2008-06-07 Jerry DeLisle <jvdelisle@gcc.gnu.org>

[pf3gnuchains/gcc-fork.git] / gcc / alias.c

diff --git a/gcc/alias.c b/gcc/alias.c
index 6bf67f3..06ad867 100644 (file)
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -133,6 +133,10 @@ struct alias_set_entry GTY(())
   /* The alias set number, as stored in MEM_ALIAS_SET.  */
   alias_set_type alias_set;
 
+  /* Nonzero if would have a child of zero: this effectively makes this
+     alias set the same as alias set zero.  */
+  int has_zero_child;
+
   /* The children of the alias set.  These are not just the immediate
      children, but, in fact, all descendants.  So, if we have:
 
@@ -141,10 +145,6 @@ struct alias_set_entry GTY(())
      continuing our example above, the children here will be all of
      `int', `double', `float', and `struct S'.  */
   splay_tree GTY((param1_is (int), param2_is (int))) children;
-
-  /* Nonzero if would have a child of zero: this effectively makes this
-     alias set the same as alias set zero.  */
-  int has_zero_child;
 };
 typedef struct alias_set_entry *alias_set_entry;
 
@@ -164,7 +164,6 @@ static int aliases_everything_p (const_rtx);
 static bool nonoverlapping_component_refs_p (const_tree, const_tree);
 static tree decl_for_component_ref (tree);
 static rtx adjust_offset_for_component_ref (tree, rtx);
-static int nonoverlapping_memrefs_p (const_rtx, const_rtx);
 static int write_dependence_p (const_rtx, const_rtx, int);
 
 static void memory_modified_1 (rtx, const_rtx, void *);
@@ -306,8 +305,9 @@ alias_set_subset_of (alias_set_type set1, alias_set_type set2)
   /* Otherwise, check if set1 is a subset of set2.  */
   ase = get_alias_set_entry (set2);
   if (ase != 0
-      && (splay_tree_lookup (ase->children,
-                            (splay_tree_key) set1)))
+      && ((ase->has_zero_child && set1 == 0)
+         || splay_tree_lookup (ase->children,
+                               (splay_tree_key) set1)))
     return true;
   return false;
 }
@@ -525,7 +525,12 @@ get_alias_set (tree t)
       /* Check for accesses through restrict-qualified pointers.  */
       if (INDIRECT_REF_P (inner))
        {
-         tree decl = find_base_decl (TREE_OPERAND (inner, 0));
+         tree decl;
+
+         if (TREE_CODE (TREE_OPERAND (inner, 0)) == SSA_NAME)
+           decl = SSA_NAME_VAR (TREE_OPERAND (inner, 0));
+         else
+           decl = find_base_decl (TREE_OPERAND (inner, 0));
 
          if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
            {
@@ -579,13 +584,6 @@ get_alias_set (tree t)
            return 0;
        }
 
-      /* For non-addressable fields we return the alias set of the
-        outermost object that could have its address taken.  If this
-        is an SFT use the precomputed value.  */
-      if (TREE_CODE (t) == STRUCT_FIELD_TAG
-         && SFT_NONADDRESSABLE_P (t))
-       return SFT_ALIAS_SET (t);
-
       /* Otherwise, pick up the outermost object that we could have a pointer
         to, processing conversions as above.  */
       while (component_uses_parent_alias_set (t))
@@ -735,9 +733,8 @@ record_alias_subset (alias_set_type superset, alias_set_type subset)
 
 /* Record that component types of TYPE, if any, are part of that type for
    aliasing purposes.  For record types, we only record component types
-   for fields that are marked addressable.  For array types, we always
-   record the component types, so the front end should not call this
-   function if the individual component aren't addressable.  */
+   for fields that are not marked non-addressable.  For array types, we
+   only record the component type if it is not marked non-aliased.  */
 
 void
 record_component_aliases (tree type)
@@ -751,7 +748,7 @@ record_component_aliases (tree type)
   switch (TREE_CODE (type))
     {
     case ARRAY_TYPE:
-      if (! TYPE_NONALIASED_COMPONENT (type))
+      if (!TYPE_NONALIASED_COMPONENT (type))
        record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
       break;
 
@@ -770,7 +767,7 @@ record_component_aliases (tree type)
                                 get_alias_set (BINFO_TYPE (base_binfo)));
        }
       for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
-       if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field))
+       if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field))
          record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
       break;
 
@@ -1971,7 +1968,7 @@ adjust_offset_for_component_ref (tree x, rtx offset)
 /* Return nonzero if we can determine the exprs corresponding to memrefs
    X and Y and they do not overlap.  */
 
-static int
+int
 nonoverlapping_memrefs_p (const_rtx x, const_rtx y)
 {
   tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);