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Re: [PATCH] S/390: Wide int support.
- From: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- To: rdsandiford at googlemail dot com (Richard Sandiford)
- Cc: vogt at linux dot vnet dot ibm dot com, gcc-patches at gcc dot gnu dot org, Ulrich dot Weigand at de dot ibm dot com (Ulrich Weigand), krebbel at linux dot vnet dot ibm dot com (Andreas Krebbel)
- Date: Wed, 16 Dec 2015 01:24:06 +0100 (CET)
- Subject: Re: [PATCH] S/390: Wide int support.
- Authentication-results: sourceware.org; auth=none
Richard Sandiford wrote:
> "Ulrich Weigand" <uweigand@de.ibm.com> writes:
> > The problem is not DImode LABEL_REFs, but rather VOIDmode LABEL_REFs when
> > matched against a match_operand:DI.
>
> It'd be good to fix this in a more direct way though, rather than
> hack around it. It's possible that the trick will stop working
> if genrecog.c gets smarter.
>
> When do label_refs have VOIDmode? Is this an m31-ism?
No, this seems to be a cross-platform issue. For one, RTX in .md files
pretty much consistently uses (label_ref ...) without a mode. This means
that any LABEL_REFs generated from .md file expanders or splitters will
use VOIDmode.
For LABEL_REFs generated via explicit gen_rtx_LABEL_REF, usage seems to
be mixed between using VOIDmode and Pmode in target C++ files. Common
code does seem to be using always Pmode, as far as I can see.
Are LABEL_REFs in fact supposed to always have Pmode?
Bye,
Ulrich
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com