| /* |
| * 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, or compact |
| * array variables. (We can't handle indirects on tightly packed |
| * scalar arrays, so we need to lower them regardless.) |
| */ |
| if (!(modes & intrin->variables[0]->var->data.mode) && |
| !intrin->variables[0]->var->data.compact) |
| 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; |
| } |
