New engine: Clover

[Sylwy]

Some infos about the young author:

https://www.chessprogramming.org/Luca_Metehau

[jshriver]

Hi everyone!

I'm Luca and I have recently developed a chess engine in C++.

Welcome glad to have you here! I look forward to playing and testing your engine.

[jshriver]

trying to build on ubuntu, an recommedations:

/usr/bin/ld: /tmp/ccv28ox1.o: in function `Search::search(int, int, int, unsigned short)':
main.cpp:(.text+0x6d80): undefined reference to `TB_LARGEST'
/usr/bin/ld: main.cpp:(.text+0x6d84): undefined reference to `TB_LARGEST'
/usr/bin/ld: main.cpp:(.text+0x7ecc): undefined reference to `tb_probe_wdl_impl'
/usr/bin/ld: main.cpp:(.text+0x806c): undefined reference to `TB_LARGEST'
/usr/bin/ld: main.cpp:(.text+0x8074): undefined reference to `TB_LARGEST'
/usr/bin/ld: /tmp/ccv28ox1.o: in function `Search::startPrincipalSearch(Info*)':
main.cpp:(.text+0x98bc): undefined reference to `pthread_create'
/usr/bin/ld: main.cpp:(.text+0x98cc): undefined reference to `pthread_create'
/usr/bin/ld: /tmp/ccv28ox1.o: in function `Search::setThreadCount(int) [clone .part.0]':
main.cpp:(.text+0x9de0): undefined reference to `pthread_create'
/usr/bin/ld: main.cpp:(.text+0x9df0): undefined reference to `pthread_create'
/usr/bin/ld: /tmp/ccv28ox1.o: in function `evalError(std::vector<Position, std::allocator<Position> >&, double, int)':
main.cpp:(.text+0xc1d8): undefined reference to `pthread_create'
/usr/bin/ld: /tmp/ccv28ox1.o:main.cpp:(.text+0xc1e8): more undefined references to `pthread_create' follow
/usr/bin/ld: /tmp/ccv28ox1.o: in function `UCI::Uci_Loop()':
main.cpp:(.text+0x11220): undefined reference to `tb_init_impl'

[cpeters]

g++ *.cpp *.c -march=native -Wall -O3 -pthread -o test

?

[lucametehau]

Thanks cpeters for pointing out, I forgot to add that too.
And thanks Sylwy for creating that page.

[Sylwy]

Clover 2.1.2_x64 is for sure an over 3000 Elo points chess engine. Bravo, Luca !





The author of the page in chessprogramming.wiki is Mr.Gerd Isenberg !

[thunderstruck]

Engine crashes immediately if I set hash size 2 GB or more.
I compiled a debug version and the core dump revealed it crashes always on the same line.
tt::HashTable::initTable (this=0xc65f50, size=288230376118157312) at tt.h:117
Something must be wrong in initTable().

[supersharp77]

This is strange... I tried to run my engine in Fritz 16 64-bit and it works perfectly fine...
https://pasteboard.co/JYVIxSV.png
Also, do you get any error or it just crashes? Does it print

Clover 2.1.1.3 by Luca Metehau

before crashing?

They all open for a bit and then close ...my machine is nopopcnt........your engines look to be popcount compiles...we will need two sets of compiles..popcnt and nonpopcnt....working on a big tourney setup currently..(Hurry..Thx AR)..

[lucametehau]

Thanks thunderstruck for pointing out, it was an overflow issue. I also added nopopcnt support. If you want to compile locally, I recommend you use the master code, because the release code is not updated

[Werner]

I think, the compiles are still not perfect. They run on a new processor with bmi2 and avx2, but crash at once on a processor with only popcount and avx.