http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54393
--- Comment #3 from Adhemerval Zanella <azanella at linux dot vnet.ibm.com> 2012-08-28 18:49:42 UTC --- The default algorithm used on both std::string and __gnu_cxx::__vstring appends data char by char. However, std::string also provides an template specialization for both char and wchar_t (defined in src/istream.cc) which appends the data from the stream using larger buffer (which is calculated by finding the delimiter). Based on that and following how std::string provides its template specialization, I'm proposing a fix for the performance issue. This was made against gcc-4.6 (I still working a patch for trunk) and I only update the baseline_symbols for PPC64 (since it a still RFC patch).
