On Tue, 1 Dec 2015, Jan Hubicka wrote:
> Hi,
> this patch disables the streaming of alias 0 flag and adds a comment why.
>
> Bootstrapped/regtested x86_64-linux, OK?
Ok.
Thanks,
Richard.
> 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);
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
