pub unsafe fn _bextr2_u64(a: u64, control: u64) -> u64
Available on non-crate feature miri-test-libstd and x86-64 and non-x86 only.
Expand description

Extracts bits of a specified by control into the least significant bits of the result.

Bits [7,0] of control specify the index to the first bit in the range to be extracted, and bits [15,8] specify the length of the range.

Intel’s documentation