From 358033102ffaef4d1afb1c0b7e96440906f0b48f Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Mon, 21 Jul 2008 21:06:55 +0000
Subject: [PATCH] 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         | 18 +++++++++
 include/llvm/Support/GraphWriter.h            | 22 +++++++++--
 .../SelectionDAG/SelectionDAGPrinter.cpp      | 37 ++++++++++++++++---
 3 files changed, 67 insertions(+), 10 deletions(-)

diff --git a/include/llvm/Support/DOTGraphTraits.h b/include/llvm/Support/DOTGraphTraits.h
index 080c09b5f48..2367c0e260c 100644
--- a/include/llvm/Support/DOTGraphTraits.h
+++ b/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
diff --git a/include/llvm/Support/GraphWriter.h b/include/llvm/Support/GraphWriter.h
index afb2f545bbd..20e85cce7de 100644
--- a/include/llvm/Support/GraphWriter.h
+++ b/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 << "]";
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
index ea93d11f6dd..184c50e9037 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
+++ b/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)) {