# HG changeset patch
# User Nick Wellnhofer <wellnhofer@aevum.de>
# Date 1645388810 -3600
#      Sun Feb 20 21:26:50 2022 +0100
# Node ID fc618c357b3c1c5420d329b6ce95f2421577b92d
# Parent  b114cbc268184dcb5f0ea9024479697bb266c798
Add note about optimization flags

diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -44,6 +44,11 @@
     ./configure [possible options]
     make
 
+Note that by default, no optimization options are used. You have to
+enable them manually, for example with:
+
+    CFLAGS='-O2 -fno-semantic-interposition' ./configure
+
 Now you can run the test suite with:
 
     make check