Enhance the GraphWriter support for edge destinations, and teach the

SelectionDAG graph writer to make use of them. Now, nodes with multiple
values are displayed as such, with incoming edges pointing to the
specific value they use.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53875 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/DOTGraphTraits.h

@@ -100,6 +100,24 @@ struct DefaultDOTGraphTraits {
     return I;
   }
 
+  /// hasEdgeDestLabels - If this function returns true, the graph is able
+  /// to provide labels for edge destinations.
+  static bool hasEdgeDestLabels() {
+    return false;
+  }
+
+  /// numEdgeDestLabels - If hasEdgeDestLabels, this function returns the
+  /// number of incoming edge labels the given node has.
+  static unsigned numEdgeDestLabels(const void *Node) {
+    return 0;
+  }
+
+  /// getEdgeDestLabel - If hasEdgeDestLabels, this function returns the
+  /// incoming edge label with the given index in the given node.
+  static std::string getEdgeDestLabel(const void *Node, unsigned i) {
+    return "";
+  }
+
   /// addCustomGraphFeatures - If a graph is made up of more than just
   /// straight-forward nodes and edges, this is the place to put all of the
   /// custom stuff necessary.  The GraphWriter object, instantiated with your

include/llvm/Support/GraphWriter.h

@@ -146,11 +146,11 @@ public:
 
       for (unsigned i = 0; EI != EE && i != 64; ++EI, ++i) {
         if (i) O << "|";
-        O << "<g" << i << ">" << DOTTraits::getEdgeSourceLabel(Node, EI);
+        O << "<s" << i << ">" << DOTTraits::getEdgeSourceLabel(Node, EI);
       }
 
       if (EI != EE)
-        O << "|<g64>truncated...";
+        O << "|<s64>truncated...";
       O << "}";
       if (DOTTraits::renderGraphFromBottomUp()) O << "|";
     }
@@ -163,6 +163,20 @@ public:
         O << "|" << (void*)Node;
     }
 
+    if (DOTTraits::hasEdgeDestLabels()) {
+      O << "|{";
+
+      unsigned i = 0, e = DOTTraits::numEdgeDestLabels(Node);
+      for (; i != e && i != 64; ++i) {
+        if (i) O << "|";
+        O << "<d" << i << ">" << DOTTraits::getEdgeDestLabel(Node, i);
+      }
+
+      if (i != e)
+        O << "|<d64>truncated...";
+      O << "}";
+    }
+
     O << "}\"];\n";   // Finish printing the "node" line
 
     // Output all of the edges now
@@ -223,10 +237,10 @@ public:
 
     O << "\tNode" << SrcNodeID;
     if (SrcNodePort >= 0)
-      O << ":g" << SrcNodePort;
+      O << ":s" << SrcNodePort;
     O << " -> Node" << reinterpret_cast<const void*>(DestNodeID);
     if (DestNodePort >= 0)
-      O << ":g" << DestNodePort;
+      O << ":d" << DestNodePort;
 
     if (!Attrs.empty())
       O << "[" << Attrs << "]";

lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp

@@ -32,6 +32,37 @@ using namespace llvm;
 namespace llvm {
   template<>
   struct DOTGraphTraits<SelectionDAG*> : public DefaultDOTGraphTraits {
+    static bool hasEdgeDestLabels() {
+      return true;
+    }
+
+    static unsigned numEdgeDestLabels(const void *Node) {
+      return ((const SDNode *) Node)->getNumValues();
+    }
+
+    static std::string getEdgeDestLabel(const void *Node, unsigned i) {
+      return ((const SDNode *) Node)->getValueType(i).getMVTString();
+    }
+
+    /// edgeTargetsEdgeSource - This method returns true if this outgoing edge
+    /// should actually target another edge source, not a node.  If this method is
+    /// implemented, getEdgeTarget should be implemented.
+    template<typename EdgeIter>
+    static bool edgeTargetsEdgeSource(const void *Node, EdgeIter I) {
+      return true;
+    }
+
+    /// getEdgeTarget - If edgeTargetsEdgeSource returns true, this method is
+    /// called to determine which outgoing edge of Node is the target of this
+    /// edge.
+    template<typename EdgeIter>
+    static EdgeIter getEdgeTarget(const void *Node, EdgeIter I) {
+      SDNode *TargetNode = *I;
+      SDNodeIterator NI = SDNodeIterator::begin(TargetNode);
+      std::advance(NI, I.getNode()->getOperand(I.getOperand()).ResNo);
+      return NI;
+    }
+
     static std::string getGraphName(const SelectionDAG *G) {
       return G->getMachineFunction().getFunction()->getName();
     }
@@ -88,12 +119,6 @@ std::string DOTGraphTraits<SelectionDAG*>::getNodeLabel(const SDNode *Node,
                                                         const SelectionDAG *G) {
   std::string Op = Node->getOperationName(G);
 
-  for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
-    if (Node->getValueType(i) == MVT::Other)
-      Op += ":ch";
-    else
-      Op = Op + ":" + Node->getValueType(i).getMVTString();
-    
   if (const ConstantSDNode *CSDN = dyn_cast<ConstantSDNode>(Node)) {
     Op += ": " + utostr(CSDN->getValue());
   } else if (const ConstantFPSDNode *CSDN = dyn_cast<ConstantFPSDNode>(Node)) {