Thyra_SpmdVectorSpaceUtilities.cpp

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// ***********************************************************************
// 
//    Thyra: Interfaces and Support for Abstract Numerical Algorithms
//                 Copyright (2004) Sandia Corporation
// 
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
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#include "Thyra_SpmdVectorSpaceUtilities.hpp"
#include "Teuchos_CommHelpers.hpp"

namespace Thyra {

Index SpmdVectorSpaceUtilities::computeMapCode(
  const Teuchos::Comm<Index> &comm, const Index localSubDim
  )
{
  //
  // Here we will make a map code out of just the local
  // sub-dimension on each processor.  If each processor
  // has the same number of local elements, then the maps
  // will be the same and this is all you need for
  // RTOp compatibility unless the operations are not
  // coordinate invariant.  I will work on this issue
  // if it becomes a problem.
  //
  const int procRank = size(comm);
  Index mapCode = -1;
  Index localCode = localSubDim % (procRank+1) + localSubDim;
  reduceAll(comm,Teuchos::REDUCE_SUM,localCode,&mapCode);
  return mapCode;
}

Index SpmdVectorSpaceUtilities::computeLocalOffset(
  const Teuchos::Comm<Index> &comm, const Index localSubDim
  )
{
  Index localOffset;
  Index _localOffset = localSubDim;
  scan(comm,Teuchos::REDUCE_SUM,_localOffset,&localOffset);
  localOffset -= localSubDim;
  return localOffset;
}

Index SpmdVectorSpaceUtilities::computeGlobalDim(
  const Teuchos::Comm<Index> &comm, const Index localSubDim
  )
{
  Index globalDim = -1;
  reduceAll(comm,Teuchos::REDUCE_SUM,localSubDim,&globalDim);
  return globalDim;
}

} // namespace Thyra

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