diff --git a/clang/lib/Driver/ToolChains/CommonArgs.h b/clang/lib/Driver/ToolChains/CommonArgs.h
--- a/clang/lib/Driver/ToolChains/CommonArgs.h
+++ b/clang/lib/Driver/ToolChains/CommonArgs.h
@@ -114,6 +114,8 @@
                       bool ForceStaticHostRuntime = false,
                       bool IsOffloadingHost = false, bool GompNeedsRT = false);
 
+const char *getAsNeededOption(const ToolChain &TC, bool as_needed);
+
 llvm::opt::Arg *getLastProfileUseArg(const llvm::opt::ArgList &Args);
 llvm::opt::Arg *getLastProfileSampleUseArg(const llvm::opt::ArgList &Args);
 
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -737,7 +737,7 @@
   return false;
 }
 
-static const char *getAsNeededOption(const ToolChain &TC, bool as_needed) {
+const char *tools::getAsNeededOption(const ToolChain &TC, bool as_needed) {
   assert(!TC.getTriple().isOSAIX() &&
          "AIX linker does not support any form of --as-needed option yet.");
 
diff --git a/clang/lib/Driver/ToolChains/Solaris.cpp b/clang/lib/Driver/ToolChains/Solaris.cpp
--- a/clang/lib/Driver/ToolChains/Solaris.cpp
+++ b/clang/lib/Driver/ToolChains/Solaris.cpp
@@ -132,6 +132,13 @@
       CmdArgs.push_back("-lssp_nonshared");
       CmdArgs.push_back("-lssp");
     }
+    // LLVM lacks atomics support on 32-bit SPARC, so forcibly link with
+    // libatomic as a workaround.
+    if (getToolChain().getTriple().getArch() == llvm::Triple::sparc) {
+      CmdArgs.push_back(getAsNeededOption(getToolChain(), true));
+      CmdArgs.push_back("-latomic");
+      CmdArgs.push_back(getAsNeededOption(getToolChain(), false));
+    }
     CmdArgs.push_back("-lgcc_s");
     CmdArgs.push_back("-lc");
     if (!Args.hasArg(options::OPT_shared)) {