------- Comment #51 from rguenth at gcc dot gnu dot org 2010-07-09 11:47
-------
(In reply to comment #50)
> Created an attachment (id=21157)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21157&action=view) [edit]
> combined ptch for 44832/44874 - WIP
>
> For the unreduced testcase, I see differences regarding the labels do_subreg,
> done, and widen.
> Any idea why the LABEL_DECLs are kept only when emitting debug information?
because they are not used?
@@ -477,7 +490,16 @@ remove_unused_scope_block_p (tree scope)
type is used or not. */
else if (debug_info_level == DINFO_LEVEL_NORMAL
- || debug_info_level == DINFO_LEVEL_VERBOSE)
+ || debug_info_level == DINFO_LEVEL_VERBOSE
+ /* For labels that are still used in the IL, the decision
+ to preserve them must not depend DEBUG_INFO_LEVEL,
+ otherwise we risk having different ordering in debug vs.
+ non-debug builds during inlining or versioning.
+ A label appearing here (we have already checked
+ DECL_IGNORED_P) should not be used in the IL unless it has
+ been explicitly used before, so we use TREE_USED as an
+ approximation. */
+ || (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t)))
please instead add a similar case to that of
TREE_CODE (*t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*t) instead of
amending the debuginfo level checks.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44832
