Mention that -O4 does result in more optimization when used with
-fplugin-arg-dragonegg-enable-gcc-optzns, though it usually isn't
a win.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145486 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index 9747158..a2b0177 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -174,7 +174,9 @@
<li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs
GCC's optimizers as well as LLVM's, now works much better. This is the
option to use if you want ultimate performance! It is still experimental
- though: it may cause the plugin to crash.</li>
+ though: it may cause the plugin to crash. Setting the optimization level
+ to <tt>-O4</tt> when using this option will optimize even harder, though
+ this usually doesn't result in any improvement over <tt>-O3<tt>.</li>
<li>The type and constant conversion logic has been almost entirely rewritten,
fixing a multitude of obscure bugs.</li>