*: introduce and use FAST_FUNC: regparm on i386, otherwise no-on
text data bss dec hex filename
808035 611 6868 815514 c719a busybox_old
804472 611 6868 811951 c63af busybox_unstripped
diff --git a/libbb/die_if_bad_username.c b/libbb/die_if_bad_username.c
index 337ac60..602aadc 100644
--- a/libbb/die_if_bad_username.c
+++ b/libbb/die_if_bad_username.c
@@ -16,7 +16,7 @@
* at the end of the username.
*/
-void die_if_bad_username(const char *name)
+void FAST_FUNC die_if_bad_username(const char *name)
{
goto skip; /* 1st char being dash isn't valid */
do {