pairGAMGAgglomeration: Support reverse cell-scanning without reversing the order of the generated agglomeration

Gives better cache coherency
This commit is contained in:
Henry
2013-06-12 12:57:50 +01:00
parent 6b054eab14
commit 818f6a549f
3 changed files with 190 additions and 174 deletions

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@ -26,177 +26,7 @@ License
#include "pairGAMGAgglomeration.H"
#include "lduAddressing.H"
// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
Foam::tmp<Foam::labelField> Foam::pairGAMGAgglomeration::agglomerate
(
label& nCoarseCells,
const lduAddressing& fineMatrixAddressing,
const scalarField& faceWeights
)
{
const label nFineCells = fineMatrixAddressing.size();
const labelUList& upperAddr = fineMatrixAddressing.upperAddr();
const labelUList& lowerAddr = fineMatrixAddressing.lowerAddr();
// For each cell calculate faces
labelList cellFaces(upperAddr.size() + lowerAddr.size());
labelList cellFaceOffsets(nFineCells + 1);
// memory management
{
labelList nNbrs(nFineCells, 0);
forAll(upperAddr, facei)
{
nNbrs[upperAddr[facei]]++;
}
forAll(lowerAddr, facei)
{
nNbrs[lowerAddr[facei]]++;
}
cellFaceOffsets[0] = 0;
forAll(nNbrs, celli)
{
cellFaceOffsets[celli+1] = cellFaceOffsets[celli] + nNbrs[celli];
}
// reset the whole list to use as counter
nNbrs = 0;
forAll(upperAddr, facei)
{
cellFaces
[
cellFaceOffsets[upperAddr[facei]] + nNbrs[upperAddr[facei]]
] = facei;
nNbrs[upperAddr[facei]]++;
}
forAll(lowerAddr, facei)
{
cellFaces
[
cellFaceOffsets[lowerAddr[facei]] + nNbrs[lowerAddr[facei]]
] = facei;
nNbrs[lowerAddr[facei]]++;
}
}
// go through the faces and create clusters
tmp<labelField> tcoarseCellMap(new labelField(nFineCells, -1));
labelField& coarseCellMap = tcoarseCellMap();
nCoarseCells = 0;
for (label celli=0; celli<nFineCells; celli++)
{
if (coarseCellMap[celli] < 0)
{
label matchFaceNo = -1;
scalar maxFaceWeight = -GREAT;
// check faces to find ungrouped neighbour with largest face weight
for
(
label faceOs=cellFaceOffsets[celli];
faceOs<cellFaceOffsets[celli+1];
faceOs++
)
{
label facei = cellFaces[faceOs];
// I don't know whether the current cell is owner or neighbour.
// Therefore I'll check both sides
if
(
coarseCellMap[upperAddr[facei]] < 0
&& coarseCellMap[lowerAddr[facei]] < 0
&& faceWeights[facei] > maxFaceWeight
)
{
// Match found. Pick up all the necessary data
matchFaceNo = facei;
maxFaceWeight = faceWeights[facei];
}
}
if (matchFaceNo >= 0)
{
// Make a new group
coarseCellMap[upperAddr[matchFaceNo]] = nCoarseCells;
coarseCellMap[lowerAddr[matchFaceNo]] = nCoarseCells;
nCoarseCells++;
}
else
{
// No match. Find the best neighbouring cluster and
// put the cell there
label clusterMatchFaceNo = -1;
scalar clusterMaxFaceCoeff = -GREAT;
for
(
label faceOs=cellFaceOffsets[celli];
faceOs<cellFaceOffsets[celli+1];
faceOs++
)
{
label facei = cellFaces[faceOs];
if (faceWeights[facei] > clusterMaxFaceCoeff)
{
clusterMatchFaceNo = facei;
clusterMaxFaceCoeff = faceWeights[facei];
}
}
if (clusterMatchFaceNo >= 0)
{
// Add the cell to the best cluster
coarseCellMap[celli] = max
(
coarseCellMap[upperAddr[clusterMatchFaceNo]],
coarseCellMap[lowerAddr[clusterMatchFaceNo]]
);
}
}
}
}
// Check that all cells are part of clusters,
// if not create single-cell "clusters" for each
for (label celli=0; celli<nFineCells; celli++)
{
if (coarseCellMap[celli] < 0)
{
coarseCellMap[celli] = nCoarseCells;
nCoarseCells++;
}
}
// Reverse the map ordering to improve the next level of agglomeration
// (doesn't always help and is sometimes detrimental)
nCoarseCells--;
forAll(coarseCellMap, celli)
{
coarseCellMap[celli] = nCoarseCells - coarseCellMap[celli];
}
nCoarseCells++;
return tcoarseCellMap;
}
// * * * * * * * * * * * * * Protected Member Functions * * * * * * * * * * //
void Foam::pairGAMGAgglomeration::agglomerate
(
@ -285,4 +115,187 @@ void Foam::pairGAMGAgglomeration::agglomerate
}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
Foam::tmp<Foam::labelField> Foam::pairGAMGAgglomeration::agglomerate
(
label& nCoarseCells,
const lduAddressing& fineMatrixAddressing,
const scalarField& faceWeights
)
{
const label nFineCells = fineMatrixAddressing.size();
const labelUList& upperAddr = fineMatrixAddressing.upperAddr();
const labelUList& lowerAddr = fineMatrixAddressing.lowerAddr();
// For each cell calculate faces
labelList cellFaces(upperAddr.size() + lowerAddr.size());
labelList cellFaceOffsets(nFineCells + 1);
// memory management
{
labelList nNbrs(nFineCells, 0);
forAll(upperAddr, facei)
{
nNbrs[upperAddr[facei]]++;
}
forAll(lowerAddr, facei)
{
nNbrs[lowerAddr[facei]]++;
}
cellFaceOffsets[0] = 0;
forAll(nNbrs, celli)
{
cellFaceOffsets[celli+1] = cellFaceOffsets[celli] + nNbrs[celli];
}
// reset the whole list to use as counter
nNbrs = 0;
forAll(upperAddr, facei)
{
cellFaces
[
cellFaceOffsets[upperAddr[facei]] + nNbrs[upperAddr[facei]]
] = facei;
nNbrs[upperAddr[facei]]++;
}
forAll(lowerAddr, facei)
{
cellFaces
[
cellFaceOffsets[lowerAddr[facei]] + nNbrs[lowerAddr[facei]]
] = facei;
nNbrs[lowerAddr[facei]]++;
}
}
// go through the faces and create clusters
tmp<labelField> tcoarseCellMap(new labelField(nFineCells, -1));
labelField& coarseCellMap = tcoarseCellMap();
nCoarseCells = 0;
label celli;
for (label cellfi=0; cellfi<nFineCells; cellfi++)
{
// Change cell ordering depending on direction for this level
celli = forward_ ? cellfi : nFineCells - cellfi - 1;
if (coarseCellMap[celli] < 0)
{
label matchFaceNo = -1;
scalar maxFaceWeight = -GREAT;
// check faces to find ungrouped neighbour with largest face weight
for
(
label faceOs=cellFaceOffsets[celli];
faceOs<cellFaceOffsets[celli+1];
faceOs++
)
{
label facei = cellFaces[faceOs];
// I don't know whether the current cell is owner or neighbour.
// Therefore I'll check both sides
if
(
coarseCellMap[upperAddr[facei]] < 0
&& coarseCellMap[lowerAddr[facei]] < 0
&& faceWeights[facei] > maxFaceWeight
)
{
// Match found. Pick up all the necessary data
matchFaceNo = facei;
maxFaceWeight = faceWeights[facei];
}
}
if (matchFaceNo >= 0)
{
// Make a new group
coarseCellMap[upperAddr[matchFaceNo]] = nCoarseCells;
coarseCellMap[lowerAddr[matchFaceNo]] = nCoarseCells;
nCoarseCells++;
}
else
{
// No match. Find the best neighbouring cluster and
// put the cell there
label clusterMatchFaceNo = -1;
scalar clusterMaxFaceCoeff = -GREAT;
for
(
label faceOs=cellFaceOffsets[celli];
faceOs<cellFaceOffsets[celli+1];
faceOs++
)
{
label facei = cellFaces[faceOs];
if (faceWeights[facei] > clusterMaxFaceCoeff)
{
clusterMatchFaceNo = facei;
clusterMaxFaceCoeff = faceWeights[facei];
}
}
if (clusterMatchFaceNo >= 0)
{
// Add the cell to the best cluster
coarseCellMap[celli] = max
(
coarseCellMap[upperAddr[clusterMatchFaceNo]],
coarseCellMap[lowerAddr[clusterMatchFaceNo]]
);
}
}
}
}
// Check that all cells are part of clusters,
// if not create single-cell "clusters" for each
for (label cellfi=0; cellfi<nFineCells; cellfi++)
{
// Change cell ordering depending on direction for this level
celli = forward_ ? cellfi : nFineCells - cellfi - 1;
if (coarseCellMap[celli] < 0)
{
coarseCellMap[celli] = nCoarseCells;
nCoarseCells++;
}
}
if (!forward_)
{
nCoarseCells--;
forAll(coarseCellMap, celli)
{
coarseCellMap[celli] = nCoarseCells - coarseCellMap[celli];
}
nCoarseCells++;
}
// Reverse the map ordering for the next level
// to improve the next level of agglomeration
forward_ = !forward_;
return tcoarseCellMap;
}
// ************************************************************************* //

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@ -2,7 +2,7 @@
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2011-2012 OpenFOAM Foundation
\\ / A nd | Copyright (C) 2011-2013 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
@ -30,6 +30,7 @@ License
namespace Foam
{
defineTypeNameAndDebug(pairGAMGAgglomeration, 0);
bool pairGAMGAgglomeration::forward_(true);
}

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@ -56,6 +56,9 @@ class pairGAMGAgglomeration
//- Number of levels to merge, 1 = don't merge, 2 = merge pairs etc.
label mergeLevels_;
//- Direction of cell loop for the current level
static bool forward_;
protected:
@ -97,7 +100,6 @@ public:
const lduAddressing& fineMatrixAddressing,
const scalarField& faceWeights
);
};