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From: "amonakov at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/108487] [10/11/12/13 Regression] ~20-30x slowdown in populating std::vector from std::ranges::iota_view Date: Sat, 21 Jan 2023 15:38:31 +0000 [thread overview] Message-ID: <bug-108487-4-Jsh8YtPOOW@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-108487-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108487 Alexander Monakov <amonakov at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|tree-optimization |libstdc++ --- Comment #3 from Alexander Monakov <amonakov at gcc dot gnu.org> --- libstdc++ uses a less efficient specialization of _M_range_initialize. With 10.2 headers, we use template<typename _ForwardIterator> void _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last, std::forward_iterator_tag) { const size_type __n = std::distance(__first, __last); this->_M_impl._M_start = this->_M_allocate(_S_check_init_len(__n, _M_get_Tp_allocator())); this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n; this->_M_impl._M_finish = std::__uninitialized_copy_a(__first, __last, this->_M_impl._M_start, _M_get_Tp_allocator()); } but with 10.4 headers, we use template<typename _InputIterator> void _M_range_initialize(_InputIterator __first, _InputIterator __last, std::input_iterator_tag) { try { for (; __first != __last; ++__first) emplace_back(*__first); } catch(...) { clear(); throw; } }
next prev parent reply other threads:[~2023-01-21 15:38 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-01-20 22:20 [Bug rtl-optimization/108487] New: " Mark_B53 at yahoo dot com 2023-01-21 11:48 ` [Bug tree-optimization/108487] [10/11/12/13 Regression] " amonakov at gcc dot gnu.org 2023-01-21 13:32 ` Mark_B53 at yahoo dot com 2023-01-21 15:38 ` amonakov at gcc dot gnu.org [this message] 2023-01-21 23:45 ` [Bug libstdc++/108487] " redi at gcc dot gnu.org 2023-01-21 23:50 ` redi at gcc dot gnu.org 2023-01-21 23:50 ` redi at gcc dot gnu.org 2023-01-22 3:07 ` Mark_B53 at yahoo dot com 2023-01-22 10:33 ` Mark_B53 at yahoo dot com 2023-01-22 17:14 ` redi at gcc dot gnu.org 2023-01-23 7:45 ` rguenth at gcc dot gnu.org 2023-03-27 11:03 ` rguenth at gcc dot gnu.org 2023-07-07 10:44 ` [Bug libstdc++/108487] [11/12/13/14 " rguenth at gcc dot gnu.org
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