https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108310
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- void f(float); void g() { f(1.0); } conv.c: In function ‘g’: conv.c:5:5: warning: passing argument 1 of ‘f’ as ‘float’ rather than ‘double’ due to prototype 5 | f(1.0); | ^~~