Changes in dfg2llvm_nvptx pass.

- Simple (only for first cut, to be reconsidered) kernel selection.
- Code refactoring.

llvm/lib/Transforms/DFG2LLVM_NVPTX/DFG2LLVM_NVPTX.cpp

@@ -61,6 +61,7 @@ namespace {
     //Member variables
     Module &M;
     BuildDFG &DFG;
+    DFNode * KernelLaunchNode;
 
     // Map from Old function associated with DFNode to new cloned function with
     // extra index and dimension arguments. This map also serves to find out if
@@ -101,6 +102,18 @@ namespace {
 
   void CodeGenTraversal::codeGen(DFInternalNode* N) {
 
+    if (!KernelLaunchNode) {
+      DEBUG(errs() << "No code generated (host code for kernel launch complete).\n");
+      return;
+    }
+
+    if (N == KernelLaunchNode) {
+      DEBUG(errs() << "Found kernel launch node. Generating host code.\n");
+    } else {
+      DEBUG(errs() << "Found intermediate node. Generating device code.\n");
+      DEBUG(errs() << "Changing leaf node function to device function.\n");
+    }
+
   }
 
   void CodeGenTraversal::codeGen(DFLeafNode* N) {
@@ -111,6 +124,16 @@ namespace {
       return;
     }
 
+    // Checking which node is the kernel launch
+    DFNode* PNode = N->getParent();
+    int pLevel = PNode->getLevel();
+    int pReplFactor = PNode->getNumOfDim();
+
+    if (!pLevel || !pReplFactor)
+      KernelLaunchNode = PNode;
+    else
+      KernelLaunchNode = PNode->getParent();
+
     std::vector<IntrinsicInst *> IItoRemove;
     BuildDFG::HandleToDFNode Leaf_HandleToDFNodeMap;