Unused code in mpn_mul_fft_decompose?

[Mikhail Hogrefe]

I was digging around in the GMP 6.1.2 source, and I noticed something in
mpn/generic/mul_fft.c.

In mpn_mul_fft_decompose, there is an if statement checking 'dif > Kl',
which is equivalent to 'nl > 2 * K * l'. But there is a comment above the
function saying 'We must have nl <= 2*K*l.', suggesting that the first
branch of the if is never taken.

Maybe you're already aware of this, but if not I wanted to let you know.

Best,
Mikhail Hogrefe