http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56729
--- Comment #5 from Steven Bosscher <steven at gcc dot gnu.org> 2013-03-27
23:45:30 UTC ---
Bah.
Index: df-scan.c
===================================================================
--- df-scan.c (revision 197180)
+++ df-scan.c (working copy)
@@ -1158,8 +1158,17 @@ df_insn_delete (rtx insn)
In any case, we expect BB to be non-NULL at least up to register
allocation, so disallow a non-NULL BB up to there. Not perfect
but better than nothing... */
-
+ /* ??? bb can also be NULL if lower-subreg.c:resolve_simple_mov emits
+ an insn into a sequence and then does delete_insn on it. Not sure
+ if that makes sense, but for now it means this assert cannot work.
+ See PR56738.
+ Disable for now but revisit before the end of GCC 4.9 stage1. */
+#if 0
gcc_checking_assert (bb != NULL || reload_completed);
+#else
+ if (bb == NULL)
+ return;
+#endif
df_grow_bb_info (df_scan);
df_grow_reg_info ();
