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