Faster GPU-ECM with CGBN

[chris2be8]

Originally Posted by EdH

I am confused (yet, again). How do I start from scratch to compile GMP-ECM with CGBN for an sm_35 card?

I would try:
mkdir ecm-gpu # Change dir name if you want
cd ecm-gpu
git clone https://gitlab.inria.fr/zimmerma/ecm.git
cd ecm
autoreconf -si
./configure --enable-gpu=35 -with-cgbn-include=/home/chris/ecm-seth/CGBN/include/cgbn # Update path to CGBN as appropriate
make

But I can't test it because I don't have a sm_35 GPU.

[EdH]

I guess my problem is getting CGBN. I'd already done the rest, but when I tried to get CGBN I got a "forbidden" message.

I thought the post from Gimarel meant that CGBN was included with GMP-ECM at that location.

I'll study the thread further. . .

[SethTro]

"Getting" CGBN should be `git clone https://github.com/NVlabs/CGBN.git` which will create a new directory "CGBN" then the commands chris2be8 wrote (thanks) should work.

I got access to contribute back to gmp-ecm so I will work on adding support for sm_86.

@chris2be8. I think you have an old version of the code. That limit was removed at some point. Can you check that you are using https://gitlab.inria.fr/zimmerma/ecm.git and not my personal repository (https://github.com/sethtroisi/gmp-ecm).

[EdH]

Originally Posted by SethTro

"Getting" CGBN should be `git clone https://github.com/NVlabs/CGBN.git` which will create a new directory "CGBN" then the commands chris2be8 wrote (thanks) should work.

I got access to contribute back to gmp-ecm so I will work on adding support for sm_86.

@chris2be8. I think you have an old version of the code. That limit was removed at some point. Can you check that you are using https://gitlab.inria.fr/zimmerma/ecm.git and not my personal repository (https://github.com/sethtroisi/gmp-ecm).

OK, Thanks! I think I'm getting somewhere. I found CGBN, but had trouble with googletest when unzip crashed with mismatched internal names. (Maybe I have an old CGBN?) I think I've worked around that now and am trying to compile CGBN, but it looks like it's stuck.

I think I'm where I can work it a little further. I'll get back in a bit.

[EdH]

Well, this isn't making any sense to me:

configure: Using CGBN from /home/math55/Math/CGBN/include/cgbn
checking if CGBN is present... no
configure: error: cgbn.h not found (check if /cgbn needed after <PATH>/include)

$ ls /home/math55/Math/CGBN/include/cgbn
arith       cgbn.cu      cgbn.h      core          impl_mpz.cc
cgbn_cpu.h  cgbn_cuda.h  cgbn_mpz.h  impl_cuda.cu

I even copied the directory from the properties for the cgbn.h file. I also tried with and without "/cgbn."

[EdH]

I think I found it. (from acinclude.m4):

            NVCC_CHECK_COMPILE(
              [
                #include <gmp.h>
                #include <cgbn.h>
              ],
              [-I$cgbn_include $GMPLIB],
              [AC_MSG_RESULT([yes])],
              [
                AC_MSG_RESULT([no])
                AC_MSG_ERROR([cgbn.h not found (check if /cgbn needed after <PATH>/include)])
              ]
             )

My ECM compile normally includes --with-gmp=/usr/local/, but I removed it for this ./configure and it finished without troubles.

I'm running it now and it appears to be doing OK.

Thanks for all the help.

[SethTro]

Originally Posted by EdH

OK, Thanks! I think I'm getting somewhere. I found CGBN, but had trouble with googletest when unzip crashed with mismatched internal names. (Maybe I have an old CGBN?) I think I've worked around that now and am trying to compile CGBN, but it looks like it's stuck.

I think I'm where I can work it a little further. I'll get back in a bit.

IFAIK you don't need to compile CGBN (or setup the googletest), you just need the folder downloaded ("cloned") from Github.

[EdH]

Originally Posted by SethTro

IFAIK you don't need to compile CGBN (or setup the googletest), you just need the folder downloaded ("cloned") from Github.

ATM, I have it running, but now that I've had success, I may backtrack to see if that is the case. Sorry if I've been too ignorant of all these workings, but I hope I'm learning something.

Thanks for all the help!

[EdH]

Originally Posted by SethTro

IFAIK you don't need to compile CGBN (or setup the googletest), you just need the folder downloaded ("cloned") from Github.

I restarted from scratch and now that I'm familiar with it, all went quick and easy.

[RichD]

Originally Posted by EdH

I restarted from scratch and now that I'm familiar with it, all went quick and easy.

Oh good, does that mean we might see a new "How I ... " thread?

[EdH]

Originally Posted by RichD

Oh good, does that mean we might see a new "How I ... " thread?

I wasn't considering one, since it really boils down to only a couple lines of install. Or, maybe you mean a GMP-ECM with GPU thread from start to finish? I do wonder if I should try to add CGBN to the Colab GMP-ECM session.