This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: patch: subreg of mem when converting vector types
- To: Aldy Hernandez <aldyh at redhat dot com>
- Subject: Re: patch: subreg of mem when converting vector types
- From: Jan Hubicka <jh at suse dot cz>
- Date: Sat, 3 Nov 2001 17:35:03 +0100
- Cc: Geoff Keating <geoffk at redhat dot com>, gcc patches <gcc-patches at gcc dot gnu dot org>
- References: <1004575206.30169.222.camel@litecycle.cc.andrews.edu> <jmpu73p57p.fsf@geoffk.org> <1004588887.30176.234.camel@litecycle.cc.andrews.edu>
>
> > Wouldn't it create more efficient code if instead simplify_subreg was
> > always called afterwards? It would save a (perhaps unnecessary) copy
> > to a register.
>
> i was just following the precedent in store_bit_field() which does
> exactly what my code does (copy to a reg).
It is not so long since i've implemented the simplify_subreg stuff.
In general I would love to see the compiler use it whenever possible instead
of doing even trivial transforamtions by hand. It brings more flexibility
into the nasty subreg issues.
I've searched and fixed number of places, but some are still pending.
Perhaps, can you just fix the store_bit_field to use the simplify_subreg
too?
Honza
>
> i think this is not a common case, so we could afford to just copy to a
> register.
>
> it's your call. imo, either way is fine.
>
> lemme know so i can come up with a patch.
>
> aldy