diff --git a/test/440-stmp/info.txt b/test/440-stmp/info.txt
new file mode 100644
index 0000000..c4a7bf1
--- /dev/null
+++ b/test/440-stmp/info.txt
@@ -0,0 +1,3 @@
+Regression test for optimizing, that used to consider
+a S/D register a temp, while it conflicted with the
+hard-float calling convention.