Remove unused conditional_choose function

This commit is contained in:
Henry de Valence 2017-01-06 12:29:24 -05:00
parent 098ff2ffca
commit c92ebdd0ac

View file

@ -179,49 +179,7 @@ impl FieldElement {
FieldElement([ 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 ])
}
/// Overwrite this FieldElement with one of the inputs without branching.
/// Like `conditional_assign`, but chooses between two inputs instead of
/// one input and the original value.
///
/// If `choice == 0`, replace `self` with `f`:
///
/// ```
/// # use curve25519_dalek::field::FieldElement;
/// let f = FieldElement([1,1,1,1,1,1,1,1,1,1]);
/// let g = FieldElement([2,2,2,2,2,2,2,2,2,2]);
/// let mut h = FieldElement([0,0,0,0,0,0,0,0,0,0]);
/// h.conditional_choose(&f, &g, 0);
/// assert!(h == f);
/// ```
///
/// If `choice == 1`, replace `self` with `g`:
///
/// ```
/// # use curve25519_dalek::field::FieldElement;
/// # let f = FieldElement([1,1,1,1,1,1,1,1,1,1]);
/// # let g = FieldElement([2,2,2,2,2,2,2,2,2,2]);
/// # let mut h = FieldElement([0,0,0,0,0,0,0,0,0,0]);
/// h.conditional_choose(&f, &g, 1);
/// assert!(h == g);
/// ```
///
/// # Preconditions
///
/// * `b` in {0,1}
pub fn conditional_choose(&mut self,
f: &FieldElement,
g: &FieldElement,
choice: u8)
{
let mask = -(choice as Limb);
for i in 0..10 {
self[i] = f[i] ^ (mask & (f[i] ^ g[i]));
}
}
/// Conditionally assign the Limbs of another FieldElement to this
/// one. Like `conditional_choose`, but choosing between one
/// input and the original value.
/// Conditionally assign another FieldElement to this one.
///
/// If `choice == 0`, replace `self` with `self`:
///