Re: [patch] Use abi_tag attribute on std::list

[Jonathan Wakely]

On 03/10/14 15:49 +0100, Jonathan Wakely wrote:

On 03/10/14 16:25 +0200, Marc Glisse wrote:

Do you mind if I move (in a future patch once yours is committed) _M_size into _M_impl::_M_node as suggested in PR 61347?

Gah, that's where I had it until earlier this week, and I looked at it
and wondered why it was in the _List_impl class (because you only need
one member in there to benefit from the empty base-class
optimisation).

I will move it back there, since I already have that code on another
branch, so there's no point making you change the code to match
something I've already got!

Marc, this is the relative diff to go back to what I had earlier, with
the size in the _List_impl in case you want to aply it locally (the
dg-error tests are off-by-one with this patch)


diff --git a/libstdc++-v3/include/bits/stl_list.h 
b/libstdc++-v3/include/bits/stl_list.h
index 3a56daf..4dbdaf0 100644
--- a/libstdc++-v3/include/bits/stl_list.h
+++ b/libstdc++-v3/include/bits/stl_list.h
@@ -333,6 +333,17 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       : public _Node_alloc_type
       {
        __detail::_List_node_base _M_node;
+#if _GLIBCXX_USE_CXX11_ABI
+       size_t                    _M_size;
+
+       // return the stored size
+       size_t _M_node_count() const { return _M_size; }
+#else
+       // count the number of nodes
+       size_t _M_node_count() const
+       { return _S_distance(_M_node._M_next, std::__addressof(_M_node)); }
+#endif
+
        _List_impl()
        : _Node_alloc_type(), _M_node()
        { }
@@ -350,24 +361,27 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
       _List_impl _M_impl;
 
-#if _GLIBCXX_USE_CXX11_ABI
-      size_t    _M_size;
+      _List_node<_Tp>*
+      _M_get_node()
+      { return _M_impl._Node_alloc_type::allocate(1); }
+
+      void
+      _M_put_node(_List_node<_Tp>* __p) _GLIBCXX_NOEXCEPT
+      { _M_impl._Node_alloc_type::deallocate(__p, 1); }
 
-      size_t _M_get_size() const { return _M_size; }
+#if _GLIBCXX_USE_CXX11_ABI
+      size_t _M_get_size() const { return _M_impl._M_size; }
 
-      void _M_set_size(size_t __n) { _M_size = __n; }
+      void _M_set_size(size_t __n) { _M_impl._M_size = __n; }
 
-      void _M_inc_size(size_t __n) { _M_size += __n; }
+      void _M_inc_size(size_t __n) { _M_impl._M_size += __n; }
 
-      void _M_dec_size(size_t __n) { _M_size -= __n; }
+      void _M_dec_size(size_t __n) { _M_impl._M_size -= __n; }
 
       size_t
       _M_distance(const __detail::_List_node_base* __first,
                  const __detail::_List_node_base* __last) const
       { return _S_distance(__first, __last); }
-
-      // return the stored size
-      size_t _M_node_count() const { return _M_size; }
 #else
       // dummy implementations used when the size is not stored
       size_t _M_get_size() const { return 0; }
@@ -375,23 +389,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       void _M_inc_size(size_t) { }
       void _M_dec_size(size_t) { }
       size_t _M_distance(const void*, const void*) const { return 0; }
-
-      // count the number of nodes
-      size_t _M_node_count() const
-      {
-       return _S_distance(_M_impl._M_node._M_next,
-                          std::__addressof(_M_impl._M_node));
-      }
 #endif
 
-      _List_node<_Tp>*
-      _M_get_node()
-      { return _M_impl._Node_alloc_type::allocate(1); }
-
-      void
-      _M_put_node(_List_node<_Tp>* __p) _GLIBCXX_NOEXCEPT
-      { _M_impl._Node_alloc_type::deallocate(__p, 1); }
-
   public:
       typedef _Alloc allocator_type;
 
@@ -941,7 +940,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       /**  Returns the number of elements in the %list.  */
       size_type
       size() const _GLIBCXX_NOEXCEPT
-      { return this->_M_node_count(); }
+      { return this->_M_impl._M_node_count(); }
 
       /**  Returns the size() of the largest possible %list.  */
       size_type