diff options
Diffstat (limited to 'src/compiler/nir/nir_opt_gcm.c')
| -rw-r--r-- | src/compiler/nir/nir_opt_gcm.c | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/src/compiler/nir/nir_opt_gcm.c b/src/compiler/nir/nir_opt_gcm.c index aa20ab1667f..86432ab1ab5 100644 --- a/src/compiler/nir/nir_opt_gcm.c +++ b/src/compiler/nir/nir_opt_gcm.c @@ -343,11 +343,11 @@ gcm_schedule_late_def(nir_ssa_def *def, void *void_state) nir_block *early_block = state->instr_infos[def->parent_instr->index].early_block; - /* Some instructions may never be used. We'll just schedule them early and - * let dead code clean them up. + /* Some instructions may never be used. Flag them and the instruction + * placement code will get rid of them for us. */ if (lca == NULL) { - def->parent_instr->block = early_block; + def->parent_instr->block = NULL; return true; } @@ -410,6 +410,23 @@ gcm_place_instr_def(nir_ssa_def *def, void *state) return false; } +static bool +gcm_replace_def_with_undef(nir_ssa_def *def, void *void_state) +{ + struct gcm_state *state = void_state; + + if (list_is_empty(&def->uses) && list_is_empty(&def->if_uses)) + return true; + + nir_ssa_undef_instr *undef = + nir_ssa_undef_instr_create(state->impl->function->shader, + def->num_components, def->bit_size); + nir_instr_insert(nir_before_cf_list(&state->impl->body), &undef->instr); + nir_ssa_def_rewrite_uses(def, nir_src_for_ssa(&undef->def)); + + return true; +} + /** Places an instrution back into the program * * The earlier passes of GCM simply choose blocks for each instruction and @@ -433,6 +450,12 @@ gcm_place_instr(nir_instr *instr, struct gcm_state *state) instr->pass_flags |= GCM_INSTR_PLACED; + if (instr->block == NULL) { + nir_foreach_ssa_def(instr, gcm_replace_def_with_undef, state); + nir_instr_remove(instr); + return; + } + /* Phi nodes are our once source of back-edges. Since right now we are * only doing scheduling within blocks, we don't need to worry about * them since they are always at the top. Just skip them completely. |