xref: /petsc/src/mat/impls/aij/seq/crl/ftn-kernels/fmultcrl.F90 (revision edb0e59d3c097acd4a4005a4e51d4daa5c739255)
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3c96caaccSSatish Balay!    Fortran kernel for sparse matrix-vector product in the AIJ/CRL format
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5c96caaccSSatish Balay#include <petsc/finclude/petscsys.h>
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70ccf82acSMartin Diehlpure subroutine FortranMultCRL(m, rmax, x, y, icols, acols)
8*fe66ebccSMartin Diehl  use, intrinsic :: ISO_C_binding
90ccf82acSMartin Diehl  implicit none(type, external)
100ccf82acSMartin Diehl  PetscInt, intent(in) :: m, rmax, icols(m, rmax)
110ccf82acSMartin Diehl  PetscScalar, intent(in) :: x(0:m - 1), acols(m, rmax)
120ccf82acSMartin Diehl  PetscScalar, intent(out) :: y(m)
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14d66e387eSMartin Diehl  PetscInt :: i
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16d66e387eSMartin Diehl  y(1:m) = acols(1:m, 1)*x(icols(1:m, 1))
170113e719SMartin Diehl  do i = 2, rmax
18d66e387eSMartin Diehl    y(1:m) = y(1:m) + acols(1:m, i)*x(icols(1:m, i))
190113e719SMartin Diehl  end do
200113e719SMartin Diehlend subroutine FortranMultCRL
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