------- Comment #12 from law at redhat dot com 2009-02-26 16:53 ------- Subject: Re: [4.3/4.4 Regression] GCSE-optimization causes enormous binary size increase (~20 times !)
steven at gcc dot gnu dot org wrote: > ------- Comment #10 from steven at gcc dot gnu dot org 2009-02-21 16:09 > ------- > OK, I checked what we're PREing here. This is indeed partial-partial PRE. > > I suppose something like the following is a good idea. I'll admit it's > brute-force, but I'm not sure how else to stop GCSE-PRE from doing this (it's > baked into the LCM equations). > > Jeff, what do you think about this PR? > It's overkill, but overkill I can live with -- it'd be marginally better if we waited until we were sure that insertion on those edges was needed rather than just blindly forgetting everything we know about these blocks with a high in-degree. It'd also be marginally better if we had a better metric than just in-degree -- specifically if we had some idea of how many redundancies get eliminated. This would be a nice future enhancement. I'll OK this after turning the in-degree check to use a PARAM. Jeff -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39077
