Author: James Swafford
Date: 12:44:07 05/30/04
Go up one level in this thread
On May 30, 2004 at 07:54:29, Sune Fischer wrote: >On May 30, 2004 at 07:17:01, James Swafford wrote: > >>On May 30, 2004 at 03:36:59, Sune Fischer wrote: >> >>>On May 29, 2004 at 22:53:38, James Swafford wrote: >>> >>>>On May 29, 2004 at 16:09:22, Sune Fischer wrote: >>>> >>>>>On May 29, 2004 at 14:41:28, Anthony Cozzie wrote: >>>>> >>>>>>On May 29, 2004 at 14:26:55, Russell Reagan wrote: >>>>>> >>>>>>>On May 29, 2004 at 04:24:18, Tony Werten wrote: >>>>>>> >>>>>>>>Yes, you would have to hop to nextsquare to see how it would go from there. Now >>>>>>>>you only have to look what square we are talking about, and if !nil, you will >>>>>>>>always know that the nextsquare will be given at *sq++ >>>>>>>> >>>>>>>>So you basicly made "nextsq" and "location of nextsq" independant of each other, >>>>>>>>thereby making it independant of board representation and making it more >>>>>>>>efficient since you will be traveling through the array in a row, rather than >>>>>>>>randomly accesed. >>>>>>> >>>>>>>Would this be any faster than a traditional array based move generator? As far >>>>>>>as I can tell, the array based movegen will iterate over an array, while the >>>>>>>move table approach loops over a linked list (effectively). Looping over an >>>>>>>array will almost always be at least as fast as looping through a linked list, >>>>>>>right? Plus the move table approach uses more memory to accomplish the same >>>>>>>thing. You may get some other advantages from a move table approach, but with >>>>>>>regard to speed, the move table approach doesn't seem like it would be the >>>>>>>fastest. >>>>>> >>>>>>The magic of Vincent's generator is that there are almost no branches and >>>>>>relatively little memory. The two biggest wastes of time in a modern deeply >>>>>>pipelined superscalar processor are branch mispredictions and cache misses. >>>>>> >>>>>>anthony >>>>> >>>>>I really don't understand all the hype about a generator. >>>>>I just had a look at a profile, mine spends something like 5% generating moves. >>>>>That's hardly worth even looking at to optimize. >>>>> >>>>>It might be due to its incremental design that it's so fast though ;) >>>>> >>>>>Sorting the moves however, now that takes time. >>>> >>>>What type of sort do you use? How often do you sort your >>>>move list(s)? >>> >>>I use SEE for the most part, expensive but seems to be well worth it. >> >>SEE scores moves, it doesn't sort: > >Assigning scores is the first step in the sorting process. > >>do you use (1)bubble sort, >>(2)quick sort, (3) no sort (scan for best) .. ? > >Depends on which is the fastest. :) Well, that's an interesting question! The magic "number" for sorting is to do it in O(n lg n), but I've heard others (I think Hyatt) use bubble sort, which has a running time of n^2. I'm using a stupid bubble sort, but I don't sort very often, and I plan on trying others at some point. > >-S. > >>-- >>James >> >> >>> >>>-S.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.