Wednesday, March 19, 2008

64-bit Forth

One of the limitations in building larger EGDB lies in the biggest continuous memory that can be allocated in 32-bit system. Theoretically, 4G can be allocated. However, I can only manage to allocate around 1.4G in VFX Forth in my 32-bit intel box running Windows XP. I had a 4 core 64-bit system for a long time, but the 32-bit VFX Forth system can only get 1.4G memory again even though I have 8G sitting on the main board. Due to this reason, the biggest endgame databases I can build are with 11.2G (1.4G x 8) elements. As far as I know, there is no 64-bit Forth available for Windows at this time. The only one I know is gForth for Linux. Recently, I installed Ubuntu linux on my 64-bit system and tried out gForth. Converting my endgame program to gForth and to 64-bit is surprisingly easy. Suddenly, I have the capacity to produce endgame databases larger than the ones with 11.2G elements. Unfortunately, gForth is not known for its speed. It is estimated to be about 10x slower than VFX Forth for my endgame program. I am now testing 64-bit iForth. Since it is still in alpha stage, there is still long way to go. I shall update the progress here.

8 comments:

Anonymous said...

hi,Pai:
我是meifire,我在研究兵类残局时在你的残局库里发现了一个错误.
http://lpforth.forthfreak.net/cgi-bin/endgame.cgi?4K43p1p33BE3E9999994k1e2
这是一个很明显的红胜残局,可残局库却认为是和棋?
甚至在帅五平四之后已经叫杀,仍然认为和棋
http://lpforth.forthfreak.net/cgi-bin/endgame.cgi?4K43p1p33BE3E9999995ke20
直到象5进3之后才看出红方兵四进一可胜,却又不推荐这一步
http://lpforth.forthfreak.net/cgi-bin/endgame.cgi?4K43p1p33B4E92E699995ke2
实在太奇怪了.是不是因为用了新的算法产生的bug?

Pai said...

I have replied you through e-mail. Didn't you receive it?

Anonymous said...

你好
這個局面是否有 bug?
http://lpforth.forthfreak.net/cgi-bin/endgame.cgi?4K43p1p33B4E92E699e4k399

Anonymous said...

原來有人貼了...

Anonymous said...

Reply to your post
Total endgames as of today (2007/11/19)
... While I am building more that I think are more interesting, I always welcome the suggestions. If you see some endgame missing that you really want to see, please leave a comment here. You will see it sooner. Please limit total attacking pieces under four.

knpbkpbbe or knpekpbbe seem interesting.
不久前我見過一局實戰,當時是紅勝了。
那局是 knpbbeekpbbe

Pai said...

Thanks for the suggestions. My computer is broken these days. Once I got it back, I will fix the bug as well as build the suggested ones. Thank you all.

Anonymous said...

thx very much

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