On Tue, Nov 27, 2012 at 1:28 PM, Steven Bosscher wrote:
> Dominique, could you give this a try and see if it helps?
> (But as I said up-thread: I'm not sure this is a proper fix, or just
> another band-aid...)
And more band-aid, but this time I'm not even sure where things go
wrong. In any case, we end up with a REG_EQUAL note referencing a
SUBREG of a dead register. This leaked because df_remove_dead_eq_notes
uses loc_mentioned_in_p not on the note but on the first operand of
the note.
Index: df-problems.c
===================================================================
--- df-problems.c (revision 193394)
+++ df-problems.c (working copy)
@@ -2907,9 +2907,10 @@ df_remove_dead_eq_notes (rtx insn, bitma
if (DF_REF_REGNO (use) > FIRST_PSEUDO_REGISTER
&& DF_REF_LOC (use)
&& (DF_REF_FLAGS (use) & DF_REF_IN_NOTE)
- && ! bitmap_bit_p (live, DF_REF_REGNO (use))
- && loc_mentioned_in_p (DF_REF_LOC (use), XEXP (link, 0)))
+ && ! bitmap_bit_p (live, DF_REF_REGNO (use)))
{
+ /* Make sure that DF_SCAN is up-to-date. */
+ gcc_assert (loc_mentioned_in_p (DF_REF_LOC (use), link));
deleted = true;
break;
}
