On Tue, Oct 30, 2012 at 6:48 PM, Steven Bosscher <stevenb....@gmail.com> wrote:
> On Tue, Oct 30, 2012 at 6:20 AM, Teresa Johnson wrote:
>> Index: bb-reorder.c
>> ===================================================================
>> --- bb-reorder.c (revision 192692)
>> +++ bb-reorder.c (working copy)
>> @@ -2188,6 +2188,8 @@ insert_section_boundary_note (void)
>> first_partition = BB_PARTITION (bb);
>> if (BB_PARTITION (bb) != first_partition)
>> {
>> + /* There should be a barrier between text sections. */
>> + emit_barrier_after (BB_END (bb->prev_bb));
>
> So why isn't there one? There can't be a fall-through edge from one
> section to the other, so cfgrtl.c:fixup_reorder_chain should have
> added a barrier here already in the code under the comment:
>
> /* Now add jumps and labels as needed to match the blocks new
> outgoing edges. */
>
> Why isn't it doing that for you?
Maybe it's because fix_up_fall_thru_edges calls force_nonfallthru,
which is incorrectly inserting JUMP_INSNs and BARRIERs in cfglayout
mode. I'm going to test this patch:
Index: cfgrtl.c
===================================================================
--- cfgrtl.c (revision 192889)
+++ cfgrtl.c (working copy)
@@ -1511,16 +1511,17 @@ force_nonfallthru_and_redirect (edge e,
#endif
}
set_return_jump_label (BB_END (jump_block));
+ emit_barrier_after (BB_END (jump_block));
}
- else
+ else if (current_ir_type () == IR_RTL_CFGRTL)
{
rtx label = block_label (target);
emit_jump_insn_after_setloc (gen_jump (label), BB_END (jump_block), loc);
JUMP_LABEL (BB_END (jump_block)) = label;
LABEL_NUSES (label)++;
+ emit_barrier_after (BB_END (jump_block));
}
- emit_barrier_after (BB_END (jump_block));
redirect_edge_succ_nodup (e, target);
if (abnormal_edge_flags)
