/* * Copyright © 2014 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. * * Authors: * Connor Abbott (cwabbott0@gmail.com) * */ #include "nir.h" 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); } } static void add_var_use_call(nir_call_instr *instr, struct set *live) { if (instr->return_deref != NULL) { nir_variable *var = instr->return_deref->var; _mesa_set_add(live, var); } for (unsigned i = 0; i < instr->num_params; i++) { nir_variable *var = instr->params[i]->var; _mesa_set_add(live, var); } } static void add_var_use_tex(nir_tex_instr *instr, struct set *live) { if (instr->texture != NULL) { nir_variable *var = instr->texture->var; _mesa_set_add(live, var); } if (instr->sampler != NULL) { nir_variable *var = instr->sampler->var; _mesa_set_add(live, var); } } static bool add_var_use_block(nir_block *block, void *state) { struct set *live = state; nir_foreach_instr(block, instr) { switch(instr->type) { case nir_instr_type_intrinsic: add_var_use_intrinsic(nir_instr_as_intrinsic(instr), live); break; case nir_instr_type_call: add_var_use_call(nir_instr_as_call(instr), live); break; case nir_instr_type_tex: add_var_use_tex(nir_instr_as_tex(instr), live); break; default: break; } } return true; } static void add_var_use_shader(nir_shader *shader, struct set *live) { nir_foreach_function(shader, function) { if (function->impl) { nir_foreach_block(function->impl, add_var_use_block, live); } } } static bool remove_dead_vars(struct exec_list *var_list, struct set *live) { bool progress = false; foreach_list_typed_safe(nir_variable, var, node, var_list) { struct set_entry *entry = _mesa_set_search(live, var); if (entry == NULL) { exec_node_remove(&var->node); ralloc_free(var); progress = true; } } return progress; } bool nir_remove_dead_variables(nir_shader *shader) { bool progress = false; struct set *live = _mesa_set_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal); add_var_use_shader(shader, live); progress = remove_dead_vars(&shader->globals, live) || progress; nir_foreach_function(shader, function) { 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); progress = true; } } } _mesa_set_destroy(live, NULL); return progress; }