Dev Builds » 20260504-0632

You are viewing an old NCM Stockfish dev build test. You may find the most recent dev build tests using Stockfish 15 as the baseline here.

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NCM plays each Stockfish dev build 20,000 times against Stockfish 14. This yields an approximate Elo difference and establishes confidence in the strength of the dev builds.

Summary

Host Duration Avg Base NPS Games WLD Standard Elo Ptnml(0-2) Gamepair Elo

Test Detail

ID Host Base NPS Games WLD Standard Elo Ptnml(0-2) Gamepair Elo CLI PGN

Commit

Commit ID dc1686345cf29789cdb823441bf198928a5f0d66
Author anematode
Date 2026-05-04 06:32:23 UTC
Hyperbola quintessence for ARM Passed STC https://tests.stockfishchess.org/tests/view/69f44c1e1e5788938e86aa2a LLR: 2.93 (-2.94,2.94) <0.00,2.00> Total: 27680 W: 7340 L: 7053 D: 13287 Ptnml(0-2): 72, 2862, 7683, 3153, 70 x86 is unaffected Data from Joost's machine (Neoverse V2): ``` ==== master ==== ==== Bench: 2723949 ==== 1 Nodes/second : 276819933 2 Nodes/second : 273971948 3 Nodes/second : 275567995 Average (over 3): 275453292 ==== 5b54755db23a3de29407b805b85e7bbdef28df49 ==== ==== Bench: 2723949 ==== 1 Nodes/second : 282861542 2 Nodes/second : 279085277 3 Nodes/second : 279612223 Average (over 3): 280519680 (+1.8%) ``` Data from my M1 macbook ``` Result of 100 runs ================== base (./stockfish ) = 1474702 +/- 6169 test (...fish.rbit-pr) = 1500236 +/- 6690 diff = +25533 +/- 4011 speedup = +0.0173 P(speedup > 0) = 1.0000 ``` Hyperbola quintessence works nicely on ARM because it has an efficient bit reversal instruction `rbit`. This lets us avoid the large magic bitboards lookup table. Codegen looks nice (this is for rook attacks I think): ``` 0000000100001ecc <__ZN9Stockfish10attacks_bbILNS_9PieceTypeE3EEEyNS_6SquareEy>: 100001ecc: 2a0003e8 mov w8, w0 100001ed0: f002cb09 adrp x9, 0x105964000 <dyld_stub_binder+0x105964000> 100001ed4: 91200129 add x9, x9, #0x800 100001ed8: 8b081928 add x8, x9, x8, lsl #6 100001edc: a9402909 ldp x9, x10, [x8] 100001ee0: 8a01012b and x11, x9, x1 100001ee4: dac0016c rbit x12, x11 100001ee8: a941210d ldp x13, x8, [x8, #0x10] 100001eec: cb08018c sub x12, x12, x8 100001ef0: dac0018c rbit x12, x12 100001ef4: cb0d016b sub x11, x11, x13 100001ef8: ca0b018b eor x11, x12, x11 100001efc: 8a090169 and x9, x11, x9 100001f00: 8a01014b and x11, x10, x1 100001f04: dac0016c rbit x12, x11 100001f08: cb080188 sub x8, x12, x8 100001f0c: dac00108 rbit x8, x8 100001f10: cb0d016b sub x11, x11, x13 100001f14: ca0b0108 eor x8, x8, x11 100001f18: 8a0a0108 and x8, x8, x10 100001f1c: 8b090100 add x0, x8, x9 100001f20: d65f03c0 ret ``` closes https://github.com/official-stockfish/Stockfish/pull/6795 No functional change
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