Regehr: GCC 4.8 Breaks Broken SPEC 2006 Benchmarks

The code that is always true might not have been even written by the user, but come from a system header file, a macro expansion (but not a constant expression), or generated code (very common in C++), from transformations of the code that don't match any original code, etc.

Regardless, there are very few GCC developers, so if you think you could do something better, you should give it a try. Sometimes you realize how difficult your obvious thing turns out to be, and other times you realize that it was indeed obvious but nobody had time to do it before. I can tell you from personal experience that there is a lot of the latter in GCC.