Subj : Re: Memory Barriers, Compiler Optimizations, etc.
To   : comp.programming.threads
From : Joseph Seigh
Date : Mon Feb 07 2005 08:17 am

On Mon, 07 Feb 2005 13:46:03 +0100, Alexander Terekhov <terekhov@web.de> wrote:

>
> Joseph Seigh wrote:
>>
>> On Mon, 07 Feb 2005 11:17:07 +0100, Alexander Terekhov <terekhov@web.de> wrote:
>>
>> >
>> > Yes. Note that I said "volatile abuse". Simply put, when you write
>> > something like
>> >
>> > volatile int i = 1;
>> >
>> > int main() {
>> >   return --i;
>> > }
>> >
>> > you better be prepared that smart compiler can tranform it to
>> >
>> > int main() {
>> > }
>> >
>>
>> The variable i doesn't have an external attribute.  It can't be
>> seen anyway.
>
> And since the C/C++ standards don't concern themselves with threads,
> use of "internal" volatiles by multiple threads doesn't constitute
> "external attribute" in your terminology. IOW, C/C++ compiler can
> simply ignore volatile abuse and treat all such variables as
> nonvolatile.
>

Yes, but you didn't have any threads in your example.  You need to come
up with more realistic examples.

-- 
Joe Seigh

.