## Exit with exit status 42 on AMD64 Linux.  Compiled with
        ## `gcc -nostdlib -static` and executed with `valgrind
        ## --tool=cachegrind` we get the report “I refs: 3”.  This is
        ## probably close to the shortest Linux program execution you
        ## can do: three machine instructions.  Of course the kernel
        ## is still executing something like 150,000 instructions to
        ## create and tear down the process...
        .intel_syntax noprefix
        .equ __NR_exit, 60      # from /usr/include/x86_64-linux-gnu/asm/unistd_64.h
        .globl _start
_start: mov edi, 42             # return code goes in AMD64 first argument register
        mov eax, __NR_exit      # system call number goes in RAX
9        syscall