1 /*
2  * Copyright © 2016 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"),
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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
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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_array_refcount.h
26  *
27  * Provides a visitor which produces a list of variables referenced.
28  */
29 
30 #ifndef GLSL_IR_ARRAY_REFCOUNT_H
31 #define GLSL_IR_ARRAY_REFCOUNT_H
32 
33 #include "ir.h"
34 #include "ir_visitor.h"
35 #include "linker_util.h"
36 #include "compiler/glsl_types.h"
37 #include "util/bitset.h"
38 
39 class ir_array_refcount_entry
40 {
41 public:
42    ir_array_refcount_entry(ir_variable *var);
43    ~ir_array_refcount_entry();
44 
45    ir_variable *var; /* The key: the variable's pointer. */
46 
47    /** Has the variable been referenced? */
48    bool is_referenced;
49 
50    /** Count of nested arrays in the type. */
51    unsigned array_depth;
52 
53    /** Set of bit-flags to note which array elements have been accessed. */
54    BITSET_WORD *bits;
55 
56    /** Has a linearized array index been referenced? */
is_linearized_index_referenced(unsigned linearized_index)57    bool is_linearized_index_referenced(unsigned linearized_index) const
58    {
59       assert(bits != 0);
60       assert(linearized_index <= num_bits);
61 
62       return BITSET_TEST(bits, linearized_index);
63    }
64 
65 private:
66 
67    /**
68     * Total number of bits referenced by \c bits.
69     *
70     * Also the total number of array(s-of-arrays) elements of \c var.
71     */
72    unsigned num_bits;
73 
74    friend class array_refcount_test;
75 };
76 
77 class ir_array_refcount_visitor : public ir_hierarchical_visitor {
78 public:
79    ir_array_refcount_visitor(void);
80    ~ir_array_refcount_visitor(void);
81 
82    virtual ir_visitor_status visit(ir_dereference_variable *);
83 
84    virtual ir_visitor_status visit_enter(ir_function_signature *);
85    virtual ir_visitor_status visit_enter(ir_dereference_array *);
86 
87    /**
88     * Find variable in the hash table, and insert it if not present
89     */
90    ir_array_refcount_entry *get_variable_entry(ir_variable *var);
91 
92    /**
93     * Hash table mapping ir_variable to ir_array_refcount_entry.
94     */
95    struct hash_table *ht;
96 
97    void *mem_ctx;
98 
99 private:
100    /** Get an array_deref_range element from private tracking. */
101    array_deref_range *get_array_deref();
102 
103    /**
104     * Last ir_dereference_array that was visited
105     *
106     * Used to prevent some redundant calculations.
107     *
108     * \sa ::visit_enter(ir_dereference_array *)
109     */
110    ir_dereference_array *last_array_deref;
111 
112    /**
113     * \name array_deref_range tracking
114     */
115    /*@{*/
116    /** Currently allocated block of derefs. */
117    array_deref_range *derefs;
118 
119    /** Number of derefs used in current processing. */
120    unsigned num_derefs;
121 
122    /** Size of the derefs buffer in bytes. */
123    unsigned derefs_size;
124    /*@}*/
125 };
126 
127 #endif /* GLSL_IR_ARRAY_REFCOUNT_H */
128