diff --git a/include/boost/core/detail/sp_thread_pause.hpp b/include/boost/core/detail/sp_thread_pause.hpp
new file mode 100644
index 0000000..4301488
--- /dev/null
+++ b/include/boost/core/detail/sp_thread_pause.hpp
@@ -0,0 +1,51 @@
+#ifndef BOOST_CORE_DETAIL_SP_THREAD_PAUSE_HPP_INCLUDED
+#define BOOST_CORE_DETAIL_SP_THREAD_PAUSE_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+// boost/core/detail/sp_thread_pause.hpp
+//
+// inline void bost::core::sp_thread_pause();
+//
+//   Emits a "pause" instruction.
+//
+// Copyright 2008, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// https://www.boost.org/LICENSE_1_0.txt
+
+#if defined(_MSC_VER) && _MSC_VER >= 1310 && ( defined(_M_IX86) || defined(_M_X64) ) && !defined(__c2__)
+
+extern "C" void _mm_pause();
+
+#define BOOST_CORE_SP_PAUSE _mm_pause();
+
+#elif defined(__GNUC__) && ( defined(__i386__) || defined(__x86_64__) )
+
+#define BOOST_CORE_SP_PAUSE __asm__ __volatile__( "rep; nop" : : : "memory" );
+
+#else
+
+#define BOOST_CORE_SP_PAUSE
+
+#endif
+
+namespace boost
+{
+namespace core
+{
+
+inline void sp_thread_pause()
+{
+    BOOST_CORE_SP_PAUSE
+}
+
+} // namespace core
+} // namespace boost
+
+#undef BOOST_SP_PAUSE
+
+#endif // #ifndef BOOST_CORE_DETAIL_SP_THREAD_PAUSE_HPP_INCLUDED
diff --git a/include/boost/core/detail/sp_thread_sleep.hpp b/include/boost/core/detail/sp_thread_sleep.hpp
new file mode 100644
index 0000000..d18da23
--- /dev/null
+++ b/include/boost/core/detail/sp_thread_sleep.hpp
@@ -0,0 +1,104 @@
+#ifndef BOOST_CORE_DETAIL_SP_THREAD_SLEEP_HPP_INCLUDED
+#define BOOST_CORE_DETAIL_SP_THREAD_SLEEP_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+// boost/core/detail/sp_thread_sleep.hpp
+//
+// inline void bost::core::sp_thread_sleep();
+//
+//   Cease execution for a while to yield to other threads,
+//   as if by calling nanosleep() with an appropriate interval.
+//
+// Copyright 2008, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if defined( _WIN32 ) || defined( __WIN32__ ) || defined( __CYGWIN__ )
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+  BOOST_PRAGMA_MESSAGE("Using Sleep(1) in sp_thread_sleep")
+#endif
+
+#include <boost/core/detail/sp_win32_sleep.hpp>
+
+namespace boost
+{
+namespace core
+{
+namespace detail
+{
+
+inline void sp_thread_sleep()
+{
+    Sleep( 1 );
+}
+
+} // namespace detail
+
+using boost::core::detail::sp_thread_sleep;
+
+} // namespace core
+} // namespace boost
+
+#elif defined(BOOST_HAS_NANOSLEEP)
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+  BOOST_PRAGMA_MESSAGE("Using nanosleep() in sp_thread_sleep")
+#endif
+
+#include <time.h>
+
+namespace boost
+{
+namespace core
+{
+
+inline void sp_thread_sleep()
+{
+    // g++ -Wextra warns on {} or {0}
+    struct timespec rqtp = { 0, 0 };
+
+    // POSIX says that timespec has tv_sec and tv_nsec
+    // But it doesn't guarantee order or placement
+
+    rqtp.tv_sec = 0;
+    rqtp.tv_nsec = 1000;
+
+    nanosleep( &rqtp, 0 );
+}
+
+} // namespace core
+} // namespace boost
+
+#else
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+  BOOST_PRAGMA_MESSAGE("Using sp_thread_yield() in sp_thread_sleep")
+#endif
+
+#include <boost/core/detail/sp_thread_yield.hpp>
+
+namespace boost
+{
+namespace core
+{
+
+inline void sp_thread_sleep()
+{
+    sp_thread_yield();
+}
+
+} // namespace core
+} // namespace boost
+
+#endif
+
+#endif // #ifndef BOOST_CORE_DETAIL_SP_THREAD_SLEEP_HPP_INCLUDED
diff --git a/include/boost/core/detail/sp_thread_yield.hpp b/include/boost/core/detail/sp_thread_yield.hpp
new file mode 100644
index 0000000..c19e7e6
--- /dev/null
+++ b/include/boost/core/detail/sp_thread_yield.hpp
@@ -0,0 +1,100 @@
+#ifndef BOOST_CORE_DETAIL_SP_THREAD_YIELD_HPP_INCLUDED
+#define BOOST_CORE_DETAIL_SP_THREAD_YIELD_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+// boost/core/detail/sp_thread_yield.hpp
+//
+// inline void bost::core::sp_thread_yield();
+//
+//   Gives up the remainder of the time slice,
+//   as if by calling sched_yield().
+//
+// Copyright 2008, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if defined( _WIN32 ) || defined( __WIN32__ ) || defined( __CYGWIN__ )
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+  BOOST_PRAGMA_MESSAGE("Using Sleep(0) in sp_thread_yield")
+#endif
+
+#include <boost/core/detail/sp_win32_sleep.hpp>
+
+namespace boost
+{
+namespace core
+{
+namespace detail
+{
+
+inline void sp_thread_yield()
+{
+    Sleep( 0 );
+}
+
+} // namespace detail
+
+using boost::core::detail::sp_thread_yield;
+
+} // namespace core
+} // namespace boost
+
+#elif defined(BOOST_HAS_SCHED_YIELD)
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+  BOOST_PRAGMA_MESSAGE("Using sched_yield() in sp_thread_yield")
+#endif
+
+#ifndef _AIX
+# include <sched.h>
+#else
+  // AIX's sched.h defines ::var which sometimes conflicts with Lambda's var
+  extern "C" int sched_yield(void);
+#endif
+
+namespace boost
+{
+namespace core
+{
+
+inline void sp_thread_yield()
+{
+    sched_yield();
+}
+
+} // namespace core
+} // namespace boost
+
+#else
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+  BOOST_PRAGMA_MESSAGE("Using sp_thread_pause() in sp_thread_yield")
+#endif
+
+#include <boost/core/detail/sp_thread_pause.hpp>
+
+namespace boost
+{
+namespace core
+{
+
+inline void sp_thread_yield()
+{
+    sp_thread_pause();
+}
+
+} // namespace core
+} // namespace boost
+
+#endif
+
+#endif // #ifndef BOOST_CORE_DETAIL_SP_THREAD_YIELD_HPP_INCLUDED
diff --git a/include/boost/core/detail/sp_win32_sleep.hpp b/include/boost/core/detail/sp_win32_sleep.hpp
new file mode 100644
index 0000000..df51292
--- /dev/null
+++ b/include/boost/core/detail/sp_win32_sleep.hpp
@@ -0,0 +1,52 @@
+#ifndef BOOST_CORE_DETAIL_SP_WIN32_SLEEP_HPP_INCLUDED
+#define BOOST_CORE_DETAIL_SP_WIN32_SLEEP_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+// boost/core/detail/sp_win32_sleep.hpp
+//
+// Declares the Win32 Sleep() function.
+//
+// Copyright 2008, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// https://www.boost.org/LICENSE_1_0.txt
+
+#if defined( BOOST_USE_WINDOWS_H )
+# include <windows.h>
+#endif
+
+namespace boost
+{
+namespace core
+{
+namespace detail
+{
+
+#if !defined( BOOST_USE_WINDOWS_H )
+
+#if defined(__clang__) && defined(__x86_64__)
+// clang x64 warns that __stdcall is ignored
+# define BOOST_CORE_SP_STDCALL
+#else
+# define BOOST_CORE_SP_STDCALL __stdcall
+#endif
+
+#if defined(__LP64__) // Cygwin 64
+  extern "C" __declspec(dllimport) void BOOST_CORE_SP_STDCALL Sleep( unsigned int ms );
+#else
+  extern "C" __declspec(dllimport) void BOOST_CORE_SP_STDCALL Sleep( unsigned long ms );
+#endif
+
+#undef BOOST_CORE_SP_STDCALL
+
+#endif // !defined( BOOST_USE_WINDOWS_H )
+
+} // namespace detail
+} // namespace core
+} // namespace boost
+
+#endif // #ifndef BOOST_CORE_DETAIL_SP_WIN32_SLEEP_HPP_INCLUDED
diff --git a/include/boost/core/yield_primitives.hpp b/include/boost/core/yield_primitives.hpp
new file mode 100644
index 0000000..899453e
--- /dev/null
+++ b/include/boost/core/yield_primitives.hpp
@@ -0,0 +1,12 @@
+#ifndef BOOST_CORE_YIELD_PRIMITIVES_HPP_INCLUDED
+#define BOOST_CORE_YIELD_PRIMITIVES_HPP_INCLUDED
+
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/detail/sp_thread_pause.hpp>
+#include <boost/core/detail/sp_thread_yield.hpp>
+#include <boost/core/detail/sp_thread_sleep.hpp>
+
+#endif  // #ifndef BOOST_CORE_YIELD_PRIMITIVES_HPP_INCLUDED
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 5f79241..83d9d46 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -386,5 +386,10 @@ run serialization_construct_data_test.cpp : : : <library>/boost//serialization/<
 run identity_test.cpp ;
 run identity_rvalue_test.cpp ;
 
+run sp_thread_pause_test.cpp ;
+run sp_thread_yield_test.cpp ;
+run sp_thread_sleep_test.cpp ;
+run yield_prim_windows_h_test.cpp ;
+
 use-project /boost/core/swap : ./swap ;
 build-project ./swap ;
diff --git a/test/sp_thread_pause_test.cpp b/test/sp_thread_pause_test.cpp
new file mode 100644
index 0000000..1bbd0c0
--- /dev/null
+++ b/test/sp_thread_pause_test.cpp
@@ -0,0 +1,15 @@
+// Test for sp_thread_pause
+//
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/yield_primitives.hpp>
+
+int main()
+{
+    for( int i = 0; i < 1048576; ++i )
+    {
+        boost::core::sp_thread_pause();
+    }
+}
diff --git a/test/sp_thread_sleep_test.cpp b/test/sp_thread_sleep_test.cpp
new file mode 100644
index 0000000..2ee84ed
--- /dev/null
+++ b/test/sp_thread_sleep_test.cpp
@@ -0,0 +1,15 @@
+// Test for sp_thread_sleep
+//
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/yield_primitives.hpp>
+
+int main()
+{
+    for( int i = 0; i < 1000; ++i )
+    {
+        boost::core::sp_thread_sleep();
+    }
+}
diff --git a/test/sp_thread_yield_test.cpp b/test/sp_thread_yield_test.cpp
new file mode 100644
index 0000000..81d3f70
--- /dev/null
+++ b/test/sp_thread_yield_test.cpp
@@ -0,0 +1,15 @@
+// Test for sp_thread_yield
+//
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/yield_primitives.hpp>
+
+int main()
+{
+    for( int i = 0; i < 10000; ++i )
+    {
+        boost::core::sp_thread_yield();
+    }
+}
diff --git a/test/yield_prim_windows_h_test.cpp b/test/yield_prim_windows_h_test.cpp
new file mode 100644
index 0000000..50f841f
--- /dev/null
+++ b/test/yield_prim_windows_h_test.cpp
@@ -0,0 +1,18 @@
+// Test for sp_thread_yield
+//
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#if defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+# include <windows.h>
+#endif
+
+#include <boost/core/yield_primitives.hpp>
+
+int main()
+{
+    boost::core::sp_thread_pause();
+    boost::core::sp_thread_yield();
+    boost::core::sp_thread_sleep();
+}