More refinements to fixing sparc's PR target/80968.

gcc/

	PR target/80968
	* config/sparc/sparc.md (return expander): Emit frame blockage if
	function uses alloca.

From-SVN: r249134

gcc/ChangeLog

+2017-06-12  David S. Miller  <davem@davemloft.net>
+
+	PR target/80968
+	* config/sparc/sparc.md (return expander): Emit frame blockage if
+	function uses alloca.
+
 2017-06-12  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	* combine.c (make_field_assignment): Check len rather than the mode

gcc/config/sparc/sparc.md

@@ -7098,7 +7098,10 @@
 (define_expand "return"
   [(return)]
   "sparc_can_use_return_insn_p ()"
-  "")
+{
+  if (cfun->calls_alloca)
+    emit_insn (gen_frame_blockage ());
+})
 
 (define_insn "*return_internal"
   [(return)]