diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build index 905ea86d751..14b1a5364e3 100644 --- a/src/compiler/nir/meson.build +++ b/src/compiler/nir/meson.build @@ -194,6 +194,7 @@ files_libnir = files( 'nir_lower_samplers.c', 'nir_lower_scratch.c', 'nir_lower_shader_calls.c', + 'nir_lower_single_sampled.c', 'nir_lower_ssbo.c', 'nir_lower_subgroups.c', 'nir_lower_system_values.c', diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 08ffa825b5b..a25dea1bf4d 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -4860,6 +4860,8 @@ bool nir_lower_uniforms_to_ubo(nir_shader *shader, bool dword_packed, bool load_ bool nir_lower_is_helper_invocation(nir_shader *shader); +bool nir_lower_single_sampled(nir_shader *shader); + typedef struct nir_lower_subgroups_options { uint8_t subgroup_size; uint8_t ballot_bit_size; diff --git a/src/compiler/nir/nir_lower_single_sampled.c b/src/compiler/nir/nir_lower_single_sampled.c new file mode 100644 index 00000000000..5d793d8f2d0 --- /dev/null +++ b/src/compiler/nir/nir_lower_single_sampled.c @@ -0,0 +1,128 @@ +/* + * Copyright © 2021 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. + */ + +#include "nir.h" +#include "nir_builder.h" + +static bool +lower_single_sampled_instr(nir_builder *b, + nir_instr *instr, + UNUSED void *cb_data) +{ + if (instr->type != nir_instr_type_intrinsic) + return false; + + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); + + nir_ssa_def *lowered; + switch (intrin->intrinsic) { + case nir_intrinsic_load_sample_id: + b->cursor = nir_before_instr(instr); + lowered = nir_imm_int(b, 0); + break; + + case nir_intrinsic_load_sample_pos: + b->cursor = nir_before_instr(instr); + lowered = nir_imm_vec2(b, 0.5, 0.5); + break; + + case nir_intrinsic_load_sample_mask_in: + /* Don't lower to helper invocations if helper invocations are going + * to be lowered right back to sample mask. + */ + if (b->shader->options->lower_helper_invocation) + return false; + + b->cursor = nir_before_instr(instr); + lowered = nir_b2i32(b, nir_inot(b, nir_load_helper_invocation(b, 1))); + break; + + case nir_intrinsic_interp_deref_at_centroid: + case nir_intrinsic_interp_deref_at_sample: + b->cursor = nir_before_instr(instr); + assert(intrin->src[0].is_ssa); + lowered = nir_load_deref(b, nir_src_as_deref(intrin->src[0])); + break; + + case nir_intrinsic_load_barycentric_centroid: + case nir_intrinsic_load_barycentric_sample: + case nir_intrinsic_load_barycentric_at_sample: + b->cursor = nir_before_instr(instr); + lowered = nir_load_barycentric(b, nir_intrinsic_load_barycentric_pixel, + nir_intrinsic_interp_mode(intrin)); + + if (nir_intrinsic_interp_mode(intrin) == INTERP_MODE_NOPERSPECTIVE) { + BITSET_SET(b->shader->info.system_values_read, + SYSTEM_VALUE_BARYCENTRIC_LINEAR_PIXEL); + } else { + BITSET_SET(b->shader->info.system_values_read, + SYSTEM_VALUE_BARYCENTRIC_PERSP_PIXEL); + } + break; + + default: + return false; + } + + nir_ssa_def_rewrite_uses(&intrin->dest.ssa, lowered); + nir_instr_remove(instr); + return true; +} + +/* Assume the fragment shader is single-sampled and lower accordingly + * + * This drops sample/centroid qualifiers from all input variables, forces + * barycentrics to pixel, and constant-folds various built-ins. + */ +bool +nir_lower_single_sampled(nir_shader *shader) +{ + assert(shader->info.stage == MESA_SHADER_FRAGMENT); + + bool progress = false; + nir_foreach_shader_in_variable(var, shader) { + if (var->data.sample) { + var->data.sample = false; + progress = true; + } + if (var->data.centroid) { + var->data.centroid = false; + progress = true; + } + } + + /* We're going to get rid of any uses of these */ + BITSET_CLEAR(shader->info.system_values_read, + SYSTEM_VALUE_BARYCENTRIC_PERSP_SAMPLE); + BITSET_CLEAR(shader->info.system_values_read, + SYSTEM_VALUE_BARYCENTRIC_PERSP_CENTROID); + BITSET_CLEAR(shader->info.system_values_read, + SYSTEM_VALUE_BARYCENTRIC_LINEAR_SAMPLE); + BITSET_CLEAR(shader->info.system_values_read, + SYSTEM_VALUE_BARYCENTRIC_LINEAR_CENTROID); + + return nir_shader_instructions_pass(shader, lower_single_sampled_instr, + nir_metadata_block_index | + nir_metadata_dominance, + NULL) || progress; +}