/* * 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" static void emit_load_store(nir_builder *b, nir_intrinsic_instr *orig_instr, nir_deref_var *deref, nir_deref *tail, nir_ssa_def **dest, nir_ssa_def *src); static void emit_indirect_load_store(nir_builder *b, nir_intrinsic_instr *orig_instr, nir_deref_var *deref, nir_deref *arr_parent, int start, int end, nir_ssa_def **dest, nir_ssa_def *src) { nir_deref_array *arr = nir_deref_as_array(arr_parent->child); assert(arr->deref_array_type == nir_deref_array_type_indirect); assert(arr->indirect.is_ssa); assert(start < end); if (start == end - 1) { /* Base case. Just emit the load/store op */ nir_deref_array direct = *arr; direct.deref_array_type = nir_deref_array_type_direct; direct.base_offset += start; direct.indirect = NIR_SRC_INIT; arr_parent->child = &direct.deref; emit_load_store(b, orig_instr, deref, &direct.deref, dest, src); arr_parent->child = &arr->deref; } else { int mid = start + (end - start) / 2; nir_ssa_def *then_dest, *else_dest; nir_if *if_stmt = nir_if_create(b->shader); if_stmt->condition = nir_src_for_ssa(nir_ilt(b, arr->indirect.ssa, nir_imm_int(b, mid))); nir_cf_node_insert(b->cursor, &if_stmt->cf_node); b->cursor = nir_after_cf_list(&if_stmt->then_list); emit_indirect_load_store(b, orig_instr, deref, arr_parent, start, mid, &then_dest, src); b->cursor = nir_after_cf_list(&if_stmt->else_list); emit_indirect_load_store(b, orig_instr, deref, arr_parent, mid, end, &else_dest, src); b->cursor = nir_after_cf_node(&if_stmt->cf_node); if (src == NULL) { /* We're a load. We need to insert a phi node */ nir_phi_instr *phi = nir_phi_instr_create(b->shader); unsigned bit_size = then_dest->bit_size; nir_ssa_dest_init(&phi->instr, &phi->dest, then_dest->num_components, bit_size, NULL); nir_phi_src *src0 = ralloc(phi, nir_phi_src); src0->pred = nir_if_last_then_block(if_stmt); src0->src = nir_src_for_ssa(then_dest); exec_list_push_tail(&phi->srcs, &src0->node); nir_phi_src *src1 = ralloc(phi, nir_phi_src); src1->pred = nir_if_last_else_block(if_stmt); src1->src = nir_src_for_ssa(else_dest); exec_list_push_tail(&phi->srcs, &src1->node); nir_builder_instr_insert(b, &phi->instr); *dest = &phi->dest.ssa; } } } static void emit_load_store(nir_builder *b, nir_intrinsic_instr *orig_instr, nir_deref_var *deref, nir_deref *tail, nir_ssa_def **dest, nir_ssa_def *src) { for (; tail->child; tail = tail->child) { if (tail->child->deref_type != nir_deref_type_array) continue; nir_deref_array *arr = nir_deref_as_array(tail->child); if (arr->deref_array_type != nir_deref_array_type_indirect) continue; int length = glsl_get_length(tail->type); emit_indirect_load_store(b, orig_instr, deref, tail, -arr->base_offset, length - arr->base_offset, dest, src); return; } assert(tail && tail->child == NULL); /* We reached the end of the deref chain. Emit the instruction */ if (src == NULL) { /* This is a load instruction */ nir_intrinsic_instr *load = nir_intrinsic_instr_create(b->shader, nir_intrinsic_load_var); load->num_components = orig_instr->num_components; load->variables[0] = nir_deref_as_var(nir_copy_deref(load, &deref->deref)); unsigned bit_size = orig_instr->dest.ssa.bit_size; nir_ssa_dest_init(&load->instr, &load->dest, load->num_components, bit_size, NULL); nir_builder_instr_insert(b, &load->instr); *dest = &load->dest.ssa; } else { /* This is a store instruction */ nir_intrinsic_instr *store = nir_intrinsic_instr_create(b->shader, nir_intrinsic_store_var); store->num_components = orig_instr->num_components; nir_intrinsic_set_write_mask(store, nir_intrinsic_write_mask(orig_instr)); store->variables[0] = nir_deref_as_var(nir_copy_deref(store, &deref->deref)); store->src[0] = nir_src_for_ssa(src); nir_builder_instr_insert(b, &store->instr); } } static bool deref_has_indirect(nir_deref_var *deref) { for (nir_deref *tail = deref->deref.child; tail; tail = tail->child) { if (tail->deref_type != nir_deref_type_array) continue; nir_deref_array *arr = nir_deref_as_array(tail); if (arr->deref_array_type == nir_deref_array_type_indirect) return true; } return false; } static bool lower_indirect_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_var && intrin->intrinsic != nir_intrinsic_store_var) continue; if (!deref_has_indirect(intrin->variables[0])) continue; /* Only lower variables whose mode is in the mask */ if (!(modes & intrin->variables[0]->var->data.mode)) continue; b->cursor = nir_before_instr(&intrin->instr); if (intrin->intrinsic == nir_intrinsic_load_var) { nir_ssa_def *result; emit_load_store(b, intrin, intrin->variables[0], &intrin->variables[0]->deref, &result, NULL); nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(result)); } else { assert(intrin->src[0].is_ssa); emit_load_store(b, intrin, intrin->variables[0], &intrin->variables[0]->deref, NULL, intrin->src[0].ssa); } nir_instr_remove(&intrin->instr); 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_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; }