/* * Copyright © 2016 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 "nir_deref.h" static void emit_load_store_deref(nir_builder *b, nir_intrinsic_instr *orig_instr, nir_deref_instr *parent, nir_deref_instr **deref_arr, nir_ssa_def **dest, nir_ssa_def *src); static void emit_indirect_load_store_deref(nir_builder *b, nir_intrinsic_instr *orig_instr, nir_deref_instr *parent, nir_deref_instr **deref_arr, int start, int end, nir_ssa_def **dest, nir_ssa_def *src) { assert(start < end); if (start == end - 1) { nir_ssa_def *index = nir_imm_int(b, start); emit_load_store_deref(b, orig_instr, nir_build_deref_array(b, parent, index), deref_arr + 1, dest, src); } else { int mid = start + (end - start) / 2; nir_ssa_def *then_dest, *else_dest; nir_deref_instr *deref = *deref_arr; assert(deref->deref_type == nir_deref_type_array); nir_push_if(b, nir_ilt(b, deref->arr.index.ssa, nir_imm_int(b, mid))); emit_indirect_load_store_deref(b, orig_instr, parent, deref_arr, start, mid, &then_dest, src); nir_push_else(b, NULL); emit_indirect_load_store_deref(b, orig_instr, parent, deref_arr, mid, end, &else_dest, src); nir_pop_if(b, NULL); if (src == NULL) *dest = nir_if_phi(b, then_dest, else_dest); } } static void emit_load_store_deref(nir_builder *b, nir_intrinsic_instr *orig_instr, nir_deref_instr *parent, nir_deref_instr **deref_arr, nir_ssa_def **dest, nir_ssa_def *src) { for (; *deref_arr; deref_arr++) { nir_deref_instr *deref = *deref_arr; if (deref->deref_type == nir_deref_type_array && !nir_src_is_const(deref->arr.index)) { int length = glsl_get_length(parent->type); emit_indirect_load_store_deref(b, orig_instr, parent, deref_arr, 0, length, dest, src); return; } parent = nir_build_deref_follower(b, parent, deref); } /* We reached the end of the deref chain. Emit the instruction */ assert(*deref_arr == NULL); if (src == NULL) { /* This is a load instruction */ nir_intrinsic_instr *load = nir_intrinsic_instr_create(b->shader, orig_instr->intrinsic); load->num_components = orig_instr->num_components; load->src[0] = nir_src_for_ssa(&parent->dest.ssa); /* Copy over any other sources. This is needed for interp_deref_at */ for (unsigned i = 1; i < nir_intrinsic_infos[orig_instr->intrinsic].num_srcs; i++) nir_src_copy(&load->src[i], &orig_instr->src[i], load); nir_ssa_dest_init(&load->instr, &load->dest, orig_instr->dest.ssa.num_components, orig_instr->dest.ssa.bit_size, NULL); nir_builder_instr_insert(b, &load->instr); *dest = &load->dest.ssa; } else { assert(orig_instr->intrinsic == nir_intrinsic_store_deref); nir_store_deref(b, parent, src, nir_intrinsic_write_mask(orig_instr)); } } static bool lower_indirect_derefs_block(nir_block *block, nir_builder *b, nir_variable_mode modes) { bool progress = false; nir_foreach_instr_safe(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 && intrin->intrinsic != nir_intrinsic_interp_deref_at_centroid && intrin->intrinsic != nir_intrinsic_interp_deref_at_sample && intrin->intrinsic != nir_intrinsic_interp_deref_at_offset && intrin->intrinsic != nir_intrinsic_store_deref) continue; nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]); /* Walk the deref chain back to the base and look for indirects */ bool has_indirect = false; nir_deref_instr *base = deref; while (base && base->deref_type != nir_deref_type_var) { if (base->deref_type == nir_deref_type_array && !nir_src_is_const(base->arr.index)) has_indirect = true; base = nir_deref_instr_parent(base); } if (!has_indirect || !base) continue; /* Only lower variables whose mode is in the mask, or compact * array variables. (We can't handle indirects on tightly packed * scalar arrays, so we need to lower them regardless.) */ if (!(modes & base->var->data.mode) && !base->var->data.compact) continue; b->cursor = nir_instr_remove(&intrin->instr); nir_deref_path path; nir_deref_path_init(&path, deref, NULL); assert(path.path[0] == base); if (intrin->intrinsic == nir_intrinsic_store_deref) { assert(intrin->src[1].is_ssa); emit_load_store_deref(b, intrin, base, &path.path[1], NULL, intrin->src[1].ssa); } else { nir_ssa_def *result; emit_load_store_deref(b, intrin, base, &path.path[1], &result, NULL); nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(result)); } nir_deref_path_finish(&path); progress = true; } return progress; } static bool lower_indirects_impl(nir_function_impl *impl, nir_variable_mode modes) { nir_builder builder; nir_builder_init(&builder, impl); bool progress = false; nir_foreach_block_safe(block, impl) { progress |= lower_indirect_derefs_block(block, &builder, modes); } if (progress) nir_metadata_preserve(impl, nir_metadata_none); return progress; } /** Lowers indirect variable loads/stores to direct loads/stores. * * The pass works by replacing any indirect load or store with an if-ladder * that does a binary search on the array index. */ bool nir_lower_indirect_derefs(nir_shader *shader, nir_variable_mode modes) { bool progress = false; nir_foreach_function(function, shader) { if (function->impl) progress = lower_indirects_impl(function->impl, modes) || progress; } return progress; }