{"id":2226772,"url":"http://patchwork.ozlabs.org/api/patches/2226772/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhup55wx16.gcc.gcc-TEST.tkaminsk.85.1.3@forge-stage.sourceware.org/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"","list_archive_url":null,"date":"2026-04-22T18:49:40","name":"[v1,03/10] Merged common mutable operations into mutable atomic base.","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"b6d38865eddec7caf38ce2a25a2f16652d4edcd5","submitter":{"id":93223,"url":"http://patchwork.ozlabs.org/api/people/93223/?format=json","name":"tkaminsk via Sourceware Forge","email":"forge-bot+tkaminsk@forge-stage.sourceware.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhup55wx16.gcc.gcc-TEST.tkaminsk.85.1.3@forge-stage.sourceware.org/mbox/","series":[{"id":501094,"url":"http://patchwork.ozlabs.org/api/series/501094/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=501094","date":"2026-04-22T18:49:39","name":"WIP: libstdc++: add support for cv-qualified types in atomic_ref (P3323R1)","version":1,"mbox":"http://patchwork.ozlabs.org/series/501094/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2226772/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2226772/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; 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server2.sourceware.org","From":"tkaminsk via Sourceware Forge\n ","Date":"Wed, 22 Apr 2026 18:49:40 +0000","Subject":"[PATCH v1 03/10] Merged common mutable operations into mutable atomic\n base.","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","To":"gcc-patches mailing list ","Message-ID":"\n ","X-Mailer":"batrachomyomachia","X-Pull-Request-Organization":"gcc","X-Pull-Request-Repository":"gcc-TEST","X-Pull-Request":"https://forge.sourceware.org/gcc/gcc-TEST/pulls/85","References":"\n ","In-Reply-To":"\n ","X-Patch-URL":"\n https://forge.sourceware.org/tkaminsk/gcc/commit/1970901d3cdc0ab61b8ad6a0fe76a1e683b34f14","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Reply-To":"gcc-patches mailing list ,\n tkaminsk@gcc.gnu.org","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"},"content":"From: Tomasz Kamiński \n\nThis removes a lot of code duplication.\n---\n libstdc++-v3/include/bits/atomic_base.h | 339 +++++-------------------\n 1 file changed, 69 insertions(+), 270 deletions(-)","diff":"diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h\nindex b8744ac49b45..4caa9e30b4dc 100644\n--- a/libstdc++-v3/include/bits/atomic_base.h\n+++ b/libstdc++-v3/include/bits/atomic_base.h\n@@ -1508,20 +1508,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n };\n #undef _GLIBCXX20_INIT\n \n+ // __atomic_ref_base provides the common APIs for const and\n+ // types,\n+ // __atomic_ref_base<_Tp> inhserits from __atomic_ref_base,\n+ // and provides the commonn APIs implementing constrains in [atomic.ref].\n+ // __atomic_ref<_Tp> inherits from __atomic_ref_base<_Tp> (const or not-const)\n+ // adds type specific mutating APIs.\n // atomic_ref inherits from __atomic_ref;\n- // __atomic_ref inherits from __atomic_ref_base.\n- //\n- // __atomic_ref_base provides the common APIs for const and non-const types;\n- // __atomic ref adds on top the APIs for non-const types, thus implementing\n- // the various constraints in [atomic.ref].\n \n template\n struct __atomic_ref_base;\n \n-\n template\n- class __atomic_ref_base\n+ struct __atomic_ref_base\n {\n+ private:\n using _Vt = remove_cv_t<_Tp>;\n \n static consteval bool\n@@ -1559,7 +1560,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n __atomic_ref_base& operator=(const __atomic_ref_base&) = delete;\n \n explicit\n- __atomic_ref_base(_Tp& __t) : _M_ptr(std::__addressof(__t))\n+ __atomic_ref_base(const _Tp& __t)\n+ : _M_ptr(const_cast<_Tp*>(std::__addressof(__t)))\n {\n \t__glibcxx_assert(((__UINTPTR_TYPE__)_M_ptr % required_alignment) == 0);\n }\n@@ -1588,60 +1590,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n _Tp* _M_ptr;\n };\n \n- template,\n-\t bool = is_integral_v<_Tp> && !is_same_v, bool>,\n-\t bool = is_floating_point_v<_Tp>,\n-\t bool = is_pointer_v<_Tp>>\n- struct __atomic_ref;\n-\n- // base classes for const qualified types\n template\n- struct __atomic_ref<_Tp, true, false, false, false>\n- : __atomic_ref_base<_Tp>\n+ struct __atomic_ref_base\n+ : __atomic_ref_base\n {\n- explicit\n- __atomic_ref(_Tp& __t) : __atomic_ref_base<_Tp>(__t)\n- { }\n- };\n-\n- template\n- struct __atomic_ref<_Tp, true, false, false, true>\n- : __atomic_ref_base<_Tp>\n- {\n- using difference_type = ptrdiff_t;\n-\n- explicit\n- __atomic_ref(_Tp& __t) : __atomic_ref_base<_Tp>(__t)\n- { }\n- };\n-\n- template\n- struct __atomic_ref<_Tp, true, _IsIntegral, _IsFloatingPoint, false>\n- : __atomic_ref_base<_Tp>\n- {\n- using difference_type = typename __atomic_ref_base<_Tp>::value_type;\n+ using value_type = typename __atomic_ref_base::value_type;\n \n explicit\n- __atomic_ref(_Tp& __t) : __atomic_ref_base<_Tp>(__t)\n+ __atomic_ref_base(_Tp& __t) : __atomic_ref_base(__t)\n { }\n- };\n-\n-\n- // base class for non-integral, non-floating-point, non-pointer types\n- template\n- struct __atomic_ref<_Tp, false, false, false, false>\n- : __atomic_ref_base<_Tp>\n- {\n- using value_type = typename __atomic_ref_base<_Tp>::value_type;\n- explicit\n- __atomic_ref(_Tp& __t) : __atomic_ref_base<_Tp>(__t)\n- { }\n-\n- void\n- store(value_type __t, memory_order __m = memory_order_seq_cst) const noexcept\n- { __atomic_impl::store(this->_M_ptr, __t, __m); }\n-\n value_type\n operator=(value_type __t) const noexcept\n {\n@@ -1649,6 +1606,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n \treturn __t;\n }\n \n+ void\n+ store(value_type __t, memory_order __m = memory_order_seq_cst) const noexcept\n+ { __atomic_impl::store(this->_M_ptr, __t, __m); }\n+\n value_type\n exchange(value_type __desired, memory_order __m = memory_order_seq_cst)\n const noexcept\n@@ -1705,83 +1666,56 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n #endif // __glibcxx_atomic_wait\n };\n \n- // base class for atomic_ref\n+ template,\n+\t bool = is_integral_v<_Tp> && !is_same_v, bool>,\n+\t bool = is_floating_point_v<_Tp>,\n+\t bool = is_pointer_v<_Tp>>\n+ struct __atomic_ref;\n+\n+ // base classes for const qualified types\n template\n- struct __atomic_ref<_Tp, false, true, false, false>\n+ struct __atomic_ref<_Tp, true, false, false, false>\n : __atomic_ref_base<_Tp>\n {\n- using value_type = typename __atomic_ref_base<_Tp>::value_type;\n- using difference_type = value_type;\n-\n- explicit\n- __atomic_ref(_Tp& __t) : __atomic_ref_base<_Tp>(__t)\n- { }\n-\n- value_type\n- operator=(value_type __t) const noexcept\n- {\n-\tthis->store(__t);\n-\treturn __t;\n- }\n-\n- void\n- store(value_type __t, memory_order __m = memory_order_seq_cst) const noexcept\n- { __atomic_impl::store(this->_M_ptr, __t, __m); }\n-\n- value_type\n- exchange(value_type __desired,\n-\t memory_order __m = memory_order_seq_cst) const noexcept\n- { return __atomic_impl::exchange(this->_M_ptr, __desired, __m); }\n-\n- bool\n- compare_exchange_weak(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __success,\n-\t\t\t memory_order __failure) const noexcept\n- {\n-\treturn __atomic_impl::compare_exchange_weak(\n-\t\t this->_M_ptr, __expected, __desired, __success, __failure);\n- }\n-\n- bool\n- compare_exchange_strong(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __success,\n-\t\t\t memory_order __failure) const noexcept\n- {\n-\treturn __atomic_impl::compare_exchange_strong(\n-\t\t this->_M_ptr, __expected, __desired, __success, __failure);\n- }\n-\n- bool\n- compare_exchange_weak(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __order = memory_order_seq_cst)\n- const noexcept\n- {\n-\treturn compare_exchange_weak(__expected, __desired, __order,\n- __cmpexch_failure_order(__order));\n- }\n+ using __atomic_ref_base<_Tp>::__atomic_ref_base;\n+ };\n \n- bool\n- compare_exchange_strong(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __order = memory_order_seq_cst)\n- const noexcept\n- {\n-\treturn compare_exchange_strong(__expected, __desired, __order,\n-\t\t\t\t __cmpexch_failure_order(__order));\n- }\n+ template\n+ struct __atomic_ref<_Tp, true, false, false, true>\n+ : __atomic_ref_base<_Tp>\n+ {\n+ using difference_type = ptrdiff_t;\n+ using __atomic_ref_base<_Tp>::__atomic_ref_base;\n+ };\n \n-#if __glibcxx_atomic_wait\n- _GLIBCXX_ALWAYS_INLINE void\n- notify_one() const noexcept\n- { __atomic_impl::notify_one(this->_M_ptr); }\n+ template\n+ struct __atomic_ref<_Tp, true, _IsIntegral, _IsFloatingPoint, false>\n+ : __atomic_ref_base<_Tp>\n+ {\n+ using difference_type = typename __atomic_ref_base<_Tp>::value_type;\n+ using __atomic_ref_base<_Tp>::__atomic_ref_base;\n+ };\n \n- // TODO add const volatile overload\n+ // base class for non-integral, non-floating-point, non-pointer types\n+ template\n+ struct __atomic_ref<_Tp, false, false, false, false>\n+ : __atomic_ref_base<_Tp>\n+ {\n+ using __atomic_ref_base<_Tp>::__atomic_ref_base;\n+ using __atomic_ref_base<_Tp>::operator=;\n+ };\n \n- _GLIBCXX_ALWAYS_INLINE void\n- notify_all() const noexcept\n- { __atomic_impl::notify_all(this->_M_ptr); }\n+ // base class for atomic_ref\n+ template\n+ struct __atomic_ref<_Tp, false, true, false, false>\n+ : __atomic_ref_base<_Tp>\n+ {\n+ using value_type = typename __atomic_ref_base<_Tp>::value_type;\n+ using difference_type = value_type;\n \n- // TODO add const volatile overload\n-#endif // __glibcxx_atomic_wait\n+ using __atomic_ref_base<_Tp>::__atomic_ref_base;\n+ using __atomic_ref_base<_Tp>::operator=;\n \n value_type\n fetch_add(value_type __i,\n@@ -1853,76 +1787,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n using value_type = typename __atomic_ref_base<_Fp>::value_type;\n using difference_type = value_type;\n \n- explicit\n- __atomic_ref(_Fp& __t) : __atomic_ref_base<_Fp>(__t)\n- { }\n-\n- value_type\n- operator=(value_type __t) const noexcept\n- {\n-\tthis->store(__t);\n-\treturn __t;\n- }\n-\n- void\n- store(value_type __t, memory_order __m = memory_order_seq_cst) const noexcept\n- { __atomic_impl::store(this->_M_ptr, __t, __m); }\n-\n- _Fp\n- exchange(value_type __desired,\n-\t memory_order __m = memory_order_seq_cst) const noexcept\n- { return __atomic_impl::exchange(this->_M_ptr, __desired, __m); }\n-\n- bool\n- compare_exchange_weak(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __success,\n-\t\t\t memory_order __failure) const noexcept\n- {\n-\treturn __atomic_impl::compare_exchange_weak(\n-\t\t this->_M_ptr, __expected, __desired, __success, __failure);\n- }\n-\n- bool\n- compare_exchange_strong(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __success,\n-\t\t\t memory_order __failure) const noexcept\n- {\n-\treturn __atomic_impl::compare_exchange_strong(\n-\t\t this->_M_ptr, __expected, __desired, __success, __failure);\n- }\n-\n- bool\n- compare_exchange_weak(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __order = memory_order_seq_cst)\n- const noexcept\n- {\n-\treturn compare_exchange_weak(__expected, __desired, __order,\n- __cmpexch_failure_order(__order));\n- }\n-\n- bool\n- compare_exchange_strong(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __order = memory_order_seq_cst)\n- const noexcept\n- {\n-\treturn compare_exchange_strong(__expected, __desired, __order,\n-\t\t\t\t __cmpexch_failure_order(__order));\n- }\n-\n-#if __glibcxx_atomic_wait\n- _GLIBCXX_ALWAYS_INLINE void\n- notify_one() const noexcept\n- { __atomic_impl::notify_one(this->_M_ptr); }\n-\n- // TODO add const volatile overload\n-\n- _GLIBCXX_ALWAYS_INLINE void\n- notify_all() const noexcept\n- { __atomic_impl::notify_all(this->_M_ptr); }\n-\n- // TODO add const volatile overload\n-#endif // __glibcxx_atomic_wait\n-\n+ using __atomic_ref_base<_Fp>::__atomic_ref_base;\n+ using __atomic_ref_base<_Fp>::operator=;\n+ \n value_type\n fetch_add(value_type __i,\n \t\tmemory_order __m = memory_order_seq_cst) const noexcept\n@@ -1943,83 +1810,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n };\n \n // base class for atomic_ref\n- template\n- struct __atomic_ref<_Tp, false, false, false, true>\n- : __atomic_ref_base<_Tp>\n+ template\n+ struct __atomic_ref<_Pt, false, false, false, true>\n+ : __atomic_ref_base<_Pt>\n {\n- using value_type = typename __atomic_ref_base<_Tp>::value_type;\n+ using value_type = typename __atomic_ref_base<_Pt>::value_type;\n using difference_type = ptrdiff_t;\n \n- explicit\n- __atomic_ref(_Tp& __t) : __atomic_ref_base<_Tp>(__t)\n- { }\n-\n- value_type\n- operator=(value_type __t) const noexcept\n- {\n-\tthis->store(__t);\n-\treturn __t;\n- }\n-\n- void\n- store(value_type __t, memory_order __m = memory_order_seq_cst) const noexcept\n- { __atomic_impl::store(this->_M_ptr, __t, __m); }\n-\n- value_type\n- exchange(value_type __desired,\n-\t memory_order __m = memory_order_seq_cst) const noexcept\n- { return __atomic_impl::exchange(this->_M_ptr, __desired, __m); }\n-\n- bool\n- compare_exchange_weak(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __success,\n-\t\t\t memory_order __failure) const noexcept\n- {\n-\treturn __atomic_impl::compare_exchange_weak(\n-\t\t this->_M_ptr, __expected, __desired, __success, __failure);\n- }\n-\n- bool\n- compare_exchange_strong(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __success,\n-\t\t\t memory_order __failure) const noexcept\n- {\n-\treturn __atomic_impl::compare_exchange_strong(\n-\t\t this->_M_ptr, __expected, __desired, __success, __failure);\n- }\n-\n- bool\n- compare_exchange_weak(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __order = memory_order_seq_cst)\n- const noexcept\n- {\n-\treturn compare_exchange_weak(__expected, __desired, __order,\n- __cmpexch_failure_order(__order));\n- }\n-\n- bool\n- compare_exchange_strong(value_type& __expected, value_type __desired,\n-\t\t\t memory_order __order = memory_order_seq_cst)\n- const noexcept\n- {\n-\treturn compare_exchange_strong(__expected, __desired, __order,\n-\t\t\t\t __cmpexch_failure_order(__order));\n- }\n-\n-#if __glibcxx_atomic_wait\n- _GLIBCXX_ALWAYS_INLINE void\n- notify_one() const noexcept\n- { __atomic_impl::notify_one(this->_M_ptr); }\n-\n- // TODO add const volatile overload\n-\n- _GLIBCXX_ALWAYS_INLINE void\n- notify_all() const noexcept\n- { __atomic_impl::notify_all(this->_M_ptr); }\n-\n- // TODO add const volatile overload\n-#endif // __glibcxx_atomic_wait\n-\n+ using __atomic_ref_base<_Pt>::__atomic_ref_base;\n+ using __atomic_ref_base<_Pt>::operator=;\n _GLIBCXX_ALWAYS_INLINE value_type\n fetch_add(difference_type __d,\n \t\tmemory_order __m = memory_order_seq_cst) const noexcept\n","prefixes":["v1","03/10"]}