Passed STC non-regression on avx512icl (https://tests.stockfishchess.org/tests/view/6a421b46f97ff95f78795061)
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 81632 W: 21240 L: 21075 D: 39317
Ptnml(0-2): 184, 8907, 22464, 9082, 179
Passed STC non-regression on bmi2 (https://tests.stockfishchess.org/tests/view/6a41f6f9f97ff95f7879503e)
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 78112 W: 20411 L: 20245 D: 37456
Ptnml(0-2): 188, 8449, 21632, 8583, 204
After #6845 , pext attacks are slower or equal to parallel-hyperbola attacks which works on all architectures that pext supports. SVE2 supports pext/pdep in vector registers, but it's much slower than the `rbit`-based HQ that we have on ARM, so I don't foresee the code being useful there.
Ofc I don't think we should remove the `bmi2` build or anything, because it's nice for people to be able to freely use pext when testing ideas, and I'm sure we'll some day find another use for it!
closes https://github.com/official-stockfish/Stockfish/pull/6939
No functional change
Co-authored-by: Dubslow <bunslow@gmail.com>
example of using, to avoid mixed usage of std::uint/std::int and uint/int...
```cpp
using u64 = std::uint64_t;
using u32 = std::uint32_t;
using u16 = std::uint16_t;
using u8 = std::uint8_t;
using i64 = std::int64_t;
using i32 = std::int32_t;
using i16 = std::int16_t;
using i8 = std::int8_t;
using usize = std::size_t;
using isize = std::ptrdiff_t;
#if defined(__GNUC__) && defined(IS_64BIT)
__extension__ using u128 = unsigned __int128;
__extension__ using i128 = signed __int128;
#endif
```
closes https://github.com/official-stockfish/Stockfish/pull/6874
No functional change
Over the past few months our attacks and bitboard logic got a bit more involved and target specific, so I think it makes sense to split this up a bit more into separate files.
While it's not in an ideal state I think it's first step and can be improved later, `pawn_attacks_bb` could also be moved into the attacks.h but this was more of an oversight from my side.
closes https://github.com/official-stockfish/Stockfish/pull/6833
No functional change
STC
```
LLR: 5.45 (-2.94,2.94) <0.00,2.00>
Total: 612192 W: 158602 L: 157260 D: 296330
Ptnml(0-2): 1634, 67783, 166027, 68911, 1741
```
@Torom measured:
```
sf_base = 2380902 +/- 1016 (95%)
sf_test = 2391426 +/- 1065 (95%)
diff = 10524 +/- 1336 (95%)
speedup = 0.44203% +/- 0.056% (95%)
```
I've verified that `_mm512_slli_epi16(v, 0)` gets optimized out in GCC
9+ and clang 4+. Added constants to types.h so that people messing
around with the layout of `Move` don't have to know about this part of
the code.
closes https://github.com/official-stockfish/Stockfish/pull/6670
No functional change
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
- remove the blank line between the declaration of the function and it's
comment, leads to better IDE support when hovering over a function to see it's
description
- remove the unnecessary duplication of the function name in the functions
description
- slightly refactored code for lsb, msb in bitboard.h There are still a few
things we can be improved later on, move the description of a function where
it was declared (instead of implemented) and add descriptions to functions
which are behind macros ifdefs
closes https://github.com/official-stockfish/Stockfish/pull/4840
No functional change
This introduces clang-format to enforce a consistent code style for Stockfish.
Having a documented and consistent style across the code will make contributing easier
for new developers, and will make larger changes to the codebase easier to make.
To facilitate formatting, this PR includes a Makefile target (`make format`) to format the code,
this requires clang-format (version 17 currently) to be installed locally.
Installing clang-format is straightforward on most OS and distros
(e.g. with https://apt.llvm.org/, brew install clang-format, etc), as this is part of quite commonly
used suite of tools and compilers (llvm / clang).
Additionally, a CI action is present that will verify if the code requires formatting,
and comment on the PR as needed. Initially, correct formatting is not required, it will be
done by maintainers as part of the merge or in later commits, but obviously this is encouraged.
fixes https://github.com/official-stockfish/Stockfish/issues/3608
closes https://github.com/official-stockfish/Stockfish/pull/4790
Co-Authored-By: Joost VandeVondele <Joost.VandeVondele@gmail.com>
This patch changes the pop_lsb() signature from Square pop_lsb(Bitboard*) to
Square pop_lsb(Bitboard&). This is more idomatic for C++ style signatures.
Passed a non-regression STC test:
LLR: 2.93 (-2.94,2.94) {-1.25,0.25}
Total: 21280 W: 1928 L: 1847 D: 17505
Ptnml(0-2): 71, 1427, 7558, 1518, 66
https://tests.stockfishchess.org/tests/view/6053a1e22433018de7a38e2f
We have verified that the generated binary is identical on gcc-10.
Closes https://github.com/official-stockfish/Stockfish/pull/3404
No functional change.
We remark that in current master, most of our use cases for between_bb() can be
optimized if the second parameter of the function is added to the segment. So we
change the definition of between_bb(s1, s2) such that it excludes s1 but includes s2.
We also use a precomputed array for between_bb() for another small speed gain
(see https://tests.stockfishchess.org/tests/view/604d09f72433018de7a389fb).
Passed STC:
LLR: 2.96 (-2.94,2.94) {-0.25,1.25}
Total: 18736 W: 1746 L: 1607 D: 15383
Ptnml(0-2): 61, 1226, 6644, 1387, 50
https://tests.stockfishchess.org/tests/view/60428c84ddcba5f0627bb6e4
Yellow LTC:
LTC:
LLR: -3.00 (-2.94,2.94) {0.25,1.25}
Total: 39144 W: 1431 L: 1413 D: 36300
Ptnml(0-2): 13, 1176, 17184, 1178, 21
https://tests.stockfishchess.org/tests/view/605128702433018de7a38ca1
Closes https://github.com/official-stockfish/Stockfish/pull/3397
---------
Verified for correctness by running perft on the following position:
./stockfish
position fen 4rrk1/1p1nq3/p7/2p1P1pp/3P2bp/3Q1Bn1/PPPB4/1K2R1NR w - - 40 21
go perft 6
Nodes searched: 6136386434
--------
No functional change
This change simplifies control flow in the generate_moves function which ensures the compiler doesn't duplicate work due to possibly not resolving pureness of the function calls. Also the biggest change is the removal of the unnecessary condition checking for empty b in a convoluted way. The rationale for removal of this condition is that computing attacks_bb with occupancy is not much more costly than computing pseudo attacks and overall the condition (also being likely unpredictable) is a pessimisation.
This is inspired by previous changes by @BM123499.
Passed STC:
LLR: 2.94 (-2.94,2.94) {-0.25,1.25}
Total: 88040 W: 8172 L: 7931 D: 71937
Ptnml(0-2): 285, 6128, 30957, 6361, 289
https://tests.stockfishchess.org/tests/view/5ffc28386019e097de3ef1c7
closes https://github.com/official-stockfish/Stockfish/pull/3300
No functional change.
- "discovered check" (instead of "discovery check")
- "en passant" (instead of "en-passant")
- "pseudo-legal" before a noun (instead of "pseudo legal")
- "3-fold" (instead of "3fold")
closes https://github.com/official-stockfish/Stockfish/pull/3294
No functional change.
