build: fix osx build

[anonkey]

Hi,
i hade some trouble to build on mac os aarch64, needed some small fixes.
Moreover --no-default-feature wasn't working for full workspace build i replaced it for cfg() directive in cargo.toml to rely on sse4.2 feature presence

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[Wonshtrum]

Hi! Sorry for the late answer.
Thanks for your interest in Sozu! The PR seems great, we never took the time to integrate SIMD into the build properly.
But I'm confused, your configuration seems backward:

[target.'cfg(not(target_feature = "sse4.2"))'.dependencies]
kawa = { version = "^0.6.6" } # kawa default is to use SSE

[target.'cfg(target_feature = "sse4.2")'.dependencies]
kawa = { version = "^0.6.6", default-features = false } # removing default, kawa will not use SSE

Did this configuration really work on your mac os aarch64?

[anonkey]

Yes it works, why shouldn't it?
If SSE4.2 available it use kawa with default features else disable default features to avoid kawa use sse4.2 optimizations

[Wonshtrum]

I agree, but it seems your configuration says the opposite. The first option (with default) is used if sse4.2 is not available (cfg(not(target_feature = "sse4.2"))), and the second (default-features=false) is used if sse4.2 is available (cfg(target_feature = "sse4.2")).
I did some tests and found that sse4.2 is never set even if the CPU supports it, unless you build with the rust flag -target-cpu=native. I must say I'm split, I firmly believe resource-intensive programs like Sozu should be built for a specific architecture to take full advantage of specific hardware features. But I also don't like making it hard to compile Sozu on a different machine than the one it will run on.

[anonkey]

Ok i understand why my test was false positive so.
So if avoiding the -target-cpu=native seem better and since the problem is import of std::arch::x86_64, is checking of the x86_64 arch ok for you ?
I checked on my arm mac and on my x86 server by inserting faulty code under the std::arch::x86_64 import it's working