diff --git a/configure b/configure
index 87278d73ea9..a90d4c1cccf 100755
--- a/configure
+++ b/configure
@@ -34902,6 +34902,96 @@ rm -f core conftest.err conftest.$ac_objext \
 
 
 
+if test "$llvm_cv_os_type" = "Linux" -a "$llvm_cv_target_arch" = "x86_64" ; then
+  { echo "$as_me:$LINENO: checking for 32-bit userspace on 64-bit system" >&5
+echo $ECHO_N "checking for 32-bit userspace on 64-bit system... $ECHO_C" >&6; }
+if test "${llvm_cv_linux_mixed+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+   ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#ifndef __x86_64__
+       error: Not x86-64 even if uname says so!
+      #endif
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  llvm_cv_linux_mixed=no
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	llvm_cv_linux_mixed=yes
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+fi
+{ echo "$as_me:$LINENO: result: $llvm_cv_linux_mixed" >&5
+echo "${ECHO_T}$llvm_cv_linux_mixed" >&6; }
+
+  if test "$llvm_cv_linux_mixed" = "yes"; then
+    llvm_cv_target_arch="x86"
+    ARCH="x86"
+  fi
+fi
+
 
 for ac_func in __dso_handle
 do