Re: push parser implemenation

[Bob Rossi]

On Mon, Apr 10, 2006 at 03:44:07PM -0400, Bob Rossi wrote:
> On Sat, Apr 08, 2006 at 02:58:45PM -0400, Bob Rossi wrote:
> > On Fri, Apr 07, 2006 at 02:42:29PM +0200, Akim Demaille wrote:
> > > Bob,
> > > 
> > > I'm starting to toy with your implementation, and to try to bench it.
> > > It seems that there is about a 15% performance loss of push.c compared
> > > to yacc.c, both used in pull mode without compiler optimization on my
> > > Mac.
> > 
> > You know, it would be possible to only create the structure for the push
> > parser mode, and to leave all variables declared in yyparse for normal
> > mode and for pure mode. This would be more m4 magic, but would fix the
> > performance problems.
> > 
> > I wrote it the way it is now because it was cleaner. I only had to do m4
> > magic for 'pv->yychar' vs 'yychar' for the 4 user visible variables
> > (instead of all the variables), because all 3 versions used the structure.
> > 
> > What do you think?
> 
> Is this something I should do?

Hi everyone, I hope I can get some suggestions soon. I don't want this
to be forgotten about. 

Either we can make the push parser a separate file, we can allow the
user to loose the 10% speed performance, I can attempt to do the above
suggestion, or

I can see what happens if I declare the struct globally, and when in
push-yacc and pure-yacc mode, declare variables on the stack with the
same name as the struct's fields. This may improve the speed.

Any of these ideas sound good?

Thanks,
Bob Rossi