Subj : Re: Memory Barriers, Compiler Optimizations, etc.
To   : comp.programming.threads
From : David Schwartz
Date : Tue Feb 08 2005 12:27 pm


"Ziv Caspi" <zivca@netvision.net.il> wrote in message 
news:cu2548$189$3@news2.netvision.net.il...


> In any case, C/C++ provides no mechanism to prevent the processor itself 
> from reordering, so even if you belong to the first group, you get no 
> standard guarantees.

    I can't believe it! How can you possibly argue that the C/C++ standard 
imposes requirements on the *compiler* that the *processor* is free to 
violate and still comply with the standard? That's utterly absurd.  If the 
compiler can't generate code that prevents the processor from violating the 
C/C++ standard, the compiler does not conform. Period.

> Note that the guarantees we currently provide hold only for the platforms 
> Windows and CL run on -- x86, x64, and Itanium. We currently don't provide 
> a guaranteed "future-proof" model for future platforms, although some of 
> us would really like us to do so...

    In other words, it is *not* the official position that the C/C++ 
standard requires such things.

    DS

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