[llvm] [DA] Dependence analysis does not handle array accesses of different sizes (PR #116630)

[Sebastian Pop via llvm-commits]

sebpop wrote:

> Looking a bit more closely, I'm not sure that "different access sizes" is really the core issue here.
> 
> [...] the code does not verify that the access sizes and the access stride are compatible.

This is more difficult to solve.  Please see separate patch https://github.com/llvm/llvm-project/pull/123436 that describes the issue.  DA is a symbolic solver that needs to collect a set of assumptions under which the DA produces correct results.  We need to implement something similar to what Polly does in collecting a set of symbolic constraints, and those get generated as a runtime test versioning the loops generated by Polly. 


https://github.com/llvm/llvm-project/pull/116630