The change to pointer and function type hashing has made hashing
a lot weaker (contrary to what I expected) because if either type
resides in a SCC then we do _not_ take the hash of the visited
target types into account (I'm currently trying to think about
a way around that), so we are effectively weakening the hashes
by not hasing the target aggregate name.
Committed to trunk.
Richard.
2011-05-13 Richard Guenther <rguent...@suse.de>
PR lto/48978
* gimple.c (iterative_hash_gimple_type): Revert change in
pointer target and function result and argument hashing.
Index: gcc/gimple.c
===================================================================
--- gcc/gimple.c (revision 173725)
+++ gcc/gimple.c (working copy)
@@ -4110,10 +4110,20 @@ iterative_hash_gimple_type (tree type, h
}
/* For pointer and reference types, fold in information about the type
- pointed to. */
+ pointed to but do not recurse into possibly incomplete types to
+ avoid hash differences for complete vs. incomplete types. */
if (POINTER_TYPE_P (type))
- v = visit (TREE_TYPE (type), state, v,
- sccstack, sccstate, sccstate_obstack);
+ {
+ if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (type)))
+ {
+ v = iterative_hash_hashval_t (TREE_CODE (TREE_TYPE (type)), v);
+ v = iterative_hash_name
+ (TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (type))), v);
+ }
+ else
+ v = visit (TREE_TYPE (type), state, v,
+ sccstack, sccstate, sccstate_obstack);
+ }
/* For integer types hash the types min/max values and the string flag. */
if (TREE_CODE (type) == INTEGER_TYPE)
@@ -4154,13 +4164,29 @@ iterative_hash_gimple_type (tree type, h
v = visit (TYPE_METHOD_BASETYPE (type), state, v,
sccstack, sccstate, sccstate_obstack);
- /* Check result and argument types. */
- v = visit (TREE_TYPE (type), state, v,
- sccstack, sccstate, sccstate_obstack);
+ /* For result types allow mismatch in completeness. */
+ if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (type)))
+ {
+ v = iterative_hash_hashval_t (TREE_CODE (TREE_TYPE (type)), v);
+ v = iterative_hash_name
+ (TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (type))), v);
+ }
+ else
+ v = visit (TREE_TYPE (type), state, v,
+ sccstack, sccstate, sccstate_obstack);
+
for (p = TYPE_ARG_TYPES (type), na = 0; p; p = TREE_CHAIN (p))
{
- v = visit (TREE_VALUE (p), state, v,
- sccstack, sccstate, sccstate_obstack);
+ /* For argument types allow mismatch in completeness. */
+ if (RECORD_OR_UNION_TYPE_P (TREE_VALUE (p)))
+ {
+ v = iterative_hash_hashval_t (TREE_CODE (TREE_VALUE (p)), v);
+ v = iterative_hash_name
+ (TYPE_NAME (TYPE_MAIN_VARIANT (TREE_VALUE (p))), v);
+ }
+ else
+ v = visit (TREE_VALUE (p), state, v,
+ sccstack, sccstate, sccstate_obstack);
na++;
}
