gaussReduce()

void F4Res::gaussReduce ( )

private

Definition at line 579 of file res-f4.cpp.

{
  bool onlyConstantMaps = false;
  std::vector<bool> track(mReducers.size());
 
  if (onlyConstantMaps)  // and not exterior algebra?
    {
      for (auto i = 0; i < mReducers.size(); i++)
        {
          track[i] = monoid().is_divisible_by_var_in_range(
              mReducers[i].mLeadTerm,
              monoid().n_vars() - mThisLevel + 1,
              monoid().n_vars() - 1);
        }
    }
 
#if defined(WITH_TBB)
  //std::cout << "about to do parallel gauss_reduce" << std::endl;
  using threadLocalDense_t = mtbb::enumerable_thread_specific<ElementArray>;
  // create a dense array for each thread
  threadLocalDense_t threadLocalDense([&]() { 
    return mRing.vectorArithmetic().allocateElementArray(static_cast<ComponentIndex>(mColumns.size()));
  });
  
  // Reduce to zero every spair. Recording creates the
  // corresponding syzygy, which is auto-reduced and correctly ordered.
 
  //  std::cout << "gauss_row: " << (gauss_row.isNull() ? "null" : "not-null")
  //  << std::endl;
  //  std::cout << "gauss_row size: " << mRing.vectorArithmetic().size(gauss_row) <<
  //  std::endl;
 
  //size_t chunk_size = std::max(mSPairs.size() / (100*mFrame.getNumThreads()), (size_t) 1);
  //mFrame.getScheduler().execute([this,&chunk_size,&onlyConstantMaps,&track,&threadLocalDense] {
  mFrame.getScheduler().execute([this,&onlyConstantMaps,&track,&threadLocalDense] {
  //mtbb::parallel_for(mtbb::blocked_range<int>{0,(int)mSPairs.size(),chunk_size},
  mtbb::parallel_for(mtbb::blocked_range<int>{0,(int)mSPairs.size()},
                    [&](const mtbb::blocked_range<int>& r)
                    {
                      //std::cout << "gauss reduce, " << r.begin() << "..<" << r.end() << " total: " << mSPairs.size() << std::endl;
                      threadLocalDense_t::reference my_dense = threadLocalDense.local();
                      for (auto i = r.begin(); i != r.end(); ++i) {
                        gaussReduceRow(i, my_dense, onlyConstantMaps, track);
                      }
                    });
  });
 
  for (auto tlDense : threadLocalDense)
    mRing.vectorArithmetic().deallocateElementArray(tlDense);
#else  
  // allocate a dense row, of correct size
  ElementArray gauss_row = mRing.vectorArithmetic().allocateElementArray(
      static_cast<ComponentIndex>(mColumns.size()));
  for (long i = 0; i < mSPairs.size(); i++)
    {
      gaussReduceRow(i, gauss_row, onlyConstantMaps, track);
    }
  mRing.vectorArithmetic().deallocateElementArray(gauss_row);
#endif  
}

References gaussReduceRow(), ResMonoidDense::is_divisible_by_var_in_range(), mColumns, mFrame, monoid(), mReducers, mRing, mSPairs, and mThisLevel.

Referenced by construct().