Subj : Re: Memory visibility and MS Interlocked instructions
To   : comp.programming.threads
From : Alexander Terekhov
Date : Fri Aug 26 2005 01:04 pm


Peter Dimov wrote:
[...]
> But to be done better, it requires a _very_ smart compiler, right?

Nah. Just smart. ;-) 

> 
> if( load(&v, ccacq_true) == 0 )
> {
>   // #1
> }
> else
> {
>   // #2
> }
> 
>  load r1, v
>  cmp r1, 0
>  bne @2
> 
> @1:
>  isync
>  #1
>  b @3
> 
> @2:
>  #2
> 
> @3:

Yep. And compiler can hoist loads and stores on #2 and #3 pathes 
(move'em above if... suppose that control always rich #3).

regards,
alexander.

.