ALPAKA_ACCELERATOR_NAMESPACE::HGCalLayerClustersSoAAlgoKernelPositionByHits Class Reference

Public Member Functions
template<typename TAcc , typename = std::enable_if_t<alpaka::isAccelerator<TAcc>>>
ALPAKA_FN_ACC void	operator() (TAcc const &acc, const unsigned int numer_of_clusters, float thresholdW0, float positionDeltaRho2, const HGCalSoARecHitsDeviceCollection::ConstView input_rechits_soa, const HGCalSoARecHitsExtraDeviceCollection::ConstView input_clusters_soa, HGCalSoAClustersDeviceCollection::View outputs, HGCalSoAClustersExtraDeviceCollection::View outputs_service) const

Detailed Description

Definition at line 39 of file HGCalLayerClustersSoAAlgoWrapper.dev.cc.

Member Function Documentation

operator()()

template<typename TAcc , typename = std::enable_if_t<alpaka::isAccelerator<TAcc>>>

ALPAKA_FN_ACC void ALPAKA_ACCELERATOR_NAMESPACE::HGCalLayerClustersSoAAlgoKernelPositionByHits::operator() ( TAcc const &  acc, const unsigned int  numer_of_clusters, float  thresholdW0, float  positionDeltaRho2, const HGCalSoARecHitsDeviceCollection::ConstView  input_rechits_soa, const HGCalSoARecHitsExtraDeviceCollection::ConstView  input_clusters_soa, HGCalSoAClustersDeviceCollection::View  outputs, HGCalSoAClustersExtraDeviceCollection::View  outputs_service  ) const

inline

Definition at line 42 of file HGCalLayerClustersSoAAlgoWrapper.dev.cc.

References cms::cudacompat::atomicAdd(), f, hgcal::constants::kInvalidCluster, kInvalidIndex, fileCollector::seed, cms::alpakatools::uniform_elements(), and mps_merge::weight.

                                                                                                   {
      // make a strided loop over the kernel grid, covering up to "size" elements
      for (int32_t hit_index : uniform_elements(acc, input_rechits_soa.metadata().size())) {
        const int cluster_index = input_clusters_soa[hit_index].clusterIndex();

        // Bail out if you are not part of any cluster
        if (cluster_index == kInvalidCluster) {
          continue;
        }

        alpaka::atomicAdd(acc, &outputs_service[cluster_index].total_weight(), input_rechits_soa[hit_index].weight());
        // Read the current seed index, and the associated energy.
        int clusterSeed = outputs_service[cluster_index].maxEnergyIndex();
        float clusterEnergy = (clusterSeed == kInvalidIndex) ? 0.f : input_rechits_soa[clusterSeed].weight();

        while (input_rechits_soa[hit_index].weight() > clusterEnergy) {
          // If output_service[cluster_index].maxEnergyIndex() did not change,
          // store the new value and exit the loop.  Otherwise return the value
          // that has been updated, and decide again if the maximum needs to be
          // updated.
          int seed = alpaka::atomicCas(acc, &outputs_service[cluster_index].maxEnergyIndex(), clusterSeed, hit_index);
          if (seed == hit_index) {
            // atomicCas has stored the new value.
            break;
          } else {
            // Update the seed index and re-read the associated energy.
            clusterSeed = seed;
            clusterEnergy = (clusterSeed == kInvalidIndex) ? 0.f : input_rechits_soa[clusterSeed].weight();
          }
        }  // CAS
      }    // uniform_elements
    }      // operator()