re PR ipa/77653 (wrong code at -Os and above on x86_64-linux-gnu (in both 32-bit and 64-bit modes))

Fix PR ipa/77653

	PR ipa/77653
	* gcc.dg/ipa/pr77653.c: New test.
	PR ipa/77653
	* ipa-icf.c (sem_variable::merge): Yield merge operation if
	alias address matters, not necessarily address of original.

From-SVN: r240354

gcc/ChangeLog

+2016-09-22  Martin Liska  <mliska@suse.cz>
+
+	PR ipa/77653
+	* ipa-icf.c (sem_variable::merge): Yield merge operation if
+	alias address matters, not necessarily address of original.
+
 2016-09-22  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/77697

gcc/ipa-icf.c

@@ -2179,7 +2179,6 @@ sem_variable::merge (sem_item *alias_item)
   varpool_node *alias = alias_var->get_node ();
   bool original_discardable = false;
 
-  bool original_address_matters = original->address_matters_p ();
   bool alias_address_matters = alias->address_matters_p ();
 
   /* See if original is in a section that can be discarded if the main
@@ -2222,13 +2221,11 @@ sem_variable::merge (sem_item *alias_item)
     }
 
   /* We can not merge if address comparsion metters.  */
-  if (original_address_matters && alias_address_matters
-      && flag_merge_constants < 2)
+  if (alias_address_matters && flag_merge_constants < 2)
     {
       if (dump_file)
 	fprintf (dump_file,
-		 "Not unifying; "
-		 "adress of original and alias may be compared.\n\n");
+		 "Not unifying; adress of original may be compared.\n\n");
       return false;
     }
 

gcc/testsuite/ChangeLog

+2016-09-22  Martin Liska  <mliska@suse.cz>
+
+	PR ipa/77653
+	* gcc.dg/ipa/pr77653.c: New test.
+
 2016-09-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR fortran/77665

gcc/testsuite/gcc.dg/ipa/pr77653.c

+/* { dg-options "-O2 -fdump-ipa-icf-details"  } */
+
+int a, b, c, d, e, h, i, j, k, l;
+const int f;
+static int g;
+
+void fn1 (int p1)
+{
+  k = d ? c % k : a * b;
+  h &= j ^ i ^ 1;
+}
+
+int main ()
+{
+  const int *m = &f, **n = &m;
+  l && (*n = &e);
+  if (m != &f)
+    __builtin_abort ();
+  fn1 (g);
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump "Equal symbols: 1" "icf"  } } */
+/* { dg-final { scan-ipa-dump "Not unifying; adress of original may be compared." "icf"  } } */