[PATCH] D55969: [BasicAA] Fix AA bug on dynamic allocas and stackrestore

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

I guess stackrestore is special because it's the only way to clobber an unescaped alloca; I think this is fine, in that sense.

That said, I wish IR was defined in a more consistent way; I'm concerned that there are probably other places in LLVM that are making similar bad assumption about dynamic allocas.  Since VLAs are essentially banned from most codebases, we get very little test coverage on Linux.  I'm particularly concerned about places using PointerMayBeCaptured and similar logic.  Is LICM safe?  Is DSE safe?  Is AAResults::callCapturesBefore safe?  Is InstCombiner::foldAllocaCmp safe?  Is TailRecursionElimination safe?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55969/new/

https://reviews.llvm.org/D55969