ops: tpetra-block: revise matrix-matrix product

[mzuzek]

@fnrizzi

refs #451

Contents

• [x] review overload constraints
• [x] add missing unit tests for existing overloads
• [x] refactor unit test fixtures
• [x] list overloads and test cases

Overloads

Tpetra-block level-3 pressio::ops::product() (i.e. performing C = alpha * op(A) * op(B) + beta * C) overloads:

A	B	C	op(A)	op(B)
tpetra MV-block	tpetra MV-block	eigen col-major matrix	transpose	nontranspose
tpetra MV-block	tpetra MV-block	dynamic eigen matrix (returned value)	transpose	nontranspose
tpetra MV-block	⨯ (self product)	eigen matrix	transpose	nontranspose
tpetra MV-block	⨯ (self product)	dynamic eigen matrix (returned value)	transpose	nontranspose
tpetra MV-block	⨯ (self product)	kokkos dense matrix	transpose	nontranspose
tpetra MV-block	⨯ (self product)	dynamic kokkos dense matrix (returned value)	transpose	nontranspose
tpetra MV-block	tpetra MV-block	kokkos dense matrix	transpose	nontranspose

Test coverage

Test cases for Tpetra-block level-3 implementations of pressio::ops::product() (op(A) is always transpose and op(B) is always nontranspose):

test	A	B	C
mv_T_mv_storein_eigen_C	Tpetra::BlockMultiVector	Tpetra::BlockMultiVector	Eigen::MatrixXd
mv_T_self_storein_eigen_C	Tpetra::BlockMultiVector	⨯	Eigen::MatrixXd
mv_T_self_create_result_eigen_C mv_T_self_storein_eigen_C_beta0	Tpetra::BlockMultiVector	Tpetra::BlockMultiVector	Eigen::MatrixXd
mv_T_self_storein_kokkos_C mv_T_self_storein_kokkos_C_beta0	Tpetra::BlockMultiVector	⨯	Kokkos::View<double**, Kokkos::LayoutLeft>
mv_T_mv_storein_kokkos_C mv_T_mv_storein_kokkos_C_beta0	Tpetra::BlockMultiVector	Tpetra::BlockMultiVector	Kokkos::View<double**, Kokkos::LayoutLeft>

[mzuzek]

thanks @fnrizzi for your review!