Ben Lever Ben.Lever at
Tue Aug 10 20:15:46 EDT 2010

Hi Manuel,

Of course, in the future we would require larger stencils (e.g. 36x36 in AutoMap) to be supported. Is there a penalty for using tuples to specify stencil patterns when the stencil size is large? Had you envisaged an upper limit to stencil size?

Large tuples are tedious because —in principle— each argument of a tuple could be of a different type.  That capability is not used by stencils (where all arguments are of the element type of the source array).  However, in order to do the reflection of the EDSL, we need a datatype where the type fixes the size of the structure — that is the case for tuples, where the arity of the type matches the arity of the values.  To support larger stencils conveniently, we ideally need a datatype that constrains all elements to be of the same type (like an array) *and* where the size is explicit in the type (like with a tuple) — ie, we want a form of statically sized array.

Ok - that makes sense.

I'm sure we can work that out, but it keeps matters simpler if we can do that at a later point (after we have small stencils and sharing efficiently implemented).

We're happy with that approach - get everything working with tuples first then look at a new data type later that can support larger stencils more effectively.


Ben Lever
Senior Researcher Engineer
National ICT Australia

NICTA l Locked Bag 9013 l Alexandria NSW 1435
T + 612 8306 0742 | F +612 9376 2027<> l ben.lever at<mailto:ben.lever at>

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