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gcc/libstdc++-v3 ChangeLog include/bits/basic_ ...
- From: paolo at gcc dot gnu dot org
- To: gcc-cvs at gcc dot gnu dot org, libstdc++-cvs at gcc dot gnu dot org
- Date: 13 Jun 2003 20:59:42 -0000
- Subject: gcc/libstdc++-v3 ChangeLog include/bits/basic_ ...
CVSROOT: /cvs/gcc
Module name: gcc
Changes by: paolo@gcc.gnu.org 2003-06-13 20:59:42
Modified files:
libstdc++-v3 : ChangeLog
libstdc++-v3/include/bits: basic_string.h basic_string.tcc
Log message:
2003-06-13 Nathan C. Myers <ncm-nospam@cantrip.org>
Avoid multi-processor bus contention on increment/decrement-and-
test of the reference count in the empty-string object, by comparing
addresses first, and never touching the reference count of the empty-
string object.
* include/bits/basic_string.h:
(_S_empty_rep_storage): Move into basic_string<>::_Rep for use by its
members.
(_Rep::_S_empty_rep()): New accessor.
(_Rep::_M_length, _Rep::_M_capacity, _Rep::_M_references): Move to
a base class _Rep_base.
(_Rep::_M_dispose, _Rep::_M_refcopy): Check for the empty string.
(basic_string()): Change to use _M_refdata() in place of _M_refcopy(),
since no longer must increment its refcount.
* include/bits/basic_string.tcc:
(_Rep::_M_destroy, _M_leak_hard): Check for the empty string and
return immediately. The former might be unnecessary. The latter
prevents begin() and end() from cloning it unnecessarily.
(_S_construct(_InIterator, _InIterator, const _Alloc&,
input_iterator_tag), _S_construct(_InIterator, _InIterator,
const _Alloc&, forward_iterator_tag), _S_construct(size_type, _CharT,
const _Alloc&)): Change to use _M_refdata() in place of _M_refcopy().
(_M_mutate): Check for the empty string and treat it as shared.
This is necessary here because _M_mutate is sometimes called with
all-zero arguments; in all other uses of _M_is_shared, the test comes
out right anyhow.
Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.1768&r2=1.1769
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/basic_string.h.diff?cvsroot=gcc&r1=1.33&r2=1.34
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/basic_string.tcc.diff?cvsroot=gcc&r1=1.37&r2=1.38