add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33578 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/SmallPtrSet.cpp b/lib/Support/SmallPtrSet.cpp
index 0e6d334..48552a5 100644
--- a/lib/Support/SmallPtrSet.cpp
+++ b/lib/Support/SmallPtrSet.cpp
@@ -7,7 +7,8 @@
//
//===----------------------------------------------------------------------===//
//
-// This file implements the SmallPtrSet class.
+// This file implements the SmallPtrSet class. See SmallPtrSet.h for an
+// overview of the algorithm.
//
//===----------------------------------------------------------------------===//