[llvm] [SROA] Allow rewriting memcpy depending on tbaa.struct (PR #77597)

[Bruno De Fraine via llvm-commits]

brunodf-snps wrote:

> I did not investigate why (I probably need a much smaller test case for that). I know that we do use `-Xclang -new-struct-path-tbaa`, perhaps the TBAA metadata format is different.

I looked into this a bit, and I see no `tbaa.struct` metadata on the relevant `llvm.memcpy` calls in my case. I think this may be because this is a struct with inheritance and base classes.

There seems to be no `tbaa.struct` metadata generated for a struct with a base: https://godbolt.org/z/dc1K3b4Pv ?


https://github.com/llvm/llvm-project/pull/77597