| /* |
| * Copyright © 2015 Broadcom |
| * |
| * 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. |
| */ |
| |
| #include "util/macros.h" |
| #include "nir.h" |
| #include "nir_builder.h" |
| |
| /** @file nir_lower_load_const_to_scalar.c |
| * |
| * Replaces vector nir_load_const instructions with a series of loads and a |
| * vec[234] to reconstruct the original vector (on the assumption that |
| * nir_lower_alu_to_scalar() will then be used to split it up). |
| * |
| * This gives NIR a chance to CSE more operations on a scalar shader, when the |
| * same value was used in different vector contant loads. |
| */ |
| |
| static bool |
| lower_load_const_instr_scalar(nir_load_const_instr *lower) |
| { |
| if (lower->def.num_components == 1) |
| return false; |
| |
| nir_builder b; |
| nir_builder_init(&b, nir_cf_node_get_function(&lower->instr.block->cf_node)); |
| b.cursor = nir_before_instr(&lower->instr); |
| |
| /* Emit the individual loads. */ |
| nir_ssa_def *loads[NIR_MAX_VEC_COMPONENTS]; |
| for (unsigned i = 0; i < lower->def.num_components; i++) { |
| nir_load_const_instr *load_comp = |
| nir_load_const_instr_create(b.shader, 1, lower->def.bit_size); |
| load_comp->value[0] = lower->value[i]; |
| nir_builder_instr_insert(&b, &load_comp->instr); |
| loads[i] = &load_comp->def; |
| } |
| |
| /* Batch things back together into a vector. */ |
| nir_ssa_def *vec = nir_vec(&b, loads, lower->def.num_components); |
| |
| /* Replace the old load with a reference to our reconstructed vector. */ |
| nir_ssa_def_rewrite_uses(&lower->def, vec); |
| nir_instr_remove(&lower->instr); |
| return true; |
| } |
| |
| static bool |
| nir_lower_load_const_to_scalar_impl(nir_function_impl *impl) |
| { |
| bool progress = false; |
| |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type == nir_instr_type_load_const) |
| progress |= |
| lower_load_const_instr_scalar(nir_instr_as_load_const(instr)); |
| } |
| } |
| |
| if (progress) { |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| } else { |
| nir_metadata_preserve(impl, nir_metadata_all); |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_lower_load_const_to_scalar(nir_shader *shader) |
| { |
| bool progress = false; |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl) |
| progress |= nir_lower_load_const_to_scalar_impl(function->impl); |
| } |
| |
| return progress; |
| } |