diff options
Diffstat (limited to 'src/panfrost/midgard/midgard_errata_lod.c')
| -rw-r--r-- | src/panfrost/midgard/midgard_errata_lod.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/panfrost/midgard/midgard_errata_lod.c b/src/panfrost/midgard/midgard_errata_lod.c new file mode 100644 index 00000000000..55e2b230cb6 --- /dev/null +++ b/src/panfrost/midgard/midgard_errata_lod.c @@ -0,0 +1,98 @@ +/* + * Copyright (C) 2019 Collabora, Ltd. + * + * 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 "compiler/nir/nir.h" +#include "compiler/nir/nir_builder.h" + +void midgard_nir_lod_errata(nir_shader *shader); + +/* Workarounds errata pertaining to early Midgard chips where the settings for + * min_lod/max_lod/lod_bias are ignored in the sampler descriptor when + * texturing with a textureLod instruction. The workaround is to load these + * constants in as system values and perform the bias/clamp in the shader. + */ + +static void +mir_lod_errata_body(nir_builder *b, nir_tex_instr *tex) +{ + /* The errata only applies to textureLod ("TEXGRD") */ + if (tex->op != nir_texop_txl) + return; + + /* Let's grab the sampler parameters */ + nir_intrinsic_instr *l = nir_intrinsic_instr_create(b->shader, + nir_intrinsic_load_sampler_lod_parameters_pan); + l->num_components = 3; + nir_ssa_dest_init(&l->instr, &l->dest, 3, 32, NULL); + + /* TODO: Indirect samplers, separate sampler objects XXX */ + nir_src idx = nir_src_for_ssa(nir_imm_int(b, tex->texture_index)); + nir_src_copy(&l->src[0], &idx, l); + + nir_builder_instr_insert(b, &l->instr); + nir_ssa_def *params = &l->dest.ssa; + + /* Extract the individual components */ + nir_ssa_def *min_lod = nir_channel(b, params, 0); + nir_ssa_def *max_lod = nir_channel(b, params, 1); + nir_ssa_def *lod_bias = nir_channel(b, params, 2); + + /* Rewrite the LOD with bias/clamps. Order sensitive. */ + for (unsigned i = 0; i < tex->num_srcs; i++) { + if (tex->src[i].src_type != nir_tex_src_lod) + continue; + + nir_ssa_def *lod = nir_ssa_for_src(b, tex->src[i].src, 1); + + nir_ssa_def *biased = nir_fadd(b, lod, lod_bias); + nir_ssa_def *clamped = nir_fmin(b, + nir_fmax(b, biased, min_lod), max_lod); + + nir_instr_rewrite_src(&tex->instr, &tex->src[i].src, + nir_src_for_ssa(clamped)); + } +} + +void +midgard_nir_lod_errata(nir_shader *shader) +{ + nir_foreach_function(function, shader) { + if (!function->impl) continue; + + nir_builder b; + nir_builder_init(&b, function->impl); + + nir_foreach_block(block, function->impl) { + nir_foreach_instr_safe(instr, block) { + if (instr->type != nir_instr_type_tex) continue; + + nir_tex_instr *tex = nir_instr_as_tex(instr); + b.cursor = nir_before_instr(instr); + mir_lod_errata_body(&b, tex); + } + } + + nir_metadata_preserve(function->impl, nir_metadata_block_index | nir_metadata_dominance); + + } +} |