I was interested in the last point about AVX instructions, and found https://john-h-k.github.io/VexTransitionPenalties.html https://john-h-k.github.io/VexTransi

I was interested in the last point about AVX instructions, and found https://john-h-k.github.io/VexTransitionPenalties.html https://john-h-k.github.io/VexTransitionPenalties.html which discusses the problem.