Re: Merging few files from i386/amd64 into x86

[Andrew Doran <ad%netbsd.org@localhost>]

On Sun, Mar 29, 2009 at 07:27:42PM +0100, Mindaugas Rasiukevicius wrote:

> David Young <dyoung%pobox.com@localhost> wrote:
> > Can you avoid using new #ifdefs, or else confine them to the top of the
> > file?  They make even straightforward code hard to read. :-/
> 
> My goal is a little bit different than sprinkling #ifdefs in random places. ;)
> 
> > The vm_machdep.c are so alike that I wonder if you can pull out most of
> > the code that is the same and stick it into sys/arch/x86/ ?
> > 
> > I had a look at vm_machdep.c with a mind to reduce purely cosmetic
> > differences.  I made the attached compilable but untested patch.  ISTR
> > the differences can be reduced further by a few minor changes: for
> > example, rename npxsave_lwp to fpusave_lwp.
> 
> I have committed various cosmetic reductions yesterday, including some
> changes to vm_machdep.c code which are similar to yours (noticed your
> email just today, since I was not in CC). Ideally, those #if NNPX > 0
> should be removed by making npxsave_lwp() et al empty stubs.

Contrary to what the configuration files suggest fpu support is not
optional. The fpu code can easily be shared between amd64/i386 because i386
no longer needs the 80387 support. A small hurdle is register naming.
Another is XEN support, which will differ between the two architectures.

I have heard it said that npx should be included in the device tree because
it uses various system resources. Fair enough, but from what I remember 
there are other ports and they differ between cpu families.