Who Ordered Memory Fences on an x86?

[Walter Bright]

Nick Sabalausky wrote:
> Also, one thing I'ma little 
> nclear on, is this whole mess only applicable when multiple cores are in 
> use, or do the same problems crop up on unicore chips?

It's a problem only on multicore chips.


> Maybe I'm being naive, but would it have made more sense for CPUs to assume 
> memory accesses *cannot* be reordered unless told otherwise, instead of the 
> other way around? 

It's the way it is for performance reasons.