// ASM stream — symbol operand (`"s"`): feed a function/global SYMBOL into the
// template so a DIRECT `bl %[fn]` (PC-relative, one fewer indirection than a
// register-indirect `blr`) branches straight to it, with the platform-mangled
// name emitted by the backend (so the template stays portable — no hardcoded
// `_` underscore). Not yet implemented — rejected at lowering for now. The next
// commit implements it and flips this example to run (sx → asm → sx, → 42).
cb :: (n: i64) -> i64 export "cb" { return n + 1; }

tramp :: (n: i64) -> i64 {
    return asm volatile {
        #string ASM
        stp x29, x30, [sp, #-16]!
        mov x0, %[arg]
        bl %[fn]
        mov %[res], x0
        ldp x29, x30, [sp], #16
ASM,
        [res] "=r" -> i64,
        [arg] "r" = n,
        [fn]  "s" = cb,             // symbol operand → direct `bl _cb`
        clobbers(.x0, .x30, .memory),
    };
}
main :: () -> i64 { return tramp(41); }