asm compilation error on aarch64/s390x/ppc64le

[luizirber]

Hi!

Today I published two Rust packages mentioned in #61 to crates.io:
https://crates.io/crates/bitmagic
https://crates.io/crates/bitmagic-sys
(let me know if you want to be added as owner, BTW).

I'm using these packages in sourmash-bio/sourmash#1221, and the detail is that we build Python wheels (the binary format for Python packages) for the manylinux-supported platforms: aarch64, s390x and ppc64le. But, when I tried to build the wheels, compilation failed with errors in

BitMagic/lang-maps/libbm/src/libbm_impl.cpp

Line 57 in 6821963

asm volatile("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (1));

like

impossible constraint in 'asm':
     asm volatile("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (1));

I'm adding CI to test in these platforms in https://github.com/luizirber/bitmagic-rs/, and here is a similar error log:
https://github.com/luizirber/bitmagic-rs/pull/2/checks?check_run_id=2153526751#step:4:435

Considering the surrounding code, it is failing due to none of these platforms having SIMD, which makes sense, but... I don't know how to disable these checks in the places I can control externally (cmake defines). Any tips/suggestions on how to achieve that?

Thanks!

P.S: saying "we don't support these platforms" is totally fine too, I kind of started building s390x and ppc64le wheels just because I tested it once and it worked for sourmash at that point. I do know about some ppc64le users, but the benefits we get from bitmagic are way too good and are making me considering dropping them.