Stream: compiler development

Topic: bitcode backwards compatibility in zig's llvm builder

alexrp (Feb 22 2025 at 06:12):

hi folks, just wanted to check to what degree roc cares about producing backwards compatible bitcode using zig's llvm.Builder api?

context: discussion on https://github.com/ziglang/zig/pull/22903

Sam Mohr (Feb 22 2025 at 06:13):

That's probably a @Brendan Hansknecht question

Brendan Hansknecht (Feb 22 2025 at 06:38):

I think we are in the same boat as you all. Bitcode backwards compatibility could be nice to have, but it is not particularly important. Changes in llvm over the years (like correct handling of i128 alignment) mean that older versions of llvm will lead to miscompilation anyway.

Brendan Hansknecht (Feb 22 2025 at 06:40):

So yeah, progress and bug fixes are more important than trying to use old versions of llvm.

Andrew Kelley (Feb 24 2025 at 02:04):

I'll probably take Meghan's suggestion and put it in the std lib. If it already works well enough out of the box, great, otherwise I suggest the standard workflow of:

• Fork (copy impl to your repo)
• Patch your fork
• Send patch upstream
• Delete fork on next upstream release

Brendan Hansknecht (Feb 24 2025 at 02:09):

Sounds great

alexrp (Feb 24 2025 at 11:39):

https://github.com/ziglang/zig/pull/23000

Last updated: Jul 26 2025 at 12:14 UTC