Dear gcc list, we are trying to clarify what behaviour of C implementations is actually relied upon in modern practice, and what behaviour is guaranteed by current mainstream implementations (these are quite different from the ISO standards, and may differ in different contexts).
Focussing on the sequential behaviour of memory operations, we've collected a short survey of 15 questions about C: http://goo.gl/iFhYIr Your answers to these would be very helpful, especially if you can speak authoritatively about what gcc does (it's difficult for us to directly investigate the emergent properties of the combination of optimisations in a production compiler). This continues a research project at the University of Cambridge; in earlier work (with Batty, Owens, and Sarkar) we addressed the C/C++11 concurrency model, which resulted in fixes to the ISO standards and supports work on compiler testing (by Zappa Nardelli, Morisset, and Pawan). many thanks, Kayvan Memarian and Peter Sewell
