🔬This is a nightly-only experimental API. (
Available on (x86 or x86-64) and target feature
avx512bitalgand x86 only.
Considers the input
b as packed 64-bit integers and
c as packed 8-bit integers.
Then groups 8 8-bit values from
cas indices into the bits of the corresponding 64-bit integer.
It then selects these bits and packs them into the output.