[llvm] LangRef: storing poison in memory is UB (PR #141339)

[Nikita Popov via llvm-commits]

nikic wrote:

Interesting idea.

> It still preserves poison in most cases, so that SROA does not need to insert freezes.

This model avoids freeze for plain store to load forwarding (as the store can only be fully poison), but isn't freeze in SROA still necessary for all the overlapping cases (which lower via integer widening)?

https://github.com/llvm/llvm-project/pull/141339