src/compiler/glsl/ir_array_refcount.h

   1 /*
   2  * Copyright © 2016 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
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file ir_array_refcount.h
  26  *
  27  * Provides a visitor which produces a list of variables referenced.
  28  */
  29
  30 #include "ir.h"
  31 #include "ir_visitor.h"
  32 #include "compiler/glsl_types.h"
  33 #include "util/bitset.h"
  34
  35 /**
  36  * Describes an access of an array element or an access of the whole array
  37  */
  38 struct array_deref_range {
  39    /**
  40     * Index that was accessed.
  41     *
  42     * All valid array indices are less than the size of the array.  If index
  43     * is equal to the size of the array, this means the entire array has been
  44     * accessed (e.g., due to use of a non-constant index).
  45     */
  46    unsigned index;
  47
  48    /** Size of the array.  Used for offset calculations. */
  49    unsigned size;
  50 };
  51
  52 class ir_array_refcount_entry
  53 {
  54 public:
  55    ir_array_refcount_entry(ir_variable *var);
  56    ~ir_array_refcount_entry();
  57
  58    ir_variable *var; /* The key: the variable's pointer. */
  59
  60    /** Has the variable been referenced? */
  61    bool is_referenced;
  62
  63    /** Has a linearized array index been referenced? */
  64    bool is_linearized_index_referenced(unsigned linearized_index) const
  65    {
  66       assert(bits != 0);
  67       assert(linearized_index <= num_bits);
  68
  69       return BITSET_TEST(bits, linearized_index);
  70    }
  71
  72 private:
  73    /** Set of bit-flags to note which array elements have been accessed. */
  74    BITSET_WORD *bits;
  75
  76    /**
  77     * Total number of bits referenced by \c bits.
  78     *
  79     * Also the total number of array(s-of-arrays) elements of \c var.
  80     */
  81    unsigned num_bits;
  82
  83    friend class array_refcount_test;
  84 };
  85
  86 class ir_array_refcount_visitor : public ir_hierarchical_visitor {
  87 public:
  88    ir_array_refcount_visitor(void);
  89    ~ir_array_refcount_visitor(void);
  90
  91    virtual ir_visitor_status visit(ir_dereference_variable *);
  92
  93    virtual ir_visitor_status visit_enter(ir_function_signature *);
  94
  95    /**
  96     * Find variable in the hash table, and insert it if not present
  97     */
  98    ir_array_refcount_entry *get_variable_entry(ir_variable *var);
  99
 100    /**
 101     * Hash table mapping ir_variable to ir_array_refcount_entry.
 102     */
 103    struct hash_table *ht;
 104
 105    void *mem_ctx;
 106
 107 private:
 108    /** Get an array_deref_range element from private tracking. */
 109    array_deref_range *get_array_deref();
 110
 111    /**
 112     * \name array_deref_range tracking
 113     */
 114    /*@{*/
 115    /** Currently allocated block of derefs. */
 116    array_deref_range *derefs;
 117
 118    /** Number of derefs used in current processing. */
 119    unsigned num_derefs;
 120
 121    /** Size of the derefs buffer in bytes. */
 122    unsigned derefs_size;
 123    /*@}*/
 124 };