It it by definition not a tautology because it's not a truth statement. It couldn't be a tautology if it wanted to. It's an equation. You are free to enter any values into and you'll get the output. How useful or valuable the equation is to predicting reality is an entirely different matter.
'Cause you know that I have no fear, ain't gonna walk into the river and disappear. I'm gonna be a powerful man. Red blood running down the broken sand.