Re: [PATCH] H8/300: sim: Fix simulator hang caused by qsort on Windows/MinGW.

[Jeff Law <jeffrey.law@oss.qualcomm.com>]

On 8/29/26 7:40 PM, Jan Dubiec wrote:
> On 27.08.2026 17:19, Tom Tromey wrote:
>>>>>>> "Jan" == Jan Dubiec <jdx@o2.pl> writes:
>>
>> Jan> So I think the best solution is to use a sorting algorithm known 
>> to be
>> Jan> stable on every host, e.g. the insertion sort implementation 
>> from my
>> Jan> previous message.
>>
>> Would it be possible to change the comparison function to be stable?
>
> It is impossible by definition, because stability is a property of the 
> sorting algorithm, not the comparator. However, the comparator can be 
> modified in such a way that an unstable sorting algorithm produces a 
> “good enough” result.
When the comparator returns "0", the order of those two elements is 
unspecified  in the final output of qsort.  That introduces host 
dependencies in behavior that we very much want to avoid.

The traditional way to fix that is to fix the comparator to not return 0 
by introducing additional sort keys.    He may have been a bit imprecise 
by saying "change the comparison function to be stable", but the intent 
is clear and consistent with how this issue has been handled through the 
decades.

Jeff