From: Connor Abbott Date: Mon, 20 May 2019 13:14:04 +0000 (+0200) Subject: util/set: Use fast modulo computation X-Git-Url: https://git.libre-soc.org/?p=mesa.git;a=commitdiff_plain;h=83667f7a61c9b540d1f649db67a4bcfdda096a6c util/set: Use fast modulo computation Compilation times with my shader-db database: Difference at 95.0% confidence -1.22312 +/- 0.726033 -0.283979% +/- 0.168254% (Student's t, pooled s = 1.02177) Reviewed-by: Eric Anholt Acked-by: Jason Ekstrand --- diff --git a/src/util/set.c b/src/util/set.c index 7311f4336e8..4788b94324a 100644 --- a/src/util/set.c +++ b/src/util/set.c @@ -40,6 +40,7 @@ #include "macros.h" #include "ralloc.h" #include "set.h" +#include "fast_urem_by_const.h" /* * From Knuth -- a good choice for hash/rehash values is p, p-2 where @@ -52,38 +53,43 @@ static const void *deleted_key = &deleted_key_value; static const struct { uint32_t max_entries, size, rehash; + uint64_t size_magic, rehash_magic; } hash_sizes[] = { - { 2, 5, 3 }, - { 4, 7, 5 }, - { 8, 13, 11 }, - { 16, 19, 17 }, - { 32, 43, 41 }, - { 64, 73, 71 }, - { 128, 151, 149 }, - { 256, 283, 281 }, - { 512, 571, 569 }, - { 1024, 1153, 1151 }, - { 2048, 2269, 2267 }, - { 4096, 4519, 4517 }, - { 8192, 9013, 9011 }, - { 16384, 18043, 18041 }, - { 32768, 36109, 36107 }, - { 65536, 72091, 72089 }, - { 131072, 144409, 144407 }, - { 262144, 288361, 288359 }, - { 524288, 576883, 576881 }, - { 1048576, 1153459, 1153457 }, - { 2097152, 2307163, 2307161 }, - { 4194304, 4613893, 4613891 }, - { 8388608, 9227641, 9227639 }, - { 16777216, 18455029, 18455027 }, - { 33554432, 36911011, 36911009 }, - { 67108864, 73819861, 73819859 }, - { 134217728, 147639589, 147639587 }, - { 268435456, 295279081, 295279079 }, - { 536870912, 590559793, 590559791 }, - { 1073741824, 1181116273, 1181116271 }, - { 2147483648ul, 2362232233ul, 2362232231ul } +#define ENTRY(max_entries, size, rehash) \ + { max_entries, size, rehash, \ + REMAINDER_MAGIC(size), REMAINDER_MAGIC(rehash) } + + ENTRY(2, 5, 3 ), + ENTRY(4, 7, 5 ), + ENTRY(8, 13, 11 ), + ENTRY(16, 19, 17 ), + ENTRY(32, 43, 41 ), + ENTRY(64, 73, 71 ), + ENTRY(128, 151, 149 ), + ENTRY(256, 283, 281 ), + ENTRY(512, 571, 569 ), + ENTRY(1024, 1153, 1151 ), + ENTRY(2048, 2269, 2267 ), + ENTRY(4096, 4519, 4517 ), + ENTRY(8192, 9013, 9011 ), + ENTRY(16384, 18043, 18041 ), + ENTRY(32768, 36109, 36107 ), + ENTRY(65536, 72091, 72089 ), + ENTRY(131072, 144409, 144407 ), + ENTRY(262144, 288361, 288359 ), + ENTRY(524288, 576883, 576881 ), + ENTRY(1048576, 1153459, 1153457 ), + ENTRY(2097152, 2307163, 2307161 ), + ENTRY(4194304, 4613893, 4613891 ), + ENTRY(8388608, 9227641, 9227639 ), + ENTRY(16777216, 18455029, 18455027 ), + ENTRY(33554432, 36911011, 36911009 ), + ENTRY(67108864, 73819861, 73819859 ), + ENTRY(134217728, 147639589, 147639587 ), + ENTRY(268435456, 295279081, 295279079 ), + ENTRY(536870912, 590559793, 590559791 ), + ENTRY(1073741824, 1181116273, 1181116271 ), + ENTRY(2147483648ul, 2362232233ul, 2362232231ul ) }; static int @@ -119,6 +125,8 @@ _mesa_set_create(void *mem_ctx, ht->size_index = 0; ht->size = hash_sizes[ht->size_index].size; ht->rehash = hash_sizes[ht->size_index].rehash; + ht->size_magic = hash_sizes[ht->size_index].size_magic; + ht->rehash_magic = hash_sizes[ht->size_index].rehash_magic; ht->max_entries = hash_sizes[ht->size_index].max_entries; ht->key_hash_function = key_hash_function; ht->key_equals_function = key_equals_function; @@ -207,8 +215,9 @@ static struct set_entry * set_search(const struct set *ht, uint32_t hash, const void *key) { uint32_t size = ht->size; - uint32_t start_address = hash % size; - uint32_t double_hash = hash % ht->rehash + 1; + uint32_t start_address = util_fast_urem32(hash, size, ht->size_magic); + uint32_t double_hash = util_fast_urem32(hash, ht->rehash, + ht->rehash_magic) + 1; uint32_t hash_address = start_address; do { struct set_entry *entry = ht->table + hash_address; @@ -249,8 +258,9 @@ static void set_add_rehash(struct set *ht, uint32_t hash, const void *key) { uint32_t size = ht->size; - uint32_t start_address = hash % size; - uint32_t double_hash = hash % ht->rehash + 1; + uint32_t start_address = util_fast_urem32(hash, size, ht->size_magic); + uint32_t double_hash = util_fast_urem32(hash, ht->rehash, + ht->rehash_magic) + 1; uint32_t hash_address = start_address; do { struct set_entry *entry = ht->table + hash_address; @@ -286,6 +296,8 @@ set_rehash(struct set *ht, unsigned new_size_index) ht->size_index = new_size_index; ht->size = hash_sizes[ht->size_index].size; ht->rehash = hash_sizes[ht->size_index].rehash; + ht->size_magic = hash_sizes[ht->size_index].size_magic; + ht->rehash_magic = hash_sizes[ht->size_index].rehash_magic; ht->max_entries = hash_sizes[ht->size_index].max_entries; ht->entries = 0; ht->deleted_entries = 0; @@ -332,8 +344,9 @@ set_search_or_add(struct set *ht, uint32_t hash, const void *key, bool *found) } uint32_t size = ht->size; - uint32_t start_address = hash % size; - uint32_t double_hash = hash % ht->rehash + 1; + uint32_t start_address = util_fast_urem32(hash, size, ht->size_magic); + uint32_t double_hash = util_fast_urem32(hash, ht->rehash, + ht->rehash_magic) + 1; uint32_t hash_address = start_address; do { struct set_entry *entry = ht->table + hash_address; diff --git a/src/util/set.h b/src/util/set.h index 783c3d41c46..55857aca7ab 100644 --- a/src/util/set.h +++ b/src/util/set.h @@ -47,6 +47,8 @@ struct set { bool (*key_equals_function)(const void *a, const void *b); uint32_t size; uint32_t rehash; + uint64_t size_magic; + uint64_t rehash_magic; uint32_t max_entries; uint32_t size_index; uint32_t entries;