On Tue, May 5, 2009 at 7:00 AM, Xinliang David Li <davi...@google.com> wrote: > Hi, I am going to create a gcc branch for the functionality of > lightweight IPO. The description of the project and current status can > be found in http://gcc.gnu.org/wiki/LightweightIpo. Some highlights: > > 1) If you already use FDO in your build, you also get IPO almost for free; > 2) It is an IPO solution practical to very large real world C++ applications; > 3) Performance potential is very large (though I've seen case > increased compiler freedom can lead to performance degradation due to > over-optimization (inliner, unroller etc) -- but this is a different > matter). > > If the idea is generally accepted, I will prepare a series of patches > and submit them to gcc trunk.
I was hoping that with LTO we can get rid of -combine, as its type/decl merging is fragile in many cases. Does this somehow conflict with LIPO? From what I understand is that you are merging TUs in the frontend (like -combine) - did you consider merging TUs with the LTO infrastructure, but in memory? On the whole LIPO sounds indeed very interesting. Thanks, Richard.
