> 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 <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 <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) > 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/ > <https://gitlab.com/petsc/petsc/-/merge_requests/2524/> > I also believe Stefano raised a similar point there: > https://gitlab.com/petsc/petsc/-/issues/608 > <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 > > <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 > > <https://www.mcs.anl.gov/petsc/petsc-current/src/mat/impls/nest/matnest.c.html#line2105> > Is this being addressed/documented? > > Thanks, > Pierre