FDICPreconditioner.C

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#include "FDICPreconditioner.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
    defineTypeNameAndDebug(FDICPreconditioner, 0);

    lduMatrix::preconditioner::
        addsymMatrixConstructorToTable<FDICPreconditioner>
        addFDICPreconditionerSymMatrixConstructorToTable_;
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::FDICPreconditioner::FDICPreconditioner
(
    const lduMatrix::solver& sol,
    const dictionary&
)
:
    lduMatrix::preconditioner(sol),
    rD_(sol.matrix().diag()),
    rDuUpper_(sol.matrix().upper().size()),
    rDlUpper_(sol.matrix().upper().size())
{
    scalar* __restrict__ rDPtr = rD_.begin();
    scalar* __restrict__ rDuUpperPtr = rDuUpper_.begin();
    scalar* __restrict__ rDlUpperPtr = rDlUpper_.begin();

    const label* const __restrict__ uPtr =
        solver_.matrix().lduAddr().upperAddr().begin();
    const label* const __restrict__ lPtr =
        solver_.matrix().lduAddr().lowerAddr().begin();
    const scalar* const __restrict__ upperPtr =
        solver_.matrix().upper().begin();

    label nCells = rD_.size();
    label nFaces = solver_.matrix().upper().size();

    for (label face=0; face<nFaces; face++)
    {
        rDPtr[uPtr[face]] -= sqr(upperPtr[face])/rDPtr[lPtr[face]];
    }

    // Generate reciprocal FDIC
    for (label cell=0; cell<nCells; cell++)
    {
        rDPtr[cell] = 1.0/rDPtr[cell];
    }

    for (label face=0; face<nFaces; face++)
    {
        rDuUpperPtr[face] = rDPtr[uPtr[face]]*upperPtr[face];
        rDlUpperPtr[face] = rDPtr[lPtr[face]]*upperPtr[face];
    }
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void Foam::FDICPreconditioner::precondition
(
    scalarField& wA,
    const scalarField& rA,
    const direction
) const
{
    scalar* __restrict__ wAPtr = wA.begin();
    const scalar* __restrict__ rAPtr = rA.begin();
    const scalar* __restrict__ rDPtr = rD_.begin();

    const label* const __restrict__ uPtr =
        solver_.matrix().lduAddr().upperAddr().begin();
    const label* const __restrict__ lPtr =
        solver_.matrix().lduAddr().lowerAddr().begin();

    const scalar* const __restrict__ rDuUpperPtr = rDuUpper_.begin();
    const scalar* const __restrict__ rDlUpperPtr = rDlUpper_.begin();

    label nCells = wA.size();
    label nFaces = solver_.matrix().upper().size();
    label nFacesM1 = nFaces - 1;

    for (label cell=0; cell<nCells; cell++)
    {
        wAPtr[cell] = rDPtr[cell]*rAPtr[cell];
    }

    for (label face=0; face<nFaces; face++)
    {
        wAPtr[uPtr[face]] -= rDuUpperPtr[face]*wAPtr[lPtr[face]];
    }

    for (label face=nFacesM1; face>=0; face--)
    {
        wAPtr[lPtr[face]] -= rDlUpperPtr[face]*wAPtr[uPtr[face]];
    }
}


// ************************************************************************* //