Search found 2063 matches

by mar
Wed Jul 01, 2020 8:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: GCC 8.1 vs GCC 10.1
Replies: 21
Views: 735

Re: GCC 8.1 vs GCC 10.1

Right, those idiots try hard to make each new version of gcc slower than the one before. Fortunately we have expert-testers who expose them. Good job Gabor!
by mar
Wed Jun 24, 2020 3:35 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Java vs C. It's not like one would think.
Replies: 13
Views: 807

Re: Java vs C. It's not like one would think.

Right, except that such super-instructions have to be useful in the first place. For large vector/matrix operations, it would be better to simply implement these in optimized C/C++/... (or even offload to a GPU) and expose them as functions to the (scripting) language (this is what Python does, bind...
by mar
Wed Jun 24, 2020 1:40 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Java vs C. It's not like one would think.
Replies: 13
Views: 807

Re: Java vs C. It's not like one would think.

The interpreter named "JVM 64Bit" is only about a factor 1.25 slower than compiled C-Code in terms of my chess engine. For me: This is quite surprising. You seem to misunderstand what an interpreter is. JVM compiles bytecode to machine code, it may interpret, but that would be horrendlously slow (j...
by mar
Mon Jun 22, 2020 5:33 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Java vs C. It's not like one would think.
Replies: 13
Views: 807

Re: Java vs C. It's not like one would think.

Of course, C is supposed to be faster than any other language, because it is translated easily 1:1 into machine code. umm, producing optimized machine code is incredibly hard, there's a reason why LLVM is 1M SLOC. An interpreted language is only 30% slower. I think, this is the result of a great ru...
by mar
Mon Jun 22, 2020 1:40 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Java vs C. It's not like one would think.
Replies: 13
Views: 807

Re: Java vs C. It's not like one would think.

Who told you Java should be faster than C? 30% slower is actually an excellent result for Java and I'm impressed and shocked (I can confirm ~31% on my machine as well - latest 64-bit hotspot vs 64-bit gcc O3). Hotspot is very good and from what I've seen it produces faster code than C# (.NET) I wond...
by mar
Wed Jun 17, 2020 2:58 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Removing bugs from bug free functions
Replies: 20
Views: 1067

Re: Removing bugs from bug free functions

if you can use VS2019 and do a 32-bit build, you can try to enable ASAN (finally) to see if it detects any problems. 64-bit ASAN will come in the next version I think. One can never rule out compiler bugs, but these are rare. Also don't forget that in debug mode everything is pre/post-filled with sp...
by mar
Wed Jun 17, 2020 2:22 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Profile with gprof and code::blocks
Replies: 5
Views: 433

Re: Profile with gprof and code::blocks

nobody sane measures performance with optimizations disabled. you'd get totally unreliable results. nothing gets inlined, function prologue typically contains stack checks and fillers, nothing is cached in registers (everything spills), asserts are present in debug builds => typically debug builds r...
by mar
Mon Jun 08, 2020 8:02 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Just found a 55 elo bug in SlowChess 2.1
Replies: 26
Views: 2335

Re: Just found a 55 elo bug in SlowChess 2.1

Removing history updates from Ethereal lost 760 elo at STC : http://chess.grantnet.us/viewTest/4369/ Obviously, Ethereal uses history counters for some pruning decisions, so the result is worse than having an engine that doesn't depend on history anywhere. I stand by "hundreds" in any case. Move or...
by mar
Sun Jun 07, 2020 12:26 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Just found a 55 elo bug in SlowChess 2.1
Replies: 26
Views: 2335

Re: Just found a 55 elo bug in SlowChess 2.1

Because the type safety and the code analyzer are built into the language as integral parts, the compiler can tell you exactly what is wrong, where it is wrong, why it's wrong, AND how to fix it, along with a suggestion or code snippet on how to accomplish the fix. If you have never seen a Rust err...
by mar
Sun Jun 07, 2020 9:42 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Just found a 55 elo bug in SlowChess 2.1
Replies: 26
Views: 2335

Re: Just found a 55 elo bug in SlowChess 2.1

History is worth hundreds of elo, a bug there costing 50 elo is nothing outlandish. That's a bold claim. I very much doubt that. Even if your "hundreds" would be 200, I still doubt that. Even if you use history for other decisions but move ordering. LMR alone is worth what, 100-200 max perhaps, sti...