​​The regions problem
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​Problem

​​With the current “limitation” that stages can only have global extents, we need to lie about extents:
  • ​​The extent of this stage should be something different from [10, 10, 0, 0]​, because we’re otherwise not hitting all the relevant points
  • ​​The first solution to this was to use make_stage_with_extent​ and set them to 0, as we do not need to extend the domain ever
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​GridTools and the execution model

  • ​​Multistages are only a container for stages with a direction, no sync required
  • ​​see point about fusion in previous discussion
  • ​​stages get internally fused if the extents allow for it
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​Forced synchronization in GridTools

  • ​​only possible by either not lying about the extents or by multiple computations
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​Consequences

  • ​​temporaries used in two multistages need to become full fields that have the 3d domain allocated (versus block-local [extended] memory) → promotion internally works
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