[parisc-linux] [RFC] using 64bit wide registers with 32bit kernel

[Thibaut VARENE]

On 15 May 2006 05:10:15 -0400, Jes Sorensen <jes at sgi.com> wrote:
> >>>>> "James" == James Bottomley <James.Bottomley at SteelEye.com> writes:
>
> James> On Sat, 2006-05-13 at 17:41 +0200, Thibaut VARENE wrote:
> >> 1) we claim what I'm trying to do should not be done on
> >> parisc-linux => using ldd/std, MAX2 and other insns that rely on
> >> 64bit regs should be prohibited by binutils for non-wide code
> >> (currently gcc/binutils happily build my code with -mpa-risc-2-0,
> >> which generates level 2.0 non wide code)
>
> James> I really don't think doubling the size of our register file on
> James> all tasks and doubling the size of the saved registers on stack
> James> for interruptions is really a sensible thing to do just so some
> James> multi-media extension can be made to work.
>
> What about setting an ELF flag or somesuch, set a task flag based on
> this and then only do the extended register file backup for these
> apps?

If that's possible *and* acceptable, it might be very helpful indeed.

T-Bone

-- 
Thibaut VARENE
http://www.parisc-linux.org/~varenet/