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
38 // constructor
ir_variable_refcount_entry(ir_variable * var)39 ir_variable_refcount_entry::ir_variable_refcount_entry(ir_variable *var)
40 {
41 this->var = var;
42 assign = NULL;
43 assigned_count = 0;
44 declaration = false;
45 referenced_count = 0;
46 }
47
48
49 ir_variable_refcount_entry *
get_variable_entry(ir_variable * var)50 ir_variable_refcount_visitor::get_variable_entry(ir_variable *var)
51 {
52 assert(var);
53 foreach_iter(exec_list_iterator, iter, this->variable_list) {
54 ir_variable_refcount_entry *entry = (ir_variable_refcount_entry *)iter.get();
55 if (entry->var == var)
56 return entry;
57 }
58
59 ir_variable_refcount_entry *entry = new(mem_ctx) ir_variable_refcount_entry(var);
60 assert(entry->referenced_count == 0);
61 this->variable_list.push_tail(entry);
62 return entry;
63 }
64
65
66 ir_visitor_status
visit(ir_variable * ir)67 ir_variable_refcount_visitor::visit(ir_variable *ir)
68 {
69 ir_variable_refcount_entry *entry = this->get_variable_entry(ir);
70 if (entry)
71 entry->declaration = true;
72
73 return visit_continue;
74 }
75
76
77 ir_visitor_status
visit(ir_dereference_variable * ir)78 ir_variable_refcount_visitor::visit(ir_dereference_variable *ir)
79 {
80 ir_variable *const var = ir->variable_referenced();
81 ir_variable_refcount_entry *entry = this->get_variable_entry(var);
82
83 if (entry)
84 entry->referenced_count++;
85
86 return visit_continue;
87 }
88
89
90 ir_visitor_status
visit_enter(ir_function_signature * ir)91 ir_variable_refcount_visitor::visit_enter(ir_function_signature *ir)
92 {
93 /* We don't want to descend into the function parameters and
94 * dead-code eliminate them, so just accept the body here.
95 */
96 visit_list_elements(this, &ir->body);
97 return visit_continue_with_parent;
98 }
99
100
101 ir_visitor_status
visit_leave(ir_assignment * ir)102 ir_variable_refcount_visitor::visit_leave(ir_assignment *ir)
103 {
104 ir_variable_refcount_entry *entry;
105 entry = this->get_variable_entry(ir->lhs->variable_referenced());
106 if (entry) {
107 entry->assigned_count++;
108 if (entry->assign == NULL)
109 entry->assign = ir;
110 }
111
112 return visit_continue;
113 }
114