[clang] [CIR] Recognize loop interchange candidates (PR #210847)

[Andy Kaylor via cfe-commits]

https://github.com/andykaylor commented:

This looks like a good start.

It would be useful to have an option to emit verbose remarks that included why loops are rejected as candidates. That would also improve the test.

Before proceeding with implementation there are some additional things you'd need to check for legality. The one that jumped out at me is that you need to check for operations with side effects and potentially aliasing memory accesses.

https://github.com/llvm/llvm-project/pull/210847