/* An expandable hash tables datatype.
- Copyright (C) 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 1999-2019 Free Software Foundation, Inc.
Contributed by Vladimir Makarov (vmakarov@cygnus.com).
This file is part of the libiberty library.
You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA. */
/* This package implements basic hash table functionality. It is possible
to search for an entry, create an entry and destroy an entry.
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
-
#ifdef HAVE_STRING_H
#include <string.h>
#endif
-
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
#include <stdio.h>
#include "libiberty.h"
+#include "ansidecl.h"
#include "hashtab.h"
-/* This macro defines reserved value for empty table entry. */
-
-#define EMPTY_ENTRY ((PTR) 0)
-
-/* This macro defines reserved value for table entry which contained
- a deleted element. */
-
-#define DELETED_ENTRY ((PTR) 1)
+#ifndef CHAR_BIT
+#define CHAR_BIT 8
+#endif
-static unsigned long higher_prime_number PARAMS ((unsigned long));
-static hashval_t hash_pointer PARAMS ((const void *));
-static int eq_pointer PARAMS ((const void *, const void *));
-static int htab_expand PARAMS ((htab_t));
-static PTR *find_empty_slot_for_expand PARAMS ((htab_t, hashval_t));
+static unsigned int higher_prime_index (unsigned long);
+static hashval_t htab_mod_1 (hashval_t, hashval_t, hashval_t, int);
+static hashval_t htab_mod (hashval_t, htab_t);
+static hashval_t htab_mod_m2 (hashval_t, htab_t);
+static hashval_t hash_pointer (const void *);
+static int eq_pointer (const void *, const void *);
+static int htab_expand (htab_t);
+static PTR *find_empty_slot_for_expand (htab_t, hashval_t);
/* At some point, we could make these be NULL, and modify the
hash-table routines to handle NULL specially; that would avoid
htab_hash htab_hash_pointer = hash_pointer;
htab_eq htab_eq_pointer = eq_pointer;
-/* The following function returns a nearest prime number which is
- greater than N, and near a power of two. */
-
-static unsigned long
-higher_prime_number (n)
- unsigned long n;
-{
- /* These are primes that are near, but slightly smaller than, a
- power of two. */
- static const unsigned long primes[] = {
- (unsigned long) 7,
- (unsigned long) 13,
- (unsigned long) 31,
- (unsigned long) 61,
- (unsigned long) 127,
- (unsigned long) 251,
- (unsigned long) 509,
- (unsigned long) 1021,
- (unsigned long) 2039,
- (unsigned long) 4093,
- (unsigned long) 8191,
- (unsigned long) 16381,
- (unsigned long) 32749,
- (unsigned long) 65521,
- (unsigned long) 131071,
- (unsigned long) 262139,
- (unsigned long) 524287,
- (unsigned long) 1048573,
- (unsigned long) 2097143,
- (unsigned long) 4194301,
- (unsigned long) 8388593,
- (unsigned long) 16777213,
- (unsigned long) 33554393,
- (unsigned long) 67108859,
- (unsigned long) 134217689,
- (unsigned long) 268435399,
- (unsigned long) 536870909,
- (unsigned long) 1073741789,
- (unsigned long) 2147483647,
- /* 4294967291L */
- ((unsigned long) 2147483647) + ((unsigned long) 2147483644),
- };
-
- const unsigned long *low = &primes[0];
- const unsigned long *high = &primes[sizeof(primes) / sizeof(primes[0])];
+/* Table of primes and multiplicative inverses.
+
+ Note that these are not minimally reduced inverses. Unlike when generating
+ code to divide by a constant, we want to be able to use the same algorithm
+ all the time. All of these inverses (are implied to) have bit 32 set.
+
+ For the record, here's the function that computed the table; it's a
+ vastly simplified version of the function of the same name from gcc. */
+
+#if 0
+unsigned int
+ceil_log2 (unsigned int x)
+{
+ int i;
+ for (i = 31; i >= 0 ; --i)
+ if (x > (1u << i))
+ return i+1;
+ abort ();
+}
+
+unsigned int
+choose_multiplier (unsigned int d, unsigned int *mlp, unsigned char *shiftp)
+{
+ unsigned long long mhigh;
+ double nx;
+ int lgup, post_shift;
+ int pow, pow2;
+ int n = 32, precision = 32;
+
+ lgup = ceil_log2 (d);
+ pow = n + lgup;
+ pow2 = n + lgup - precision;
+
+ nx = ldexp (1.0, pow) + ldexp (1.0, pow2);
+ mhigh = nx / d;
+
+ *shiftp = lgup - 1;
+ *mlp = mhigh;
+ return mhigh >> 32;
+}
+#endif
+
+struct prime_ent
+{
+ hashval_t prime;
+ hashval_t inv;
+ hashval_t inv_m2; /* inverse of prime-2 */
+ hashval_t shift;
+};
+
+static struct prime_ent const prime_tab[] = {
+ { 7, 0x24924925, 0x9999999b, 2 },
+ { 13, 0x3b13b13c, 0x745d1747, 3 },
+ { 31, 0x08421085, 0x1a7b9612, 4 },
+ { 61, 0x0c9714fc, 0x15b1e5f8, 5 },
+ { 127, 0x02040811, 0x0624dd30, 6 },
+ { 251, 0x05197f7e, 0x073260a5, 7 },
+ { 509, 0x01824366, 0x02864fc8, 8 },
+ { 1021, 0x00c0906d, 0x014191f7, 9 },
+ { 2039, 0x0121456f, 0x0161e69e, 10 },
+ { 4093, 0x00300902, 0x00501908, 11 },
+ { 8191, 0x00080041, 0x00180241, 12 },
+ { 16381, 0x000c0091, 0x00140191, 13 },
+ { 32749, 0x002605a5, 0x002a06e6, 14 },
+ { 65521, 0x000f00e2, 0x00110122, 15 },
+ { 131071, 0x00008001, 0x00018003, 16 },
+ { 262139, 0x00014002, 0x0001c004, 17 },
+ { 524287, 0x00002001, 0x00006001, 18 },
+ { 1048573, 0x00003001, 0x00005001, 19 },
+ { 2097143, 0x00004801, 0x00005801, 20 },
+ { 4194301, 0x00000c01, 0x00001401, 21 },
+ { 8388593, 0x00001e01, 0x00002201, 22 },
+ { 16777213, 0x00000301, 0x00000501, 23 },
+ { 33554393, 0x00001381, 0x00001481, 24 },
+ { 67108859, 0x00000141, 0x000001c1, 25 },
+ { 134217689, 0x000004e1, 0x00000521, 26 },
+ { 268435399, 0x00000391, 0x000003b1, 27 },
+ { 536870909, 0x00000019, 0x00000029, 28 },
+ { 1073741789, 0x0000008d, 0x00000095, 29 },
+ { 2147483647, 0x00000003, 0x00000007, 30 },
+ /* Avoid "decimal constant so large it is unsigned" for 4294967291. */
+ { 0xfffffffb, 0x00000006, 0x00000008, 31 }
+};
+
+/* The following function returns an index into the above table of the
+ nearest prime number which is greater than N, and near a power of two. */
+
+static unsigned int
+higher_prime_index (unsigned long n)
+{
+ unsigned int low = 0;
+ unsigned int high = sizeof(prime_tab) / sizeof(prime_tab[0]);
while (low != high)
{
- const unsigned long *mid = low + (high - low) / 2;
- if (n > *mid)
+ unsigned int mid = low + (high - low) / 2;
+ if (n > prime_tab[mid].prime)
low = mid + 1;
else
high = mid;
}
/* If we've run out of primes, abort. */
- if (n > *low)
+ if (n > prime_tab[low].prime)
{
fprintf (stderr, "Cannot find prime bigger than %lu\n", n);
abort ();
}
- return *low;
-}
-
-/* Returns a hash code for P. */
-
-static hashval_t
-hash_pointer (p)
- const PTR p;
-{
- return (hashval_t) ((long)p >> 3);
+ return low;
}
/* Returns non-zero if P1 and P2 are equal. */
static int
-eq_pointer (p1, p2)
- const PTR p1;
- const PTR p2;
+eq_pointer (const PTR p1, const PTR p2)
{
return p1 == p2;
}
-/* Return the current size of given hash table. */
-inline size_t
-htab_size (htab)
- htab_t htab;
+/* The parens around the function names in the next two definitions
+ are essential in order to prevent macro expansions of the name.
+ The bodies, however, are expanded as expected, so they are not
+ recursive definitions. */
+
+/* Return the current size of given hash table. */
+
+#define htab_size(htab) ((htab)->size)
+
+size_t
+(htab_size) (htab_t htab)
{
- return htab->size;
+ return htab_size (htab);
}
/* Return the current number of elements in given hash table. */
-inline size_t
-htab_elements (htab)
- htab_t htab;
+#define htab_elements(htab) ((htab)->n_elements - (htab)->n_deleted)
+
+size_t
+(htab_elements) (htab_t htab)
{
- return htab->n_elements - htab->n_deleted;
+ return htab_elements (htab);
+}
+
+/* Return X % Y. */
+
+static inline hashval_t
+htab_mod_1 (hashval_t x, hashval_t y, hashval_t inv, int shift)
+{
+ /* The multiplicative inverses computed above are for 32-bit types, and
+ requires that we be able to compute a highpart multiply. */
+#ifdef UNSIGNED_64BIT_TYPE
+ __extension__ typedef UNSIGNED_64BIT_TYPE ull;
+ if (sizeof (hashval_t) * CHAR_BIT <= 32)
+ {
+ hashval_t t1, t2, t3, t4, q, r;
+
+ t1 = ((ull)x * inv) >> 32;
+ t2 = x - t1;
+ t3 = t2 >> 1;
+ t4 = t1 + t3;
+ q = t4 >> shift;
+ r = x - (q * y);
+
+ return r;
+ }
+#endif
+
+ /* Otherwise just use the native division routines. */
+ return x % y;
}
/* Compute the primary hash for HASH given HTAB's current size. */
static inline hashval_t
-htab_mod (hash, htab)
- hashval_t hash;
- htab_t htab;
+htab_mod (hashval_t hash, htab_t htab)
{
- return hash % htab_size (htab);
+ const struct prime_ent *p = &prime_tab[htab->size_prime_index];
+ return htab_mod_1 (hash, p->prime, p->inv, p->shift);
}
/* Compute the secondary hash for HASH given HTAB's current size. */
static inline hashval_t
-htab_mod_m2 (hash, htab)
- hashval_t hash;
- htab_t htab;
+htab_mod_m2 (hashval_t hash, htab_t htab)
{
- return 1 + hash % (htab_size (htab) - 2);
+ const struct prime_ent *p = &prime_tab[htab->size_prime_index];
+ return 1 + htab_mod_1 (hash, p->prime - 2, p->inv_m2, p->shift);
}
/* This function creates table with length slightly longer than given
source length. Created hash table is initiated as empty (all the
- hash table entries are EMPTY_ENTRY). The function returns the
+ hash table entries are HTAB_EMPTY_ENTRY). The function returns the
created hash table, or NULL if memory allocation fails. */
htab_t
-htab_create_alloc (size, hash_f, eq_f, del_f, alloc_f, free_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
- htab_alloc alloc_f;
- htab_free free_f;
+htab_create_alloc (size_t size, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, htab_alloc alloc_f, htab_free free_f)
+{
+ return htab_create_typed_alloc (size, hash_f, eq_f, del_f, alloc_f, alloc_f,
+ free_f);
+}
+
+/* As above, but uses the variants of ALLOC_F and FREE_F which accept
+ an extra argument. */
+
+htab_t
+htab_create_alloc_ex (size_t size, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, void *alloc_arg,
+ htab_alloc_with_arg alloc_f,
+ htab_free_with_arg free_f)
{
htab_t result;
+ unsigned int size_prime_index;
+
+ size_prime_index = higher_prime_index (size);
+ size = prime_tab[size_prime_index].prime;
- size = higher_prime_number (size);
- result = (htab_t) (*alloc_f) (1, sizeof (struct htab));
+ result = (htab_t) (*alloc_f) (alloc_arg, 1, sizeof (struct htab));
if (result == NULL)
return NULL;
- result->entries = (PTR *) (*alloc_f) (size, sizeof (PTR));
+ result->entries = (PTR *) (*alloc_f) (alloc_arg, size, sizeof (PTR));
if (result->entries == NULL)
{
if (free_f != NULL)
- (*free_f) (result);
+ (*free_f) (alloc_arg, result);
return NULL;
}
result->size = size;
+ result->size_prime_index = size_prime_index;
result->hash_f = hash_f;
result->eq_f = eq_f;
result->del_f = del_f;
- result->alloc_f = alloc_f;
- result->free_f = free_f;
+ result->alloc_arg = alloc_arg;
+ result->alloc_with_arg_f = alloc_f;
+ result->free_with_arg_f = free_f;
return result;
}
-/* As above, but use the variants of alloc_f and free_f which accept
- an extra argument. */
+/*
+
+@deftypefn Supplemental htab_t htab_create_typed_alloc (size_t @var{size}, @
+htab_hash @var{hash_f}, htab_eq @var{eq_f}, htab_del @var{del_f}, @
+htab_alloc @var{alloc_tab_f}, htab_alloc @var{alloc_f}, @
+htab_free @var{free_f})
+
+This function creates a hash table that uses two different allocators
+@var{alloc_tab_f} and @var{alloc_f} to use for allocating the table itself
+and its entries respectively. This is useful when variables of different
+types need to be allocated with different allocators.
+
+The created hash table is slightly larger than @var{size} and it is
+initially empty (all the hash table entries are @code{HTAB_EMPTY_ENTRY}).
+The function returns the created hash table, or @code{NULL} if memory
+allocation fails.
+
+@end deftypefn
+
+*/
htab_t
-htab_create_alloc_ex (size, hash_f, eq_f, del_f, alloc_arg, alloc_f,
- free_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
- PTR alloc_arg;
- htab_alloc_with_arg alloc_f;
- htab_free_with_arg free_f;
+htab_create_typed_alloc (size_t size, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, htab_alloc alloc_tab_f,
+ htab_alloc alloc_f, htab_free free_f)
{
htab_t result;
+ unsigned int size_prime_index;
- size = higher_prime_number (size);
- result = (htab_t) (*alloc_f) (alloc_arg, 1, sizeof (struct htab));
+ size_prime_index = higher_prime_index (size);
+ size = prime_tab[size_prime_index].prime;
+
+ result = (htab_t) (*alloc_tab_f) (1, sizeof (struct htab));
if (result == NULL)
return NULL;
- result->entries = (PTR *) (*alloc_f) (alloc_arg, size, sizeof (PTR));
+ result->entries = (PTR *) (*alloc_f) (size, sizeof (PTR));
if (result->entries == NULL)
{
if (free_f != NULL)
- (*free_f) (alloc_arg, result);
+ (*free_f) (result);
return NULL;
}
result->size = size;
+ result->size_prime_index = size_prime_index;
result->hash_f = hash_f;
result->eq_f = eq_f;
result->del_f = del_f;
- result->alloc_arg = alloc_arg;
- result->alloc_with_arg_f = alloc_f;
- result->free_with_arg_f = free_f;
+ result->alloc_f = alloc_f;
+ result->free_f = free_f;
return result;
}
+
/* Update the function pointers and allocation parameter in the htab_t. */
void
-htab_set_functions_ex (htab, hash_f, eq_f, del_f, alloc_arg, alloc_f, free_f)
- htab_t htab;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
- PTR alloc_arg;
- htab_alloc_with_arg alloc_f;
- htab_free_with_arg free_f;
+htab_set_functions_ex (htab_t htab, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, PTR alloc_arg,
+ htab_alloc_with_arg alloc_f, htab_free_with_arg free_f)
{
htab->hash_f = hash_f;
htab->eq_f = eq_f;
#undef htab_create
htab_t
-htab_create (size, hash_f, eq_f, del_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
+htab_create (size_t size, htab_hash hash_f, htab_eq eq_f, htab_del del_f)
{
return htab_create_alloc (size, hash_f, eq_f, del_f, xcalloc, free);
}
htab_t
-htab_try_create (size, hash_f, eq_f, del_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
+htab_try_create (size_t size, htab_hash hash_f, htab_eq eq_f, htab_del del_f)
{
return htab_create_alloc (size, hash_f, eq_f, del_f, calloc, free);
}
Naturally the hash table must already exist. */
void
-htab_delete (htab)
- htab_t htab;
+htab_delete (htab_t htab)
{
size_t size = htab_size (htab);
PTR *entries = htab->entries;
if (htab->del_f)
for (i = size - 1; i >= 0; i--)
- if (entries[i] != EMPTY_ENTRY && entries[i] != DELETED_ENTRY)
+ if (entries[i] != HTAB_EMPTY_ENTRY && entries[i] != HTAB_DELETED_ENTRY)
(*htab->del_f) (entries[i]);
if (htab->free_f != NULL)
/* This function clears all entries in the given hash table. */
void
-htab_empty (htab)
- htab_t htab;
+htab_empty (htab_t htab)
{
size_t size = htab_size (htab);
PTR *entries = htab->entries;
if (htab->del_f)
for (i = size - 1; i >= 0; i--)
- if (entries[i] != EMPTY_ENTRY && entries[i] != DELETED_ENTRY)
+ if (entries[i] != HTAB_EMPTY_ENTRY && entries[i] != HTAB_DELETED_ENTRY)
(*htab->del_f) (entries[i]);
- memset (entries, 0, size * sizeof (PTR));
+ /* Instead of clearing megabyte, downsize the table. */
+ if (size > 1024*1024 / sizeof (PTR))
+ {
+ int nindex = higher_prime_index (1024 / sizeof (PTR));
+ int nsize = prime_tab[nindex].prime;
+
+ if (htab->free_f != NULL)
+ (*htab->free_f) (htab->entries);
+ else if (htab->free_with_arg_f != NULL)
+ (*htab->free_with_arg_f) (htab->alloc_arg, htab->entries);
+ if (htab->alloc_with_arg_f != NULL)
+ htab->entries = (PTR *) (*htab->alloc_with_arg_f) (htab->alloc_arg, nsize,
+ sizeof (PTR *));
+ else
+ htab->entries = (PTR *) (*htab->alloc_f) (nsize, sizeof (PTR *));
+ htab->size = nsize;
+ htab->size_prime_index = nindex;
+ }
+ else
+ memset (entries, 0, size * sizeof (PTR));
+ htab->n_deleted = 0;
+ htab->n_elements = 0;
}
/* Similar to htab_find_slot, but without several unwanted side effects:
HASH is the hash value for the element to be inserted. */
static PTR *
-find_empty_slot_for_expand (htab, hash)
- htab_t htab;
- hashval_t hash;
+find_empty_slot_for_expand (htab_t htab, hashval_t hash)
{
hashval_t index = htab_mod (hash, htab);
size_t size = htab_size (htab);
PTR *slot = htab->entries + index;
hashval_t hash2;
- if (*slot == EMPTY_ENTRY)
+ if (*slot == HTAB_EMPTY_ENTRY)
return slot;
- else if (*slot == DELETED_ENTRY)
+ else if (*slot == HTAB_DELETED_ENTRY)
abort ();
hash2 = htab_mod_m2 (hash, htab);
index -= size;
slot = htab->entries + index;
- if (*slot == EMPTY_ENTRY)
+ if (*slot == HTAB_EMPTY_ENTRY)
return slot;
- else if (*slot == DELETED_ENTRY)
+ else if (*slot == HTAB_DELETED_ENTRY)
abort ();
}
}
expanded. If all goes well, it will return a non-zero value. */
static int
-htab_expand (htab)
- htab_t htab;
+htab_expand (htab_t htab)
{
PTR *oentries;
PTR *olimit;
PTR *p;
PTR *nentries;
- size_t nsize;
+ size_t nsize, osize, elts;
+ unsigned int oindex, nindex;
oentries = htab->entries;
- olimit = oentries + htab->size;
+ oindex = htab->size_prime_index;
+ osize = htab->size;
+ olimit = oentries + osize;
+ elts = htab_elements (htab);
/* Resize only when table after removal of unused elements is either
too full or too empty. */
- if ((htab->n_elements - htab->n_deleted) * 2 > htab->size
- || ((htab->n_elements - htab->n_deleted) * 8 < htab->size
- && htab->size > 32))
- nsize = higher_prime_number ((htab->n_elements - htab->n_deleted) * 2);
+ if (elts * 2 > osize || (elts * 8 < osize && osize > 32))
+ {
+ nindex = higher_prime_index (elts * 2);
+ nsize = prime_tab[nindex].prime;
+ }
else
- nsize = htab->size;
+ {
+ nindex = oindex;
+ nsize = osize;
+ }
if (htab->alloc_with_arg_f != NULL)
nentries = (PTR *) (*htab->alloc_with_arg_f) (htab->alloc_arg, nsize,
return 0;
htab->entries = nentries;
htab->size = nsize;
-
+ htab->size_prime_index = nindex;
htab->n_elements -= htab->n_deleted;
htab->n_deleted = 0;
{
PTR x = *p;
- if (x != EMPTY_ENTRY && x != DELETED_ENTRY)
+ if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
{
PTR *q = find_empty_slot_for_expand (htab, (*htab->hash_f) (x));
element. It cannot be used to insert or delete an element. */
PTR
-htab_find_with_hash (htab, element, hash)
- htab_t htab;
- const PTR element;
- hashval_t hash;
+htab_find_with_hash (htab_t htab, const PTR element, hashval_t hash)
{
hashval_t index, hash2;
size_t size;
index = htab_mod (hash, htab);
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY
- || (entry != DELETED_ENTRY && (*htab->eq_f) (entry, element)))
+ if (entry == HTAB_EMPTY_ENTRY
+ || (entry != HTAB_DELETED_ENTRY && (*htab->eq_f) (entry, element)))
return entry;
hash2 = htab_mod_m2 (hash, htab);
index -= size;
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY
- || (entry != DELETED_ENTRY && (*htab->eq_f) (entry, element)))
+ if (entry == HTAB_EMPTY_ENTRY
+ || (entry != HTAB_DELETED_ENTRY && (*htab->eq_f) (entry, element)))
return entry;
}
}
element. */
PTR
-htab_find (htab, element)
- htab_t htab;
- const PTR element;
+htab_find (htab_t htab, const PTR element)
{
return htab_find_with_hash (htab, element, (*htab->hash_f) (element));
}
/* This function searches for a hash table slot containing an entry
equal to the given element. To delete an entry, call this with
- INSERT = 0, then call htab_clear_slot on the slot returned (possibly
- after doing some checks). To insert an entry, call this with
- INSERT = 1, then write the value you want into the returned slot.
- When inserting an entry, NULL may be returned if memory allocation
- fails. */
+ insert=NO_INSERT, then call htab_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. */
PTR *
-htab_find_slot_with_hash (htab, element, hash, insert)
- htab_t htab;
- const PTR element;
- hashval_t hash;
- enum insert_option insert;
+htab_find_slot_with_hash (htab_t htab, const PTR element,
+ hashval_t hash, enum insert_option insert)
{
PTR *first_deleted_slot;
hashval_t index, hash2;
first_deleted_slot = NULL;
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY)
+ if (entry == HTAB_EMPTY_ENTRY)
goto empty_entry;
- else if (entry == DELETED_ENTRY)
+ else if (entry == HTAB_DELETED_ENTRY)
first_deleted_slot = &htab->entries[index];
else if ((*htab->eq_f) (entry, element))
return &htab->entries[index];
index -= size;
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY)
+ if (entry == HTAB_EMPTY_ENTRY)
goto empty_entry;
- else if (entry == DELETED_ENTRY)
+ else if (entry == HTAB_DELETED_ENTRY)
{
if (!first_deleted_slot)
first_deleted_slot = &htab->entries[index];
if (first_deleted_slot)
{
htab->n_deleted--;
- *first_deleted_slot = EMPTY_ENTRY;
+ *first_deleted_slot = HTAB_EMPTY_ENTRY;
return first_deleted_slot;
}
element. */
PTR *
-htab_find_slot (htab, element, insert)
- htab_t htab;
- const PTR element;
- enum insert_option insert;
+htab_find_slot (htab_t htab, const PTR element, enum insert_option insert)
{
return htab_find_slot_with_hash (htab, element, (*htab->hash_f) (element),
insert);
element in the hash table, this function does nothing. */
void
-htab_remove_elt (htab, element)
- htab_t htab;
- PTR element;
+htab_remove_elt (htab_t htab, PTR element)
{
htab_remove_elt_with_hash (htab, element, (*htab->hash_f) (element));
}
function does nothing. */
void
-htab_remove_elt_with_hash (htab, element, hash)
- htab_t htab;
- PTR element;
- hashval_t hash;
+htab_remove_elt_with_hash (htab_t htab, PTR element, hashval_t hash)
{
PTR *slot;
slot = htab_find_slot_with_hash (htab, element, hash, NO_INSERT);
- if (*slot == EMPTY_ENTRY)
+ if (slot == NULL)
return;
if (htab->del_f)
(*htab->del_f) (*slot);
- *slot = DELETED_ENTRY;
+ *slot = HTAB_DELETED_ENTRY;
htab->n_deleted++;
}
again. */
void
-htab_clear_slot (htab, slot)
- htab_t htab;
- PTR *slot;
+htab_clear_slot (htab_t htab, PTR *slot)
{
if (slot < htab->entries || slot >= htab->entries + htab_size (htab)
- || *slot == EMPTY_ENTRY || *slot == DELETED_ENTRY)
+ || *slot == HTAB_EMPTY_ENTRY || *slot == HTAB_DELETED_ENTRY)
abort ();
if (htab->del_f)
(*htab->del_f) (*slot);
- *slot = DELETED_ENTRY;
+ *slot = HTAB_DELETED_ENTRY;
htab->n_deleted++;
}
argument. */
void
-htab_traverse_noresize (htab, callback, info)
- htab_t htab;
- htab_trav callback;
- PTR info;
+htab_traverse_noresize (htab_t htab, htab_trav callback, PTR info)
{
PTR *slot;
PTR *limit;
-
+
slot = htab->entries;
limit = slot + htab_size (htab);
{
PTR x = *slot;
- if (x != EMPTY_ENTRY && x != DELETED_ENTRY)
+ if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
if (!(*callback) (slot, info))
break;
}
too empty to improve effectivity of subsequent calls. */
void
-htab_traverse (htab, callback, info)
- htab_t htab;
- htab_trav callback;
- PTR info;
+htab_traverse (htab_t htab, htab_trav callback, PTR info)
{
- if (htab_elements (htab) * 8 < htab_size (htab))
+ size_t size = htab_size (htab);
+ if (htab_elements (htab) * 8 < size && size > 32)
htab_expand (htab);
htab_traverse_noresize (htab, callback, info);
hash table. */
double
-htab_collisions (htab)
- htab_t htab;
+htab_collisions (htab_t htab)
{
if (htab->searches == 0)
return 0.0;
function they just started using for Perl's hashes. */
hashval_t
-htab_hash_string (p)
- const PTR p;
+htab_hash_string (const PTR p)
{
const unsigned char *str = (const unsigned char *) p;
hashval_t r = 0;
--------------------------------------------------------------------
*/
-hashval_t iterative_hash (k_in, length, initval)
- const PTR k_in; /* the key */
- register size_t length; /* the length of the key */
- register hashval_t initval; /* the previous hash, or an arbitrary value */
+hashval_t
+iterative_hash (const PTR k_in /* the key */,
+ register size_t length /* the length of the key */,
+ register hashval_t initval /* the previous hash, or
+ an arbitrary value */)
{
register const unsigned char *k = (const unsigned char *)k_in;
register hashval_t a,b,c,len;
c += length;
switch(len) /* all the case statements fall through */
{
- case 11: c+=((hashval_t)k[10]<<24);
- case 10: c+=((hashval_t)k[9]<<16);
- case 9 : c+=((hashval_t)k[8]<<8);
+ case 11: c+=((hashval_t)k[10]<<24); /* fall through */
+ case 10: c+=((hashval_t)k[9]<<16); /* fall through */
+ case 9 : c+=((hashval_t)k[8]<<8); /* fall through */
/* the first byte of c is reserved for the length */
- case 8 : b+=((hashval_t)k[7]<<24);
- case 7 : b+=((hashval_t)k[6]<<16);
- case 6 : b+=((hashval_t)k[5]<<8);
- case 5 : b+=k[4];
- case 4 : a+=((hashval_t)k[3]<<24);
- case 3 : a+=((hashval_t)k[2]<<16);
- case 2 : a+=((hashval_t)k[1]<<8);
+ case 8 : b+=((hashval_t)k[7]<<24); /* fall through */
+ case 7 : b+=((hashval_t)k[6]<<16); /* fall through */
+ case 6 : b+=((hashval_t)k[5]<<8); /* fall through */
+ case 5 : b+=k[4]; /* fall through */
+ case 4 : a+=((hashval_t)k[3]<<24); /* fall through */
+ case 3 : a+=((hashval_t)k[2]<<16); /* fall through */
+ case 2 : a+=((hashval_t)k[1]<<8); /* fall through */
case 1 : a+=k[0];
/* case 0: nothing left to add */
}
/*-------------------------------------------- report the result */
return c;
}
+
+/* Returns a hash code for pointer P. Simplified version of evahash */
+
+static hashval_t
+hash_pointer (const PTR p)
+{
+ intptr_t v = (intptr_t) p;
+ unsigned a, b, c;
+
+ a = b = 0x9e3779b9;
+ a += v >> (sizeof (intptr_t) * CHAR_BIT / 2);
+ b += v & (((intptr_t) 1 << (sizeof (intptr_t) * CHAR_BIT / 2)) - 1);
+ c = 0x42135234;
+ mix (a, b, c);
+ return c;
+}