On 19/08/16 17:15, C Bergström wrote: > On Fri, Aug 19, 2016 at 11:01 PM, Luca Barbato <lu_z...@gentoo.org> wrote: >> BTW is pathscale ready to be used as system compiler as well? > > I wish, but no. We have known issues when building grub2, glibc and > the Linux kernel at the very least. Someone* did report a long time > ago that with their unofficial port, were able to build/boot the > NetBSD kernel. > (*A community dev we trusted with our sources and was helping us with > portability across platforms) > > The stuff with grub2 may potentially be fixed in the "near" future... > the others are more tricky. In general if clang can do it, we have a > strong chance as well.
I see, it is getting quite close =) > As a philosophy - "we" aren't really trying to be the best generic > compiler in the world. We aim more on optimizing as much for known > targets. So if by system you mean, a compiler that would produce an > "OS" which only runs on a single class of hardware, then yeah it could > work at some point in the future. Specifically, on x86 we default on > host CPU optimizations. So on newer Intel hardware it's easy to get a > binary that won't run on AMD or older 64bit Intel. > > More recently on ARMv8 - we turn on processor specific tuning. So > while it may "run", the difference between APM's mustang and Cavium > ThunderX is pretty big and running binaries intended for A and ran on > B would certainly take a hit.. (this is just the tip of the iceberg) This is not a problem for Gentoo, actually sounds a good match for one of our many use-cases =) > For HPC codes or anything where you get loops or computationally > complex - the gloves are off and I could see big differences... (again > being general and maybe a bit dramatic for fun) I started to do some decoding benchmark across compiler version some time ago, I should try to put in the mix your compiler as well and eventually blog about it =) lu
