/* * Copyright © 2010 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. */ /** * \file lower_vector.cpp * IR lowering pass to remove some types of ir_quadop_vector * * \author Ian Romanick <ian.d.romanick@intel.com> */ #include "ir.h" #include "ir_rvalue_visitor.h" class lower_vector_visitor : public ir_rvalue_visitor { public: lower_vector_visitor() : progress(false) { /* empty */ } void handle_rvalue(ir_rvalue **rvalue); /** * Should SWZ-like expressions be lowered? */ bool dont_lower_swz; bool progress; }; /** * Determine if an IR expression tree looks like an extended swizzle * * Extended swizzles consist of access of a single vector source (with possible * per component negation) and the constants -1, 0, or 1. */ bool is_extended_swizzle(ir_expression *ir) { /* Track any variables that are accessed by this expression. */ ir_variable *var = NULL; assert(ir->operation == ir_quadop_vector); for (unsigned i = 0; i < ir->type->vector_elements; i++) { ir_rvalue *op = ir->operands[i]; while (op != NULL) { switch (op->ir_type) { case ir_type_constant: { const ir_constant *const c = op->as_constant(); if (!c->is_one() && !c->is_zero() && !c->is_negative_one()) return false; op = NULL; break; } case ir_type_dereference_variable: { ir_dereference_variable *const d = (ir_dereference_variable *) op; if ((var != NULL) && (var != d->var)) return false; var = d->var; op = NULL; break; } case ir_type_expression: { ir_expression *const ex = (ir_expression *) op; if (ex->operation != ir_unop_neg) return false; op = ex->operands[0]; break; } case ir_type_swizzle: op = ((ir_swizzle *) op)->val; break; default: return false; } } } return true; } void lower_vector_visitor::handle_rvalue(ir_rvalue **rvalue) { if (!*rvalue) return; ir_expression *expr = (*rvalue)->as_expression(); if ((expr == NULL) || (expr->operation != ir_quadop_vector)) return; if (this->dont_lower_swz && is_extended_swizzle(expr)) return; /* FINISHME: Is this the right thing to use for the ralloc context? */ void *const mem_ctx = expr; assert(expr->type->vector_elements == expr->get_num_operands()); /* Generate a temporary with the same type as the ir_quadop_operation. */ ir_variable *const temp = new(mem_ctx) ir_variable(expr->type, "vecop_tmp", ir_var_temporary); this->base_ir->insert_before(temp); /* Counter of the number of components collected so far. */ unsigned assigned; /* Write-mask in the destination that receives counted by 'assigned'. */ unsigned write_mask; /* Generate upto four assignments to that variable. Try to group component * assignments together: * * - All constant components can be assigned at once. * - All assigments of components from a single variable with the same * unary operator can be assigned at once. */ ir_constant_data d = { { 0 } }; assigned = 0; write_mask = 0; for (unsigned i = 0; i < expr->type->vector_elements; i++) { const ir_constant *const c = expr->operands[i]->as_constant(); if (c == NULL) continue; switch (expr->type->base_type) { case GLSL_TYPE_UINT: d.u[assigned] = c->value.u[0]; break; case GLSL_TYPE_INT: d.i[assigned] = c->value.i[0]; break; case GLSL_TYPE_FLOAT: d.f[assigned] = c->value.f[0]; break; case GLSL_TYPE_BOOL: d.b[assigned] = c->value.b[0]; break; default: assert(!"Should not get here."); break; } write_mask |= (1U << i); assigned++; } assert((write_mask == 0) == (assigned == 0)); /* If there were constant values, generate an assignment. */ if (assigned > 0) { ir_constant *const c = new(mem_ctx) ir_constant(glsl_type::get_instance(expr->type->base_type, assigned, 0), &d); ir_dereference *const lhs = new(mem_ctx) ir_dereference_variable(temp); ir_assignment *const assign = new(mem_ctx) ir_assignment(lhs, c, NULL, write_mask); this->base_ir->insert_before(assign); } /* FINISHME: This should try to coalesce assignments. */ for (unsigned i = 0; i < expr->type->vector_elements; i++) { if (expr->operands[i]->ir_type == ir_type_constant) continue; ir_dereference *const lhs = new(mem_ctx) ir_dereference_variable(temp); ir_assignment *const assign = new(mem_ctx) ir_assignment(lhs, expr->operands[i], NULL, (1U << i)); this->base_ir->insert_before(assign); assigned++; } assert(assigned == expr->type->vector_elements); *rvalue = new(mem_ctx) ir_dereference_variable(temp); this->progress = true; } bool lower_quadop_vector(exec_list *instructions, bool dont_lower_swz) { lower_vector_visitor v; v.dont_lower_swz = dont_lower_swz; visit_list_elements(&v, instructions); return v.progress; }