[PATCH] D33362: [Polly][WIP]JSCoP Importer: support for multi-valued schedules

[Michael Kruse via Phabricator via llvm-commits]

Meinersbur added a comment.

In https://reviews.llvm.org/D33362#761968, @Mike_Jongen wrote:

> In https://reviews.llvm.org/D33362#760795, @Meinersbur wrote:
>
> > Comment at: lib/Exchange/JSONExporter.cpp:364
> >
> > `isl_union_map_lexmin` can fail if the input is not lower-bounded. Could you add a check/assertion?
>
>
> Not sure if I understand. How can I check this, is there a function for this?


Depending on the on_error setting, isl_union_map_lexmin prints a warning, abort()s, and/or returns nullptr. You can e.g. assert on that the result value is not null.

You can check in advance using isl_basic_map_image_is_bounded. However, recently there was a discussion in isl-dev that this is not a sufficient condition. It should still suffice for us because if the map is not bounded, the lexmin/subtract cycle will loop endlessly, so such an assert would warn about this.

Run `ninja/make polly-update-format` to get the whitespace correct.

Looking forward to see a test case. One for verifying the behavior when passing an unbounded map (e.g. `{ Stmt[i] -> [j] : j >= i }`) would be great as well.


https://reviews.llvm.org/D33362