reduce
Reduces an arbitrary Uint, converting it to a field element.
Function parameters
Parameters
An unsigned big integer with a fixed maximum size (`max_bits`), suitable for cryptographic operations.
Functions
Error sets in this namespace
Error Sets
- OverflowError
- Value is too large for the destination.
- InvalidModulusError
- Invalid modulus.
- NullExponentError
- Exponentiation with a null exponent.
- FieldElementError
- Invalid field element for the given modulus.
- RepresentationError
- Invalid representation (Montgomery vs non-Montgomery domain.)
- Error
- The set of all possible errors `std.crypto.ff` functions can return.
Source
Implementation
pub fn reduce(self: Self, x: anytype) Fe {
var out = self.zero;
var i = x.limbs_len - 1;
if (self.limbs_count() >= 2) {
const start = @min(i, self.limbs_count() - 2);
var j = start;
while (true) : (j -= 1) {
out.v.limbs()[j] = x.limbsConst()[i];
i -= 1;
if (j == 0) break;
}
}
while (true) : (i -= 1) {
self.shiftIn(&out, x.limbsConst()[i]);
if (i == 0) break;
}
return out;
}