Commit Graph
6925 Commits
Author SHA1 Message Date
FauziAkramandJoost VandeVondele 9045fdb227 Add depth condition
Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 103360 W: 26941 L: 26530 D: 49889
Ptnml(0-2): 291, 11964, 26770, 12353, 302
https://tests.stockfishchess.org/tests/view/68863547966ed85face24a6f

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 115128 W: 29734 L: 29258 D: 56136
Ptnml(0-2): 48, 12406, 32182, 12878, 50
https://tests.stockfishchess.org/tests/view/68864f867b562f5f7b7312f2

closes https://github.com/official-stockfish/Stockfish/pull/6184

Bench: 2972498
2025-07-28 19:49:05 +02:00
FauziAkramandJoost VandeVondele 4fcfb0b4b7 Tweak the logic for setting the improving flag
Tweak the logic for setting the improving flag when the static evaluation is significantly higher than alpha.

Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 92320 W: 24057 L: 23664 D: 44599
Ptnml(0-2): 247, 10689, 23893, 11086, 245
https://tests.stockfishchess.org/tests/view/68860aba966ed85face248a1

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 281292 W: 72496 L: 71683 D: 137113
Ptnml(0-2): 135, 30289, 78995, 31082, 145
https://tests.stockfishchess.org/tests/view/6886168c966ed85face24962

closes https://github.com/official-stockfish/Stockfish/pull/6180

Bench: 3200439
2025-07-28 19:45:13 +02:00
pb00067andJoost VandeVondele 402602a70d Simplify static evaluation difference to move ordering logic
Passed STC simplification bounds
https://tests.stockfishchess.org/tests/view/686fcb091451bd6fb83082bc
LLR: 2.92 (-2.94,2.94) <-1.75,0.25>
Total: 762816 W: 196717 L: 197295 D: 368804
Ptnml(0-2): 2052, 90457, 196853, 90109, 1937

Passed LTC simplification bounds
https://tests.stockfishchess.org/tests/view/68808d316e17e7fa3939b35d
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 44736 W: 11499 L: 11303 D: 21934
Ptnml(0-2): 24, 4766, 12586, 4974, 18

closes https://github.com/official-stockfish/Stockfish/pull/6176

bench: 2684407
2025-07-28 19:40:15 +02:00
Guenther DemetzandJoost VandeVondele b6082ba750 Simplify search functions according DRY principle
Passed STC non-regression bounds
https://tests.stockfishchess.org/tests/view/6870db4bfa93cf16d3bb286a
LLR: 3.00 (-2.94,2.94) <-1.75,0.25>
Total: 182016 W: 46735 L: 46673 D: 88608
Ptnml(0-2): 368, 19895, 50465, 19867, 413

closes https://github.com/official-stockfish/Stockfish/pull/6161

no functional change
2025-07-28 19:35:28 +02:00
Muzhen GamingandJoost VandeVondele 90c83c381f VVLTC Search Tune
alues were tuned with 125k VVLTC games.

Passed VVLTC 1st sprt:
https://tests.stockfishchess.org/tests/view/68865feb7b562f5f7b731341
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 39640 W: 10380 L: 10109 D: 19151
Ptnml(0-2): 5, 3556, 12424, 3833, 2

Passed VVLTC 2nd sprt:
https://tests.stockfishchess.org/tests/view/68864dfa7b562f5f7b7312ee
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 25972 W: 6807 L: 6537 D: 12628
Ptnml(0-2): 0, 2294, 8132, 2556, 4

closes https://github.com/official-stockfish/Stockfish/pull/6188

Bench: 3143696
2025-07-28 19:33:00 +02:00
aronpetkovskiandJoost VandeVondele a516b517d3 Simplify eval >= beta condition from NMP
It seems that now only checking if static eval is above beta by some margin is all that's necessary.

Passed Non-Regression STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 227264 W: 58430 L: 58421 D: 110413
Ptnml(0-2): 532, 26559, 59454, 26542, 545
https://tests.stockfishchess.org/tests/view/68763a77432ca24f6388c766

Passed Non-Regression LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 72048 W: 18622 L: 18455 D: 34971
Ptnml(0-2): 26, 7775, 20272, 7908, 43
https://tests.stockfishchess.org/tests/view/687c9f2b6e17e7fa3939b0c5

closes https://github.com/official-stockfish/Stockfish/pull/6175

Bench: 2759840
2025-07-24 10:38:13 +02:00
Daniel MonroeandJoost VandeVondele 92514fd3a2 Simplify away a term in see pruning
This change only sets the margin to 0 when depth <= 2 and margin <= 42 which
never has a difference, thus non-functional

Passed non-regression STC
LLR: 3.51 (-2.94,2.94) <-1.75,0.25>
Total: 306976 W: 78935 L: 78961 D: 149080
Ptnml(0-2): 630, 34097, 84067, 34057, 637
https://tests.stockfishchess.org/tests/view/68708015fa93cf16d3bb2782

closes https://github.com/official-stockfish/Stockfish/pull/6170

No functional change
2025-07-24 10:32:41 +02:00
DisservinandJoost VandeVondele e88ccfd835 Prevent accidential misuse of TUNE()
Writing a TUNE expression like

int smallNetThreshold = 962;
TUNE(smallNetThreshold, 850, 1050);

is wrong and can lead to a weird binary. It should thus fail to even compile,
with the proper intellisense you'll also see the error directly in your editor.

A cheap way to prevent this is to disallow any fundamental type in the parameter list.

closes https://github.com/official-stockfish/Stockfish/pull/6164

No functional change
2025-07-24 10:28:17 +02:00
FauziAkramandJoost VandeVondele bdc393d3a2 Correct comment
closes https://github.com/official-stockfish/Stockfish/pull/6159

No functional change
2025-07-24 10:26:15 +02:00
Daniel SamekandJoost VandeVondele 2c9a1871ae Add offsets to history updates.
All parameters were tuned on 60k STC games (https://tests.stockfishchess.org/tests/view/6867ef49fe0f2fe354c0c735).

Passed STC:
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 60576 W: 15794 L: 15444 D: 29338
Ptnml(0-2): 141, 7003, 15642, 7369, 133
https://tests.stockfishchess.org/tests/view/686d5af11451bd6fb830772a

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 58722 W: 15159 L: 14799 D: 28764
Ptnml(0-2): 19, 6259, 16455, 6599, 29
https://tests.stockfishchess.org/tests/view/686f9fd51451bd6fb83081c9

closes https://github.com/official-stockfish/Stockfish/pull/6158

bench: 2706299
2025-07-24 10:24:08 +02:00
FauziAkramandJoost VandeVondele 793110ca19 Remove !ttData.move condition from cutNode reduction
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 118080 W: 30427 L: 30298 D: 57355
Ptnml(0-2): 290, 13880, 30561, 14029, 280
https://tests.stockfishchess.org/tests/view/6853f9bc038630d25f468670

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 232272 W: 59187 L: 59182 D: 113903
Ptnml(0-2): 111, 25430, 65014, 25505, 76
https://tests.stockfishchess.org/tests/view/68585c40a596a06817bb922e

closes https://github.com/official-stockfish/Stockfish/pull/6157

bench: 2227361
2025-07-24 10:19:10 +02:00
Shawn XuandJoost VandeVondele e2aa125570 Consistent syntax for class members
Currently, search.cpp uses three different syntax when accessing class member variables

* thisThread object references. This was a remnant from when pos.this_thread() was necessary for thread-local variable access
* this object references
* implicit member variable access

This PR aims to deprecate thisThread and standardize this syntax to implicit variable access, which is consistent with the rest of SF's codebase.

closes https://github.com/official-stockfish/Stockfish/pull/6154

no functional change
2025-07-24 10:13:24 +02:00
87andJoost VandeVondele 8c2d21f91a Speedup movegen with VBMI2
Passed STC
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 166720 W: 43191 L: 42701 D: 80828
Ptnml(0-2): 348, 18567, 45069, 18999, 377
https://tests.stockfishchess.org/tests/view/686ae98dfe0f2fe354c0c867

Refactor movegen to emit to a vector with 16-bit elements, which enables a
speedup with AVX512-VBMI2 when writing moves to the move list.

Very crude timing measurements of perft via timing ./stockfish "go perft 7"
demonstrates approximately 17% perft speedup:

Summary
  ./Stockfish-dev/src/stockfish 'go perft 7' ran
    1.17 ± 0.04 times faster than ./Stockfish-base/src/stockfish 'go perft 7'

Estimated overall nps increase of 0.4% via speedtest: 33605229 -> 33749825
(many thanks JonathanHallstrom).

The corresponding arch is avx512icl as it is a good baseline for consumer
avx-512 feature set support; Intel Ice Lake was the first consumer AVX-512 CPU
and it is a decent subset of what AMD Zen 4 supports.

closes https://github.com/official-stockfish/Stockfish/pull/6153

No functional change
2025-07-24 10:08:35 +02:00
Daniel MonroeandJoost VandeVondele c13f883dc4 simplify away TT history term
Passed simplification STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 163168 W: 42136 L: 42055 D: 78977
Ptnml(0-2): 410, 19224, 42212, 19351, 387
https://tests.stockfishchess.org/tests/view/684e16ee703522d4f129c9e9

Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 303144 W: 77580 L: 77647 D: 147917
Ptnml(0-2): 150, 33110, 85134, 33013, 165
https://tests.stockfishchess.org/tests/view/6852ff97703522d4f129d5f7

closes https://github.com/official-stockfish/Stockfish/pull/6152

bench: 2294774
2025-07-24 09:59:00 +02:00
Daniel MonroeandJoost VandeVondele a43f12ef08 Simplify away constants in statscore
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 317280 W: 81589 L: 81678 D: 154013
Ptnml(0-2): 799, 37651, 81847, 37526, 817
https://tests.stockfishchess.org/tests/view/684e197a703522d4f129c9f0

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 174816 W: 44656 L: 44593 D: 85567
Ptnml(0-2): 83, 19064, 49058, 19113, 90
https://tests.stockfishchess.org/tests/view/6858aa54a596a06817bb924f

closes https://github.com/official-stockfish/Stockfish/pull/6150

bench: 2508140
2025-07-24 09:56:36 +02:00
FauziAkramandJoost VandeVondele 6a09a24cd8 Remove depth condition from ttCapture reduction
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 25920 W: 6822 L: 6593 D: 12505
Ptnml(0-2): 54, 2932, 6783, 3113, 78
https://tests.stockfishchess.org/tests/view/6853f9c2038630d25f468672

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 177318 W: 45339 L: 45278 D: 86701
Ptnml(0-2): 85, 19333, 49765, 19388, 88
https://tests.stockfishchess.org/tests/view/6854468a038630d25f4686c0

closes https://github.com/official-stockfish/Stockfish/pull/6149

bench: 2437275
2025-07-24 09:52:35 +02:00
Daniel MonroeandJoost VandeVondele 62f08568cd Simplify PV term in lmr
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 204000 W: 52541 L: 52506 D: 98953
Ptnml(0-2): 561, 24133, 52589, 24144, 573
https://tests.stockfishchess.org/tests/view/684f24ce703522d4f129cab5

Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 156150 W: 39890 L: 39807 D: 76453
Ptnml(0-2): 82, 16882, 44043, 17007, 61
https://tests.stockfishchess.org/tests/view/6855d8bf1d0d9fc6587538f8

closes https://github.com/official-stockfish/Stockfish/pull/6148

bench 2766493
2025-07-24 09:49:43 +02:00
FauziAkramandDisservin ce73441f20 Simplify sudden death time optimization
Passed Sudden Death STC:
https://tests.stockfishchess.org/tests/view/68455fe5375c2b77d9855351
LLR: 2.91 (-2.94,2.94) <-1.75,0.25>
Total: 49248 W: 13008 L: 12798 D: 23442
Ptnml(0-2): 309, 5491, 12821, 5687, 316

Passed Sudden Death LTC:
https://tests.stockfishchess.org/tests/view/6845a392375c2b77d98553cf
LLR: 3.01 (-2.94,2.94) <-1.75,0.25>
Total: 551070 W: 141699 L: 142031 D: 267340
Ptnml(0-2): 1923, 60608, 150916, 60054, 2034

Passed Standard STC:
https://tests.stockfishchess.org/tests/view/683c5ebb6ec7634154f9d989
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 142624 W: 36808 L: 36709 D: 69107
Ptnml(0-2): 302, 15448, 39745, 15483, 334

Passed Standard LTC:
https://tests.stockfishchess.org/tests/view/683f1a4f6ec7634154f9dc5a
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 146922 W: 37381 L: 37296 D: 72245
Ptnml(0-2): 69, 13552, 46117, 13671, 52

closes https://github.com/official-stockfish/Stockfish/pull/6132

Bench: 2249459
2025-07-02 18:41:46 +02:00
FauziAkramandDisservin e695b9537e Remove eval & beta diff from NM reduction
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 43456 W: 11178 L: 10966 D: 21312
Ptnml(0-2): 114, 5078, 11114, 5326, 96
https://tests.stockfishchess.org/tests/view/6849ae13e84567164b5c9de9

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 63090 W: 16302 L: 16125 D: 30663
Ptnml(0-2): 37, 6837, 17603, 7048, 20
https://tests.stockfishchess.org/tests/view/684ab516e84567164b5ca02f

closes https://github.com/official-stockfish/Stockfish/pull/6134

Bench: 2249459
2025-07-02 18:41:46 +02:00
mstemberaandDisservin ce7254b5ea Optimize find_nnz() using AVX512
About a 1% speedup for ARCH x86-64-avx512 and x86-64-vnni512.

Note:  This could be optimized further if we wanted to add an ARCH
supporting VBMI2 which is even more modern than VNNI.

https://en.wikichip.org/wiki/x86/avx512_vbmi2

closes https://github.com/official-stockfish/Stockfish/pull/6139

No functional change
2025-07-02 18:41:45 +02:00
MinetaSandDisservin ea85a54fef Fix trivial errors in Makefile
1. Remove "default" rule as "default" has no special meaning as a rule
name. Make runs the very first rule whose name doesn't begin with a dot
(which is "help" currently).

2. Make "format" rule not update dependencies.

closes https://github.com/official-stockfish/Stockfish/pull/6140

No functional change
2025-07-02 18:32:12 +02:00
Robert Nurnberg @ elitebookandDisservin 84e2f3851d Introduce a constant for ValueList size in search()
Having the size of these lists in two separate places likely contributed
to the crashes seen during the recent tuning attempt
https://tests.stockfishchess.org/tests/view/685c413343ce022d15794536.

Thanks to @MinetaS for spotting this.

closes https://github.com/official-stockfish/Stockfish/pull/6142

No functional change
2025-07-02 18:32:02 +02:00
Daniel MonroeandDisservin 3a0fff96cf Simplify quiet move streak logic
Passed non-regression STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 148960 W: 38409 L: 38312 D: 72239
Ptnml(0-2): 372, 17664, 38318, 17747, 379
https://tests.stockfishchess.org/tests/view/684c5773703522d4f129c5f7

Passed non-regression LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 180720 W: 46188 L: 46130 D: 88402
Ptnml(0-2): 84, 19608, 50929, 19644, 95
https://tests.stockfishchess.org/tests/view/68505fa5703522d4f129cbab

closes https://github.com/official-stockfish/Stockfish/pull/6143

Bench: 2055894
2025-07-02 18:31:04 +02:00
Shawn XuandDisservin 318c948c4d Remove non-functional low-ply history fill
lowPlyHistory is always cleared at the start of `iterative_deepening`, so clearing it here is non-functional.

closes https://github.com/official-stockfish/Stockfish/pull/6144

No functional change
2025-07-02 18:31:04 +02:00
Daniel MonroeandDisservin a7a56c41f6 Simplify history term in futility pruning
Passed simplification STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 298816 W: 76814 L: 76881 D: 145121
Ptnml(0-2): 726, 35477, 77057, 35434, 714
https://tests.stockfishchess.org/tests/view/683f440f6ec7634154f9dc7f

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 237774 W: 60801 L: 60802 D: 116171
Ptnml(0-2): 91, 26088, 66532, 26083, 93
https://tests.stockfishchess.org/tests/view/68441189ffbc71bd236778de

closes https://github.com/official-stockfish/Stockfish/pull/6130

Bench: 2411502
2025-07-02 18:31:04 +02:00
pb00067andDisservin 34b75f1575 Restore integrity of MovePicker::can_move_king_or_pawn
PR6005 broken by PR6071

passed STC non regression
https://tests.stockfishchess.org/tests/view/6839791f6ec7634154f9d312
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 31776 W: 8353 L: 8130 D: 15293
Ptnml(0-2): 74, 3566, 8382, 3795, 71

passed LTC non-regression
https://tests.stockfishchess.org/tests/view/6839c87a6ec7634154f9d367
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 120756 W: 31015 L: 30899 D: 58842
Ptnml(0-2): 50, 12732, 34703, 12838, 55

closes https://github.com/official-stockfish/Stockfish/pull/6119

Bench: 1945300
2025-07-02 18:31:02 +02:00
disservinandGitHub 15555e8f4a Disable linux gcc riscv64 (#6145)
Temporarily disable it, until we figure out the toolchain issues which are causing the crashes.

closes https://github.com/official-stockfish/Stockfish/pull/6145

No functional change
2025-06-29 12:33:20 +02:00
Shawn XuandJoost VandeVondele 5337edfdb6 remove non-functional else
since we break out of the loop in the other branch

closes https://github.com/official-stockfish/Stockfish/pull/6116

no functional change
2025-06-02 22:12:37 +02:00
Daniel MonroeandJoost VandeVondele 9ac756695e reduce depth by 5 in probcut
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 63328 W: 16402 L: 16213 D: 30713
Ptnml(0-2): 174, 7378, 16340, 7629, 143
https://tests.stockfishchess.org/tests/view/6833530e6ec7634154f9be7f

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 69936 W: 17795 L: 17625 D: 34516
Ptnml(0-2): 29, 7631, 19474, 7809, 25
https://tests.stockfishchess.org/tests/view/68335e386ec7634154f9c266

closes https://github.com/official-stockfish/Stockfish/pull/6120

Bench: 2307268
2025-06-02 22:09:11 +02:00
Daniel MonroeandJoost VandeVondele 254b6d5e85 Simplify corrections in extension margins
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 96192 W: 25002 L: 24852 D: 46338
Ptnml(0-2): 242, 10868, 25716, 11038, 232
https://tests.stockfishchess.org/tests/view/683b44cb6ec7634154f9d6ac

Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 83334 W: 21473 L: 21317 D: 40544
Ptnml(0-2): 37, 8877, 23674, 9051, 28
https://tests.stockfishchess.org/tests/view/683b79786ec7634154f9d75a

closes https://github.com/official-stockfish/Stockfish/pull/6117

Bench: 2294814
2025-06-02 22:05:11 +02:00
Shawn XuandJoost VandeVondele 259bdaaa9f Remove an unnecessary bound check
When failing high, it is always true that `alpha < beta` and `beta <=
bestValue`. Therefore if alpha and bestValue is not in decisive range, it is
guaranteed that beta is not.

closes https://github.com/official-stockfish/Stockfish/pull/6115

no functional change
2025-06-02 21:57:19 +02:00
Shawn XuandJoost VandeVondele c9af7674bc Introduce Secondary TT Aging
When a high-depth TT entry fail to produce a cutoff, decrease the stored depth
by 1. This is intended to help cases such as #5023
(https://github.com/official-stockfish/Stockfish/issues/5023#issuecomment-2814209391),
where entries with extremely high depths prevent TT cutoffs, contributing to
search explosions.

Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 128800 W: 33502 L: 33053 D: 62245
Ptnml(0-2): 331, 15084, 33149, 15477, 359
https://tests.stockfishchess.org/tests/view/683958e56ec7634154f9d2a9

Passed LTC:
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 63288 W: 16376 L: 16005 D: 30907
Ptnml(0-2): 26, 6712, 17798, 7081, 27
https://tests.stockfishchess.org/tests/view/683aa4026ec7634154f9d469

closes https://github.com/official-stockfish/Stockfish/pull/6113

Bench: 2144705
2025-06-02 21:55:55 +02:00
Daniel MonroeandJoost VandeVondele 3747a19937 Simplify away depth condition in IIR
Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 359520 W: 92714 L: 92849 D: 173957
Ptnml(0-2): 977, 42640, 92614, 42599, 930
https://tests.stockfishchess.org/tests/view/6833705d6ec7634154f9c302

Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 201756 W: 51544 L: 51507 D: 98705
Ptnml(0-2): 89, 21965, 56728, 22012, 84
https://tests.stockfishchess.org/tests/view/68338e386ec7634154f9c790

Passed simplification VLTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 48558 W: 12675 L: 12492 D: 23391
Ptnml(0-2): 9, 4779, 14516, 4970, 5
https://tests.stockfishchess.org/tests/view/6838e0b26ec7634154f9d25b

closes https://github.com/official-stockfish/Stockfish/pull/6112

Bench: 2302583
2025-06-02 21:52:38 +02:00
Daniel MonroeandJoost VandeVondele 70ff5e3163 Simplify away cutoff term in prior countermove bonus
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 61120 W: 16010 L: 15819 D: 29291
Ptnml(0-2): 150, 7105, 15869, 7276, 160
https://tests.stockfishchess.org/tests/view/683560226ec7634154f9ce0f

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 225090 W: 57555 L: 57543 D: 109992
Ptnml(0-2): 104, 24367, 63603, 24355, 116
https://tests.stockfishchess.org/tests/view/6836420c6ec7634154f9cf5c

closes https://github.com/official-stockfish/Stockfish/pull/6111

Bench: 2472910
2025-06-02 21:49:43 +02:00
Daniel MonroeandJoost VandeVondele ddefd6eb6b Simplify away check term in statscore
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 61696 W: 16031 L: 15841 D: 29824
Ptnml(0-2): 151, 7160, 16046, 7330, 161
https://tests.stockfishchess.org/tests/view/68353fcc6ec7634154f9cdd5

Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 237990 W: 60994 L: 60995 D: 116001
Ptnml(0-2): 95, 25964, 66903, 25913, 120
https://tests.stockfishchess.org/tests/view/683642256ec7634154f9cf5e

closes https://github.com/official-stockfish/Stockfish/pull/6110

Bench: 2521003
2025-06-02 21:47:26 +02:00
Nonlinear2andJoost VandeVondele 8da3c2155a Simplify NMP eval in qsearch
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/6834e9436ec7634154f9cd6e
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 24864 W: 6626 L: 6394 D: 11844
Ptnml(0-2): 62, 2806, 6477, 3012, 75

Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/683598fd6ec7634154f9ce82
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 200148 W: 51461 L: 51424 D: 97263
Ptnml(0-2): 92, 21672, 56503, 21721, 86

closes https://github.com/official-stockfish/Stockfish/pull/6109

Bench: 2316591
2025-06-02 21:44:29 +02:00
Carlos EsparzaandJoost VandeVondele 5695486db9 Fix outdated comment
closes https://github.com/official-stockfish/Stockfish/pull/6108

No functional change
2025-06-02 21:40:13 +02:00
Robert Nurnberg @ elitebookandJoost VandeVondele 9debc540e5 Fix clang-format version in CONTRIBUTING.md
closes https://github.com/official-stockfish/Stockfish/pull/6107

No functional change
2025-06-02 21:38:53 +02:00
Shawn XuandJoost VandeVondele d0212906bd Simplify stat eval history adjustment further
closes https://github.com/official-stockfish/Stockfish/pull/6106

bench 2074807
2025-06-02 21:37:37 +02:00
mstemberaandJoost VandeVondele 29b0c07ac8 Simplify Position::pieces()
closes https://github.com/official-stockfish/Stockfish/pull/6104

No functional change
2025-06-02 21:28:18 +02:00
mstemberaandJoost VandeVondele d27298d7dc Remove unused threatenedPieces
threatenedPieces is no longer used since #6023

Also can_move_king_or_pawn() can be const.
Also remove a couple of redundant declarations.

closes https://github.com/official-stockfish/Stockfish/pull/6101

No functional change
2025-06-02 21:24:38 +02:00
Shawn XuandJoost VandeVondele dc85c5a4c9 Remove nnz lookup table load optimization
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 63296 W: 16491 L: 16311 D: 30494
Ptnml(0-2): 129, 6624, 17972, 6784, 139
https://tests.stockfishchess.org/tests/view/6833ce486ec7634154f9cb22

Passed 2nd Non-regression STC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 369568 W: 95314 L: 95451 D: 178803
Ptnml(0-2): 897, 40231, 102601, 40222, 833
https://tests.stockfishchess.org/tests/view/68355c956ec7634154f9ce07

closes https://github.com/official-stockfish/Stockfish/pull/6100

no functional change
2025-06-02 21:21:54 +02:00
Daniel MonroeandJoost VandeVondele 9fd40b9ea8 Simplify tt depth in stat eval history adjustment
Passed simplification STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 102208 W: 26498 L: 26349 D: 49361
Ptnml(0-2): 284, 12095, 26166, 12306, 253
https://tests.stockfishchess.org/tests/view/683354c76ec7634154f9be88

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 133422 W: 34050 L: 33945 D: 65427
Ptnml(0-2): 56, 14473, 37559, 14556, 67
https://tests.stockfishchess.org/tests/view/683363626ec7634154f9c298

closes https://github.com/official-stockfish/Stockfish/pull/6099

Bench: 2652411
2025-06-02 21:19:17 +02:00
Daniel MonroeandJoost VandeVondele dfa176fc7e Small tt verify simplification
Also fix probcut comment

Passed non-regression STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 69728 W: 18080 L: 17909 D: 33739
Ptnml(0-2): 161, 7157, 20044, 7354, 148
https://tests.stockfishchess.org/tests/view/68324b116ec7634154f9b478

closes https://github.com/official-stockfish/Stockfish/pull/6094

No functional change
2025-06-02 21:15:56 +02:00
FauziAkramandJoost VandeVondele 9b79b75c9b Enforce minimum compiler versions
gcc 9.3
clang 10

using unsupported compiler versions will generate an error,
older version might miscompile SF

CI: improves output on failed bench output

closes https://github.com/official-stockfish/Stockfish/pull/6032

No functional change
2025-06-02 21:09:19 +02:00
FauziAkramandJoost VandeVondele 73c55e8949 Simplify Double Margin Formula
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 267296 W: 69214 L: 69248 D: 128834
Ptnml(0-2): 760, 31511, 69141, 31475, 761
https://tests.stockfishchess.org/tests/view/682f5d9a6ec7634154f9b01e

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 67872 W: 17460 L: 17289 D: 33123
Ptnml(0-2): 25, 7238, 19243, 7401, 29
https://tests.stockfishchess.org/tests/view/6833074b6ec7634154f9b5ae

Passed VLTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 118000 W: 30337 L: 30222 D: 57441
Ptnml(0-2): 15, 11783, 35289, 11898, 15
https://tests.stockfishchess.org/tests/view/683336c56ec7634154f9ba46

closes https://github.com/official-stockfish/Stockfish/pull/6097

Bench: 2312696
2025-05-25 21:31:12 +02:00
ppigazziniandJoost VandeVondele e3adfaf8fc build & ci: update to NDK r27c API level 29
Update to the latest LTS version NDK r27c (27.2.12479018),
the previous NDK are unsupported by Google, see:
https://developer.android.com/ndk/downloads

A build with NDK r27c and API level < 29 returns this error:
"executable's TLS segment is underaligned: alignment is 8 (skew 0), needs to be at least 64 for ARM64 Bionic"

Update the API level to 29 to use the native ELF LTS and avoid the error:
https://android.googlesource.com/platform/bionic/+/HEAD/docs/elf-tls.md
https://android.googlesource.com/platform/bionic/+/HEAD/android-changes-for-ndk-developers.md#elf-tls-available-for-api-level-29

A dynamic link build of Stockfish uses these libraries:

ldd stockfish-android-armv8-dynamic-api35
        libm.so => /system/lib64/libm.so
        libdl.so => /system/lib64/libdl.so
        libc.so => /system/lib64/libc.so
        ld-android.so => /system/lib64/ld-android.so

ld-android.so : the dynamic linker used by Android (on Linux is named ld-linux.so),
                responsible for loading and linking shared libraries into an executable at runtime.
libdl.so      : interface/library layer that provides function for dynamic loading,
                relies on the underlying functionality provided by the dynamic linker
libm.so       : math library for Android
libc.so       : standard C library for Android

References:
Doc for native (C/C++) API
https://developer.android.com/ndk/guides/stable_apis

C libraries (libc, libm, libdl):
https://developer.android.com/ndk/guides/stable_apis#c_library

Bionic changes with API levels:
https://android.googlesource.com/platform/bionic/+/HEAD/docs/status.md

NDK r27c build system:
https://android.googlesource.com/platform/ndk/+/ndk-r27-release/docs/BuildSystemMaintainers.md

CI: Update to NDK r27c (27.2.12479018), the default version in GitHub runner,
to switch to a recent clang 18.

A PGO build requires static linking, because the NDK doesn't ship
the Android loaders (linker/linker64), see:
https://groups.google.com/g/android-ndk/c/3Ep6zD3xxSY

The API level should not be an issue when distributing a static build,
use the API 29, the oldest one not affected by the LTS alignement issue.

closes https://github.com/official-stockfish/Stockfish/pull/6081

No functional change
2025-05-25 21:28:53 +02:00
Кирилл ЗариповandJoost VandeVondele bebffc5622 Adjust futility pruning thresholds using history
Passed STC:
https://tests.stockfishchess.org/tests/view/6833095a6ec7634154f9b5b3
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 56896 W: 14946 L: 14604 D: 27346
Ptnml(0-2): 117, 6674, 14561, 6942, 154

Passed LTC:
https://tests.stockfishchess.org/tests/view/6833179d6ec7634154f9b5da
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 200742 W: 51660 L: 51012 D: 98070
Ptnml(0-2): 96, 21520, 56473, 22204, 78

Passed Non-regression SMP STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 29080 W: 7591 L: 7373 D: 14116
Ptnml(0-2): 38, 3178, 7881, 3414, 29
https://tests.stockfishchess.org/tests/view/6833689d6ec7634154f9c2ba

closes https://github.com/official-stockfish/Stockfish/pull/6092

Bench: 2305697
2025-05-25 21:24:09 +02:00
Shawn XuandJoost VandeVondele 00b1540e01 Always Decrease Reduction on TTMove
Passed VVLTC w/ LTC Bounds:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 57792 W: 15005 L: 14676 D: 28111
Ptnml(0-2): 2, 5241, 18082, 5568, 3
https://tests.stockfishchess.org/tests/view/682a0e3c6ec7634154f9a07e

Passed VVLTC w/ STC Bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 372298 W: 96342 L: 95655 D: 180301
Ptnml(0-2): 37, 34598, 116181, 35307, 26
https://tests.stockfishchess.org/tests/view/682a45b16ec7634154f9a3b3

STC Elo Estimate:
Elo: 0.15 ± 1.4 (95%) LOS: 58.3%
Total: 59612 W: 15414 L: 15388 D: 28810
Ptnml(0-2): 166, 6959, 15527, 6991, 163
nElo: 0.30 ± 2.8 (95%) PairsRatio: 1.00
https://tests.stockfishchess.org/tests/view/68335d276ec7634154f9c25c

closes https://github.com/official-stockfish/Stockfish/pull/6095

bench 2634355
2025-05-25 21:19:59 +02:00
Daniel SamekandJoost VandeVondele 805a2c1672 Simplify FutilityMoveCount
Inlined condition, instead of a function.

closes https://github.com/official-stockfish/Stockfish/pull/6096

no functional change
2025-05-25 21:12:27 +02:00