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[gnugo-devel] arend_3_9.1: reading patch
|
From: |
Arend Bayer |
|
Subject: |
[gnugo-devel] arend_3_9.1: reading patch |
|
Date: |
Sun, 8 Sep 2002 14:10:30 +0200 (CEST) |
This patch might require a little discussion.
At the moment, we have no less than 52 recursive calls to do_attack() in
reading.c (and 23 to do_find_defense), i.e. more than 50 trymove
loops in the standard reading code.
[This is partly because of the defend{1,2,3,4} etc. split, partly due to
them being split up in a couple of trymove loops, and due to the helper
functions such as special_resuce() and friends having their own trymove()
loops (instead of adding their proposed moves to the move list tried in
defend*).]
This has obvious disadvantages -- the code is extremely lengthy, it's
pretty tedious to make conceptual changes (e.g. adding a killer move
heuristic would currently be quite a big patch), and the "special moves"
proposed by the helper functions cannot benefit from the (according to
my impressions) very well-tuned move valuations in order_moves().
This patch starts addressing this, taking the functions
special_rescue(), special_rescue2() and break_chain2() as examples. They
are converted to .._moves functions. Also, two trymove() loops in defend2
resp. defend3 are integrated into a single one.
This shows a couple of subtleties.
* break_chain2() did some kind of forward pruning that would be a pain to
do with these revisions. Hence I simply killed that.
* It took a little effort to re-tune the move ordering; not so much for the
number of reading nodes; but often it is also relevant _which_ defense
move return (see global:31 below for a typical example).
(Relevant for that: where I added the calls to the new .._moves functions
in defend?; also see the devalueing of moves in break_chain2_defense_moves)
The overall result is mixed. The reading nodes for reading.tst dropped
spectacularly by almost 20% (didn't check where this came from); for
nngs.tst (more relevant of course) the decrease was ~1%.
For regression changes see below.
There is another obvious problem, namely generating those moves also
takes time. And with more such changes we will more generate more such
moves that will not get used.
However, I still think it is the right thing to do. Probably it is
best to proceed by converting all the other helper functions into
.._moves functions, too. Maybe it is best to keep doing this in small
steps, to make sure we don't hurt the move ordering.
Once this is done, one could also think about moving the trymove() loops
from defend?() to do_find_defense(); then defend?() would be called to the
generate the move list that should be tried -- maybe split up in two
separate batches to decrease the run-time cost in the frequent cases
where the obvious moves are sufficient.
Gunnar suggested having only one trymove() loop for attack/defense, resp.,
a while ago. I guess this is how we could get there.
Arend
- functions special_rescue(), special_rescue2() converted to .._moves()
- break_chain2() removed; use new function break_chain2_defense_moves()
instead
- defend2() and defend3() simplified
6 PASSes and 6 FAILs.
The changes in nicklas3:401 and global:31
(GNU Go now thinks that the white group at D9 is owl attackable; this is
due to moving the save_lunch defense point for C7 after white plays at C8
from A6 to B8. An improvement I think.)
seem fine to me.
nngs:500 and 510 are due to an persistent cache effect, I didn't quite
get to analyze those (seems the semeai on the right is always being
misanalyzed; we should make a reading test case out of that one).
./regress.sh . nngs1.tst
30 unexpected PASS!
./regress.sh . trevorb.tst
380 unexpected FAIL: Correct 'K4', got 'L5'
./regress.sh . nicklas2.tst
701 unexpected PASS!
./regress.sh . nicklas3.tst
401 unexpected FAIL: Correct 'A5', got 'C6'
./regress.sh . trevor.tst
262 unexpected PASS!
./regress.sh . nngs.tst
500 unexpected FAIL: Correct 'J17', got 'Q1'
510 unexpected FAIL: Correct 'G14', got 'Q1'
600 unexpected PASS!
./regress.sh . strategy3.tst
122 unexpected PASS!
./regress.sh . global.tst
31 unexpected FAIL: Correct 'M8', got 'F11'
38 unexpected PASS!
./regress.sh . auto_handtalk.tst
7 unexpected FAIL: Correct 'ALIVE DEAD (O18|O17|P17)', got 'DEAD ALIVE PASS'
Index: engine/reading.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/reading.c,v
retrieving revision 1.67
diff -u -r1.67 reading.c
--- engine/reading.c 23 Aug 2002 06:56:48 -0000 1.67
+++ engine/reading.c 8 Sep 2002 11:01:50 -0000
@@ -140,12 +140,10 @@
static int defend2(int str, int *move, int komaster, int kom_pos);
static int defend3(int str, int *move, int komaster, int kom_pos);
static int defend4(int str, int *move, int komaster, int kom_pos);
-static int special_rescue(int str, int lib, int *move,
- int komaster, int kom_pos,
- int tried[], int num_tried);
-static int special_rescue2(int str, int libs[2], int *move,
- int komaster, int kom_pos,
- int tried[], int num_tried);
+static void special_rescue_moves(int str, int lib,
+ struct reading_moves *moves);
+static void special_rescue2_moves(int str, int libs[2],
+ struct reading_moves *moves);
static int special_rescue3(int str, int libs[3], int *move,
int komaster, int kom_pos);
static int special_rescue4(int str, int libs[3], int *move,
@@ -180,7 +178,7 @@
struct reading_moves *moves);
static void break_chain2_moves(int str, struct reading_moves *moves,
int require_safe);
-static int break_chain2(int str, int *move, int komaster, int kom_pos);
+static void break_chain2_defense_moves(int str, struct reading_moves *moves);
static int break_chain3(int str, int *move, int komaster, int kom_pos);
static int superstring_breakchain(int str, int *move,
int komaster, int kom_pos,
@@ -1227,9 +1225,9 @@
int liberties2;
int libs2[6];
struct reading_moves moves;
+ int saved_num_moves;
int savemove = 0;
int savecode = 0;
- int bc;
int k;
int r;
int s;
@@ -1264,6 +1262,14 @@
propose_edge_moves(str, libs, liberties, &moves, color);
edge_clamp_moves(str, &moves);
+ if (stackp <= depth) {
+ for (k = 0; k < liberties; k++)
+ special_rescue_moves(str, libs[k], &moves);
+ }
+
+ if (stackp <= backfill_depth)
+ special_rescue2_moves(str, libs, &moves);
+
order_moves(str, &moves, color, read_function_name, 0);
for (k = 0; k < moves.num; k++) {
@@ -1346,31 +1352,17 @@
}
}
- if (stackp <= depth) {
- for (k = 0; k < liberties; k++) {
- int dcode = special_rescue(str, libs[k], &xpos, komaster, kom_pos,
- moves.pos, moves.num);
- CHECK_RESULT_UNREVERSED(savecode, savemove, dcode, xpos, move,
- "special rescue");
- }
- }
-
- if (stackp <= backfill_depth) {
- int dcode = special_rescue2(str, libs, &xpos, komaster, kom_pos,
- moves.pos, moves.num);
- CHECK_RESULT_UNREVERSED(savecode, savemove, dcode, xpos, move,
- "special rescue2");
- }
-
if (level >= 10 && stackp <= superstring_depth) {
int dcode = superstring_breakchain(str, &xpos, komaster, kom_pos, 4);
CHECK_RESULT_UNREVERSED(savecode, savemove, dcode, xpos, move,
"superstring_breakchain");
}
+
/* If nothing else works, we try playing a liberty of the
* super_string.
*/
+ saved_num_moves = moves.num;
if (level >= 10 && stackp <= superstring_depth) {
int ss_liberties;
int ss_libs[MAX_LIBERTIES + 4];
@@ -1379,28 +1371,11 @@
for (k = 0; k < ss_liberties; k++) {
int apos = ss_libs[k];
- /* Skip if already tried */
- for (s = 0; s < moves.num; s++)
- if (apos == moves.pos[s])
- break;
- if (s < moves.num)
- continue;
-
if (liberty_of_string(apos, str))
continue;
- if (trymove(apos, color, "defend2-E", str, komaster, kom_pos)) {
- int acode;
- /* If the newly placed stone is in atari, we give up without fight. */
- if (countlib(apos) == 1)
- acode = WIN;
- else {
- acode = do_attack(str, NULL, komaster, kom_pos);
- moves.pos[s] = apos;
- }
- popgo();
- CHECK_RESULT(savecode, savemove, acode, apos, move,
- "superstring liberty");
- }
+ /* If the newly placed would be in atari, we won't even try. */
+ if (approxlib(apos, color, 2, NULL) > 1)
+ ADD_CANDIDATE_MOVE(apos, 0, moves);
}
/* Now we are truly desperate. Try playing second order liberties of
@@ -1408,64 +1383,55 @@
*/
for (k = 0; k < ss_liberties; k++) {
int apos = ss_libs[k];
- int dcode;
-
+
if (liberty_of_string(apos, str))
continue;
-
- dcode = special_rescue(str, apos, &xpos, komaster, kom_pos,
- moves.pos, moves.num);
- CHECK_RESULT_UNREVERSED(savecode, savemove, dcode, xpos, move,
- "special rescue");
+
+ special_rescue_moves(str, apos, &moves);
}
}
- /* We place the more speculative moves trying to break chain links
- * with 2 or 3 liberties last, because these moves often are not
- * really relevant.
- */
-
- bc = break_chain2(str, &xpos, komaster, kom_pos);
- CHECK_RESULT_UNREVERSED(savecode, savemove, bc, xpos, move,
- "break chain2");
+ break_chain2_defense_moves(str, &moves);
if (stackp <= backfill_depth) {
- int saved_num_moves = moves.num;
special_rescue5_moves(str, libs, &moves);
+ }
- /* Only order and test the new set of moves. */
- order_moves(str, &moves, other, read_function_name, saved_num_moves);
+ /* Only order and test the new set of moves. */
+ order_moves(str, &moves, other, read_function_name, saved_num_moves);
- for (k = saved_num_moves; k < moves.num; k++) {
- int new_komaster;
- int new_kom_pos;
- int ko_move;
- xpos = moves.pos[k];
- if (is_self_atari(xpos, color))
- continue;
-
- if (komaster_trymove(xpos, color, "defend2-F", str,
- komaster, kom_pos, &new_komaster, &new_kom_pos,
- &ko_move, stackp <= ko_depth && savecode == 0)) {
- if (!ko_move) {
- int acode = do_attack(str, NULL, new_komaster, new_kom_pos);
- popgo();
- CHECK_RESULT(savecode, savemove, acode, xpos, move,
- "defense effective - A");
- }
- else {
- if (do_attack(str, NULL, new_komaster, new_kom_pos) != WIN) {
- savemove = xpos;
- savecode = KO_B;
- }
- popgo();
+ for (k = saved_num_moves; k < moves.num; k++) {
+ int new_komaster;
+ int new_kom_pos;
+ int ko_move;
+ xpos = moves.pos[k];
+
+ if (komaster_trymove(xpos, color, "defend2-E", str,
+ komaster, kom_pos, &new_komaster, &new_kom_pos,
+ &ko_move, stackp <= ko_depth && savecode == 0)) {
+ if (!ko_move) {
+ int acode = do_attack(str, NULL, new_komaster, new_kom_pos);
+ popgo();
+ CHECK_RESULT(savecode, savemove, acode, xpos, move,
+ "defense effective - A");
+ }
+ else {
+ if (do_attack(str, NULL, new_komaster, new_kom_pos) != WIN) {
+ savemove = xpos;
+ savecode = KO_B;
}
+ popgo();
}
}
}
+ /* We place the more speculative moves trying to break chain links
+ * with 2 or 3 liberties last, because these moves often are not
+ * really relevant.
+ */
+
if (stackp <= backfill2_depth) {
- bc = break_chain3(str, &xpos, komaster, kom_pos);
+ int bc = break_chain3(str, &xpos, komaster, kom_pos);
CHECK_RESULT_UNREVERSED(savecode, savemove, bc, xpos, move,
"break chain3");
}
@@ -1491,9 +1457,9 @@
int liberties;
int libs[3];
struct reading_moves moves;
+ int saved_num_moves;
int savemove = 0;
int savecode = 0;
- int bc;
int k;
SETUP_TRACE_INFO("defend3", str);
@@ -1620,14 +1586,6 @@
#endif
/* If nothing else works, try to defend with second order liberties. */
- if (stackp <= depth) {
- for (k = 0; k < liberties; k++) {
- int dcode = special_rescue(str, libs[k], &xpos, komaster, kom_pos,
- moves.pos, moves.num);
- CHECK_RESULT_UNREVERSED(savecode, savemove, dcode, xpos, move,
- "special rescue");
- }
- }
if (stackp <= backfill_depth) {
int dcode = special_rescue3(str, libs, &xpos, komaster, kom_pos);
@@ -1647,6 +1605,17 @@
"superstring_breakchain");
}
+
+ saved_num_moves = moves.num;
+
+ if (stackp <= depth) {
+ for (k = 0; k < liberties; k++)
+ special_rescue_moves(str, libs[k], &moves);
+ }
+
+ if (stackp <= backfill2_depth)
+ break_chain2_defense_moves(str, &moves);
+
/* If nothing else works, we try playing a liberty of the
* super_string.
*/
@@ -1660,18 +1629,9 @@
if (liberty_of_string(apos, str))
continue;
- if (trymove(apos, color, "defend3-C", str, komaster, kom_pos)) {
- int acode;
- /* If the newly placed stone is in atari, we give up without fight. */
- if (countlib(apos) == 1)
- acode = WIN;
- else
- acode = do_attack(str, NULL, komaster, kom_pos);
-
- popgo();
- CHECK_RESULT(savecode, savemove, acode, apos, move,
- "superstring liberty");
- }
+ /* If the newly placed would be in atari, we won't even try. */
+ if (approxlib(apos, color, 2, NULL) > 1)
+ ADD_CANDIDATE_MOVE(apos, 0, moves);
}
/* Now we are truly desperate. Try playing second order liberties of
@@ -1679,66 +1639,54 @@
*/
for (k = 0; k < ss_liberties; k++) {
int apos = ss_libs[k];
- int dcode;
if (liberty_of_string(apos, str))
continue;
- dcode = special_rescue(str, apos, &xpos, komaster, kom_pos,
- moves.pos, moves.num);
- CHECK_RESULT_UNREVERSED(savecode, savemove, dcode, xpos, move,
- "special rescue");
+ special_rescue_moves(str, apos, &moves);
}
}
- /* We place the more speculative moves trying to break chain links
- * with 2 or 3 liberties last, because these moves often are not
- * really relevant.
- */
- if (stackp <= backfill2_depth) {
- bc = break_chain2(str, &xpos, komaster, kom_pos);
- CHECK_RESULT_UNREVERSED(savecode, savemove, bc, xpos, move,
- "break chain2");
- }
-
if (stackp <= backfill_depth) {
- int saved_num_moves = moves.num;
special_rescue5_moves(str, libs, &moves);
special_rescue6_moves(str, libs, &moves);
+ }
- /* Only order and test the new set of moves. */
- order_moves(str, &moves, other, read_function_name, saved_num_moves);
+ /* Only order and test the new set of moves. */
+ order_moves(str, &moves, other, read_function_name, saved_num_moves);
+
+ for (k = saved_num_moves; k < moves.num; k++) {
+ int new_komaster;
+ int new_kom_pos;
+ int ko_move;
+ xpos = moves.pos[k];
- for (k = saved_num_moves; k < moves.num; k++) {
- int new_komaster;
- int new_kom_pos;
- int ko_move;
- xpos = moves.pos[k];
- if (is_self_atari(xpos, color))
- continue;
-
- if (komaster_trymove(xpos, color, "defend3-E", str,
- komaster, kom_pos, &new_komaster, &new_kom_pos,
- &ko_move, stackp <= ko_depth && savecode == 0)) {
- if (!ko_move) {
- int acode = do_attack(str, NULL, new_komaster, new_kom_pos);
- popgo();
- CHECK_RESULT(savecode, savemove, acode, xpos, move,
- "defense effective - A");
- }
- else {
- if (do_attack(str, NULL, new_komaster, new_kom_pos) != WIN) {
- savemove = xpos;
- savecode = KO_B;
- }
- popgo();
+ if (komaster_trymove(xpos, color, "defend3-E", str,
+ komaster, kom_pos, &new_komaster, &new_kom_pos,
+ &ko_move, stackp <= ko_depth && savecode == 0)) {
+ if (!ko_move) {
+ int acode = do_attack(str, NULL, new_komaster, new_kom_pos);
+ popgo();
+ CHECK_RESULT(savecode, savemove, acode, xpos, move,
+ "defense effective - A");
+ }
+ else {
+ if (do_attack(str, NULL, new_komaster, new_kom_pos) != WIN) {
+ savemove = xpos;
+ savecode = KO_B;
}
+ popgo();
}
}
}
-
+
+ /* We place the more speculative moves trying to break chain links
+ * with 2 or 3 liberties last, because these moves often are not
+ * really relevant.
+ */
+
if (stackp <= backfill2_depth) {
- bc = break_chain3(str, &xpos, komaster, kom_pos);
+ int bc = break_chain3(str, &xpos, komaster, kom_pos);
CHECK_RESULT_UNREVERSED(savecode, savemove, bc, xpos, move,
"break chain3");
}
@@ -1795,6 +1743,9 @@
break_chain_moves(str, &moves);
break_chain2_efficient_moves(str, &moves);
+ if (stackp <= backfill_depth)
+ break_chain2_defense_moves(str, &moves);
+
order_moves(str, &moves, color, read_function_name, 0);
for (k = 0; k < moves.num; k++) {
@@ -1826,11 +1777,6 @@
}
}
- if (stackp <= backfill_depth) {
- int bc = break_chain2(str, &xpos, komaster, kom_pos);
- CHECK_RESULT_UNREVERSED(savecode, savemove, bc, xpos, move,
- "break chain2");
- }
if (savecode != 0)
RETURN_RESULT(savecode, savemove, move, "saved move");
@@ -1841,12 +1787,11 @@
/*
- * special_rescue(str, lib, *move) is called with (str) a
- * string having a liberty at (lib). The saving move is returned
- * in (*move).
+ * special_rescue_moves(str, lib, *move) is called with (str) a
+ * string having a liberty at (lib).
*
- * This checks whether a move on a second order liberty is a rescuing
- * move, e.g. in shapes like:
+ * This adds moves on a second order liberty to the list of candidate
+ * moves in the struct *moves; e.g. in shapes like:
*
* . O O X.XXO
* O.* or ..* or O.* or XOOXO
@@ -1859,25 +1804,17 @@
* corresponding first order liberty.
*/
-static int
-special_rescue(int str, int lib, int *move, int komaster, int kom_pos,
- int tried[], int num_tried)
+static void
+special_rescue_moves(int str, int lib, struct reading_moves *moves)
{
int color = board[str];
int other = OTHER_COLOR(color);
- int k, r;
- int savemove = 0;
- int savecode = 0;
+ int k;
/* Loop over the four neighbours of the liberty, (lib + d). */
for (k = 0; k < 4; k++) {
int d = delta[k];
if (board[lib + d] == EMPTY) {
- for (r = 0; r < num_tried; r++)
- if (lib + d == tried[r])
- break;
- if (r < num_tried)
- continue;
/* Use approxlib() to test for trivial capture. */
if (approxlib(lib, other, 3, NULL) > 2)
@@ -1887,22 +1824,9 @@
if (is_self_atari(lib + d, color))
continue;
- if (trymove(lib + d, color, "special_rescue", str, komaster, kom_pos)) {
- int acode = do_attack(str, NULL, komaster, kom_pos);
- popgo();
- if (acode == 0) {
- *move = lib + d;
- return WIN;
- }
- UPDATE_SAVED_KO_RESULT(savecode, savemove, acode, lib + d);
- }
+ ADD_CANDIDATE_MOVE(lib + d, 0, *moves);
}
}
-
- if (savecode != 0)
- *move = savemove;
-
- return savecode;
}
@@ -1920,23 +1844,16 @@
* ...OOX
* ------
*/
-static int
-special_rescue2(int str, int libs[2], int *move, int komaster, int kom_pos,
- int tried[], int num_tried)
+static void
+special_rescue2_moves(int str, int libs[2], struct reading_moves *moves)
{
int color = board[str];
int other = OTHER_COLOR(color);
int newlibs[4];
int liberties;
int newstr;
- int xpos;
- struct reading_moves moves;
- int savemove = 0;
- int savecode = 0;
int k, r, s;
- moves.num = 0;
-
for (r = 0; r < 2; r++) {
/* Let alib be one of the liberties and require it to be suicide
* for the opponent.
@@ -1952,42 +1869,15 @@
liberties = findlib(newstr, 4, newlibs);
for (s = 0; s < liberties && s < 4; s++) {
- ADD_CANDIDATE_MOVE(newlibs[s], 0, moves);
+ if (!is_self_atari(newlibs[s], color))
+ ADD_CANDIDATE_MOVE(newlibs[s], 0, *moves);
}
- break_chain_moves(newstr, &moves);
- break_chain2_efficient_moves(newstr, &moves);
- edge_clamp_moves(newstr, &moves);
+ break_chain_moves(newstr, moves);
+ break_chain2_efficient_moves(newstr, moves);
+ edge_clamp_moves(newstr, moves);
}
}
}
-
- for (k = 0; k < moves.num; k++) {
- xpos = moves.pos[k];
- for (r = 0; r < num_tried; r++)
- if (xpos == tried[r])
- break;
- if (r < num_tried)
- continue;
-
- if (!is_self_atari(xpos, color)
- && trymove(xpos, color, "special_rescue2", str, komaster, kom_pos)) {
- int acode = do_attack(str, NULL, komaster, kom_pos);
- if (acode != WIN) {
- if (acode == 0) {
- popgo();
- *move = xpos;
- return WIN;
- }
- UPDATE_SAVED_KO_RESULT(savecode, savemove, acode, xpos);
- }
- popgo();
- }
- }
-
- if (savecode != 0)
- *move = savemove;
-
- return savecode;
}
@@ -2218,7 +2108,8 @@
liberties2 = findlib(bpos, 4, libs2);
for (s = 0; s < liberties2; s++)
- if (!liberty_of_string(libs2[s], str))
+ if (!liberty_of_string(libs2[s], str)
+ && !is_self_atari(libs2[s], color))
ADD_CANDIDATE_MOVE(libs2[s], 0, *moves);
/* Reinforce the second order chain. */
@@ -2232,7 +2123,8 @@
break_chain_moves(adjs[t], moves);
findlib(adjs[t], 1, &cpos);
- ADD_CANDIDATE_MOVE(cpos, 0, *moves);
+ if (!is_self_atari(cpos, color))
+ ADD_CANDIDATE_MOVE(cpos, 0, *moves);
}
/* Defend against double atari in the surrounding chain early. */
@@ -2311,8 +2203,10 @@
continue;
- ADD_CANDIDATE_MOVE(cpos + right, 0, *moves);
- ADD_CANDIDATE_MOVE(cpos + up, 0, *moves);
+ if (!is_self_atari(cpos + right, color))
+ ADD_CANDIDATE_MOVE(cpos + right, 0, *moves);
+ if (!is_self_atari(cpos + up, color))
+ ADD_CANDIDATE_MOVE(cpos + up, 0, *moves);
}
}
}
@@ -4617,9 +4511,18 @@
}
}
+/*
+ * (str) points to a group with two liberties. break_chain2_moves
+ * tries to defend this worm by attacking * a neighbouring worm with
+ * two liberties.
+ * This is done by playing on either of its liberties
+ * (if (require_safe) is true these are only used if they are not
+ * self-ataris), taking a neighbour out of atari or by backfilling if
+ * both liberties are self-ataris.
+ */
+
static void
-break_chain2_moves(int str, struct reading_moves *moves,
- int require_safe)
+break_chain2_moves(int str, struct reading_moves *moves, int require_safe)
{
int color = board[str];
int other = OTHER_COLOR(color);
@@ -4677,147 +4580,25 @@
}
/*
- * (str) points to a group. break_chain2(str, &move)
- * returns WIN if there is a string in the surrounding chain having
- * exactly two liberties whose attack leads to the rescue of
- * (str). Then (*move) points to the location of the attacking move.
- *
- * Returns KO_A if the saving move depends on ignoring a ko threat;
- *
- * Returns KO_B if the saving move requires making a ko threat and winning
- * the ko.
+ * (str) points to a group to be defended.
+ * break_chain2_defense_moves is a wrapper around break_chain2_moves.
+ * It devalues all entries by 2.
+ *
+ * Rationale: Otherwise, these moves get overvalued by order_moves. In
+ * particular, if there is both a direct and a break_chain2 defense,
+ * then the latter one might be just an irrelevant intermediate forcing
+ * move. Hence, we should rather return the direct defense.
*/
-static int
-break_chain2(int str, int *move, int komaster, int kom_pos)
+static void
+break_chain2_defense_moves(int str, struct reading_moves *moves)
{
- int color = board[str];
- int other = OTHER_COLOR(color);
- int v;
- int libs[2];
- int liberties;
- struct reading_moves moves;
- int savemove = 0;
- int savecode = 0;
-
- SETUP_TRACE_INFO("break_chain2", str);
- moves.num = 0;
-
- RTRACE("in break_chain2 at %1m\n", str);
-
- break_chain2_moves(str, &moves, 0);
- order_moves(str, &moves, color, read_function_name, 0);
-
- /* We do not wish to consider the move if it can be
- * immediately recaptured, unless stackp <= backfill_depth.
- *
- * With the incremental board code it's not much point in using
- * approxlib() as heuristic whether we want to play the move. Better
- * and more accurate to really play the move and then use findlib() to
- * see how many liberties we obtained.
- */
-
- for (v = 0; v < moves.num; v++) {
- int new_komaster;
- int new_kom_pos;
- int ko_move;
-
- if (komaster_trymove(moves.pos[v], color, "break_chain2-A", str,
- komaster, kom_pos, &new_komaster, &new_kom_pos,
- &ko_move, savecode == 0 && stackp <= ko_depth)) {
- if (ko_move) {
- if (do_attack(str, NULL, new_komaster, new_kom_pos) != WIN) {
- savecode = KO_B;
- savemove = moves.pos[v];
- }
- popgo();
- continue;
- }
- }
- else
- continue;
-
- /* If we reach here, we have made a move, which was not a
- * conditional ko capture.
- */
- liberties = findlib(moves.pos[v], 2, libs);
- if (liberties > 1) {
- int acode = do_attack(str, NULL, new_komaster, new_kom_pos);
- if (acode == 0) {
- *move = moves.pos[v];
- popgo();
- SGFTRACE(moves.pos[v], 1, "attack defended-A");
- return WIN;
- }
- UPDATE_SAVED_KO_RESULT(savecode, savemove, acode, moves.pos[v]);
- }
- else if (stackp <= backfill_depth) {
- int newer_komaster;
- int newer_kom_pos;
- int bpos = libs[0];
- int try_harder = 0;
-
- ASSERT1(liberties == 1, str);
-
- if (komaster_trymove(bpos, other, "break_chain2-C", str,
- new_komaster, new_kom_pos,
- &newer_komaster, &newer_kom_pos,
- &ko_move, savecode == 0 && stackp <= ko_depth)) {
- if (!ko_move) {
- if (countlib(bpos) <= 2)
- try_harder = 1;
- if (IS_STONE(board[str])) {
- int dcode = do_find_defense(str, NULL, newer_komaster,
- newer_kom_pos);
- if (dcode == WIN && !try_harder) {
- *move = moves.pos[v];
- popgo();
- popgo();
- SGFTRACE(moves.pos[v], WIN, "attack defended-B");
- return WIN;
- }
- /* FIXME: Possibly the ko result codes are not handled
- * correctly in the presence of two trymove().
- */
- UPDATE_SAVED_KO_RESULT_UNREVERSED(savecode, savemove,
- dcode, moves.pos[v]);
- }
- popgo();
- }
- else {
- try_harder = 1;
- ASSERT1(IS_STONE(board[str]), str);
- if (do_find_defense(str, NULL, newer_komaster, newer_kom_pos) != 0) {
- savecode = KO_A; /* Not KO_B since we are one move deeper
- * than usual. */
- savemove = moves.pos[v];
- }
- popgo();
- }
- }
-
- if (try_harder) {
- int acode = do_attack(str, NULL, new_komaster, new_kom_pos);
- if (acode == 0) {
- *move = moves.pos[v];
- popgo();
- SGFTRACE(moves.pos[v], WIN, "attack defended-C");
- return WIN;
- }
- UPDATE_SAVED_KO_RESULT(savecode, savemove, acode, moves.pos[v]);
- }
- }
- popgo(); /* (moves.pos[v]) */
- }
-
- if (savecode != 0) {
- *move = savemove;
- SGFTRACE(savemove, savecode, "saved move");
- return savecode;
- }
+ int saved_num_moves = moves->num;
+ int k;
- SGFTRACE(0, 0, NULL);
- return 0;
+ break_chain2_moves(str, moves, !(stackp <= backfill_depth));
+ for (k = saved_num_moves; k < moves->num; k++)
+ moves->score[k] = -2;
}
- [gnugo-devel] arend_3_9.1: reading patch,
Arend Bayer <=