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/avq1oz98W - for intels Block RThroughput: =8.0; for ryzens, Block RThroughput: =4.0
So could pick cost of 8.
For store we have:
https://godbolt.org/z/89PGMc1qs - for intels Block RThroughput: =6.0; for ryzens, Block RThroughput: <=6.0
So we could pick cost of 6.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.