[flang-commits] [flang] [Flang][OpenMP] Add Semantics support for Nested OpenMPLoopConstructs (PR #145917)

[Jan Leyonberg via flang-commits]

jsjodin wrote:

I have a question about nested loop constructs and checking the legality of combining them. For example doing full unrolling and then tiling would be illegal since if a loop is unrolled there is nothing to tile. Another example that I ran into is collapse and tiling, since collapse assumes independent loops, but only the outer loops after tiling are independent. At some point in the front-end there has to be a checker that makes sure that the nested loop constructs are legal and can report meaningful error messages if they are not. Do you have any ideas how this can be done? Maybe a separate pass would be required that somehow tracks certain properties about the resulting loops that are created from a transform?

https://github.com/llvm/llvm-project/pull/145917