On Sonntag, 27. Mai 2018 00:05:32 CEST Segher Boessenkool wrote: > On Sat, May 26, 2018 at 11:32:29AM +0200, Allan Sandfeld Jensen wrote: > > I brought this subject up earlier, and was told to suggest it again for > > gcc 9, so I have attached the preliminary changes. > > > > My studies have show that with generic x86-64 optimization it reduces > > binary size with around 0.5%, and when optimizing for x64 targets with > > SSE4 or better, it reduces binary size by 2-3% on average. The > > performance changes are negligible however*, and I haven't been able to > > detect changes in compile time big enough to penetrate general noise on > > my platform, but perhaps someone has a better setup for that? > > > > * I believe that is because it currently works best on non-optimized code, > > it is better at big basic blocks doing all kinds of things than tightly > > written inner loops. > > > > Anythhing else I should test or report? > > What does it do on other architectures? > > I believe NEON would do the same as SSE4, but I can do a check. For architectures without SIMD it essentially does nothing.
'Allan
