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

[John Regehr <regehr@cs.utah.edu>]

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:

  http://www.hpl.hp.com/personal/Hans_Boehm/misc_slides/c++mm.pdf

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.

John