diff --git a/compiler-rt/cmake/Modules/CompilerRTAIXUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTAIXUtils.cmake
new file mode 100644
--- /dev/null
+++ b/compiler-rt/cmake/Modules/CompilerRTAIXUtils.cmake
@@ -0,0 +1,106 @@
+include(CMakeParseArguments)
+include(CompilerRTUtils)
+
+set(AIX_LIBATOMIC_EXPORTED_ROUTINES
+  __atomic_compare_exchange
+  __atomic_compare_exchange_1
+  __atomic_compare_exchange_2
+  __atomic_compare_exchange_4
+  __atomic_compare_exchange_8
+  __atomic_exchange
+  __atomic_exchange_1
+  __atomic_exchange_2
+  __atomic_exchange_4
+  __atomic_exchange_8
+  __atomic_fetch_add_1
+  __atomic_fetch_add_2
+  __atomic_fetch_add_4
+  __atomic_fetch_add_8
+  __atomic_fetch_and_1
+  __atomic_fetch_and_2
+  __atomic_fetch_and_4
+  __atomic_fetch_and_8
+  __atomic_fetch_or_1
+  __atomic_fetch_or_2
+  __atomic_fetch_or_4
+  __atomic_fetch_or_8
+  __atomic_fetch_sub_1
+  __atomic_fetch_sub_2
+  __atomic_fetch_sub_4
+  __atomic_fetch_sub_8
+  __atomic_fetch_xor_1
+  __atomic_fetch_xor_2
+  __atomic_fetch_xor_4
+  __atomic_fetch_xor_8
+  __atomic_is_lock_free
+  __atomic_load
+  __atomic_load_1
+  __atomic_load_2
+  __atomic_load_4
+  __atomic_load_8
+  __atomic_store
+  __atomic_store_1
+  __atomic_store_2
+  __atomic_store_4
+  __atomic_store_8
+)
+
+function(generate_aix_libatomic_export_list export_list)
+  # Write exported routines to export list file prior the build.
+  STRING(REGEX REPLACE ";" "\n" AIX_LIBATOMIC_EXPORTED_ROUTINES_TEXT
+    "${AIX_LIBATOMIC_EXPORTED_ROUTINES}")
+  file(GENERATE
+       OUTPUT ${export_list}
+       CONTENT ${AIX_LIBATOMIC_EXPORTED_ROUTINES_TEXT})
+endfunction()
+
+function(get_aix_libatomic_default_link_flags link_flags export_list)
+  set(${link_flags}
+    "-Wl,-b${bitmode} -Wl,-H512 -Wl,-D0 \
+     -Wl,-T512 -Wl,-bhalt:4 -Wl,-bernotok \
+     -Wl,-bnoentry -Wl,-bexport:${export_list} \
+     -Wl,-bmodtype:SRE -Wl,-lc")
+endfunction()
+
+macro(archive_aix_libatomic name)
+  cmake_parse_arguments(LIB
+    ""
+    ""
+    "ARCHS;PARENT_TARGET"
+    ${ARGN})
+  set(built_shared_libatomic "")
+  set(shared_libraries_to_archive "")
+  foreach (arch ${LIB_ARCHS})
+    if(CAN_TARGET_${arch})
+      set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/libatomic-${arch}.dir")
+      # FIXME: Target name should be kept consistent with definition
+      # in AddCompilerRT.cmake.
+      set(target ${name}-dynamic-${arch})
+      if(TARGET ${target})
+        file(MAKE_DIRECTORY ${output_dir})
+        add_custom_command(TARGET ${target}
+                           POST_BUILD
+                           COMMAND ${CMAKE_COMMAND} -E
+                           copy "$<TARGET_FILE:${target}>"
+                                "${output_dir}/libatomic.so.1")
+        list(APPEND built_shared_libatomic ${target})
+        list(APPEND shared_libraries_to_archive "${output_dir}/libatomic.so.1")
+      endif()
+    endif()
+  endforeach()
+  if(built_shared_libatomic)
+    set(output_dir "")
+    set(install_dir "")
+    get_compiler_rt_output_dir(${COMPILER_RT_DEFAULT_TARGET_ARCH} output_dir)
+    get_compiler_rt_install_dir(${COMPILER_RT_DEFAULT_TARGET_ARCH} install_dir)
+    add_custom_command(OUTPUT "${output_dir}/libatomic.a"
+                       COMMAND ${CMAKE_AR} -X32_64 r "${output_dir}/libatomic.a"
+                       ${shared_libraries_to_archive}
+                       DEPENDS ${built_shared_libatomic})
+    install(FILES "${output_dir}/libatomic.a"
+            DESTINATION ${install_dir})
+    add_custom_target(aix-libatomic
+                      DEPENDS "${output_dir}/libatomic.a")
+  endif()
+  add_dependencies(${LIB_PARENT_TARGET} aix-libatomic)
+endmacro()
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -48,6 +48,10 @@
 
 include(builtin-config-ix)
 
+if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+  include(CompilerRTAIXUtils)
+endif()
+
 option(COMPILER_RT_BUILTINS_HIDE_SYMBOLS
   "Do not export any symbols from the static library." ON)
 
@@ -747,4 +751,43 @@
   endforeach ()
 endif ()
 
+option(COMPILER_RT_BUILD_STANDALONE_LIBATOMIC
+  "Build standalone shared atomic library."
+  OFF)
+
+if(COMPILER_RT_BUILD_STANDALONE_LIBATOMIC)
+  add_custom_target(builtins-standalone-atomic)
+  set(BUILTIN_LINK_FLAGS "")
+  if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+    if(NOT AIX_LIBATOMIC_LINK_FLAGS)
+      # On AIX, before building the library, an export list must be provided.
+      set(AIX_LIBATOMIC_EXPORT_LIST
+        ${CMAKE_CURRENT_BINARY_DIR}/export_list.atomic)
+      generate_aix_libatomic_export_list(${AIX_LIBATOMIC_EXPORT_LIST})
+      get_aix_libatomic_default_link_flags(BUILTIN_LINK_FLAGS ${AIX_LIBATOMIC_EXPORT_LIST})
+    else()
+      set(${BUILTIN_LINK_FLAGS} ${AIX_LIBATOMIC_LINK_FLAGS})
+    endif()
+  endif()
+  foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+    if(CAN_TARGET_${arch})
+      add_compiler_rt_runtime(clang_rt.atomic
+                              SHARED
+                              ARCHS ${arch}
+                              SOURCES atomic.c
+                              LINK_FLAGS ${BUILTIN_LINK_FLAGS}
+                              PARENT_TARGET builtins-standalone-atomic)
+    endif()
+  endforeach()
+  # FIXME: On AIX, we have to archive built shared libraries into a static
+  # archive, i.e., libatomic.a. Once cmake adds support of such usage for AIX,
+  # this ad-hoc part can be removed.
+  if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+    archive_aix_libatomic(clang_rt.atomic
+                          ARCHS ${BUILTIN_SUPPORTED_ARCH}
+                          PARENT_TARGET builtins-standalone-atomic)
+  endif()
+  add_dependencies(builtins builtins-standalone-atomic)
+endif()
+
 add_dependencies(compiler-rt builtins)