Ticket #172: read-trymoves.patch

engine/reading.c

@@ -131 +131 @@
  * is a defense version.
  */
 #define DEFEND_TRY_MOVES(no_deep_branching, attack_hint)                \
+  DEFEND_TRY_MOVES_LIMIT(no_deep_branching, attack_hint, WIN)
+
+/* Like DEFEND_TRY_MOVES but called when the best possible result is
+ * known - we can finish trying moves earlier.
+ */
+#define DEFEND_TRY_MOVES_LIMIT(no_deep_branching, attack_hint, limit)   \
   do {                                                                  \
     int k;                                                              \
                                                                         \
@@ -139 +145 @@
       int dpos = moves.pos[k];                                          \
                                                                         \
       if (komaster_trymove(dpos, color, moves.message[k], str, &ko_move,\
-                           stackp <= ko_depth && savecode == 0)) {      \
+                           stackp <= ko_depth && !savecode)) {          \
         int acode = do_attack(str, (attack_hint));                      \
         popgo();                                                        \
                                                                         \
@@ -153 +159 @@
             savecode = KO_B;                                            \
           }                                                             \
         }                                                               \
-      }                                                                 \
                                                                         \
-      if ((no_deep_branching) && stackp >= branch_depth)                \
-        RETURN_RESULT(savecode, savemove, move, "branching limit");     \
+        if (savecode == (limit))                                        \
+          RETURN_RESULT(savecode, savemove, move, "best defense");      \
+                                                                        \
+        if ((no_deep_branching) && stackp >= branch_depth)              \
+          RETURN_RESULT(savecode, savemove, move, "branching limit");   \
+      }                                                                 \
     }                                                                   \
                                                                         \
     moves.num_tried = moves.num;                                        \
@@ -177 +186 @@
                                                                         \
       if ((board_ko_pos || !send_two_return_one(apos, other))           \
           && komaster_trymove(apos, other,moves.message[k],str,&ko_move,\
-                              stackp <= ko_depth && savecode == 0)) {   \
+                              stackp <= ko_depth && !savecode)) {       \
         int dcode = do_find_defense(str, (defense_hint));               \
                                                                         \
         if (REVERSE_RESULT(dcode) > savecode                            \
             && do_attack(str, NULL)) {  \
           if (!ko_move) {                                               \
-            if (dcode == 0) {                                           \
+            if (!dcode) {                                               \
               popgo();                                                  \
               RETURN_RESULT(WIN, apos, move, "attack effective");       \
             }                                                           \
@@ -198 +207 @@
         }                                                               \
                                                                         \
         popgo();                                                        \
-      }                                                                 \
                                                                         \
-      if ((no_deep_branching) && stackp >= branch_depth)                \
-        RETURN_RESULT(savecode, savemove, move, "branching limit");     \
+        if ((no_deep_branching) && stackp >= branch_depth)              \
+          RETURN_RESULT(savecode, savemove, move, "branching limit");   \
+      }                                                                 \
     }                                                                   \
                                                                         \
     moves.num_tried = moves.num;                                        \
@@ -1420 +1429 @@
   int savecode = 0;
   int liberties;
   int k;
+  int suggest_move;
 
   SETUP_TRACE_INFO("defend1", str);
   reading_node_counter++;
@@ -1444 +1454 @@
   moves.message[0] = "liberty";
   moves.num = 1;
   moves.num_tried = 0;
+  suggest_move = NO_MOVE;
 
   break_chain_moves(str, &moves);
   set_up_snapback_moves(str, lib, &moves);
 
   order_moves(str, &moves, color, READ_FUNCTION_NAME, *move);
-  DEFEND_TRY_MOVES(0, NULL);
+  DEFEND_TRY_MOVES(0, &suggest_move);
 
   /* If the string is a single stone and a capture would give a ko,
    * try to defend it with ko by backfilling or killing neighbors
@@ -1483 +1494 @@
      * (see trevord:700 for example, when these moves could be
      * helpful). */
     if (!savecode && stackp <= break_chain_depth) {
-      int k;
-
       /* Find neighbors of group created by filling a ko, which
        * have up to two liberties and aren't neighbors of a ko
        * stone.
@@ -1497 +1506 @@
       popgo();
 
       order_moves(str, &moves, color, READ_FUNCTION_NAME, *move);
-
-      for (k = moves.num_tried; k < moves.num; k++) {
-        int dpos = moves.pos[k];
-        if (komaster_trymove(dpos, color, moves.message[k], str,
-                             &ko_move, stackp <= ko_depth)) {
-          int acode = do_attack(str, NULL);
-          popgo();
-          CHECK_RESULT(savecode, savemove, acode, dpos, move,
-                       "defense effective");
-
-          if (savecode)
-            break;
-        }
-      }
+      DEFEND_TRY_MOVES_LIMIT(0, &suggest_move, KO_B);
     }
   }