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