OliThink 5.9.5 is very small

[OliverBr]

OliThink 5.9.5 has only 44 kByte or 1500 lines of code.

It's even smaller than its predecessor OliThink4, which is very compact.
The mobility evaluation is very small. There are no pre-computed or texelian numbers.
Still there are quite a couple of bugs in search and pruning.

OliThink supports MacOSX, Linux and Windows and there is a 1:1 translation into Java.

[Dann Corbit]

I made a version with variable sized hash tables:


I kept the power of 2 thing, but allowed whatever fits within the request:
memory N
where N is megabytes.

[OliverBr]

Thank you very much, Dann!

May I use your code within the next version of OliThink, with some changes?

[Dann Corbit]

Thank you very much, Dann!

May I use your code within the next version of OliThink, with some changes?

Of course, any changes I make you can use without asking permission. IOW, you have my implicit permission to use any tweaks I ever make to Olithink.
I looked at the code, and I think I left out initialization of the last hash element. So that's a bug.

[Werner]

I made a version with variable sized hash tables:


I kept the power of 2 thing, but allowed whatever fits within the request:
memory N
where N is megabytes.

Hi Dann,
how to use inside Arena=
commandline parameter Memory 256 does not work here ?
or
startcommand Memory 256 does not work here ?
thanks

[Archimedes]

OliThink supports MacOSX, Linux and Windows and there is a 1:1 translation into Java.

It also works on Android (tested with Chess for Android).

OliThink 5.9.5 for Android:
https://app.box.com/s/ga6nnh7fxw01mg7hxuqe3ixv9ivgy0zs

[Ras]

I made a version with variable sized hash tables:

But memory=1 is missing in the feature announcent in line 1529 so that this will not be used. From http://hgm.nubati.net/CECP.html:
memory N
Specifies the engine can use at most N megabytes of memory. Only sent when the engine requested it through feature memory=1, and never during a game.

Also, stdlib.h should be included to use calloc() (in which case the integer variable random needs to be renamed), and the scanf() in line 1552 is using the wrong format string for the type size_t of the variable wanted.

[Dann Corbit]

Amazing that I can generate so many bugs with about ten new lines of code.

[OliverBr]

Of course, any changes I make you can use without asking permission. IOW, you have my implicit permission to use any tweaks I ever make to Olithink.

I am implementing now your code and there is something I don't understand:
Using xboard I configured 1024 MB Hashsize, but xboard sends the following string to the engine:

Code: Select all

memory 1028

What exactly is the purpose of those "4 Mbyte extra"?

[OliverBr]

But memory=1 is missing in the feature announcent in line 1529 so that this will not be used. From http://hgm.nubati.net/CECP.html:
memory N
Specifies the engine can use at most N megabytes of memory. Only sent when the engine requested it through feature memory=1, and never during a game.

Also, stdlib.h should be included to use calloc() (in which case the integer variable random needs to be renamed), and the scanf() in line 1552 is using the wrong format string for the type size_t of the variable wanted.

That's right.
The import of stdlib.h is a little annoying. Another extra line and I can't use "random" anymore, of course. I had to rename it.