gallium/cso_hash: remove another layer of pointer indirection

Convert this:

    struct cso_hash {
       union {
          struct cso_hash_data *d;
          struct cso_node      *e;
       } data;
    };

to this:

    struct cso_hash {
       struct cso_hash_data data;
       struct cso_node      *end;
    };

1) data is not a pointer anymore.
2) "end" points to "data" and acts as the end of the linked list.
3) This code is still crazy.

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3829>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3829>

src/gallium/auxiliary/cso_cache/cso_hash.c

@@ -88,7 +88,7 @@ cso_hash_create_node(struct cso_hash *hash,
 
    node->next = *anextNode;
    *anextNode = node;
-   ++hash->data.d->size;
+   ++hash->data.size;
    return node;
 }
 
@@ -173,7 +173,7 @@ static struct cso_node *cso_data_first_node(struct cso_hash_data *hash)
 struct cso_hash_iter cso_hash_insert(struct cso_hash *hash,
                                      unsigned key, void *data)
 {
-   cso_data_might_grow(hash->data.d);
+   cso_data_might_grow(&hash->data);
 
    struct cso_node **nextNode = cso_hash_find_node(hash, key);
    struct cso_node *node = cso_hash_create_node(hash, key, data, nextNode);
@@ -186,26 +186,22 @@ struct cso_hash_iter cso_hash_insert(struct cso_hash *hash,
    return iter;
 }
 
-bool cso_hash_init(struct cso_hash *hash)
+void cso_hash_init(struct cso_hash *hash)
 {
-   hash->data.d = MALLOC_STRUCT(cso_hash_data);
-   if (!hash->data.d)
-      return false;
-
-   hash->data.d->fakeNext = 0;
-   hash->data.d->buckets = 0;
-   hash->data.d->size = 0;
-   hash->data.d->userNumBits = (short)MinNumBits;
-   hash->data.d->numBits = 0;
-   hash->data.d->numBuckets = 0;
-   return true;
+   hash->data.fakeNext = 0;
+   hash->data.buckets = 0;
+   hash->data.size = 0;
+   hash->data.userNumBits = (short)MinNumBits;
+   hash->data.numBits = 0;
+   hash->data.numBuckets = 0;
+   hash->end = (struct cso_node*)&hash->data;
 }
 
 void cso_hash_deinit(struct cso_hash *hash)
 {
-   struct cso_node *e_for_x = (struct cso_node *)hash->data.d;
-   struct cso_node **bucket = hash->data.d->buckets;
-   int n = hash->data.d->numBuckets;
+   struct cso_node *e_for_x = hash->end;
+   struct cso_node **bucket = hash->data.buckets;
+   int n = hash->data.numBuckets;
 
    while (n--) {
       struct cso_node *cur = *bucket++;
@@ -215,14 +211,12 @@ void cso_hash_deinit(struct cso_hash *hash)
          cur = next;
       }
    }
-   FREE(hash->data.d->buckets);
-   FREE(hash->data.d);
-   hash->data.d = NULL;
+   FREE(hash->data.buckets);
 }
 
 unsigned cso_hash_iter_key(struct cso_hash_iter iter)
 {
-   if (!iter.node || iter.hash->data.e == iter.node)
+   if (!iter.node || iter.hash->end == iter.node)
       return 0;
    return iter.node->key;
 }
@@ -299,13 +293,13 @@ void *cso_hash_take(struct cso_hash *hash, unsigned akey)
 {
    struct cso_node **node = cso_hash_find_node(hash, akey);
 
-   if (*node != hash->data.e) {
+   if (*node != hash->end) {
       void *t = (*node)->value;
       struct cso_node *next = (*node)->next;
       FREE(*node);
       *node = next;
-      --hash->data.d->size;
-      cso_data_has_shrunk(hash->data.d);
+      --hash->data.size;
+      cso_data_has_shrunk(&hash->data);
       return t;
    }
    return NULL;
@@ -320,13 +314,13 @@ struct cso_hash_iter cso_hash_iter_prev(struct cso_hash_iter iter)
 
 struct cso_hash_iter cso_hash_first_node(struct cso_hash *hash)
 {
-   struct cso_hash_iter iter = {hash, cso_data_first_node(hash->data.d)};
+   struct cso_hash_iter iter = {hash, cso_data_first_node(&hash->data)};
    return iter;
 }
 
 int cso_hash_size(struct cso_hash *hash)
 {
-   return hash->data.d->size;
+   return hash->data.size;
 }
 
 struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter iter)
@@ -335,21 +329,21 @@ struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter
    struct cso_node *node = iter.node;
    struct cso_node **node_ptr;
 
-   if (node == hash->data.e)
+   if (node == hash->end)
       return iter;
 
    ret = cso_hash_iter_next(ret);
-   node_ptr = &hash->data.d->buckets[node->key % hash->data.d->numBuckets];
+   node_ptr = &hash->data.buckets[node->key % hash->data.numBuckets];
    while (*node_ptr != node)
       node_ptr = &(*node_ptr)->next;
    *node_ptr = node->next;
    FREE(node);
-   --hash->data.d->size;
+   --hash->data.size;
    return ret;
 }
 
 bool cso_hash_contains(struct cso_hash *hash, unsigned key)
 {
    struct cso_node **node = cso_hash_find_node(hash, key);
-   return *node != hash->data.e;
+   return *node != hash->end;
 }

src/gallium/auxiliary/cso_cache/cso_hash.h

@@ -57,13 +57,6 @@ struct cso_node {
    void *value;
 };
 
-struct cso_hash {
-   union {
-      struct cso_hash_data *d;
-      struct cso_node      *e;
-   } data;
-};
-
 struct cso_hash_iter {
    struct cso_hash *hash;
    struct cso_node  *node;
@@ -78,7 +71,12 @@ struct cso_hash_data {
    int numBuckets;
 };
 
-bool cso_hash_init(struct cso_hash *hash);
+struct cso_hash {
+   struct cso_hash_data data;
+   struct cso_node      *end;
+};
+
+void cso_hash_init(struct cso_hash *hash);
 void cso_hash_deinit(struct cso_hash *hash);
 
 
@@ -135,13 +133,13 @@ struct cso_node *cso_hash_data_next(struct cso_node *node);
 static inline bool
 cso_hash_iter_is_null(struct cso_hash_iter iter)
 {
-   return !iter.node || iter.node == iter.hash->data.e;
+   return !iter.node || iter.node == iter.hash->end;
 }
 
 static inline void *
 cso_hash_iter_data(struct cso_hash_iter iter)
 {
-   if (!iter.node || iter.hash->data.e == iter.node)
+   if (!iter.node || iter.hash->end == iter.node)
       return NULL;
    return iter.node->value;
 }
@@ -151,13 +149,13 @@ cso_hash_find_node(struct cso_hash *hash, unsigned akey)
 {
    struct cso_node **node;
 
-   if (hash->data.d->numBuckets) {
-      node = &hash->data.d->buckets[akey % hash->data.d->numBuckets];
-      assert(*node == hash->data.e || (*node)->next);
-      while (*node != hash->data.e && (*node)->key != akey)
+   if (hash->data.numBuckets) {
+      node = &hash->data.buckets[akey % hash->data.numBuckets];
+      assert(*node == hash->end || (*node)->next);
+      while (*node != hash->end && (*node)->key != akey)
          node = &(*node)->next;
    } else {
-      node = &hash->data.e;
+      node = &hash->end;
    }
    return node;
 }

src/gallium/auxiliary/util/u_hash_table.c

@@ -85,10 +85,7 @@ util_hash_table_create(unsigned (*hash)(void *key),
    if (!ht)
       return NULL;
    
-   if (!cso_hash_init(&ht->cso)) {
-      FREE(ht);
-      return NULL;
-   }
+   cso_hash_init(&ht->cso);
    
    ht->hash = hash;
    ht->compare = compare;

src/gallium/auxiliary/util/u_surfaces.c

@@ -39,7 +39,7 @@ util_surfaces_do_get(struct util_surfaces *us, unsigned surface_struct_size,
 
    if(pt->target == PIPE_TEXTURE_3D || pt->target == PIPE_TEXTURE_CUBE)
    {    /* or 2D array */
-      if (!us->u.hash.data.d)
+      if (!us->u.hash.end)
          cso_hash_init(&us->u.hash);
 
       ps = cso_hash_iter_data(cso_hash_find(&us->u.hash, (layer << 8) | level));