On 10/01/2014 09:04 AM, Andy Lutomirski wrote: > > Agner Fog's tables for Sandy Bridge have 9 uops for popf and > reciprocal throughput 18. sti isn't listed for Sandy Bridge or > anything similar, but cld is 3 uops with reciprocal throughput 4. > Also, popf accesses rsp, and the sysenter code is very heavy on stack > manipulation. > It does a stack operation. Newer CPUs optimize stack accesses pretty heavily. That doesn't mean back-to-back push/pop are all that optimized, I wonder if it would help separating them. popf is unlikely to ever be all that fast. -hpa -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html