diff options
| -rw-r--r-- | src/glsl/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/glsl/nir/nir.h | 1 | ||||
| -rw-r--r-- | src/glsl/nir/nir_lower_load_const_to_scalar.c | 103 |
3 files changed, 105 insertions, 0 deletions
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources index 93f4e48..a0e85ed 100644 --- a/src/glsl/Makefile.sources +++ b/src/glsl/Makefile.sources @@ -33,6 +33,7 @@ NIR_FILES = \ nir/nir_lower_alu_to_scalar.c \ nir/nir_lower_atomics.c \ nir/nir_lower_global_vars_to_local.c \ + nir/nir_lower_load_const_to_scalar.c \ nir/nir_lower_locals_to_regs.c \ nir/nir_lower_idiv.c \ nir/nir_lower_io.c \ diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h index 0603b3e..9aae6d7 100644 --- a/src/glsl/nir/nir.h +++ b/src/glsl/nir/nir.h @@ -1654,6 +1654,7 @@ void nir_remove_dead_variables(nir_shader *shader); void nir_lower_vec_to_movs(nir_shader *shader); void nir_lower_alu_to_scalar(nir_shader *shader); +void nir_lower_load_const_to_scalar(nir_shader *shader); void nir_lower_phis_to_scalar(nir_shader *shader); diff --git a/src/glsl/nir/nir_lower_load_const_to_scalar.c b/src/glsl/nir/nir_lower_load_const_to_scalar.c new file mode 100644 index 0000000..a90e524 --- /dev/null +++ b/src/glsl/nir/nir_lower_load_const_to_scalar.c @@ -0,0 +1,103 @@ +/* + * 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 void +lower_load_const_instr_scalar(nir_load_const_instr *lower) +{ + if (lower->def.num_components == 1) + return; + + nir_builder b; + nir_builder_init(&b, nir_cf_node_get_function(&lower->instr.block->cf_node)); + nir_builder_insert_before_instr(&b, &lower->instr); + + /* Emit the individual loads. */ + nir_ssa_def *loads[4]; + for (unsigned i = 0; i < lower->def.num_components; i++) { + nir_load_const_instr *load_comp = nir_load_const_instr_create(b.shader, 1); + load_comp->value.u[0] = lower->value.u[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; + switch (lower->def.num_components) { + case 2: + vec = nir_vec2(&b, loads[0], loads[1]); + break; + case 3: + vec = nir_vec3(&b, loads[0], loads[1], loads[2]); + break; + case 4: + vec = nir_vec4(&b, loads[0], loads[1], loads[2], loads[3]); + break; + default: + unreachable("Unknown load_const component count."); + } + + /* Replace the old load with a reference to our reconstructed vector. */ + nir_ssa_def_rewrite_uses(&lower->def, nir_src_for_ssa(vec), + ralloc_parent(b.impl)); + nir_instr_remove(&lower->instr); +} + +static bool +lower_load_const_to_scalar_block(nir_block *block, void *data) +{ + nir_foreach_instr_safe(block, instr) { + if (instr->type == nir_instr_type_load_const) + lower_load_const_instr_scalar(nir_instr_as_load_const(instr)); + } + + return true; +} + +static void +nir_lower_load_const_to_scalar_impl(nir_function_impl *impl) +{ + nir_foreach_block(impl, lower_load_const_to_scalar_block, NULL); +} + +void +nir_lower_load_const_to_scalar(nir_shader *shader) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_lower_load_const_to_scalar_impl(overload->impl); + } +} |