Update All Accumulators

Description

Update all accumulators when doing incremental updates. StateInfo objects now form a doubly linked list by having next pointer. The initial draft has shown 0.5% speedup locally in depth 18 bench.

After this change, the speed of incremental updates now depends more on update/refresh cost model of the feature set.

Branches

• 38e0cc7b-6

• e0bfc4b6-1

• e0bfc4b6-1-PR

Tests

Test #1

Stockfish Testing Framework

Result

Passed

Stats

LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 54368 W: 14179 L: 13842 D: 26347
Ptnml(0-2): 173, 6122, 14262, 6449, 178

Test #2

Stockfish Testing Framework

Result

Passed

Stats

LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 55040 W: 14682 L: 14322 D: 26036
Ptnml(0-2): 303, 6364, 13856, 6664, 333

Identical to Test #1 but with shorter TC (5+0.05). Launched to verify the previous test.

Test #3

Stockfish Testing Framework

Result

Passed

Stats

LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 57390 W: 14555 L: 14376 D: 28459
Ptnml(0-2): 37, 5876, 16683, 6069, 30

Identical to Test #1 but with LTC and non-regression bounds. Launched to confirm that the changes do not regress under longer TCs, as it heavily depends on how the search tree is shaped.

Based on the data regarding the relationship between Elo and speedups, all the tests have shown that this patch is about 0.5~1% faster than master.