We can bundle two load/store together. This eliminates the need for
explicit load/store pairing in a prepass, as well.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzw...@collabora.com>
---
src/panfrost/midgard/midgard_schedule.c | 67 +++++--------------------
1 file changed, 12 insertions(+), 55 deletions(-)
diff --git a/src/panfrost/midgard/midgard_schedule.c
b/src/panfrost/midgard/midgard_schedule.c
index 92756e15189..e2641ea0180 100644
--- a/src/panfrost/midgard/midgard_schedule.c
+++ b/src/panfrost/midgard/midgard_schedule.c
@@ -1141,17 +1141,26 @@ mir_schedule_ldst(
.exclude = ~0
};
+ /* Try to pick two load/store ops. Second not gauranteed to exist */
+
midgard_instruction *ins =
mir_choose_instruction(instructions, worklist, len,
&predicate);
- mir_update_worklist(worklist, len, instructions, ins);
+ midgard_instruction *pair =
+ mir_choose_instruction(instructions, worklist, len,
&predicate);
struct midgard_bundle out = {
.tag = TAG_LOAD_STORE_4,
- .instruction_count = 1,
- .instructions = { ins }
+ .instruction_count = pair ? 2 : 1,
+ .instructions = { ins, pair }
};
+ /* We have to update the worklist atomically, since the two
+ * instructions run concurrently (TODO: verify it's not pipelined) */
+
+ mir_update_worklist(worklist, len, instructions, ins);
+ mir_update_worklist(worklist, len, instructions, pair);
+
return out;
}
@@ -1341,54 +1350,6 @@ schedule_block(compiler_context *ctx, midgard_block
*block)
ctx->quadword_count += block->quadword_count;
}
-/* The following passes reorder MIR instructions to enable better scheduling */
-
-static void
-midgard_pair_load_store(compiler_context *ctx, midgard_block *block)
-{
- mir_foreach_instr_in_block_safe(block, ins) {
- if (ins->type != TAG_LOAD_STORE_4) continue;
-
- /* We've found a load/store op. Check if next is also
load/store. */
- midgard_instruction *next_op = mir_next_op(ins);
- if (&next_op->link != &block->instructions) {
- if (next_op->type == TAG_LOAD_STORE_4) {
- /* If so, we're done since we're a pair */
- ins = mir_next_op(ins);
- continue;
- }
-
- /* Maximum search distance to pair, to avoid register
pressure disasters */
- int search_distance = 8;
-
- /* Otherwise, we have an orphaned load/store -- search
for another load */
- mir_foreach_instr_in_block_from(block, c,
mir_next_op(ins)) {
- /* Terminate search if necessary */
- if (!(search_distance--)) break;
-
- if (c->type != TAG_LOAD_STORE_4) continue;
-
- /* We can only reorder if there are no sources
*/
-
- bool deps = false;
-
- for (unsigned s = 0; s < ARRAY_SIZE(ins->src);
++s)
- deps |= (c->src[s] != ~0);
-
- if (deps)
- continue;
-
- /* We found one! Move it up to pair and remove
it from the old location */
-
- mir_insert_instruction_before(ctx, ins, *c);
- mir_remove_instruction(c);
-
- break;
- }
- }
- }
-}
-
/* When we're 'squeezing down' the values in the IR, we maintain a hash
* as such */
@@ -1665,10 +1626,6 @@ schedule_program(compiler_context *ctx)
midgard_promote_uniforms(ctx, 16);
- mir_foreach_block(ctx, block) {
- midgard_pair_load_store(ctx, block);
- }
-
/* Must be lowered right before RA */
mir_squeeze_index(ctx);
mir_lower_special_reads(ctx);
--
2.23.0
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
