diff options
| -rw-r--r-- | src/compiler/nir/nir_remove_dead_variables.c | 69 |
1 files changed, 60 insertions, 9 deletions
diff --git a/src/compiler/nir/nir_remove_dead_variables.c b/src/compiler/nir/nir_remove_dead_variables.c index e0eaa3dc23b..a1fe0de9c61 100644 --- a/src/compiler/nir/nir_remove_dead_variables.c +++ b/src/compiler/nir/nir_remove_dead_variables.c @@ -31,9 +31,27 @@ static void add_var_use_intrinsic(nir_intrinsic_instr *instr, struct set *live) { unsigned num_vars = nir_intrinsic_infos[instr->intrinsic].num_variables; - for (unsigned i = 0; i < num_vars; i++) { - nir_variable *var = instr->variables[i]->var; - _mesa_set_add(live, var); + + switch (instr->intrinsic) { + case nir_intrinsic_copy_var: + _mesa_set_add(live, instr->variables[1]->var); + /* Fall through */ + case nir_intrinsic_store_var: { + /* The first source in both copy_var and store_var is the destination. + * If the variable is a local that never escapes the shader, then we + * don't mark it as live for just a store. + */ + nir_variable_mode mode = instr->variables[0]->var->data.mode; + if (!(mode & (nir_var_local | nir_var_global | nir_var_shared))) + _mesa_set_add(live, instr->variables[0]->var); + break; + } + + default: + for (unsigned i = 0; i < num_vars; i++) { + _mesa_set_add(live, instr->variables[i]->var); + } + break; } } @@ -94,6 +112,31 @@ add_var_use_shader(nir_shader *shader, struct set *live) } } +static void +remove_dead_var_writes(nir_shader *shader, struct set *live) +{ + nir_foreach_function(function, shader) { + if (!function->impl) + continue; + + nir_foreach_block(block, function->impl) { + nir_foreach_instr_safe(instr, block) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); + if (intrin->intrinsic != nir_intrinsic_copy_var && + intrin->intrinsic != nir_intrinsic_store_var) + continue; + + /* Stores to dead variables need to be removed */ + if (intrin->variables[0]->var->data.mode == 0) + nir_instr_remove(instr); + } + } + } +} + static bool remove_dead_vars(struct exec_list *var_list, struct set *live) { @@ -102,8 +145,9 @@ remove_dead_vars(struct exec_list *var_list, struct set *live) foreach_list_typed_safe(nir_variable, var, node, var_list) { struct set_entry *entry = _mesa_set_search(live, var); if (entry == NULL) { + /* Mark this variable as used by setting the mode to 0 */ + var->data.mode = 0; exec_node_remove(&var->node); - ralloc_free(var); progress = true; } } @@ -141,12 +185,19 @@ nir_remove_dead_variables(nir_shader *shader, nir_variable_mode modes) if (modes & nir_var_local) { nir_foreach_function(function, shader) { if (function->impl) { - if (remove_dead_vars(&function->impl->locals, live)) { - nir_metadata_preserve(function->impl, nir_metadata_block_index | - nir_metadata_dominance | - nir_metadata_live_ssa_defs); + if (remove_dead_vars(&function->impl->locals, live)) progress = true; - } + } + } + } + + if (progress) { + remove_dead_var_writes(shader, live); + + nir_foreach_function(function, shader) { + if (function->impl) { + nir_metadata_preserve(function->impl, nir_metadata_block_index | + nir_metadata_dominance); } } } |