TimNN added a comment. I'm still trying to properly minimize this, but this definitely interacts badly with other optimizations (which triggers the Rust CI failure I mentioned above):
- We start with two functions, `outer` and `inner`. `outer` calls `inner`. `outer` has a `noundef` argument that it forwards to `inner` (where the argument is also `noundef`). - `PostOrderFunctionAttrsPass` decides, for both functions, that the argument is `readnone`. The `readnone` attribute is //only// added to the function definitions. The `readnone` attribute is //not// added at the `call` to `inner` from `outer`. - The `DeadArgumentEliminationPass` decides that when `outer` calls `inner` the argument should be `poison`. - This patch sees the `poison` being passed to a `noundef` argument and kills the call. I don't know which component should be considered "at fault" here (or if the `readnone` bit is even relevant). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D133036/new/ https://reviews.llvm.org/D133036 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
