// ASM stream — x86_64 Linux `write(2)` via a raw `syscall`. The canonical inline-
// asm use case: SYS_write (rax=1) with fd/buf/count pinned to rdi/rsi/rdx, the
// `syscall` instruction clobbering rcx + r11 (+ memory), and the byte count
// returned in rax. Demonstrates register-pinned inputs, a pinned value output,
// a pointer input (`*u8` → rsi), and `clobbers(.…)` lowering all at once.
//
// x86-pinned via `.build`: ir-only on a non-x86 host — the `.ir` snapshot locks
// the exact constraint string (`={rax},{rax},{rdi},{rsi},{rdx},~{rcx},~{r11},
// ~{memory}`), which is the §II.11 silent-miscompile risk zone — and runs
// natively on x86_64-linux (printing "ok\n"). See 1640 for an x86 multi-output
// example, 1645/1647/1649/1650 for aarch64 examples that execute on this host.
sys_write :: (fd: i64, buf: *u8, count: i64) -> i64 {
    return asm volatile {
        "syscall",
        [ret] "={rax}" -> i64,      // return: bytes written, in rax
        "{rax}" = 1,                // SYS_write (x86_64 Linux)
        "{rdi}" = fd,               // fd
        "{rsi}" = buf,              // buf
        "{rdx}" = count,            // count
        clobbers(.rcx, .r11, .memory),
    };
}

main :: () {
    msg : [3]u8 = .[111, 107, 10];      // "ok\n"
    n := sys_write(1, @msg[0], 3);
}