Mesa: short-circuit case when looking up the same program twice in cache
diff --git a/src/mesa/shader/prog_cache.c b/src/mesa/shader/prog_cache.c
index 36a2537..9437e59 100644
--- a/src/mesa/shader/prog_cache.c
+++ b/src/mesa/shader/prog_cache.c
@@ -44,6 +44,7 @@
struct gl_program_cache
{
struct cache_item **items;
+ struct cache_item *last;
GLuint size, n_items;
};
@@ -83,6 +84,8 @@
struct cache_item *c, *next;
GLuint size, i;
+ cache->last = NULL;
+
size = cache->size * 3;
items = (struct cache_item**) _mesa_malloc(size * sizeof(*items));
_mesa_memset(items, 0, size * sizeof(*items));
@@ -105,6 +108,8 @@
{
struct cache_item *c, *next;
GLuint i;
+
+ cache->last = NULL;
for (i = 0; i < cache->size; i++) {
for (c = cache->items[i]; c; c = next) {
@@ -149,18 +154,26 @@
struct gl_program *
-_mesa_search_program_cache(const struct gl_program_cache *cache,
+_mesa_search_program_cache(struct gl_program_cache *cache,
const void *key, GLuint keysize)
{
- const GLuint hash = hash_key(key, keysize);
- struct cache_item *c;
-
- for (c = cache->items[hash % cache->size]; c; c = c->next) {
- if (c->hash == hash && memcmp(c->key, key, keysize) == 0)
- return c->program;
+ if (cache->last &&
+ memcmp(cache->last->key, key, keysize) == 0) {
+ return cache->last->program;
}
+ else {
+ const GLuint hash = hash_key(key, keysize);
+ struct cache_item *c;
- return NULL;
+ for (c = cache->items[hash % cache->size]; c; c = c->next) {
+ if (c->hash == hash && memcmp(c->key, key, keysize) == 0) {
+ cache->last = c;
+ return c->program;
+ }
+ }
+
+ return NULL;
+ }
}