| /* |
| * 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: |
| * Jason Ekstrand (jason@jlekstrand.net) |
| * |
| */ |
| |
| /* |
| * This lowering pass detects when a global variable is only being used by |
| * one function and makes it local to that function |
| */ |
| |
| #include "nir.h" |
| |
| static void |
| register_var_use(nir_variable *var, nir_function_impl *impl, |
| struct hash_table *var_func_table) |
| { |
| if (var->data.mode != nir_var_shader_temp) |
| return; |
| |
| struct hash_entry *entry = |
| _mesa_hash_table_search(var_func_table, var); |
| |
| if (entry) { |
| if (entry->data != impl) |
| entry->data = NULL; |
| } else { |
| _mesa_hash_table_insert(var_func_table, var, impl); |
| } |
| } |
| |
| static bool |
| mark_global_var_uses_block(nir_block *block, nir_function_impl *impl, |
| struct hash_table *var_func_table) |
| { |
| nir_foreach_instr(instr, block) { |
| if (instr->type == nir_instr_type_deref) { |
| nir_deref_instr *deref = nir_instr_as_deref(instr); |
| if (deref->deref_type == nir_deref_type_var) |
| register_var_use(deref->var, impl, var_func_table); |
| } |
| } |
| |
| return true; |
| } |
| |
| bool |
| nir_lower_global_vars_to_local(nir_shader *shader) |
| { |
| bool progress = false; |
| |
| /* A hash table keyed on variable pointers that stores the unique |
| * nir_function_impl that uses the given variable. If a variable is |
| * used in multiple functions, the data for the given key will be NULL. |
| */ |
| struct hash_table *var_func_table = _mesa_pointer_hash_table_create(NULL); |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl) { |
| nir_foreach_block(block, function->impl) |
| mark_global_var_uses_block(block, function->impl, var_func_table); |
| } |
| } |
| |
| nir_foreach_variable_with_modes_safe(var, shader, nir_var_shader_temp) { |
| struct hash_entry *entry = _mesa_hash_table_search(var_func_table, var); |
| if (!entry) |
| continue; |
| |
| nir_function_impl *impl = entry->data; |
| |
| if (impl != NULL) { |
| exec_node_remove(&var->node); |
| var->data.mode = nir_var_function_temp; |
| exec_list_push_tail(&impl->locals, &var->node); |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance | |
| nir_metadata_live_ssa_defs); |
| progress = true; |
| } |
| } |
| |
| _mesa_hash_table_destroy(var_func_table, NULL); |
| |
| if (progress) |
| nir_fixup_deref_modes(shader); |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl) |
| nir_metadata_preserve(function->impl, nir_metadata_all); |
| } |
| |
| return progress; |
| } |