Add a note about a missing optimization in the case of virtual
inheritance.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153722 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/NOTES.txt b/NOTES.txt
index 9f7ed4b..ca46d1c 100644
--- a/NOTES.txt
+++ b/NOTES.txt
@@ -101,3 +101,14 @@
metaprogramming.
//===---------------------------------------------------------------------===//
+
+We can still apply a modified version of the constructor/destructor
+delegation optimization in cases of virtual inheritance where:
+ - there is no function-try-block,
+ - the constructor signature is not variadic, and
+ - the parameter variables can safely be copied and repassed
+ to the base constructor because either
+ - they have not had their addresses taken by the vbase initializers or
+ - they were passed indirectly.
+
+//===---------------------------------------------------------------------===//
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index b452c1b..6303e20 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -731,6 +731,9 @@
EHScopeStack::stable_iterator CleanupDepth = EHStack.stable_begin();
+ // TODO: in restricted cases, we can emit the vbase initializers of
+ // a complete ctor and then delegate to the base ctor.
+
// Emit the constructor prologue, i.e. the base and member
// initializers.
EmitCtorPrologue(Ctor, CtorType, Args);
