I think the article is pretty meticulous about differentiating between compiler issues (the compiler not recognizing an opportunity to use overflow bits, for ex

I think the article is pretty meticulous about differentiating between compiler issues (the compiler not recognizing an opportunity to use overflow bits, for example) and C problems (multiplication producing an output the same size as the inputs, which is broken for a large proportion of inputs -- which the writer calls out as an over-generalization).