Commit 9ddb7399 authored by Tomáš Oberhuber's avatar Tomáš Oberhuber
Browse files

Unrolling reduction in BiEllpack.

parent fc8cadec

src/TNL/Containers/Segments/BiEllpackView.hpp

+20 −3
Original line number Diff line number Diff line
@@ -565,7 +565,6 @@ segmentsReductionKernel( IndexType gridIdx, 
         IndexType groupEnd = sharedGroupPointers[ group + 1 ];

         if( groupEnd - groupBegin > 0 )

         {



               if( inWarpIdx < groupHeight )

               {

                  const IndexType groupWidth = ( groupEnd - groupBegin ) / groupHeight;
@@ -594,13 +593,31 @@ segmentsReductionKernel( IndexType gridIdx, 
               globalIdx += getWarpSize();

            }

            // TODO: reduction via templates

            IndexType bisection2 = getWarpSize();

            /*IndexType bisection2 = getWarpSize();

            for( IndexType i = 0; i < group; i++ )

            {

               bisection2 >>= 1;

               if( inWarpIdx < bisection2 )

                  temp[ threadIdx.x ] = reduction( temp[ threadIdx.x ], temp[ threadIdx.x + bisection2 ] );

            }

            }*/



            __syncwarp();

            if( group > 0 && inWarpIdx < 16 )

                  temp[ threadIdx.x ] = reduction( temp[ threadIdx.x ], temp[ threadIdx.x + 16 ] );

            __syncwarp();

            if( group > 1 && inWarpIdx < 8 )

                  temp[ threadIdx.x ] = reduction( temp[ threadIdx.x ], temp[ threadIdx.x + 8 ] );

            __syncwarp();

            if( group > 2 && inWarpIdx < 4 )

                  temp[ threadIdx.x ] = reduction( temp[ threadIdx.x ], temp[ threadIdx.x + 4 ] );

            __syncwarp();

            if( group > 3 && inWarpIdx < 2 )

                  temp[ threadIdx.x ] = reduction( temp[ threadIdx.x ], temp[ threadIdx.x + 2 ] );

            __syncwarp();

            if( group > 4 && inWarpIdx < 1 )

                  temp[ threadIdx.x ] = reduction( temp[ threadIdx.x ], temp[ threadIdx.x + 1 ] );

            __syncwarp();



            if( inWarpIdx < groupHeight )

               results[ threadIdx.x ] = reduction( results[ threadIdx.x ], temp[ threadIdx.x ] );

         }