src/intel/compiler/brw_fs_live_variables.h

   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
  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;
  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 */