Add conditional to copyEdgeNodes for reduced comm

src/gpu/VirtualFluids_GPU/Communication/ExchangeData27.cpp

@@ -250,7 +250,12 @@ void exchangeCollDataYGPU27(Parameter *para, vf::gpu::Communicator *comm, CudaMe
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     // edge nodes: copy received node values from x
     if (para->getUseStreams() && para->getNumberOfProcessNeighborsX(level, "recv") > 0) {
-        copyEdgeNodes(para->getParH(level)->edgeNodesXtoY, para->getParH(level)->recvProcessNeighborX, *sendProcessNeighborHost);
+        if(para->getParH(level)->sendProcessNeighborY[0].numberOfNodes == (*sendProcessNeighborHost)[0].numberOfNodes){ 
+            // check if in communication of all nodes (as opposed to reduced communication after fine to coarse)
+            copyEdgeNodes(para->getParH(level)->edgeNodesXtoY, para->getParH(level)->recvProcessNeighborX, *sendProcessNeighborHost);
+        } else{
+            copyEdgeNodes(para->getParH(level)->edgeNodesXtoY, para->getParH(level)->recvProcessNeighborsAfterFtoCX, *sendProcessNeighborHost);
+        }
     }
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     startBlockingMpiSend((unsigned int)(*sendProcessNeighborHost).size(), comm, sendProcessNeighborHost);
@@ -338,12 +343,22 @@ void exchangeCollDataZGPU27(Parameter *para, vf::gpu::Communicator *comm, CudaMe
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     // edge nodes: copy received node values from x
     if (para->getUseStreams() && para->getNumberOfProcessNeighborsX(level, "recv") > 0) {
-        copyEdgeNodes(para->getParH(level)->edgeNodesXtoZ, para->getParH(level)->recvProcessNeighborX, *sendProcessNeighborHost);
+        if(para->getParH(level)->sendProcessNeighborZ[0].numberOfNodes == (*sendProcessNeighborHost)[0].numberOfNodes){
+             // check if in communication of all nodes (as opposed to reduced communication after fine to coarse)
+            copyEdgeNodes(para->getParH(level)->edgeNodesXtoZ, para->getParH(level)->recvProcessNeighborX, *sendProcessNeighborHost);
+        } else{
+            copyEdgeNodes(para->getParH(level)->edgeNodesXtoZ, para->getParH(level)->recvProcessNeighborsAfterFtoCX, *sendProcessNeighborHost);
+        }
     }
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     // edge nodes: copy received node values from y
     if (para->getUseStreams() && para->getNumberOfProcessNeighborsY(level, "recv") > 0) {
-        copyEdgeNodes(para->getParH(level)->edgeNodesYtoZ, para->getParH(level)->recvProcessNeighborY, *sendProcessNeighborHost);
+        if(para->getParH(level)->sendProcessNeighborZ[0].numberOfNodes == (*sendProcessNeighborHost)[0].numberOfNodes){ 
+            // check if in communication of all nodes (as opposed to reduced communication after fine to coarse)
+            copyEdgeNodes(para->getParH(level)->edgeNodesYtoZ, para->getParH(level)->recvProcessNeighborY, *sendProcessNeighborHost);
+        } else{
+            copyEdgeNodes(para->getParH(level)->edgeNodesYtoZ, para->getParH(level)->recvProcessNeighborsAfterFtoCY, *sendProcessNeighborHost);
+        }
     }
     /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     startBlockingMpiSend((unsigned int)(*sendProcessNeighborHost).size(), comm, sendProcessNeighborHost);