Finds the index of elem in src within 0..len using SIMD intrinsics.
Assumes that len is a multiple of 16 and undefined behavior if T is not an integral or vector size.
Direction to count in, will find index if DIR == 0 or last index if DIR == 1.
Data source pointer.
Length of data to be memchrned.
Data to be searched for.
See Implementation
Finds the index of elem in src within 0..len using SIMD intrinsics.
Assumes that len is a multiple of 16 and undefined behavior if T is not an integral or vector size.