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[Patch]: Corrected patch for stl_tree.h to improve performance andmemory usage
- From: Gawain Bolton <gp dot bolton at computer dot org>
- To: "libstdc++ at gcc dot gnu dot org" <libstdc++ at gcc dot gnu dot org>
- Date: Wed, 05 Mar 2003 23:21:59 +0100
- Subject: [Patch]: Corrected patch for stl_tree.h to improve performance andmemory usage
Ok, here I go again. Please find attached a patch for stl_tree.h to
improve performance and memory usage. This patch differs from the
previous one (http://gcc.gnu.org/ml/libstdc++/2003-02/msg00398.html) in
that all compile errors have (hopefully) been fixed - the joys of
template classes! - as well as the implementation of the swap()
function which was seriously broken.
The swap() function is more complicated in order to deal with the
complications of having a non-pointer header data member. However, I
believe it satisfies the standard's requirements that it:
1. has constant complexity
2. will not throw an exception
3. does not invalidate any references, pointers, or iterators.
Some performance numbers were posted previously. This can be found here:
http://gcc.gnu.org/ml/libstdc++/2003-03/msg00000.html
Once again, all and any feedback appreciated.
Cheers,
Gawain
Index: stl_tree.h
===================================================================
RCS file: /cvsroot/gcc/gcc/libstdc++-v3/include/bits/stl_tree.h,v
retrieving revision 1.19
diff -u -r1.19 stl_tree.h
--- stl_tree.h 16 Jan 2003 20:30:24 -0000 1.19
+++ stl_tree.h 5 Mar 2003 22:01:40 -0000
@@ -192,7 +192,7 @@
typedef _Rb_tree_node<_Val>* _Link_type;
_Rb_tree_iterator() {}
- _Rb_tree_iterator(_Link_type __x) { _M_node = __x; }
+ _Rb_tree_iterator(_Rb_tree_node_base * __x) { _M_node = __x; }
_Rb_tree_iterator(const iterator& __it) { _M_node = __it._M_node; }
reference
@@ -528,13 +528,13 @@
get_allocator() const { return _M_node_allocator; }
_Rb_tree_alloc_base(const allocator_type& __a)
- : _M_node_allocator(__a), _M_header(0) {}
+ : _M_node_allocator(__a) {}
protected:
typename _Alloc_traits<_Rb_tree_node<_Tp>, _Alloc>::allocator_type
_M_node_allocator;
- _Rb_tree_node<_Tp>* _M_header;
+ _Rb_tree_node_base _M_header;
_Rb_tree_node<_Tp>*
_M_get_node() { return _M_node_allocator.allocate(1); }
@@ -552,10 +552,10 @@
typedef typename _Alloc_traits<_Tp, _Alloc>::allocator_type allocator_type;
allocator_type get_allocator() const { return allocator_type(); }
- _Rb_tree_alloc_base(const allocator_type&) : _M_header(0) {}
+ _Rb_tree_alloc_base(const allocator_type&) {}
protected:
- _Rb_tree_node<_Tp>* _M_header;
+ _Rb_tree_node_base _M_header;
typedef typename _Alloc_traits<_Rb_tree_node<_Tp>, _Alloc>::_Alloc_type
_Alloc_type;
@@ -576,8 +576,7 @@
typedef typename _Base::allocator_type allocator_type;
_Rb_tree_base(const allocator_type& __a)
- : _Base(__a) { this->_M_header = _M_get_node(); }
- ~_Rb_tree_base() { _M_put_node(this->_M_header); }
+ : _Base(__a) {}
};
@@ -645,14 +644,17 @@
_Compare _M_key_compare;
_Link_type&
- _M_root() const { return (_Link_type&) this->_M_header->_M_parent; }
+ _M_root() const { return (_Link_type&) this->_M_header._M_parent; }
_Link_type&
- _M_leftmost() const { return (_Link_type&) this->_M_header->_M_left; }
+ _M_leftmost() const { return (_Link_type&) this->_M_header._M_left; }
_Link_type&
- _M_rightmost() const { return (_Link_type&) this->_M_header->_M_right; }
+ _M_rightmost() const { return (_Link_type&) this->_M_header._M_right; }
+ _Link_type
+ _M_end() const { return (_Link_type) &this->_M_header; }
+
static _Link_type&
_S_left(_Link_type __x) { return (_Link_type&)(__x->_M_left); }
@@ -668,9 +670,6 @@
static const _Key&
_S_key(_Link_type __x) { return _KeyOfValue()(_S_value(__x)); }
- static _Rb_tree_color&
- _S_color(_Link_type __x) { return __x->_M_color; }
-
static _Link_type&
_S_left(_Base_ptr __x) { return (_Link_type&)(__x->_M_left); }
@@ -687,7 +686,7 @@
_S_key(_Base_ptr __x) { return _KeyOfValue()(_S_value(_Link_type(__x)));}
static _Rb_tree_color&
- _S_color(_Base_ptr __x) { return (_Link_type(__x)->_M_color); }
+ _S_color(_Base_ptr __x) { return __x->_M_color; }
static _Link_type
_S_minimum(_Link_type __x)
@@ -737,8 +736,8 @@
_M_empty_initialize();
else
{
- _S_color(this->_M_header) = _M_red;
- _M_root() = _M_copy(__x._M_root(), this->_M_header);
+ _S_color(&this->_M_header) = _M_red;
+ _M_root() = _M_copy(__x._M_root(), _M_end());
_M_leftmost() = _S_minimum(_M_root());
_M_rightmost() = _S_maximum(_M_root());
}
@@ -753,11 +752,11 @@
private:
void _M_empty_initialize()
{
- _S_color(this->_M_header) = _M_red; // used to distinguish header from
- // __root, in iterator.operator++
+ // Used to distinguish header from __root, in iterator.operator++
+ _S_color(&this->_M_header) = _M_red;
_M_root() = 0;
- _M_leftmost() = this->_M_header;
- _M_rightmost() = this->_M_header;
+ _M_leftmost() = _M_end();
+ _M_rightmost() = _M_end();
}
public:
@@ -772,10 +771,10 @@
begin() const { return _M_leftmost(); }
iterator
- end() { return this->_M_header; }
+ end() { return &this->_M_header; }
- const_iterator
- end() const { return this->_M_header; }
+ const_iterator
+ end() const { return const_cast<_Base_ptr>(&this->_M_header); }
reverse_iterator
rbegin() { return reverse_iterator(end()); }
@@ -799,12 +798,7 @@
max_size() const { return size_type(-1); }
void
- swap(_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>& __t)
- {
- std::swap(this->_M_header, __t._M_header);
- std::swap(_M_node_count, __t._M_node_count);
- std::swap(_M_key_compare, __t._M_key_compare);
- }
+ swap(_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>& __t);
// Insert/erase.
pair<iterator,bool>
@@ -845,9 +839,9 @@
if (_M_node_count != 0)
{
_M_erase(_M_root());
- _M_leftmost() = this->_M_header;
+ _M_leftmost() = _M_end();
_M_root() = 0;
- _M_rightmost() = this->_M_header;
+ _M_rightmost() = _M_end();
_M_node_count = 0;
}
}
@@ -955,12 +949,12 @@
if (__x._M_root() == 0)
{
_M_root() = 0;
- _M_leftmost() = this->_M_header;
- _M_rightmost() = this->_M_header;
+ _M_leftmost() = _M_end();
+ _M_rightmost() = _M_end();
}
else
{
- _M_root() = _M_copy(__x._M_root(), this->_M_header);
+ _M_root() = _M_copy(__x._M_root(), _M_end());
_M_leftmost() = _S_minimum(_M_root());
_M_rightmost() = _S_maximum(_M_root());
_M_node_count = __x._M_node_count;
@@ -979,13 +973,13 @@
_Link_type __y = (_Link_type) __y_;
_Link_type __z;
- if (__y == this->_M_header || __x != 0 ||
+ if (__y == &this->_M_header || __x != 0 ||
_M_key_compare(_KeyOfValue()(__v), _S_key(__y)))
{
__z = _M_create_node(__v);
_S_left(__y) = __z; // also makes _M_leftmost() = __z
- // when __y == _M_header
- if (__y == this->_M_header)
+ // when __y == &_M_header
+ if (__y == &this->_M_header)
{
_M_root() = __z;
_M_rightmost() = __z;
@@ -1004,7 +998,7 @@
_S_parent(__z) = __y;
_S_left(__z) = 0;
_S_right(__z) = 0;
- _Rb_tree_rebalance(__z, this->_M_header->_M_parent);
+ _Rb_tree_rebalance(__z, this->_M_header._M_parent);
++_M_node_count;
return iterator(__z);
}
@@ -1015,7 +1009,7 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
insert_equal(const _Val& __v)
{
- _Link_type __y = this->_M_header;
+ _Link_type __y = _M_end();
_Link_type __x = _M_root();
while (__x != 0)
{
@@ -1028,12 +1022,57 @@
template<typename _Key, typename _Val, typename _KeyOfValue,
typename _Compare, typename _Alloc>
+ void
+ _Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
+ swap(_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>& __t)
+ {
+ if (_M_root() == 0)
+ {
+ if (__t._M_root() != 0)
+ {
+ _M_root() = __t._M_root();
+ _M_leftmost() = __t._M_leftmost();
+ _M_rightmost() = __t._M_rightmost();
+ _M_root()->_M_parent = _M_end();
+
+ __t._M_root() = 0;
+ __t._M_leftmost() = __t._M_end();
+ __t._M_rightmost() = __t._M_end();
+ }
+ }
+ else if (__t._M_root() == 0)
+ {
+ __t._M_root() = _M_root();
+ __t._M_leftmost() = _M_leftmost();
+ __t._M_rightmost() = _M_rightmost();
+ __t._M_root()->_M_parent = __t._M_end();
+
+ _M_root() = 0;
+ _M_leftmost() = _M_end();
+ _M_rightmost() = _M_end();
+ }
+ else
+ {
+ std::swap(_M_root(),__t._M_root());
+ std::swap(_M_leftmost(),__t._M_leftmost());
+ std::swap(_M_rightmost(),__t._M_rightmost());
+
+ _M_root()->_M_parent = _M_end();
+ __t._M_root()->_M_parent = __t._M_end();
+ }
+ // No need to swap header's color as it does not change.
+ std::swap(this->_M_node_count, __t._M_node_count);
+ std::swap(this->_M_key_compare, __t._M_key_compare);
+ }
+
+ template<typename _Key, typename _Val, typename _KeyOfValue,
+ typename _Compare, typename _Alloc>
pair<typename _Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::iterator,
bool>
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
insert_unique(const _Val& __v)
{
- _Link_type __y = this->_M_header;
+ _Link_type __y = _M_end();
_Link_type __x = _M_root();
bool __comp = true;
while (__x != 0)
@@ -1060,7 +1099,7 @@
_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
insert_unique(iterator __position, const _Val& __v)
{
- if (__position._M_node == this->_M_header->_M_left)
+ if (__position._M_node == this->_M_header._M_left)
{
// begin()
if (size() > 0 &&
@@ -1070,7 +1109,7 @@
else
return insert_unique(__v).first;
}
- else if (__position._M_node == this->_M_header)
+ else if (__position._M_node == &this->_M_header)
{
// end()
if (_M_key_compare(_S_key(_M_rightmost()), _KeyOfValue()(__v)))
@@ -1102,7 +1141,7 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
insert_equal(iterator __position, const _Val& __v)
{
- if (__position._M_node == this->_M_header->_M_left)
+ if (__position._M_node == this->_M_header._M_left)
{
// begin()
if (size() > 0 &&
@@ -1112,7 +1151,7 @@
else
return insert_equal(__v);
}
- else if (__position._M_node == this->_M_header)
+ else if (__position._M_node == &this->_M_header)
{
// end()
if (!_M_key_compare(_KeyOfValue()(__v), _S_key(_M_rightmost())))
@@ -1168,9 +1207,9 @@
{
_Link_type __y =
(_Link_type) _Rb_tree_rebalance_for_erase(__position._M_node,
- this->_M_header->_M_parent,
- this->_M_header->_M_left,
- this->_M_header->_M_right);
+ this->_M_header._M_parent,
+ this->_M_header._M_left,
+ this->_M_header._M_right);
destroy_node(__y);
--_M_node_count;
}
@@ -1264,9 +1303,8 @@
typename _Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::iterator
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::find(const _Key& __k)
{
- _Link_type __y
- = this->_M_header; // Last node which is not less than __k.
- _Link_type __x = _M_root(); // Current node.
+ _Link_type __y = _M_end(); // Last node which is not less than __k.
+ _Link_type __x = _M_root(); // Current node.
while (__x != 0)
if (!_M_key_compare(_S_key(__x), __k))
@@ -1285,8 +1323,7 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
find(const _Key& __k) const
{
- _Link_type __y
- = this->_M_header; // Last node which is not less than __k.
+ _Link_type __y = _M_end(); // Last node which is not less than __k.
_Link_type __x = _M_root(); // Current node.
while (__x != 0)
@@ -1318,9 +1355,8 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
lower_bound(const _Key& __k)
{
- _Link_type __y
- = this->_M_header; /* Last node which is not less than __k. */
- _Link_type __x = _M_root(); /* Current node. */
+ _Link_type __y = _M_end(); // Last node which is not less than __k
+ _Link_type __x = _M_root(); // Current node.
while (__x != 0)
if (!_M_key_compare(_S_key(__x), __k))
@@ -1337,9 +1373,8 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
lower_bound(const _Key& __k) const
{
- _Link_type __y
- = this->_M_header; /* Last node which is not less than __k. */
- _Link_type __x = _M_root(); /* Current node. */
+ _Link_type __y = _M_end(); // Last node which is not less than __k.
+ _Link_type __x = _M_root(); // Current node.
while (__x != 0)
if (!_M_key_compare(_S_key(__x), __k))
@@ -1356,9 +1391,8 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
upper_bound(const _Key& __k)
{
- _Link_type __y
- = this->_M_header; /* Last node which is greater than __k. */
- _Link_type __x = _M_root(); /* Current node. */
+ _Link_type __y = _M_end(); // Last node which is greater than __k.
+ _Link_type __x = _M_root(); // Current node.
while (__x != 0)
if (_M_key_compare(__k, _S_key(__x)))
@@ -1375,9 +1409,8 @@
_Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::
upper_bound(const _Key& __k) const
{
- _Link_type __y
- = this->_M_header; /* Last node which is greater than __k. */
- _Link_type __x = _M_root(); /* Current node. */
+ _Link_type __y = _M_end(); // Last node which is greater than __k.
+ _Link_type __x = _M_root(); // Current node.
while (__x != 0)
if (_M_key_compare(__k, _S_key(__x)))
@@ -1434,8 +1467,8 @@
{
if (_M_node_count == 0 || begin() == end())
return _M_node_count == 0 && begin() == end() &&
- this->_M_header->_M_left == this->_M_header
- && this->_M_header->_M_right == this->_M_header;
+ this->_M_header._M_left == &this->_M_header &&
+ this->_M_header._M_right == &this->_M_header;
int __len = __black_count(_M_leftmost(), _M_root());
for (const_iterator __it = begin(); __it != end(); ++__it)