[LLVMdev] SIV tests in LoopDependence Analysis, Sanjoy's patch

[Hal Finkel]

On Mon, 14 May 2012 11:46:02 -0700
Preston Briggs <preston.briggs at gmail.com> wrote:

> On Sat, Apr 21, 2012 at 6:08 AM, Sanjoy Das
> <sanjoy at playingwithpointers.com> wrote:
> >
> > Sorry for having been quiet for so long, I have my university exams
> > going on, and will be able to contribute only after the coming
> > Friday.
> 
> Gents,
> 
> While you've been fooling around with exams, I have been focused with
> laser-like intensity, or something...
> Here are new versions of 4 SIV tests:
> 
>    - the Strong SIV test:
>    https://sites.google.com/site/parallelizationforllvm/strong-siv-test
>    - the Weak-Zero SIV test:
>    https://sites.google.com/site/parallelizationforllvm/weak-zero-siv-test
>    - the Weak-Crossing SIV test:
>    https://sites.google.com/site/parallelizationforllvm/weak-crossing-siv-test
>    - the Exact SIV test:
>    https://sites.google.com/site/parallelizationforllvm/weak-siv-test
> 
> and our first MIV test:
> 
>    - the RDIV test:
>    https://sites.google.com/site/parallelizationforllvm/rdiv-test

Can you explain this comment:
> With minor algebra, this test can also be used for things like [c1 +
> a1*i + a2*j][c2].

> 
> If you have any thoughts about this code, I'd be very interested in
> hearing them.

I this look good, but, as you say below, we also need to work on the
top-level infrastructure. It will be hard to validate and evaluate
this code without a framework in which to use it.

One thing that I would like to mention is that 'use' here should also
include user feedback. This means being able to pass information back
to the frontends about which loops are being effectively analyzed, and
for loops that are not, why not.

 -Hal

> 
> I'm going to take a break from working on these low-level tests and
> spend some time working top-down on the high-level structure of the
> Delta Test (finding coupled subscripts, etc).
> 
> Preston



-- 
Hal Finkel
Postdoctoral Appointee
Leadership Computing Facility
Argonne National Laboratory