http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56742
--- Comment #4 from Kai Tietz <ktietz at gcc dot gnu.org> 2013-03-27 09:40:16
UTC ---
(In reply to comment #3)
> (In reply to comment #2)
> > Hmm, yes indeed it is the -freorder-blocks option. One solution is to
> > disallow after reload for SEH-target to modify jumps.
>
> That's an awfully big hammer. Perhaps it's possible to first analyze
> what is actually happening in bbreorder that causes this bug?
Well, the issue is analyzed. The issue is that SEH is table-based EH, and so
after bb-reorder used labels for describing eh-regions are getting invalid.
If you take a look to the produces assembly for the example, you will notice
that easily.
I admit that the first patch is a bit too invasive, as it disables bb-reorder
in all cases. But in fact we need to disable it just if there is a
catch-region. A more improved variant is:
Index: i386.c
===================================================================
--- i386.c (Revision 197118)
+++ i386.c (Arbeitskopie)
@@ -3941,6 +3941,20 @@
register_pass (&insert_vzeroupper_info);
}
+/* Implement TARGET_CANNOT_MODIFY_JUMPS_P. */
+static bool
+ix86_cannot_modify_jumps_p (void)
+{
+ if (TARGET_SEH && reload_completed
+ && cfun && cfun->eh
+ && cfun->eh->region_tree)
+ return true;
+ return false;
+}
+
+#undef TARGET_CANNOT_MODIFY_JUMPS_P
+#define TARGET_CANNOT_MODIFY_JUMPS_P ix86_cannot_modify_jumps_p
+
/* Update register usage after having seen the compiler flags. */
static void
