> Before running the code, make sure your CPU does support AVX2. ... You should see "sse2" at a minimum. AVX2 is not SSE2 - SSE2 is much, much older. You want

> Before running the code, make sure your CPU does support AVX2. ... You should see "sse2" at a minimum. AVX2 is not SSE2 - SSE2 is much, much older. You want to check for the avx2 flag itself.