src/glsl/ir_variable_refcount.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_variable_refcount.cpp
  26  *
  27  * Provides a visitor which produces a list of variables referenced,
  28  * how many times they were referenced and assigned, and whether they
  29  * were defined in the scope.
  30  */
  31
  32 #include "ir.h"
  33 #include "ir_visitor.h"
  34 #include "ir_variable_refcount.h"
  35 #include "glsl_types.h"
  36
  37 variable_entry *
  38 ir_variable_refcount_visitor::get_variable_entry(ir_variable *var)
  39 {
  40    assert(var);
  41    foreach_iter(exec_list_iterator, iter, this->variable_list) {
  42       variable_entry *entry = (variable_entry *)iter.get();
  43       if (entry->var == var)
  44          return entry;
  45    }
  46
  47    variable_entry *entry = new(mem_ctx) variable_entry(var);
  48    this->variable_list.push_tail(entry);
  49    return entry;
  50 }
  51
  52
  53 ir_visitor_status
  54 ir_variable_refcount_visitor::visit(ir_variable *ir)
  55 {
  56    variable_entry *entry = this->get_variable_entry(ir);
  57    if (entry)
  58       entry->declaration = true;
  59
  60    return visit_continue;
  61 }
  62
  63
  64 ir_visitor_status
  65 ir_variable_refcount_visitor::visit(ir_dereference_variable *ir)
  66 {
  67    ir_variable *const var = ir->variable_referenced();
  68    variable_entry *entry = this->get_variable_entry(var);
  69
  70    if (entry)
  71       entry->referenced_count++;
  72
  73    return visit_continue;
  74 }
  75
  76
  77 ir_visitor_status
  78 ir_variable_refcount_visitor::visit_enter(ir_function_signature *ir)
  79 {
  80    /* We don't want to descend into the function parameters and
  81     * dead-code eliminate them, so just accept the body here.
  82     */
  83    visit_list_elements(this, &ir->body);
  84    return visit_continue_with_parent;
  85 }
  86
  87
  88 ir_visitor_status
  89 ir_variable_refcount_visitor::visit_leave(ir_assignment *ir)
  90 {
  91    variable_entry *entry;
  92    entry = this->get_variable_entry(ir->lhs->variable_referenced());
  93    if (entry) {
  94       entry->assigned_count++;
  95       if (entry->assign == NULL)
  96          entry->assign = ir;
  97    }
  98
  99    return visit_continue;
 100 }