This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [rfc] multi-word subreg lowering pass
- From: Björn Haase <bjoern dot m dot haase at web dot de>
- To: Ian Lance Taylor <ian at airs dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Thu, 1 Jun 2006 12:06:46 +0200
- Subject: Re: [rfc] multi-word subreg lowering pass
- References: <Pine.LNX.4.44.0605280835280.26534-100000@www.eyesopen.com> <m3verk3f7q.fsf@gossamer.airs.com>
Ian Lance Taylor wrote on Donnerstag, 1. Juni 2006 20:26 :
> I've also been working on this. I'm currently running a version of
> RTH's lower-subreg pass twice, once early and once after splitting
> instructions.
Would it be possible to sketch with a few lines what you needed to do in order
to get the lowering working after splitting (i.e. despite the newly inserted
pseudos)?
That would be very helpful for me for evaluating the possible benefit for the
AVR target. Right now, I am maybe 30% through with converting the AVR backend
to CCmode and with using splitting patterns instead of the lowering at text
output. Evaluating what could come out after smashing all the QImode and
HImode subregs that I get after the splitting would be very interesting.
Right now, I could only make guesses since gcc will crash as soon as I try to
make RTH's original pass run after split1. I think this is due to the
inserted new pseudos.
Bjoern.