--- /clang/lib/Basic/CMakeLists.txt
+++ /clang/lib/Basic/CMakeLists.txt
@@ -110,3 +110,23 @@
   omp_gen
   )
 
+# libclangBasic compiled by GCC at least on 32-bit PowerPC may contain reference
+# to __atomic_load_8.
+# Link against library libatomic provided by GCC.
+if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  # Use options --push-state, --as-needed and --pop-state if linker is known
+  # to support them.
+  # Use single option -Wl of compiler driver to avoid incorrect re-ordering
+  # of options by CMake.
+  if (LLVM_LINKER_IS_GNULD OR LLVM_LINKER_IS_GOLD OR LLVM_LINKER_IS_LLD OR LLVM_LINKER_IS_MOLD)
+    target_link_libraries(clangBasic
+      PRIVATE
+      "-Wl,--push-state,--as-needed,-latomic,--pop-state"
+    )
+  else()
+    target_link_libraries(clangBasic
+      PRIVATE
+      atomic
+    )
+  endif()
+endif()