[Bug tree-optimization/29964] [4.1/4.2/4.3 Regression] function with volatile operators still found to be pure

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-11-23 22:49 -------
By the way this is the patch which I am testing:
Index: ipa-pure-const.c
===================================================================
--- ipa-pure-const.c    (revision 119134)
+++ ipa-pure-const.c    (working copy)
@@ -166,6 +166,14 @@ check_tree (funct_state local, tree t, b
   if ((TREE_CODE (t) == EXC_PTR_EXPR) || (TREE_CODE (t) == FILTER_EXPR))
     return;

+  /* Any tree which is volatile disqualifies this function from being
+     const or pure. */
+  if (TREE_THIS_VOLATILE (t))
+    {
+      local->pure_const_state = IPA_NEITHER;
+      return;
+    }
+
   while (TREE_CODE (t) == REALPART_EXPR
         || TREE_CODE (t) == IMAGPART_EXPR
         || handled_component_p (t))
@@ -183,12 +191,13 @@ check_tree (funct_state local, tree t, b

       /* Any indirect reference that occurs on the lhs
         disqualifies the function from being pure or const. Any
-        indirect reference to a volatile disqualifies the
-        function from being pure or const.  Any indirect
-        reference that occurs on the rhs disqualifies the
+        indirect reference that occurs on the rhs disqualifies the
         function from being const.  */
-      if (checking_write || TREE_THIS_VOLATILE (t))
-       local->pure_const_state = IPA_NEITHER;
+      if (checking_write)
+       {
+         local->pure_const_state = IPA_NEITHER;
+         return;
+       }
       else if (local->pure_const_state == IPA_CONST)
        local->pure_const_state = IPA_PURE;
     }
@@ -541,7 +550,7 @@ analyze_function (struct cgraph_node *fn
              walk_tree (bsi_stmt_ptr (bsi), scan_function,
                         fn, visited_nodes);
              if (l->pure_const_state == IPA_NEITHER)
-               return;
+               goto end;
            }
        }

@@ -568,6 +577,14 @@ analyze_function (struct cgraph_node *fn
          pop_cfun ();
        }
     }
+
+end:
+  if (dump_file)
+    {
+      fprintf (dump_file, "after local analysis of %s with initial value =
%d\n ",
+              cgraph_node_name (fn),
+              l->pure_const_state);
+    }
 }


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29964