[llvm] [AA][ScopedNoAliasAA] Returns ModRef when an alias exists (PR #70159)

[via llvm-commits]

DianQK wrote:

> It's sufficient to have !noalias on one instruction and !alias.scope on the other. You don't need both of them to have !noalias and !alias.scope.
> 
> See https://llvm.org/docs/LangRef.html#noalias-and-alias-scope-metadata for documentation and in particular:
> 
> > When evaluating an aliasing query, if for some domain, the set of scopes with that domain in one instruction’s alias.scope list is a subset of (or equal to) the set of scopes for that domain in another instruction’s noalias list, then the two memory accesses are assumed not to alias.

Thanks, I get it. I'll keep looking for what the problem is.

https://github.com/llvm/llvm-project/pull/70159