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Re: [csmith-dev] mission drift proposal #2 -- C++0x memory model

I don't know anything about C++, so I don't know how similar the constructs are, but it would be great if what you generated could be used for C as well.  C1X has atomics with different kinds of memory ordering constraints, and of course threads with locks and mutexes.


On Thu, Jun 9, 2011 at 3:34 PM, John Regehr <regehr@cs.utah.edu> wrote:
It looks like some compilers (for example GCC) are not too far from being ready to try to comply with the C++0x memory model.  This will be a big job and they do not yet fully understand how this model will interact with their optimizer.  It's fair to say that most other C++ compilers will be running into similar issues in coming years.  We can help by adding C++0x memory model constructs to the set of things Csmith can emit.

Note that I'm not suggesting that we emit "interesting" C++, which is a very big job.  Rather, we can emit C++ that looks very much like C but that contains locks, atomics, volatiles, etc.  I can't imagine there's anything difficult about this, given the infrastructure we already have.

Hans Boehm has an excellent slide deck on what can go wrong when compiling this sort of code:


The problem of determining the correctness of a compiler's translation of a piece of code containing C++0x concurrency primitives is not trivial, but basically it's not our problem.  There exist (or will exist) some smart checking tools for this sort of thing.