Hi, On 2020-11-02 10:28:33 -0800, Jesse Zhang wrote: > On Thu, Oct 15, 2020 at 6:12 PM Andres Freund <and...@anarazel.de> wrote: > > There will be a breaking API change for JIT related API in LLVM > > 12. Mostly about making control over various aspects easier, and then > > building on top of that providing new features (like JIT compiling in > > the background and making it easier to share JIT compiled output between > > processes). > > > > I've worked with Lang Hames to ensure that the new C API has feature > > parity... > > > > I assume you're alluding to the removal of ORC legacy (v1) API?
Yes. > How far back was feature parity in the new API, or we could only switch > starting > with LLVM 12? Parity is in 12 only - I had to work with Lang for a while to get to parity. There really is no reason to switch earlier anyway. > > The postgres changes are fairly localized, all in llvmjit.c - it's just > > a few #ifdefs to support both LLVM 12 and before. > > > > The two questions I have are: > > > > 1) Which versions do we want to add LLVM 12 support? It'd be fairly > > easy to backport all the way. But it's not quite a bugfix... OTOH, > > it'd probably painful for packagers to have dependencies on different > > versions of LLVM for different versions of postgres. > > > > 2) When do we want to add LLVM 12 support? PG will soon stop compiling > > against LLVM 12, which will be released in about 6 months. I worked > > with Lang to make most of the breaking changes in a branch (to be > > merged in the next few days), but it's possible that there will be a > > few smaller changes. > > I think this has already happened about two weeks ago when Lang's commit > 6154c4115cd4b78d landed in LLVM master. Yea, I just need to polish the support a bit more. Shouldn't be too much more work (right now it has too much unnecessary duplication, need to split some reindation out into a separate commit). https://github.com/anarazel/postgres/commits/llvm-12 Greetings, Andres Freund
