freedreno/ir3: sched should mark outputs used

Account for shader outputs and values live in any direct/indirect
successor block.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/freedreno/ir3/ir3_sched.c b/src/freedreno/ir3/ir3_sched.c
index dd9567764f76cce5508573daa3d9bb45af1f5e20..16199ca3fb97dde4a44d7b8fbefe9def7485c079 100644 (file)
--- a/src/freedreno/ir3/ir3_sched.c
+++ b/src/freedreno/ir3/ir3_sched.c
@@ -87,6 +87,8 @@ unuse_each_src(struct ir3_sched_ctx *ctx, struct ir3_instruction *instr)
        }
 }
 
+static void use_instr(struct ir3_instruction *instr);
+
 static void
 use_each_src(struct ir3_instruction *instr)
 {
@@ -95,13 +97,17 @@ use_each_src(struct ir3_instruction *instr)
        foreach_ssa_src_n(src, n, instr) {
                if (__is_false_dep(instr, n))
                        continue;
-               if (instr->block != src->block)
-                       continue;
-               if ((src->opc == OPC_META_FI) || (src->opc == OPC_META_FO)) {
-                       use_each_src(src);
-               } else {
-                       src->use_count++;
-               }
+               use_instr(src);
+       }
+}
+
+static void
+use_instr(struct ir3_instruction *instr)
+{
+       if ((instr->opc == OPC_META_FI) || (instr->opc == OPC_META_FO)) {
+               use_each_src(instr);
+       } else {
+               instr->use_count++;
        }
 }
 
@@ -115,23 +121,33 @@ update_live_values(struct ir3_sched_ctx *ctx, struct ir3_instruction *instr)
        unuse_each_src(ctx, instr);
 }
 
-/* This is *slightly* different than how ir3_cp uses use_count, in that
- * we just track it per block (because we schedule a block at a time) and
- * because we don't track meta instructions and false dependencies (since
- * they don't contribute real register pressure).
- */
 static void
-update_use_count(struct ir3_block *block)
+update_use_count(struct ir3 *ir)
 {
-       list_for_each_entry (struct ir3_instruction, instr, &block->instr_list, node) {
-               instr->use_count = 0;
+       list_for_each_entry (struct ir3_block, block, &ir->block_list, node) {
+               list_for_each_entry (struct ir3_instruction, instr, &block->instr_list, node) {
+                       instr->use_count = 0;
+               }
        }
 
-       list_for_each_entry (struct ir3_instruction, instr, &block->instr_list, node) {
-               if ((instr->opc == OPC_META_FI) || (instr->opc == OPC_META_FO))
+       list_for_each_entry (struct ir3_block, block, &ir->block_list, node) {
+               list_for_each_entry (struct ir3_instruction, instr, &block->instr_list, node) {
+                       if ((instr->opc == OPC_META_FI) || (instr->opc == OPC_META_FO))
+                               continue;
+
+                       use_each_src(instr);
+               }
+       }
+
+       /* Shader outputs are also used:
+        */
+       for (unsigned i = 0; i <  ir->noutputs; i++) {
+               struct ir3_instruction  *out = ir->outputs[i];
+
+               if (!out)
                        continue;
 
-               use_each_src(instr);
+               use_instr(out);
        }
 }
 
@@ -790,10 +806,10 @@ int ir3_sched(struct ir3 *ir)
        struct ir3_sched_ctx ctx = {0};
 
        ir3_clear_mark(ir);
+       update_use_count(ir);
 
        list_for_each_entry (struct ir3_block, block, &ir->block_list, node) {
                ctx.live_values = 0;
-               update_use_count(block);
                sched_block(&ctx, block);
        }