[Mlir-commits] [flang] [mlir] [RFC][mlir] ViewLikeOpInterface method for detecting partial views. (PR #164020)

[Slava Zakharin]

vzakhari wrote:

Here is what I have in the latest commit:
```
Fixed LocalAliasAnalysis to return PartialAlias instead of MustAlias
in more cases. There are still cases where LocalAliasAnalysis
incorrectly returns MustAlias (see mlir/test/Analysis/test-alias-analysis.mlir).

Also see a NOTE in flang/test/Analysis/AliasAnalysis/ptr-component.fir,
where combining LocalAliasAnalysis result (PartialAlias) and FIR AliasAnalysis
result (NoAlias) results in PartialAlias, which is more conservative than
the previous NoAlias result. It is unclear how to address this case,
given the merging rules for multiple alias analyses' results.
```

I tried not to change the current LocalAliasAnalysis implementation too much. There are still cases where it incorrectly reports MustAlias instead of PartialAlias. Moreover, the order of visiting affects whether MustAlias or PartialAlias is returned.

@River707 do you have any comments?

https://github.com/llvm/llvm-project/pull/164020