Final results of tools/speed/
10000000 (10 runs) shows a slight
slowdown in some tests, but it makes an empty htable smaller.
-Initial delete all: 96-98(96.4+/-0.66) ns
+Initial delete all: 97-99(98.2+/-0.75) ns
-Initial re-inserting: 117-124(121.4+/-1.9) ns
+Initial re-inserting: 124-131(126.4+/-2.4) ns
-Adding (a different) half: 49-50(49.3+/-0.46) ns
+Adding (a different) half: 50-52(51.2+/-0.75) ns
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
/* We use 0x1 as deleted marker. */
#define HTABLE_DELETED (0x1)
/* We use 0x1 as deleted marker. */
#define HTABLE_DELETED (0x1)
+/* perfect_bitnum 63 means there's no perfect bitnum */
+#define NO_PERFECT_BIT (sizeof(uintptr_t) * CHAR_BIT - 1)
+
static void *htable_default_alloc(struct htable *ht, size_t len)
{
return calloc(len, 1);
static void *htable_default_alloc(struct htable *ht, size_t len)
{
return calloc(len, 1);
return e > HTABLE_DELETED;
}
return e > HTABLE_DELETED;
}
-/* We use 0 to mean we don't have a perfect bit, otherwise it's
- * bit n - 1 */
static inline uintptr_t ht_perfect_mask(const struct htable *ht)
{
static inline uintptr_t ht_perfect_mask(const struct htable *ht)
{
- if (ht->perfect_bitnum > 0)
- return (uintptr_t)1 << (ht->perfect_bitnum - 1);
- return 0;
+ return (uintptr_t)2 << ht->perfect_bitnum;
}
static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
}
static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
ht->bits++;
/* If we lost our "perfect bit", get it back now. */
ht->bits++;
/* If we lost our "perfect bit", get it back now. */
- if (ht->perfect_bitnum == 0 && ht->common_mask) {
+ if (ht->perfect_bitnum == NO_PERFECT_BIT && ht->common_mask) {
for (i = 0; i < sizeof(ht->common_mask) * CHAR_BIT; i++) {
for (i = 0; i < sizeof(ht->common_mask) * CHAR_BIT; i++) {
- if (ht->common_mask & ((size_t)1 << i)) {
- ht->perfect_bitnum = i + 1;
+ if (ht->common_mask & ((size_t)2 << i)) {
+ ht->perfect_bitnum = i;
static COLD void rehash_table(struct htable *ht)
{
size_t start, i;
static COLD void rehash_table(struct htable *ht)
{
size_t start, i;
+ uintptr_t e, perfect = ht_perfect_mask(ht);
/* Beware wrap cases: we need to start from first empty bucket. */
for (start = 0; ht->table[start]; start++);
/* Beware wrap cases: we need to start from first empty bucket. */
for (start = 0; ht->table[start]; start++);
continue;
if (e == HTABLE_DELETED)
ht->table[h] = 0;
continue;
if (e == HTABLE_DELETED)
ht->table[h] = 0;
- else if (!(e & ht_perfect_mask(ht))) {
+ else if (!(e & perfect)) {
void *p = get_raw_ptr(ht, e);
ht->table[h] = 0;
ht_add(ht, p, ht->rehash(p, ht->priv));
void *p = get_raw_ptr(ht, e);
ht->table[h] = 0;
ht_add(ht, p, ht->rehash(p, ht->priv));
ht->common_mask = ~((uintptr_t)1 << i);
ht->common_bits = ((uintptr_t)p & ht->common_mask);
ht->common_mask = ~((uintptr_t)1 << i);
ht->common_bits = ((uintptr_t)p & ht->common_mask);
- ht->perfect_bitnum = 1;
+ ht->perfect_bitnum = 0;
(void)htable_debug(ht, HTABLE_LOC);
return;
}
(void)htable_debug(ht, HTABLE_LOC);
return;
}
ht->common_mask &= ~maskdiff;
ht->common_bits &= ~maskdiff;
if (ht_perfect_mask(ht) & maskdiff)
ht->common_mask &= ~maskdiff;
ht->common_bits &= ~maskdiff;
if (ht_perfect_mask(ht) & maskdiff)
- ht->perfect_bitnum = 0;
+ ht->perfect_bitnum = NO_PERFECT_BIT;
(void)htable_debug(ht, HTABLE_LOC);
}
(void)htable_debug(ht, HTABLE_LOC);
}