error: inline assembly requires more registers than available

[pgrinaway]

Hi all,

Thanks for the great project. I'm trying to compile it on a 2018 Macbook Pro, and I keep getting the following error:

error: inline assembly requires more registers than available

error: could not compile `halo2curves` (lib) due to 1 previous error

even when I try cargo build --release --features portable. Interestingly, debug mode does not cause this problem and everything succeeds. Is there something else I should do to prevent emission of unsupported assembly?

At the same time, trying to compile on a linux box, compilation succeeds, but the lurk repl immediately fails with an illegal instruction. I suspect I am failing to disable some kind of unsupported optimization, but does anyone have any pointers? In this second case, even debug mode results in the illegal instruction. Any thoughts?

[huitseeker]

even when I try cargo build --release --features portable. Interestingly, debug mode does not cause this problem and everything succeeds. Is there something else I should do to prevent emission of unsupported assembly?

This is about halo2curves' assembly generation: https://github.com/privacy-scaling-explorations/halo2curves/blob/main/Cargo.toml#L49

This is only activated if one imports arecibo with the non-default asm feature:
https://github.com/lurk-lab/arecibo/blob/5268c2084821955c5953c29c7e179b2052523b5d/Cargo.toml#L116

Which happens here in your case because your 2018 Mac is on x86_64:
https://github.com/lurk-lab/lurk-rs/blob/8802da5c85d26129167c3ba7ef4e7ed22f56707a/Cargo.toml#L72-L73

So I guess this is about modifying the flag
[target.'cfg(target_arch = "x86_64")'.dependencies]
into
[target.'cfg(and(target_arch = "x86_64", not(target_os = "macos")))'.dependencies]

Can you try that and tell me if it works for you?

[pgrinaway]

Hi, thanks for the fix. I changed the line you mentioned to these two:

[target.'cfg(all(target_arch = "x86_64", not(target_os = "macos")))'.dependencies]
nova = { workspace = true, features = ["asm"] }
[target."cfg(all(target_arch = \"x86_64\", target_os = \"macos\"))".dependencies]
nova = { workspace = true }

And the build works. I think the syntax uses all rather than and and I needed to add another target for x86 + macos.