This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: pr26026: udiv and umod optimization

From: Alan Modra <amodra at bigpond dot net dot au>
To: Paul Brook <paul at codesourcery dot com>
Cc: gcc-patches at gcc dot gnu dot org, Andrew Haley <aph at redhat dot com>, Andrew Pinski <pinskia at physics dot uc dot edu>
Date: Sat, 4 Feb 2006 11:40:40 +1030
Subject: Re: pr26026: udiv and umod optimization
References: <17379.30955.436649.904253@zapata.pink> <200602031549.k13Fnjdf003769@earth.phy.uc.edu> <17379.32393.912056.801361@zapata.pink> <200602031610.28480.paul@codesourcery.com>

On Fri, Feb 03, 2006 at 04:10:26PM +0000, Paul Brook wrote:
> > Can we be sure that this assumption is safe in _all_ the languages
> > that gcc supports?  I get worried when C-isms creep into generic
> > optimizers.
> 
> I think we already make this assumption in other places, not least when 
> expanding to RTL.

Yes, see expmed.c:expand_divmod where the analogous case of unsigned div
or mod by a constant power of two is simplified.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre

References:
- Re: pr26026: udiv and umod optimization
  - From: Andrew Haley
- Re: pr26026: udiv and umod optimization
  - From: Andrew Pinski
- Re: pr26026: udiv and umod optimization
  - From: Andrew Haley
- Re: pr26026: udiv and umod optimization
  - From: Paul Brook

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]