full-adder implementation

full_adder.py

# Full adder implementation
# Paulus Gandung Prakosa <[email protected]>
# ref: https://en.wikipedia.org/wiki/Adder_(electronics)#Full_adder

import math
import sys

def bit_count(x):
	return x if x == 0 else math.floor(math.log2(x)) + 1

def extract_bit(x, pos):
	if pos == 0:
		return False

	return (x & (1 << (pos - 1))) >> (pos - 1)

def _xor(a, b):
	return a ^ b

def _and(a, b):
	return a & b

def _or(a, b):
	return a | b

def add(x, y):
	a = bit_count(x)
	b = bit_count(y)
	p = (a if a > b else b)
	r = c = 0

	for i in range(1, p + 1):
		o = extract_bit(x, i)
		l = extract_bit(y, i)
		t = _xor(_xor(c, o), l)
		c = _or(_and(o, l), _and(c, _xor(o, l)))
		r = _or(r, (1 << (i - 1)) if t == 1 else 0)

	if c == 1:
		r = _or(r, 1 << p)

	return r

if __name__ == '__main__':
	print(add(int(sys.argv[1]), int(sys.argv[2])))

This is really amazing :)

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muantapp mass \ :v /

cool ✨