re PR ipa/68790 (gcc.c-torture/execute/20050713-1.c FAILs with -O0 -fipa-icf)

Fix PR ipa/68790

	PR ipa/68790
	* ipa-icf.c (sem_function::param_used_p): Return true
	if ipa_node_params_sum equals to NULL.
	* gcc.dg/ipa/pr68790.c: New test.

From-SVN: r231446

gcc/ChangeLog

+2015-12-09  Martin Liska  <mliska@suse.cz>
+
+	PR ipa/68790
+	* ipa-icf.c (sem_function::param_used_p): Return true
+	if ipa_node_params_sum equals to NULL.
+
 2015-12-09  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/68583

gcc/ipa-icf.c

@@ -544,7 +544,7 @@ bool
 sem_function::param_used_p (unsigned int i)
 {
   if (ipa_node_params_sum == NULL)
-    return false;
+    return true;
 
   struct ipa_node_params *parms_info = IPA_NODE_REF (get_node ());
 

gcc/testsuite/ChangeLog

+2015-12-09  Martin Liska  <mliska@suse.cz>
+
+	* gcc.dg/ipa/pr68790.c: New test.
+
 2015-12-08  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR ipa/61886

gcc/testsuite/gcc.dg/ipa/pr68790.c

+/* { dg-do run } */
+/* { dg-options "-O0 -fipa-icf -fdump-ipa-icf"  } */
+
+struct S
+{
+  int a;
+};
+
+int
+foo3 (struct S x, struct S y, struct S z)
+{
+  if (z.a != 9)
+    __builtin_abort ();
+  return 0;
+}
+
+int
+bar3 (struct S x, struct S y, struct S z)
+{
+  return foo3 (y, x, z);
+}
+
+int
+baz3 (struct S x, struct S y, struct S z)
+{
+  return foo3 (y, z, x);
+}
+
+int
+main (void)
+{
+  struct S
+    a = { 3 },
+    b = { 6 },
+    c = { 9 };
+
+  return bar3 (b, a, c);
+}
+
+/* { dg-final { scan-ipa-dump "Equal symbols: 0" "icf"  } } */