/* Hash tables.
|
/* Hash tables.
|
Copyright (C) 2000, 2001, 2003, 2004, 2008, 2009
|
Copyright (C) 2000, 2001, 2003, 2004, 2008, 2009
|
Free Software Foundation, Inc.
|
Free Software Foundation, Inc.
|
|
|
This program is free software; you can redistribute it and/or modify it
|
This program is free software; you can redistribute it and/or modify it
|
under the terms of the GNU General Public License as published by the
|
under the terms of the GNU General Public License as published by the
|
Free Software Foundation; either version 3, or (at your option) any
|
Free Software Foundation; either version 3, or (at your option) any
|
later version.
|
later version.
|
|
|
This program is distributed in the hope that it will be useful,
|
This program is distributed in the hope that it will be useful,
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
GNU General Public License for more details.
|
GNU General Public License for more details.
|
|
|
You should have received a copy of the GNU General Public License
|
You should have received a copy of the GNU General Public License
|
along with this program; see the file COPYING3. If not see
|
along with this program; see the file COPYING3. If not see
|
<http://www.gnu.org/licenses/>.
|
<http://www.gnu.org/licenses/>.
|
|
|
In other words, you are welcome to use, share and improve this program.
|
In other words, you are welcome to use, share and improve this program.
|
You are forbidden to forbid anyone else to use, share and improve
|
You are forbidden to forbid anyone else to use, share and improve
|
what you give them. Help stamp out software-hoarding! */
|
what you give them. Help stamp out software-hoarding! */
|
|
|
#include "config.h"
|
#include "config.h"
|
#include "system.h"
|
#include "system.h"
|
#include "symtab.h"
|
#include "symtab.h"
|
|
|
/* The code below is a specialization of Vladimir Makarov's expandable
|
/* The code below is a specialization of Vladimir Makarov's expandable
|
hash tables (see libiberty/hashtab.c). The abstraction penalty was
|
hash tables (see libiberty/hashtab.c). The abstraction penalty was
|
too high to continue using the generic form. This code knows
|
too high to continue using the generic form. This code knows
|
intrinsically how to calculate a hash value, and how to compare an
|
intrinsically how to calculate a hash value, and how to compare an
|
existing entry with a potential new one. */
|
existing entry with a potential new one. */
|
|
|
static unsigned int calc_hash (const unsigned char *, size_t);
|
static unsigned int calc_hash (const unsigned char *, size_t);
|
static void ht_expand (hash_table *);
|
static void ht_expand (hash_table *);
|
static double approx_sqrt (double);
|
static double approx_sqrt (double);
|
|
|
/* A deleted entry. */
|
/* A deleted entry. */
|
#define DELETED ((hashnode) -1)
|
#define DELETED ((hashnode) -1)
|
|
|
/* Calculate the hash of the string STR of length LEN. */
|
/* Calculate the hash of the string STR of length LEN. */
|
|
|
static unsigned int
|
static unsigned int
|
calc_hash (const unsigned char *str, size_t len)
|
calc_hash (const unsigned char *str, size_t len)
|
{
|
{
|
size_t n = len;
|
size_t n = len;
|
unsigned int r = 0;
|
unsigned int r = 0;
|
|
|
while (n--)
|
while (n--)
|
r = HT_HASHSTEP (r, *str++);
|
r = HT_HASHSTEP (r, *str++);
|
|
|
return HT_HASHFINISH (r, len);
|
return HT_HASHFINISH (r, len);
|
}
|
}
|
|
|
/* Initialize an identifier hashtable. */
|
/* Initialize an identifier hashtable. */
|
|
|
hash_table *
|
hash_table *
|
ht_create (unsigned int order)
|
ht_create (unsigned int order)
|
{
|
{
|
unsigned int nslots = 1 << order;
|
unsigned int nslots = 1 << order;
|
hash_table *table;
|
hash_table *table;
|
|
|
table = XCNEW (hash_table);
|
table = XCNEW (hash_table);
|
|
|
/* Strings need no alignment. */
|
/* Strings need no alignment. */
|
_obstack_begin (&table->stack, 0, 0,
|
_obstack_begin (&table->stack, 0, 0,
|
(void *(*) (long)) xmalloc,
|
(void *(*) (long)) xmalloc,
|
(void (*) (void *)) free);
|
(void (*) (void *)) free);
|
|
|
obstack_alignment_mask (&table->stack) = 0;
|
obstack_alignment_mask (&table->stack) = 0;
|
|
|
table->entries = XCNEWVEC (hashnode, nslots);
|
table->entries = XCNEWVEC (hashnode, nslots);
|
table->entries_owned = true;
|
table->entries_owned = true;
|
table->nslots = nslots;
|
table->nslots = nslots;
|
return table;
|
return table;
|
}
|
}
|
|
|
/* Frees all memory associated with a hash table. */
|
/* Frees all memory associated with a hash table. */
|
|
|
void
|
void
|
ht_destroy (hash_table *table)
|
ht_destroy (hash_table *table)
|
{
|
{
|
obstack_free (&table->stack, NULL);
|
obstack_free (&table->stack, NULL);
|
if (table->entries_owned)
|
if (table->entries_owned)
|
free (table->entries);
|
free (table->entries);
|
free (table);
|
free (table);
|
}
|
}
|
|
|
/* Returns the hash entry for the a STR of length LEN. If that string
|
/* Returns the hash entry for the a STR of length LEN. If that string
|
already exists in the table, returns the existing entry. If the
|
already exists in the table, returns the existing entry. If the
|
identifier hasn't been seen before, and INSERT is CPP_NO_INSERT,
|
identifier hasn't been seen before, and INSERT is CPP_NO_INSERT,
|
returns NULL. Otherwise insert and returns a new entry. A new
|
returns NULL. Otherwise insert and returns a new entry. A new
|
string is allocated. */
|
string is allocated. */
|
hashnode
|
hashnode
|
ht_lookup (hash_table *table, const unsigned char *str, size_t len,
|
ht_lookup (hash_table *table, const unsigned char *str, size_t len,
|
enum ht_lookup_option insert)
|
enum ht_lookup_option insert)
|
{
|
{
|
return ht_lookup_with_hash (table, str, len, calc_hash (str, len),
|
return ht_lookup_with_hash (table, str, len, calc_hash (str, len),
|
insert);
|
insert);
|
}
|
}
|
|
|
hashnode
|
hashnode
|
ht_lookup_with_hash (hash_table *table, const unsigned char *str,
|
ht_lookup_with_hash (hash_table *table, const unsigned char *str,
|
size_t len, unsigned int hash,
|
size_t len, unsigned int hash,
|
enum ht_lookup_option insert)
|
enum ht_lookup_option insert)
|
{
|
{
|
unsigned int hash2;
|
unsigned int hash2;
|
unsigned int index;
|
unsigned int index;
|
unsigned int deleted_index = table->nslots;
|
unsigned int deleted_index = table->nslots;
|
size_t sizemask;
|
size_t sizemask;
|
hashnode node;
|
hashnode node;
|
|
|
sizemask = table->nslots - 1;
|
sizemask = table->nslots - 1;
|
index = hash & sizemask;
|
index = hash & sizemask;
|
table->searches++;
|
table->searches++;
|
|
|
node = table->entries[index];
|
node = table->entries[index];
|
|
|
if (node != NULL)
|
if (node != NULL)
|
{
|
{
|
if (node == DELETED)
|
if (node == DELETED)
|
deleted_index = index;
|
deleted_index = index;
|
else if (node->hash_value == hash
|
else if (node->hash_value == hash
|
&& HT_LEN (node) == (unsigned int) len
|
&& HT_LEN (node) == (unsigned int) len
|
&& !memcmp (HT_STR (node), str, len))
|
&& !memcmp (HT_STR (node), str, len))
|
return node;
|
return node;
|
|
|
/* hash2 must be odd, so we're guaranteed to visit every possible
|
/* hash2 must be odd, so we're guaranteed to visit every possible
|
location in the table during rehashing. */
|
location in the table during rehashing. */
|
hash2 = ((hash * 17) & sizemask) | 1;
|
hash2 = ((hash * 17) & sizemask) | 1;
|
|
|
for (;;)
|
for (;;)
|
{
|
{
|
table->collisions++;
|
table->collisions++;
|
index = (index + hash2) & sizemask;
|
index = (index + hash2) & sizemask;
|
node = table->entries[index];
|
node = table->entries[index];
|
if (node == NULL)
|
if (node == NULL)
|
break;
|
break;
|
|
|
if (node == DELETED)
|
if (node == DELETED)
|
{
|
{
|
if (deleted_index != table->nslots)
|
if (deleted_index != table->nslots)
|
deleted_index = index;
|
deleted_index = index;
|
}
|
}
|
else if (node->hash_value == hash
|
else if (node->hash_value == hash
|
&& HT_LEN (node) == (unsigned int) len
|
&& HT_LEN (node) == (unsigned int) len
|
&& !memcmp (HT_STR (node), str, len))
|
&& !memcmp (HT_STR (node), str, len))
|
return node;
|
return node;
|
}
|
}
|
}
|
}
|
|
|
if (insert == HT_NO_INSERT)
|
if (insert == HT_NO_INSERT)
|
return NULL;
|
return NULL;
|
|
|
/* We prefer to overwrite the first deleted slot we saw. */
|
/* We prefer to overwrite the first deleted slot we saw. */
|
if (deleted_index != table->nslots)
|
if (deleted_index != table->nslots)
|
index = deleted_index;
|
index = deleted_index;
|
|
|
node = (*table->alloc_node) (table);
|
node = (*table->alloc_node) (table);
|
table->entries[index] = node;
|
table->entries[index] = node;
|
|
|
HT_LEN (node) = (unsigned int) len;
|
HT_LEN (node) = (unsigned int) len;
|
node->hash_value = hash;
|
node->hash_value = hash;
|
|
|
if (table->alloc_subobject)
|
if (table->alloc_subobject)
|
{
|
{
|
char *chars = (char *) table->alloc_subobject (len + 1);
|
char *chars = (char *) table->alloc_subobject (len + 1);
|
memcpy (chars, str, len);
|
memcpy (chars, str, len);
|
chars[len] = '\0';
|
chars[len] = '\0';
|
HT_STR (node) = (const unsigned char *) chars;
|
HT_STR (node) = (const unsigned char *) chars;
|
}
|
}
|
else
|
else
|
HT_STR (node) = (const unsigned char *) obstack_copy0 (&table->stack,
|
HT_STR (node) = (const unsigned char *) obstack_copy0 (&table->stack,
|
str, len);
|
str, len);
|
|
|
if (++table->nelements * 4 >= table->nslots * 3)
|
if (++table->nelements * 4 >= table->nslots * 3)
|
/* Must expand the string table. */
|
/* Must expand the string table. */
|
ht_expand (table);
|
ht_expand (table);
|
|
|
return node;
|
return node;
|
}
|
}
|
|
|
/* Double the size of a hash table, re-hashing existing entries. */
|
/* Double the size of a hash table, re-hashing existing entries. */
|
|
|
static void
|
static void
|
ht_expand (hash_table *table)
|
ht_expand (hash_table *table)
|
{
|
{
|
hashnode *nentries, *p, *limit;
|
hashnode *nentries, *p, *limit;
|
unsigned int size, sizemask;
|
unsigned int size, sizemask;
|
|
|
size = table->nslots * 2;
|
size = table->nslots * 2;
|
nentries = XCNEWVEC (hashnode, size);
|
nentries = XCNEWVEC (hashnode, size);
|
sizemask = size - 1;
|
sizemask = size - 1;
|
|
|
p = table->entries;
|
p = table->entries;
|
limit = p + table->nslots;
|
limit = p + table->nslots;
|
do
|
do
|
if (*p && *p != DELETED)
|
if (*p && *p != DELETED)
|
{
|
{
|
unsigned int index, hash, hash2;
|
unsigned int index, hash, hash2;
|
|
|
hash = (*p)->hash_value;
|
hash = (*p)->hash_value;
|
index = hash & sizemask;
|
index = hash & sizemask;
|
|
|
if (nentries[index])
|
if (nentries[index])
|
{
|
{
|
hash2 = ((hash * 17) & sizemask) | 1;
|
hash2 = ((hash * 17) & sizemask) | 1;
|
do
|
do
|
{
|
{
|
index = (index + hash2) & sizemask;
|
index = (index + hash2) & sizemask;
|
}
|
}
|
while (nentries[index]);
|
while (nentries[index]);
|
}
|
}
|
nentries[index] = *p;
|
nentries[index] = *p;
|
}
|
}
|
while (++p < limit);
|
while (++p < limit);
|
|
|
if (table->entries_owned)
|
if (table->entries_owned)
|
free (table->entries);
|
free (table->entries);
|
table->entries_owned = true;
|
table->entries_owned = true;
|
table->entries = nentries;
|
table->entries = nentries;
|
table->nslots = size;
|
table->nslots = size;
|
}
|
}
|
|
|
/* For all nodes in TABLE, callback CB with parameters TABLE->PFILE,
|
/* For all nodes in TABLE, callback CB with parameters TABLE->PFILE,
|
the node, and V. */
|
the node, and V. */
|
void
|
void
|
ht_forall (hash_table *table, ht_cb cb, const void *v)
|
ht_forall (hash_table *table, ht_cb cb, const void *v)
|
{
|
{
|
hashnode *p, *limit;
|
hashnode *p, *limit;
|
|
|
p = table->entries;
|
p = table->entries;
|
limit = p + table->nslots;
|
limit = p + table->nslots;
|
do
|
do
|
if (*p && *p != DELETED)
|
if (*p && *p != DELETED)
|
{
|
{
|
if ((*cb) (table->pfile, *p, v) == 0)
|
if ((*cb) (table->pfile, *p, v) == 0)
|
break;
|
break;
|
}
|
}
|
while (++p < limit);
|
while (++p < limit);
|
}
|
}
|
|
|
/* Like ht_forall, but a nonzero return from the callback means that
|
/* Like ht_forall, but a nonzero return from the callback means that
|
the entry should be removed from the table. */
|
the entry should be removed from the table. */
|
void
|
void
|
ht_purge (hash_table *table, ht_cb cb, const void *v)
|
ht_purge (hash_table *table, ht_cb cb, const void *v)
|
{
|
{
|
hashnode *p, *limit;
|
hashnode *p, *limit;
|
|
|
p = table->entries;
|
p = table->entries;
|
limit = p + table->nslots;
|
limit = p + table->nslots;
|
do
|
do
|
if (*p && *p != DELETED)
|
if (*p && *p != DELETED)
|
{
|
{
|
if ((*cb) (table->pfile, *p, v))
|
if ((*cb) (table->pfile, *p, v))
|
*p = DELETED;
|
*p = DELETED;
|
}
|
}
|
while (++p < limit);
|
while (++p < limit);
|
}
|
}
|
|
|
/* Restore the hash table. */
|
/* Restore the hash table. */
|
void
|
void
|
ht_load (hash_table *ht, hashnode *entries,
|
ht_load (hash_table *ht, hashnode *entries,
|
unsigned int nslots, unsigned int nelements,
|
unsigned int nslots, unsigned int nelements,
|
bool own)
|
bool own)
|
{
|
{
|
if (ht->entries_owned)
|
if (ht->entries_owned)
|
free (ht->entries);
|
free (ht->entries);
|
ht->entries = entries;
|
ht->entries = entries;
|
ht->nslots = nslots;
|
ht->nslots = nslots;
|
ht->nelements = nelements;
|
ht->nelements = nelements;
|
ht->entries_owned = own;
|
ht->entries_owned = own;
|
}
|
}
|
|
|
/* Dump allocation statistics to stderr. */
|
/* Dump allocation statistics to stderr. */
|
|
|
void
|
void
|
ht_dump_statistics (hash_table *table)
|
ht_dump_statistics (hash_table *table)
|
{
|
{
|
size_t nelts, nids, overhead, headers;
|
size_t nelts, nids, overhead, headers;
|
size_t total_bytes, longest, deleted = 0;
|
size_t total_bytes, longest, deleted = 0;
|
double sum_of_squares, exp_len, exp_len2, exp2_len;
|
double sum_of_squares, exp_len, exp_len2, exp2_len;
|
hashnode *p, *limit;
|
hashnode *p, *limit;
|
|
|
#define SCALE(x) ((unsigned long) ((x) < 1024*10 \
|
#define SCALE(x) ((unsigned long) ((x) < 1024*10 \
|
? (x) \
|
? (x) \
|
: ((x) < 1024*1024*10 \
|
: ((x) < 1024*1024*10 \
|
? (x) / 1024 \
|
? (x) / 1024 \
|
: (x) / (1024*1024))))
|
: (x) / (1024*1024))))
|
#define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
|
#define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
|
|
|
total_bytes = longest = sum_of_squares = nids = 0;
|
total_bytes = longest = sum_of_squares = nids = 0;
|
p = table->entries;
|
p = table->entries;
|
limit = p + table->nslots;
|
limit = p + table->nslots;
|
do
|
do
|
if (*p == DELETED)
|
if (*p == DELETED)
|
++deleted;
|
++deleted;
|
else if (*p)
|
else if (*p)
|
{
|
{
|
size_t n = HT_LEN (*p);
|
size_t n = HT_LEN (*p);
|
|
|
total_bytes += n;
|
total_bytes += n;
|
sum_of_squares += (double) n * n;
|
sum_of_squares += (double) n * n;
|
if (n > longest)
|
if (n > longest)
|
longest = n;
|
longest = n;
|
nids++;
|
nids++;
|
}
|
}
|
while (++p < limit);
|
while (++p < limit);
|
|
|
nelts = table->nelements;
|
nelts = table->nelements;
|
overhead = obstack_memory_used (&table->stack) - total_bytes;
|
overhead = obstack_memory_used (&table->stack) - total_bytes;
|
headers = table->nslots * sizeof (hashnode);
|
headers = table->nslots * sizeof (hashnode);
|
|
|
fprintf (stderr, "\nString pool\nentries\t\t%lu\n",
|
fprintf (stderr, "\nString pool\nentries\t\t%lu\n",
|
(unsigned long) nelts);
|
(unsigned long) nelts);
|
fprintf (stderr, "identifiers\t%lu (%.2f%%)\n",
|
fprintf (stderr, "identifiers\t%lu (%.2f%%)\n",
|
(unsigned long) nids, nids * 100.0 / nelts);
|
(unsigned long) nids, nids * 100.0 / nelts);
|
fprintf (stderr, "slots\t\t%lu\n",
|
fprintf (stderr, "slots\t\t%lu\n",
|
(unsigned long) table->nslots);
|
(unsigned long) table->nslots);
|
fprintf (stderr, "deleted\t\t%lu\n",
|
fprintf (stderr, "deleted\t\t%lu\n",
|
(unsigned long) deleted);
|
(unsigned long) deleted);
|
fprintf (stderr, "bytes\t\t%lu%c (%lu%c overhead)\n",
|
fprintf (stderr, "bytes\t\t%lu%c (%lu%c overhead)\n",
|
SCALE (total_bytes), LABEL (total_bytes),
|
SCALE (total_bytes), LABEL (total_bytes),
|
SCALE (overhead), LABEL (overhead));
|
SCALE (overhead), LABEL (overhead));
|
fprintf (stderr, "table size\t%lu%c\n",
|
fprintf (stderr, "table size\t%lu%c\n",
|
SCALE (headers), LABEL (headers));
|
SCALE (headers), LABEL (headers));
|
|
|
exp_len = (double)total_bytes / (double)nelts;
|
exp_len = (double)total_bytes / (double)nelts;
|
exp2_len = exp_len * exp_len;
|
exp2_len = exp_len * exp_len;
|
exp_len2 = (double) sum_of_squares / (double) nelts;
|
exp_len2 = (double) sum_of_squares / (double) nelts;
|
|
|
fprintf (stderr, "coll/search\t%.4f\n",
|
fprintf (stderr, "coll/search\t%.4f\n",
|
(double) table->collisions / (double) table->searches);
|
(double) table->collisions / (double) table->searches);
|
fprintf (stderr, "ins/search\t%.4f\n",
|
fprintf (stderr, "ins/search\t%.4f\n",
|
(double) nelts / (double) table->searches);
|
(double) nelts / (double) table->searches);
|
fprintf (stderr, "avg. entry\t%.2f bytes (+/- %.2f)\n",
|
fprintf (stderr, "avg. entry\t%.2f bytes (+/- %.2f)\n",
|
exp_len, approx_sqrt (exp_len2 - exp2_len));
|
exp_len, approx_sqrt (exp_len2 - exp2_len));
|
fprintf (stderr, "longest entry\t%lu\n",
|
fprintf (stderr, "longest entry\t%lu\n",
|
(unsigned long) longest);
|
(unsigned long) longest);
|
#undef SCALE
|
#undef SCALE
|
#undef LABEL
|
#undef LABEL
|
}
|
}
|
|
|
/* Return the approximate positive square root of a number N. This is for
|
/* Return the approximate positive square root of a number N. This is for
|
statistical reports, not code generation. */
|
statistical reports, not code generation. */
|
static double
|
static double
|
approx_sqrt (double x)
|
approx_sqrt (double x)
|
{
|
{
|
double s, d;
|
double s, d;
|
|
|
if (x < 0)
|
if (x < 0)
|
abort ();
|
abort ();
|
if (x == 0)
|
if (x == 0)
|
return 0;
|
return 0;
|
|
|
s = x;
|
s = x;
|
do
|
do
|
{
|
{
|
d = (s * s - x) / (2 * s);
|
d = (s * s - x) / (2 * s);
|
s -= d;
|
s -= d;
|
}
|
}
|
while (d > .0001);
|
while (d > .0001);
|
return s;
|
return s;
|
}
|
}
|
|
|
