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.h
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#ifndef GLSL_IR_VARIABLE_REFCOUNT_H
33#define GLSL_IR_VARIABLE_REFCOUNT_H
34
35#include "ir.h"
36#include "ir_visitor.h"
37#include "compiler/glsl_types.h"
38
39struct assignment_entry {
40   exec_node link;
41   ir_assignment *assign;
42};
43
44class ir_variable_refcount_entry
45{
46public:
47   ir_variable_refcount_entry(ir_variable *var);
48
49   ir_variable *var; /* The key: the variable's pointer. */
50
51   /**
52    * List of assignments to the variable, if any.
53    * This is intended to be used for dead code optimisation and may
54    * not be a complete list.
55    */
56   exec_list assign_list;
57
58   /** Number of times the variable is referenced, including assignments. */
59   unsigned referenced_count;
60
61   /** Number of times the variable is assigned. */
62   unsigned assigned_count;
63
64   bool declaration; /* If the variable had a decl in the instruction stream */
65};
66
67class ir_variable_refcount_visitor : public ir_hierarchical_visitor {
68public:
69   ir_variable_refcount_visitor(void);
70   ~ir_variable_refcount_visitor(void);
71
72   virtual ir_visitor_status visit(ir_variable *);
73   virtual ir_visitor_status visit(ir_dereference_variable *);
74
75   virtual ir_visitor_status visit_enter(ir_function_signature *);
76   virtual ir_visitor_status visit_leave(ir_assignment *);
77
78   /**
79    * Find variable in the hash table, and insert it if not present
80    */
81   ir_variable_refcount_entry *get_variable_entry(ir_variable *var);
82
83   /**
84    * Hash table mapping ir_variable to ir_variable_refcount_entry.
85    */
86   struct hash_table *ht;
87
88   void *mem_ctx;
89};
90
91#endif /* GLSL_IR_VARIABLE_REFCOUNT_H */
92