PR 3532

[deliverable/binutils-gdb.git] / bfd / hash.c

diff --git a/bfd/hash.c b/bfd/hash.c
index ce9ba5c6297fb436274b828939bde37f27dbc7c2..1157980a8f8aa06f591cabed7dc270a47574c736 100644 (file)
--- a/bfd/hash.c
+++ b/bfd/hash.c
@@ -299,6 +299,58 @@ SUBSUBSECTION
 
 /* The default number of entries to use when creating a hash table.  */
 #define DEFAULT_SIZE 4051
+
+/* The following function returns a nearest prime number which is
+   greater than N, and near a power of two.  Copied from libiberty.
+   Returns zero for ridiculously large N to signify an error.  */
+
+static unsigned long
+higher_prime_number (unsigned long n)
+{
+  /* These are primes that are near, but slightly smaller than, a
+     power of two.  */
+  static const unsigned long primes[] = {
+    (unsigned long) 127,
+    (unsigned long) 2039,
+    (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])];
+
+  while (low != high)
+    {
+      const unsigned long *mid = low + (high - low) / 2;
+      if (n >= *mid)
+       low = mid + 1;
+      else
+       high = mid;
+    }
+
+  if (n >= *low)
+    return 0;
+
+  return *low;
+}
+
 static size_t bfd_default_hash_table_size = DEFAULT_SIZE;
 
 /* Create a new hash table, given a number of entries.  */
@@ -330,6 +382,8 @@ bfd_hash_table_init_n (struct bfd_hash_table *table,
   memset ((void *) table->table, 0, alloc);
   table->size = size;
   table->entsize = entsize;
+  table->count = 0;
+  table->frozen = 0;
   table->newfunc = newfunc;
   return TRUE;
 }
@@ -416,6 +470,45 @@ bfd_hash_lookup (struct bfd_hash_table *table,
   hashp->hash = hash;
   hashp->next = table->table[index];
   table->table[index] = hashp;
+  table->count++;
+
+  if (!table->frozen && table->count > table->size * 3 / 4)
+    {
+      unsigned long newsize = higher_prime_number (table->size);
+      struct bfd_hash_entry **newtable;
+      unsigned int hi;
+      unsigned long alloc = newsize * sizeof (struct bfd_hash_entry *);
+
+      /* If we can't find a higher prime, or we can't possibly alloc
+        that much memory, don't try to grow the table.  */
+      if (newsize == 0 || alloc / sizeof (struct bfd_hash_entry *) != newsize)
+       {
+         table->frozen = 1;
+         return hashp;
+       }
+
+      newtable = ((struct bfd_hash_entry **)
+                 objalloc_alloc ((struct objalloc *) table->memory, alloc));
+      memset ((PTR) newtable, 0, alloc);
+
+      for (hi = 0; hi < table->size; hi ++)
+       while (table->table[hi])
+         {
+           struct bfd_hash_entry *chain = table->table[hi];
+           struct bfd_hash_entry *chain_end = chain;
+           int index;
+
+           while (chain_end->next && chain_end->next->hash == chain->hash)
+             chain_end = chain_end->next;
+
+           table->table[hi] = chain_end->next;
+           index = chain->hash % newsize;
+           chain_end->next = newtable[index];
+           newtable[index] = chain;
+         }
+      table->table = newtable;
+      table->size = newsize;
+    }
 
   return hashp;
 }
@@ -480,14 +573,17 @@ bfd_hash_traverse (struct bfd_hash_table *table,
 {
   unsigned int i;
 
+  table->frozen = 1;
   for (i = 0; i < table->size; i++)
     {
       struct bfd_hash_entry *p;
 
       for (p = table->table[i]; p != NULL; p = p->next)
        if (! (*func) (p, info))
-         return;
+         goto out;
     }
+ out:
+  table->frozen = 0;
 }
 \f
 void