2011-05-24 Richard Guenther <rguenther@suse.de>

	PR bootstrap/49078
	* gimple.c (gimple_register_canonical_type): Revert
	previous change.
	* alias.c (get_alias_set): Only assert that TYPE_CANONICAL
	does not for a tree for the case where it matters.  Cache
	pointer-type alias-sets.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@174113 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 6 insertions, 20 deletions

diff --git a/gcc/gimple.c b/gcc/gimple.c
index d6c79aa1f5c..4c0e4a387df 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -4779,7 +4779,12 @@ gimple_canonical_type_eq (const void *p1, const void *p2)
 /* Register type T in the global type table gimple_types.
    If another type T', compatible with T, already existed in
    gimple_types then return T', otherwise return T.  This is used by
-   LTO to merge identical types read from different TUs.  */
+   LTO to merge identical types read from different TUs.
+
+   ???  This merging does not exactly match how the tree.c middle-end
+   functions will assign TYPE_CANONICAL when new types are created
+   during optimization (which at least happens for pointer and array
+   types).  */
 
 tree
 gimple_register_canonical_type (tree t)
@@ -4800,25 +4805,6 @@ gimple_register_canonical_type (tree t)
   if (TYPE_CANONICAL (t))
     return TYPE_CANONICAL (t);
 
-  /* For pointer and reference types do as the middle-end does - the
-     canonical type is a pointer to the canonical pointed-to type.  */
-  if (TREE_CODE (t) == POINTER_TYPE)
-    {
-      TYPE_CANONICAL (t)
-	  = build_pointer_type_for_mode
-	  (gimple_register_canonical_type (TREE_TYPE (t)),
-	   TYPE_MODE (t), TYPE_REF_CAN_ALIAS_ALL (t));
-      return TYPE_CANONICAL (t);
-    }
-  else if (TREE_CODE (t) == REFERENCE_TYPE)
-    {
-      TYPE_CANONICAL (t)
-	  = build_reference_type_for_mode
-	  (gimple_register_canonical_type (TREE_TYPE (t)),
-	   TYPE_MODE (t), TYPE_REF_CAN_ALIAS_ALL (t));
-      return TYPE_CANONICAL (t);
-    }
-
   if (gimple_canonical_types == NULL)
     gimple_canonical_types = htab_create_ggc (16381, gimple_canonical_type_hash,
 					      gimple_canonical_type_eq, 0);