Subject: Re: -msoft-float question
To: David Bushong <dbushong@cory.EECS.Berkeley.EDU>
From: Allen Briggs <briggs@puma.macbsd.com>
List: port-mac68k
Date: 03/12/1997 10:13:55
> OK, I'm compiling a kernel, and I leave out FPE and FPSP, since I have an
> '030 with fpu (IIcx).
> a) that's correct, right?

Yes.  As a couple of other folks have pointed out.

> b) why do I still get -msoft-float in my compile lines
>    i) am i supposed too and am misunderstanding the meaning of msoft-float?
>    ii) if not, how do I get rid of it?

This is in the kernel compilation to make sure that there are no floating
point instructions in the kernel.  Some systems (not 68k) have an FPU
state/context that has to be maintained.  Using FP in the kernel on
these systems would require fairly expensive saving/restoring of this
state and, in general, handling of FPU traps in the kernel.  There is
also the issue of FPU-less systems.

If you _really_ want to get rid of it, it should make no difference, but
you can remove it from sys/arch/mac68k/conf/Makefile.mac68k.  Personally,
I wouldn't worry about it.

-allen

-- 
              Allen Briggs - end killing - briggs@macbsd.com