Re: gcc -m68060 option in kernel Makefiles
Frank Wille <[email protected]> Sat, 17 Jan 2009 12:02:44 +0100
| Newsgroups | gmane.os.netbsd.ports.amiga,gmane.os.netbsd.ports.atari |
|---|---|
| Organization | Privates Internet Ostwestfalen/Lippe e.V. |
| Message-ID | <[email protected]> |
Ignatios Souvatzis wrote:
> Hm, what does Amiga have? Back then, I knew what I did - which I don't
> do any longer by heart, and I'm 400 km away from my 68060 book.
>
> I seem to recall that -m68060 is fine as long as you don't do floating
> point stuff (same as 68040, btw!) or MMU, and we don't do FP stuff
> in kernel C code, and gcc doesn't do MMU stuff, so it wouldn't make
> a difference.
>
> The FPU stuff is explicit limited precision arithmetic - contrary to
> setting the precision and then do the generic operations, which is
> what you have to do with the 68881 or 68882.
>
> Do I recall correctly?
IIRC...
- The 64/32 integer division (DIV?.L Dn,Dr:Dq) has to be emulated.
- The 32*32->64 bit integer multiplication (MUL?.L) has to be emulated.
--
_ Frank Wille ([email protected])
_ // http://sun.hasenbraten.de/~frank/
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