Simplify away reductions adjustment for multithreaded search

Vizvezdenec · Disservin · commit 79261bec5932 · 2024-12-22T15:28:15.000+01:00
Seem to no longer bring measurable benefit. Passed STC SMP simplification: https://tests.stockfishchess.org/tests/view/6753561a86d5ee47d954151f LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 38000 W: 9864 L: 9656 D: 18480 Ptnml(0-2): 53, 4177, 10320, 4409, 41 Passed LTC SMP simplification: https://tests.stockfishchess.org/tests/view/6753d75f86d5ee47d9541669 LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 258674 W: 66314 L: 66335 D: 126025 Ptnml(0-2): 77, 26957, 75303, 26910, 90 Passed 16 threads LTC simplification: https://tests.stockfishchess.org/tests/view/675a066286d5ee47d9542296 LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 221804 W: 56950 L: 56936 D: 107918 Ptnml(0-2): 34, 21491, 67839, 21503, 35 closes #5729 Bench: 1294909
diff --git a/src/search.cpp b/src/search.cpp
@@ -519,7 +519,7 @@ void Search::Worker::clear() {
                     h->fill(-427);
 
     for (size_t i = 1; i < reductions.size(); ++i)
-        reductions[i] = int((19.43 + std::log(size_t(options["Threads"])) / 2) * std::log(i));
+        reductions[i] = int(19.43 * std::log(i));
 
     refreshTable.clear(networks[numaAccessToken]);
 }

Original file line number	Diff line number	Diff line change
`@@ -519,7 +519,7 @@ void Search::Worker::clear() {`
`519`	`519`	`h->fill(-427);`
`520`	`520`
`521`	`521`	`for (size_t i = 1; i < reductions.size(); ++i)`
`522`		`- reductions[i] = int((19.43 + std::log(size_t(options["Threads"])) / 2) * std::log(i));`
	`522`	`+ reductions[i] = int(19.43 * std::log(i));`
`523`	`523`
`524`	`524`	`refreshTable.clear(networks[numaAccessToken]);`
`525`	`525`	`}`