how to handle the tuple longer than 36 or higher?

[wujilingfeng]

I need to handle longer arrays, and I found that the tuple didn't support it. Even if the tuple can support it,, It would be too much trouble to do so.
it seems that Exp [Float] is better to do it, But it's also unsupported.

Acc vector seems inappropriate，Because many functions need parameters like Exp a->Exp b

[tmcdonell]

The idea is that you have arrays of data (in Acc) and then you perform some (parallel) operation over the elements in those arrays, where the functions on the individual elements are of that Exp type.

If you think about the map function for example, the array data is stored in Acc, and the operation to apply to each element of the array is (as you saw) a function Exp a -> Exp b.

But maybe if you tell us a bit more about what you are trying to do we can give some more specific/helpful advice?

[wujilingfeng]

I was wirting sift algorithm, every feature point has many directions.

[tmcdonell]

But in your implementation is "many" a statically known number, or does it vary per feature?

[wujilingfeng]

But in your implementation is "many" a statically known number, or does it vary per feature?

It vary per feature.

[tmcdonell]

Maybe the expand function that David mentioned would work for you then. This is getting into the realm of irregular data-parallelism, which is much more difficult to execute in parallel... I'm interested to know what other features could help here!

(To answer your earlier question, one concrete reason we don't support something like Exp [Float] is simply that individual threads on the GPU can not allocate memory, so there is no way to build that list dynamically. Even if they could, then there is the problem of where in memory the (thousands of) threads should decide (in parallel) to store their results.)

[wujilingfeng]

Thank you! I think there are many indirect ways to solve it .