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Re: m68k bootstrapping broken


Bernardo Innocenti <bernie@develer.com> writes:

> Richard Zidlicky wrote:
>> Hi,
>> bootstrapping with "languages=c" just completed. The argpointer
>> elimination problem still remains - crosscompiler does it correctly,
>> bootstrapped compiler doesnt.
>
> I've seen this too, but it doesn't always seem to be
> related with argptr elimination.
>
> Look at this change between stage2/mkdeps.o and
> stage3/mkdeps.o:
>
>  00000000 <munge>:
>     0:  4e56 0000       linkw %fp,#0
>     4:  48e7 3020       moveml %d2-%d3/%a2,%sp@-
> -   8:  242e 0008       movel %fp@(8),%d2
> -   c:  2442            moveal %d2,%a2
> +   8:  246e 0008       moveal %fp@(8),%a2
> +   c:  240a            movel %a2,%d2
>     e:  91c8            subal %a0,%a0
>    10:  1012            moveb %a2@,%d0
>    12:  6718            beqs 2c <munge+0x2c>
>
> Both versions are fine, but I wonder why a different
> instruction pattern has been generated.

I see such spurious differences from time to time on ia64 as well.  It
looks like a generic problem.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Maxfeldstraße 5, 90409 Nürnberg, Germany
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