| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: shaowyx
Date: Sat Nov 1 10:48:40 2025 +0100 Timestamp: 1761990520 Revert malus and associated coefficient parameters resulting from using only quiet moves Following #6226 and #6256, this patch ultimately corresponds to the revert of #6200. Parameters were tuned on 60k LTC games. STC (10+0.1 th1) was accepted: LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 167488 W: 43573 L: 43063 D: 80852 Elo +1.06 Ptnml(0-2): 506, 19644, 43004, 20014, 576 https://tests.stockfishchess.org/tests/view/68f526a4637acd2a11e721c2 LTC (60+0.6 th1) was accepted: LLR: 2.99 (-2.94,2.94) <0.50,2.50> Total: 61068 W: 15882 L: 15510 D: 29676 Elo +2.12 Ptnml(0-2): 31, 6578, 16949, 6940, 36 https://tests.stockfishchess.org/tests/view/68fa1968637acd2a11e72a0a Non-regression VLTC (180+1.8 th1) was accepted: LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 50380 W: 13087 L: 12905 D: 24388 Elo +1.26 Ptnml(0-2): 5, 5018, 14962, 5200, 5 https://tests.stockfishchess.org/tests/view/68fdc6e5637acd2a11e72f33 closes https://github.com/official-stockfish/Stockfish/pull/6378 Bench: 2530552 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Timothy Herchen
Date: Sat Nov 1 10:42:42 2025 +0100 Timestamp: 1761990162 Improve index generation The speedup seems to vary by machine. The indexing function can be changed w/o needing to understand intrinsics. Result of 100 runs ================== base (...ish_baseline) = 1719637 +/- 3233 test (./stockfish ) = 1734245 +/- 3534 diff = +14608 +/- 4868 speedup = +0.0085 P(speedup > 0) = 1.0000 closes https://github.com/official-stockfish/Stockfish/pull/6366 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Timothy Herchen
Date: Sat Nov 1 10:40:23 2025 +0100 Timestamp: 1761990023 prefetch earlier if checKEP is false Only a modest amount of work happens between the transposition table prefetch and the probe, so the probe still often stalls waiting for DRAM. The vast majority of the time (in particular, if !checkEP), the key is known much earlier in the do_move function and the latency can be better hidden. passed STC SMP https://tests.stockfishchess.org/tests/view/68f337c528e6d77fcffa066a LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 65256 W: 16806 L: 16462 D: 31988 Elo +1.83 Ptnml(0-2): 76, 7386, 17362, 7726, 78 but failed to gain STC https://tests.stockfishchess.org/tests/view/68f3378328e6d77fcffa0665 LLR: -2.94 (-2.94,2.94) <0.00,2.00> Total: 109824 W: 28523 L: 28618 D: 52683 Elo -0.30 Ptnml(0-2): 311, 11799, 30788, 11702, 312 In local tests, the speedup grows with thread count closes https://github.com/official-stockfish/Stockfish/pull/6372 No functional change see source |
| Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sat Nov 1 10:34:44 2025 +0100 Timestamp: 1761989684 Allow AccumulatorStack::size to point to one past the end this is guaranteed to be correct since we access the last element with `size - 1` closes https://github.com/official-stockfish/Stockfish/pull/6368 fixes https://github.com/official-stockfish/Stockfish/issues/6367 no functional change see source |
| Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Taras Vuk
Date: Sat Nov 1 10:28:02 2025 +0100 Timestamp: 1761989282 Increase NMP reduction when improving Passed STC: LLR: 2.93 (-2.94,2.94) <0.00,2.00> Total: 52896 W: 13904 L: 13565 D: 25427 Elo +2.23 Ptnml(0-2): 186, 6022, 13706, 6335, 199 https://tests.stockfishchess.org/tests/view/68e67d02a017f472e763dfaf Passed LTC: LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 168354 W: 43750 L: 43163 D: 81441 Elo +1.21 Ptnml(0-2): 81, 18284, 46882, 18827, 103 https://tests.stockfishchess.org/tests/view/68e79d7ba017f472e763e352 closes https://github.com/official-stockfish/Stockfish/pull/6361 bench: 2537382 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Kieren Pearson
Date: Tue Oct 14 17:46:13 2025 +0200 Timestamp: 1760456773 Use huge pages for worker data As the worker data is quite large (28MB after #6350) we can make use of huge pages as a speedup. prior to #6350 STC passed elo gaining bounds: LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 166272 W: 43479 L: 42993 D: 79800 Elo +1.02 Ptnml(0-2): 540, 17598, 46365, 18102, 531 https://tests.stockfishchess.org/tests/view/68e9f3c0d323fd15c04e3ba4 Tested the speedup on a large machine with speedtest: ==== master ==== Average (over 20): 288644510 ==== largePageWorker ==== Average (over 20): 292082422 Test after #6350: ==== rustam-cpp-testPR ==== Average (over 20): 291035351 ==== rustam-cpp-testPR-pages ==== Average (over 20): 291937367 https://github.com/official-stockfish/Stockfish/pull/6359 No functional change see source |
| Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Robert Nurnberg @ elitebook
Date: Tue Oct 14 17:34:17 2025 +0200 Timestamp: 1760456057 let CI check for mate scores outside the valid range closes https://github.com/official-stockfish/Stockfish/pull/6358 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Daniel Monroe
Date: Tue Oct 14 17:32:32 2025 +0200 Timestamp: 1760455952 Remove condition in qsearch Instead of skipping non-captures when pawn history is exceptionally high, skip all non-captures Passed non-regression STC LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 38016 W: 10018 L: 9795 D: 18203 Elo +2.04 Ptnml(0-2): 155, 4346, 9755, 4625, 127 https://tests.stockfishchess.org/tests/view/68e43d4aa017f472e763db2e Passed rebased non-regression LTC LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 96048 W: 24854 L: 24710 D: 46484 Elo +0.52 Ptnml(0-2): 47, 10504, 26780, 10644, 49 https://tests.stockfishchess.org/tests/view/68e59352a017f472e763dcf9 closes https://github.com/official-stockfish/Stockfish/pull/6355 bench 2343840 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: rustam-cpp
Date: Tue Oct 14 17:27:42 2025 +0200 Timestamp: 1760455662 bigger PAWN_HISTORY_SIZE STC (10+0.1 th1) was accepted: LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 75712 W: 19701 L: 19326 D: 36685 Elo +1.72 Ptnml(0-2): 254, 8738, 19513, 9081, 270 https://tests.stockfishchess.org/tests/view/68e286d5fa806e2e8393d160 LTC (60+0.6 th1) was accepted: LLR: 2.96 (-2.94,2.94) <0.50,2.50> Total: 108492 W: 28068 L: 27604 D: 52820 Elo +1.49 Ptnml(0-2): 60, 11639, 30390, 12091, 66 https://tests.stockfishchess.org/tests/view/68e3e564a017f472e763dac0 closes https://github.com/official-stockfish/Stockfish/pull/6350 bench 2128316 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: mstembera
Date: Tue Oct 14 17:25:48 2025 +0200 Timestamp: 1760455548 Split accumulator 3-way for avxvnni This does the same thing for x86-64-avxvnni as #6336, #6339. closes https://github.com/official-stockfish/Stockfish/pull/6347 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: dav1312
Date: Tue Oct 14 17:22:30 2025 +0200 Timestamp: 1760455350 Update get_native_properties.sh for AVXVNNI Update get_native_properties.sh to detect and report 'x86-64-avxvnni' when the CPU supports it. closes https://github.com/official-stockfish/Stockfish/pull/6346 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Daniel Samek
Date: Tue Oct 7 11:50:51 2025 +0200 Timestamp: 1759830651 Introduce 4-ply continuation correction history Passed STC: LLR: 2.94 (-2.94,2.94) <0.00,2.00> Total: 113984 W: 29752 L: 29323 D: 54909 Elo +1.31 Ptnml(0-2): 376, 13191, 29435, 13608, 382 https://tests.stockfishchess.org/tests/view/68dc3576fa806e2e8393bd93 Passed LTC: LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 80154 W: 20823 L: 20417 D: 38914 Elo +1.76 Ptnml(0-2): 47, 8600, 22383, 8994, 53 https://tests.stockfishchess.org/tests/view/68df83e0fa806e2e8393cbe8 Passed non-regression VLTC (rebased): LLR: 2.98 (-2.94,2.94) <-1.75,0.25> Total: 38158 W: 9992 L: 9805 D: 18361 Elo +1.70 Ptnml(0-2): 3, 3406, 12075, 3591, 4 https://tests.stockfishchess.org/tests/view/68e22f2afa806e2e8393d0ed closes https://github.com/official-stockfish/Stockfish/pull/6345 bench 2169281 see source |
| Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Daniel Monroe
Date: Tue Oct 7 11:49:00 2025 +0200 Timestamp: 1759830540 Make sure we don't move a nonexistent piece in SEE added assert. closes https://github.com/official-stockfish/Stockfish/pull/6342 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: mstembera
Date: Sun Oct 5 09:38:44 2025 +0200 Timestamp: 1759649924 Remove x86-64-vnni256 target When vnni256 was first introduced #3038 it was very slightly faster than vnni512 on some machines. We have since sped up vnni512 significantly (#4796 over 10% alone, #6139, and probably others I'm forgetting). Since any machine that can run vnni256 can run vnni512 this arch is no longer useful. Note, x86-64-avxvnni still covers targets that don't have AVX512 but do have VNNI on 128- and 256-bit vectors. closes https://github.com/official-stockfish/Stockfish/pull/6340 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sun Oct 5 09:33:42 2025 +0200 Timestamp: 1759649622 remove clang-format workaround closes https://github.com/official-stockfish/Stockfish/pull/6332 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 + SSSE3 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Timothy Herchen
Date: Sun Oct 5 09:33:23 2025 +0200 Timestamp: 1759649603 Split accumulator 3-Way Squeeze a tiny bit more juice from the original idea in #6336 which this is on top of. https://tests.stockfishchess.org/tests/view/68dddd85fa806e2e8393c0b9 LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 156320 W: 40925 L: 40447 D: 74948 Elo +1.06 Ptnml(0-2): 427, 17330, 42172, 17800, 431 4-way doesn't look to be better than this. https://tests.stockfishchess.org/tests/view/68dde19efa806e2e8393c0c1 closes https://github.com/official-stockfish/Stockfish/pull/6339 No functional change Co-authored-by: M Stembera <> see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: FauziAkram
Date: Sun Oct 5 09:25:44 2025 +0200 Timestamp: 1759649144 Tweak Correction History Bonus Asymmetrically Refine the correction history update by applying an asymmetric bonus based on the type of evaluation error. It differentiates between negative corrections and positive corrections. Passed STC: LLR: 2.93 (-2.94,2.94) <0.00,2.00> Total: 165184 W: 43314 L: 42807 D: 79063 Elo +1.07 Ptnml(0-2): 551, 19391, 42261, 19778, 611 https://tests.stockfishchess.org/tests/view/68cae49902c43c969fe7f008 Passed LTC: LLR: 2.95 (-2.94,2.94) <0.50,2.50> Total: 243234 W: 62765 L: 62029 D: 118440 Elo +1.05 Ptnml(0-2): 163, 25996, 68551, 26756, 151 https://tests.stockfishchess.org/tests/view/68d1c50dfa806e2e8393aa1f closes https://github.com/official-stockfish/Stockfish/pull/6338 Bench: 2746404 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: nicolasduhamel
Date: Sun Oct 5 09:23:02 2025 +0200 Timestamp: 1759648982 Adjust aspiration window Narrow the aspiration window after fail high. Passed STC: LLR: 2.98 (-2.94,2.94) <0.00,2.00> Total: 51296 W: 13550 L: 13207 D: 24539 Elo +2.32 Ptnml(0-2): 165, 5971, 13052, 6276, 184 https://tests.stockfishchess.org/tests/view/68d99afffa806e2e8393b7ae Passed LTC; LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 87780 W: 22795 L: 22375 D: 42610 Elo +1.66 Ptnml(0-2): 52, 9340, 24694, 9744, 60 https://tests.stockfishchess.org/tests/view/68dae0a6fa806e2e8393baad See the comments in #6293 discussing the mechanisms leading to issue #6296 closes https://github.com/official-stockfish/Stockfish/pull/6337 Bench: 2336606 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sun Oct 5 09:18:16 2025 +0200 Timestamp: 1759648696 Further simplify low ply history in evasions Passed Non-regression STC (vs #6308): LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 174208 W: 45414 L: 45343 D: 83451 Elo +0.14 Ptnml(0-2): 633, 20324, 45095, 20443, 609 https://tests.stockfishchess.org/tests/view/68c24be359efc3c96b611487 Passed Non-regression LTC (vs #6308): LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 110070 W: 28099 L: 27969 D: 54002 Elo +0.41 Ptnml(0-2): 56, 11919, 30962, 12035, 63 https://tests.stockfishchess.org/tests/view/68c4efa559efc3c96b611dfc closes https://github.com/official-stockfish/Stockfish/pull/6321 Bench: 2151873 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sun Sep 28 21:21:57 2025 +0200 Timestamp: 1759087317 Simplify use of low-ply history in evasions Passed Non-regression STC: LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 65024 W: 16991 L: 16804 D: 31229 Elo +1.00 Ptnml(0-2): 182, 7423, 17119, 7602, 186 https://tests.stockfishchess.org/tests/view/68c23f5459efc3c96b6113df Passed Non-regression LTC: LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 207312 W: 53126 L: 53095 D: 101091 Elo +0.05 Ptnml(0-2): 126, 21986, 59389, 22041, 114 https://tests.stockfishchess.org/tests/view/68c241e359efc3c96b6113ef closes https://github.com/official-stockfish/Stockfish/pull/6308 Bench: 2515619 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sun Sep 28 21:19:22 2025 +0200 Timestamp: 1759087162 Simplify a separate term in low ply history bonus formula Passed Non-regression STC: LLR: 2.93 (-2.94,2.94) <-1.75,0.25> Total: 211200 W: 54887 L: 54860 D: 101453 Elo +0.04 Ptnml(0-2): 719, 24894, 54296, 25023, 668 https://tests.stockfishchess.org/tests/view/68c21e7f59efc3c96b6112c8 Passed Non-regression LTC: LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 217842 W: 55587 L: 55568 D: 106687 Elo +0.03 Ptnml(0-2): 130, 23651, 61313, 23724, 103 https://tests.stockfishchess.org/tests/view/68c230ec59efc3c96b61135a closes https://github.com/official-stockfish/Stockfish/pull/6307 Bench: 2070860 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: FauziAkram
Date: Sun Sep 28 21:14:28 2025 +0200 Timestamp: 1759086868 Simplify away conthist 0 While at it, I also added the scaler note to the Lmrdepth/history formula. Passed STC: LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 25376 W: 6660 L: 6423 D: 12293 Elo +3.24 Ptnml(0-2): 77, 2947, 6403, 3184, 77 https://tests.stockfishchess.org/tests/view/68c1ccf759efc3c96b610deb Passed LTC: LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 208464 W: 53371 L: 53342 D: 101751 Elo +0.05 Ptnml(0-2): 110, 22776, 58426, 22815, 105 https://tests.stockfishchess.org/tests/view/68c1d04b59efc3c96b610e13 closes https://github.com/official-stockfish/Stockfish/pull/6304 Bench: 2029296 see source |
| Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sun Sep 28 21:12:01 2025 +0200 Timestamp: 1759086721 Simplify Probcut Clamp Further Passed Non-regression STC: LLR: 2.93 (-2.94,2.94) <-1.75,0.25> Total: 157984 W: 41116 L: 41030 D: 75838 Elo +0.19 Ptnml(0-2): 568, 18570, 40601, 18714, 539 https://tests.stockfishchess.org/tests/view/68b750518f94a4e5a7fe76cd Passed Non-regression LTC: LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 335232 W: 85443 L: 85543 D: 164246 Elo -0.10 Ptnml(0-2): 177, 36616, 94137, 36502, 184 https://tests.stockfishchess.org/tests/view/68bc767259efc3c96b61076b closes https://github.com/official-stockfish/Stockfish/pull/6303 Bench: 2213844 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Shawn Xu
Date: Sun Sep 28 21:08:58 2025 +0200 Timestamp: 1759086538 Remove quiet move streak Passed Non-regression STC: LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 67712 W: 17744 L: 17555 D: 32413 Elo +0.97 Ptnml(0-2): 204, 8030, 17274, 8069, 279 https://tests.stockfishchess.org/tests/view/68b784628f94a4e5a7fe7706 Passed Non-regression LTC: LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 196050 W: 50270 L: 50228 D: 95552 Elo +0.07 Ptnml(0-2): 122, 21465, 54813, 21499, 126 https://tests.stockfishchess.org/tests/view/68ba119d8f94a4e5a7fe7941 closes https://github.com/official-stockfish/Stockfish/pull/6299 Bench: 2238789 Co-authored-by: Daniel Monroe <> see source |
| Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Timothy Herchen
Date: Sun Sep 28 21:04:29 2025 +0200 Timestamp: 1759086269 Shave some instructions off a hot loop in affine transform On x86, GCC generates highly suboptimal code for this loop in its old form, about 2x as many instructions as necessary. This decreases throughput especially in an SMT setting. Clang does a better job but this change still has some improvement. Note that the std::ptrdiff_t type is not optional; using an unsigned type brings back the bad assembly. (Not sure why, but it seems reliable on all the GCC versions I tested.) passed STC: LLR: 2.93 (-2.94,2.94) <0.00,2.00> Total: 44672 W: 11841 L: 11527 D: 21304 Elo +2.44 Ptnml(0-2): 165, 4625, 12415, 4993, 138 https://tests.stockfishchess.org/tests/view/68d8111efa806e2e8393b10e closes https://github.com/official-stockfish/Stockfish/pull/6331 No functional change see source |