[Coroutines] Updated with reviewer feedback

Author: tnowicki

llvm/include/llvm/Analysis/LazyCallGraph.h

@@ -1081,12 +1081,15 @@ class LazyCallGraph {
 
   /// Add new ref-recursive functions split/outlined from an existing function.
   ///
-  /// The new functions may only reference the original function or other
-  /// functions that the original function did. New functions must not call
-  /// other new functions.
+  /// The new functions may only reference other functions that the original
+  /// function did. The new functions may reference the original function. New
+  /// functions must not call other new functions or the original function.
   ///
-  /// Mark the original function as referencing all new functions.
-  /// Mark all new functions as referencing each other.
+  /// Marks the original function as referencing all new functions.
+  ///
+  /// The CG must be updated following the use of this helper, for example with
+  /// updateCGAndAnalysisManagerForCGSCCPass(), to ensure the RefSCCs and SCCs
+  /// are correctly identified.
   void addSplitRefRecursiveFunctions(Function &OriginalFunction,
                                      ArrayRef<Function *> NewFunctions);
 

llvm/lib/Analysis/LazyCallGraph.cpp

@@ -1733,23 +1733,6 @@ void LazyCallGraph::addSplitRefRecursiveFunctions(
     }
   }
 
-  for (Function *NewFunction : NewFunctions) {
-    Node &NewN = get(*NewFunction);
-    for (Function *OtherNewFunction : NewFunctions) {
-      if (NewFunction == OtherNewFunction)
-        continue;
-
-      Node &OtherNewN = get(*OtherNewFunction);
-
-      // Don't add an edge if one already exists.
-      if (NewN->lookup(OtherNewN))
-        continue;
-
-      // Make the new function reference each other new function
-      NewN->insertEdgeInternal(OtherNewN, Edge::Kind::Ref);
-    }
-  }
-
   RefSCC *NewRC;
   if (ExistsRefToOriginalRefSCC) {
     // If there is any edge from any new function to any function in the
@@ -1793,7 +1776,7 @@ void LazyCallGraph::addSplitRefRecursiveFunctions(
       if (F1 == F2)
         continue;
       Node &N2 = get(*F2);
-      assert(N1->lookup(N2) &&
+      assert(!N1->lookup(N2) ||
              (!N1->lookup(N2)->isCall() &&
               "Edges between new functions must be ref edges"));
     }