Function risc0_zkp::core::ntt::bit_reverse

pub fn bit_reverse<T: Copy>(io: &mut [T])

Bit-reverses the indices in an array of (1 << n) numbers. This permutes the values in the array so that a value which is previously in index i will now go in the index i’, given by reversing the bits of i.

Example

For example, with the array given below of size n=4, the indices are 0, 1, 2, 3; bitwise, they’re 0, 01, 10, 11.

Reversed, these give 0, 10, 01, 11, permuting the second and third values.

let mut some_values = [1, 2, 3, 4];
bit_reverse(&mut some_values);
assert_eq!(some_values, [1, 3, 2, 4]);