__register_t
__register_t mc_onstack; /* XXX - sigcontext compat. */
__register_t mc_rdi;
__register_t mc_rsi;
__register_t mc_rdx;
__register_t mc_rcx;
__register_t mc_r8;
__register_t mc_r9;
__register_t mc_rax;
__register_t mc_rbx;
__register_t mc_rbp;
__register_t mc_r10;
__register_t mc_r11;
__register_t mc_r12;
__register_t mc_r13;
__register_t mc_r14;
__register_t mc_r15;
__register_t mc_xflags;
__register_t mc_trapno;
__register_t mc_addr;
__register_t mc_flags;
__register_t mc_err;
__register_t mc_rip;
__register_t mc_cs;
__register_t mc_rflags;
__register_t mc_rsp; /* machine state */
__register_t mc_ss;
typedef __register_t register_t; /* register-sized type */