Commit 7b208a73 authored by Matt Turner's avatar Matt Turner
Browse files

i965: Relax restriction on scheduling last instruction.



I think when this code was written, basic blocks were always ended by a
control flow instruction or an end-of-thread message. That's no longer
the case, and removing this restriction actually helps things:

   instructions in affected programs: 7267 -> 7244 (-0.32%)
   helped: 4

   total cycles in shared programs: 66559580 -> 66431900 (-0.19%)
   cycles in affected programs: 28310152 -> 28182472 (-0.45%)
   helped: 9577
   HURT: 879

   GAINED: 2

The addition of the is_control_flow() checks is not a functional change,
since the add_insts_from_block() does not put them in the list of
instructions to schedule. I plan to change this in a later patch.
Reviewed-by: Francisco Jerez's avatarFrancisco Jerez <currojerez@riseup.net>
parent f6075096
......@@ -923,15 +923,6 @@ fs_instruction_scheduler::calculate_deps()
*/
schedule_node *last_fixed_grf_write = NULL;
/* The last instruction always needs to still be the last
* instruction. Either it's flow control (IF, ELSE, ENDIF, DO,
* WHILE) and scheduling other things after it would disturb the
* basic block, or it's FB_WRITE and we should do a better job at
* dead code elimination anyway.
*/
schedule_node *last = (schedule_node *)instructions.get_tail();
add_barrier_deps(last);
memset(last_grf_write, 0, sizeof(last_grf_write));
memset(last_mrf_write, 0, sizeof(last_mrf_write));
......@@ -940,6 +931,7 @@ fs_instruction_scheduler::calculate_deps()
fs_inst *inst = (fs_inst *)n->inst;
if (inst->opcode == FS_OPCODE_PLACEHOLDER_HALT ||
inst->is_control_flow() ||
inst->has_side_effects())
add_barrier_deps(n);
......@@ -1166,15 +1158,6 @@ vec4_instruction_scheduler::calculate_deps()
*/
schedule_node *last_fixed_grf_write = NULL;
/* The last instruction always needs to still be the last instruction.
* Either it's flow control (IF, ELSE, ENDIF, DO, WHILE) and scheduling
* other things after it would disturb the basic block, or it's the EOT
* URB_WRITE and we should do a better job at dead code eliminating
* anything that could have been scheduled after it.
*/
schedule_node *last = (schedule_node *)instructions.get_tail();
add_barrier_deps(last);
memset(last_grf_write, 0, sizeof(last_grf_write));
memset(last_mrf_write, 0, sizeof(last_mrf_write));
......@@ -1182,7 +1165,7 @@ vec4_instruction_scheduler::calculate_deps()
foreach_in_list(schedule_node, n, &instructions) {
vec4_instruction *inst = (vec4_instruction *)n->inst;
if (inst->has_side_effects())
if (inst->is_control_flow() || inst->has_side_effects())
add_barrier_deps(n);
/* read-after-write deps. */
......
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