[PING] lfloor/lceil and rint SSE expansion for x86_64/i?86

Jan Hubicka hubicka@ucw.cz
Tue Oct 31 17:05:00 GMT 2006


> On Sun, 29 Oct 2006, Jan Hubicka wrote:
> 
> > > 
> > > On Sun, 29 Oct 2006, Richard Guenther wrote:
> > > > [PATCH][4.3] Expand lfloor/lceil inline for x86_64/i?86 SSE math
> > > > http://gcc.gnu.org/ml/gcc-patches/2006-10/msg00912.html
> > > 
> > > This is OK for mainline.
> > > 
> > > > [PATCH][4.3] Expand rint inline for x86_64/i?86 SSE math
> > > > http://gcc.gnu.org/ml/gcc-patches/2006-10/msg00987.html
> > > 
> > > As is this.
> > 
> > Hi,
> > this patch seems to noticeably increase memory consumption.  Perhaps
> > setup cost of optabs?
> 
> Probably.  Though I wouldn't call it significantly.

It seems rather significant to me (there is about 8% increase I didn't
sent mail about), mainly because it affect the constant startup cost of
compiler and we significantly slowed down compiling empty file in recent
years.
I completely agree with Roger that using machine generated function (or
simply drop all the tripples into one hashtable, there are about 400
defined optabs for i386) is a lot better way to go.

Honza
> 
> Richard.
> 
> --
> Richard Guenther <rguenther@suse.de>
> Novell / SUSE Labs



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