/* * 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" #include "util/set.h" #include "util/hash_table.h" /* This file contains various little helpers for doing simple linking in * NIR. Eventually, we'll probably want a full-blown varying packing * implementation in here. Right now, it just deletes unused things. */ /** * Returns the bits in the inputs_read, outputs_written, or * system_values_read bitfield corresponding to this variable. */ static uint64_t get_variable_io_mask(nir_variable *var, gl_shader_stage stage) { if (var->data.location < 0) return 0; unsigned location = var->data.patch ? var->data.location - VARYING_SLOT_PATCH0 : var->data.location; assert(var->data.mode == nir_var_shader_in || var->data.mode == nir_var_shader_out || var->data.mode == nir_var_system_value); assert(var->data.location >= 0); const struct glsl_type *type = var->type; if (nir_is_per_vertex_io(var, stage)) { assert(glsl_type_is_array(type)); type = glsl_get_array_element(type); } unsigned slots = glsl_count_attribute_slots(type, false); return ((1ull << slots) - 1) << location; } static uint8_t get_num_components(nir_variable *var) { if (glsl_type_is_struct_or_ifc(glsl_without_array(var->type))) return 4; return glsl_get_vector_elements(glsl_without_array(var->type)); } static void tcs_add_output_reads(nir_shader *shader, uint64_t *read, uint64_t *patches_read) { nir_foreach_function(function, shader) { if (!function->impl) continue; nir_foreach_block(block, function->impl) { nir_foreach_instr(instr, block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); if (intrin->intrinsic != nir_intrinsic_load_deref) continue; nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]); if (deref->mode != nir_var_shader_out) continue; nir_variable *var = nir_deref_instr_get_variable(deref); for (unsigned i = 0; i < get_num_components(var); i++) { if (var->data.patch) { patches_read[var->data.location_frac + i] |= get_variable_io_mask(var, shader->info.stage); } else { read[var->data.location_frac + i] |= get_variable_io_mask(var, shader->info.stage); } } } } } } /** * Helper for removing unused shader I/O variables, by demoting them to global * variables (which may then by dead code eliminated). * * Example usage is: * * progress = nir_remove_unused_io_vars(producer, * &producer->outputs, * read, patches_read) || * progress; * * The "used" should be an array of 4 uint64_ts (probably of VARYING_BIT_*) * representing each .location_frac used. Note that for vector variables, * only the first channel (.location_frac) is examined for deciding if the * variable is used! */ bool nir_remove_unused_io_vars(nir_shader *shader, struct exec_list *var_list, uint64_t *used_by_other_stage, uint64_t *used_by_other_stage_patches) { bool progress = false; uint64_t *used; nir_foreach_variable_safe(var, var_list) { if (var->data.patch) used = used_by_other_stage_patches; else used = used_by_other_stage; if (var->data.location < VARYING_SLOT_VAR0 && var->data.location >= 0) continue; if (var->data.always_active_io) continue; if (var->data.explicit_xfb_buffer) continue; uint64_t other_stage = used[var->data.location_frac]; if (!(other_stage & get_variable_io_mask(var, shader->info.stage))) { /* This one is invalid, make it a global variable instead */ var->data.location = 0; var->data.mode = nir_var_shader_temp; exec_node_remove(&var->node); exec_list_push_tail(&shader->globals, &var->node); progress = true; } } if (progress) nir_fixup_deref_modes(shader); return progress; } bool nir_remove_unused_varyings(nir_shader *producer, nir_shader *consumer) { assert(producer->info.stage != MESA_SHADER_FRAGMENT); assert(consumer->info.stage != MESA_SHADER_VERTEX); uint64_t read[4] = { 0 }, written[4] = { 0 }; uint64_t patches_read[4] = { 0 }, patches_written[4] = { 0 }; nir_foreach_variable(var, &producer->outputs) { for (unsigned i = 0; i < get_num_components(var); i++) { if (var->data.patch) { patches_written[var->data.location_frac + i] |= get_variable_io_mask(var, producer->info.stage); } else { written[var->data.location_frac + i] |= get_variable_io_mask(var, producer->info.stage); } } } nir_foreach_variable(var, &consumer->inputs) { for (unsigned i = 0; i < get_num_components(var); i++) { if (var->data.patch) { patches_read[var->data.location_frac + i] |= get_variable_io_mask(var, consumer->info.stage); } else { read[var->data.location_frac + i] |= get_variable_io_mask(var, consumer->info.stage); } } } /* Each TCS invocation can read data written by other TCS invocations, * so even if the outputs are not used by the TES we must also make * sure they are not read by the TCS before demoting them to globals. */ if (producer->info.stage == MESA_SHADER_TESS_CTRL) tcs_add_output_reads(producer, read, patches_read); bool progress = false; progress = nir_remove_unused_io_vars(producer, &producer->outputs, read, patches_read); progress = nir_remove_unused_io_vars(consumer, &consumer->inputs, written, patches_written) || progress; return progress; } static uint8_t get_interp_type(nir_variable *var, const struct glsl_type *type, bool default_to_smooth_interp) { if (glsl_type_is_integer(type)) return INTERP_MODE_FLAT; else if (var->data.interpolation != INTERP_MODE_NONE) return var->data.interpolation; else if (default_to_smooth_interp) return INTERP_MODE_SMOOTH; else return INTERP_MODE_NONE; } #define INTERPOLATE_LOC_SAMPLE 0 #define INTERPOLATE_LOC_CENTROID 1 #define INTERPOLATE_LOC_CENTER 2 static uint8_t get_interp_loc(nir_variable *var) { if (var->data.sample) return INTERPOLATE_LOC_SAMPLE; else if (var->data.centroid) return INTERPOLATE_LOC_CENTROID; else return INTERPOLATE_LOC_CENTER; } static bool is_packing_supported_for_type(const struct glsl_type *type) { /* We ignore complex types such as arrays, matrices, structs and bitsizes * other then 32bit. All other vector types should have been split into * scalar variables by the lower_io_to_scalar pass. The only exception * should be OpenGL xfb varyings. * TODO: add support for more complex types? */ return glsl_type_is_scalar(type) && glsl_type_is_32bit(type); } struct assigned_comps { uint8_t comps; uint8_t interp_type; uint8_t interp_loc; bool is_32bit; }; /* Packing arrays and dual slot varyings is difficult so to avoid complex * algorithms this function just assigns them their existing location for now. * TODO: allow better packing of complex types. */ static void get_unmoveable_components_masks(struct exec_list *var_list, struct assigned_comps *comps, gl_shader_stage stage, bool default_to_smooth_interp) { nir_foreach_variable_safe(var, var_list) { assert(var->data.location >= 0); /* Only remap things that aren't built-ins. */ if (var->data.location >= VARYING_SLOT_VAR0 && var->data.location - VARYING_SLOT_VAR0 < MAX_VARYINGS_INCL_PATCH) { const struct glsl_type *type = var->type; if (nir_is_per_vertex_io(var, stage)) { assert(glsl_type_is_array(type)); type = glsl_get_array_element(type); } /* If we can pack this varying then don't mark the components as * used. */ if (is_packing_supported_for_type(type)) continue; unsigned location = var->data.location - VARYING_SLOT_VAR0; unsigned elements = glsl_type_is_vector_or_scalar(glsl_without_array(type)) ? glsl_get_vector_elements(glsl_without_array(type)) : 4; bool dual_slot = glsl_type_is_dual_slot(glsl_without_array(type)); unsigned slots = glsl_count_attribute_slots(type, false); unsigned dmul = glsl_type_is_64bit(glsl_without_array(type)) ? 2 : 1; unsigned comps_slot2 = 0; for (unsigned i = 0; i < slots; i++) { if (dual_slot) { if (i & 1) { comps[location + i].comps |= ((1 << comps_slot2) - 1); } else { unsigned num_comps = 4 - var->data.location_frac; comps_slot2 = (elements * dmul) - num_comps; /* Assume ARB_enhanced_layouts packing rules for doubles */ assert(var->data.location_frac == 0 || var->data.location_frac == 2); assert(comps_slot2 <= 4); comps[location + i].comps |= ((1 << num_comps) - 1) << var->data.location_frac; } } else { comps[location + i].comps |= ((1 << (elements * dmul)) - 1) << var->data.location_frac; } comps[location + i].interp_type = get_interp_type(var, type, default_to_smooth_interp); comps[location + i].interp_loc = get_interp_loc(var); comps[location + i].is_32bit = glsl_type_is_32bit(glsl_without_array(type)); } } } } struct varying_loc { uint8_t component; uint32_t location; }; static void mark_all_used_slots(nir_variable *var, uint64_t *slots_used, uint64_t slots_used_mask, unsigned num_slots) { unsigned loc_offset = var->data.patch ? VARYING_SLOT_PATCH0 : 0; slots_used[var->data.patch ? 1 : 0] |= slots_used_mask & BITFIELD64_RANGE(var->data.location - loc_offset, num_slots); } static void mark_used_slot(nir_variable *var, uint64_t *slots_used, unsigned offset) { unsigned loc_offset = var->data.patch ? VARYING_SLOT_PATCH0 : 0; slots_used[var->data.patch ? 1 : 0] |= BITFIELD64_BIT(var->data.location - loc_offset + offset); } static void remap_slots_and_components(struct exec_list *var_list, gl_shader_stage stage, struct varying_loc (*remap)[4], uint64_t *slots_used, uint64_t *out_slots_read, uint32_t *p_slots_used, uint32_t *p_out_slots_read) { uint64_t out_slots_read_tmp[2] = {0}; uint64_t slots_used_tmp[2] = {0}; /* We don't touch builtins so just copy the bitmask */ slots_used_tmp[0] = *slots_used & BITFIELD64_RANGE(0, VARYING_SLOT_VAR0); nir_foreach_variable(var, var_list) { assert(var->data.location >= 0); /* Only remap things that aren't built-ins */ if (var->data.location >= VARYING_SLOT_VAR0 && var->data.location - VARYING_SLOT_VAR0 < MAX_VARYINGS_INCL_PATCH) { const struct glsl_type *type = var->type; if (nir_is_per_vertex_io(var, stage)) { assert(glsl_type_is_array(type)); type = glsl_get_array_element(type); } unsigned num_slots = glsl_count_attribute_slots(type, false); bool used_across_stages = false; bool outputs_read = false; unsigned location = var->data.location - VARYING_SLOT_VAR0; struct varying_loc *new_loc = &remap[location][var->data.location_frac]; unsigned loc_offset = var->data.patch ? VARYING_SLOT_PATCH0 : 0; uint64_t used = var->data.patch ? *p_slots_used : *slots_used; uint64_t outs_used = var->data.patch ? *p_out_slots_read : *out_slots_read; uint64_t slots = BITFIELD64_RANGE(var->data.location - loc_offset, num_slots); if (slots & used) used_across_stages = true; if (slots & outs_used) outputs_read = true; if (new_loc->location) { var->data.location = new_loc->location; var->data.location_frac = new_loc->component; } if (var->data.always_active_io) { /* We can't apply link time optimisations (specifically array * splitting) to these so we need to copy the existing mask * otherwise we will mess up the mask for things like partially * marked arrays. */ if (used_across_stages) mark_all_used_slots(var, slots_used_tmp, used, num_slots); if (outputs_read) { mark_all_used_slots(var, out_slots_read_tmp, outs_used, num_slots); } } else { for (unsigned i = 0; i < num_slots; i++) { if (used_across_stages) mark_used_slot(var, slots_used_tmp, i); if (outputs_read) mark_used_slot(var, out_slots_read_tmp, i); } } } } *slots_used = slots_used_tmp[0]; *out_slots_read = out_slots_read_tmp[0]; *p_slots_used = slots_used_tmp[1]; *p_out_slots_read = out_slots_read_tmp[1]; } struct varying_component { nir_variable *var; uint8_t interp_type; uint8_t interp_loc; bool is_32bit; bool is_patch; bool initialised; }; static int cmp_varying_component(const void *comp1_v, const void *comp2_v) { struct varying_component *comp1 = (struct varying_component *) comp1_v; struct varying_component *comp2 = (struct varying_component *) comp2_v; /* We want patches to be order at the end of the array */ if (comp1->is_patch != comp2->is_patch) return comp1->is_patch ? 1 : -1; /* We can only pack varyings with matching interpolation types so group * them together. */ if (comp1->interp_type != comp2->interp_type) return comp1->interp_type - comp2->interp_type; /* Interpolation loc must match also. */ if (comp1->interp_loc != comp2->interp_loc) return comp1->interp_loc - comp2->interp_loc; /* If everything else matches just use the original location to sort */ return comp1->var->data.location - comp2->var->data.location; } static void gather_varying_component_info(nir_shader *consumer, struct varying_component **varying_comp_info, unsigned *varying_comp_info_size, bool default_to_smooth_interp) { unsigned store_varying_info_idx[MAX_VARYINGS_INCL_PATCH][4] = {{0}}; unsigned num_of_comps_to_pack = 0; /* Count the number of varying that can be packed and create a mapping * of those varyings to the array we will pass to qsort. */ nir_foreach_variable(var, &consumer->inputs) { /* Only remap things that aren't builtins. */ if (var->data.location >= VARYING_SLOT_VAR0 && var->data.location - VARYING_SLOT_VAR0 < MAX_VARYINGS_INCL_PATCH) { /* We can't repack xfb varyings. */ if (var->data.always_active_io) continue; const struct glsl_type *type = var->type; if (nir_is_per_vertex_io(var, consumer->info.stage)) { assert(glsl_type_is_array(type)); type = glsl_get_array_element(type); } if (!is_packing_supported_for_type(type)) continue; unsigned loc = var->data.location - VARYING_SLOT_VAR0; store_varying_info_idx[loc][var->data.location_frac] = ++num_of_comps_to_pack; } } *varying_comp_info_size = num_of_comps_to_pack; *varying_comp_info = rzalloc_array(NULL, struct varying_component, num_of_comps_to_pack); nir_function_impl *impl = nir_shader_get_entrypoint(consumer); /* Walk over the shader and populate the varying component info array */ nir_foreach_block(block, impl) { nir_foreach_instr(instr, block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); if (intr->intrinsic != nir_intrinsic_load_deref && intr->intrinsic != nir_intrinsic_interp_deref_at_centroid && intr->intrinsic != nir_intrinsic_interp_deref_at_sample && intr->intrinsic != nir_intrinsic_interp_deref_at_offset) continue; nir_deref_instr *deref = nir_src_as_deref(intr->src[0]); if (deref->mode != nir_var_shader_in) continue; /* We only remap things that aren't builtins. */ nir_variable *in_var = nir_deref_instr_get_variable(deref); if (in_var->data.location < VARYING_SLOT_VAR0) continue; unsigned location = in_var->data.location - VARYING_SLOT_VAR0; if (location >= MAX_VARYINGS_INCL_PATCH) continue; unsigned var_info_idx = store_varying_info_idx[location][in_var->data.location_frac]; if (!var_info_idx) continue; struct varying_component *vc_info = &(*varying_comp_info)[var_info_idx-1]; if (!vc_info->initialised) { const struct glsl_type *type = in_var->type; if (nir_is_per_vertex_io(in_var, consumer->info.stage)) { assert(glsl_type_is_array(type)); type = glsl_get_array_element(type); } vc_info->var = in_var; vc_info->interp_type = get_interp_type(in_var, type, default_to_smooth_interp); vc_info->interp_loc = get_interp_loc(in_var); vc_info->is_32bit = glsl_type_is_32bit(type); vc_info->is_patch = in_var->data.patch; } } } } static void assign_remap_locations(struct varying_loc (*remap)[4], struct assigned_comps *assigned_comps, struct varying_component *info, unsigned *cursor, unsigned *comp, unsigned max_location) { unsigned tmp_cursor = *cursor; unsigned tmp_comp = *comp; for (; tmp_cursor < max_location; tmp_cursor++) { if (assigned_comps[tmp_cursor].comps) { /* We can only pack varyings with matching interpolation types, * interpolation loc must match also. * TODO: i965 can handle interpolation locations that don't match, * but the radeonsi nir backend handles everything as vec4s and so * expects this to be the same for all components. We could make this * check driver specfific or drop it if NIR ever become the only * radeonsi backend. */ if (assigned_comps[tmp_cursor].interp_type != info->interp_type || assigned_comps[tmp_cursor].interp_loc != info->interp_loc) { tmp_comp = 0; continue; } /* We can only pack varyings with matching types, and the current * algorithm only supports packing 32-bit. */ if (!assigned_comps[tmp_cursor].is_32bit) { tmp_comp = 0; continue; } while (tmp_comp < 4 && (assigned_comps[tmp_cursor].comps & (1 << tmp_comp))) { tmp_comp++; } } if (tmp_comp == 4) { tmp_comp = 0; continue; } unsigned location = info->var->data.location - VARYING_SLOT_VAR0; /* Once we have assigned a location mark it as used */ assigned_comps[tmp_cursor].comps |= (1 << tmp_comp); assigned_comps[tmp_cursor].interp_type = info->interp_type; assigned_comps[tmp_cursor].interp_loc = info->interp_loc; assigned_comps[tmp_cursor].is_32bit = info->is_32bit; /* Assign remap location */ remap[location][info->var->data.location_frac].component = tmp_comp++; remap[location][info->var->data.location_frac].location = tmp_cursor + VARYING_SLOT_VAR0; break; } *cursor = tmp_cursor; *comp = tmp_comp; } /* If there are empty components in the slot compact the remaining components * as close to component 0 as possible. This will make it easier to fill the * empty components with components from a different slot in a following pass. */ static void compact_components(nir_shader *producer, nir_shader *consumer, struct assigned_comps *assigned_comps, bool default_to_smooth_interp) { struct exec_list *input_list = &consumer->inputs; struct exec_list *output_list = &producer->outputs; struct varying_loc remap[MAX_VARYINGS_INCL_PATCH][4] = {{{0}, {0}}}; struct varying_component *varying_comp_info; unsigned varying_comp_info_size; /* Gather varying component info */ gather_varying_component_info(consumer, &varying_comp_info, &varying_comp_info_size, default_to_smooth_interp); /* Sort varying components. */ qsort(varying_comp_info, varying_comp_info_size, sizeof(struct varying_component), cmp_varying_component); unsigned cursor = 0; unsigned comp = 0; /* Set the remap array based on the sorted components */ for (unsigned i = 0; i < varying_comp_info_size; i++ ) { struct varying_component *info = &varying_comp_info[i]; assert(info->is_patch || cursor < MAX_VARYING); if (info->is_patch) { /* The list should be sorted with all non-patch inputs first followed * by patch inputs. When we hit our first patch input, we need to * reset the cursor to MAX_VARYING so we put them in the right slot. */ if (cursor < MAX_VARYING) { cursor = MAX_VARYING; comp = 0; } assign_remap_locations(remap, assigned_comps, info, &cursor, &comp, MAX_VARYINGS_INCL_PATCH); } else { assign_remap_locations(remap, assigned_comps, info, &cursor, &comp, MAX_VARYING); /* Check if we failed to assign a remap location. This can happen if * for example there are a bunch of unmovable components with * mismatching interpolation types causing us to skip over locations * that would have been useful for packing later components. * The solution is to iterate over the locations again (this should * happen very rarely in practice). */ if (cursor == MAX_VARYING) { cursor = 0; comp = 0; assign_remap_locations(remap, assigned_comps, info, &cursor, &comp, MAX_VARYING); } } } ralloc_free(varying_comp_info); uint64_t zero = 0; uint32_t zero32 = 0; remap_slots_and_components(input_list, consumer->info.stage, remap, &consumer->info.inputs_read, &zero, &consumer->info.patch_inputs_read, &zero32); remap_slots_and_components(output_list, producer->info.stage, remap, &producer->info.outputs_written, &producer->info.outputs_read, &producer->info.patch_outputs_written, &producer->info.patch_outputs_read); } /* We assume that this has been called more-or-less directly after * remove_unused_varyings. At this point, all of the varyings that we * aren't going to be using have been completely removed and the * inputs_read and outputs_written fields in nir_shader_info reflect * this. Therefore, the total set of valid slots is the OR of the two * sets of varyings; this accounts for varyings which one side may need * to read/write even if the other doesn't. This can happen if, for * instance, an array is used indirectly from one side causing it to be * unsplittable but directly from the other. */ void nir_compact_varyings(nir_shader *producer, nir_shader *consumer, bool default_to_smooth_interp) { assert(producer->info.stage != MESA_SHADER_FRAGMENT); assert(consumer->info.stage != MESA_SHADER_VERTEX); struct assigned_comps assigned_comps[MAX_VARYINGS_INCL_PATCH] = {{0}}; get_unmoveable_components_masks(&producer->outputs, assigned_comps, producer->info.stage, default_to_smooth_interp); get_unmoveable_components_masks(&consumer->inputs, assigned_comps, consumer->info.stage, default_to_smooth_interp); compact_components(producer, consumer, assigned_comps, default_to_smooth_interp); } /* * Mark XFB varyings as always_active_io in the consumer so the linking opts * don't touch them. */ void nir_link_xfb_varyings(nir_shader *producer, nir_shader *consumer) { nir_variable *input_vars[MAX_VARYING] = { 0 }; nir_foreach_variable(var, &consumer->inputs) { if (var->data.location >= VARYING_SLOT_VAR0 && var->data.location - VARYING_SLOT_VAR0 < MAX_VARYING) { unsigned location = var->data.location - VARYING_SLOT_VAR0; input_vars[location] = var; } } nir_foreach_variable(var, &producer->outputs) { if (var->data.location >= VARYING_SLOT_VAR0 && var->data.location - VARYING_SLOT_VAR0 < MAX_VARYING) { if (!var->data.always_active_io) continue; unsigned location = var->data.location - VARYING_SLOT_VAR0; if (input_vars[location]) { input_vars[location]->data.always_active_io = true; } } } } static bool does_varying_match(nir_variable *out_var, nir_variable *in_var) { return in_var->data.location == out_var->data.location && in_var->data.location_frac == out_var->data.location_frac; } static nir_variable * get_matching_input_var(nir_shader *consumer, nir_variable *out_var) { nir_foreach_variable(var, &consumer->inputs) { if (does_varying_match(out_var, var)) return var; } return NULL; } static bool can_replace_varying(nir_variable *out_var) { /* Skip types that require more complex handling. * TODO: add support for these types. */ if (glsl_type_is_array(out_var->type) || glsl_type_is_dual_slot(out_var->type) || glsl_type_is_matrix(out_var->type) || glsl_type_is_struct_or_ifc(out_var->type)) return false; /* Limit this pass to scalars for now to keep things simple. Most varyings * should have been lowered to scalars at this point anyway. */ if (!glsl_type_is_scalar(out_var->type)) return false; if (out_var->data.location < VARYING_SLOT_VAR0 || out_var->data.location - VARYING_SLOT_VAR0 >= MAX_VARYING) return false; return true; } static bool replace_constant_input(nir_shader *shader, nir_intrinsic_instr *store_intr) { nir_function_impl *impl = nir_shader_get_entrypoint(shader); nir_builder b; nir_builder_init(&b, impl); nir_variable *out_var = nir_deref_instr_get_variable(nir_src_as_deref(store_intr->src[0])); bool progress = false; nir_foreach_block(block, impl) { nir_foreach_instr(instr, block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); if (intr->intrinsic != nir_intrinsic_load_deref) continue; nir_deref_instr *in_deref = nir_src_as_deref(intr->src[0]); if (in_deref->mode != nir_var_shader_in) continue; nir_variable *in_var = nir_deref_instr_get_variable(in_deref); if (!does_varying_match(out_var, in_var)) continue; b.cursor = nir_before_instr(instr); nir_load_const_instr *out_const = nir_instr_as_load_const(store_intr->src[1].ssa->parent_instr); /* Add new const to replace the input */ nir_ssa_def *nconst = nir_build_imm(&b, store_intr->num_components, intr->dest.ssa.bit_size, out_const->value); nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(nconst)); progress = true; } } return progress; } static bool replace_duplicate_input(nir_shader *shader, nir_variable *input_var, nir_intrinsic_instr *dup_store_intr) { assert(input_var); nir_function_impl *impl = nir_shader_get_entrypoint(shader); nir_builder b; nir_builder_init(&b, impl); nir_variable *dup_out_var = nir_deref_instr_get_variable(nir_src_as_deref(dup_store_intr->src[0])); bool progress = false; nir_foreach_block(block, impl) { nir_foreach_instr(instr, block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); if (intr->intrinsic != nir_intrinsic_load_deref) continue; nir_deref_instr *in_deref = nir_src_as_deref(intr->src[0]); if (in_deref->mode != nir_var_shader_in) continue; nir_variable *in_var = nir_deref_instr_get_variable(in_deref); if (!does_varying_match(dup_out_var, in_var) || in_var->data.interpolation != input_var->data.interpolation || get_interp_loc(in_var) != get_interp_loc(input_var)) continue; b.cursor = nir_before_instr(instr); nir_ssa_def *load = nir_load_var(&b, input_var); nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(load)); progress = true; } } return progress; } bool nir_link_opt_varyings(nir_shader *producer, nir_shader *consumer) { /* TODO: Add support for more shader stage combinations */ if (consumer->info.stage != MESA_SHADER_FRAGMENT || (producer->info.stage != MESA_SHADER_VERTEX && producer->info.stage != MESA_SHADER_TESS_EVAL)) return false; bool progress = false; nir_function_impl *impl = nir_shader_get_entrypoint(producer); struct hash_table *varying_values = _mesa_pointer_hash_table_create(NULL); /* If we find a store in the last block of the producer we can be sure this * is the only possible value for this output. */ nir_block *last_block = nir_impl_last_block(impl); nir_foreach_instr_reverse(instr, last_block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); if (intr->intrinsic != nir_intrinsic_store_deref) continue; nir_deref_instr *out_deref = nir_src_as_deref(intr->src[0]); if (out_deref->mode != nir_var_shader_out) continue; nir_variable *out_var = nir_deref_instr_get_variable(out_deref); if (!can_replace_varying(out_var)) continue; if (intr->src[1].ssa->parent_instr->type == nir_instr_type_load_const) { progress |= replace_constant_input(consumer, intr); } else { struct hash_entry *entry = _mesa_hash_table_search(varying_values, intr->src[1].ssa); if (entry) { progress |= replace_duplicate_input(consumer, (nir_variable *) entry->data, intr); } else { nir_variable *in_var = get_matching_input_var(consumer, out_var); if (in_var) { _mesa_hash_table_insert(varying_values, intr->src[1].ssa, in_var); } } } } _mesa_hash_table_destroy(varying_values, NULL); return progress; }