Index: docs/ReleaseNotes.rst
===================================================================
--- docs/ReleaseNotes.rst
+++ docs/ReleaseNotes.rst
@@ -45,6 +45,10 @@
 * Symbols starting with ``?`` are no longer mangled by LLVM when using the
   Windows ``x`` or ``w`` IR mangling schemes.
 
+* A new tool named `llvm-mca` has been added. `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