On Mon, 2012-09-24 at 09:55 +0200, Gabriel Paubert wrote: > On Sun, Sep 23, 2012 at 03:46:06AM +0200, Segher Boessenkool wrote: > > Why does the kernel emulate this, btw? I can see emulation is useful > > for running older binaries, for instructions that have been removed > > from the architecture; but for newly added instructions, or optional > > instructions, it hurts more than it helps? > > Indeed. I also don't understand why mfpvr is emulated. That's the kind > of information that should be passed to the executables through auxiliary > vectors. After all, you can (or could at least) compile a kernel without > Altivec support and run it on a processor with Altivec. > > Therefore, whether Altivec is supported or not, is a matter of > processor and kernel options. Provide this information through > the auxiliary vector and the problem is solved.
Which we do. mfpvr is available as a fallback (essentially because if we don't do it somebody's going to parse /proc/cpuinfo which is arguably worse :-) We should definitely advertise the availability of isel. Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
