Erik de Castro Lopo
Reid Barton wrote:
Why do we need to revert anything, can't we just make a one-character fix of 3.6 to 3.5 on the ghc-7.10 branch?
Even with that one character change the LLVM detection is not complete or correct. Specifically, building the compiler will enforce the right llvm version, but the binary-dist configure script just uses "llc" and "opt".
Furthermore, I am pretty sure that #10292 is causes by llvm-3.5 and that if we use llvm-3.6 buildng on Arm works. Unfortunately building and testing on Arm takes a long time and I am still in the process of verifying this.
While I would love to see LLVM 3.6 rolled out soon as a GHC target (it is substantially more stable on ARM in my experience) I agree that doing this for 7.10.2 would be a bit of a large change for a minor release. If nothing else it would be surprising for users to find that their previously working LLVM/GHC combination needed to be upgraded upon moving to 7.10.2. In my experience LLVM 3.5 works reasonably well on ARM; it seems like this should be sufficient to carry us through to 7.12. Cheers, - Ben