> El 21 abr 2020, a las 17:53, Pierre Jolivet <pierre.joli...@enseeiht.fr>
> escribió:
>
>
>
>> On 21 Apr 2020, at 5:22 PM, Zhang, Hong <hzh...@mcs.anl.gov> wrote:
>>
>> Pierre,
>> MatMatMult_xxx() is removed from MatOps table.
>
> Shouldn’t there be a deprecation notice somewhere?
> There is nothing about MATOP_MAT_MULT in the 3.13 changelog
> https://www.mcs.anl.gov/petsc/documentation/changes/313.html
> For example, I see that in SLEPc, José is currently making these checks,
> which are in practice useless as they always return PETSC_FALSE?
> https://gitlab.com/slepc/slepc/-/blob/master/src/sys/classes/bv/impls/contiguous/contig.c#L191
> (Maybe José is aware of this and this is just for testing)
No, I was not aware of this. Thanks for bringing this up. Now in 3.13 we are
always doing the slow version (column by column), so yes I am interested in a
solution for this.
>
>> MatMatMult() is replaced by
>> MatProductCreate()
>> MatProductSetType(,MATPRODUCT_AB)
>> MatProductSetFromOptions()
>> MatProductSymbolic()
>> MatProductNumeric()
>>
>> Where/when do you need query a single matrix for its product operation?
>
> I didn’t want to bother at first with the new API, because I’m only
> interested in C = A*B with C and B being dense.
> Of course, I can update my code, but if I understand Stefano’s issue
> correctly, and let’s say my A is of type SBAIJ, for which there is no
> MatMatMult, the code will now error out in the MatProduct?
> There is no fallback mechanism? Meaning I could in fact _not_ use the new API
> and will just have to loop on all columns of B, even for AIJ matrices.
>
> Thanks,
> Pierre
>
>> Hong
>>
>> From: petsc-dev <petsc-dev-boun...@mcs.anl.gov> on behalf of Pierre Jolivet
>> <pierre.joli...@enseeiht.fr>
>> Sent: Tuesday, April 21, 2020 7:50 AM
>> To: petsc-dev <petsc-dev@mcs.anl.gov>
>> Subject: [petsc-dev] MATOP_MAT_MULT
>>
>> Hello,
>> Am I seeing this correctly?
>> #include <petsc.h>
>>
>> int main(int argc,char **args)
>> {
>> Mat A;
>> PetscBool hasMatMult;
>> PetscErrorCode ierr;
>>
>> ierr = PetscInitialize(&argc,&args,NULL,NULL);if (ierr) return ierr;
>> ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
>> ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
>> ierr = MatHasOperation(A,MATOP_MAT_MULT,&hasMatMult);CHKERRQ(ierr);
>> printf("%s\n", PetscBools[hasMatMult]);
>> ierr = PetscFinalize();
>> return ierr;
>> }
>>
>> => FALSE
>>
>> I believe this is a regression (or at least an undocumented change)
>> introduced here: https://gitlab.com/petsc/petsc/-/merge_requests/2524/
>> I also believe Stefano raised a similar point there:
>> https://gitlab.com/petsc/petsc/-/issues/608
>> This is a performance killer in my case because I was previously using this
>> check to know whether I could use MatMatMult or had to loop on all columns
>> and call MatMult on all of them.
>> There is also a bunch of (previously functioning but now) broken code, e.g.,
>> https://www.mcs.anl.gov/petsc/petsc-current/src/mat/impls/transpose/transm.c.html#line105
>> or
>> https://www.mcs.anl.gov/petsc/petsc-current/src/mat/impls/nest/matnest.c.html#line2105
>> Is this being addressed/documented?
>>
>> Thanks,
>> Pierre
>
