1 files changed, 4 insertions, 1 deletions
diff --git a/utils/TableGen/CodeGenIntrinsics.h b/utils/TableGen/CodeGenIntrinsics.h
index f986ed1995..4bae8f15a5 100644
--- a/utils/TableGen/CodeGenIntrinsics.h
+++ b/utils/TableGen/CodeGenIntrinsics.h
@@ -34,7 +34,10 @@ namespace llvm {
     /// of the arguments.  These are things like Type::UIntTyID.
     std::vector<std::string> ArgTypes;
     
-    /// ArgVTs - The MVT::ValueType for each argument type.
+    /// ArgVTs - The MVT::ValueType for each argument type.  Note that this list
+    /// is only populated when in the context of a target .td file.  When
+    /// building Intrinsics.td, this isn't available, because we don't know the
+    /// target pointer size.
     std::vector<MVT::ValueType> ArgVTs;
     
     /// ArgTypeDefs - The records for each argument type.