diff --git a/compiler-rt/cmake/base-config-ix.cmake b/compiler-rt/cmake/base-config-ix.cmake
--- a/compiler-rt/cmake/base-config-ix.cmake
+++ b/compiler-rt/cmake/base-config-ix.cmake
@@ -189,8 +189,12 @@
     elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "s390x")
       test_target_arch(s390x "" "")
     elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "sparc")
-      test_target_arch(sparc "" "-m32")
-      test_target_arch(sparcv9 "" "-m64")
+      if (CMAKE_SIZEOF_VOID_P EQUAL 4)
+        test_target_arch(sparc "" "-m32")
+        append("-latomic" CMAKE_LD_FLAGS)
+      else()
+        test_target_arch(sparcv9 "" "-m64")
+      endif()
     elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "mipsel|mips64el")
       # Gcc doesn't accept -m32/-m64 so we do the next best thing and use
       # -mips32r2/-mips64r2. We don't use -mips1/-mips3 because we want to match