[PATCH] D32401: [Devirtualization] insert placement new barrier with -O0

[Piotr Padlewski via Phabricator via cfe-commits]

Prazek added a comment.



In https://reviews.llvm.org/D32401#734870, @rjmccall wrote:

> Won't you have the exact same problem when LTO'ing with code that wasn't compiled with strict v-table pointers?


No, because we fire error when combining module compiled with and without StrictVtablePointers

In https://reviews.llvm.org/D32401#734879, @mehdi_amini wrote:

> > To not break LTO with different optimizations levels, we should insert the barrier regardles of optimization level.
>
> What do you mean by "break"? Is it a correctness issue?


Yes, if we would combine module with barriers and without. 
You can check out this commit: https://reviews.llvm.org/D12580


https://reviews.llvm.org/D32401