X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=libiberty%2Fsplay-tree.c;h=7c8973c63c8fead8e1363f4f42a5f686fb16ac8c;hb=f1cee837665a932d3d747597d8512cd0d3650478;hp=311b49edffbcf011f88993fd7d553fdd80a19e35;hpb=979c05d32447bf9388479ed6ef8e5665b40e5763;p=binutils-gdb.git diff --git a/libiberty/splay-tree.c b/libiberty/splay-tree.c index 311b49edffb..7c8973c63c8 100644 --- a/libiberty/splay-tree.c +++ b/libiberty/splay-tree.c @@ -1,5 +1,5 @@ /* A splay-tree datatype. - Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. + Copyright (C) 1998-2021 Free Software Foundation, Inc. Contributed by Mark Mitchell (mark@markmitchell.com). This file is part of GNU CC. @@ -31,6 +31,9 @@ Boston, MA 02110-1301, USA. */ #ifdef HAVE_STDLIB_H #include #endif +#ifdef HAVE_STRING_H +#include +#endif #include @@ -38,13 +41,12 @@ Boston, MA 02110-1301, USA. */ #include "splay-tree.h" static void splay_tree_delete_helper (splay_tree, splay_tree_node); +static inline void rotate_left (splay_tree_node *, + splay_tree_node, splay_tree_node); +static inline void rotate_right (splay_tree_node *, + splay_tree_node, splay_tree_node); static void splay_tree_splay (splay_tree, splay_tree_key); -static splay_tree_node splay_tree_splay_helper (splay_tree, - splay_tree_key, - splay_tree_node*, - splay_tree_node*, - splay_tree_node*); -static int splay_tree_foreach_helper (splay_tree, splay_tree_node, +static int splay_tree_foreach_helper (splay_tree_node, splay_tree_foreach_fn, void*); /* Deallocate NODE (a member of SP), and all its sub-trees. */ @@ -107,116 +109,33 @@ splay_tree_delete_helper (splay_tree sp, splay_tree_node node) #undef VDEL } -/* Help splay SP around KEY. PARENT and GRANDPARENT are the parent - and grandparent, respectively, of NODE. */ +/* Rotate the edge joining the left child N with its parent P. PP is the + grandparents' pointer to P. */ -static splay_tree_node -splay_tree_splay_helper (splay_tree sp, splay_tree_key key, - splay_tree_node *node, splay_tree_node *parent, - splay_tree_node *grandparent) +static inline void +rotate_left (splay_tree_node *pp, splay_tree_node p, splay_tree_node n) { - splay_tree_node *next; - splay_tree_node n; - int comparison; - - n = *node; - - if (!n) - return *parent; - - comparison = (*sp->comp) (key, n->key); - - if (comparison == 0) - /* We've found the target. */ - next = 0; - else if (comparison < 0) - /* The target is to the left. */ - next = &n->left; - else - /* The target is to the right. */ - next = &n->right; - - if (next) - { - /* Continue down the tree. */ - n = splay_tree_splay_helper (sp, key, next, node, parent); - - /* The recursive call will change the place to which NODE - points. */ - if (*node != n) - return n; - } - - if (!parent) - /* NODE is the root. We are done. */ - return n; - - /* First, handle the case where there is no grandparent (i.e., - *PARENT is the root of the tree.) */ - if (!grandparent) - { - if (n == (*parent)->left) - { - *node = n->right; - n->right = *parent; - } - else - { - *node = n->left; - n->left = *parent; - } - *parent = n; - return n; - } + splay_tree_node tmp; + tmp = n->right; + n->right = p; + p->left = tmp; + *pp = n; +} - /* Next handle the cases where both N and *PARENT are left children, - or where both are right children. */ - if (n == (*parent)->left && *parent == (*grandparent)->left) - { - splay_tree_node p = *parent; - - (*grandparent)->left = p->right; - p->right = *grandparent; - p->left = n->right; - n->right = p; - *grandparent = n; - return n; - } - else if (n == (*parent)->right && *parent == (*grandparent)->right) - { - splay_tree_node p = *parent; - - (*grandparent)->right = p->left; - p->left = *grandparent; - p->right = n->left; - n->left = p; - *grandparent = n; - return n; - } +/* Rotate the edge joining the right child N with its parent P. PP is the + grandparents' pointer to P. */ - /* Finally, deal with the case where N is a left child, but *PARENT - is a right child, or vice versa. */ - if (n == (*parent)->left) - { - (*parent)->left = n->right; - n->right = *parent; - (*grandparent)->right = n->left; - n->left = *grandparent; - *grandparent = n; - return n; - } - else - { - (*parent)->right = n->left; - n->left = *parent; - (*grandparent)->left = n->right; - n->right = *grandparent; - *grandparent = n; - return n; - } +static inline void +rotate_right (splay_tree_node *pp, splay_tree_node p, splay_tree_node n) +{ + splay_tree_node tmp; + tmp = n->left; + n->left = p; + p->right = tmp; + *pp = n; } -/* Splay SP around KEY. */ +/* Bottom up splay of key. */ static void splay_tree_splay (splay_tree sp, splay_tree_key key) @@ -224,8 +143,61 @@ splay_tree_splay (splay_tree sp, splay_tree_key key) if (sp->root == 0) return; - splay_tree_splay_helper (sp, key, &sp->root, - /*grandparent=*/0, /*parent=*/0); + do { + int cmp1, cmp2; + splay_tree_node n, c; + + n = sp->root; + cmp1 = (*sp->comp) (key, n->key); + + /* Found. */ + if (cmp1 == 0) + return; + + /* Left or right? If no child, then we're done. */ + if (cmp1 < 0) + c = n->left; + else + c = n->right; + if (!c) + return; + + /* Next one left or right? If found or no child, we're done + after one rotation. */ + cmp2 = (*sp->comp) (key, c->key); + if (cmp2 == 0 + || (cmp2 < 0 && !c->left) + || (cmp2 > 0 && !c->right)) + { + if (cmp1 < 0) + rotate_left (&sp->root, n, c); + else + rotate_right (&sp->root, n, c); + return; + } + + /* Now we have the four cases of double-rotation. */ + if (cmp1 < 0 && cmp2 < 0) + { + rotate_left (&n->left, c, c->left); + rotate_left (&sp->root, n, n->left); + } + else if (cmp1 > 0 && cmp2 > 0) + { + rotate_right (&n->right, c, c->right); + rotate_right (&sp->root, n, n->right); + } + else if (cmp1 < 0 && cmp2 > 0) + { + rotate_right (&n->left, c, c->right); + rotate_left (&sp->root, n, n->left); + } + else if (cmp1 > 0 && cmp2 < 0) + { + rotate_left (&n->right, c, c->left); + rotate_right (&sp->root, n, n->right); + } + } while (1); } /* Call FN, passing it the DATA, for every node below NODE, all of @@ -234,25 +206,51 @@ splay_tree_splay (splay_tree sp, splay_tree_key key) value is returned. Otherwise, this function returns 0. */ static int -splay_tree_foreach_helper (splay_tree sp, splay_tree_node node, +splay_tree_foreach_helper (splay_tree_node node, splay_tree_foreach_fn fn, void *data) { int val; + splay_tree_node *stack; + int stack_ptr, stack_size; - if (!node) - return 0; + /* A non-recursive implementation is used to avoid filling the stack + for large trees. Splay trees are worst case O(n) in the depth of + the tree. */ - val = splay_tree_foreach_helper (sp, node->left, fn, data); - if (val) - return val; +#define INITIAL_STACK_SIZE 100 + stack_size = INITIAL_STACK_SIZE; + stack_ptr = 0; + stack = XNEWVEC (splay_tree_node, stack_size); + val = 0; - val = (*fn)(node, data); - if (val) - return val; + for (;;) + { + while (node != NULL) + { + if (stack_ptr == stack_size) + { + stack_size *= 2; + stack = XRESIZEVEC (splay_tree_node, stack, stack_size); + } + stack[stack_ptr++] = node; + node = node->left; + } - return splay_tree_foreach_helper (sp, node->right, fn, data); -} + if (stack_ptr == 0) + break; + node = stack[--stack_ptr]; + + val = (*fn) (node, data); + if (val) + break; + + node = node->right; + } + + XDELETEVEC (stack); + return val; +} /* An allocator and deallocator based on xmalloc. */ static void * @@ -296,13 +294,57 @@ splay_tree_new_with_allocator (splay_tree_compare_fn compare_fn, splay_tree_deallocate_fn deallocate_fn, void *allocate_data) { - splay_tree sp = (splay_tree) (*allocate_fn) (sizeof (struct splay_tree_s), - allocate_data); + return + splay_tree_new_typed_alloc (compare_fn, delete_key_fn, delete_value_fn, + allocate_fn, allocate_fn, deallocate_fn, + allocate_data); +} + +/* + +@deftypefn Supplemental splay_tree splay_tree_new_with_typed_alloc @ +(splay_tree_compare_fn @var{compare_fn}, @ +splay_tree_delete_key_fn @var{delete_key_fn}, @ +splay_tree_delete_value_fn @var{delete_value_fn}, @ +splay_tree_allocate_fn @var{tree_allocate_fn}, @ +splay_tree_allocate_fn @var{node_allocate_fn}, @ +splay_tree_deallocate_fn @var{deallocate_fn}, @ +void * @var{allocate_data}) + +This function creates a splay tree that uses two different allocators +@var{tree_allocate_fn} and @var{node_allocate_fn} to use for allocating the +tree itself and its nodes respectively. This is useful when variables of +different types need to be allocated with different allocators. + +The splay tree will use @var{compare_fn} to compare nodes, +@var{delete_key_fn} to deallocate keys, and @var{delete_value_fn} to +deallocate values. Keys and values will be deallocated when the +tree is deleted using splay_tree_delete or when a node is removed +using splay_tree_remove. splay_tree_insert will release the previously +inserted key and value using @var{delete_key_fn} and @var{delete_value_fn} +if the inserted key is already found in the tree. + +@end deftypefn + +*/ + +splay_tree +splay_tree_new_typed_alloc (splay_tree_compare_fn compare_fn, + splay_tree_delete_key_fn delete_key_fn, + splay_tree_delete_value_fn delete_value_fn, + splay_tree_allocate_fn tree_allocate_fn, + splay_tree_allocate_fn node_allocate_fn, + splay_tree_deallocate_fn deallocate_fn, + void * allocate_data) +{ + splay_tree sp = (splay_tree) (*tree_allocate_fn) + (sizeof (struct splay_tree_s), allocate_data); + sp->root = 0; sp->comp = compare_fn; sp->delete_key = delete_key_fn; sp->delete_value = delete_value_fn; - sp->allocate = allocate_fn; + sp->allocate = node_allocate_fn; sp->deallocate = deallocate_fn; sp->allocate_data = allocate_data; @@ -334,20 +376,23 @@ splay_tree_insert (splay_tree sp, splay_tree_key key, splay_tree_value value) if (sp->root && comparison == 0) { - /* If the root of the tree already has the indicated KEY, just - replace the value with VALUE. */ + /* If the root of the tree already has the indicated KEY, delete + the old key and old value, and replace them with KEY and VALUE. */ + if (sp->delete_key) + (*sp->delete_key) (sp->root->key); if (sp->delete_value) (*sp->delete_value)(sp->root->value); + sp->root->key = key; sp->root->value = value; } else { /* Create a new node, and insert it at the root. */ splay_tree_node node; - + node = ((splay_tree_node) - (*sp->allocate) (sizeof (struct splay_tree_node_s), - sp->allocate_data)); + (*sp->allocate) (sizeof (struct splay_tree_node_s), + sp->allocate_data)); node->key = key; node->value = value; @@ -387,6 +432,8 @@ splay_tree_remove (splay_tree sp, splay_tree_key key) right = sp->root->right; /* Delete the root node itself. */ + if (sp->delete_key) + (*sp->delete_key) (sp->root->key); if (sp->delete_value) (*sp->delete_value) (sp->root->value); (*sp->deallocate) (sp->root, sp->allocate_data); @@ -527,7 +574,7 @@ splay_tree_successor (splay_tree sp, splay_tree_key key) int splay_tree_foreach (splay_tree sp, splay_tree_foreach_fn fn, void *data) { - return splay_tree_foreach_helper (sp, sp->root, fn, data); + return splay_tree_foreach_helper (sp->root, fn, data); } /* Splay-tree comparison function, treating the keys as ints. */ @@ -555,3 +602,19 @@ splay_tree_compare_pointers (splay_tree_key k1, splay_tree_key k2) else return 0; } + +/* Splay-tree comparison function, treating the keys as strings. */ + +int +splay_tree_compare_strings (splay_tree_key k1, splay_tree_key k2) +{ + return strcmp ((char *) k1, (char *) k2); +} + +/* Splay-tree delete function, simply using free. */ + +void +splay_tree_delete_pointers (splay_tree_value value) +{ + free ((void *) value); +}