src/compiler/glsl/ir_array_refcount.cpp

   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.cpp
  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 "ir_array_refcount.h"
  33 #include "compiler/glsl_types.h"
  34 #include "util/hash_table.h"
  35
  36 ir_array_refcount_visitor::ir_array_refcount_visitor()
  37    : derefs(0), num_derefs(0), derefs_size(0)
  38 {
  39    this->mem_ctx = ralloc_context(NULL);
  40    this->ht = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
  41                                       _mesa_key_pointer_equal);
  42 }
  43
  44 static void
  45 free_entry(struct hash_entry *entry)
  46 {
  47    ir_array_refcount_entry *ivre = (ir_array_refcount_entry *) entry->data;
  48    delete ivre;
  49 }
  50
  51 ir_array_refcount_visitor::~ir_array_refcount_visitor()
  52 {
  53    ralloc_free(this->mem_ctx);
  54    _mesa_hash_table_destroy(this->ht, free_entry);
  55 }
  56
  57 ir_array_refcount_entry::ir_array_refcount_entry(ir_variable *var)
  58    : var(var), is_referenced(false)
  59 {
  60    num_bits = MAX2(1, var->type->arrays_of_arrays_size());
  61    bits = new BITSET_WORD[BITSET_WORDS(num_bits)];
  62    memset(bits, 0, BITSET_WORDS(num_bits) * sizeof(bits[0]));
  63 }
  64
  65
  66 ir_array_refcount_entry::~ir_array_refcount_entry()
  67 {
  68    delete [] bits;
  69 }
  70
  71
  72 ir_array_refcount_entry *
  73 ir_array_refcount_visitor::get_variable_entry(ir_variable *var)
  74 {
  75    assert(var);
  76
  77    struct hash_entry *e = _mesa_hash_table_search(this->ht, var);
  78    if (e)
  79       return (ir_array_refcount_entry *)e->data;
  80
  81    ir_array_refcount_entry *entry = new ir_array_refcount_entry(var);
  82    _mesa_hash_table_insert(this->ht, var, entry);
  83
  84    return entry;
  85 }
  86
  87
  88 array_deref_range *
  89 ir_array_refcount_visitor::get_array_deref()
  90 {
  91    if ((num_derefs + 1) * sizeof(array_deref_range) > derefs_size) {
  92       void *ptr = reralloc_size(mem_ctx, derefs, derefs_size + 4096);
  93
  94       if (ptr == NULL)
  95          return NULL;
  96
  97       derefs_size += 4096;
  98       derefs = (array_deref_range *)ptr;
  99    }
 100
 101    array_deref_range *d = &derefs[num_derefs];
 102    num_derefs++;
 103
 104    return d;
 105 }
 106
 107
 108 ir_visitor_status
 109 ir_array_refcount_visitor::visit(ir_dereference_variable *ir)
 110 {
 111    ir_variable *const var = ir->variable_referenced();
 112    ir_array_refcount_entry *entry = this->get_variable_entry(var);
 113
 114    entry->is_referenced = true;
 115
 116    return visit_continue;
 117 }
 118
 119
 120 ir_visitor_status
 121 ir_array_refcount_visitor::visit_enter(ir_function_signature *ir)
 122 {
 123    /* We don't want to descend into the function parameters and
 124     * dead-code eliminate them, so just accept the body here.
 125     */
 126    visit_list_elements(this, &ir->body);
 127    return visit_continue_with_parent;
 128 }