uabelho added a comment. In D92270#2422625 <https://reviews.llvm.org/D92270#2422625>, @aqjune wrote:
> Hi, > > It seems it is related to two optimizations: > (1) `select i1 x, true, y` -> `or i1 x, y` > (2) `or i1 x, poison` -> `poison` > > Semantically, the first one is broken. It needs to freeze y. But, it will > introduce a lot of freeze instructions. The clang patches that introduce > noundef to function arguments is still ongoing. > Another workaround is to weaken (2) to `or i1 x, poison` -> `x`. This fixes > the miscompilation; I'll push a commit that does this. Should langref also be updated to describe this? Or does it already? I just found this "An instruction that depends on a poison value, produces a poison value itself.". Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D92270/new/ https://reviews.llvm.org/D92270 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
