Add some debug routines to SelectionDAG to dump full DAGs.

print/dumpWithDepth allows one to dump a DAG up to N levels deep.
dump/printWithFullDepth prints the whole DAG, subject to a depth limit
on 100 in the default case (to prevent infinite recursion).

Have CannotYetSelect to a dumpWithFullDepth so it is clearer exactly
what the non-matching DAG looks like.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93538 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 44 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index cb1a0d660b..b8ac005952 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5893,6 +5893,49 @@ void SDNode::print(raw_ostream &OS, const SelectionDAG *G) const {
   print_details(OS, G);
 }
 
+void SDNode::printWithDepth(raw_ostream &OS, const SelectionDAG *G,
+                            unsigned depth, unsigned indent,
+                            bool limit) const {
+  if (depth == 0) {
+    if (limit)
+      OS << "*** <max depth> - Cycle? ***\n";
+    return;
+  }
+
+  int myindent = indent;
+
+  while (myindent--) {
+    OS << ' ';
+  }
+
+  print(OS, G);
+
+  if (depth > 1) {
+    for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+      OS << '\n';
+      getOperand(i).getNode()->printWithDepth(OS, G,
+                                              depth > 0 ? depth-1 : depth,
+                                              indent+2);
+    }
+  }
+} 
+
+void SDNode::printWithFullDepth(raw_ostream &OS, const SelectionDAG *G,
+                                unsigned indent) const {
+  // Don't print impossibly deep things.
+  printWithDepth(OS, G, 100, indent, true);
+} 
+
+void SDNode::dumpWithDepth(const SelectionDAG *G, unsigned depth,
+                           unsigned indent, bool limit) const {
+  printWithDepth(dbgs(), G, depth, indent, limit);
+}
+
+void SDNode::dumpWithFullDepth(const SelectionDAG *G, unsigned indent) const {
+  // Don't print impossibly deep things.
+  dumpWithDepth(G, 100, indent, true);
+} 
+
 static void DumpNodes(const SDNode *N, unsigned indent, const SelectionDAG *G) {
   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
     if (N->getOperand(i).getNode()->hasOneUse())
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 9ac8f83ad4..e53966426c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1426,7 +1426,7 @@ void SelectionDAGISel::CannotYetSelect(SDNode *N) {
   std::string msg;
   raw_string_ostream Msg(msg);
   Msg << "Cannot yet select: ";
-  N->print(Msg, CurDAG);
+  N->printWithFullDepth(Msg, CurDAG);
   llvm_report_error(Msg.str());
 }