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1 /*
2  * Copyright © 2012 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 DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <eric@anholt.net>
25  *
26  */
27 
28 #ifndef BRW_FS_LIVE_VARIABLES_H
29 #define BRW_FS_LIVE_VARIABLES_H
30 
31 #include "brw_ir_analysis.h"
32 #include "brw_ir_fs.h"
33 #include "util/bitset.h"
34 
35 struct cfg_t;
36 struct backend_shader;
37 
38 namespace brw {
39 
40 class fs_live_variables {
41 public:
42    struct block_data {
43       /**
44        * Which variables are defined before being used in the block.
45        *
46        * Note that for our purposes, "defined" means unconditionally, completely
47        * defined.
48        */
49       BITSET_WORD *def;
50 
51       /**
52        * Which variables are used before being defined in the block.
53        */
54       BITSET_WORD *use;
55 
56       /** Which defs reach the entry point of the block. */
57       BITSET_WORD *livein;
58 
59       /** Which defs reach the exit point of the block. */
60       BITSET_WORD *liveout;
61 
62       /**
63        * Variables such that the entry point of the block may be reached from any
64        * of their definitions.
65        */
66       BITSET_WORD *defin;
67 
68       /**
69        * Variables such that the exit point of the block may be reached from any
70        * of their definitions.
71        */
72       BITSET_WORD *defout;
73 
74       BITSET_WORD flag_def[1];
75       BITSET_WORD flag_use[1];
76       BITSET_WORD flag_livein[1];
77       BITSET_WORD flag_liveout[1];
78    };
79 
80    fs_live_variables(const backend_shader *s);
81    ~fs_live_variables();
82 
83    bool validate(const backend_shader *s) const;
84 
85    analysis_dependency_class
dependency_class()86    dependency_class() const
87    {
88       return (DEPENDENCY_INSTRUCTION_IDENTITY |
89               DEPENDENCY_INSTRUCTION_DATA_FLOW |
90               DEPENDENCY_VARIABLES);
91    }
92 
93    bool vars_interfere(int a, int b) const;
94    bool vgrfs_interfere(int a, int b) const;
var_from_reg(const fs_reg & reg)95    int var_from_reg(const fs_reg &reg) const
96    {
97       return var_from_vgrf[reg.nr] + reg.offset / REG_SIZE;
98    }
99 
100    /** Map from virtual GRF number to index in block_data arrays. */
101    int *var_from_vgrf;
102 
103    /**
104     * Map from any index in block_data to the virtual GRF containing it.
105     *
106     * For alloc.sizes of [1, 2, 3], vgrf_from_var would contain
107     * [0, 1, 1, 2, 2, 2].
108     */
109    int *vgrf_from_var;
110 
111    int num_vars;
112    int num_vgrfs;
113    int bitset_words;
114 
115    /** @{
116     * Final computed live ranges for each var (each component of each virtual
117     * GRF).
118     */
119    int *start;
120    int *end;
121    /** @} */
122 
123    /** @{
124     * Final computed live ranges for each VGRF.
125     */
126    int *vgrf_start;
127    int *vgrf_end;
128    /** @} */
129 
130    /** Per-basic-block information on live variables */
131    struct block_data *block_data;
132 
133 protected:
134    void setup_def_use();
135    void setup_one_read(struct block_data *bd, int ip, const fs_reg &reg);
136    void setup_one_write(struct block_data *bd, fs_inst *inst, int ip,
137                         const fs_reg &reg);
138    void compute_live_variables();
139    void compute_start_end();
140 
141    const struct gen_device_info *devinfo;
142    const cfg_t *cfg;
143    void *mem_ctx;
144 };
145 
146 } /* namespace brw */
147 
148 #endif /* BRW_FS_LIVE_VARIABLES_H */
149