Compiler/Interpreter Validation Guidelines for C?

pjdepasq asks: "For my PhD work, I've developing a programming environment for novice users. It basically interprets the C programming language, plus or minus a few things as we teach the novice programming course here at Virginia Tech. In doing so, I'd like to have one of the students working with me use a compiler validation guideline to validate we're covering the key bases. For example, initially, I'd like them to ensure that the operator precendence is working correctly. My advisor tells me that NIST used to have a software product for doing this, but I don't see it there any longer for C. I'd really just be happy with some type of guide that the student can work from. Does anyone know of some type of free/cheap guideline we can utilize? It would likely need to include other types of validation, since we'll expand this effort later in the semester."