/* * Copyright © 2013 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 "ir.h" #include "ir_builder.h" #include "ir_rvalue_visitor.h" #include "ir_optimization.h" #include "main/mtypes.h" using namespace ir_builder; namespace { class vector_deref_visitor : public ir_rvalue_enter_visitor { public: vector_deref_visitor(void *mem_ctx, gl_shader_stage shader_stage) : progress(false), shader_stage(shader_stage), factory(&factory_instructions, mem_ctx) { } virtual ~vector_deref_visitor() { } virtual void handle_rvalue(ir_rvalue **rv); virtual ir_visitor_status visit_enter(ir_assignment *ir); bool progress; gl_shader_stage shader_stage; exec_list factory_instructions; ir_factory factory; }; } /* anonymous namespace */ ir_visitor_status vector_deref_visitor::visit_enter(ir_assignment *ir) { if (!ir->lhs || ir->lhs->ir_type != ir_type_dereference_array) return ir_rvalue_enter_visitor::visit_enter(ir); ir_dereference_array *const deref = (ir_dereference_array *) ir->lhs; if (!deref->array->type->is_vector()) return ir_rvalue_enter_visitor::visit_enter(ir); /* SSBOs and shared variables are backed by memory and may be accessed by * multiple threads simultaneously. It's not safe to lower a single * component store to a load-vec-store because it may race with writes to * other components. */ ir_variable *var = deref->variable_referenced(); if (var->data.mode == ir_var_shader_storage || var->data.mode == ir_var_shader_shared) return ir_rvalue_enter_visitor::visit_enter(ir); ir_rvalue *const new_lhs = deref->array; void *mem_ctx = ralloc_parent(ir); ir_constant *old_index_constant = deref->array_index->constant_expression_value(mem_ctx); if (!old_index_constant) { if (shader_stage == MESA_SHADER_TESS_CTRL && deref->variable_referenced()->data.mode == ir_var_shader_out) { /* Tessellation control shader outputs act as if they have memory * backing them and if we have writes from multiple threads * targeting the same vec4 (this can happen for patch outputs), the * load-vec-store pattern of ir_triop_vector_insert doesn't work. * Instead, we have to lower to a series of conditional write-masked * assignments. */ ir_variable *const src_temp = factory.make_temp(ir->rhs->type, "scalar_tmp"); /* The newly created variable declaration goes before the assignment * because we're going to set it as the new LHS. */ ir->insert_before(factory.instructions); ir->set_lhs(new(mem_ctx) ir_dereference_variable(src_temp)); ir_variable *const arr_index = factory.make_temp(deref->array_index->type, "index_tmp"); factory.emit(assign(arr_index, deref->array_index)); for (unsigned i = 0; i < new_lhs->type->vector_elements; i++) { ir_constant *const cmp_index = ir_constant::zero(factory.mem_ctx, deref->array_index->type); cmp_index->value.u[0] = i; ir_rvalue *const lhs_clone = new_lhs->clone(factory.mem_ctx, NULL); ir_dereference_variable *const src_temp_deref = new(mem_ctx) ir_dereference_variable(src_temp); if (new_lhs->ir_type != ir_type_swizzle) { assert(lhs_clone->as_dereference()); ir_assignment *cond_assign = new(mem_ctx) ir_assignment(lhs_clone->as_dereference(), src_temp_deref, equal(arr_index, cmp_index), WRITEMASK_X << i); factory.emit(cond_assign); } else { ir_assignment *cond_assign = new(mem_ctx) ir_assignment(swizzle(lhs_clone, i, 1), src_temp_deref, equal(arr_index, cmp_index)); factory.emit(cond_assign); } } ir->insert_after(factory.instructions); } else { ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert, new_lhs->type, new_lhs->clone(mem_ctx, NULL), ir->rhs, deref->array_index); ir->write_mask = (1 << new_lhs->type->vector_elements) - 1; ir->set_lhs(new_lhs); } } else if (new_lhs->ir_type != ir_type_swizzle) { ir->set_lhs(new_lhs); ir->write_mask = 1 << old_index_constant->get_uint_component(0); } else { /* If the "new" LHS is a swizzle, use the set_lhs helper to instead * swizzle the RHS. */ unsigned component[1] = { old_index_constant->get_uint_component(0) }; ir->set_lhs(new(mem_ctx) ir_swizzle(new_lhs, component, 1)); } return ir_rvalue_enter_visitor::visit_enter(ir); } void vector_deref_visitor::handle_rvalue(ir_rvalue **rv) { if (*rv == NULL || (*rv)->ir_type != ir_type_dereference_array) return; ir_dereference_array *const deref = (ir_dereference_array *) *rv; if (!deref->array->type->is_vector()) return; /* Back-ends need to be able to handle derefs on vectors for SSBOs, UBOs, * and shared variables. They have to handle it for writes anyway so we * may as well require it for reads. */ ir_variable *var = deref->variable_referenced(); if (var && (var->data.mode == ir_var_shader_storage || var->data.mode == ir_var_shader_shared || (var->data.mode == ir_var_uniform && var->get_interface_type()))) return; void *mem_ctx = ralloc_parent(deref); *rv = new(mem_ctx) ir_expression(ir_binop_vector_extract, deref->array, deref->array_index); } bool lower_vector_derefs(gl_linked_shader *shader) { vector_deref_visitor v(shader->ir, shader->Stage); visit_list_elements(&v, shader->ir); return v.progress; }