People reported challenges building V8 (whether upstream or the Node.js variant) on s390x with z13 support. I don't know if it was discussed on the porters mailing list because it's not public: https://groups.google.com/g/v8-s390-ports
Thanks for sharing. The first link seems non public indeed.
I can imagine there is some compile issue we could reasonably fix, with the help of someone who has Z13 access. Please encourage them to raise an issue. I will be back on May 26.
After that, it should at least be able to use the scalar fallback.
The issue with Z14 is that it lacks fp32 support. Would their usage be integer only?
I'll bring it up with some folks. It probably won't change much because the z13 transition has finished by now. It's still good to know because RISC-V is in the same boat regarding Highway support today: we need scalar fallback in Highway until we get RVA23 hardware deployed.
Elsewhere, some people interpreted https://github.com/google/highway/issues/1895 as meaning that Highway code does not work on z13 at all.