Gordan Bobic wrote: > Chris Tyler wrote: >> On Wed, 2010-12-22 at 08:01 -0800, Andrew Burgess wrote: >>> On 12/22/2010 06:30:13 AM, Chris Tyler wrote: >>> >>>> There is an expected performance gain with the switch to hardfp, but >>>> that's a big challenge: you can't mix softfp and hardfp, so >>>> switching to >>>> hardfp is like bootstrapping an entirely new architecture. >>> Since fedora has no problem mixing 32 and 64 bit executables it >>> seems like there's alot of infrastructure already done for this. >>> Just saying... >> >> It's not a Fedora infrastructure issue, the ABIs are incompatible. I >> wish you could mix'n'match but that doesn't look possible. > > What about kernel level FPU emulation? Is there such a thing? I could > have sworn there used to be something that could be used as such. And it > might be possible to make it quite transparent if it isn't required (so > you can always have it in the kernel). Have the kernel trap the > exception on the missing FPU instructions, save state, and then pass the > to an emulation library. When that returns, restore state and resume. > > It would mean much slower performance than softfp on FPU-less hardware, > but it would allow for a transitional period where only VFP distro needs > to be maintained, which still works (albeit slowly) on a non-VFP processor. > > Then again, I'm not volunteering to add such a feature to the Linux > kernel. :) And just as I hit send, I found this: http://netwinder.osuosl.org/users/s/scottb/public_html/notes/FP-Notes-all.html No idea how relevant it might still be - the article is about 11 years old. Gordan _______________________________________________ arm mailing list arm@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/arm
