re PR fortran/62278 (gfc_check_dependency should also check for TARGET attribute)

2014-08-30  Tobias Burnus  <burnus@net-b.de>

        PR fortran/62278
        PR fortran/44735
        PR fortran/60593
        * dependency.c (gfc_check_dependency): Allow for optimizations
        in the pointer-alias check.

From-SVN: r214757

gcc/fortran/ChangeLog

+2014-08-30  Tobias Burnus  <burnus@net-b.de>
+
+	PR fortran/62278
+	PR fortran/44735
+	PR fortran/60593
+	* dependency.c (gfc_check_dependency): Allow for optimizations
+	in the pointer-alias check.
+
 2014-08-30  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	* module.c (gfc_dump_module): Use ISO C remove() instead of POSIX

gcc/fortran/dependency.c

@@ -1269,6 +1269,7 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical)
       /* The interesting cases are when the symbols don't match.  */
       if (expr1->symtree->n.sym != expr2->symtree->n.sym)
 	{
+	  symbol_attribute attr1, attr2;
 	  gfc_typespec *ts1 = &expr1->symtree->n.sym->ts;
 	  gfc_typespec *ts2 = &expr2->symtree->n.sym->ts;
 
@@ -1284,9 +1285,13 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical)
 		return 0;
 	    }
 
-	  /* If either variable is a pointer, assume the worst.  */
-	  /* TODO: -fassume-no-pointer-aliasing */
-	  if (gfc_is_data_pointer (expr1) || gfc_is_data_pointer (expr2))
+	  /* We have to also include target-target as ptr%comp is not a
+	     pointer but it still alias with "dt%comp" for "ptr => dt".  As
+	     subcomponents and array access to pointers retains the target
+	     attribute, that's sufficient.  */
+	  attr1 = gfc_expr_attr (expr1);
+	  attr2 = gfc_expr_attr (expr2);
+	  if ((attr1.pointer || attr1.target) && (attr2.pointer || attr2.target))
 	    {
 	      if (check_data_pointer_types (expr1, expr2)
 		    && check_data_pointer_types (expr2, expr1))