Do not probe syzygy bases when castling is possible

Joona Kiiski · zamar · commit 8c3a5bbc5284 · 2016-01-20T15:24:21.000Z
Almost no functional change. Bench is unchanged. Resolves #230 Resolves #573
diff --git a/src/search.cpp b/src/search.cpp
@@ -256,8 +256,9 @@ void MainThread::search() {
   }
   else
   {
-      if (TB::Cardinality >=  rootPos.count<ALL_PIECES>(WHITE)
-                            + rootPos.count<ALL_PIECES>(BLACK))
+      if (    TB::Cardinality >=  rootPos.count<ALL_PIECES>(WHITE)
+                                + rootPos.count<ALL_PIECES>(BLACK)
+          && !rootPos.can_castle(ANY_CASTLING))
       {
           // If the current root position is in the tablebases, then RootMoves
           // contains only moves that preserve the draw or the win.
@@ -691,7 +692,8 @@ namespace {
 
         if (    piecesCnt <= TB::Cardinality
             && (piecesCnt <  TB::Cardinality || depth >= TB::ProbeDepth)
-            &&  pos.rule50_count() == 0)
+            &&  pos.rule50_count() == 0
+            && !pos.can_castle(ANY_CASTLING))
         {
             int found, v = Tablebases::probe_wdl(pos, &found);
 

Original file line number	Diff line number	Diff line change
`@@ -256,8 +256,9 @@ void MainThread::search() {`
`256`	`256`	`}`
`257`	`257`	`else`
`258`	`258`	`{`
`259`		`- if (TB::Cardinality >= rootPos.count<ALL_PIECES>(WHITE)`
`260`		`- + rootPos.count<ALL_PIECES>(BLACK))`
	`259`	`+ if ( TB::Cardinality >= rootPos.count<ALL_PIECES>(WHITE)`
	`260`	`+ + rootPos.count<ALL_PIECES>(BLACK)`
	`261`	`+ && !rootPos.can_castle(ANY_CASTLING))`
`261`	`262`	`{`
`262`	`263`	`// If the current root position is in the tablebases, then RootMoves`
`263`	`264`	`// contains only moves that preserve the draw or the win.`
`@@ -691,7 +692,8 @@ namespace {`
`691`	`692`
`692`	`693`	`if ( piecesCnt <= TB::Cardinality`
`693`	`694`	`&& (piecesCnt < TB::Cardinality \|\| depth >= TB::ProbeDepth)`
`694`		`- && pos.rule50_count() == 0)`
	`695`	`+ && pos.rule50_count() == 0`
	`696`	`+ && !pos.can_castle(ANY_CASTLING))`
`695`	`697`	`{`
`696`	`698`	`int found, v = Tablebases::probe_wdl(pos, &found);`
`697`	`699`