Re: Matrix multiplication performance
Michael Lehn <[email protected]>
| Newsgroups | gmane.comp.lib.boost.ublas |
|---|---|
| Message-ID | <[email protected]> |
Oh noo, grr. Yes you are right. Sorry, the stuff gets generated automatically and it again copied "fma.hpp" form the wrong server/directory. Could you check again: http://www.mathematik.uni-ulm.de/~lehn/test_ublas/fma.hpp The kernel requires MR=4 and NR=12 and uses the vfmadd231pd instruction Quoting palik imre <[email protected]>: > Are you sure about the replacement? this fma.hpp is practically > identical with your avx.hpp > > > On Friday, 29 January 2016, 0:21, Michael Lehn > <[email protected]> wrote: > > > Could you also compile with -DHAVE_FMA? However, I noticed that I > messed up the file ?fma.hpp? whenI created the page. So you should > replace it with > http://www.mathematik.uni-ulm.de/~lehn/test_ublas/fma.hpp > At the moment I regenerate the pages on the website > > > On 28 Jan 2016, at 18:08, palik imre <[email protected]> wrote: > > Wow: > $ cd session4 > $ g++ -Ofast -mavx -Wall -std=c++11 -DNDEBUG -DHAVE_AVX -fopenmp > -DM_MAX=1500 matprod.cc > matprod.cc: In function ???double estimateGemmResidual(const MA&, > const MB&, const MC0&, const MC1&)???: > matprod.cc:94:40: warning: typedef ???TC0??? locally defined but not > used [-Wunused-local-typedefs] > typedef typename MC0::value_type TC0; > ^ > $ ./a.out > # m n k uBLAS: t1 MFLOPS Blocked: t2 > MFLOPS Diff nrm1 > 100 100 100 0.000465896 4292.8 0.00405376 > 493.369 200 200 200 0.0046712 > 3425.24 0.00244891 6533.51 300 300 > 300 0.0161551 3342.59 0.00314843 17151.4 > 1.94151e-16 > 400 400 400 0.032688 3915.81 0.00240584 > 53204 8.40477e-17 > 500 500 500 0.0544033 4595.31 0.00291218 > 85846.4 3.52062e-17 > 600 600 600 0.0838317 5153.18 0.00453539 > 95250.9 1.63452e-17 > 700 700 700 0.130899 5240.69 0.00585201 > 117225 8.44769e-18 > 800 800 800 0.201121 5091.46 0.010872 > 94186.5 4.72429e-18 > 900 900 900 0.286407 5090.65 0.0151735 > 96088.7 2.80443e-18 > 1000 1000 1000 0.432211 4627.37 0.0707567 > 28265.9 1.7626e-18 > 1100 1100 1100 0.511146 5207.9 0.0186911 > 142420 1.14521e-18 > 1200 1200 1200 0.666975 5181.6 0.025109 > 137640 7.79963e-19 > 1300 1300 1300 0.863769 5087.01 0.0283398 > 155047 5.45468e-19 > 1400 1400 1400 1.09638 5005.57 0.143209 > 38321.6 3.90302e-19 > 1500 1500 1500 1.40352 4809.33 0.120096 > 56204.9 2.8667e-19 > $ cd ../session2 > $ g++ -Ofast -mavx -Wall -std=c++11 -DNDEBUG -DHAVE_AVX -fopenmp > -DM_MAX=1500 matprod.cc > [ec2-user@ip-10-0-46-255 session2]$ ./a.out > # m n k uBLAS: t1 MFLOPS Blocked: t2 > MFLOPS Diff nrm1 > 100 100 100 0.000471888 4238.29 0.000231317 > 8646.14 200 200 200 0.00431625 > 3706.92 0.00121122 13209.9 300 300 > 300 0.0153292 3522.69 0.00336464 16049.3 > 1.07937e-06 > 400 400 400 0.0317138 4036.1 0.00712568 > 17963.2 4.06488e-06 > 500 500 500 0.052809 4734.04 0.0121626 > 20554.9 9.09947e-06 > 600 600 600 0.0828121 5216.63 0.020657 > 20913 1.65243e-05 > 700 700 700 0.131053 5234.51 0.0318276 > 21553.6 2.71365e-05 > 800 800 800 0.196825 5202.58 0.0482679 > 21214.9 4.12109e-05 > 900 900 900 0.281006 5188.51 0.0671323 > 21718.3 5.93971e-05 > 1000 1000 1000 0.386332 5176.89 0.0906054 > 22073.7 8.23438e-05 > 1100 1100 1100 0.51667 5152.22 0.124346 > 21408.1 0.000109566 > 1200 1200 1200 0.668425 5170.37 0.159701 > 21640.5 0.000142817 > 1300 1300 1300 0.860445 5106.66 0.203472 > 21595.1 0.000182219 > 1400 1400 1400 1.08691 5049.18 0.249427 > 22002.4 0.000226999 > 1500 1500 1500 1.38244 4882.67 0.307519 > 21949.9 0.000280338 > > This is on Haswell > > > On Wednesday, 27 January 2016, 1:39, Michael Lehn > <[email protected]> wrote: > > > > On 23 Jan 2016, at 18:53, palik imre <[email protected]> wrote: > > Hi All, > what's next? I mean what is the development process for ublas? > Now we have a C-like implementation that outperforms both the > mainline, and the branch version (axpy_prod). What will we do with > that? > As far as I see we have the following options: > 1) Create a C++ template magic implementation out of it. But for > this, at the least we would need compile-time access to the target > instruction set. Any idea how to do that? > 2) Create a compiled library implementation out of it, and choose > the implementation run-time based on the CPU capabilities. > > 3) Include some good defaults/defines, and hope the user will use them. > 4) Don't include it, and do something completely different. > > > What do you think? > > > At the moment I am not sure, but pretty sure, that you don?t have to > rewrite uBLAS to support good performance. uBLAS is a pretty > finelibrary and already has what you need. So just extend it. At > least for 383 lines of code :-) > As I was pretty busy the last days, so I could not continue until > today. I made some minimal modifications to adopt the GEMM > implementationto take advantage of uBLAS: > - The GEMM frame algorithm and the pack functions now work with any > uBLAS matrix that supports element access through the notation > A(i,j)- Only for matrix C in the operation C <- beta*C + alpha*A*B > it requires that the matrix is stored row-major or col-major. The > other matrices canbe expressions. Here I need some help to get rid > of this ugly lines of code: > TC *C_ = &C(0,0); const size_type incRowC = &C(1,0) - > &C(0,0); const size_type incColC = &C(0,1) - &C(0,0); > - Things like the following should work without performance penalty > (and in particularly without creating temporaries): > blas::axpy_prod(3*A1+A2, B1 - B2, C, matprodUpdate) - And matrices > A and B can be symmetric or whatever. Of course if A or B is > triangular a specialized implementation can take advantage- The > storage format does not matter. You can mix row-major and > col-major, packed, ? > Here is the page for this: > http://www.mathematik.uni-ulm.de/~lehn/test_ublas/session4/page01.html > Please note, creating the benchmarks for the symmetric matrix-matrix > product really takes long because the current uBLAS implementation > seemsto be much slower than for general matrices. So I reduced the > problem size for now. It would be helpful if some people could > reproduce the benchmarksand also check different cases: > - different expressions- different element types, e.g. A with > floats, B with double etc. At the moment there is only a micro > kernel for double. The performance depends on thecommon type of A > and B. So with complex<..> the reference implementation. But the > performance should at least be constant in this case. > It would in particular be nice to have benchmarks from people with > an Intel Sandybridge or Haswell as the micro kernels are optimized > for thesearchitectures. If interested I can extend the benchmarks > to compare with Intel MKL. For Linux there is a free > non-commercial version available. > > Cheers, > Michael > > > > > > > > > > >