volatile semantics

[Olivier Galibert]

On Sun, Jul 17, 2005 at 11:56:46AM -0700, Geoffrey Keating wrote:
> "D. Hugh Redelmeier" <hugh@mimosa.com> writes:
> > An object that has volatile-qualified type may be modified in ways
> > unknown to the implementation or have other unknown side
> > effects. Therefore any expression referring to such an object shall be
> > evaluated strictly according to the rules of the abstract machine
> 
> The word you missed is 'Therefore'.  If an implementation can
> determine that an object is not modified unknown to the
> implementation, the implementation need not evaluate it strictly
> according to the rules of the abstract machine.

I don't read it that way.  I read it as "whatever the implementation
may think, it can _not_ determine whether the object may be
modified/has side effects unknown to it".

  OG.