/* * Copyright © 2018 Valve 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" /* This pass computes for each ssa definition if it is uniform. * That is, the variable has the same value for all invocations * of the group. * * This divergence analysis pass expects the shader to be in LCSSA-form. * * This algorithm implements "The Simple Divergence Analysis" from * Diogo Sampaio, Rafael De Souza, Sylvain Collange, Fernando Magno Quintão Pereira. * Divergence Analysis. ACM Transactions on Programming Languages and Systems (TOPLAS), * ACM, 2013, 35 (4), pp.13:1-13:36. <10.1145/2523815>. */ static bool visit_cf_list(bool *divergent, struct exec_list *list, nir_divergence_options options, gl_shader_stage stage); static bool visit_alu(bool *divergent, nir_alu_instr *instr) { if (divergent[instr->dest.dest.ssa.index]) return false; unsigned num_src = nir_op_infos[instr->op].num_inputs; for (unsigned i = 0; i < num_src; i++) { if (divergent[instr->src[i].src.ssa->index]) { divergent[instr->dest.dest.ssa.index] = true; return true; } } return false; } static bool visit_intrinsic(bool *divergent, nir_intrinsic_instr *instr, nir_divergence_options options, gl_shader_stage stage) { if (!nir_intrinsic_infos[instr->intrinsic].has_dest) return false; if (divergent[instr->dest.ssa.index]) return false; bool is_divergent = false; switch (instr->intrinsic) { /* Intrinsics which are always uniform */ case nir_intrinsic_shader_clock: case nir_intrinsic_ballot: case nir_intrinsic_read_invocation: case nir_intrinsic_read_first_invocation: case nir_intrinsic_vote_any: case nir_intrinsic_vote_all: case nir_intrinsic_vote_feq: case nir_intrinsic_vote_ieq: case nir_intrinsic_load_work_dim: case nir_intrinsic_load_work_group_id: case nir_intrinsic_load_num_work_groups: case nir_intrinsic_load_local_group_size: case nir_intrinsic_load_subgroup_id: case nir_intrinsic_load_num_subgroups: case nir_intrinsic_load_subgroup_size: case nir_intrinsic_load_subgroup_eq_mask: case nir_intrinsic_load_subgroup_ge_mask: case nir_intrinsic_load_subgroup_gt_mask: case nir_intrinsic_load_subgroup_le_mask: case nir_intrinsic_load_subgroup_lt_mask: case nir_intrinsic_first_invocation: case nir_intrinsic_load_base_instance: case nir_intrinsic_load_base_vertex: case nir_intrinsic_load_first_vertex: case nir_intrinsic_load_draw_id: case nir_intrinsic_load_is_indexed_draw: case nir_intrinsic_load_viewport_scale: case nir_intrinsic_load_alpha_ref_float: case nir_intrinsic_load_user_clip_plane: case nir_intrinsic_load_viewport_x_scale: case nir_intrinsic_load_viewport_y_scale: case nir_intrinsic_load_viewport_z_scale: case nir_intrinsic_load_viewport_offset: case nir_intrinsic_load_viewport_z_offset: case nir_intrinsic_load_blend_const_color_a_float: case nir_intrinsic_load_blend_const_color_b_float: case nir_intrinsic_load_blend_const_color_g_float: case nir_intrinsic_load_blend_const_color_r_float: case nir_intrinsic_load_blend_const_color_rgba: case nir_intrinsic_load_blend_const_color_aaaa8888_unorm: case nir_intrinsic_load_blend_const_color_rgba8888_unorm: is_divergent = false; break; /* Intrinsics with divergence depending on shader stage and hardware */ case nir_intrinsic_load_input: is_divergent = divergent[instr->src[0].ssa->index]; if (stage == MESA_SHADER_FRAGMENT) is_divergent |= !(options & nir_divergence_single_prim_per_subgroup); else if (stage == MESA_SHADER_TESS_EVAL) is_divergent |= !(options & nir_divergence_single_patch_per_tes_subgroup); else is_divergent = true; break; case nir_intrinsic_load_output: assert(stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_FRAGMENT); is_divergent = divergent[instr->src[0].ssa->index]; if (stage == MESA_SHADER_TESS_CTRL) is_divergent |= !(options & nir_divergence_single_patch_per_tcs_subgroup); else is_divergent = true; break; case nir_intrinsic_load_layer_id: case nir_intrinsic_load_front_face: assert(stage == MESA_SHADER_FRAGMENT); is_divergent = !(options & nir_divergence_single_prim_per_subgroup); break; case nir_intrinsic_load_view_index: assert(stage != MESA_SHADER_COMPUTE && stage != MESA_SHADER_KERNEL); if (options & nir_divergence_view_index_uniform) is_divergent = false; else if (stage == MESA_SHADER_FRAGMENT) is_divergent = !(options & nir_divergence_single_prim_per_subgroup); break; case nir_intrinsic_load_fs_input_interp_deltas: assert(stage == MESA_SHADER_FRAGMENT); is_divergent = divergent[instr->src[0].ssa->index]; is_divergent |= !(options & nir_divergence_single_prim_per_subgroup); break; case nir_intrinsic_load_primitive_id: if (stage == MESA_SHADER_FRAGMENT) is_divergent = !(options & nir_divergence_single_prim_per_subgroup); else if (stage == MESA_SHADER_TESS_CTRL) is_divergent = !(options & nir_divergence_single_patch_per_tcs_subgroup); else if (stage == MESA_SHADER_TESS_EVAL) is_divergent = !(options & nir_divergence_single_patch_per_tes_subgroup); else unreachable("Invalid stage for load_primitive_id"); break; case nir_intrinsic_load_tess_level_inner: case nir_intrinsic_load_tess_level_outer: if (stage == MESA_SHADER_TESS_CTRL) is_divergent = !(options & nir_divergence_single_patch_per_tcs_subgroup); else if (stage == MESA_SHADER_TESS_EVAL) is_divergent = !(options & nir_divergence_single_patch_per_tes_subgroup); else unreachable("Invalid stage for load_primitive_tess_level_*"); break; case nir_intrinsic_load_patch_vertices_in: if (stage == MESA_SHADER_TESS_EVAL) is_divergent = !(options & nir_divergence_single_patch_per_tes_subgroup); else assert(stage == MESA_SHADER_TESS_CTRL); break; /* Clustered reductions are uniform if cluster_size == subgroup_size or * the source is uniform and the operation is invariant. * Inclusive scans are uniform if * the source is uniform and the operation is invariant */ case nir_intrinsic_reduce: if (nir_intrinsic_cluster_size(instr) == 0) return false; /* fallthrough */ case nir_intrinsic_inclusive_scan: { nir_op op = nir_intrinsic_reduction_op(instr); is_divergent = divergent[instr->src[0].ssa->index]; if (op != nir_op_umin && op != nir_op_imin && op != nir_op_fmin && op != nir_op_umax && op != nir_op_imax && op != nir_op_fmax && op != nir_op_iand && op != nir_op_ior) is_divergent = true; break; } /* Intrinsics with divergence depending on sources */ case nir_intrinsic_ballot_bitfield_extract: case nir_intrinsic_ballot_find_lsb: case nir_intrinsic_ballot_find_msb: case nir_intrinsic_ballot_bit_count_reduce: case nir_intrinsic_shuffle_xor: case nir_intrinsic_shuffle_up: case nir_intrinsic_shuffle_down: case nir_intrinsic_quad_broadcast: case nir_intrinsic_quad_swap_horizontal: case nir_intrinsic_quad_swap_vertical: case nir_intrinsic_quad_swap_diagonal: case nir_intrinsic_load_deref: case nir_intrinsic_load_ubo: case nir_intrinsic_load_ssbo: case nir_intrinsic_load_shared: case nir_intrinsic_load_global: case nir_intrinsic_load_uniform: case nir_intrinsic_load_push_constant: case nir_intrinsic_load_constant: case nir_intrinsic_load_sample_pos_from_id: case nir_intrinsic_load_kernel_input: case nir_intrinsic_image_load: case nir_intrinsic_image_deref_load: case nir_intrinsic_bindless_image_load: case nir_intrinsic_image_samples: case nir_intrinsic_image_deref_samples: case nir_intrinsic_bindless_image_samples: case nir_intrinsic_get_buffer_size: case nir_intrinsic_image_size: case nir_intrinsic_image_deref_size: case nir_intrinsic_bindless_image_size: case nir_intrinsic_copy_deref: case nir_intrinsic_deref_buffer_array_length: case nir_intrinsic_vulkan_resource_index: case nir_intrinsic_vulkan_resource_reindex: case nir_intrinsic_load_vulkan_descriptor: case nir_intrinsic_atomic_counter_read: case nir_intrinsic_atomic_counter_read_deref: case nir_intrinsic_quad_swizzle_amd: case nir_intrinsic_masked_swizzle_amd: { unsigned num_srcs = nir_intrinsic_infos[instr->intrinsic].num_srcs; for (unsigned i = 0; i < num_srcs; i++) { if (divergent[instr->src[i].ssa->index]) { is_divergent = true; break; } } break; } case nir_intrinsic_shuffle: is_divergent = divergent[instr->src[0].ssa->index] && divergent[instr->src[1].ssa->index]; break; /* Intrinsics which are always divergent */ case nir_intrinsic_load_color0: case nir_intrinsic_load_color1: case nir_intrinsic_load_param: case nir_intrinsic_load_sample_id: case nir_intrinsic_load_sample_id_no_per_sample: case nir_intrinsic_load_sample_mask_in: case nir_intrinsic_load_interpolated_input: case nir_intrinsic_load_barycentric_pixel: case nir_intrinsic_load_barycentric_centroid: case nir_intrinsic_load_barycentric_sample: case nir_intrinsic_load_barycentric_at_sample: case nir_intrinsic_load_barycentric_at_offset: case nir_intrinsic_interp_deref_at_offset: case nir_intrinsic_interp_deref_at_sample: case nir_intrinsic_interp_deref_at_centroid: case nir_intrinsic_load_tess_coord: case nir_intrinsic_load_point_coord: case nir_intrinsic_load_frag_coord: case nir_intrinsic_load_sample_pos: case nir_intrinsic_load_vertex_id_zero_base: case nir_intrinsic_load_vertex_id: case nir_intrinsic_load_per_vertex_input: case nir_intrinsic_load_per_vertex_output: case nir_intrinsic_load_instance_id: case nir_intrinsic_load_invocation_id: case nir_intrinsic_load_local_invocation_id: case nir_intrinsic_load_local_invocation_index: case nir_intrinsic_load_global_invocation_id: case nir_intrinsic_load_global_invocation_index: case nir_intrinsic_load_subgroup_invocation: case nir_intrinsic_load_helper_invocation: case nir_intrinsic_is_helper_invocation: case nir_intrinsic_load_scratch: case nir_intrinsic_deref_atomic_add: case nir_intrinsic_deref_atomic_imin: case nir_intrinsic_deref_atomic_umin: case nir_intrinsic_deref_atomic_imax: case nir_intrinsic_deref_atomic_umax: case nir_intrinsic_deref_atomic_and: case nir_intrinsic_deref_atomic_or: case nir_intrinsic_deref_atomic_xor: case nir_intrinsic_deref_atomic_exchange: case nir_intrinsic_deref_atomic_comp_swap: case nir_intrinsic_deref_atomic_fadd: case nir_intrinsic_deref_atomic_fmin: case nir_intrinsic_deref_atomic_fmax: case nir_intrinsic_deref_atomic_fcomp_swap: case nir_intrinsic_ssbo_atomic_add: case nir_intrinsic_ssbo_atomic_imin: case nir_intrinsic_ssbo_atomic_umin: case nir_intrinsic_ssbo_atomic_imax: case nir_intrinsic_ssbo_atomic_umax: case nir_intrinsic_ssbo_atomic_and: case nir_intrinsic_ssbo_atomic_or: case nir_intrinsic_ssbo_atomic_xor: case nir_intrinsic_ssbo_atomic_exchange: case nir_intrinsic_ssbo_atomic_comp_swap: case nir_intrinsic_ssbo_atomic_fadd: case nir_intrinsic_ssbo_atomic_fmax: case nir_intrinsic_ssbo_atomic_fmin: case nir_intrinsic_ssbo_atomic_fcomp_swap: case nir_intrinsic_image_deref_atomic_add: case nir_intrinsic_image_deref_atomic_imin: case nir_intrinsic_image_deref_atomic_umin: case nir_intrinsic_image_deref_atomic_imax: case nir_intrinsic_image_deref_atomic_umax: case nir_intrinsic_image_deref_atomic_and: case nir_intrinsic_image_deref_atomic_or: case nir_intrinsic_image_deref_atomic_xor: case nir_intrinsic_image_deref_atomic_exchange: case nir_intrinsic_image_deref_atomic_comp_swap: case nir_intrinsic_image_deref_atomic_fadd: case nir_intrinsic_image_atomic_add: case nir_intrinsic_image_atomic_imin: case nir_intrinsic_image_atomic_umin: case nir_intrinsic_image_atomic_imax: case nir_intrinsic_image_atomic_umax: case nir_intrinsic_image_atomic_and: case nir_intrinsic_image_atomic_or: case nir_intrinsic_image_atomic_xor: case nir_intrinsic_image_atomic_exchange: case nir_intrinsic_image_atomic_comp_swap: case nir_intrinsic_image_atomic_fadd: case nir_intrinsic_bindless_image_atomic_add: case nir_intrinsic_bindless_image_atomic_imin: case nir_intrinsic_bindless_image_atomic_umin: case nir_intrinsic_bindless_image_atomic_imax: case nir_intrinsic_bindless_image_atomic_umax: case nir_intrinsic_bindless_image_atomic_and: case nir_intrinsic_bindless_image_atomic_or: case nir_intrinsic_bindless_image_atomic_xor: case nir_intrinsic_bindless_image_atomic_exchange: case nir_intrinsic_bindless_image_atomic_comp_swap: case nir_intrinsic_bindless_image_atomic_fadd: case nir_intrinsic_shared_atomic_add: case nir_intrinsic_shared_atomic_imin: case nir_intrinsic_shared_atomic_umin: case nir_intrinsic_shared_atomic_imax: case nir_intrinsic_shared_atomic_umax: case nir_intrinsic_shared_atomic_and: case nir_intrinsic_shared_atomic_or: case nir_intrinsic_shared_atomic_xor: case nir_intrinsic_shared_atomic_exchange: case nir_intrinsic_shared_atomic_comp_swap: case nir_intrinsic_shared_atomic_fadd: case nir_intrinsic_shared_atomic_fmin: case nir_intrinsic_shared_atomic_fmax: case nir_intrinsic_shared_atomic_fcomp_swap: case nir_intrinsic_global_atomic_add: case nir_intrinsic_global_atomic_imin: case nir_intrinsic_global_atomic_umin: case nir_intrinsic_global_atomic_imax: case nir_intrinsic_global_atomic_umax: case nir_intrinsic_global_atomic_and: case nir_intrinsic_global_atomic_or: case nir_intrinsic_global_atomic_xor: case nir_intrinsic_global_atomic_exchange: case nir_intrinsic_global_atomic_comp_swap: case nir_intrinsic_global_atomic_fadd: case nir_intrinsic_global_atomic_fmin: case nir_intrinsic_global_atomic_fmax: case nir_intrinsic_global_atomic_fcomp_swap: case nir_intrinsic_atomic_counter_add: case nir_intrinsic_atomic_counter_min: case nir_intrinsic_atomic_counter_max: case nir_intrinsic_atomic_counter_and: case nir_intrinsic_atomic_counter_or: case nir_intrinsic_atomic_counter_xor: case nir_intrinsic_atomic_counter_inc: case nir_intrinsic_atomic_counter_pre_dec: case nir_intrinsic_atomic_counter_post_dec: case nir_intrinsic_atomic_counter_exchange: case nir_intrinsic_atomic_counter_comp_swap: case nir_intrinsic_atomic_counter_add_deref: case nir_intrinsic_atomic_counter_min_deref: case nir_intrinsic_atomic_counter_max_deref: case nir_intrinsic_atomic_counter_and_deref: case nir_intrinsic_atomic_counter_or_deref: case nir_intrinsic_atomic_counter_xor_deref: case nir_intrinsic_atomic_counter_inc_deref: case nir_intrinsic_atomic_counter_pre_dec_deref: case nir_intrinsic_atomic_counter_post_dec_deref: case nir_intrinsic_atomic_counter_exchange_deref: case nir_intrinsic_atomic_counter_comp_swap_deref: case nir_intrinsic_exclusive_scan: case nir_intrinsic_ballot_bit_count_exclusive: case nir_intrinsic_ballot_bit_count_inclusive: case nir_intrinsic_write_invocation_amd: case nir_intrinsic_mbcnt_amd: is_divergent = true; break; default: #ifdef NDEBUG is_divergent = true; break; #else nir_print_instr(&instr->instr, stderr); unreachable("\nNIR divergence analysis: Unhandled intrinsic."); #endif } divergent[instr->dest.ssa.index] = is_divergent; return is_divergent; } static bool visit_tex(bool *divergent, nir_tex_instr *instr) { if (divergent[instr->dest.ssa.index]) return false; bool is_divergent = false; for (unsigned i = 0; i < instr->num_srcs; i++) { switch (instr->src[i].src_type) { case nir_tex_src_sampler_deref: case nir_tex_src_sampler_handle: case nir_tex_src_sampler_offset: is_divergent |= divergent[instr->src[i].src.ssa->index] && instr->sampler_non_uniform; break; case nir_tex_src_texture_deref: case nir_tex_src_texture_handle: case nir_tex_src_texture_offset: is_divergent |= divergent[instr->src[i].src.ssa->index] && instr->texture_non_uniform; break; default: is_divergent |= divergent[instr->src[i].src.ssa->index]; break; } } divergent[instr->dest.ssa.index] = is_divergent; return is_divergent; } static bool visit_phi(bool *divergent, nir_phi_instr *instr) { /* There are 3 types of phi instructions: * (1) gamma: represent the joining point of different paths * created by an “if-then-else” branch. * The resulting value is divergent if the branch condition * or any of the source values is divergent. * * (2) mu: which only exist at loop headers, * merge initial and loop-carried values. * The resulting value is divergent if any source value * is divergent or a divergent loop continue condition * is associated with a different ssa-def. * * (3) eta: represent values that leave a loop. * The resulting value is divergent if the source value is divergent * or any loop exit condition is divergent for a value which is * not loop-invariant. * (note: there should be no phi for loop-invariant variables.) */ if (divergent[instr->dest.ssa.index]) return false; nir_foreach_phi_src(src, instr) { /* if any source value is divergent, the resulting value is divergent */ if (divergent[src->src.ssa->index]) { divergent[instr->dest.ssa.index] = true; return true; } } nir_cf_node *prev = nir_cf_node_prev(&instr->instr.block->cf_node); if (!prev) { /* mu: if no predecessor node exists, the phi must be at a loop header */ nir_loop *loop = nir_cf_node_as_loop(instr->instr.block->cf_node.parent); prev = nir_cf_node_prev(&loop->cf_node); nir_ssa_def* same = NULL; bool all_same = true; /* first, check if all loop-carried values are from the same ssa-def */ nir_foreach_phi_src(src, instr) { if (src->pred == nir_cf_node_as_block(prev)) continue; if (src->src.ssa->parent_instr->type == nir_instr_type_ssa_undef) continue; if (!same) same = src->src.ssa; else if (same != src->src.ssa) all_same = false; } /* if all loop-carried values are the same, the resulting value is uniform */ if (all_same) return false; /* check if the loop-carried values come from different ssa-defs * and the corresponding condition is divergent. */ nir_foreach_phi_src(src, instr) { /* skip the loop preheader */ if (src->pred == nir_cf_node_as_block(prev)) continue; /* skip the unconditional back-edge */ if (src->pred == nir_loop_last_block(loop)) continue; /* if the value is undef, we don't need to check the condition */ if (src->src.ssa->parent_instr->type == nir_instr_type_ssa_undef) continue; nir_cf_node *current = src->pred->cf_node.parent; /* check recursively the conditions if any is divergent */ while (current->type != nir_cf_node_loop) { assert (current->type == nir_cf_node_if); nir_if *if_node = nir_cf_node_as_if(current); if (divergent[if_node->condition.ssa->index]) { divergent[instr->dest.ssa.index] = true; return true; } current = current->parent; } assert(current == &loop->cf_node); } } else if (prev->type == nir_cf_node_if) { /* if only one of the incoming values is defined, the resulting value is uniform */ unsigned defined_srcs = 0; nir_foreach_phi_src(src, instr) { if (src->src.ssa->parent_instr->type != nir_instr_type_ssa_undef) defined_srcs++; } if (defined_srcs <= 1) return false; /* gamma: check if the condition is divergent */ nir_if *if_node = nir_cf_node_as_if(prev); if (divergent[if_node->condition.ssa->index]) { divergent[instr->dest.ssa.index] = true; return true; } } else { /* eta: the predecessor must be a loop */ assert(prev->type == nir_cf_node_loop); /* Check if any loop exit condition is divergent: * That is any break happens under divergent condition or * a break is preceeded by a divergent continue */ nir_foreach_phi_src(src, instr) { nir_cf_node *current = src->pred->cf_node.parent; /* check recursively the conditions if any is divergent */ while (current->type != nir_cf_node_loop) { assert(current->type == nir_cf_node_if); nir_if *if_node = nir_cf_node_as_if(current); if (divergent[if_node->condition.ssa->index]) { divergent[instr->dest.ssa.index] = true; return true; } current = current->parent; } assert(current == prev); /* check if any divergent continue happened before the break */ nir_foreach_block_in_cf_node(block, prev) { if (block == src->pred) break; if (!nir_block_ends_in_jump(block)) continue; nir_jump_instr *jump = nir_instr_as_jump(nir_block_last_instr(block)); if (jump->type != nir_jump_continue) continue; current = block->cf_node.parent; bool is_divergent = false; while (current != prev) { /* the continue belongs to an inner loop */ if (current->type == nir_cf_node_loop) { is_divergent = false; break; } assert(current->type == nir_cf_node_if); nir_if *if_node = nir_cf_node_as_if(current); is_divergent |= divergent[if_node->condition.ssa->index]; current = current->parent; } if (is_divergent) { divergent[instr->dest.ssa.index] = true; return true; } } } } return false; } static bool visit_load_const(bool *divergent, nir_load_const_instr *instr) { return false; } static bool visit_ssa_undef(bool *divergent, nir_ssa_undef_instr *instr) { return false; } static bool nir_variable_mode_is_uniform(nir_variable_mode mode) { switch (mode) { case nir_var_uniform: case nir_var_mem_ubo: case nir_var_mem_ssbo: case nir_var_mem_shared: case nir_var_mem_global: return true; default: return false; } } static bool nir_variable_is_uniform(nir_variable *var, nir_divergence_options options, gl_shader_stage stage) { if (nir_variable_mode_is_uniform(var->data.mode)) return true; if (stage == MESA_SHADER_FRAGMENT && (options & nir_divergence_single_prim_per_subgroup) && var->data.mode == nir_var_shader_in && var->data.interpolation == INTERP_MODE_FLAT) return true; if (stage == MESA_SHADER_TESS_CTRL && (options & nir_divergence_single_patch_per_tcs_subgroup) && var->data.mode == nir_var_shader_out && var->data.patch) return true; if (stage == MESA_SHADER_TESS_EVAL && (options & nir_divergence_single_patch_per_tes_subgroup) && var->data.mode == nir_var_shader_in && var->data.patch) return true; return false; } static bool visit_deref(bool *divergent, nir_deref_instr *deref, nir_divergence_options options, gl_shader_stage stage) { if (divergent[deref->dest.ssa.index]) return false; bool is_divergent = false; switch (deref->deref_type) { case nir_deref_type_var: is_divergent = !nir_variable_is_uniform(deref->var, options, stage); break; case nir_deref_type_array: case nir_deref_type_ptr_as_array: is_divergent = divergent[deref->arr.index.ssa->index]; /* fallthrough */ case nir_deref_type_struct: case nir_deref_type_array_wildcard: is_divergent |= divergent[deref->parent.ssa->index]; break; case nir_deref_type_cast: is_divergent = !nir_variable_mode_is_uniform(deref->var->data.mode) || divergent[deref->parent.ssa->index]; break; } divergent[deref->dest.ssa.index] = is_divergent; return is_divergent; } static bool visit_block(bool *divergent, nir_block *block, nir_divergence_options options, gl_shader_stage stage) { bool has_changed = false; nir_foreach_instr(instr, block) { switch (instr->type) { case nir_instr_type_alu: has_changed |= visit_alu(divergent, nir_instr_as_alu(instr)); break; case nir_instr_type_intrinsic: has_changed |= visit_intrinsic(divergent, nir_instr_as_intrinsic(instr), options, stage); break; case nir_instr_type_tex: has_changed |= visit_tex(divergent, nir_instr_as_tex(instr)); break; case nir_instr_type_phi: has_changed |= visit_phi(divergent, nir_instr_as_phi(instr)); break; case nir_instr_type_load_const: has_changed |= visit_load_const(divergent, nir_instr_as_load_const(instr)); break; case nir_instr_type_ssa_undef: has_changed |= visit_ssa_undef(divergent, nir_instr_as_ssa_undef(instr)); break; case nir_instr_type_deref: has_changed |= visit_deref(divergent, nir_instr_as_deref(instr), options, stage); break; case nir_instr_type_jump: break; case nir_instr_type_call: case nir_instr_type_parallel_copy: unreachable("NIR divergence analysis: Unsupported instruction type."); } } return has_changed; } static bool visit_if(bool *divergent, nir_if *if_stmt, nir_divergence_options options, gl_shader_stage stage) { return visit_cf_list(divergent, &if_stmt->then_list, options, stage) | visit_cf_list(divergent, &if_stmt->else_list, options, stage); } static bool visit_loop(bool *divergent, nir_loop *loop, nir_divergence_options options, gl_shader_stage stage) { bool has_changed = false; bool repeat = true; /* TODO: restructure this and the phi handling more efficiently */ while (repeat) { repeat = visit_cf_list(divergent, &loop->body, options, stage); has_changed |= repeat; } return has_changed; } static bool visit_cf_list(bool *divergent, struct exec_list *list, nir_divergence_options options, gl_shader_stage stage) { bool has_changed = false; foreach_list_typed(nir_cf_node, node, node, list) { switch (node->type) { case nir_cf_node_block: has_changed |= visit_block(divergent, nir_cf_node_as_block(node), options, stage); break; case nir_cf_node_if: has_changed |= visit_if(divergent, nir_cf_node_as_if(node), options, stage); break; case nir_cf_node_loop: has_changed |= visit_loop(divergent, nir_cf_node_as_loop(node), options, stage); break; case nir_cf_node_function: unreachable("NIR divergence analysis: Unsupported cf_node type."); } } return has_changed; } bool* nir_divergence_analysis(nir_shader *shader, nir_divergence_options options) { nir_function_impl *impl = nir_shader_get_entrypoint(shader); bool *t = rzalloc_array(shader, bool, impl->ssa_alloc); visit_cf_list(t, &impl->body, options, shader->info.stage); return t; }