https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33661
--- Comment #15 from Alexey Dobriyan <adobriyan at gmail dot com> --- I can only reconfirm this bug still exists with 8.2.0 after rediscovering it independently. Linux system calls taking 4+ arguments can't be templatized as they require register T3 _a3 asm("r10") = a3; But using "r10" (a3) in assembly input constraints doesn't work either.