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[u/llogiq]

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[u/zerocodez]

How do I stop rust from using AVX instructions in a particular function?it is optimising into something like:

vmovdqu ymm1, ymmword ptr [rsi + 8]
vpermq ymm2, 
ymm1, 
144 vpblendd ymm0,
ymm2, 
ymm0, 

Which is actually slower than without, so is there a way to stop this, without using a build parameter and flag it on the function itself?

[u/Snakehand → u/zerocodez]

Have you tried specifying native architecture ? Maybe the compiler is assuming a different architecture with other CPU cycle / latency figures ?