On Sat, 15 Jul 2017, Segher Boessenkool wrote:
> Would it hurt us to use stable sorts *everywhere*?
Stability (using the usual definition: keeping the original order of
elements that compare equal) is not required to achieve reproducibility [*].
GCC could import or nih any non-randomized implementation of a [potentially
not stable, e.g. qsort] sorting routine, and that would be sufficient
to eliminate this source of codegen differences.
Alexander
[*] nor would it be sufficient, given our current practice of passing
invalid comparators to libc sort, at which point anything can happen
due to undefined behavior
