SEL_RPL
testb $SEL_RPL,IRETQ_CS(%rsp) ; \
#define ISPL(s) ((s) & SEL_RPL) /* what is the priority level of a selector */
#define IDXDYNSEL(s) ((((s) & ~SEL_RPL) - DYNSEL_START) >> 4)
#define ISPL(s) ((s) & SEL_RPL) /* what is the priority level of a selector */