SEE pruning in qsearch

Bench: 2525875
SzilBalazs · Jul 18, 2023 · 6b1dd10 · 6b1dd10
1 parent e898c8f
commit 6b1dd10
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Showing 3 changed files with 4 additions and 1 deletion.
diff --git a/src/search/move_list.h b/src/search/move_list.h
@@ -19,6 +19,7 @@
 
 #include "../core/movegen.h"
 #include "history.h"
+#include "see.h"
 
 namespace search {
     template<bool captures_only>

diff --git a/src/search/search_thread.h b/src/search/search_thread.h
@@ -360,6 +360,8 @@ namespace search {
             while (!move_list.empty()) {
                 core::Move move = move_list.next_move();
 
+                if (alpha > -WORST_MATE && !see(board, move, 0)) continue;
+
                 shared.node_count++;
                 board.make_move(move, &nnue);
                 Score score = -qsearch<node_type>(-beta, -alpha);

diff --git a/src/search/see.h b/src/search/see.h
@@ -61,7 +61,7 @@ namespace search {
             stm = color_enemy(stm);
 
             if (value >= 0) {
-                if (type == KING && (attackers & board.pieces(stm))) {
+                if (type == KING && (attackers & board.sides(stm))) {
                     stm = color_enemy(stm);
                 }
                 break;