[flang] [llvm] [llvm] Improve llvm.objectsize computation by computing GEP, alloca a… (PR #117849)

[via llvm-commits]

serge-sans-paille wrote:

@fmayer I think I fixed the issue we've been discussing in the previous attempt (there was a typo in the phi node handling), would you mind giving this PR a try? thanks!

https://github.com/llvm/llvm-project/pull/117849