// stringpool.cc -- a string pool for gold
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
template<typename Stringpool_char>
Stringpool_template<Stringpool_char>::Stringpool_template()
- : string_set_(), strings_(), strtab_size_(0), next_index_(1),
- next_uncopied_key_(-1), zero_null_(true)
+ : string_set_(), key_to_offset_(), strings_(), strtab_size_(0),
+ zero_null_(true)
{
}
++p)
delete[] reinterpret_cast<char*>(*p);
this->strings_.clear();
+ this->key_to_offset_.clear();
this->string_set_.clear();
}
void
Stringpool_template<Stringpool_char>::reserve(unsigned int n)
{
+ this->key_to_offset_.reserve(n);
+
#if defined(HAVE_TR1_UNORDERED_MAP)
// rehash() implementation is broken in gcc 4.0.3's stl
//this->string_set_.rehash(this->string_set_.size() + n);
{
return (h1.hash_code == h2.hash_code
&& h1.length == h2.length
- && memcmp(h1.string, h2.string,
- h1.length * sizeof(Stringpool_char)) == 0);
+ && (h1.string == h2.string
+ || memcmp(h1.string, h2.string,
+ h1.length * sizeof(Stringpool_char)) == 0));
}
// Hash function. The length is in characters, not bytes.
Stringpool_template<Stringpool_char>::string_hash(const Stringpool_char* s,
size_t length)
{
- // Fowler/Noll/Vo (FNV) hash (type FNV-1a).
+ // This is the hash function used by the dynamic linker for
+ // DT_GNU_HASH entries. I compared this to a Fowler/Noll/Vo hash
+ // for a C++ program with 385,775 global symbols. This hash
+ // function was very slightly worse. However, it is much faster to
+ // compute. Overall wall clock time was a win.
const unsigned char* p = reinterpret_cast<const unsigned char*>(s);
- if (sizeof(size_t) > 4)
- {
- size_t result = static_cast<size_t>(14695981039346656037ULL);
- for (size_t i = 0; i < length * sizeof(Stringpool_char); ++i)
- {
- result ^= static_cast<size_t>(*p++);
- result *= 1099511628211ULL;
- }
- return result;
- }
- else
- {
- size_t result = 2166136261UL;
- for (size_t i = 0; i < length * sizeof(Stringpool_char); ++i)
- {
- result ^= static_cast<size_t>(*p++);
- result *= 16777619UL;
- }
- return result;
- }
+ size_t h = 5381;
+ for (size_t i = 0; i < length * sizeof(Stringpool_char); ++i)
+ h = h * 33 + *p++;
+ return h;
}
// Add the string S to the list of canonical strings. Return a
template<typename Stringpool_char>
const Stringpool_char*
Stringpool_template<Stringpool_char>::add_string(const Stringpool_char* s,
- size_t len,
- Key* pkey)
+ size_t len)
{
// We are in trouble if we've already computed the string offsets.
gold_assert(this->strtab_size_ == 0);
memset(ret + len - sizeof(Stringpool_char), 0,
sizeof(Stringpool_char));
- if (pkey != NULL)
- *pkey = psd->index * key_mult + psd->len;
-
psd->len += len;
return reinterpret_cast<const Stringpool_char*>(ret);
memset(psd->data + len - sizeof(Stringpool_char), 0,
sizeof(Stringpool_char));
psd->len = len;
- psd->index = this->next_index_;
- ++this->next_index_;
-
- if (pkey != NULL)
- {
- *pkey = psd->index * key_mult;
- // Ensure there was no overflow.
- gold_assert(*pkey / key_mult == psd->index);
- }
if (front)
this->strings_.push_front(psd);
const Stringpool_char*
Stringpool_template<Stringpool_char>::add(const Stringpool_char* s, bool copy,
Key* pkey)
+{
+ return this->add_with_length(s, string_length(s), copy, pkey);
+}
+
+template<typename Stringpool_char>
+const Stringpool_char*
+Stringpool_template<Stringpool_char>::add_with_length(const Stringpool_char* s,
+ size_t length,
+ bool copy,
+ Key* pkey)
{
typedef std::pair<typename String_set_type::iterator, bool> Insert_type;
+ // We add 1 so that 0 is always invalid.
+ const Key k = this->key_to_offset_.size() + 1;
+
if (!copy)
{
// When we don't need to copy the string, we can call insert
// directly.
- const Key k = this->next_uncopied_key_;
- const section_offset_type ozero = 0;
- std::pair<Hashkey, Hashval> element(Hashkey(s),
- std::make_pair(k, ozero));
+ std::pair<Hashkey, Hashval> element(Hashkey(s, length), k);
Insert_type ins = this->string_set_.insert(element);
{
// We just added the string. The key value has now been
// used.
- --this->next_uncopied_key_;
+ this->key_to_offset_.push_back(0);
}
else
{
- gold_assert(k != p->second.first);
+ gold_assert(k != p->second);
}
if (pkey != NULL)
- *pkey = p->second.first;
+ *pkey = p->second;
return p->first.string;
}
- return this->add_prefix(s, string_length(s), pkey);
-}
-
-// Add a prefix of a string to a string pool.
-
-template<typename Stringpool_char>
-const Stringpool_char*
-Stringpool_template<Stringpool_char>::add_prefix(const Stringpool_char* s,
- size_t len,
- Key* pkey)
-{
- // When adding an entry, this will look it up twice in the hash
+ // When we have to copy the string, we look it up twice in the hash
// table. The problem is that we can't insert S before we
// canonicalize it by copying it into the canonical list. The hash
- // code will only be computed once, so this isn't all that
- // expensive.
+ // code will only be computed once.
- Hashkey hk(s, len);
+ Hashkey hk(s, length);
typename String_set_type::const_iterator p = this->string_set_.find(hk);
if (p != this->string_set_.end())
{
if (pkey != NULL)
- *pkey = p->second.first;
+ *pkey = p->second;
return p->first.string;
}
- Key k;
- hk.string = this->add_string(s, len, &k);
+ this->key_to_offset_.push_back(0);
+
+ hk.string = this->add_string(s, length);
// The contents of the string stay the same, so we don't need to
// adjust hk.hash_code or hk.length.
- const section_offset_type ozero = 0;
- std::pair<Hashkey, Hashval> element(hk, std::make_pair(k, ozero));
+ std::pair<Hashkey, Hashval> element(hk, k);
- typedef std::pair<typename String_set_type::iterator, bool> Insert_type;
Insert_type ins = this->string_set_.insert(element);
gold_assert(ins.second);
return NULL;
if (pkey != NULL)
- *pkey = p->second.first;
+ *pkey = p->second;
return p->first.string;
}
// the strtab size, and gives a relatively small benefit (it's
// typically rare for a symbol to be a suffix of another), we only
// take the time to sort when the user asks for heavy optimization.
- if (parameters->optimization_level() < 2)
+ if (parameters->options().optimize() < 2)
{
for (typename String_set_type::iterator curr = this->string_set_.begin();
curr != this->string_set_.end();
curr++)
{
+ section_offset_type* poff = &this->key_to_offset_[curr->second - 1];
if (this->zero_null_ && curr->first.string[0] == 0)
- curr->second.second = 0;
+ *poff = 0;
else
{
- curr->second.second = offset;
+ *poff = offset;
offset += (curr->first.length + 1) * charsize;
}
}
std::sort(v.begin(), v.end(), Stringpool_sort_comparison());
+ section_offset_type last_offset = -1;
for (typename std::vector<Stringpool_sort_info>::iterator last = v.end(),
curr = v.begin();
curr != v.end();
last = curr++)
{
+ section_offset_type this_offset;
if (this->zero_null_ && (*curr)->first.string[0] == 0)
- (*curr)->second.second = 0;
+ this_offset = 0;
else if (last != v.end()
&& is_suffix((*curr)->first.string,
(*curr)->first.length,
(*last)->first.string,
(*last)->first.length))
- (*curr)->second.second = ((*last)->second.second
- + (((*last)->first.length
- - (*curr)->first.length)
- * charsize));
+ this_offset = (last_offset
+ + (((*last)->first.length - (*curr)->first.length)
+ * charsize));
else
{
- (*curr)->second.second = offset;
+ this_offset = offset;
offset += ((*curr)->first.length + 1) * charsize;
}
+ this->key_to_offset_[(*curr)->second - 1] = this_offset;
+ last_offset = this_offset;
}
}
section_offset_type
Stringpool_template<Stringpool_char>::get_offset(const Stringpool_char* s)
const
+{
+ return this->get_offset_with_length(s, string_length(s));
+}
+
+template<typename Stringpool_char>
+section_offset_type
+Stringpool_template<Stringpool_char>::get_offset_with_length(
+ const Stringpool_char* s,
+ size_t length) const
{
gold_assert(this->strtab_size_ != 0);
- typename String_set_type::const_iterator p = this->string_set_.find(s);
+ Hashkey hk(s, length);
+ typename String_set_type::const_iterator p = this->string_set_.find(hk);
if (p != this->string_set_.end())
- return p->second.second;
+ return this->key_to_offset_[p->second - 1];
gold_unreachable();
}
++p)
{
const int len = (p->first.length + 1) * sizeof(Stringpool_char);
- gold_assert(static_cast<section_size_type>(p->second.second) + len
+ const section_offset_type offset = this->key_to_offset_[p->second - 1];
+ gold_assert(static_cast<section_size_type>(offset) + len
<= this->strtab_size_);
- memcpy(buffer + p->second.second, p->first.string, len);
+ memcpy(buffer + offset, p->first.string, len);
}
}