1f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org/* 2f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * Copyright © 2010 Intel Corporation 3f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * 4f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * Permission is hereby granted, free of charge, to any person obtaining a 5f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * copy of this software and associated documentation files (the "Software"), 6f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * to deal in the Software without restriction, including without limitation 7f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * and/or sell copies of the Software, and to permit persons to whom the 9f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * Software is furnished to do so, subject to the following conditions: 10f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * 11f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * The above copyright notice and this permission notice (including the next 12f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * paragraph) shall be included in all copies or substantial portions of the 13f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * Software. 14f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * 15f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 21f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * DEALINGS IN THE SOFTWARE. 22f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org */ 23f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 24f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org/** 25f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * \file opt_constant_folding.cpp 26f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * Replace constant-valued expressions with references to constant values. 27f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org */ 28f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 29f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org#include "ir.h" 30f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org#include "ir_visitor.h" 31f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org#include "ir_rvalue_visitor.h" 32f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org#include "ir_optimization.h" 33f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org#include "glsl_types.h" 34f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 35f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgnamespace { 36f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 37f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org/** 38f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * Visitor class for replacing expressions with ir_constant values. 39f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org */ 40f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 41f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgclass ir_constant_folding_visitor : public ir_rvalue_visitor { 42f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgpublic: 43f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_constant_folding_visitor() 44f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org { 45f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org this->progress = false; 46f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 47f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 48f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org virtual ~ir_constant_folding_visitor() 49f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org { 50f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org /* empty */ 51f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 52f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 53f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org virtual ir_visitor_status visit_enter(ir_assignment *ir); 54f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org virtual ir_visitor_status visit_enter(ir_call *ir); 55f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 56f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org virtual void handle_rvalue(ir_rvalue **rvalue); 57f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 58f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org bool progress; 59f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org}; 60f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 61f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org} /* unnamed namespace */ 62f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 63f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgvoid 64f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgir_constant_folding_visitor::handle_rvalue(ir_rvalue **rvalue) 65f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org{ 66f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (*rvalue == NULL || (*rvalue)->ir_type == ir_type_constant) 67f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org return; 68f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 69f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org /* Note that we do rvalue visitoring on leaving. So if an 70f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * expression has a non-constant operand, no need to go looking 71f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * down it to find if it's constant. This cuts the time of this 72f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * pass down drastically. 73f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org */ 74f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_expression *expr = (*rvalue)->as_expression(); 75f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (expr) { 76f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org for (unsigned int i = 0; i < expr->get_num_operands(); i++) { 77f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (!expr->operands[i]->as_constant()) 78f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org return; 79f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 80f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 81f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 82f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_constant *constant = (*rvalue)->constant_expression_value(); 83f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (constant) { 84f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org *rvalue = constant; 85f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org this->progress = true; 86f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } else { 87f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org (*rvalue)->accept(this); 88f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 89f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org} 90f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 91f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgir_visitor_status 92f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgir_constant_folding_visitor::visit_enter(ir_assignment *ir) 93f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org{ 94f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir->rhs->accept(this); 95f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org handle_rvalue(&ir->rhs); 96f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 97f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (ir->condition) { 98f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir->condition->accept(this); 99f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org handle_rvalue(&ir->condition); 100f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 101f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_constant *const_val = ir->condition->as_constant(); 102f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org /* If the condition is constant, either remove the condition or 103f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * remove the never-executed assignment. 104f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org */ 105f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (const_val) { 106f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (const_val->value.b[0]) 107f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir->condition = NULL; 108f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org else 109f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir->remove(); 110f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org this->progress = true; 111f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 112f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 113f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 114f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org /* Don't descend into the LHS because we want it to stay as a 115f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * variable dereference. FINISHME: We probably should to get array 116f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org * indices though. 117f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org */ 118f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org return visit_continue_with_parent; 119f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org} 120f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 121f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgir_visitor_status 122f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgir_constant_folding_visitor::visit_enter(ir_call *ir) 123f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org{ 124f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org /* Attempt to constant fold parameters */ 125f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org exec_list_iterator sig_iter = ir->callee->parameters.iterator(); 126f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org foreach_iter(exec_list_iterator, iter, *ir) { 127f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_rvalue *param_rval = (ir_rvalue *)iter.get(); 128f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_variable *sig_param = (ir_variable *)sig_iter.get(); 129f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 130f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (sig_param->mode == ir_var_in || sig_param->mode == ir_var_const_in) { 131f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_rvalue *new_param = param_rval; 132f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 133f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org handle_rvalue(&new_param); 134f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (new_param != param_rval) { 135f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org param_rval->replace_with(new_param); 136f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 137f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 138f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org sig_iter.next(); 139f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 140f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 141f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org /* Next, see if the call can be replaced with an assignment of a constant */ 142f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_constant *const_val = ir->constant_expression_value(); 143f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 144f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org if (const_val != NULL) { 145f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_assignment *assignment = 146f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org new(ralloc_parent(ir)) ir_assignment(ir->return_deref, const_val); 147f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir->replace_with(assignment); 148f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org } 149f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 150f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org return visit_continue_with_parent; 151f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org} 152f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 153f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgbool 154f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.orgdo_constant_folding(exec_list *instructions) 155f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org{ 156f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org ir_constant_folding_visitor constant_folding; 157f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 158f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org visit_list_elements(&constant_folding, instructions); 159f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org 160f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org return constant_folding.progress; 161f2ba7591b1407a7ee9209f842c50696914dc2dedkbr@chromium.org} 162