diff options
Diffstat (limited to 'lib/sort.c')
| -rw-r--r-- | lib/sort.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/sort.c b/lib/sort.c index 048b7a6ef967..8e73dc55476b 100644 --- a/lib/sort.c +++ b/lib/sort.c @@ -200,6 +200,13 @@ static size_t parent(size_t i, unsigned int lsbit, size_t size) * copy (e.g. fix up pointers or auxiliary data), but the built-in swap * avoids a slow retpoline and so is significantly faster. * + * The comparison function must adhere to specific mathematical + * properties to ensure correct and stable sorting: + * - Antisymmetry: cmp_func(a, b) must return the opposite sign of + * cmp_func(b, a). + * - Transitivity: if cmp_func(a, b) <= 0 and cmp_func(b, c) <= 0, then + * cmp_func(a, c) <= 0. + * * Sorting time is O(n log n) both on average and worst-case. While * quicksort is slightly faster on average, it suffers from exploitable * O(n*n) worst-case behavior and extra memory requirements that make |