https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66554
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> --- Indeed: > ./cc1plus -quiet t.ii -O3 -I include t.ii: In function ‘void fn1()’: t.ii:3:6: error: invalid types in conversion to integer void fn1() { ^ vector(4) signed int vector(4) unsigned int vect__13.24_98 = (vector(4) signed int) vect_c.21_94; Jakub, isn't this just PR66233?