src/intel/compiler/brw_vec4_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_VEC4_LIVE_VARIABLES_H
  29 #define BRW_VEC4_LIVE_VARIABLES_H
  30
  31 #include "brw_ir_vec4.h"
  32 #include "brw_ir_analysis.h"
  33 #include "util/bitset.h"
  34
  35 struct backend_shader;
  36
  37 namespace brw {
  38
  39 class vec4_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       BITSET_WORD flag_def[1];
  62       BITSET_WORD flag_use[1];
  63       BITSET_WORD flag_livein[1];
  64       BITSET_WORD flag_liveout[1];
  65    };
  66
  67    vec4_live_variables(const backend_shader *s);
  68    ~vec4_live_variables();
  69
  70    bool
  71    validate(const backend_shader *s) const;
  72
  73    analysis_dependency_class
  74    dependency_class() const
  75    {
  76       return (DEPENDENCY_INSTRUCTION_IDENTITY |
  77               DEPENDENCY_INSTRUCTION_DATA_FLOW |
  78               DEPENDENCY_VARIABLES);
  79    }
  80
  81    int num_vars;
  82    int bitset_words;
  83
  84    /** Per-basic-block information on live variables */
  85    struct block_data *block_data;
  86
  87    /** @{
  88     * Final computed live ranges for each variable.
  89     */
  90    int *start;
  91    int *end;
  92    /** @} */
  93
  94    int var_range_start(unsigned v, unsigned n) const;
  95    int var_range_end(unsigned v, unsigned n) const;
  96    bool vgrfs_interfere(int a, int b) const;
  97
  98 protected:
  99    void setup_def_use();
 100    void compute_live_variables();
 101    void compute_start_end();
 102
 103    const simple_allocator &alloc;
 104    cfg_t *cfg;
 105    void *mem_ctx;
 106 };
 107
 108 /* Returns the variable index for the k-th dword of the c-th component of
 109  * register reg.
 110  */
 111 inline unsigned
 112 var_from_reg(const simple_allocator &alloc, const src_reg &reg,
 113              unsigned c = 0, unsigned k = 0)
 114 {
 115    assert(reg.file == VGRF && reg.nr < alloc.count && c < 4);
 116    const unsigned csize = DIV_ROUND_UP(type_sz(reg.type), 4);
 117    unsigned result =
 118       8 * alloc.offsets[reg.nr] + reg.offset / 4 +
 119       (BRW_GET_SWZ(reg.swizzle, c) + k / csize * 4) * csize + k % csize;
 120    /* Do not exceed the limit for this register */
 121    assert(result < 8 * (alloc.offsets[reg.nr] + alloc.sizes[reg.nr]));
 122    return result;
 123 }
 124
 125 inline unsigned
 126 var_from_reg(const simple_allocator &alloc, const dst_reg &reg,
 127              unsigned c = 0, unsigned k = 0)
 128 {
 129    assert(reg.file == VGRF && reg.nr < alloc.count && c < 4);
 130    const unsigned csize = DIV_ROUND_UP(type_sz(reg.type), 4);
 131    unsigned result =
 132       8 * alloc.offsets[reg.nr] + reg.offset / 4 +
 133       (c + k / csize * 4) * csize + k % csize;
 134    /* Do not exceed the limit for this register */
 135    assert(result < 8 * (alloc.offsets[reg.nr] + alloc.sizes[reg.nr]));
 136    return result;
 137 }
 138
 139 } /* namespace brw */
 140
 141 #endif /* BRW_VEC4_LIVE_VARIABLES_H */