Hi,
enabling bb reorering has quite visible code size effect due to disabling two
optimization - the small block duplication in connect_traces and post-reload
crossjumping. Small block duplication seems easy enough to allow within one
partition. While doing so i also noticed that my changes to counts disabled
most of duplication which makes code grow. This is because uninitialized count
is not greater than any threshold.
bootstrapped/regtested x86_64-linux, comitted.
Honza
* bb-reorder.c (connect_traces): Allow copying of blocks within
single partition.
Index: bb-reorder.c
===================================================================
--- bb-reorder.c (revision 250378)
+++ bb-reorder.c (working copy)
@@ -1302,16 +1302,15 @@ connect_traces (int n_traces, struct tra
}
}
- if (crtl->has_bb_partition)
- try_copy = false;
-
/* Copy tiny blocks always; copy larger blocks only when the
edge is traversed frequently enough. */
if (try_copy
+ && BB_PARTITION (best->src) == BB_PARTITION (best->dest)
&& copy_bb_p (best->dest,
optimize_edge_for_speed_p (best)
&& EDGE_FREQUENCY (best) >= freq_threshold
- && best->count >= count_threshold))
+ && (!best->count.initialized_p ()
+ || best->count >= count_threshold)))
{
basic_block new_bb;
