On 02/07/2012 06:01 PM, Xin Tong wrote: > Is there a performance penalty for accessing global with rip on > architecture as new as nehalem, in comparsion to access variables > using rsp? No. >>>>> >>>> 4006f9: f0 80 0d bf 0b 20 00 lock orb $0x0,0x200bbf(%rip) >>>>> >>>> # 6012c0 <t2lockor> >>>>> >>>> 400700: 00 >>>>> >>>> 4006f9: f0 80 0d bf 0b 20 00 lock orb $0x0,0x0(%rsp) >>>>> >>>> # 6012c0 <t2lockor> >>>>> >>>> 400700: 00 > The later seems to perform better. Well, yes, it would: it's local. That means it is already in cache by the time you execute that load. Andrew.
