From: Oleg Endo <oleg.endo@t-online.de>
To: Hans-Peter Nilsson <hp@bitrange.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>, gcc-patches@gcc.gnu.org
Subject: Re: [RFC, ivopts] fix bugs in ivopts address cost computation
Date: Sun, 10 Jun 2012 17:51:00 -0000 [thread overview]
Message-ID: <1339345901.2300.30.camel@yam-132-YW-E178-FTW> (raw)
In-Reply-To: <alpine.BSF.2.00.1206082206380.40943@dair.pair.com>
On Fri, 2012-06-08 at 22:33 -0400, Hans-Peter Nilsson wrote:
> On Tue, 5 Jun 2012, Sandra Loosemore wrote:
>
> > (1) While the address cost computation is assuming in some situations
> > that pre/post increment/decrement addressing will be used if
> > supported by the target, it isn't actually using the target's address
> > cost for such forms -- instead, just the cost of the form that would
> > be used if autoinc weren't available/applicable.
>
> There are lots of bugzilla entries complaining about bad
> autoinc/dec generation. Maybe your patch solves some of them?
>
I've tried some of the cases mentioned in
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50749
with Sandra's patch applied. Unfortunately it didn't help much. There
seem to be other things going wrong with auto-inc-dec.
BTW, auto-inc-dec uses 'set_src_cost' in 'attempt_change' to determine
the address costs. At least the SH target will not respond to that
properly. I was thinking of adding something to sh_rtx_costs to invoke
sh_address_cost as a fix for that, but on the other hand I was wondering
why the target's address cost function isn't used in auto-inc-dec
directly ...
Cheers,
Oleg
next prev parent reply other threads:[~2012-06-10 16:32 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-05 16:39 Sandra Loosemore
2012-06-06 8:45 ` Richard Guenther
2012-06-06 11:48 ` Zdenek Dvorak
2012-06-13 19:57 ` Sandra Loosemore
2012-06-09 2:58 ` Hans-Peter Nilsson
2012-06-10 17:51 ` Oleg Endo [this message]
2012-06-10 17:58 ` inc-dec (was: Re: [RFC, ivopts] fix bugs in ivopts address cost computation) Hans-Peter Nilsson
2012-06-10 18:39 ` Oleg Endo
2012-07-04 16:35 ` [PING] Re: [RFC, ivopts] fix bugs in ivopts address cost computation Sandra Loosemore
2012-07-17 11:22 ` Richard Guenther
2012-07-25 19:39 ` Sandra Loosemore
2012-07-25 19:46 ` William J. Schmidt
2012-07-06 2:44 ` Jiangning Liu
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