On Thu, Feb 24, 2022 at 09:50:28AM +0100, Richard Biener wrote: > On Thu, 24 Feb 2022, Jiufu Guo wrote: > > And another thing as Segher pointed out, CSE is doing too > > much work. It may be ok to separate the constant handling > > logic from CSE. > > Not sure - CSE just is value numbering, I don't see that it does > more than that. Yes, it might have developed "heuristics" over > the years what to CSE and to what and where to substitute and > where not. But in the end it does just value numbering.
It also does various micro-optimisations, like all the CC things it does. It is not very good at doing the CSE job, but it cannot easily be replaced by a better implementation because it does many other small optimisations (that are not done elsewhere). Segher
