https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77415
--- Comment #1 from Gerhard Steinmetz <gerhard.steinmetz.fort...@t-online.de> --- With official releases (configured with --enable-checking=release), down to at least 4.8 : $ gfortran-6 z1.f90 z1.f90:1:0: integer function f() internal compiler error: in make_decl_rtl, at varasm.c:1292