/* A type-safe hash table template.
- Copyright (C) 2012-2014 Free Software Foundation, Inc.
+ Copyright (C) 2012-2019 Free Software Foundation, Inc.
Contributed by Lawrence Crowl <crowl@google.com>
This file is part of GCC.
- A typedef named 'value_type' to the value type (from above).
- A static member function named 'hash' that takes a value_type
- pointer and returns a hashval_t value.
+ (or 'const value_type &') and returns a hashval_t value.
- - A typedef named 'compare_type' that is used to test when an value
+ - A typedef named 'compare_type' that is used to test when a value
is found. This type is the comparison type. Usually, it will be the
same as value_type. If it is not the same type, you must generally
explicitly compute hash values and pass them to the hash table.
- A static member function named 'equal' that takes a value_type
- pointer and a compare_type pointer, and returns a bool.
+ and a compare_type, and returns a bool. Both arguments can be
+ const references.
- A static function named 'remove' that takes an value_type pointer
and frees the memory allocated by it. This function is used when
individual elements of the table need to be disposed of (e.g.,
when deleting a hash table, removing elements from the table, etc).
+ - An optional static function named 'keep_cache_entry'. This
+ function is provided only for garbage-collected elements that
+ are not marked by the normal gc mark pass. It describes what
+ what should happen to the element at the end of the gc mark phase.
+ The return value should be:
+ - 0 if the element should be deleted
+ - 1 if the element should be kept and needs to be marked
+ - -1 if the element should be kept and is already marked.
+ Returning -1 rather than 1 is purely an optimization.
+
3. The type of the hash table itself. (More later.)
In very special circumstances, users may need to know about a fourth type.
4. The template type used to describe how hash table memory
is allocated. This type is called the allocator type. It is
- parameterized on the value type. It provides four functions.
+ parameterized on the value type. It provides two functions:
- A static member function named 'data_alloc'. This function
allocates the data elements in the table.
We compose this into a few steps.
1. Decide on a removal policy for values stored in the table.
- This header provides class templates for the two most common
- policies.
+ hash-traits.h provides class templates for the four most common
+ policies:
* typed_free_remove implements the static 'remove' member function
by calling free().
* typed_noop_remove implements the static 'remove' member function
by doing nothing.
+ * ggc_remove implements the static 'remove' member by doing nothing,
+ but instead provides routines for gc marking and for PCH streaming.
+ Use this for garbage-collected data that needs to be preserved across
+ collections.
+
+ * ggc_cache_remove is like ggc_remove, except that it does not
+ mark the entries during the normal gc mark phase. Instead it
+ uses 'keep_cache_entry' (described above) to keep elements that
+ were not collected and delete those that were. Use this for
+ garbage-collected caches that should not in themselves stop
+ the data from being collected.
+
You can use these policies by simply deriving the descriptor type
from one of those class template, with the appropriate argument.
2. Choose a hash function. Write the static 'hash' member function.
- 3. Choose an equality testing function. In most cases, its two
- arguments will be value_type pointers. If not, the first argument must
- be a value_type pointer, and the second argument a compare_type pointer.
+ 3. Decide whether the lookup function should take as input an object
+ of type value_type or something more restricted. Define compare_type
+ accordingly.
+
+ 4. Choose an equality testing function 'equal' that compares a value_type
+ and a compare_type.
+ If your elements are pointers, it is usually easiest to start with one
+ of the generic pointer descriptors described below and override the bits
+ you need to change.
AN EXAMPLE DESCRIPTOR TYPE
Suppose you want to put some_type into the hash table. You could define
the descriptor type as follows.
- struct some_type_hasher : typed_noop_remove <some_type>
- // Deriving from typed_noop_remove means that we get a 'remove' that does
+ struct some_type_hasher : nofree_ptr_hash <some_type>
+ // Deriving from nofree_ptr_hash means that we get a 'remove' that does
// nothing. This choice is good for raw values.
{
- typedef some_type value_type;
- typedef some_type compare_type;
static inline hashval_t hash (const value_type *);
static inline bool equal (const value_type *, const compare_type *);
};
There is no need to mention some_type directly, as the hash table will
obtain it using some_type_hasher::value_type.
- You can then used any of the functions in hash_table's public interface.
+ You can then use any of the functions in hash_table's public interface.
See hash_table for details. The interface is very similar to libiberty's
htab_t.
+ If a hash table is used only in some rare cases, it is possible
+ to construct the hash_table lazily before first use. This is done
+ through:
+
+ hash_table <some_type_hasher, true> some_type_hash_table;
+
+ which will cause whatever methods actually need the allocated entries
+ array to allocate it later.
+
EASY DESCRIPTORS FOR POINTERS
- The class template pointer_hash provides everything you need to hash
- pointers (as opposed to what they point to). So, to instantiate a hash
- table over pointers to whatever_type,
+ There are four descriptors for pointer elements, one for each of
+ the removal policies above:
+
+ * nofree_ptr_hash (based on typed_noop_remove)
+ * free_ptr_hash (based on typed_free_remove)
+ * ggc_ptr_hash (based on ggc_remove)
+ * ggc_cache_ptr_hash (based on ggc_cache_remove)
- hash_table <pointer_hash <whatever_type>> whatever_type_hash_table;
+ These descriptors hash and compare elements by their pointer value,
+ rather than what they point to. So, to instantiate a hash table over
+ pointers to whatever_type, without freeing the whatever_types, use:
+
+ hash_table <nofree_ptr_hash <whatever_type> > whatever_type_hash_table;
HASH TABLE ITERATORS
#ifndef TYPED_HASHTAB_H
#define TYPED_HASHTAB_H
+#include "statistics.h"
#include "ggc.h"
+#include "vec.h"
#include "hashtab.h"
-#include <new>
+#include "inchash.h"
+#include "mem-stats-traits.h"
+#include "hash-traits.h"
+#include "hash-map-traits.h"
template<typename, typename, typename> class hash_map;
-template<typename, typename> class hash_set;
-
-/* The ordinary memory allocator. */
-/* FIXME (crowl): This allocator may be extracted for wider sharing later. */
-
-template <typename Type>
-struct xcallocator
-{
- static Type *data_alloc (size_t count);
- static void data_free (Type *memory);
-};
-
-
-/* Allocate memory for COUNT data blocks. */
-
-template <typename Type>
-inline Type *
-xcallocator <Type>::data_alloc (size_t count)
-{
- return static_cast <Type *> (xcalloc (count, sizeof (Type)));
-}
-
-
-/* Free memory for data blocks. */
-
-template <typename Type>
-inline void
-xcallocator <Type>::data_free (Type *memory)
-{
- return ::free (memory);
-}
-
-
-/* Helpful type for removing with free. */
-
-template <typename Type>
-struct typed_free_remove
-{
- static inline void remove (Type *p);
-};
-
-
-/* Remove with free. */
-
-template <typename Type>
-inline void
-typed_free_remove <Type>::remove (Type *p)
-{
- free (p);
-}
-
-
-/* Helpful type for a no-op remove. */
-
-template <typename Type>
-struct typed_noop_remove
-{
- static inline void remove (Type *p);
-};
-
-
-/* Remove doing nothing. */
-
-template <typename Type>
-inline void
-typed_noop_remove <Type>::remove (Type *p ATTRIBUTE_UNUSED)
-{
-}
-
-
-/* Pointer hash with a no-op remove method. */
-
-template <typename Type>
-struct pointer_hash : typed_noop_remove <Type>
-{
- typedef Type *value_type;
- typedef Type *compare_type;
- typedef int store_values_directly;
-
- static inline hashval_t hash (const value_type &);
-
- static inline bool equal (const value_type &existing,
- const compare_type &candidate);
-};
-
-template <typename Type>
-inline hashval_t
-pointer_hash <Type>::hash (const value_type &candidate)
-{
- /* This is a really poor hash function, but it is what the current code uses,
- so I am reusing it to avoid an additional axis in testing. */
- return (hashval_t) ((intptr_t)candidate >> 3);
-}
-
-template <typename Type>
-inline bool
-pointer_hash <Type>::equal (const value_type &existing,
- const compare_type &candidate)
-{
- return existing == candidate;
-}
-
-/* Hasher for entry in gc memory. */
-
-template<typename T>
-struct ggc_hasher
-{
- typedef T value_type;
- typedef T compare_type;
- typedef int store_values_directly;
-
- static void remove (T) {}
-
- static void
- ggc_mx (T p)
- {
- extern void gt_ggc_mx (T &);
- gt_ggc_mx (p);
- }
-
- static void
- pch_nx (T &p)
- {
- extern void gt_pch_nx (T &);
- gt_pch_nx (p);
- }
-
- static void
- pch_nx (T &p, gt_pointer_operator op, void *cookie)
- {
- op (&p, cookie);
- }
-};
-
-/* Hasher for cache entry in gc memory. */
-
-template<typename T>
-struct ggc_cache_hasher
-{
- typedef T value_type;
- typedef T compare_type;
- typedef int store_values_directly;
-
- static void remove (T &) {}
-
- /* Entries are weakly held because this is for caches. */
-
- static void ggc_mx (T &) {}
-
- static void
- pch_nx (T &p)
- {
- extern void gt_pch_nx (T &);
- gt_pch_nx (p);
- }
-
- static void
- pch_nx (T &p, gt_pointer_operator op, void *cookie)
- {
- op (&p, cookie);
- }
-
- /* Clear out entries if they are about to be gc'd. */
-
- static void
- handle_cache_entry (T &e)
- {
- if (e != HTAB_EMPTY_ENTRY && e != HTAB_DELETED_ENTRY && !ggc_marked_p (e))
- e = static_cast<T> (HTAB_DELETED_ENTRY);
- }
-};
-
-
-/* Table of primes and their inversion information. */
-
-struct prime_ent
-{
- hashval_t prime;
- hashval_t inv;
- hashval_t inv_m2; /* inverse of prime-2 */
- hashval_t shift;
-};
-
-extern struct prime_ent const prime_tab[];
-
+template<typename, bool, typename> class hash_set;
-/* Functions for computing hash table indexes. */
-
-extern unsigned int hash_table_higher_prime_index (unsigned long n)
- ATTRIBUTE_PURE;
-
-/* Return X % Y using multiplicative inverse values INV and SHIFT.
-
- The multiplicative inverses computed above are for 32-bit types,
- and requires that we be able to compute a highpart multiply.
-
- FIX: I am not at all convinced that
- 3 loads, 2 multiplications, 3 shifts, and 3 additions
- will be faster than
- 1 load and 1 modulus
- on modern systems running a compiler. */
-
-inline hashval_t
-mul_mod (hashval_t x, hashval_t y, hashval_t inv, int shift)
-{
- hashval_t t1, t2, t3, t4, q, r;
-
- t1 = ((uint64_t)x * inv) >> 32;
- t2 = x - t1;
- t3 = t2 >> 1;
- t4 = t1 + t3;
- q = t4 >> shift;
- r = x - (q * y);
-
- return r;
-}
-
-/* Compute the primary table index for HASH given current prime index. */
-
-inline hashval_t
-hash_table_mod1 (hashval_t hash, unsigned int index)
-{
- const struct prime_ent *p = &prime_tab[index];
- gcc_checking_assert (sizeof (hashval_t) * CHAR_BIT <= 32);
- return mul_mod (hash, p->prime, p->inv, p->shift);
-}
-
-/* Compute the secondary table index for HASH given current prime index. */
-
-inline hashval_t
-hash_table_mod2 (hashval_t hash, unsigned int index)
-{
- const struct prime_ent *p = &prime_tab[index];
- gcc_checking_assert (sizeof (hashval_t) * CHAR_BIT <= 32);
- return 1 + mul_mod (hash, p->prime - 2, p->inv_m2, p->shift);
-}
-
-/* The below is some template meta programming to decide if we should use the
- hash table partial specialization that directly stores value_type instead of
- pointers to value_type. If the Descriptor type defines the type
- Descriptor::store_values_directly then values are stored directly otherwise
- pointers to them are stored. */
-template<typename T> struct notype { typedef void type; };
-
-template<typename T, typename = void>
-struct storage_tester
-{
- static const bool value = false;
-};
-
-template<typename T>
-struct storage_tester<T, typename notype<typename
- T::store_values_directly>::type>
-{
- static const bool value = true;
-};
-
- template<typename Traits>
- struct has_is_deleted
-{
- template<typename U, bool (*)(U &)> struct helper {};
- template<typename U> static char test (helper<U, U::is_deleted> *);
- template<typename U> static int test (...);
- static const bool value = sizeof (test<Traits> (0)) == sizeof (char);
-};
-
-template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value>
-struct is_deleted_helper
-{
- static inline bool
- call (Type &v)
- {
- return Traits::is_deleted (v);
- }
-};
-
-template<typename Type, typename Traits>
-struct is_deleted_helper<Type *, Traits, false>
-{
- static inline bool
- call (Type *v)
- {
- return v == HTAB_DELETED_ENTRY;
- }
-};
-
- template<typename Traits>
- struct has_is_empty
-{
- template<typename U, bool (*)(U &)> struct helper {};
- template<typename U> static char test (helper<U, U::is_empty> *);
- template<typename U> static int test (...);
- static const bool value = sizeof (test<Traits> (0)) == sizeof (char);
-};
-
-template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value>
-struct is_empty_helper
-{
- static inline bool
- call (Type &v)
- {
- return Traits::is_empty (v);
- }
-};
-
-template<typename Type, typename Traits>
-struct is_empty_helper<Type *, Traits, false>
-{
- static inline bool
- call (Type *v)
- {
- return v == HTAB_EMPTY_ENTRY;
- }
-};
-
- template<typename Traits>
- struct has_mark_deleted
-{
- template<typename U, void (*)(U &)> struct helper {};
- template<typename U> static char test (helper<U, U::mark_deleted> *);
- template<typename U> static int test (...);
- static const bool value = sizeof (test<Traits> (0)) == sizeof (char);
-};
-
-template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value>
-struct mark_deleted_helper
-{
- static inline void
- call (Type &v)
- {
- Traits::mark_deleted (v);
- }
-};
-
-template<typename Type, typename Traits>
-struct mark_deleted_helper<Type *, Traits, false>
-{
- static inline void
- call (Type *&v)
- {
- v = static_cast<Type *> (HTAB_DELETED_ENTRY);
- }
-};
-
- template<typename Traits>
- struct has_mark_empty
-{
- template<typename U, void (*)(U &)> struct helper {};
- template<typename U> static char test (helper<U, U::mark_empty> *);
- template<typename U> static int test (...);
- static const bool value = sizeof (test<Traits> (0)) == sizeof (char);
-};
-
-template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value>
-struct mark_empty_helper
-{
- static inline void
- call (Type &v)
- {
- Traits::mark_empty (v);
- }
-};
-
-template<typename Type, typename Traits>
-struct mark_empty_helper<Type *, Traits, false>
-{
- static inline void
- call (Type *&v)
- {
- v = static_cast<Type *> (HTAB_EMPTY_ENTRY);
- }
-};
-
-/* User-facing hash table type.
-
- The table stores elements of type Descriptor::value_type, or pointers to
- objects of type value_type if the descriptor does not define the type
- store_values_directly.
-
- It hashes values with the hash member function.
- The table currently works with relatively weak hash functions.
- Use typed_pointer_hash <Value> when hashing pointers instead of objects.
-
- It compares elements with the equal member function.
- Two elements with the same hash may not be equal.
- Use typed_pointer_equal <Value> when hashing pointers instead of objects.
-
- It removes elements with the remove member function.
- This feature is useful for freeing memory.
- Derive from typed_null_remove <Value> when not freeing objects.
- Derive from typed_free_remove <Value> when doing a simple object free.
-
- Specify the template Allocator to allocate and free memory.
- The default is xcallocator.
-
- Storage is an implementation detail and should not be used outside the
- hash table code.
-
-*/
-template <typename Descriptor,
- template<typename Type> class Allocator= xcallocator,
- bool Storage = storage_tester<Descriptor>::value>
-class hash_table
-{
-};
-
-template <typename Descriptor,
- template<typename Type> class Allocator>
-class hash_table<Descriptor, Allocator, false>
-{
- typedef typename Descriptor::value_type value_type;
- typedef typename Descriptor::compare_type compare_type;
-
-public:
- hash_table (size_t);
- ~hash_table ();
-
- /* Current size (in entries) of the hash table. */
- size_t size () const { return m_size; }
-
- /* Return the current number of elements in this hash table. */
- size_t elements () const { return m_n_elements - m_n_deleted; }
-
- /* Return the current number of elements in this hash table. */
- size_t elements_with_deleted () const { return m_n_elements; }
-
- /* This function clears all entries in the given hash table. */
- void empty ();
-
- /* This function clears a specified SLOT in a hash table. It is
- useful when you've already done the lookup and don't want to do it
- again. */
-
- void clear_slot (value_type **);
-
- /* This function searches for a hash table entry equal to the given
- COMPARABLE element starting with the given HASH value. It cannot
- be used to insert or delete an element. */
- value_type *find_with_hash (const compare_type *, hashval_t);
-
-/* Like find_slot_with_hash, but compute the hash value from the element. */
- value_type *find (const value_type *value)
- {
- return find_with_hash (value, Descriptor::hash (value));
- }
-
- value_type **find_slot (const value_type *value, insert_option insert)
- {
- return find_slot_with_hash (value, Descriptor::hash (value), insert);
- }
-
- /* This function searches for a hash table slot containing an entry
- equal to the given COMPARABLE element and starting with the given
- HASH. To delete an entry, call this with insert=NO_INSERT, then
- call clear_slot on the slot returned (possibly after doing some
- checks). To insert an entry, call this with insert=INSERT, then
- write the value you want into the returned slot. When inserting an
- entry, NULL may be returned if memory allocation fails. */
- value_type **find_slot_with_hash (const compare_type *comparable,
- hashval_t hash, enum insert_option insert);
-
- /* This function deletes an element with the given COMPARABLE value
- from hash table starting with the given HASH. If there is no
- matching element in the hash table, this function does nothing. */
- void remove_elt_with_hash (const compare_type *, hashval_t);
-
-/* Like remove_elt_with_hash, but compute the hash value from the element. */
- void remove_elt (const value_type *value)
- {
- remove_elt_with_hash (value, Descriptor::hash (value));
- }
-
- /* This function scans over the entire hash table calling CALLBACK for
- each live entry. If CALLBACK returns false, the iteration stops.
- ARGUMENT is passed as CALLBACK's second argument. */
- template <typename Argument,
- int (*Callback) (value_type **slot, Argument argument)>
- void traverse_noresize (Argument argument);
-
- /* Like traverse_noresize, but does resize the table when it is too empty
- to improve effectivity of subsequent calls. */
- template <typename Argument,
- int (*Callback) (value_type **slot, Argument argument)>
- void traverse (Argument argument);
-
- class iterator
- {
- public:
- iterator () : m_slot (NULL), m_limit (NULL) {}
-
- iterator (value_type **slot, value_type **limit) :
- m_slot (slot), m_limit (limit) {}
-
- inline value_type *operator * () { return *m_slot; }
- void slide ();
- inline iterator &operator ++ ();
- bool operator != (const iterator &other) const
- {
- return m_slot != other.m_slot || m_limit != other.m_limit;
- }
-
- private:
- value_type **m_slot;
- value_type **m_limit;
- };
-
- iterator begin () const
- {
- iterator iter (m_entries, m_entries + m_size);
- iter.slide ();
- return iter;
- }
-
- iterator end () const { return iterator (); }
-
- double collisions () const
- {
- return m_searches ? static_cast <double> (m_collisions) / m_searches : 0;
- }
-
-private:
-
- value_type **find_empty_slot_for_expand (hashval_t);
- void expand ();
-
- /* Table itself. */
- typename Descriptor::value_type **m_entries;
-
- size_t m_size;
-
- /* Current number of elements including also deleted elements. */
- size_t m_n_elements;
-
- /* Current number of deleted elements in the table. */
- size_t m_n_deleted;
-
- /* The following member is used for debugging. Its value is number
- of all calls of `htab_find_slot' for the hash table. */
- unsigned int m_searches;
-
- /* The following member is used for debugging. Its value is number
- of collisions fixed for time of work with the hash table. */
- unsigned int m_collisions;
-
- /* Current size (in entries) of the hash table, as an index into the
- table of primes. */
- unsigned int m_size_prime_index;
-};
-
-template<typename Descriptor, template<typename Type> class Allocator>
-hash_table<Descriptor, Allocator, false>::hash_table (size_t size) :
- m_n_elements (0), m_n_deleted (0), m_searches (0), m_collisions (0)
-{
- unsigned int size_prime_index;
-
- size_prime_index = hash_table_higher_prime_index (size);
- size = prime_tab[size_prime_index].prime;
-
- m_entries = Allocator <value_type*> ::data_alloc (size);
- gcc_assert (m_entries != NULL);
- m_size = size;
- m_size_prime_index = size_prime_index;
-}
-
-template<typename Descriptor, template<typename Type> class Allocator>
-hash_table<Descriptor, Allocator, false>::~hash_table ()
-{
- for (size_t i = m_size - 1; i < m_size; i--)
- if (m_entries[i] != HTAB_EMPTY_ENTRY && m_entries[i] != HTAB_DELETED_ENTRY)
- Descriptor::remove (m_entries[i]);
-
- Allocator <value_type *> ::data_free (m_entries);
-}
-
-/* Similar to find_slot, but without several unwanted side effects:
- - Does not call equal when it finds an existing entry.
- - Does not change the count of elements/searches/collisions in the
- hash table.
- This function also assumes there are no deleted entries in the table.
- HASH is the hash value for the element to be inserted. */
-
-template<typename Descriptor, template<typename Type> class Allocator>
-typename hash_table<Descriptor, Allocator, false>::value_type **
-hash_table<Descriptor, Allocator, false>
-::find_empty_slot_for_expand (hashval_t hash)
-{
- hashval_t index = hash_table_mod1 (hash, m_size_prime_index);
- size_t size = m_size;
- value_type **slot = m_entries + index;
- hashval_t hash2;
-
- if (*slot == HTAB_EMPTY_ENTRY)
- return slot;
- gcc_checking_assert (*slot != HTAB_DELETED_ENTRY);
-
- hash2 = hash_table_mod2 (hash, m_size_prime_index);
- for (;;)
- {
- index += hash2;
- if (index >= size)
- index -= size;
-
- slot = m_entries + index;
- if (*slot == HTAB_EMPTY_ENTRY)
- return slot;
- gcc_checking_assert (*slot != HTAB_DELETED_ENTRY);
- }
-}
-
-/* The following function changes size of memory allocated for the
- entries and repeatedly inserts the table elements. The occupancy
- of the table after the call will be about 50%. Naturally the hash
- table must already exist. Remember also that the place of the
- table entries is changed. If memory allocation fails, this function
- will abort. */
-
-template<typename Descriptor, template<typename Type> class Allocator>
-void
-hash_table<Descriptor, Allocator, false>::expand ()
-{
- value_type **oentries = m_entries;
- unsigned int oindex = m_size_prime_index;
- size_t osize = size ();
- value_type **olimit = oentries + osize;
- size_t elts = elements ();
-
- /* Resize only when table after removal of unused elements is either
- too full or too empty. */
- unsigned int nindex;
- size_t nsize;
- if (elts * 2 > osize || (elts * 8 < osize && osize > 32))
- {
- nindex = hash_table_higher_prime_index (elts * 2);
- nsize = prime_tab[nindex].prime;
- }
- else
- {
- nindex = oindex;
- nsize = osize;
- }
-
- value_type **nentries = Allocator <value_type *> ::data_alloc (nsize);
- gcc_assert (nentries != NULL);
- m_entries = nentries;
- m_size = nsize;
- m_size_prime_index = nindex;
- m_n_elements -= m_n_deleted;
- m_n_deleted = 0;
-
- value_type **p = oentries;
- do
- {
- value_type *x = *p;
-
- if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
- {
- value_type **q = find_empty_slot_for_expand (Descriptor::hash (x));
-
- *q = x;
- }
-
- p++;
- }
- while (p < olimit);
-
- Allocator <value_type *> ::data_free (oentries);
-}
-
-template<typename Descriptor, template<typename Type> class Allocator>
-void
-hash_table<Descriptor, Allocator, false>::empty ()
-{
- size_t size = m_size;
- value_type **entries = m_entries;
- int i;
-
- for (i = size - 1; i >= 0; i--)
- if (entries[i] != HTAB_EMPTY_ENTRY && entries[i] != HTAB_DELETED_ENTRY)
- Descriptor::remove (entries[i]);
-
- /* Instead of clearing megabyte, downsize the table. */
- if (size > 1024*1024 / sizeof (PTR))
- {
- int nindex = hash_table_higher_prime_index (1024 / sizeof (PTR));
- int nsize = prime_tab[nindex].prime;
-
- Allocator <value_type *> ::data_free (m_entries);
- m_entries = Allocator <value_type *> ::data_alloc (nsize);
- m_size = nsize;
- m_size_prime_index = nindex;
- }
- else
- memset (entries, 0, size * sizeof (value_type *));
- m_n_deleted = 0;
- m_n_elements = 0;
-}
-
-/* This function clears a specified SLOT in a hash table. It is
- useful when you've already done the lookup and don't want to do it
- again. */
-
-template<typename Descriptor, template<typename Type> class Allocator>
-void
-hash_table<Descriptor, Allocator, false>::clear_slot (value_type **slot)
-{
- gcc_checking_assert (!(slot < m_entries || slot >= m_entries + size ()
- || *slot == HTAB_EMPTY_ENTRY
- || *slot == HTAB_DELETED_ENTRY));
-
- Descriptor::remove (*slot);
-
- *slot = static_cast <value_type *> (HTAB_DELETED_ENTRY);
- m_n_deleted++;
-}
-
-/* This function searches for a hash table entry equal to the given
- COMPARABLE element starting with the given HASH value. It cannot
- be used to insert or delete an element. */
-
-template<typename Descriptor, template<typename Type> class Allocator>
-typename hash_table<Descriptor, Allocator, false>::value_type *
-hash_table<Descriptor, Allocator, false>
-::find_with_hash (const compare_type *comparable, hashval_t hash)
-{
- m_searches++;
- size_t size = m_size;
- hashval_t index = hash_table_mod1 (hash, m_size_prime_index);
-
- value_type *entry = m_entries[index];
- if (entry == HTAB_EMPTY_ENTRY
- || (entry != HTAB_DELETED_ENTRY && Descriptor::equal (entry, comparable)))
- return entry;
-
- hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index);
- for (;;)
- {
- m_collisions++;
- index += hash2;
- if (index >= size)
- index -= size;
-
- entry = m_entries[index];
- if (entry == HTAB_EMPTY_ENTRY
- || (entry != HTAB_DELETED_ENTRY
- && Descriptor::equal (entry, comparable)))
- return entry;
- }
-}
-
-/* This function searches for a hash table slot containing an entry
- equal to the given COMPARABLE element and starting with the given
- HASH. To delete an entry, call this with insert=NO_INSERT, then
- call clear_slot on the slot returned (possibly after doing some
- checks). To insert an entry, call this with insert=INSERT, then
- write the value you want into the returned slot. When inserting an
- entry, NULL may be returned if memory allocation fails. */
+/* The ordinary memory allocator. */
+/* FIXME (crowl): This allocator may be extracted for wider sharing later. */
-template<typename Descriptor, template<typename Type> class Allocator>
-typename hash_table<Descriptor, Allocator, false>::value_type **
-hash_table<Descriptor, Allocator, false>
-::find_slot_with_hash (const compare_type *comparable, hashval_t hash,
- enum insert_option insert)
+template <typename Type>
+struct xcallocator
{
- if (insert == INSERT && m_size * 3 <= m_n_elements * 4)
- expand ();
-
- m_searches++;
+ static Type *data_alloc (size_t count);
+ static void data_free (Type *memory);
+};
- value_type **first_deleted_slot = NULL;
- hashval_t index = hash_table_mod1 (hash, m_size_prime_index);
- hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index);
- value_type *entry = m_entries[index];
- size_t size = m_size;
- if (entry == HTAB_EMPTY_ENTRY)
- goto empty_entry;
- else if (entry == HTAB_DELETED_ENTRY)
- first_deleted_slot = &m_entries[index];
- else if (Descriptor::equal (entry, comparable))
- return &m_entries[index];
- for (;;)
- {
- m_collisions++;
- index += hash2;
- if (index >= size)
- index -= size;
+/* Allocate memory for COUNT data blocks. */
- entry = m_entries[index];
- if (entry == HTAB_EMPTY_ENTRY)
- goto empty_entry;
- else if (entry == HTAB_DELETED_ENTRY)
- {
- if (!first_deleted_slot)
- first_deleted_slot = &m_entries[index];
- }
- else if (Descriptor::equal (entry, comparable))
- return &m_entries[index];
- }
+template <typename Type>
+inline Type *
+xcallocator <Type>::data_alloc (size_t count)
+{
+ return static_cast <Type *> (xcalloc (count, sizeof (Type)));
+}
- empty_entry:
- if (insert == NO_INSERT)
- return NULL;
- if (first_deleted_slot)
- {
- m_n_deleted--;
- *first_deleted_slot = static_cast <value_type *> (HTAB_EMPTY_ENTRY);
- return first_deleted_slot;
- }
+/* Free memory for data blocks. */
- m_n_elements++;
- return &m_entries[index];
+template <typename Type>
+inline void
+xcallocator <Type>::data_free (Type *memory)
+{
+ return ::free (memory);
}
-/* This function deletes an element with the given COMPARABLE value
- from hash table starting with the given HASH. If there is no
- matching element in the hash table, this function does nothing. */
-template<typename Descriptor, template<typename Type> class Allocator>
-void
-hash_table<Descriptor, Allocator, false>
-::remove_elt_with_hash (const compare_type *comparable, hashval_t hash)
+/* Table of primes and their inversion information. */
+
+struct prime_ent
{
- value_type **slot = find_slot_with_hash (comparable, hash, NO_INSERT);
- if (*slot == HTAB_EMPTY_ENTRY)
- return;
+ hashval_t prime;
+ hashval_t inv;
+ hashval_t inv_m2; /* inverse of prime-2 */
+ hashval_t shift;
+};
- Descriptor::remove (*slot);
+extern struct prime_ent const prime_tab[];
- *slot = static_cast <value_type *> (HTAB_DELETED_ENTRY);
- m_n_deleted++;
-}
+/* Limit number of comparisons when calling hash_table<>::verify. */
+extern unsigned int hash_table_sanitize_eq_limit;
-/* This function scans over the entire hash table calling CALLBACK for
- each live entry. If CALLBACK returns false, the iteration stops.
- ARGUMENT is passed as CALLBACK's second argument. */
+/* Functions for computing hash table indexes. */
-template<typename Descriptor, template<typename Type> class Allocator>
-template<typename Argument,
- int (*Callback) (typename hash_table<Descriptor, Allocator,
- false>::value_type **slot,
- Argument argument)>
-void
-hash_table<Descriptor, Allocator, false>::traverse_noresize (Argument argument)
-{
- value_type **slot = m_entries;
- value_type **limit = slot + size ();
+extern unsigned int hash_table_higher_prime_index (unsigned long n)
+ ATTRIBUTE_PURE;
- do
- {
- value_type *x = *slot;
+/* Return X % Y using multiplicative inverse values INV and SHIFT.
- if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
- if (! Callback (slot, argument))
- break;
- }
- while (++slot < limit);
-}
+ The multiplicative inverses computed above are for 32-bit types,
+ and requires that we be able to compute a highpart multiply.
-/* Like traverse_noresize, but does resize the table when it is too empty
- to improve effectivity of subsequent calls. */
+ FIX: I am not at all convinced that
+ 3 loads, 2 multiplications, 3 shifts, and 3 additions
+ will be faster than
+ 1 load and 1 modulus
+ on modern systems running a compiler. */
-template <typename Descriptor,
- template <typename Type> class Allocator>
-template <typename Argument,
- int (*Callback) (typename hash_table<Descriptor, Allocator,
- false>::value_type **slot,
- Argument argument)>
-void
-hash_table<Descriptor, Allocator, false>::traverse (Argument argument)
+inline hashval_t
+mul_mod (hashval_t x, hashval_t y, hashval_t inv, int shift)
{
- size_t size = m_size;
- if (elements () * 8 < size && size > 32)
- expand ();
+ hashval_t t1, t2, t3, t4, q, r;
- traverse_noresize <Argument, Callback> (argument);
+ t1 = ((uint64_t)x * inv) >> 32;
+ t2 = x - t1;
+ t3 = t2 >> 1;
+ t4 = t1 + t3;
+ q = t4 >> shift;
+ r = x - (q * y);
+
+ return r;
}
-/* Slide down the iterator slots until an active entry is found. */
+/* Compute the primary table index for HASH given current prime index. */
-template<typename Descriptor, template<typename Type> class Allocator>
-void
-hash_table<Descriptor, Allocator, false>::iterator::slide ()
+inline hashval_t
+hash_table_mod1 (hashval_t hash, unsigned int index)
{
- for ( ; m_slot < m_limit; ++m_slot )
- {
- value_type *x = *m_slot;
- if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
- return;
- }
- m_slot = NULL;
- m_limit = NULL;
+ const struct prime_ent *p = &prime_tab[index];
+ gcc_checking_assert (sizeof (hashval_t) * CHAR_BIT <= 32);
+ return mul_mod (hash, p->prime, p->inv, p->shift);
}
-/* Bump the iterator. */
+/* Compute the secondary table index for HASH given current prime index. */
-template<typename Descriptor, template<typename Type> class Allocator>
-inline typename hash_table<Descriptor, Allocator, false>::iterator &
-hash_table<Descriptor, Allocator, false>::iterator::operator ++ ()
+inline hashval_t
+hash_table_mod2 (hashval_t hash, unsigned int index)
{
- ++m_slot;
- slide ();
- return *this;
+ const struct prime_ent *p = &prime_tab[index];
+ gcc_checking_assert (sizeof (hashval_t) * CHAR_BIT <= 32);
+ return 1 + mul_mod (hash, p->prime - 2, p->inv_m2, p->shift);
}
-/* A partial specialization used when values should be stored directly. */
+class mem_usage;
-template <typename Descriptor,
- template<typename Type> class Allocator>
-class hash_table<Descriptor, Allocator, true>
+/* User-facing hash table type.
+
+ The table stores elements of type Descriptor::value_type and uses
+ the static descriptor functions described at the top of the file
+ to hash, compare and remove elements.
+
+ Specify the template Allocator to allocate and free memory.
+ The default is xcallocator.
+
+ Storage is an implementation detail and should not be used outside the
+ hash table code.
+
+*/
+template <typename Descriptor, bool Lazy = false,
+ template<typename Type> class Allocator = xcallocator>
+class hash_table
{
typedef typename Descriptor::value_type value_type;
typedef typename Descriptor::compare_type compare_type;
public:
- explicit hash_table (size_t, bool ggc = false);
+ explicit hash_table (size_t, bool ggc = false,
+ bool sanitize_eq_and_hash = true,
+ bool gather_mem_stats = GATHER_STATISTICS,
+ mem_alloc_origin origin = HASH_TABLE_ORIGIN
+ CXX_MEM_STAT_INFO);
+ explicit hash_table (const hash_table &, bool ggc = false,
+ bool sanitize_eq_and_hash = true,
+ bool gather_mem_stats = GATHER_STATISTICS,
+ mem_alloc_origin origin = HASH_TABLE_ORIGIN
+ CXX_MEM_STAT_INFO);
~hash_table ();
/* Create a hash_table in gc memory. */
-
static hash_table *
- create_ggc (size_t n)
+ create_ggc (size_t n, bool sanitize_eq_and_hash = true CXX_MEM_STAT_INFO)
{
hash_table *table = ggc_alloc<hash_table> ();
- new (table) hash_table (n, true);
+ new (table) hash_table (n, true, sanitize_eq_and_hash, GATHER_STATISTICS,
+ HASH_TABLE_ORIGIN PASS_MEM_STAT);
return table;
}
/* Return the current number of elements in this hash table. */
size_t elements_with_deleted () const { return m_n_elements; }
- /* This function clears all entries in the given hash table. */
- void empty ();
+ /* This function clears all entries in this hash table. */
+ void empty () { if (elements ()) empty_slow (); }
+
+ /* Return true when there are no elements in this hash table. */
+ bool is_empty () const { return elements () == 0; }
/* This function clears a specified SLOT in a hash table. It is
useful when you've already done the lookup and don't want to do it
again. */
-
void clear_slot (value_type *);
/* This function searches for a hash table entry equal to the given
be used to insert or delete an element. */
value_type &find_with_hash (const compare_type &, hashval_t);
-/* Like find_slot_with_hash, but compute the hash value from the element. */
+ /* Like find_slot_with_hash, but compute the hash value from the element. */
value_type &find (const value_type &value)
{
return find_with_hash (value, Descriptor::hash (value));
write the value you want into the returned slot. When inserting an
entry, NULL may be returned if memory allocation fails. */
value_type *find_slot_with_hash (const compare_type &comparable,
- hashval_t hash, enum insert_option insert);
+ hashval_t hash, enum insert_option insert);
/* This function deletes an element with the given COMPARABLE value
from hash table starting with the given HASH. If there is no
matching element in the hash table, this function does nothing. */
void remove_elt_with_hash (const compare_type &, hashval_t);
-/* Like remove_elt_with_hash, but compute the hash value from the element. */
+ /* Like remove_elt_with_hash, but compute the hash value from the
+ element. */
void remove_elt (const value_type &value)
{
remove_elt_with_hash (value, Descriptor::hash (value));
iterator begin () const
{
+ if (Lazy && m_entries == NULL)
+ return iterator ();
iterator iter (m_entries, m_entries + m_size);
iter.slide ();
return iter;
hashtab_entry_note_pointers (void *, void *, gt_pointer_operator, void *);
template<typename T, typename U, typename V> friend void
gt_pch_nx (hash_map<T, U, V> *, gt_pointer_operator, void *);
- template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *,
- gt_pointer_operator,
- void *);
+ template<typename T, typename U>
+ friend void gt_pch_nx (hash_set<T, false, U> *, gt_pointer_operator, void *);
template<typename T> friend void gt_pch_nx (hash_table<T> *,
gt_pointer_operator, void *);
- value_type *alloc_entries (size_t n) const;
+ template<typename T> friend void gt_cleare_cache (hash_table<T> *);
+
+ void empty_slow ();
+
+ value_type *alloc_entries (size_t n CXX_MEM_STAT_INFO) const;
value_type *find_empty_slot_for_expand (hashval_t);
+ void verify (const compare_type &comparable, hashval_t hash);
+ bool too_empty_p (unsigned int);
void expand ();
static bool is_deleted (value_type &v)
- {
- return is_deleted_helper<value_type, Descriptor>::call (v);
- }
+ {
+ return Descriptor::is_deleted (v);
+ }
+
static bool is_empty (value_type &v)
- {
- return is_empty_helper<value_type, Descriptor>::call (v);
- }
+ {
+ return Descriptor::is_empty (v);
+ }
static void mark_deleted (value_type &v)
- {
- return mark_deleted_helper<value_type, Descriptor>::call (v);
- }
+ {
+ Descriptor::mark_deleted (v);
+ }
static void mark_empty (value_type &v)
- {
- return mark_empty_helper<value_type, Descriptor>::call (v);
- }
+ {
+ Descriptor::mark_empty (v);
+ }
/* Table itself. */
typename Descriptor::value_type *m_entries;
/* if m_entries is stored in ggc memory. */
bool m_ggc;
+
+ /* True if the table should be sanitized for equal and hash functions. */
+ bool m_sanitize_eq_and_hash;
+
+ /* If we should gather memory statistics for the table. */
+#if GATHER_STATISTICS
+ bool m_gather_mem_stats;
+#else
+ static const bool m_gather_mem_stats = false;
+#endif
};
-template<typename Descriptor, template<typename Type> class Allocator>
-hash_table<Descriptor, Allocator, true>::hash_table (size_t size, bool ggc) :
+/* As mem-stats.h heavily utilizes hash maps (hash tables), we have to include
+ mem-stats.h after hash_table declaration. */
+
+#include "mem-stats.h"
+#include "hash-map.h"
+
+extern mem_alloc_description<mem_usage>& hash_table_usage (void);
+
+/* Support function for statistics. */
+extern void dump_hash_table_loc_statistics (void);
+
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+hash_table<Descriptor, Lazy, Allocator>::hash_table (size_t size, bool ggc,
+ bool sanitize_eq_and_hash,
+ bool gather_mem_stats
+ ATTRIBUTE_UNUSED,
+ mem_alloc_origin origin
+ MEM_STAT_DECL) :
m_n_elements (0), m_n_deleted (0), m_searches (0), m_collisions (0),
- m_ggc (ggc)
+ m_ggc (ggc), m_sanitize_eq_and_hash (sanitize_eq_and_hash)
+#if GATHER_STATISTICS
+ , m_gather_mem_stats (gather_mem_stats)
+#endif
{
unsigned int size_prime_index;
size_prime_index = hash_table_higher_prime_index (size);
size = prime_tab[size_prime_index].prime;
- m_entries = alloc_entries (size);
+ if (m_gather_mem_stats)
+ hash_table_usage ().register_descriptor (this, origin, ggc
+ FINAL_PASS_MEM_STAT);
+
+ if (Lazy)
+ m_entries = NULL;
+ else
+ m_entries = alloc_entries (size PASS_MEM_STAT);
m_size = size;
m_size_prime_index = size_prime_index;
}
-template<typename Descriptor, template<typename Type> class Allocator>
-hash_table<Descriptor, Allocator, true>::~hash_table ()
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+hash_table<Descriptor, Lazy, Allocator>::hash_table (const hash_table &h,
+ bool ggc,
+ bool sanitize_eq_and_hash,
+ bool gather_mem_stats
+ ATTRIBUTE_UNUSED,
+ mem_alloc_origin origin
+ MEM_STAT_DECL) :
+ m_n_elements (h.m_n_elements), m_n_deleted (h.m_n_deleted),
+ m_searches (0), m_collisions (0), m_ggc (ggc),
+ m_sanitize_eq_and_hash (sanitize_eq_and_hash)
+#if GATHER_STATISTICS
+ , m_gather_mem_stats (gather_mem_stats)
+#endif
{
- for (size_t i = m_size - 1; i < m_size; i--)
- if (!is_empty (m_entries[i]) && !is_deleted (m_entries[i]))
- Descriptor::remove (m_entries[i]);
+ size_t size = h.m_size;
- if (!m_ggc)
- Allocator <value_type> ::data_free (m_entries);
+ if (m_gather_mem_stats)
+ hash_table_usage ().register_descriptor (this, origin, ggc
+ FINAL_PASS_MEM_STAT);
+
+ if (Lazy && h.m_entries == NULL)
+ m_entries = NULL;
else
- ggc_free (m_entries);
+ {
+ value_type *nentries = alloc_entries (size PASS_MEM_STAT);
+ for (size_t i = 0; i < size; ++i)
+ {
+ value_type &entry = h.m_entries[i];
+ if (is_deleted (entry))
+ mark_deleted (nentries[i]);
+ else if (!is_empty (entry))
+ nentries[i] = entry;
+ }
+ m_entries = nentries;
+ }
+ m_size = size;
+ m_size_prime_index = h.m_size_prime_index;
+}
+
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+hash_table<Descriptor, Lazy, Allocator>::~hash_table ()
+{
+ if (!Lazy || m_entries)
+ {
+ for (size_t i = m_size - 1; i < m_size; i--)
+ if (!is_empty (m_entries[i]) && !is_deleted (m_entries[i]))
+ Descriptor::remove (m_entries[i]);
+
+ if (!m_ggc)
+ Allocator <value_type> ::data_free (m_entries);
+ else
+ ggc_free (m_entries);
+ if (m_gather_mem_stats)
+ hash_table_usage ().release_instance_overhead (this,
+ sizeof (value_type)
+ * m_size, true);
+ }
+ else if (m_gather_mem_stats)
+ hash_table_usage ().unregister_descriptor (this);
}
/* This function returns an array of empty hash table elements. */
-template<typename Descriptor, template<typename Type> class Allocator>
-inline typename hash_table<Descriptor, Allocator, true>::value_type *
-hash_table<Descriptor, Allocator, true>::alloc_entries (size_t n) const
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+inline typename hash_table<Descriptor, Lazy, Allocator>::value_type *
+hash_table<Descriptor, Lazy,
+ Allocator>::alloc_entries (size_t n MEM_STAT_DECL) const
{
value_type *nentries;
+ if (m_gather_mem_stats)
+ hash_table_usage ().register_instance_overhead (sizeof (value_type) * n, this);
+
if (!m_ggc)
nentries = Allocator <value_type> ::data_alloc (n);
else
- nentries = ::ggc_cleared_vec_alloc<value_type> (n);
+ nentries = ::ggc_cleared_vec_alloc<value_type> (n PASS_MEM_STAT);
gcc_assert (nentries != NULL);
for (size_t i = 0; i < n; i++)
This function also assumes there are no deleted entries in the table.
HASH is the hash value for the element to be inserted. */
-template<typename Descriptor, template<typename Type> class Allocator>
-typename hash_table<Descriptor, Allocator, true>::value_type *
-hash_table<Descriptor, Allocator, true>
-::find_empty_slot_for_expand (hashval_t hash)
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+typename hash_table<Descriptor, Lazy, Allocator>::value_type *
+hash_table<Descriptor, Lazy,
+ Allocator>::find_empty_slot_for_expand (hashval_t hash)
{
hashval_t index = hash_table_mod1 (hash, m_size_prime_index);
size_t size = m_size;
if (is_empty (*slot))
return slot;
-#ifdef ENABLE_CHECKING
gcc_checking_assert (!is_deleted (*slot));
-#endif
hash2 = hash_table_mod2 (hash, m_size_prime_index);
for (;;)
slot = m_entries + index;
if (is_empty (*slot))
return slot;
-#ifdef ENABLE_CHECKING
gcc_checking_assert (!is_deleted (*slot));
-#endif
}
}
+/* Return true if the current table is excessively big for ELTS elements. */
+
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+inline bool
+hash_table<Descriptor, Lazy, Allocator>::too_empty_p (unsigned int elts)
+{
+ return elts * 8 < m_size && m_size > 32;
+}
+
/* The following function changes size of memory allocated for the
entries and repeatedly inserts the table elements. The occupancy
of the table after the call will be about 50%. Naturally the hash
table entries is changed. If memory allocation fails, this function
will abort. */
- template<typename Descriptor, template<typename Type> class Allocator>
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
void
-hash_table<Descriptor, Allocator, true>::expand ()
+hash_table<Descriptor, Lazy, Allocator>::expand ()
{
value_type *oentries = m_entries;
unsigned int oindex = m_size_prime_index;
too full or too empty. */
unsigned int nindex;
size_t nsize;
- if (elts * 2 > osize || (elts * 8 < osize && osize > 32))
+ if (elts * 2 > osize || too_empty_p (elts))
{
nindex = hash_table_higher_prime_index (elts * 2);
nsize = prime_tab[nindex].prime;
}
value_type *nentries = alloc_entries (nsize);
+
+ if (m_gather_mem_stats)
+ hash_table_usage ().release_instance_overhead (this, sizeof (value_type)
+ * osize);
+
m_entries = nentries;
m_size = nsize;
m_size_prime_index = nindex;
ggc_free (oentries);
}
-template<typename Descriptor, template<typename Type> class Allocator>
+/* Implements empty() in cases where it isn't a no-op. */
+
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
void
-hash_table<Descriptor, Allocator, true>::empty ()
+hash_table<Descriptor, Lazy, Allocator>::empty_slow ()
{
size_t size = m_size;
+ size_t nsize = size;
value_type *entries = m_entries;
int i;
Descriptor::remove (entries[i]);
/* Instead of clearing megabyte, downsize the table. */
- if (size > 1024*1024 / sizeof (PTR))
+ if (size > 1024*1024 / sizeof (value_type))
+ nsize = 1024 / sizeof (value_type);
+ else if (too_empty_p (m_n_elements))
+ nsize = m_n_elements * 2;
+
+ if (nsize != size)
{
- int nindex = hash_table_higher_prime_index (1024 / sizeof (PTR));
+ int nindex = hash_table_higher_prime_index (nsize);
int nsize = prime_tab[nindex].prime;
if (!m_ggc)
m_size_prime_index = nindex;
}
else
- memset (entries, 0, size * sizeof (value_type));
+ {
+#ifndef BROKEN_VALUE_INITIALIZATION
+ for ( ; size; ++entries, --size)
+ *entries = value_type ();
+#else
+ memset (entries, 0, size * sizeof (value_type));
+#endif
+ }
m_n_deleted = 0;
m_n_elements = 0;
}
useful when you've already done the lookup and don't want to do it
again. */
-template<typename Descriptor, template<typename Type> class Allocator>
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
void
-hash_table<Descriptor, Allocator, true>::clear_slot (value_type *slot)
+hash_table<Descriptor, Lazy, Allocator>::clear_slot (value_type *slot)
{
gcc_checking_assert (!(slot < m_entries || slot >= m_entries + size ()
|| is_empty (*slot) || is_deleted (*slot)));
COMPARABLE element starting with the given HASH value. It cannot
be used to insert or delete an element. */
-template<typename Descriptor, template<typename Type> class Allocator>
-typename hash_table<Descriptor, Allocator, true>::value_type &
-hash_table<Descriptor, Allocator, true>
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+typename hash_table<Descriptor, Lazy, Allocator>::value_type &
+hash_table<Descriptor, Lazy, Allocator>
::find_with_hash (const compare_type &comparable, hashval_t hash)
{
m_searches++;
size_t size = m_size;
hashval_t index = hash_table_mod1 (hash, m_size_prime_index);
+ if (Lazy && m_entries == NULL)
+ m_entries = alloc_entries (size);
value_type *entry = &m_entries[index];
if (is_empty (*entry)
|| (!is_deleted (*entry) && Descriptor::equal (*entry, comparable)))
entry = &m_entries[index];
if (is_empty (*entry)
|| (!is_deleted (*entry) && Descriptor::equal (*entry, comparable)))
- return *entry;
+ {
+#if CHECKING_P
+ if (m_sanitize_eq_and_hash)
+ verify (comparable, hash);
+#endif
+ return *entry;
+ }
}
}
write the value you want into the returned slot. When inserting an
entry, NULL may be returned if memory allocation fails. */
-template<typename Descriptor, template<typename Type> class Allocator>
-typename hash_table<Descriptor, Allocator, true>::value_type *
-hash_table<Descriptor, Allocator, true>
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+typename hash_table<Descriptor, Lazy, Allocator>::value_type *
+hash_table<Descriptor, Lazy, Allocator>
::find_slot_with_hash (const compare_type &comparable, hashval_t hash,
enum insert_option insert)
{
+ if (Lazy && m_entries == NULL)
+ {
+ if (insert == INSERT)
+ m_entries = alloc_entries (m_size);
+ else
+ return NULL;
+ }
if (insert == INSERT && m_size * 3 <= m_n_elements * 4)
expand ();
- m_searches++;
+#if CHECKING_P
+ if (m_sanitize_eq_and_hash)
+ verify (comparable, hash);
+#endif
+ m_searches++;
value_type *first_deleted_slot = NULL;
hashval_t index = hash_table_mod1 (hash, m_size_prime_index);
hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index);
return &m_entries[index];
}
+/* Report a hash table checking error. */
+
+ATTRIBUTE_NORETURN ATTRIBUTE_COLD
+static void
+hashtab_chk_error ()
+{
+ fprintf (stderr, "hash table checking failed: "
+ "equal operator returns true for a pair "
+ "of values with a different hash value\n");
+ gcc_unreachable ();
+}
+
+/* Verify that all existing elements in th hash table which are
+ equal to COMPARABLE have an equal HASH value provided as argument. */
+
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+void
+hash_table<Descriptor, Lazy, Allocator>
+::verify (const compare_type &comparable, hashval_t hash)
+{
+ for (size_t i = 0; i < MIN (hash_table_sanitize_eq_limit, m_size); i++)
+ {
+ value_type *entry = &m_entries[i];
+ if (!is_empty (*entry) && !is_deleted (*entry)
+ && hash != Descriptor::hash (*entry)
+ && Descriptor::equal (*entry, comparable))
+ hashtab_chk_error ();
+ }
+}
+
/* This function deletes an element with the given COMPARABLE value
from hash table starting with the given HASH. If there is no
matching element in the hash table, this function does nothing. */
-template<typename Descriptor, template<typename Type> class Allocator>
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
void
-hash_table<Descriptor, Allocator, true>
+hash_table<Descriptor, Lazy, Allocator>
::remove_elt_with_hash (const compare_type &comparable, hashval_t hash)
{
value_type *slot = find_slot_with_hash (comparable, hash, NO_INSERT);
- if (is_empty (*slot))
+ if (slot == NULL)
return;
Descriptor::remove (*slot);
each live entry. If CALLBACK returns false, the iteration stops.
ARGUMENT is passed as CALLBACK's second argument. */
-template<typename Descriptor,
+template<typename Descriptor, bool Lazy,
template<typename Type> class Allocator>
template<typename Argument,
- int (*Callback) (typename hash_table<Descriptor, Allocator,
- true>::value_type *slot,
- Argument argument)>
+ int (*Callback)
+ (typename hash_table<Descriptor, Lazy, Allocator>::value_type *slot,
+ Argument argument)>
void
-hash_table<Descriptor, Allocator, true>::traverse_noresize (Argument argument)
+hash_table<Descriptor, Lazy, Allocator>::traverse_noresize (Argument argument)
{
+ if (Lazy && m_entries == NULL)
+ return;
+
value_type *slot = m_entries;
value_type *limit = slot + size ();
/* Like traverse_noresize, but does resize the table when it is too empty
to improve effectivity of subsequent calls. */
-template <typename Descriptor,
+template <typename Descriptor, bool Lazy,
template <typename Type> class Allocator>
template <typename Argument,
- int (*Callback) (typename hash_table<Descriptor, Allocator,
- true>::value_type *slot,
- Argument argument)>
+ int (*Callback)
+ (typename hash_table<Descriptor, Lazy, Allocator>::value_type *slot,
+ Argument argument)>
void
-hash_table<Descriptor, Allocator, true>::traverse (Argument argument)
+hash_table<Descriptor, Lazy, Allocator>::traverse (Argument argument)
{
- size_t size = m_size;
- if (elements () * 8 < size && size > 32)
+ if (too_empty_p (elements ()) && (!Lazy || m_entries))
expand ();
traverse_noresize <Argument, Callback> (argument);
/* Slide down the iterator slots until an active entry is found. */
-template<typename Descriptor, template<typename Type> class Allocator>
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
void
-hash_table<Descriptor, Allocator, true>::iterator::slide ()
+hash_table<Descriptor, Lazy, Allocator>::iterator::slide ()
{
for ( ; m_slot < m_limit; ++m_slot )
{
/* Bump the iterator. */
-template<typename Descriptor, template<typename Type> class Allocator>
-inline typename hash_table<Descriptor, Allocator, true>::iterator &
-hash_table<Descriptor, Allocator, true>::iterator::operator ++ ()
+template<typename Descriptor, bool Lazy,
+ template<typename Type> class Allocator>
+inline typename hash_table<Descriptor, Lazy, Allocator>::iterator &
+hash_table<Descriptor, Lazy, Allocator>::iterator::operator ++ ()
{
++m_slot;
slide ();
|| table::is_deleted (h->m_entries[i]))
continue;
- E::ggc_mx (h->m_entries[i]);
+ /* Use ggc_maxbe_mx so we don't mark right away for cache tables; we'll
+ mark in gt_cleare_cache if appropriate. */
+ E::ggc_maybe_mx (h->m_entries[i]);
}
}
inline void
gt_cleare_cache (hash_table<H> *h)
{
+ typedef hash_table<H> table;
if (!h)
return;
- for (typename hash_table<H>::iterator iter = h->begin (); iter != h->end ();
- ++iter)
- H::handle_cache_entry (*iter);
+ for (typename table::iterator iter = h->begin (); iter != h->end (); ++iter)
+ if (!table::is_empty (*iter) && !table::is_deleted (*iter))
+ {
+ int res = H::keep_cache_entry (*iter);
+ if (res == 0)
+ h->clear_slot (&*iter);
+ else if (res != -1)
+ H::ggc_mx (*iter);
+ }
}
#endif /* TYPED_HASHTAB_H */
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