Function add [src]

r = a + b r, a and b may be aliases. Asserts the result fits in r. An upper bound on the number of limbs needed by r is @max(a.limbs.len, b.limbs.len) + 1.

Prototype

pub fn add(r: *Mutable, a: Const, b: Const) void

Parameters

r: *Mutablea: Constb: Const

Source

  pub fn add(r: *Mutable, a: Const, b: Const) void {
    if (r.addCarry(a, b)) {
        // Fix up the result. Note that addCarry normalizes by a.limbs.len or b.limbs.len,
        // so we need to set the length here.
        const msl = @max(a.limbs.len, b.limbs.len);
        // `[add|sub]Carry` normalizes by `msl`, so we need to fix up the result manually here.
        // Note, the fact that it normalized means that the intermediary limbs are zero here.
        r.len = msl + 1;
        r.limbs[msl] = 1; // If this panics, there wasn't enough space in `r`.
    }
}  