| /* |
| * Copyright © 2015 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" |
| |
| /** |
| * @file |
| * |
| * This pass combines separate clip and cull distance arrays into a |
| * single array that contains both. Clip distances come first, then |
| * cull distances. It also populates nir_shader_info with the size |
| * of the original arrays so the driver knows which are which. |
| */ |
| |
| /** |
| * Get the length of the clip/cull distance array, looking past |
| * any interface block arrays. |
| */ |
| static unsigned |
| get_unwrapped_array_length(nir_shader *nir, nir_variable *var) |
| { |
| if (!var) |
| return 0; |
| |
| /* Unwrap GS input and TCS input/output interfaces. We want the |
| * underlying clip/cull distance array length, not the per-vertex |
| * array length. |
| */ |
| const struct glsl_type *type = var->type; |
| if (nir_is_per_vertex_io(var, nir->info.stage)) |
| type = glsl_get_array_element(type); |
| |
| assert(glsl_type_is_array(type)); |
| |
| return glsl_get_length(type); |
| } |
| |
| /** |
| * Update the type of the combined array (including interface block nesting). |
| */ |
| static void |
| update_type(nir_variable *var, gl_shader_stage stage, unsigned length) |
| { |
| const struct glsl_type *type = glsl_array_type(glsl_float_type(), length); |
| |
| if (nir_is_per_vertex_io(var, stage)) |
| type = glsl_array_type(type, glsl_get_length(var->type)); |
| |
| var->type = type; |
| } |
| |
| /** |
| * Rewrite any clip/cull distances to refer to the new combined array. |
| */ |
| static void |
| rewrite_references(nir_instr *instr, |
| nir_variable *combined, |
| unsigned cull_offset) |
| { |
| if (instr->type != nir_instr_type_intrinsic) |
| return; |
| |
| nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); |
| |
| /* copy_var needs to be lowered to load/store before calling this pass */ |
| assert(intrin->intrinsic != nir_intrinsic_copy_var); |
| |
| if (intrin->intrinsic != nir_intrinsic_load_var && |
| intrin->intrinsic != nir_intrinsic_store_var) |
| return; |
| |
| nir_deref_var *var_ref = intrin->variables[0]; |
| if (var_ref->var->data.mode != combined->data.mode) |
| return; |
| |
| if (var_ref->var->data.location != VARYING_SLOT_CLIP_DIST0 && |
| var_ref->var->data.location != VARYING_SLOT_CULL_DIST0) |
| return; |
| |
| /* Update types along the deref chain */ |
| const struct glsl_type *type = combined->type; |
| nir_deref *deref = &var_ref->deref; |
| while (deref) { |
| deref->type = type; |
| deref = deref->child; |
| type = glsl_get_array_element(type); |
| } |
| |
| /* For cull distances, add an offset to the array index */ |
| if (var_ref->var->data.location == VARYING_SLOT_CULL_DIST0) { |
| nir_deref *tail = nir_deref_tail(&intrin->variables[0]->deref); |
| nir_deref_array *array_ref = nir_deref_as_array(tail); |
| |
| array_ref->base_offset += cull_offset; |
| } |
| |
| /* Point the deref at the combined array */ |
| var_ref->var = combined; |
| |
| /* There's no need to update writemasks; it's a scalar array. */ |
| } |
| |
| static bool |
| combine_clip_cull(nir_shader *nir, |
| struct exec_list *vars, |
| bool store_info) |
| { |
| nir_variable *cull = NULL; |
| nir_variable *clip = NULL; |
| bool progress = false; |
| |
| nir_foreach_variable(var, vars) { |
| if (var->data.location == VARYING_SLOT_CLIP_DIST0) |
| clip = var; |
| |
| if (var->data.location == VARYING_SLOT_CULL_DIST0) |
| cull = var; |
| } |
| |
| const unsigned clip_array_size = get_unwrapped_array_length(nir, clip); |
| const unsigned cull_array_size = get_unwrapped_array_length(nir, cull); |
| |
| if (store_info) { |
| nir->info.clip_distance_array_size = clip_array_size; |
| nir->info.cull_distance_array_size = cull_array_size; |
| } |
| |
| if (clip) |
| clip->data.compact = true; |
| |
| if (cull) |
| cull->data.compact = true; |
| |
| if (cull_array_size > 0) { |
| if (clip_array_size == 0) { |
| /* No clip distances, just change the cull distance location */ |
| cull->data.location = VARYING_SLOT_CLIP_DIST0; |
| } else { |
| /* Turn the ClipDistance array into a combined one */ |
| update_type(clip, nir->info.stage, clip_array_size + cull_array_size); |
| |
| /* Rewrite CullDistance to reference the combined array */ |
| nir_foreach_function(function, nir) { |
| if (function->impl) { |
| nir_foreach_block(block, function->impl) { |
| nir_foreach_instr(instr, block) { |
| rewrite_references(instr, clip, clip_array_size); |
| } |
| } |
| } |
| } |
| |
| /* Delete the old CullDistance variable */ |
| exec_node_remove(&cull->node); |
| ralloc_free(cull); |
| } |
| |
| nir_foreach_function(function, nir) { |
| if (function->impl) { |
| nir_metadata_preserve(function->impl, |
| nir_metadata_block_index | |
| nir_metadata_dominance); |
| } |
| } |
| progress = true; |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_lower_clip_cull_distance_arrays(nir_shader *nir) |
| { |
| bool progress = false; |
| |
| if (nir->info.stage <= MESA_SHADER_GEOMETRY) |
| progress |= combine_clip_cull(nir, &nir->outputs, true); |
| |
| if (nir->info.stage > MESA_SHADER_VERTEX) |
| progress |= combine_clip_cull(nir, &nir->inputs, false); |
| |
| return progress; |
| } |