Re: [Autovect]dependencies of virtual defs/uses

["Jiahua He" <jiahua at gmail dot com>]

Oh, I see. For reduction and induction, you don't need to deal with
the condition with vdef. I am considering how to implement an idiom
with vdef, like SCAN (prefix sum). And by the way, do you support
idioms with vuses?

Jiahua


2007/2/12, Dorit Nuzman <DORIT@il.ibm.com>:
> > Thanks! In fact, I should ask how to deal with idiom (such as
> > reduction, induction) recognition for virtual defs/uses.
> >
>
> Just curious - what is this for? (are you interested in this in the context
> of vectorization? is there a specific example you have in mind?)
>
> dorit
>
> > Jiahua
> >
> >
> > 2007/2/12, Daniel Berlin <dberlin@dberlin.org>:
> > > On 2/12/07, Jiahua He <jiahua_he@ustc.edu> wrote:
> > > > Hi,
> > > >
> > > > I am reading the code of autovect branch and curious about how to
> deal
> > > > with the dependencies of virtual defs/uses. In the function
> > > > vect_analyze_scalar_cycles( ), I found the statement "Skip virtual
> > > > phi's. The data dependences that are associated with virtual
> defs/uses
> > > > ( i.e., memory accesses) are analyzed elsewhere." But where is the
> > > > code? I tried to search  for "vect_induction_def" and
> > > > "vect_reduction_def" and found that they are not used to assign
> > > > elsewhere. Is the analysis not implemented yet? Thanks in advance!
> > >
> > > They show up as data references because of tree-data-reference.c
> > marking them.
> > > At lets, that's how other linear loop transforms handles it.
> > > Not sure about how vectorizer deals with it specifically
> > >
> > > >
> > > > Jiahua
> > > >
> > >