MFENCE vs. LOCK addl

[John Rose]

On Feb 25, 2009, at 3:39 PM, Peter B. Kessler wrote:

> I think xchg only implies lock if one of the operands is in memory,  
> but I'm looking at the Intel books, not the AMD ones.
> John Rose wrote:
>> What about XCHG?  It doesn't set flags, and (as a bonus) it implies  
>> the effect of a LOCK prefix:
>>    push rax
>>    xchg rax
Oops, sorry; I meant xchg rax, Address(rsp, 0)
>>    pop rax