[petsc-dev] Broken MatMatMult_MPIAIJ_MPIDense

[Zhang, Hong]

Barry :

   We would like avoid allocating a huge array for the matrix and then having the user place on top of it.

   In the new paradigm there could be options called on the resulting C of MatMatGetProduct() that would take effect before the C is fully formed to prevent the allocating and freeing for a huge array the same time as user array exists but with the current API we have for this release.
Allocation of C is done in the symbolic product, not GetProduct(). Petsc gets user's array before symbolic product, thus it will not allocate C array.
Hong


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