=> 0x7fa77e53af96:	mov    (%rdi),%rbx
   0x7fa77e53af99:	test   %rbx,%rbx
   0x7fa77e53af9c:	je     0x7fa77e53afb8
   0x7fa77e53af9e:	mov    %rbx,%rax
   0x7fa77e53afa1:	mov    0x8(%rsp),%rbp
   0x7fa77e53afa6:	mov    (%rsp),%rbx
   0x7fa77e53afaa:	mov    0x10(%rsp),%r12
   0x7fa77e53afaf:	add    $0x18,%rsp
   0x7fa77e53afb3:	retq   
   0x7fa77e53afb4:	nopl   0x0(%rax)
   0x7fa77e53afb8:	callq  0x7fa77e53aee0
   0x7fa77e53afbd:	mov    %rax,%r12
   0x7fa77e53afc0:	mov    %rbx,%rax
   0x7fa77e53afc3:	lock cmpxchg %r12,0x0(%rbp)
   0x7fa77e53afc9:	jne    0x7fa77e53afd1
   0x7fa77e53afcb:	mov    0x0(%rbp),%rbx