/* * 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); switch (lower->def.bit_size) { case 64: load_comp->value.u64[0] = lower->value.u64[i]; break; case 32: load_comp->value.u32[0] = lower->value.u32[i]; break; case 16: load_comp->value.u16[0] = lower->value.u16[i]; break; case 8: load_comp->value.u8[0] = lower->value.u8[i]; break; case 1: load_comp->value.b[0] = lower->value.b[i]; break; default: assert(!"invalid bit size"); } 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, nir_src_for_ssa(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 { #ifndef NDEBUG impl->valid_metadata &= ~nir_metadata_not_properly_reset; #endif } 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; }