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 class fs_visitor;
  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(fs_visitor *v, const cfg_t *cfg);
  82    ~fs_live_variables();
  83
  84    bool vars_interfere(int a, int b) const;
  85    int var_from_reg(const fs_reg &reg) const
  86    {
  87       return var_from_vgrf[reg.nr] + reg.offset / REG_SIZE;
  88    }
  89
  90    /** Map from virtual GRF number to index in block_data arrays. */
  91    int *var_from_vgrf;
  92
  93    /**
  94     * Map from any index in block_data to the virtual GRF containing it.
  95     *
  96     * For alloc.sizes of [1, 2, 3], vgrf_from_var would contain
  97     * [0, 1, 1, 2, 2, 2].
  98     */
  99    int *vgrf_from_var;
 100
 101    int num_vars;
 102    int num_vgrfs;
 103    int bitset_words;
 104
 105    /** @{
 106     * Final computed live ranges for each var (each component of each virtual
 107     * GRF).
 108     */
 109    int *start;
 110    int *end;
 111    /** @} */
 112
 113    /** Per-basic-block information on live variables */
 114    struct block_data *block_data;
 115
 116 protected:
 117    void setup_def_use();
 118    void setup_one_read(struct block_data *bd, fs_inst *inst, int ip,
 119                        const fs_reg &reg);
 120    void setup_one_write(struct block_data *bd, fs_inst *inst, int ip,
 121                         const fs_reg &reg);
 122    void compute_live_variables();
 123    void compute_start_end();
 124
 125    fs_visitor *v;
 126    const cfg_t *cfg;
 127    void *mem_ctx;
 128
 129 };
 130
 131 } /* namespace brw */
 132
 133 #endif /* BRW_FS_LIVE_VARIABLES_H */