This makes the schedule more aggressive about hiding latency, but being
able to dynamically switch to another strategy once our register
pressure increases beyond a certain point should help here.
total instructions in shared programs: 7460652 -> 7461304 (0.01%)
instructions in affected programs: 6055 -> 6707 (10.77%)
helped: 1
HURT: 8
total cycles in shared programs: 52874386 -> 50180046 (-5.10%)
cycles in affected programs: 50336130 -> 47641790 (-5.35%)
helped: 58987
HURT: 1004
LOST: 3
GAINED: 0
Signed-off-by: Connor Abbott <cwabbo...@gmail.com>
---
.../drivers/dri/i965/brw_schedule_instructions.cpp | 24 ++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
b/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
index a611dd1..3ae8c3f 100644
--- a/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
+++ b/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
@@ -1396,15 +1396,27 @@
fs_instruction_scheduler::choose_instruction_to_schedule()
schedule_node *chosen = NULL;
if (mode == SCHEDULE_PRE || mode == SCHEDULE_POST) {
- int chosen_time = 0;
-
- /* Of the instructions ready to execute or the closest to
- * being ready, choose the oldest one.
+ int chosen_unblocked_time = 0, chosen_delay = 0;
+
+ /* First, find the earliest instruction we can possibly schedule. Then,
+ * if there are multiple instructions that we can schedule at the same
+ * time, choose the thing with the longest critical path. The idea here
+ * is to try not to lengthen already larger critical path lengths, but
+ * if we can, we should first schedule instructions that we can fit in
+ * before the instruction with the longest critical path. There might be
+ * some cases where we still bump the critical path instruction, but
+ * this seems unlikely, given that most instructions have the same issue
+ * time and most latencies are a multiple of the issue time.
*/
foreach_in_list(schedule_node, n, &instructions) {
- if (!chosen || n->unblocked_time < chosen_time) {
+ int unblocked_time = MAX2(n->unblocked_time, time);
+ if (!chosen ||
+ unblocked_time < chosen_unblocked_time ||
+ (unblocked_time == chosen_unblocked_time &&
+ n->delay > chosen_delay)) {
chosen = n;
- chosen_time = n->unblocked_time;
+ chosen_unblocked_time = unblocked_time;
+ chosen_delay = n->delay;
}
}
} else {
--
2.4.3
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
