[llvm] [SROA] Use SmallPtrSet for PromotableAllocas (PR #105809)

[Bartłomiej Chmiel via llvm-commits]

b-chmiel wrote:

> Pretty sure this is going to cause non-determinism, e.g. because mem2reg will insert phi nodes in different order. You'd need a set container with stable order like SetVector -- though I think that one doesn't actually have efficient erase.

Thanks for pointing it out. I'd tried previously SmallSetVector, but it wasn't efficient enough.


> > You'd need a set container with stable order like SetVector -- though I think that one doesn't actually have efficient erase.
> 
> Maybe `SetVector<T, std::deque<T>>` can be used?

Thanks, I'll try this data structure out and promptly report back with results.

https://github.com/llvm/llvm-project/pull/105809