public static long multiplicationComplexity(final long x) {
    if (x <= 64) {
      return square(x);
    } else if (x <= 1024) {
      return clampedAdd((square(x) / 4), clampedMultiply(x, 96)) - 3072;
    } else {
      return clampedAdd((square(x) / 16), clampedMultiply(480, x)) - 199680;
    }
  }
Equation to estimate the multiplication complexity.

@param x the x
@return the long
evm/src/main/java/org/hyperledger/besu/evm/precompile/BigIntegerModularExponentiationPrecompiledContract.java