From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Paul Eggert <eggert@cs.ucla.edu>,
Alexander Monakov <amonakov@ispras.ru>
Subject: [PATCH v6 2/6] stdlib: Move insertion sort out qsort
Date: Tue, 18 Jul 2023 11:15:39 -0300 [thread overview]
Message-ID: <20230718141543.3925254-3-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20230718141543.3925254-1-adhemerval.zanella@linaro.org>
---
stdlib/qsort.c | 101 ++++++++++++++++++++++++++-----------------------
1 file changed, 54 insertions(+), 47 deletions(-)
diff --git a/stdlib/qsort.c b/stdlib/qsort.c
index 5bcc287c79..77630951df 100644
--- a/stdlib/qsort.c
+++ b/stdlib/qsort.c
@@ -156,6 +156,58 @@ typedef struct
smaller partition. This *guarantees* no more than log (total_elems)
stack size is needed (actually O(1) in this case)! */
+static inline void
+insertion_sort_qsort_partitions (void *const pbase, size_t total_elems,
+ size_t size, enum swap_type_t swap_func,
+ __compar_d_fn_t cmp, void *arg)
+{
+ char *base_ptr = (char *) pbase;
+ char *const end_ptr = &base_ptr[size * (total_elems - 1)];
+ char *tmp_ptr = base_ptr;
+#define min(x, y) ((x) < (y) ? (x) : (y))
+ const size_t max_thresh = MAX_THRESH * size;
+ char *thresh = min(end_ptr, base_ptr + max_thresh);
+ char *run_ptr;
+
+ /* Find smallest element in first threshold and place it at the
+ array's beginning. This is the smallest array element,
+ and the operation speeds up insertion sort's inner loop. */
+
+ for (run_ptr = tmp_ptr + size; run_ptr <= thresh; run_ptr += size)
+ if (cmp (run_ptr, tmp_ptr, arg) < 0)
+ tmp_ptr = run_ptr;
+
+ if (tmp_ptr != base_ptr)
+ do_swap (tmp_ptr, base_ptr, size, swap_func);
+
+ /* Insertion sort, running from left-hand-side up to right-hand-side. */
+
+ run_ptr = base_ptr + size;
+ while ((run_ptr += size) <= end_ptr)
+ {
+ tmp_ptr = run_ptr - size;
+ while (cmp (run_ptr, tmp_ptr, arg) < 0)
+ tmp_ptr -= size;
+
+ tmp_ptr += size;
+ if (tmp_ptr != run_ptr)
+ {
+ char *trav;
+
+ trav = run_ptr + size;
+ while (--trav >= run_ptr)
+ {
+ char c = *trav;
+ char *hi, *lo;
+
+ for (hi = lo = trav; (lo -= size) >= tmp_ptr; hi = lo)
+ *hi = *lo;
+ *hi = c;
+ }
+ }
+ }
+}
+
void
_quicksort (void *const pbase, size_t total_elems, size_t size,
__compar_d_fn_t cmp, void *arg)
@@ -278,51 +330,6 @@ _quicksort (void *const pbase, size_t total_elems, size_t size,
for partitions below MAX_THRESH size. BASE_PTR points to the beginning
of the array to sort, and END_PTR points at the very last element in
the array (*not* one beyond it!). */
-
-#define min(x, y) ((x) < (y) ? (x) : (y))
-
- {
- char *const end_ptr = &base_ptr[size * (total_elems - 1)];
- char *tmp_ptr = base_ptr;
- char *thresh = min(end_ptr, base_ptr + max_thresh);
- char *run_ptr;
-
- /* Find smallest element in first threshold and place it at the
- array's beginning. This is the smallest array element,
- and the operation speeds up insertion sort's inner loop. */
-
- for (run_ptr = tmp_ptr + size; run_ptr <= thresh; run_ptr += size)
- if ((*cmp) ((void *) run_ptr, (void *) tmp_ptr, arg) < 0)
- tmp_ptr = run_ptr;
-
- if (tmp_ptr != base_ptr)
- do_swap (tmp_ptr, base_ptr, size, swap_type);
-
- /* Insertion sort, running from left-hand-side up to right-hand-side. */
-
- run_ptr = base_ptr + size;
- while ((run_ptr += size) <= end_ptr)
- {
- tmp_ptr = run_ptr - size;
- while ((*cmp) ((void *) run_ptr, (void *) tmp_ptr, arg) < 0)
- tmp_ptr -= size;
-
- tmp_ptr += size;
- if (tmp_ptr != run_ptr)
- {
- char *trav;
-
- trav = run_ptr + size;
- while (--trav >= run_ptr)
- {
- char c = *trav;
- char *hi, *lo;
-
- for (hi = lo = trav; (lo -= size) >= tmp_ptr; hi = lo)
- *hi = *lo;
- *hi = c;
- }
- }
- }
- }
+ insertion_sort_qsort_partitions (pbase, total_elems, size, swap_type, cmp,
+ arg);
}
--
2.34.1
next prev parent reply other threads:[~2023-07-18 14:15 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-18 14:15 [PATCH v6 0/6] Use introsort for qsort Adhemerval Zanella
2023-07-18 14:15 ` [PATCH v6 1/6] stdlib: Optimization qsort{_r} swap implementation Adhemerval Zanella
2023-08-22 19:31 ` Adhemerval Zanella Netto
2023-08-29 7:33 ` Noah Goldstein
2023-08-29 13:56 ` Adhemerval Zanella Netto
2023-08-29 16:53 ` Florian Weimer
2023-08-29 22:52 ` Noah Goldstein
2023-08-30 13:51 ` Adhemerval Zanella Netto
2023-07-18 14:15 ` Adhemerval Zanella [this message]
2023-08-29 7:39 ` [PATCH v6 2/6] stdlib: Move insertion sort out qsort Noah Goldstein
2023-08-29 13:59 ` Adhemerval Zanella Netto
2023-07-18 14:15 ` [PATCH v6 3/6] stdlib: qsort: Move some macros to inline function Adhemerval Zanella
2023-07-18 14:15 ` [PATCH v6 4/6] stdlib: Implement introsort for qsort (BZ 19305) Adhemerval Zanella
2023-07-18 17:37 ` Noah Goldstein
2023-07-18 19:08 ` Adhemerval Zanella Netto
2023-08-29 7:45 ` Noah Goldstein
2023-08-31 12:13 ` Adhemerval Zanella Netto
2023-08-31 17:38 ` Noah Goldstein
2023-07-18 14:15 ` [PATCH v6 5/6] stdlib: Remove use of mergesort on qsort (BZ 21719) Adhemerval Zanella
2023-07-18 14:15 ` [PATCH v6 6/6] stdlib: Add more qsort{_r} coverage Adhemerval Zanella
2023-08-29 7:57 ` Noah Goldstein
2023-08-30 17:03 ` Adhemerval Zanella Netto
2023-08-30 18:49 ` Noah Goldstein
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