> What about conditional zero_extension, sign_extension, > float_extension, ...etc? > > We have discussed this, we can have some many conditional situations > that can be supported by either match.pd or rtl backend combine > pass. > > IMHO, it will be too many optabs/internal fns if we support all of > them in match.pd? Feel free to correct me I am wrong. I think the general trend is (and should be) to push things forward in the pipeline and not just have combine fix it. However, for now this would complicate things and therefore I agree with the approach the patch takes. I'd rather have the patterns in now rather than change the middle end for unclear benefit.
IMHO long-term we want things to be optimized early but short-term combine is good enough. We can then move optimizations forward on a case-by-case basis. Regards Robin
