hxy9243 created this revision.
hxy9243 added reviewers: sebpop, hiraditya, wmi.
hxy9243 added a subscriber: cfe-commits.
hxy9243 set the repository for this revision to rL LLVM.
This patch moves some existing functions from the memory.cpp to the memory
header file, so that they could be properly inlined, which gives potential
optimization opportunities and performance benefits.
Repository:
rL LLVM
https://reviews.llvm.org/D24991
Files:
libcxx/include/atomic_support.h
libcxx/include/memory
libcxx/src/include/atomic_support.h
libcxx/src/memory.cpp
libcxx/src/mutex.cpp
Index: libcxx/src/mutex.cpp
===================================================================
--- libcxx/src/mutex.cpp
+++ libcxx/src/mutex.cpp
@@ -12,7 +12,7 @@
#include "limits"
#include "system_error"
#include "cassert"
-#include "include/atomic_support.h"
+#include "atomic_support.h"
_LIBCPP_BEGIN_NAMESPACE_STD
#ifndef _LIBCPP_HAS_NO_THREADS
Index: libcxx/src/memory.cpp
===================================================================
--- libcxx/src/memory.cpp
+++ libcxx/src/memory.cpp
@@ -13,85 +13,17 @@
#include "mutex"
#include "thread"
#endif
-#include "include/atomic_support.h"
+#include "atomic_support.h"
_LIBCPP_BEGIN_NAMESPACE_STD
-namespace
-{
-
-// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
-// should be sufficient for thread safety.
-// See https://llvm.org/bugs/show_bug.cgi?id=22803
-template <class T>
-inline T
-increment(T& t) _NOEXCEPT
-{
- return __libcpp_atomic_add(&t, 1, _AO_Relaxed);
-}
-
-template <class T>
-inline T
-decrement(T& t) _NOEXCEPT
-{
- return __libcpp_atomic_add(&t, -1, _AO_Acq_Rel);
-}
-
-} // namespace
-
const allocator_arg_t allocator_arg = allocator_arg_t();
bad_weak_ptr::~bad_weak_ptr() _NOEXCEPT {}
-const char*
-bad_weak_ptr::what() const _NOEXCEPT
-{
- return "bad_weak_ptr";
-}
+__shared_count::~__shared_count() {}
-__shared_count::~__shared_count()
-{
-}
-
-void
-__shared_count::__add_shared() _NOEXCEPT
-{
- increment(__shared_owners_);
-}
-
-bool
-__shared_count::__release_shared() _NOEXCEPT
-{
- if (decrement(__shared_owners_) == -1)
- {
- __on_zero_shared();
- return true;
- }
- return false;
-}
-
-__shared_weak_count::~__shared_weak_count()
-{
-}
-
-void
-__shared_weak_count::__add_shared() _NOEXCEPT
-{
- __shared_count::__add_shared();
-}
-
-void
-__shared_weak_count::__add_weak() _NOEXCEPT
-{
- increment(__shared_weak_owners_);
-}
-
-void
-__shared_weak_count::__release_shared() _NOEXCEPT
-{
- if (__shared_count::__release_shared())
- __release_weak();
-}
+__shared_weak_count::~__shared_weak_count() {}
void
__shared_weak_count::__release_weak() _NOEXCEPT
Index: libcxx/src/include/atomic_support.h
===================================================================
--- libcxx/src/include/atomic_support.h
+++ /dev/null
@@ -1,158 +0,0 @@
-//===----------------------------------------------------------------------===////
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===////
-
-#ifndef ATOMIC_SUPPORT_H
-#define ATOMIC_SUPPORT_H
-
-#include "__config"
-#include "memory" // for __libcpp_relaxed_load
-
-#if defined(__clang__) && __has_builtin(__atomic_load_n) \
- && __has_builtin(__atomic_store_n) \
- && __has_builtin(__atomic_add_fetch) \
- && __has_builtin(__atomic_compare_exchange_n) \
- && defined(__ATOMIC_RELAXED) \
- && defined(__ATOMIC_CONSUME) \
- && defined(__ATOMIC_ACQUIRE) \
- && defined(__ATOMIC_RELEASE) \
- && defined(__ATOMIC_ACQ_REL) \
- && defined(__ATOMIC_SEQ_CST)
-# define _LIBCPP_HAS_ATOMIC_BUILTINS
-#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
-# define _LIBCPP_HAS_ATOMIC_BUILTINS
-#endif
-
-#if !defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS)
-# if defined(_MSC_VER) && !defined(__clang__)
- _LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported")
-# else
-# warning Building libc++ without __atomic builtins is unsupported
-# endif
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-namespace {
-
-#if defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS)
-
-enum __libcpp_atomic_order {
- _AO_Relaxed = __ATOMIC_RELAXED,
- _AO_Consume = __ATOMIC_CONSUME,
- _AO_Acquire = __ATOMIC_ACQUIRE,
- _AO_Release = __ATOMIC_RELEASE,
- _AO_Acq_Rel = __ATOMIC_ACQ_REL,
- _AO_Seq = __ATOMIC_SEQ_CST
-};
-
-template <class _ValueType, class _FromType>
-inline _LIBCPP_INLINE_VISIBILITY
-void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
- int __order = _AO_Seq)
-{
- __atomic_store_n(__dest, __val, __order);
-}
-
-template <class _ValueType, class _FromType>
-inline _LIBCPP_INLINE_VISIBILITY
-void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
-{
- __atomic_store_n(__dest, __val, _AO_Relaxed);
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_ValueType __libcpp_atomic_load(_ValueType const* __val,
- int __order = _AO_Seq)
-{
- return __atomic_load_n(__val, __order);
-}
-
-template <class _ValueType, class _AddType>
-inline _LIBCPP_INLINE_VISIBILITY
-_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a,
- int __order = _AO_Seq)
-{
- return __atomic_add_fetch(__val, __a, __order);
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-bool __libcpp_atomic_compare_exchange(_ValueType* __val,
- _ValueType* __expected, _ValueType __after,
- int __success_order = _AO_Seq,
- int __fail_order = _AO_Seq)
-{
- return __atomic_compare_exchange_n(__val, __expected, __after, true,
- __success_order, __fail_order);
-}
-
-#else // _LIBCPP_HAS_NO_THREADS
-
-enum __libcpp_atomic_order {
- _AO_Relaxed,
- _AO_Consume,
- _AO_Acquire,
- _AO_Release,
- _AO_Acq_Rel,
- _AO_Seq
-};
-
-template <class _ValueType, class _FromType>
-inline _LIBCPP_INLINE_VISIBILITY
-void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
- int = 0)
-{
- *__dest = __val;
-}
-
-template <class _ValueType, class _FromType>
-inline _LIBCPP_INLINE_VISIBILITY
-void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
-{
- *__dest = __val;
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_ValueType __libcpp_atomic_load(_ValueType const* __val,
- int = 0)
-{
- return *__val;
-}
-
-template <class _ValueType, class _AddType>
-inline _LIBCPP_INLINE_VISIBILITY
-_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a,
- int = 0)
-{
- return *__val += __a;
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-bool __libcpp_atomic_compare_exchange(_ValueType* __val,
- _ValueType* __expected, _ValueType __after,
- int = 0, int = 0)
-{
- if (*__val == *__expected) {
- *__val = __after;
- return true;
- }
- *__expected = *__val;
- return false;
-}
-
-#endif // _LIBCPP_HAS_NO_THREADS
-
-} // end namespace
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // ATOMIC_SUPPORT_H
Index: libcxx/include/memory
===================================================================
--- libcxx/include/memory
+++ libcxx/include/memory
@@ -638,6 +638,8 @@
#include <stdexcept>
#include <cstring>
+#include <atomic_support.h>
+
#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
# include <atomic>
#endif
@@ -3788,12 +3790,34 @@
#endif // _LIBCPP_STD_VER > 14
+namespace
+{
+// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
+// should be sufficient for thread safety.
+// See https://llvm.org/bugs/show_bug.cgi?id=22803
+template <class T> __attribute__((always_inline))
+inline _LIBCPP_INLINE_VISIBILITY T
+increment(T& t) _NOEXCEPT
+{
+ return __libcpp_atomic_add(&t, 1, _AO_Relaxed);
+}
+
+template <class T> __attribute__((always_inline))
+inline _LIBCPP_INLINE_VISIBILITY T
+decrement(T& t) _NOEXCEPT
+{
+ return __libcpp_atomic_add(&t, -1, _AO_Acq_Rel);
+}
+} // namespace
+
class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
: public std::exception
{
public:
virtual ~bad_weak_ptr() _NOEXCEPT;
- virtual const char* what() const _NOEXCEPT;
+ virtual const char* what() const _NOEXCEPT {
+ return "bad_weak_ptr";
+ }
};
_LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE
@@ -3824,8 +3848,18 @@
explicit __shared_count(long __refs = 0) _NOEXCEPT
: __shared_owners_(__refs) {}
- void __add_shared() _NOEXCEPT;
- bool __release_shared() _NOEXCEPT;
+ inline _LIBCPP_INLINE_VISIBILITY
+ void __add_shared() _NOEXCEPT {
+ increment(__shared_owners_);
+ }
+ inline _LIBCPP_INLINE_VISIBILITY
+ bool __release_shared() _NOEXCEPT {
+ if (decrement(__shared_owners_) == -1) {
+ __on_zero_shared();
+ return true;
+ }
+ return false;
+ }
_LIBCPP_INLINE_VISIBILITY
long use_count() const _NOEXCEPT {
return __libcpp_relaxed_load(&__shared_owners_) + 1;
@@ -3846,9 +3880,19 @@
virtual ~__shared_weak_count();
public:
- void __add_shared() _NOEXCEPT;
- void __add_weak() _NOEXCEPT;
- void __release_shared() _NOEXCEPT;
+ inline _LIBCPP_INLINE_VISIBILITY
+ void __add_shared() _NOEXCEPT {
+ __shared_count::__add_shared();
+ }
+ inline _LIBCPP_INLINE_VISIBILITY
+ void __add_weak() _NOEXCEPT {
+ increment(__shared_weak_owners_);
+ }
+ inline _LIBCPP_INLINE_VISIBILITY
+ void __release_shared() _NOEXCEPT {
+ if (__shared_count::__release_shared())
+ __release_weak();
+ }
void __release_weak() _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY
long use_count() const _NOEXCEPT {return __shared_count::use_count();}
Index: libcxx/include/atomic_support.h
===================================================================
--- /dev/null
+++ libcxx/include/atomic_support.h
@@ -0,0 +1,157 @@
+//===----------------------------------------------------------------------===////
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===////
+
+#ifndef ATOMIC_SUPPORT_H
+#define ATOMIC_SUPPORT_H
+
+#include <__config>
+
+#if defined(__clang__) && __has_builtin(__atomic_load_n) \
+ && __has_builtin(__atomic_store_n) \
+ && __has_builtin(__atomic_add_fetch) \
+ && __has_builtin(__atomic_compare_exchange_n) \
+ && defined(__ATOMIC_RELAXED) \
+ && defined(__ATOMIC_CONSUME) \
+ && defined(__ATOMIC_ACQUIRE) \
+ && defined(__ATOMIC_RELEASE) \
+ && defined(__ATOMIC_ACQ_REL) \
+ && defined(__ATOMIC_SEQ_CST)
+# define _LIBCPP_HAS_ATOMIC_BUILTINS
+#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
+# define _LIBCPP_HAS_ATOMIC_BUILTINS
+#endif
+
+#if !defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS)
+# if defined(_MSC_VER) && !defined(__clang__)
+ _LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported")
+# else
+# warning Building libc++ without __atomic builtins is unsupported
+# endif
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace {
+
+#if defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS)
+
+enum __libcpp_atomic_order {
+ _AO_Relaxed = __ATOMIC_RELAXED,
+ _AO_Consume = __ATOMIC_CONSUME,
+ _AO_Acquire = __ATOMIC_ACQUIRE,
+ _AO_Release = __ATOMIC_RELEASE,
+ _AO_Acq_Rel = __ATOMIC_ACQ_REL,
+ _AO_Seq = __ATOMIC_SEQ_CST
+};
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
+ int __order = _AO_Seq)
+{
+ __atomic_store_n(__dest, __val, __order);
+}
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
+{
+ __atomic_store_n(__dest, __val, _AO_Relaxed);
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_load(_ValueType const* __val,
+ int __order = _AO_Seq)
+{
+ return __atomic_load_n(__val, __order);
+}
+
+template <class _ValueType, class _AddType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a,
+ int __order = _AO_Seq)
+{
+ return __atomic_add_fetch(__val, __a, __order);
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+bool __libcpp_atomic_compare_exchange(_ValueType* __val,
+ _ValueType* __expected, _ValueType __after,
+ int __success_order = _AO_Seq,
+ int __fail_order = _AO_Seq)
+{
+ return __atomic_compare_exchange_n(__val, __expected, __after, true,
+ __success_order, __fail_order);
+}
+
+#else // _LIBCPP_HAS_NO_THREADS
+
+enum __libcpp_atomic_order {
+ _AO_Relaxed,
+ _AO_Consume,
+ _AO_Acquire,
+ _AO_Release,
+ _AO_Acq_Rel,
+ _AO_Seq
+};
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
+ int = 0)
+{
+ *__dest = __val;
+}
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
+{
+ *__dest = __val;
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_load(_ValueType const* __val,
+ int = 0)
+{
+ return *__val;
+}
+
+template <class _ValueType, class _AddType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a,
+ int = 0)
+{
+ return *__val += __a;
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+bool __libcpp_atomic_compare_exchange(_ValueType* __val,
+ _ValueType* __expected, _ValueType __after,
+ int = 0, int = 0)
+{
+ if (*__val == *__expected) {
+ *__val = __after;
+ return true;
+ }
+ *__expected = *__val;
+ return false;
+}
+
+#endif // _LIBCPP_HAS_NO_THREADS
+
+} // end namespace
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // ATOMIC_SUPPORT_H
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