Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -144,6 +144,17 @@
 
 - ...
 
+Modified Pragmas in Clang
+-------------------------
+
+- The #pragma "clang loop vectorize_width" has been extended to support an
+  optional 'fixed|scalable' argument, which can be used to indicate that the
+  compiler should use fixed-width or scalable vectorization.  Fixed-width is
+  assumed by default.  Scalable vectorization is an experimental feature for
+  targets that support it, such as Arm targets that support the Scalable Vector
+  Extension (SVE) feature. For more information please refer to the
+  Clang Language Extensions documentation.
+
 Attribute Changes in Clang
 --------------------------