vas on subject of rybka -fruit requests a summariser

[duncan]

perhaps to make thinks easier for vas the summariser could post on rybka site

http://rybkaforum.net/cgi-bin/rybkaforu ... l?tid=6772

Please could you comment on this thread as some people are inferring things from your silence

http://64.68.157.89/forum/viewtopic.php ... _view=flat

The interesting thing that I found is that for this piece of code, Rybka 1.0 is more similar to Fruit than Strelka. Here are the differences:
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By Vempele Date 2008-08-25 11:17 Nah, it'd take him ages to wade through all the crap. This thread should be better. Ever try taking a screenshot of a beep?
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By Vasik Rajlich Date 2008-08-25 12:29 This discussion looks like a complete mess, I see wild statements like:


> --I noted earlier that the history initialization was different. Strelka and Rybka 1.0 are the same here, using memset(History, 256, 12 * 64 * sizeof(int)); But what I didn't notice is, 256 is out of range for an unsigned char. So that code is the same as Fruit's memset(History, 0, 12 * 64 * sizeof(int)); Why would Rybka 1.0 have 256? Is it the optimizer gone wild, or a deliberate attempt at obfuscation?


Maybe somebody can summarize the points.

Generally, code theft is easy to show - just show the two sections of identical code, side-by-side. There isn't much to debate in such cases. Rybka is of course original (with some accepted exceptions like bit scans & bit counters, etc). Strelka contains Rybka code. Whether Strelka also contains Fruit code, I don't know and don't really care.

Re. algorithms and structures - sure, you'll get a lot of similarity between programs. Take something like "modern move ordering" - by this, I mean hash move, non-losing captures (by MVV/LVA), killers, non-captures, and losing captures. The chance of two programmers settling on this independently is more or less zero.

Vas