From: Ralf Jung Date: Mon, 11 Apr 2022 21:37:44 +0000 (-0400) Subject: link to new LLVM bugtracker X-Git-Url: https://git.ralfj.de/web.git/commitdiff_plain/9976b8275788d7d6ef356517d5bf4fd36a82efd5 link to new LLVM bugtracker --- diff --git a/personal/_posts/2022-04-11-provenance-exposed.md b/personal/_posts/2022-04-11-provenance-exposed.md index 56c7f8f..317cc30 100644 --- a/personal/_posts/2022-04-11-provenance-exposed.md +++ b/personal/_posts/2022-04-11-provenance-exposed.md @@ -419,7 +419,7 @@ I discussed above how my vision for Rust relates to the direction C is moving to What does that mean for the design space of LLVM? Which changes need to be made to fix (potential) miscompilations in LLVM and to make it compatible with these ideas for C and/or Rust? Here's the list of open problems I am aware of: -- LLVM needs to stop [removing `inttoptr(ptrtoint(_))`](https://bugs.llvm.org/show_bug.cgi?id=34548) and stop doing [replacement of `==`-equal pointers](https://bugs.llvm.org/show_bug.cgi?id=35229). +- LLVM needs to stop [removing `inttoptr(ptrtoint(_))`](https://github.com/llvm/llvm-project/issues/33896) and stop doing [replacement of `==`-equal pointers](https://github.com/llvm/llvm-project/issues/34577). - As the first example shows, LLVM also needs to treat `ptrtoint` as a side-effecting operation that has to be kept around even when its result is unused. (Of course, as with everything I say here, there can be special cases where the old optimizations are still correct, but they need extra justification.) - I think LLVM should also treat `inttoptr` as a side-effecting (and, in particular, non-deterministic) operation, as per the last example. However, this could possibly be avoided with a `noalias` model that specifically accounts for new kinds of provenance being synthesized by casts. (I am being vague here since I don't know what that provenance needs to look like.)