On Saturday 23 July 2011 21:17:25 Jason wrote: > There's sandybridge addsub to do
The gain was extremely small so I won't bother > and that will finish the asm part of toom > evaluation for +-1 , I'll write the C bit , and then do the asm for > evaluation at +-2 +-1/2 +-4 etc , this will consist of inclsh's/incrsh's I'll get onto this now > and then perhaps do a toom23 interpolation combined with a reconstitution > if it seems worth while(karasub/add was the toom22 version of this). The above is complicated by the amount of different ways we can combine the two phases of the toom's interpolation and re-composition , definitely looks like it's worth doing , but it will have to wait for MPIR 2.6 as until I get all the basic asm fn's written there is no way you can know which way is best , previous mathematical analysis are no use because they only assume basic operations ie add,sub,shift and ignore the large savings of rsh1add,addsub etc and some strange ones ie dualsub . Note: combining these two phases and using specific fn's was key to karasub/add speed. > That > will be all for now on toom from me. Then I want to try to improve our > *_basecase's , that will probably all I get to do before our next release. I also want to improve the way I do the inner loops , at the moment I look for loops that have timings (over all alignments) < some limit , instead I think if I took the loop which has the least sum of timings over all alignments would give a faster average speed. Also I try to do an exhaustive search which is not really possible , find some way to overcome this , one thought is to use a genetic algorithm. > How's the FFT going? Let me know what linear asm stuff might be needed so > I can start thinking about it , even if I write no code. > > On Saturday 23 July 2011 18:25:57 Bill Hart wrote: > > There is a way in Ubuntu. It may be similar in Debian. However, I've > > forgotten what the command is and I think you need sudo powers. > > Possible skynet may be able to accommodate this if the kernel has the right > Capability handling in it , ie you can restrict a particular sudo to only > one aspect of the system. > > > Bill. > > > > On 23 July 2011 16:32, Jason <ja...@njkfrudils.plus.com> wrote: > > > On Saturday 23 July 2011 15:42:08 Jason wrote: > > >> On Saturday 23 July 2011 14:18:09 Jason wrote: > > >> > On Friday 22 July 2011 23:11:29 Jason wrote: > > >> > > On Friday 22 July 2011 17:39:55 Jason wrote: > > >> > > > On Friday 22 July 2011 12:36:21 Jason wrote: > > >> > > > > On Friday 22 July 2011 12:25:42 Bill Hart wrote: > > >> > > > > > That's fantastic! Thanks for all your hard work on these > > >> > > > > > Jason. > > >> > > > > > > > >> > > > > > Bill. > > >> > > > > > > > >> > > > > > On 22 July 2011 11:13, jason <ja...@njkfrudils.plus.com> wrote: > > >> > > > > > > Hi > > >> > > > > > > > > >> > > > > > > New assembler for the nehalem mpn_addadd mpn_addsub > > >> > > > > > > mpn_subadd , used to run at 3.5c/l now at 3.0c/l therefore > > >> > > > > > > optimal. I'll check out how they run on the other intel > > >> > > > > > > chips. > > >> > > > > > > >> > > > > it's also an improvement on core2/penryn and nearly optimal , > > >> > > > > probably just needs a shuffle. Sandybridge doesn't benefit > > >> > > > > though. > > >> > > > > > > >> > > > > > > Note mpn_subadd really should be called mpn_subsub , I'll > > >> > > > > > > change it later. > > >> > > > > > > > > >> > > > > > > Jason > > >> > > > > > > > > >> > > > > > > -- > > >> > > > > > > You received this message because you are subscribed to > > >> > > > > > > the Google Groups "mpir-devel" group. To post to this > > >> > > > > > > group, send email to mpir-devel@googlegroups.com. To > > >> > > > > > > unsubscribe from this group, send email to > > >> > > > > > > mpir-devel+unsubscr...@googlegroups.com. For more options, > > >> > > > > > > visit this group at > > >> > > > > > > http://groups.google.com/group/mpir-devel?hl=en. > > >> > > > > > >> > > > I tried to do a mpn_addaddadd ie x=y+z+u+v but on Intel chips > > >> > > > the scheduler cant really cope with it , also with 5 pointer > > >> > > > you get so many L1 data cache bank conflicts that the code runs > > >> > > > at different speeds for the relative differences between the > > >> > > > pointers mod 64 . But if we are many using it for toom then we > > >> > > > could perhaps guarantee the relative differences. On the AMD > > >> > > > chips I have a strange problem with my optimizer where it > > >> > > > reports silly numbers for some functions ie sumdiff addadd , no > > >> > > > idea why it's happening , I even reverted to an earier svn > > >> > > > version where I found the original fast addadd code , but it > > >> > > > still gave silly figures , but karaadd was fine ? > > >> > > > > > >> > > > Jason > > >> > > > > >> > > New mpn_sumdiff for the nehalem , didn't have before so we can say > > >> > > it would of run at 4.0c/w but now is 3.6c/w (lost a lttle bit with > > >> > > the feedin) , this code also benefits the core2 but not penryn or > > >> > > sandybridge , probably just another trivial shuffle needed :) > > >> > > > > >> > > Jason > > >> > > > >> > I've shuffled the sumdiff for the core2 it's a bit faster at 3.5c/w > > >> > > > >> > Jason > > >> > > >> I've shuffled the sumdiff again for penryn and it runs at 3.7c/w > > >> > > >> and for netburst/atom I'll just choose the fastest from what we > > >> already have (just before release) , the only one left to do is > > >> westmere on the gcc farm , I dont know how loaded it is , so I might > > >> not be able to make any meaningful comparisons. > > >> > > >> Jason > > > > > > Well gcc20 (westmere) is very lightly loaded at the moment but it has > > > Mhz throttling to save power and turbo boost ,which means I can't use > > > it for timings. Have to find a software way to temporary turn these > > > off , on my machines (nehalem,sandybridge,bobcat) I just turned it off > > > in the bios. > > > > > > Jason > > > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "mpir-devel" group. To post to this group, send email to > > > mpir-devel@googlegroups.com. To unsubscribe from this group, send email > > > to mpir-devel+unsubscr...@googlegroups.com. For more options, visit > > > this group at http://groups.google.com/group/mpir-devel?hl=en. -- You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to mpir-devel@googlegroups.com. To unsubscribe from this group, send email to mpir-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en.
