1 files changed, 3 insertions, 0 deletions
diff --git a/README b/README
index 4b13076f..41ebffa5 100644
--- a/README
+++ b/README
@@ -73,10 +73,13 @@ On Apple macOS, install Xcode and brew.sh, then in the Terminal enter:
 
 2) Compiling the source
 
+    % git submodule update --init
     % ./autogen.sh
     % ./configure
     % make
 
+On x86, it's a good idea to use a -march= option that allows the use of AVX2.
+
 3) Install the codec libraries (optional)
 
     % sudo make install