Have TableGen emit setSubgraphColor calls under control of a -gen-debug

flag.  Then in a debugger developers can set breakpoints at these calls
to see waht is about to be selected and what the resulting subgraph
looks like.  This really helps when debugging instruction selection.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58278 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 2 deletions

diff --git a/include/llvm/CodeGen/DAGISelHeader.h b/include/llvm/CodeGen/DAGISelHeader.h
index 3542ebc..e50ee7c 100644
--- a/include/llvm/CodeGen/DAGISelHeader.h
+++ b/include/llvm/CodeGen/DAGISelHeader.h
@@ -153,7 +153,7 @@ void ReplaceUses(SDNode *F, SDNode *T) DISABLE_INLINE {
 
 /// SelectRoot - Top level entry to DAG instruction selector.
 /// Selects instructions starting at the root of the current DAG.
-void SelectRoot() {
+void SelectRoot(SelectionDAG &DAG) {
   SelectRootInit();
   unsigned NumBytes = (DAGSize + 7) / 8;
   ISelQueued   = new unsigned char[NumBytes];
@@ -176,14 +176,18 @@ void SelectRoot() {
     // Skip already selected nodes.
     if (isSelected(Node->getNodeId()))
       continue;
+    DAG.setSubgraphColor(Node, "red");
     SDNode *ResNode = Select(SDValue(Node, 0));
     // If node should not be replaced, 
     // continue with the next one.
     if (ResNode == Node)
       continue;
     // Replace node.
-    if (ResNode)
+    if (ResNode) {
+      DAG.setSubgraphColor(ResNode, "yellow");
+      DAG.setSubgraphColor(ResNode, "black");
       ReplaceUses(Node, ResNode);
+    }
     // If after the replacement this node is not used any more,
     // remove this dead node.
     if (Node->use_empty()) { // Don't delete EntryToken, etc.
@@ -191,6 +195,7 @@ void SelectRoot() {
       CurDAG->RemoveDeadNode(Node, &ISQU);
       UpdateQueue(ISQU);
     }
+    //DAG.setSubgraphColor(Node, "black");
   }
 
   delete[] ISelQueued;