@RKSimon please can you check that i'm got the idea right, and not missing any steps?
The only sched models that for cpu's that support avx2 but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/M8vEKs5jY - for intels Block RThroughput: =2.0; for ryzens, Block RThroughput: <=1.0
So pick cost of 2.
For store we have:
https://godbolt.org/z/Kx1nKz7je - for intels Block RThroughput: =1.0; for ryzens, Block RThroughput: <=0.5
So pick cost of 1.
I'm directly using the shuffling asm the llc produced, without any manual fixups that may be needed to ensure sequential execution.