/* * 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. */ /** * This lowering pass supports (as configured via nir_lower_image_options) * image related conversions: * + cube array size lowering. The size operation is converted from cube * size to a 2d-array with the z component divided by 6. */ #include "nir.h" #include "nir_builder.h" static void lower_cube_size(nir_builder *b, nir_intrinsic_instr *intrin) { assert(nir_intrinsic_image_dim(intrin) == GLSL_SAMPLER_DIM_CUBE); b->cursor = nir_before_instr(&intrin->instr); nir_intrinsic_instr *_2darray_size = nir_instr_as_intrinsic(nir_instr_clone(b->shader, &intrin->instr)); nir_intrinsic_set_image_dim(_2darray_size, GLSL_SAMPLER_DIM_2D); nir_intrinsic_set_image_array(_2darray_size, true); nir_builder_instr_insert(b, &_2darray_size->instr); nir_def *size = nir_instr_def(&_2darray_size->instr); nir_scalar comps[NIR_MAX_VEC_COMPONENTS] = { 0 }; unsigned coord_comps = intrin->def.num_components; for (unsigned c = 0; c < coord_comps; c++) { if (c == 2) { comps[2] = nir_get_scalar(nir_idiv(b, nir_channel(b, size, 2), nir_imm_int(b, 6)), 0); } else { comps[c] = nir_get_scalar(size, c); } } nir_def *vec = nir_vec_scalars(b, comps, intrin->def.num_components); nir_def_replace(&intrin->def, vec); nir_instr_free(&intrin->instr); } /* Adjust the sample index according to AMD FMASK (fragment mask). * * For uncompressed MSAA surfaces, FMASK should return 0x76543210, * which is the identity mapping. Each nibble says which physical sample * should be fetched to get that sample. * * For example, 0x11111100 means there are only 2 samples stored and * the second sample covers 3/4 of the pixel. When reading samples 0 * and 1, return physical sample 0 (determined by the first two 0s * in FMASK), otherwise return physical sample 1. * * The sample index should be adjusted as follows: * sample_index = ubfe(fmask, sample_index * 4, 3); * * Only extract 3 bits because EQAA can generate number 8 in FMASK, which * means the physical sample index is unknown. We can map 8 to any valid * sample index, and extracting only 3 bits will map it to 0, which works * with all MSAA modes. */ static void lower_image_to_fragment_mask_load(nir_builder *b, nir_intrinsic_instr *intrin) { b->cursor = nir_before_instr(&intrin->instr); nir_intrinsic_op fmask_op; switch (intrin->intrinsic) { case nir_intrinsic_image_load: fmask_op = nir_intrinsic_image_fragment_mask_load_amd; break; case nir_intrinsic_image_deref_load: fmask_op = nir_intrinsic_image_deref_fragment_mask_load_amd; break; case nir_intrinsic_bindless_image_load: fmask_op = nir_intrinsic_bindless_image_fragment_mask_load_amd; break; default: unreachable("bad intrinsic"); break; } nir_def *fmask = nir_image_fragment_mask_load_amd(b, intrin->src[0].ssa, intrin->src[1].ssa, .image_dim = nir_intrinsic_image_dim(intrin), .image_array = nir_intrinsic_image_array(intrin), .format = nir_intrinsic_format(intrin), .access = nir_intrinsic_access(intrin)); /* fix intrinsic op */ nir_intrinsic_instr *fmask_load = nir_instr_as_intrinsic(fmask->parent_instr); fmask_load->intrinsic = fmask_op; /* extract real color buffer index from fmask buffer */ nir_def *sample_index_old = intrin->src[2].ssa; nir_def *fmask_offset = nir_u2u32(b, nir_ishl_imm(b, sample_index_old, 2)); nir_def *fmask_width = nir_imm_int(b, 3); nir_def *sample_index_new = nir_ubfe(b, fmask, fmask_offset, fmask_width); /* fix color buffer load */ nir_src_rewrite(&intrin->src[2], nir_u2uN(b, sample_index_new, sample_index_old->bit_size)); /* Mark uses fmask to prevent lower this intrinsic again. */ enum gl_access_qualifier access = nir_intrinsic_access(intrin); nir_intrinsic_set_access(intrin, access | ACCESS_FMASK_LOWERED_AMD); } static void lower_image_samples_identical_to_fragment_mask_load(nir_builder *b, nir_intrinsic_instr *intrin) { b->cursor = nir_before_instr(&intrin->instr); nir_intrinsic_instr *fmask_load = nir_instr_as_intrinsic(nir_instr_clone(b->shader, &intrin->instr)); switch (intrin->intrinsic) { case nir_intrinsic_image_samples_identical: fmask_load->intrinsic = nir_intrinsic_image_fragment_mask_load_amd; break; case nir_intrinsic_image_deref_samples_identical: fmask_load->intrinsic = nir_intrinsic_image_deref_fragment_mask_load_amd; break; case nir_intrinsic_bindless_image_samples_identical: fmask_load->intrinsic = nir_intrinsic_bindless_image_fragment_mask_load_amd; break; default: unreachable("bad intrinsic"); break; } nir_def_init(&fmask_load->instr, &fmask_load->def, 1, 32); nir_builder_instr_insert(b, &fmask_load->instr); nir_def *samples_identical = nir_ieq_imm(b, &fmask_load->def, 0); nir_def_replace(&intrin->def, samples_identical); nir_instr_free(&intrin->instr); } static bool lower_image_intrin(nir_builder *b, nir_intrinsic_instr *intrin, void *state) { const nir_lower_image_options *options = state; switch (intrin->intrinsic) { case nir_intrinsic_image_size: case nir_intrinsic_image_deref_size: case nir_intrinsic_bindless_image_size: if (options->lower_cube_size && nir_intrinsic_image_dim(intrin) == GLSL_SAMPLER_DIM_CUBE) { lower_cube_size(b, intrin); return true; } return false; case nir_intrinsic_image_load: case nir_intrinsic_image_deref_load: case nir_intrinsic_bindless_image_load: if (options->lower_to_fragment_mask_load_amd && nir_intrinsic_image_dim(intrin) == GLSL_SAMPLER_DIM_MS && /* Don't lower again. */ !(nir_intrinsic_access(intrin) & ACCESS_FMASK_LOWERED_AMD)) { lower_image_to_fragment_mask_load(b, intrin); return true; } return false; case nir_intrinsic_image_samples_identical: case nir_intrinsic_image_deref_samples_identical: case nir_intrinsic_bindless_image_samples_identical: if (options->lower_to_fragment_mask_load_amd && nir_intrinsic_image_dim(intrin) == GLSL_SAMPLER_DIM_MS) { lower_image_samples_identical_to_fragment_mask_load(b, intrin); return true; } return false; case nir_intrinsic_image_samples: case nir_intrinsic_image_deref_samples: case nir_intrinsic_bindless_image_samples: { if (options->lower_image_samples_to_one) { b->cursor = nir_after_instr(&intrin->instr); nir_def *samples = nir_imm_intN_t(b, 1, intrin->def.bit_size); nir_def_rewrite_uses(&intrin->def, samples); return true; } return false; } default: return false; } } bool nir_lower_image(nir_shader *nir, const nir_lower_image_options *options) { return nir_shader_intrinsics_pass(nir, lower_image_intrin, nir_metadata_control_flow, (void *)options); }