| /* |
| * 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; |
| |
| 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; |
| } |
| } |
| |
| 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 void |
| add_var_use_shader(nir_shader *shader, struct set *live) |
| { |
| nir_foreach_function(function, shader) { |
| if (function->impl) { |
| nir_foreach_block(block, function->impl) { |
| nir_foreach_instr(instr, block) { |
| 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; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| 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) |
| { |
| 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) { |
| /* Mark this variable as used by setting the mode to 0 */ |
| var->data.mode = 0; |
| exec_node_remove(&var->node); |
| progress = true; |
| } |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_remove_dead_variables(nir_shader *shader, nir_variable_mode modes) |
| { |
| bool progress = false; |
| struct set *live = |
| _mesa_set_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal); |
| |
| add_var_use_shader(shader, live); |
| |
| if (modes & nir_var_uniform) |
| progress = remove_dead_vars(&shader->uniforms, live) || progress; |
| |
| if (modes & nir_var_shader_in) |
| progress = remove_dead_vars(&shader->inputs, live) || progress; |
| |
| if (modes & nir_var_shader_out) |
| progress = remove_dead_vars(&shader->outputs, live) || progress; |
| |
| if (modes & nir_var_global) |
| progress = remove_dead_vars(&shader->globals, live) || progress; |
| |
| if (modes & nir_var_system_value) |
| progress = remove_dead_vars(&shader->system_values, live) || progress; |
| |
| if (modes & nir_var_shared) |
| progress = remove_dead_vars(&shader->shared, live) || progress; |
| |
| if (modes & nir_var_local) { |
| nir_foreach_function(function, shader) { |
| if (function->impl) { |
| 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); |
| } |
| } |
| } |
| |
| _mesa_set_destroy(live, NULL); |
| return progress; |
| } |
