On Sun, 16 Jul 2017, Segher Boessenkool wrote: > I am well aware, and that is not what I asked. If we would use stable > sorts everywhere
How? There's no stable sort in libc and switching over to std::stable_sort would be problematic. The obvious approach is adding an implementation of a stable sort in GCC, but at that point it doesn't matter if it's stable, the fact it's deterministic is sufficient for reproducibility. > we would not have to think about whether some sorting routine has to be > stable or if we can get away with a (slightly slower) non-stable sort. I think you mean '(slightly faster)'. > That is just a plain bug, undefined behaviour even (C11 7.22.5/4). > Of course it needs to be fixed. I've posted patches towards this goal. Alexander
