https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110796
--- Comment #9 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- proc add_options_for_ieee { flags } { if { [istarget alpha*-*-*] || [istarget sh*-*-*] } { return "$flags -mieee" } if { [istarget rx-*-*] } { return "$flags -mnofpu" } return $flags } So it looks like this isn't expecting to add anything in most cases.