Hi,
this patch disables the streaming of alias 0 flag and adds a comment why.
Bootstrapped/regtested x86_64-linux, OK?
Honza
* lto-streamer-out.c (hash_tree): Do not stream TYPE_ALIAS_SET.
* tree-streamer-out.c (pack_ts_type_common_value_fields): Do not
stream TYPE_ALIAS_SET.
* tree-streamer-in.c (unpack_ts_type_common_value_fields): Do not
stream TYPE_ALIAS_SET.
* lto.c (compare_tree_sccs_1): Do not compare TYPE_ALIAS_SET.
Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c (revision 231081)
+++ lto-streamer-out.c (working copy)
@@ -1109,10 +1109,6 @@ hash_tree (struct streamer_tree_cache_d
hstate.commit_flag ();
hstate.add_int (TYPE_PRECISION (t));
hstate.add_int (TYPE_ALIGN (t));
- hstate.add_int ((TYPE_ALIAS_SET (t) == 0
- || (!in_lto_p
- && get_alias_set (t) == 0))
- ? 0 : -1);
}
if (CODE_CONTAINS_STRUCT (code, TS_TRANSLATION_UNIT_DECL))
Index: lto/lto.c
===================================================================
--- lto/lto.c (revision 231081)
+++ lto/lto.c (working copy)
@@ -1166,7 +1166,9 @@ compare_tree_sccs_1 (tree t1, tree t2, t
compare_values (TYPE_READONLY);
compare_values (TYPE_PRECISION);
compare_values (TYPE_ALIGN);
- compare_values (TYPE_ALIAS_SET);
+ /* Do not compare TYPE_ALIAS_SET. Doing so introduce ordering issues
+ with calls to get_alias_set which may initialize it for streamed
+ in types. */
}
/* We don't want to compare locations, so there is nothing do compare
Index: tree-streamer-out.c
===================================================================
--- tree-streamer-out.c (revision 231081)
+++ tree-streamer-out.c (working copy)
@@ -317,13 +317,9 @@ pack_ts_type_common_value_fields (struct
bp_pack_value (bp, TYPE_RESTRICT (expr), 1);
bp_pack_value (bp, TYPE_USER_ALIGN (expr), 1);
bp_pack_value (bp, TYPE_READONLY (expr), 1);
- /* Make sure to preserve the fact whether the frontend would assign
- alias-set zero to this type. Do that only for main variants, because
- type variants alias sets are never computed.
- FIXME: This does not work for pre-streamed builtin types. */
- bp_pack_value (bp, (TYPE_ALIAS_SET (expr) == 0
- || (!in_lto_p && TYPE_MAIN_VARIANT (expr) == expr
- && get_alias_set (expr) == 0)), 1);
+ /* We used to stream TYPE_ALIAS_SET == 0 information to let frontends mark
+ types that are opaque for TBAA. This however did not work as intended,
+ becuase TYPE_ALIAS_SET == 0 was regularly lost in canonical type merging.
*/
if (RECORD_OR_UNION_TYPE_P (expr))
{
bp_pack_value (bp, TYPE_TRANSPARENT_AGGR (expr), 1);
Index: tree-streamer-in.c
===================================================================
--- tree-streamer-in.c (revision 231081)
+++ tree-streamer-in.c (working copy)
@@ -366,7 +366,6 @@ unpack_ts_type_common_value_fields (stru
TYPE_RESTRICT (expr) = (unsigned) bp_unpack_value (bp, 1);
TYPE_USER_ALIGN (expr) = (unsigned) bp_unpack_value (bp, 1);
TYPE_READONLY (expr) = (unsigned) bp_unpack_value (bp, 1);
- TYPE_ALIAS_SET (expr) = bp_unpack_value (bp, 1) ? 0 : -1;
if (RECORD_OR_UNION_TYPE_P (expr))
{
TYPE_TRANSPARENT_AGGR (expr) = (unsigned) bp_unpack_value (bp, 1);
