re PR target/16819 (ICE with empty struct as arg)

gcc/ChangeLog:
PR target/16819
* calls.c (load_register_parameters): Don't call use_regs when
nregs is zero.
gcc/testsuite/ChangeLog:
PR target/16891
* gcc.dg/empty2.c: New.

From-SVN: r92551

gcc/ChangeLog

+2004-12-23  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR target/16819
+	* calls.c (load_register_parameters): Don't call use_regs when
+	nregs is zero.
+
 2004-12-23  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
 	PR middle-end/17746

gcc/calls.c

@@ -1554,8 +1554,8 @@ load_register_parameters (struct arg_data *args, int num_actuals,
 	    use_group_regs (call_fusage, reg);
 	  else if (nregs == -1)
 	    use_reg (call_fusage, reg);
-	  else
-	    use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
+	  else if (nregs > 0)
+	    use_regs (call_fusage, REGNO (reg), nregs);
 	}
     }
 }

gcc/testsuite/ChangeLog

+2004-12-23  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR target/16891
+	* gcc.dg/empty2.c: New.
+
 2004-12-23  Richard Henderson  <rth@redhat.com>
 
 	* lib/target-supports.exp (check_effective_target_vect_no_align): 

gcc/testsuite/gcc.dg/empty2.c

+/* { dg-do compile } */
+
+double d=0;
+
+struct A {} a;
+
+void foo(struct A x)
+{
+  d=0;
+}
+
+void bar()
+{
+  if (d) foo(a);
+}