[petsc-users] MatCreateSeqAIJWithArrays for GPU / cusparse

[Barry Smith]

> On Jan 5, 2023, at 3:42 PM, Jed Brown <jed at jedbrown.org> wrote:
> 
> Mark Adams <mfadams at lbl.gov> writes:
> 
>> Support of HIP and CUDA hardware together would be crazy, 
> 
> I don't think it's remotely crazy. libCEED supports both together and it's very convenient when testing on a development machine that has one of each brand GPU and simplifies binary distribution for us and every package that uses us. Every day I wish PETSc could build with both simultaneously, but everyone tells me it's silly.

  Not everyone at all; just a subset of everyone. Junchao is really the hold-out :-)

  I just don't care about "binary packages" :-); I think they are an archaic and bad way of thinking about code distribution (but yes the alternatives need lots of work to make them flawless, but I think that is where the work should go in the packaging world.)

   I go further and think one should be able to automatically use a CUDA vector on a HIP device as well, it is not hard in theory but requires thinking about how we handle classes and subclasses a little to make it straightforward; or perhaps Jacob has fixed that also?