> So, what about the patch? I think since we already have zee patch it > would be great to use it as more general optimization. I tested it on > EEMBC 2.0 on Atom and it showed 1% performance gain in geomean on 32 > bit which is really good for such simple optimization. For OOO archs > patch is not so critical but still makes code cleaner
The patch cannot be accepted as-is since it doesn't update a single bit of the documentation present in implicit-zee.c. The authors have made the effort of thoroughly documenting their code so it shouldn't be wasted. Therefore, at a minimum, the documentation must be overhauled the same way the code will be. I agree that the numbers are encouraging. Moreover, the narrow specialization of the pass was critized when it was added so a generalization will probably be welcome. So, unless other developers object, let's do it, but correctly, that is to say, let's rename the pass, eliminate all the hardcoded references to implicit zero-extensions in the code and turn it into a generic elimination of redundant extensions pass. -- Eric Botcazou
