cvise and llvm-reduce are really good complements to c-reduce. Allows for mechanical reduction without any understanding of how compilers / backends are designed. I've found that it's much quicker to get a fix if I do the reduce before opening the bug.
As a compiler developer, if you give me a bug and the source is not reduced, I'm decently likely to tell you to reduce it first before I attempt to take a look at it.
Still, I try to be polite and reduce the code some before making the bug report. I don't want to come across as lazy and load you (in particular) with work I could have done.
Having said that, reduction can be tricky, and I need to do more work on that with the Common Lisp random tester, so as to allow more language constructs to be in the random code.
