diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -631,6 +631,14 @@
 
       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
 
+      // LLVM support for atomics on 32-bit SPARC V8+ is incomplete, so
+      // forcibly link with libatomic as a workaround.
+      if (getToolChain().getTriple().getArch() == llvm::Triple::sparc) {
+        CmdArgs.push_back("--as-needed");
+        CmdArgs.push_back("-latomic");
+        CmdArgs.push_back("--no-as-needed");
+      }
+
       if (WantPthread && !isAndroid)
         CmdArgs.push_back("-lpthread");