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

2 files changed, 36 insertions, 4 deletions

diff --git a/include/llvm/Support/DOTGraphTraits.h b/include/llvm/Support/DOTGraphTraits.h
index 080c09b5f4..2367c0e260 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 afb2f545bb..20e85cce7d 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 << "]";