diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 6d42d812a00..b27d99e18b5 100644
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -1965,6 +1965,7 @@ bb3:            ; preds = %entry
 //===---------------------------------------------------------------------===//
 
 clang -O3 fails to devirtualize this virtual inheritance case: (GCC PR45875)
+Looks related to PR3100
 
 struct c1 {};
 struct c10 : c1{