+      delta  = pnode->children[i].delta;
+      nodes  = pnode->children[i].nodes;
+      priori = pnode->children[i].priority;
+      assert( phi <= INF && delta <= INF );
+
+      /* Store the smallest and second smallest delta in delta_c and delta_2 */
+      if ( delta < *pdelta_c
+          || ( delta == *pdelta_c && nodes < nodes_c )
+          || ( delta == *pdelta_c && nodes == nodes_c && phi < *pphi_c )
+          || ( delta == *pdelta_c && nodes == nodes_c && phi == *pphi_c
+               && priori < priori_c ) )
+       {
+         pnode->icurr_c = i;
+
+         *pdelta_2 = *pdelta_c;
+         *pphi_c   = phi;
+         *pdelta_c = delta;
+         priori_c  = priori;
+         nodes_c   = nodes;
+       }
+      else if ( delta < *pdelta_2 ) { *pdelta_2 = delta; }
+      
+      assert( phi != INF );
+    }
+
+
+  if ( *pdelta_c < INF_1 ) { return; }
+
+
+  /* expand chuai moves, or current node loses */
+  dist_c  = INT_MAX;
+  sq_king = pnode->turn ? SQ_WKING : SQ_BKING;
+  for ( i = 0; i < n; i++ )
+    {
+      if ( pnode->children[i].is_weak != weak_chuai ) { continue; }
+
+      to       = I2To(pnode->children[i].move);
+      drank    = abs( (int)airank[to] - (int)airank[sq_king] );
+      dfile    = abs( (int)aifile[to] - (int)aifile[sq_king] );
+      dist     = drank < dfile ? dfile : drank;
+      phi      = pnode->children[i].phi;
+      delta    = pnode->children[i].delta;
+      assert( phi <= INF && delta <= INF );
+
+      if ( pnode->phi <= delta ) { continue; }
+
+      if ( dist_c == INT_MAX || dist < dist_c )
+       {
+         pnode->icurr_c = i;
+         *pphi_c        = phi;
+         *pdelta_c      = delta;
+         dist_c         = dist;
+       }
+      
+      assert( phi != INF );
+    }
+  
+  *pdelta_2 = INF;
+  pnode->children[pnode->icurr_c].is_weak = 0;
+}
+
+
+static unsigned int CONV
+min_delta_c( const node_t * restrict pnode )
+{
+  int n            = pnode->nmove;
+  unsigned int min = UINT_MAX;
+  int i;
+
+  for ( i = 0; i < n; i++ )
+    {
+      if ( pnode->children[i].is_weak == weak_chuai ) { continue; }
+      if ( pnode->children[i].delta < min ) { min = pnode->children[i].delta; }
+    }
+  if ( min < INF_1 ) { return min; }
+  
+  for ( i = 0; i < n; i++ )
+    {
+      if ( pnode->children[i].is_weak != weak_chuai ) { continue; }
+      if ( pnode->children[i].delta < min ) { min = pnode->children[i].delta; }
+    }
+
+  assert( min <= INF ); 
+  return min;
+}
+
+
+static unsigned int CONV
+sum_phi_c( const node_t * restrict pnode )
+{
+  int n            = pnode->nmove;
+  unsigned int sum = 0;
+  unsigned int value, type, value_chuai;
+  int i, j, have_inf_1, ntype;
+  struct { unsigned int value, type; } aphi[ MAX_NMOVE+1 ];
+
+  ntype       = 0;
+  have_inf_1  = 0;
+  value_chuai = 0;
+  sum         = 0;
+  for ( i = 0; i < n; i++ )
+    {
+      type  = pnode->children[i].is_weak;
+      value = pnode->children[i].phi;
+
+      if ( value == INF ) { return INF; }
+
+      if ( value == INF_1 ) { have_inf_1 = 1; }
+
+      if ( have_inf_1 ) { continue; }
+      if ( value == 0 ) { continue; }
+
+      if ( type == weak_chuai )
+       {
+         if ( value_chuai < value ) { value_chuai = value; }
+         continue;
+       }
+      
+      if ( type == 0 || value != 1 )
+       {
+         sum += value;
+         continue;
+       }
+
+      /* find type in aphi[j].type */
+      for ( j = 0, aphi[ntype].type = type; aphi[j].type != type; j++ );
+
+      
+      if ( j == ntype )  /* not found */
+       {
+         aphi[j].value  = value;
+         ntype         += 1;
+       }
+      else if ( aphi[j].value < value ) { aphi[j].value = value; }
+    }
+
+
+  if ( have_inf_1 ) { return INF_1; }
+
+  for ( i = ntype-1; i >= 0; i-- ) { sum += aphi[i].value; }
+
+  if      ( INF_1 <= sum ) { sum = UINT_MAX; }
+  else if ( sum == 0 )     { sum = value_chuai; }
+
+  return sum;
+}
+
+
+#  if defined(DFPN_DBG)
+static void CONV dbg_nodes( const node_t * restrict pnode, int ply )
+{
+  char buf[65536];
+  int n = pnode->nmove;
+  int i;
+
+  buf[0] = '\0';
+  for ( i = 0; i < n; i++ )
+    {
+      snprintf( buf, 65536, "%s %" PRIu64 "%c ", buf, pnode->children[i].nodes,
+               pnode->children[i].expanded != 0 ? 'o' : 'x' );
+    }
+  DOut( ply, "NODES:%s", buf );
+}
+
+
+static void CONV dbg_min_delta_c( const node_t * restrict pnode, int ply )
+{
+  unsigned int value;
+  char buf[65536];
+  int n = pnode->nmove;
+  int i;
+
+  buf[0] = '\0';
+  for ( i = 0; i < n; i++ )
+    {
+      value = pnode->children[i].delta;
+      if      ( value == INF )   { snprintf( buf, 65536, "%s inf", buf ); }
+      else if ( value == INF_1 ) { snprintf( buf, 65536, "%s inf-1", buf ); }
+      else {
+       snprintf( buf, 65536, "%s %u%s", buf, value,
+                 pnode->children[i].is_delta_loop ? "l" : "" );
+      }
+    }
+  DOut( ply, "DELTA_C=%u:%s", pnode->min_delta, buf );
+}
+
+
+static void CONV dbg_sum_phi_c( const node_t * restrict pnode, int ply )
+{
+  int n = pnode->nmove;
+  unsigned int value, type, value_chuai;
+  int i, j, have_inf_1, ntype, iinf_1;
+  struct {
+    unsigned int value, type, move;
+    int is_loop;
+  } aphi[ MAX_NMOVE+1 ];
+
+  ntype       = 0;
+  have_inf_1  = 0;
+  value_chuai = 0;
+  iinf_1      = 0;
+  for ( i = 0; i < n; i++ )
+    {
+      type  = pnode->children[i].is_weak;
+      value = pnode->children[i].phi;
+
+      if ( value == INF )
+       {
+         DOut( ply, "PHI_C=inf: %s",
+                str_CSA_move(pnode->children[i].move) );
+         return;
+       }
+
+      if ( value == INF_1 ) { have_inf_1 = 1;  iinf_1 = i; }
+
+      if ( have_inf_1 ) { continue; }
+
+      if ( type == weak_chuai )
+       {
+         if ( value_chuai < value ) { value_chuai = value; }
+         continue;
+       }
+      if ( type == 0 || value != 1 ) { type  = UINT_MAX - i; }
+
+      /* find type in aphi[j].type */
+      for ( j = 0, aphi[ntype].type = type; type != aphi[j].type; j++ );
+
+      
+      if ( j == ntype )  /* not found */
+       {
+         aphi[j].value   = value;
+         aphi[j].move    = pnode->children[i].move;
+         aphi[j].is_loop = pnode->children[i].is_phi_loop;
+         ntype          += 1;
+       }
+      else if ( aphi[j].value < value )
+       {
+         aphi[j].value    = value;
+         aphi[j].move     = pnode->children[i].move;
+         aphi[j].is_loop &= pnode->children[i].is_phi_loop;
+       }
+    }
+
+  if ( have_inf_1 )
+    {
+      DOut( ply, "PHI_C=inf-1: %s",
+           str_CSA_move(pnode->children[iinf_1].move) );
+    }
+  else {
+    char buf[65536];
+
+    buf[0] = '\0';
+    for ( i = 0; i < ntype; i++ )
+      {
+       snprintf ( buf, 65536, "%s %s(%u%s)", buf,
+                  str_CSA_move(aphi[i].move), aphi[i].value,
+                  aphi[i].is_loop ? "l" : "" );
+      }
+    
+    if ( value_chuai )
+      {
+       snprintf( buf, 65536, "%s CHUAI(%u)", buf, value_chuai );
+      }
+    DOut( ply, "PHI_C=%u:%s", pnode->sum_phi, buf );
+  }
+}
+
+
+static void CONV
+dbg_out_move_seq( const node_t * restrict nodes, int ply )
+{
+  char buf[65536];
+  int i;
+
+  buf[0] = '\0';
+  for ( i = 1; i < ply; i++ )
+    {
+      unsigned int move = nodes[i].children[nodes[i].icurr_c].move;
+      snprintf( buf, 65536, "%s %s", buf, str_CSA_move(move) );
+    }
+  DOut( ply, "HIST:%s", buf );
+}
+
+#  endif
+
+#endif /* DFPN */