Subj : Re: Memory visibility and MS Interlocked instructions
To   : comp.programming.threads
From : Peter Dimov
Date : Fri Aug 26 2005 03:48 am

Alexander Terekhov wrote:
> Joe Seigh wrote:
> [...]
> > So what's the point other than a control dependent barrier is slower
> > then a plain load/load and is no more functional?
>
> It's no slower. The speed and effects of the dumbest implementation of
> op(msync::cchlb{_path}) is the same as op(msync::acq). It can be done
> better.

But to be done better, it requires a _very_ smart compiler, right?

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:

.