ir_constant_folding.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file ir_constant_folding.cpp
  26  * Replace constant-valued expressions with references to constant values.
  27  */
  28
  29 #define NULL 0
  30 #include "ir.h"
  31 #include "ir_visitor.h"
  32 #include "ir_constant_folding.h"
  33 #include "glsl_types.h"
  34
  35 /**
  36  * Visitor class for replacing expressions with ir_constant values.
  37  */
  38
  39 void
  40 ir_constant_folding_visitor::visit(ir_variable *ir)
  41 {
  42    (void) ir;
  43 }
  44
  45
  46 void
  47 ir_constant_folding_visitor::visit(ir_function_signature *ir)
  48 {
  49    visit_exec_list(&ir->body, this);
  50 }
  51
  52
  53 void
  54 ir_constant_folding_visitor::visit(ir_function *ir)
  55 {
  56    (void) ir;
  57 }
  58
  59 void
  60 ir_constant_folding_visitor::visit(ir_expression *ir)
  61 {
  62    ir_constant *op[2];
  63    unsigned int operand;
  64
  65    for (operand = 0; operand < ir->get_num_operands(); operand++) {
  66       op[operand] = ir->operands[operand]->constant_expression_value();
  67       if (op[operand]) {
  68          ir->operands[operand] = op[operand];
  69       } else {
  70          ir->operands[operand]->accept(this);
  71       }
  72    }
  73 }
  74
  75
  76 void
  77 ir_constant_folding_visitor::visit(ir_swizzle *ir)
  78 {
  79    ir->val->accept(this);
  80 }
  81
  82
  83 void
  84 ir_constant_folding_visitor::visit(ir_dereference *ir)
  85 {
  86    if (ir->mode == ir_dereference::ir_reference_array) {
  87       ir_constant *const_val = ir->selector.array_index->constant_expression_value();
  88       if (const_val)
  89          ir->selector.array_index = const_val;
  90       else
  91          ir->selector.array_index->accept(this);
  92    }
  93    ir->var->accept(this);
  94 }
  95
  96
  97 void
  98 ir_constant_folding_visitor::visit(ir_assignment *ir)
  99 {
 100    ir_constant *const_val = ir->rhs->constant_expression_value();
 101    if (const_val)
 102       ir->rhs = const_val;
 103    else
 104       ir->rhs->accept(this);
 105 }
 106
 107
 108 void
 109 ir_constant_folding_visitor::visit(ir_constant *ir)
 110 {
 111    (void) ir;
 112 }
 113
 114
 115 void
 116 ir_constant_folding_visitor::visit(ir_call *ir)
 117 {
 118    (void) ir;
 119 }
 120
 121
 122 void
 123 ir_constant_folding_visitor::visit(ir_return *ir)
 124 {
 125    (void) ir;
 126 }
 127
 128
 129 void
 130 ir_constant_folding_visitor::visit(ir_if *ir)
 131 {
 132    ir_constant *const_val = ir->condition->constant_expression_value();
 133    if (const_val)
 134       ir->condition = const_val;
 135    else
 136       ir->condition->accept(this);
 137
 138    visit_exec_list(&ir->then_instructions, this);
 139    visit_exec_list(&ir->else_instructions, this);
 140 }
 141
 142
 143 void
 144 ir_constant_folding_visitor::visit(ir_loop *ir)
 145 {
 146    (void) ir;
 147 }
 148
 149
 150 void
 151 ir_constant_folding_visitor::visit(ir_loop_jump *ir)
 152 {
 153    (void) ir;
 154 }