head 1.1; branch 1.1.1; access; symbols netbsd-11-0-RC5:1.1.1.1 netbsd-11-0-RC4:1.1.1.1 netbsd-11-0-RC3:1.1.1.1 netbsd-11-0-RC2:1.1.1.1 netbsd-11-0-RC1:1.1.1.1 gcc-14-3-0:1.1.1.2 perseant-exfatfs-base-20250801:1.1.1.1 netbsd-11:1.1.1.1.0.4 netbsd-11-base:1.1.1.1 gcc-12-5-0:1.1.1.1 perseant-exfatfs-base-20240630:1.1.1.1 gcc-12-4-0:1.1.1.1 perseant-exfatfs:1.1.1.1.0.2 perseant-exfatfs-base:1.1.1.1 gcc-12-3-0:1.1.1.1 FSF:1.1.1; locks; strict; comment @# @; 1.1 date 2023.07.30.05.21.20; author mrg; state Exp; branches 1.1.1.1; next ; commitid tk6nV4mbc9nVEMyE; 1.1.1.1 date 2023.07.30.05.21.20; author mrg; state Exp; branches; next 1.1.1.2; commitid tk6nV4mbc9nVEMyE; 1.1.1.2 date 2025.09.13.23.45.48; author mrg; state Exp; branches; next ; commitid KwhwN4krNWa6XBaG; desc @@ 1.1 log @Initial revision @ text @// -*- C++ -*- // Copyright (C) 2020-2022 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // . // This implementation is based on libcxx/include/barrier //===-- barrier.h --------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===---------------------------------------------------------------===// /** @@file include/barrier * This is a Standard C++ Library header. */ #ifndef _GLIBCXX_BARRIER #define _GLIBCXX_BARRIER 1 #pragma GCC system_header #if __cplusplus > 201703L #include #if __cpp_lib_atomic_wait && __cpp_aligned_new #include #include #include #define __cpp_lib_barrier 201907L namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION struct __empty_completion { _GLIBCXX_ALWAYS_INLINE void operator()() noexcept { } }; /* The default implementation of __tree_barrier is a classic tree barrier. It looks different from literature pseudocode for two main reasons: 1. Threads that call into std::barrier functions do not provide indices, so a numbering step is added before the actual barrier algorithm, appearing as an N+1 round to the N rounds of the tree barrier. 2. A great deal of attention has been paid to avoid cache line thrashing by flattening the tree structure into cache-line sized arrays, that are indexed in an efficient way. */ enum class __barrier_phase_t : unsigned char { }; template class __tree_barrier { using __atomic_phase_ref_t = std::__atomic_ref<__barrier_phase_t>; using __atomic_phase_const_ref_t = std::__atomic_ref; static constexpr auto __phase_alignment = __atomic_phase_ref_t::required_alignment; using __tickets_t = std::array<__barrier_phase_t, 64>; struct alignas(64) /* naturally-align the heap state */ __state_t { alignas(__phase_alignment) __tickets_t __tickets; }; ptrdiff_t _M_expected; unique_ptr<__state_t[]> _M_state; __atomic_base _M_expected_adjustment; _CompletionF _M_completion; alignas(__phase_alignment) __barrier_phase_t _M_phase; bool _M_arrive(__barrier_phase_t __old_phase, size_t __current) { const auto __old_phase_val = static_cast(__old_phase); const auto __half_step = static_cast<__barrier_phase_t>(__old_phase_val + 1); const auto __full_step = static_cast<__barrier_phase_t>(__old_phase_val + 2); size_t __current_expected = _M_expected; __current %= ((_M_expected + 1) >> 1); for (int __round = 0; ; ++__round) { if (__current_expected <= 1) return true; size_t const __end_node = ((__current_expected + 1) >> 1), __last_node = __end_node - 1; for ( ; ; ++__current) { if (__current == __end_node) __current = 0; auto __expect = __old_phase; __atomic_phase_ref_t __phase(_M_state[__current] .__tickets[__round]); if (__current == __last_node && (__current_expected & 1)) { if (__phase.compare_exchange_strong(__expect, __full_step, memory_order_acq_rel)) break; // I'm 1 in 1, go to next __round } else if (__phase.compare_exchange_strong(__expect, __half_step, memory_order_acq_rel)) { return false; // I'm 1 in 2, done with arrival } else if (__expect == __half_step) { if (__phase.compare_exchange_strong(__expect, __full_step, memory_order_acq_rel)) break; // I'm 2 in 2, go to next __round } } __current_expected = __last_node + 1; __current >>= 1; } } public: using arrival_token = __barrier_phase_t; static constexpr ptrdiff_t max() noexcept { return __PTRDIFF_MAX__; } __tree_barrier(ptrdiff_t __expected, _CompletionF __completion) : _M_expected(__expected), _M_expected_adjustment(0), _M_completion(move(__completion)), _M_phase(static_cast<__barrier_phase_t>(0)) { size_t const __count = (_M_expected + 1) >> 1; _M_state = std::make_unique<__state_t[]>(__count); } [[nodiscard]] arrival_token arrive(ptrdiff_t __update) { std::hash __hasher; size_t __current = __hasher(std::this_thread::get_id()); __atomic_phase_ref_t __phase(_M_phase); const auto __old_phase = __phase.load(memory_order_relaxed); const auto __cur = static_cast(__old_phase); for(; __update; --__update) { if(_M_arrive(__old_phase, __current)) { _M_completion(); _M_expected += _M_expected_adjustment.load(memory_order_relaxed); _M_expected_adjustment.store(0, memory_order_relaxed); auto __new_phase = static_cast<__barrier_phase_t>(__cur + 2); __phase.store(__new_phase, memory_order_release); __phase.notify_all(); } } return __old_phase; } void wait(arrival_token&& __old_phase) const { __atomic_phase_const_ref_t __phase(_M_phase); auto const __test_fn = [=] { return __phase.load(memory_order_acquire) != __old_phase; }; std::__atomic_wait_address(&_M_phase, __test_fn); } void arrive_and_drop() { _M_expected_adjustment.fetch_sub(1, memory_order_relaxed); (void)arrive(1); } }; template class barrier { // Note, we may introduce a "central" barrier algorithm at some point // for more space constrained targets using __algorithm_t = __tree_barrier<_CompletionF>; __algorithm_t _M_b; public: class arrival_token final { public: arrival_token(arrival_token&&) = default; arrival_token& operator=(arrival_token&&) = default; ~arrival_token() = default; private: friend class barrier; using __token = typename __algorithm_t::arrival_token; explicit arrival_token(__token __tok) noexcept : _M_tok(__tok) { } __token _M_tok; }; static constexpr ptrdiff_t max() noexcept { return __algorithm_t::max(); } explicit barrier(ptrdiff_t __count, _CompletionF __completion = _CompletionF()) : _M_b(__count, std::move(__completion)) { } barrier(barrier const&) = delete; barrier& operator=(barrier const&) = delete; [[nodiscard]] arrival_token arrive(ptrdiff_t __update = 1) { return arrival_token{_M_b.arrive(__update)}; } void wait(arrival_token&& __phase) const { _M_b.wait(std::move(__phase._M_tok)); } void arrive_and_wait() { wait(arrive()); } void arrive_and_drop() { _M_b.arrive_and_drop(); } }; _GLIBCXX_END_NAMESPACE_VERSION } // namespace #endif // __cpp_lib_atomic_wait && __cpp_aligned_new #endif // __cplusplus > 201703L #endif // _GLIBCXX_BARRIER @ 1.1.1.1 log @initial import of GCC 12.3.0. major changes in GCC 11 included: - The default mode for C++ is now -std=gnu++17 instead of -std=gnu++14. - When building GCC itself, the host compiler must now support C++11, rather than C++98. - Some short options of the gcov tool have been renamed: -i to -j and -j to -H. - ThreadSanitizer improvements. - Introduce Hardware-assisted AddressSanitizer support. - For targets that produce DWARF debugging information GCC now defaults to DWARF version 5. This can produce up to 25% more compact debug information compared to earlier versions. - Many optimisations. - The existing malloc attribute has been extended so that it can be used to identify allocator/deallocator API pairs. A pair of new -Wmismatched-dealloc and -Wmismatched-new-delete warnings are added. - Other new warnings: -Wsizeof-array-div, enabled by -Wall, warns about divisions of two sizeof operators when the first one is applied to an array and the divisor does not equal the size of the array element. -Wstringop-overread, enabled by default, warns about calls to string functions reading past the end of the arrays passed to them as arguments. -Wtsan, enabled by default, warns about unsupported features in ThreadSanitizer (currently std::atomic_thread_fence). - Enchanced warnings: -Wfree-nonheap-object detects many more instances of calls to deallocation functions with pointers not returned from a dynamic memory allocation function. -Wmaybe-uninitialized diagnoses passing pointers or references to uninitialized memory to functions taking const-qualified arguments. -Wuninitialized detects reads from uninitialized dynamically allocated memory. -Warray-parameter warns about functions with inconsistent array forms. -Wvla-parameter warns about functions with inconsistent VLA forms. - Several new features from the upcoming C2X revision of the ISO C standard are supported with -std=c2x and -std=gnu2x. - Several C++20 features have been implemented. - The C++ front end has experimental support for some of the upcoming C++23 draft. - Several new C++ warnings. - Enhanced Arm, AArch64, x86, and RISC-V CPU support. - The implementation of how program state is tracked within -fanalyzer has been completely rewritten with many enhancements. see https://gcc.gnu.org/gcc-11/changes.html for a full list. major changes in GCC 12 include: - An ABI incompatibility between C and C++ when passing or returning by value certain aggregates containing zero width bit-fields has been discovered on various targets. x86-64, ARM and AArch64 will always ignore them (so there is a C ABI incompatibility between GCC 11 and earlier with GCC 12 or later), PowerPC64 ELFv2 always take them into account (so there is a C++ ABI incompatibility, GCC 4.4 and earlier compatible with GCC 12 or later, incompatible with GCC 4.5 through GCC 11). RISC-V has changed the handling of these already starting with GCC 10. As the ABI requires, MIPS takes them into account handling function return values so there is a C++ ABI incompatibility with GCC 4.5 through 11. - STABS: Support for emitting the STABS debugging format is deprecated and will be removed in the next release. All ports now default to emit DWARF (version 2 or later) debugging info or are obsoleted. - Vectorization is enabled at -O2 which is now equivalent to the original -O2 -ftree-vectorize -fvect-cost-model=very-cheap. - GCC now supports the ShadowCallStack sanitizer. - Support for __builtin_shufflevector compatible with the clang language extension was added. - Support for attribute unavailable was added. - Support for __builtin_dynamic_object_size compatible with the clang language extension was added. - New warnings: -Wbidi-chars warns about potentially misleading UTF-8 bidirectional control characters. -Warray-compare warns about comparisons between two operands of array type. - Some new features from the upcoming C2X revision of the ISO C standard are supported with -std=c2x and -std=gnu2x. - Several C++23 features have been implemented. - Many C++ enhancements across warnings and -f options. see https://gcc.gnu.org/gcc-12/changes.html for a full list. @ text @@ 1.1.1.2 log @initial import of GCC 14.3.0. major changes in GCC 13: - improved sanitizer - zstd debug info compression - LTO improvements - SARIF based diagnostic support - new warnings: -Wxor-used-as-pow, -Wenum-int-mismatch, -Wself-move, -Wdangling-reference - many new -Wanalyzer* specific warnings - enhanced warnings: -Wpessimizing-move, -Wredundant-move - new attributes to mark file descriptors, c++23 "assume" - several C23 features added - several C++23 features added - many new features for Arm, x86, RISC-V major changes in GCC 14: - more strict C99 or newer support - ia64* marked deprecated (but seemingly still in GCC 15.) - several new hardening features - support for "hardbool", which can have user supplied values of true/false - explicit support for stack scrubbing upon function exit - better auto-vectorisation support - added clang-compatible __has_feature and __has_extension - more C23, including -std=c23 - several C++26 features added - better diagnostics in C++ templates - new warnings: -Wnrvo, Welaborated-enum-base - many new features for Arm, x86, RISC-V - possible ABI breaking change for SPARC64 and small structures with arrays of floats. @ text @d3 1 a3 1 // Copyright (C) 2020-2024 Free Software Foundation, Inc. d43 1 a43 6 #include // threading primitive #define __glibcxx_want_barrier #include #ifdef __cpp_lib_barrier // C++ >= 20 && __cpp_aligned_new && lib_atomic_wait d45 1 d51 2 d262 2 a263 1 #endif // __cpp_lib_barrier @