Fix GPU addressing bug

While working on BFS discovered a bug in the address computations for the GPU backend when dealing with arrays of products.

Discovered a few issues that were causing this

1. The size of the element type of an array was not being put in parentheses leading to very weird computations
2. Offsets into a record were not being computed correctly (there was an unnecessary subtraction)
3. Offsets into a record were not being generated in code
4. When processing indices the type of the current collection was not being updated which is necessary to properly compute sizes
5. (Actually unrelated, but noticed it) Sizes of arrays were not being computed properly, it was using get_alignment as the element size rather than get_size.

See comments for some questions I have related to extra_dim_collects.

requested review from @rarbore2

assigned to @aaronjc4

I'm not 100% certain what the extra_dim_collects are, but I assume it's related to collections that we add extra dimensions to collect the results from each GPU thread (or something similar).

If that's the case, I suspect it should only be considered when we're looking at a "top-level" type, in particular therefore when computing sizes in get_size recursive calls would always get None for this argument, and I think in codegen_collect again only at the top-level collection would we pass in the provided value, on subsequent indices it should pass None to get_size.

Wow, thanks for catching this!

resolved all threads

approved this merge request

added 1 commit

• cd96d833 - Remove extra_dim_collects

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enabled an automatic merge when all merge checks for cd96d833 pass

merged

mentioned in commit 4ceecb94