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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 (at) anholt.net>
     25  *
     26  */
     27 
     28 #include "brw_fs.h"
     29 #include "util/bitset.h"
     30 
     31 struct cfg_t;
     32 
     33 namespace brw {
     34 
     35 struct block_data {
     36    /**
     37     * Which variables are defined before being used in the block.
     38     *
     39     * Note that for our purposes, "defined" means unconditionally, completely
     40     * defined.
     41     */
     42    BITSET_WORD *def;
     43 
     44    /**
     45     * Which variables are used before being defined in the block.
     46     */
     47    BITSET_WORD *use;
     48 
     49    /** Which defs reach the entry point of the block. */
     50    BITSET_WORD *livein;
     51 
     52    /** Which defs reach the exit point of the block. */
     53    BITSET_WORD *liveout;
     54 
     55    BITSET_WORD flag_def[1];
     56    BITSET_WORD flag_use[1];
     57    BITSET_WORD flag_livein[1];
     58    BITSET_WORD flag_liveout[1];
     59 };
     60 
     61 class fs_live_variables {
     62 public:
     63    DECLARE_RALLOC_CXX_OPERATORS(fs_live_variables)
     64 
     65    fs_live_variables(fs_visitor *v, const cfg_t *cfg);
     66    ~fs_live_variables();
     67 
     68    bool vars_interfere(int a, int b);
     69    int var_from_reg(const fs_reg &reg) const
     70    {
     71       return var_from_vgrf[reg.nr] + reg.offset / REG_SIZE;
     72    }
     73 
     74    /** Map from virtual GRF number to index in block_data arrays. */
     75    int *var_from_vgrf;
     76 
     77    /**
     78     * Map from any index in block_data to the virtual GRF containing it.
     79     *
     80     * For alloc.sizes of [1, 2, 3], vgrf_from_var would contain
     81     * [0, 1, 1, 2, 2, 2].
     82     */
     83    int *vgrf_from_var;
     84 
     85    int num_vars;
     86    int num_vgrfs;
     87    int bitset_words;
     88 
     89    /** @{
     90     * Final computed live ranges for each var (each component of each virtual
     91     * GRF).
     92     */
     93    int *start;
     94    int *end;
     95    /** @} */
     96 
     97    /** Per-basic-block information on live variables */
     98    struct block_data *block_data;
     99 
    100 protected:
    101    void setup_def_use();
    102    void setup_one_read(struct block_data *bd, fs_inst *inst, int ip,
    103                        const fs_reg &reg);
    104    void setup_one_write(struct block_data *bd, fs_inst *inst, int ip,
    105                         const fs_reg &reg);
    106    void compute_live_variables();
    107    void compute_start_end();
    108 
    109    fs_visitor *v;
    110    const cfg_t *cfg;
    111    void *mem_ctx;
    112 
    113 };
    114 
    115 } /* namespace brw */
    116