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 {
  38    this->mem_ctx = ralloc_context(NULL);
  39    this->ht = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
  40                                       _mesa_key_pointer_equal);
  41 }
  42
  43 static void
  44 free_entry(struct hash_entry *entry)
  45 {
  46    ir_array_refcount_entry *ivre = (ir_array_refcount_entry *) entry->data;
  47    delete ivre;
  48 }
  49
  50 ir_array_refcount_visitor::~ir_array_refcount_visitor()
  51 {
  52    ralloc_free(this->mem_ctx);
  53    _mesa_hash_table_destroy(this->ht, free_entry);
  54 }
  55
  56 ir_array_refcount_entry::ir_array_refcount_entry(ir_variable *var)
  57    : var(var), is_referenced(false)
  58 {
  59    num_bits = MAX2(1, var->type->arrays_of_arrays_size());
  60    bits = new BITSET_WORD[BITSET_WORDS(num_bits)];
  61    memset(bits, 0, BITSET_WORDS(num_bits) * sizeof(bits[0]));
  62 }
  63
  64
  65 ir_array_refcount_entry::~ir_array_refcount_entry()
  66 {
  67    delete [] bits;
  68 }
  69
  70
  71 ir_array_refcount_entry *
  72 ir_array_refcount_visitor::get_variable_entry(ir_variable *var)
  73 {
  74    assert(var);
  75
  76    struct hash_entry *e = _mesa_hash_table_search(this->ht, var);
  77    if (e)
  78       return (ir_array_refcount_entry *)e->data;
  79
  80    ir_array_refcount_entry *entry = new ir_array_refcount_entry(var);
  81    _mesa_hash_table_insert(this->ht, var, entry);
  82
  83    return entry;
  84 }
  85
  86
  87 ir_visitor_status
  88 ir_array_refcount_visitor::visit(ir_dereference_variable *ir)
  89 {
  90    ir_variable *const var = ir->variable_referenced();
  91    ir_array_refcount_entry *entry = this->get_variable_entry(var);
  92
  93    entry->is_referenced = true;
  94
  95    return visit_continue;
  96 }
  97
  98
  99 ir_visitor_status
 100 ir_array_refcount_visitor::visit_enter(ir_function_signature *ir)
 101 {
 102    /* We don't want to descend into the function parameters and
 103     * dead-code eliminate them, so just accept the body here.
 104     */
 105    visit_list_elements(this, &ir->body);
 106    return visit_continue_with_parent;
 107 }