On Tue, Jan 28, 2025 at 05:38:57PM +0100, Andreas Gruenbacher wrote:
In this second step, transform the eytzinger indexes i, j, and k in eytzinger1_sort_r() from 0-based to 1-based. This step looks a bit messy, but the resulting code is slightly better.
I really hate the cute and paste of lib/sort.c, I wonder if we could get rid of that by adding a more generic sort that takes an option "index/access element" helper.
I've come across situations where we want to sort radix trees as well, so - maybe?
Signed-off-by: Andreas Gruenbacher agruenba@redhat.com
fs/bcachefs/eytzinger.c | 42 ++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-)
diff --git a/fs/bcachefs/eytzinger.c b/fs/bcachefs/eytzinger.c index 93a5819a6878..00cc5f0826e3 100644 --- a/fs/bcachefs/eytzinger.c +++ b/fs/bcachefs/eytzinger.c @@ -170,7 +170,7 @@ static void eytzinger1_sort_r(void *base1, size_t n, size_t size, swap_r_func_t swap_func, const void *priv) {
- int i, j, k;
- unsigned i, j, k;
/* called from 'sort' without swap function, let's pick the default */ if (swap_func == SWAP_WRAPPER && !((struct wrapper *)priv)->swap_func) @@ -186,46 +186,46 @@ static void eytzinger1_sort_r(void *base1, size_t n, size_t size, } /* heapify */
- for (i = n / 2 - 1; i >= 0; --i) {
- for (i = n / 2; i >= 1; --i) { /* Find the sift-down path all the way to the leaves. */
for (j = i; k = j * 2 + 1, k + 1 < n;)j = eytzinger1_do_cmp(base1, n, size, cmp_func, priv, k + 1, k + 2) > 0 ? k : k + 1;
for (j = i; k = j * 2, k < n;)j = eytzinger1_do_cmp(base1, n, size, cmp_func, priv, k, k + 1) > 0 ? k : k + 1;/* Special case for the last leaf with no sibling. */
if (j * 2 + 2 == n)j = j * 2 + 1;
if (j * 2 == n)j *= 2;/* Backtrack to the correct location. */
while (j != i && eytzinger1_do_cmp(base1, n, size, cmp_func, priv, i + 1, j + 1) >= 0)j = (j - 1) / 2;
while (j != i && eytzinger1_do_cmp(base1, n, size, cmp_func, priv, i, j) >= 0)j /= 2;/* Shift the element into its correct place. */ for (k = j; j != i;) {
j = (j - 1) / 2;eytzinger1_do_swap(base1, n, size, swap_func, priv, j + 1, k + 1);
j /= 2;eytzinger1_do_swap(base1, n, size, swap_func, priv, j, k);/* sort */
- for (i = n - 1; i > 0; --i) {
eytzinger1_do_swap(base1, n, size, swap_func, priv, 1, i + 1);
- for (i = n; i > 1; --i) {
eytzinger1_do_swap(base1, n, size, swap_func, priv, 1, i);/* Find the sift-down path all the way to the leaves. */
for (j = 0; k = j * 2 + 1, k + 1 < i;)j = eytzinger1_do_cmp(base1, n, size, cmp_func, priv, k + 1, k + 2) > 0 ? k : k + 1;
for (j = 1; k = j * 2, k + 1 < i;)j = eytzinger1_do_cmp(base1, n, size, cmp_func, priv, k, k + 1) > 0 ? k : k + 1;/* Special case for the last leaf with no sibling. */
if (j * 2 + 2 == i)j = j * 2 + 1;
if (j * 2 + 1 == i)j *= 2;/* Backtrack to the correct location. */
while (j && eytzinger1_do_cmp(base1, n, size, cmp_func, priv, 1, j + 1) >= 0)j = (j - 1) / 2;
while (j >= 1 && eytzinger1_do_cmp(base1, n, size, cmp_func, priv, 1, j) >= 0)j /= 2;/* Shift the element into its correct place. */
for (k = j; j;) {j = (j - 1) / 2;eytzinger1_do_swap(base1, n, size, swap_func, priv, j + 1, k + 1);
for (k = j; j > 1;) {j /= 2;eytzinger1_do_swap(base1, n, size, swap_func, priv, j, k);}
2.48.1