Yes. Flipping the sign of a number can typically be done in one line as `d = -d`. Or if that syntax isn't available in that programming language, then `d = 0 - d` or `d = -1 * d`.

What's wrong with code above is 1) it does a conditional branch (meaning if.. then... else...) which is unneeded. 2) The "then clause" does an absolute value which is a waste of a function call. 3) The "else clause" does `d = d - (2 * d)` which is a waste of a multiplication 4) possibly with an overflow risk and/or floating point estimation risk.

That said, it's admittedly possible that the programming language above, or the number representation in that code above, have some highly atypical needs that we here on HN don't understand.