[petsc-users] Question -with-64-bit-blas-indices

[Randall Mackie]

With the release of PETSc 3.12, there is a new option mentioned in the list of changes:

Added --with-64-bit-blas-indices that will switch to 64 bit indices when using MKL libraries for BLAS/LAPACK and build OpenBLAS with this support

Is this option only for use when compiling PETSc with 64 bit indices and also using MKL?
We’ve used 64 bit PETSc in the past in conjunction with MKL and I”m curious what if anything has changed.

Thanks,

Randy M.