| Message ID | 87o7fvttrs.fsf@oldenburg.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | stdlib: Avoid another self-comparison in qsort | expand |
On 15/11/23 03:28, Florian Weimer wrote: > In the insertion phase, we could run off the start of the array if the > comparison function never runs zero. In that case, it never finds the > initial element that terminates the iteration. > > Tested on i686-linux-gnu and x86_64-linux-gnu. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > > --- > stdlib/qsort.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/stdlib/qsort.c b/stdlib/qsort.c > index ad110e8a89..1ea31ff424 100644 > --- a/stdlib/qsort.c > +++ b/stdlib/qsort.c > @@ -217,7 +217,7 @@ insertion_sort_qsort_partitions (void *const pbase, size_t total_elems, > while ((run_ptr += size) <= end_ptr) > { > tmp_ptr = run_ptr - size; > - while (cmp (run_ptr, tmp_ptr, arg) < 0) > + while (tmp_ptr != base_ptr && cmp (run_ptr, tmp_ptr, arg) < 0) > tmp_ptr -= size; > > tmp_ptr += size; > > base-commit: 323f367cc46b80224d39b082adf7be74b49ed843 >
* Adhemerval Zanella Netto: >> --- >> stdlib/qsort.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/stdlib/qsort.c b/stdlib/qsort.c >> index ad110e8a89..1ea31ff424 100644 >> --- a/stdlib/qsort.c >> +++ b/stdlib/qsort.c >> @@ -217,7 +217,7 @@ insertion_sort_qsort_partitions (void *const pbase, size_t total_elems, >> while ((run_ptr += size) <= end_ptr) >> { >> tmp_ptr = run_ptr - size; >> - while (cmp (run_ptr, tmp_ptr, arg) < 0) >> + while (tmp_ptr != base_ptr && cmp (run_ptr, tmp_ptr, arg) < 0) >> tmp_ptr -= size; >> >> tmp_ptr += size; Hmm, shouldn't the new condition be run_ptr != tmp_ptr, so that we avoid a pointless cmp call in more cases? Thanks, Florian
diff --git a/stdlib/qsort.c b/stdlib/qsort.c index ad110e8a89..1ea31ff424 100644 --- a/stdlib/qsort.c +++ b/stdlib/qsort.c @@ -217,7 +217,7 @@ insertion_sort_qsort_partitions (void *const pbase, size_t total_elems, while ((run_ptr += size) <= end_ptr) { tmp_ptr = run_ptr - size; - while (cmp (run_ptr, tmp_ptr, arg) < 0) + while (tmp_ptr != base_ptr && cmp (run_ptr, tmp_ptr, arg) < 0) tmp_ptr -= size; tmp_ptr += size;