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Re: Results for egcs-2.92.23 19981122 (gcc2 ss-980609 experimental) testsuite on i386-unknown-openbsd2.4
- To: Andreas Schwab <schwab at issan dot informatik dot uni-dortmund dot de>
- Subject: Re: Results for egcs-2.92.23 19981122 (gcc2 ss-980609 experimental) testsuite on i386-unknown-openbsd2.4
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Sat, 28 Nov 1998 10:06:00 -0700
- cc: Marc dot Espie at liafa1 dot liafa dot jussieu dot fr, egcs at cygnus dot com, egcs-bugs at cygnus dot com
- Reply-To: law at cygnus dot com
In message <vyz90gxxy76.fsf@issan.cs.uni-dortmund.de>you write:
> Marc Espie <espie@quatramaran.ens.fr> writes:
>
> |> I should add that I STILL can't give you any results for
> |> m68k-unknown-openbsd2.4 as I am still running into the same wall:
> |>
> |> compilation of libgcc2 by xgcc for _bb ends up with an ICE
> |> in expmed.c: 2594: Internal compiler error in function choose_multiplier
>
> This is a bug in reload, it kills the REG_UNUSED notes, which cannot be
> recomputed accurately. As a result the second stage compiler is
> miscompiled (more exactly the function div_and_round_double which is
> called by choose_multiplier). Here is a patch:
>
>
> 1998-11-01 Andreas Schwab <schwab@issan.cs.uni-dortmund.de>
>
> * reload1.c (reload): Don't remove REG_UNUSED notes here, it is
> impossible in general to recompute them accurately afterwards.
You still haven't resolved the issue I raised earlier this month about this
patch. Let's get the issue resolved so that we can install your patch.
[ ... ]
Ugh. Conceptually I think the patch is OK. Do we need to worry about
flow2 adding another REG_UNUSED note to an insn with an existing REG_UNUSED
note? That could be bad (then again, maybe not). I think we need to resolve
this issue (if we need to do anything), then install the resulting patch.
I can't think of any cases where REG_UNUSED notes were inaccurate after
reload, so I doubt keeping them is going to hurt anything.
jeff