Index: docs/ReleaseNotes.rst
===================================================================
--- docs/ReleaseNotes.rst
+++ docs/ReleaseNotes.rst
@@ -45,6 +45,11 @@
 * Symbols starting with ``?`` are no longer mangled by LLVM when using the
   Windows ``x`` or ``w`` IR mangling schemes.
 
+* A new tool named :doc:`llvm-mca <CommandGuide/llvm-mca>` has been added.
+  :program:`llvm-mca` is a  static performance analysis tool that uses
+  information available in LLVM to statically predict the performance of
+  machine code for a specific CPU.
+
 * Note..
 
 .. NOTE