* calls.c (load_register_parameters): Fix zero size sibcall logic.

From-SVN: r234332

gcc/ChangeLog

+2016-03-18  Jason Merrill  <jason@redhat.com>
+
+	* calls.c (load_register_parameters): Fix zero size sibcall logic.
+
 2016-03-18  Kirill Yukhin  <kirill.yukhin@intel.com>
 
         * config/i386/sse.md: Use vpbroadcastq for broadcasting DF

gcc/calls.c

@@ -2083,9 +2083,9 @@ load_register_parameters (struct arg_data *args, int num_actuals,
 	      /* Check for overlap with already clobbered argument area,
 	         providing that this has non-zero size.  */
 	      if (is_sibcall
-		  && (size == 0
-		      || mem_overlaps_already_clobbered_arg_p 
-					   (XEXP (args[i].value, 0), size)))
+		  && size != 0
+		  && (mem_overlaps_already_clobbered_arg_p
+		      (XEXP (args[i].value, 0), size)))
 		*sibcall_failure = 1;
 
 	      if (size % UNITS_PER_WORD == 0

gcc/testsuite/gcc.dg/sibcall-11.c

+// Test for sibcall optimization with empty struct.
+// { dg-options "-O2" }
+// { dg-final { scan-assembler "jmp" { target i?86-*-* x86_64-*-* } } }
+
+struct A { };
+void f(struct A);
+void g(struct A a) { f(a); }