src/compiler/glsl/lower_named_interface_blocks.cpp

   1 /*
   2  * Copyright (c) 2013 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 lower_named_interface_blocks.cpp
  26  *
  27  * This lowering pass converts all interface blocks with instance names
  28  * into interface blocks without an instance name.
  29  *
  30  * For example, the following shader:
  31  *
  32  *   out block {
  33  *     float block_var;
  34  *   } inst_name;
  35  *
  36  *   main()
  37  *   {
  38  *     inst_name.block_var = 0.0;
  39  *   }
  40  *
  41  * Is rewritten to:
  42  *
  43  *   out block {
  44  *     float block_var;
  45  *   };
  46  *
  47  *   main()
  48  *   {
  49  *     block_var = 0.0;
  50  *   }
  51  *
  52  * This takes place after the shader code has already been verified with
  53  * the interface name in place.
  54  *
  55  * The linking phase will use the interface block name rather than the
  56  * interface's instance name when linking interfaces.
  57  *
  58  * This modification to the ir allows our currently existing dead code
  59  * elimination to work with interface blocks without changes.
  60  */
  61
  62 #include "glsl_symbol_table.h"
  63 #include "ir.h"
  64 #include "ir_optimization.h"
  65 #include "ir_rvalue_visitor.h"
  66 #include "util/hash_table.h"
  67
  68 static const glsl_type *
  69 process_array_type(const glsl_type *type, unsigned idx)
  70 {
  71    const glsl_type *element_type = type->fields.array;
  72    if (element_type->is_array()) {
  73       const glsl_type *new_array_type = process_array_type(element_type, idx);
  74       return glsl_type::get_array_instance(new_array_type, type->length);
  75    } else {
  76       return glsl_type::get_array_instance(
  77          element_type->fields.structure[idx].type, type->length);
  78    }
  79 }
  80
  81 static ir_rvalue *
  82 process_array_ir(void * const mem_ctx,
  83                  ir_dereference_array *deref_array_prev,
  84                  ir_rvalue *deref_var)
  85 {
  86    ir_dereference_array *deref_array =
  87       deref_array_prev->array->as_dereference_array();
  88
  89    if (deref_array == NULL) {
  90       return new(mem_ctx) ir_dereference_array(deref_var,
  91                                                deref_array_prev->array_index);
  92    } else {
  93       deref_array = (ir_dereference_array *) process_array_ir(mem_ctx,
  94                                                               deref_array,
  95                                                               deref_var);
  96       return new(mem_ctx) ir_dereference_array(deref_array,
  97                                                deref_array_prev->array_index);
  98    }
  99 }
 100
 101 namespace {
 102
 103 class flatten_named_interface_blocks_declarations : public ir_rvalue_visitor
 104 {
 105 public:
 106    void * const mem_ctx;
 107    hash_table *interface_namespace;
 108
 109    flatten_named_interface_blocks_declarations(void *mem_ctx)
 110       : mem_ctx(mem_ctx),
 111         interface_namespace(NULL)
 112    {
 113    }
 114
 115    void run(exec_list *instructions);
 116
 117    virtual ir_visitor_status visit_leave(ir_assignment *);
 118    virtual void handle_rvalue(ir_rvalue **rvalue);
 119 };
 120
 121 } /* anonymous namespace */
 122
 123 void
 124 flatten_named_interface_blocks_declarations::run(exec_list *instructions)
 125 {
 126    interface_namespace = _mesa_hash_table_create(NULL, _mesa_key_hash_string,
 127                                                  _mesa_key_string_equal);
 128
 129    /* First pass: adjust instance block variables with an instance name
 130     * to not have an instance name.
 131     *
 132     * The interface block variables are stored in the interface_namespace
 133     * hash table so they can be used in the second pass.
 134     */
 135    foreach_in_list_safe(ir_instruction, node, instructions) {
 136       ir_variable *var = node->as_variable();
 137       if (!var || !var->is_interface_instance())
 138          continue;
 139
 140       /* It should be possible to handle uniforms during this pass,
 141        * but, this will require changes to the other uniform block
 142        * support code.
 143        */
 144       if (var->data.mode == ir_var_uniform ||
 145           var->data.mode == ir_var_shader_storage)
 146          continue;
 147
 148       const glsl_type * iface_t = var->type->without_array();
 149       exec_node *insert_pos = var;
 150
 151       assert (iface_t->is_interface());
 152
 153       for (unsigned i = 0; i < iface_t->length; i++) {
 154          const char * field_name = iface_t->fields.structure[i].name;
 155          char *iface_field_name =
 156             ralloc_asprintf(mem_ctx, "%s %s.%s.%s",
 157                             var->data.mode == ir_var_shader_in ? "in" : "out",
 158                             iface_t->name, var->name, field_name);
 159
 160          hash_entry *entry = _mesa_hash_table_search(interface_namespace,
 161                                                      iface_field_name);
 162          ir_variable *found_var = entry ? (ir_variable *) entry->data : NULL;
 163          if (!found_var) {
 164             ir_variable *new_var;
 165             char *var_name =
 166                ralloc_strdup(mem_ctx, iface_t->fields.structure[i].name);
 167             if (!var->type->is_array()) {
 168                new_var =
 169                   new(mem_ctx) ir_variable(iface_t->fields.structure[i].type,
 170                                            var_name,
 171                                            (ir_variable_mode) var->data.mode);
 172             } else {
 173                const glsl_type *new_array_type =
 174                   process_array_type(var->type, i);
 175                new_var =
 176                   new(mem_ctx) ir_variable(new_array_type,
 177                                            var_name,
 178                                            (ir_variable_mode) var->data.mode);
 179             }
 180             new_var->data.location = iface_t->fields.structure[i].location;
 181             new_var->data.explicit_location = (new_var->data.location >= 0);
 182             new_var->data.offset = iface_t->fields.structure[i].offset;
 183             new_var->data.explicit_xfb_offset =
 184                (iface_t->fields.structure[i].offset >= 0);
 185             new_var->data.xfb_buffer =
 186                iface_t->fields.structure[i].xfb_buffer;
 187             new_var->data.explicit_xfb_buffer =
 188                iface_t->fields.structure[i].explicit_xfb_buffer;
 189             new_var->data.interpolation =
 190                iface_t->fields.structure[i].interpolation;
 191             new_var->data.centroid = iface_t->fields.structure[i].centroid;
 192             new_var->data.sample = iface_t->fields.structure[i].sample;
 193             new_var->data.patch = iface_t->fields.structure[i].patch;
 194             new_var->data.stream = var->data.stream;
 195             new_var->data.how_declared = var->data.how_declared;
 196             new_var->data.from_named_ifc_block = 1;
 197
 198             new_var->init_interface_type(var->type);
 199             _mesa_hash_table_insert(interface_namespace, iface_field_name,
 200                                     new_var);
 201             insert_pos->insert_after(new_var);
 202             insert_pos = new_var;
 203          }
 204       }
 205       var->remove();
 206    }
 207
 208    /* Second pass: visit all ir_dereference_record instances, and if they
 209     * reference an interface block, then flatten the refererence out.
 210     */
 211    visit_list_elements(this, instructions);
 212    _mesa_hash_table_destroy(interface_namespace, NULL);
 213    interface_namespace = NULL;
 214 }
 215
 216 ir_visitor_status
 217 flatten_named_interface_blocks_declarations::visit_leave(ir_assignment *ir)
 218 {
 219    ir_dereference_record *lhs_rec = ir->lhs->as_dereference_record();
 220
 221    ir_variable *lhs_var =  ir->lhs->variable_referenced();
 222    if (lhs_var && lhs_var->get_interface_type()) {
 223       lhs_var->data.assigned = 1;
 224    }
 225
 226    if (lhs_rec) {
 227       ir_rvalue *lhs_rec_tmp = lhs_rec;
 228       handle_rvalue(&lhs_rec_tmp);
 229       if (lhs_rec_tmp != lhs_rec) {
 230          ir->set_lhs(lhs_rec_tmp);
 231       }
 232
 233       ir_variable *lhs_var =  lhs_rec_tmp->variable_referenced();
 234       if (lhs_var) {
 235          lhs_var->data.assigned = 1;
 236       }
 237    }
 238    return rvalue_visit(ir);
 239 }
 240
 241 void
 242 flatten_named_interface_blocks_declarations::handle_rvalue(ir_rvalue **rvalue)
 243 {
 244    if (*rvalue == NULL)
 245       return;
 246
 247    ir_dereference_record *ir = (*rvalue)->as_dereference_record();
 248    if (ir == NULL)
 249       return;
 250
 251    ir_variable *var = ir->variable_referenced();
 252    if (var == NULL)
 253       return;
 254
 255    if (!var->is_interface_instance())
 256       return;
 257
 258    /* It should be possible to handle uniforms during this pass,
 259     * but, this will require changes to the other uniform block
 260     * support code.
 261     */
 262    if (var->data.mode == ir_var_uniform || var->data.mode == ir_var_shader_storage)
 263       return;
 264
 265    if (var->get_interface_type() != NULL) {
 266       char *iface_field_name =
 267          ralloc_asprintf(mem_ctx, "%s %s.%s.%s",
 268                          var->data.mode == ir_var_shader_in ? "in" : "out",
 269                          var->get_interface_type()->name,
 270                          var->name, ir->field);
 271
 272       /* Find the variable in the set of flattened interface blocks */
 273       hash_entry *entry = _mesa_hash_table_search(interface_namespace,
 274                                                   iface_field_name);
 275       assert(entry);
 276       ir_variable *found_var = (ir_variable *) entry->data;
 277
 278       ir_dereference_variable *deref_var =
 279          new(mem_ctx) ir_dereference_variable(found_var);
 280
 281       ir_dereference_array *deref_array =
 282          ir->record->as_dereference_array();
 283       if (deref_array != NULL) {
 284          *rvalue = process_array_ir(mem_ctx, deref_array,
 285                                     (ir_rvalue *)deref_var);
 286       } else {
 287          *rvalue = deref_var;
 288       }
 289    }
 290 }
 291
 292 void
 293 lower_named_interface_blocks(void *mem_ctx, gl_linked_shader *shader)
 294 {
 295    flatten_named_interface_blocks_declarations v_decl(mem_ctx);
 296    v_decl.run(shader->ir);
 297 }
 298