Avoid recomputing moveCountPruning

gab8192 · vondele · commit f7fbc6880efa · 2023-10-08T07:52:16.000+02:00
In search, when moveCountPruning becomes true, it can never turn false again. Passed STC https://tests.stockfishchess.org/tests/view/652075ceac57711436728aac LLR: 2.94 (-2.94,2.94) <0.00,2.00> Total: 136448 W: 34923 L: 34472 D: 67053 Ptnml(0-2): 420, 15094, 36767, 15501, 442 closes #4823 Non functional change
diff --git a/src/search.cpp b/src/search.cpp
@@ -984,7 +984,8 @@ namespace {
           && bestValue > VALUE_TB_LOSS_IN_MAX_PLY)
       {
           // Skip quiet moves if movecount exceeds our FutilityMoveCount threshold (~8 Elo)
-          moveCountPruning = moveCount >= futility_move_count(improving, depth);
+          if (!moveCountPruning)
+              moveCountPruning = moveCount >= futility_move_count(improving, depth);
 
           // Reduced depth of the next LMR search
           int lmrDepth = newDepth - r;

Original file line number	Diff line number	Diff line change
`@@ -984,7 +984,8 @@ namespace {`
`984`	`984`	`&& bestValue > VALUE_TB_LOSS_IN_MAX_PLY)`
`985`	`985`	`{`
`986`	`986`	`// Skip quiet moves if movecount exceeds our FutilityMoveCount threshold (~8 Elo)`
`987`		`- moveCountPruning = moveCount >= futility_move_count(improving, depth);`
	`987`	`+ if (!moveCountPruning)`
	`988`	`+ moveCountPruning = moveCount >= futility_move_count(improving, depth);`
`988`	`989`
`989`	`990`	`// Reduced depth of the next LMR search`
`990`	`991`	`int lmrDepth = newDepth - r;`