source/glsl/optimize.cpp

   1 #include <msp/core/raii.h>
   2 #include "optimize.h"
   3
   4 using namespace std;
   5
   6 namespace Msp {
   7 namespace GL {
   8 namespace SL {
   9
  10 InlineableFunctionLocator::InlineableFunctionLocator():
  11         in_function(0)
  12 { }
  13
  14 void InlineableFunctionLocator::visit(FunctionCall &call)
  15 {
  16         FunctionDeclaration *def = call.declaration;
  17         if(def)
  18                 def = def->definition;
  19
  20         if(def)
  21         {
  22                 unsigned &count = refcounts[def];
  23                 ++count;
  24                 if(count>1 || def==in_function)
  25                         inlineable.erase(def);
  26         }
  27
  28         TraversingVisitor::visit(call);
  29 }
  30
  31 void InlineableFunctionLocator::visit(FunctionDeclaration &func)
  32 {
  33         unsigned &count = refcounts[func.definition];
  34         if(!count && func.parameters.empty())
  35                 inlineable.insert(func.definition);
  36
  37         SetForScope<FunctionDeclaration *> set(in_function, &func);
  38         TraversingVisitor::visit(func);
  39 }
  40
  41
  42 void InlineDependencyCollector::visit(VariableReference &var)
  43 {
  44         if(var.declaration)
  45         {
  46                 dependencies.insert(var.declaration);
  47                 var.declaration->visit(*this);
  48         }
  49 }
  50
  51 void InlineDependencyCollector::visit(InterfaceBlockReference &iface)
  52 {
  53         if(iface.declaration)
  54         {
  55                 dependencies.insert(iface.declaration);
  56                 iface.declaration->visit(*this);
  57         }
  58 }
  59
  60 void InlineDependencyCollector::visit(FunctionCall &call)
  61 {
  62         if(call.declaration)
  63                 dependencies.insert(call.declaration);
  64         TraversingVisitor::visit(call);
  65 }
  66
  67 void InlineDependencyCollector::visit(VariableDeclaration &var)
  68 {
  69         if(var.type_declaration)
  70         {
  71                 dependencies.insert(var.type_declaration);
  72                 var.type_declaration->visit(*this);
  73         }
  74 }
  75
  76
  77 FunctionInliner::FunctionInliner():
  78         current_function(0),
  79         extract_result(0),
  80         any_inlined(false)
  81 { }
  82
  83 bool FunctionInliner::apply(Stage &s)
  84 {
  85         stage = &s;
  86         inlineable = InlineableFunctionLocator().apply(s);
  87         any_inlined = false;
  88         s.content.visit(*this);
  89         return any_inlined;
  90 }
  91
  92 void FunctionInliner::visit_and_inline(RefPtr<Expression> &ptr)
  93 {
  94         inline_result = 0;
  95         ptr->visit(*this);
  96         if(inline_result)
  97         {
  98                 ptr = inline_result;
  99                 any_inlined = true;
 100         }
 101 }
 102
 103 void FunctionInliner::visit(Block &block)
 104 {
 105         if(extract_result)
 106                 --extract_result;
 107
 108         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 109         {
 110                 (*i)->visit(*this);
 111                 if(extract_result)
 112                         --extract_result;
 113         }
 114 }
 115
 116 void FunctionInliner::visit(UnaryExpression &unary)
 117 {
 118         visit_and_inline(unary.expression);
 119         inline_result = 0;
 120 }
 121
 122 void FunctionInliner::visit(BinaryExpression &binary)
 123 {
 124         visit_and_inline(binary.left);
 125         visit_and_inline(binary.right);
 126         inline_result = 0;
 127 }
 128
 129 void FunctionInliner::visit(MemberAccess &memacc)
 130 {
 131         visit_and_inline(memacc.left);
 132         inline_result = 0;
 133 }
 134
 135 void FunctionInliner::visit(FunctionCall &call)
 136 {
 137         for(NodeArray<Expression>::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++i)
 138                 visit_and_inline(*i);
 139
 140         FunctionDeclaration *def = call.declaration;
 141         if(def)
 142                 def = def->definition;
 143
 144         if(def && inlineable.count(def))
 145         {
 146                 extract_result = 2;
 147                 def->visit(*this);
 148
 149                 if(inline_result)
 150                         NodeReorderer().apply(*stage, *current_function, InlineDependencyCollector().apply(*def));
 151         }
 152         else
 153                 inline_result = 0;
 154 }
 155
 156 void FunctionInliner::visit(VariableDeclaration &var)
 157 {
 158         if(var.init_expression)
 159                 visit_and_inline(var.init_expression);
 160         inline_result = 0;
 161 }
 162
 163 void FunctionInliner::visit(FunctionDeclaration &func)
 164 {
 165         SetForScope<FunctionDeclaration *> set_func(current_function, &func);
 166         TraversingVisitor::visit(func);
 167 }
 168
 169 void FunctionInliner::visit(Return &ret)
 170 {
 171         TraversingVisitor::visit(ret);
 172
 173         if(extract_result)
 174                 inline_result = ret.expression->clone();
 175 }
 176
 177
 178 ConstantConditionEliminator::ConstantConditionEliminator():
 179         record_only(false)
 180 { }
 181
 182 void ConstantConditionEliminator::apply(Stage &stage)
 183 {
 184         stage.content.visit(*this);
 185         NodeRemover().apply(stage, nodes_to_remove);
 186 }
 187
 188 void ConstantConditionEliminator::visit(Block &block)
 189 {
 190         SetForScope<Block *> set_block(current_block, &block);
 191         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 192         {
 193                 insert_point = i;
 194                 (*i)->visit(*this);
 195         }
 196
 197         for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
 198                 variable_values.erase(i->second);
 199 }
 200
 201 void ConstantConditionEliminator::visit(UnaryExpression &unary)
 202 {
 203         if(VariableReference *var = dynamic_cast<VariableReference *>(unary.expression.get()))
 204                 if(unary.oper=="++" || unary.oper=="--")
 205                         variable_values.erase(var->declaration);
 206 }
 207
 208 void ConstantConditionEliminator::visit(Assignment &assign)
 209 {
 210         variable_values.erase(assign.target_declaration);
 211 }
 212
 213 void ConstantConditionEliminator::visit(VariableDeclaration &var)
 214 {
 215         bool constant = var.constant;
 216         if(constant && var.layout)
 217         {
 218                 for(vector<Layout::Qualifier>::const_iterator i=var.layout->qualifiers.begin(); (constant && i!=var.layout->qualifiers.end()); ++i)
 219                         constant = (i->name!="constant_id");
 220         }
 221         if((constant || current_block->parent) && var.init_expression)
 222                 variable_values[&var] = var.init_expression.get();
 223 }
 224
 225 void ConstantConditionEliminator::visit(Conditional &cond)
 226 {
 227         if(!record_only)
 228         {
 229                 ExpressionEvaluator eval(variable_values);
 230                 cond.condition->visit(eval);
 231                 if(eval.is_result_valid())
 232                 {
 233                         Block &block = (eval.get_result() ? cond.body : cond.else_body);
 234                         current_block->body.splice(insert_point, block.body);
 235                         nodes_to_remove.insert(&cond);
 236                         return;
 237                 }
 238         }
 239
 240         TraversingVisitor::visit(cond);
 241 }
 242
 243 void ConstantConditionEliminator::visit(Iteration &iter)
 244 {
 245         if(!record_only)
 246         {
 247                 if(iter.condition)
 248                 {
 249                         /* If the loop condition is always false on the first iteration, the
 250                         entire loop can be removed */
 251                         if(iter.init_statement)
 252                                 iter.init_statement->visit(*this);
 253                         ExpressionEvaluator eval(variable_values);
 254                         iter.condition->visit(eval);
 255                         if(eval.is_result_valid() && !eval.get_result())
 256                         {
 257                                 nodes_to_remove.insert(&iter);
 258                                 return;
 259                         }
 260                 }
 261
 262                 /* Record all assignments that occur inside the loop body so those
 263                 variables won't be considered as constant */
 264                 SetFlag set_record(record_only);
 265                 TraversingVisitor::visit(iter);
 266         }
 267
 268         TraversingVisitor::visit(iter);
 269
 270         if(VariableDeclaration *init_decl = dynamic_cast<VariableDeclaration *>(iter.init_statement.get()))
 271                 variable_values.erase(init_decl);
 272 }
 273
 274
 275 UnusedVariableRemover::VariableInfo::VariableInfo():
 276         local(false),
 277         conditionally_assigned(false),
 278         referenced(false)
 279 { }
 280
 281
 282 UnusedVariableRemover::UnusedVariableRemover():
 283         aggregate(0),
 284         assignment(0),
 285         assignment_target(false),
 286         assign_to_subscript(false)
 287 { }
 288
 289 bool UnusedVariableRemover::apply(Stage &stage)
 290 {
 291         variables.push_back(BlockVariableMap());
 292         stage.content.visit(*this);
 293         BlockVariableMap &global_variables = variables.back();
 294         for(BlockVariableMap::iterator i=global_variables.begin(); i!=global_variables.end(); ++i)
 295         {
 296                 if(i->first->interface=="out" && (stage.type==Stage::FRAGMENT || i->first->linked_declaration || !i->first->name.compare(0, 3, "gl_")))
 297                         continue;
 298                 if(!i->second.referenced)
 299                 {
 300                         unused_nodes.insert(i->first);
 301                         clear_assignments(i->second, true);
 302                 }
 303         }
 304         variables.pop_back();
 305
 306         NodeRemover().apply(stage, unused_nodes);
 307
 308         return !unused_nodes.empty();
 309 }
 310
 311 void UnusedVariableRemover::visit(VariableReference &var)
 312 {
 313         map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
 314         if(i!=aggregates.end())
 315                 unused_nodes.erase(i->second);
 316
 317         if(var.declaration && !assignment_target)
 318         {
 319                 VariableInfo &var_info = variables.back()[var.declaration];
 320                 clear_assignments(var_info, false);
 321                 var_info.referenced = true;
 322         }
 323 }
 324
 325 void UnusedVariableRemover::visit(InterfaceBlockReference &iface)
 326 {
 327         unused_nodes.erase(iface.declaration);
 328 }
 329
 330 void UnusedVariableRemover::visit(MemberAccess &memacc)
 331 {
 332         TraversingVisitor::visit(memacc);
 333         unused_nodes.erase(memacc.declaration);
 334 }
 335
 336 void UnusedVariableRemover::visit(BinaryExpression &binary)
 337 {
 338         if(binary.oper=="[")
 339         {
 340                 if(assignment_target)
 341                         assign_to_subscript = true;
 342                 binary.left->visit(*this);
 343                 SetForScope<bool> set(assignment_target, false);
 344                 binary.right->visit(*this);
 345         }
 346         else
 347                 TraversingVisitor::visit(binary);
 348 }
 349
 350 void UnusedVariableRemover::visit(Assignment &assign)
 351 {
 352         {
 353                 assign_to_subscript = false;
 354                 SetForScope<bool> set(assignment_target, !assign.self_referencing);
 355                 assign.left->visit(*this);
 356         }
 357         assign.right->visit(*this);
 358         assignment = &assign;
 359 }
 360
 361 void UnusedVariableRemover::record_assignment(VariableDeclaration &var, Node &node, bool chained)
 362 {
 363         VariableInfo &var_info = variables.back()[&var];
 364         if(!chained)
 365                 clear_assignments(var_info, true);
 366         var_info.assignments.push_back(&node);
 367         var_info.conditionally_assigned = false;
 368 }
 369
 370 void UnusedVariableRemover::clear_assignments(VariableInfo &var_info, bool mark_unused)
 371 {
 372         if(mark_unused)
 373         {
 374                 for(vector<Node *>::iterator i=var_info.assignments.begin(); i!=var_info.assignments.end(); ++i)
 375                         unused_nodes.insert(*i);
 376         }
 377         var_info.assignments.clear();
 378 }
 379
 380 void UnusedVariableRemover::visit(ExpressionStatement &expr)
 381 {
 382         assignment = 0;
 383         TraversingVisitor::visit(expr);
 384         if(assignment && assignment->target_declaration)
 385                 record_assignment(*assignment->target_declaration, expr, (assignment->self_referencing || assign_to_subscript));
 386 }
 387
 388 void UnusedVariableRemover::visit(StructDeclaration &strct)
 389 {
 390         SetForScope<Node *> set(aggregate, &strct);
 391         unused_nodes.insert(&strct);
 392         TraversingVisitor::visit(strct);
 393 }
 394
 395 void UnusedVariableRemover::visit(VariableDeclaration &var)
 396 {
 397         if(aggregate)
 398                 aggregates[&var] = aggregate;
 399         else
 400         {
 401                 variables.back()[&var].local = true;
 402                 if(var.init_expression)
 403                         record_assignment(var, *var.init_expression, false);
 404         }
 405         unused_nodes.erase(var.type_declaration);
 406         TraversingVisitor::visit(var);
 407 }
 408
 409 void UnusedVariableRemover::visit(InterfaceBlock &iface)
 410 {
 411         SetForScope<Node *> set(aggregate, &iface);
 412         unused_nodes.insert(&iface);
 413         TraversingVisitor::visit(iface);
 414 }
 415
 416 void UnusedVariableRemover::visit(FunctionDeclaration &func)
 417 {
 418         variables.push_back(BlockVariableMap());
 419
 420         for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 421                 (*i)->visit(*this);
 422         func.body.visit(*this);
 423
 424         BlockVariableMap &block_variables = variables.back();
 425         for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
 426                 i->second.conditionally_assigned = true;
 427         for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 428                 block_variables[i->get()].referenced = true;
 429         merge_down_variables();
 430 }
 431
 432 void UnusedVariableRemover::merge_down_variables()
 433 {
 434         BlockVariableMap &parent_variables = variables[variables.size()-2];
 435         BlockVariableMap &block_variables = variables.back();
 436         for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
 437         {
 438                 if(i->second.local)
 439                 {
 440                         if(!i->second.referenced)
 441                                 unused_nodes.insert(i->first);
 442                         clear_assignments(i->second, i->first->interface!="out");
 443                         continue;
 444                 }
 445
 446                 BlockVariableMap::iterator j = parent_variables.find(i->first);
 447                 if(j==parent_variables.end())
 448                         parent_variables.insert(*i);
 449                 else
 450                 {
 451                         if(i->second.referenced || !i->second.conditionally_assigned)
 452                                 clear_assignments(j->second, !i->second.referenced);
 453                         j->second.conditionally_assigned = i->second.conditionally_assigned;
 454                         j->second.referenced |= i->second.referenced;
 455                         j->second.assignments.insert(j->second.assignments.end(), i->second.assignments.begin(), i->second.assignments.end());
 456                 }
 457         }
 458         variables.pop_back();
 459 }
 460
 461 void UnusedVariableRemover::visit(Conditional &cond)
 462 {
 463         cond.condition->visit(*this);
 464         variables.push_back(BlockVariableMap());
 465         cond.body.visit(*this);
 466
 467         BlockVariableMap if_variables;
 468         swap(variables.back(), if_variables);
 469         cond.else_body.visit(*this);
 470
 471         BlockVariableMap &else_variables = variables.back();
 472         for(BlockVariableMap::iterator i=else_variables.begin(); i!=else_variables.end(); ++i)
 473         {
 474                 BlockVariableMap::iterator j = if_variables.find(i->first);
 475                 if(j!=if_variables.end())
 476                 {
 477                         i->second.assignments.insert(i->second.assignments.end(), j->second.assignments.begin(), j->second.assignments.end());
 478                         i->second.conditionally_assigned |= j->second.conditionally_assigned;
 479                         if_variables.erase(j);
 480                 }
 481                 else
 482                         i->second.conditionally_assigned = true;
 483         }
 484
 485         for(BlockVariableMap::iterator i=if_variables.begin(); i!=if_variables.end(); ++i)
 486         {
 487                 i->second.conditionally_assigned = true;
 488                 else_variables.insert(*i);
 489         }
 490
 491         merge_down_variables();
 492 }
 493
 494 void UnusedVariableRemover::visit(Iteration &iter)
 495 {
 496         variables.push_back(BlockVariableMap());
 497         TraversingVisitor::visit(iter);
 498
 499         BlockVariableMap &block_variables = variables.back();
 500         for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
 501                 if(!i->second.local && i->second.referenced)
 502                         clear_assignments(i->second, false);
 503
 504         merge_down_variables();
 505 }
 506
 507
 508 bool UnusedFunctionRemover::apply(Stage &stage)
 509 {
 510         stage.content.visit(*this);
 511         NodeRemover().apply(stage, unused_nodes);
 512         return !unused_nodes.empty();
 513 }
 514
 515 void UnusedFunctionRemover::visit(FunctionCall &call)
 516 {
 517         TraversingVisitor::visit(call);
 518
 519         unused_nodes.erase(call.declaration);
 520         if(call.declaration && call.declaration->definition!=call.declaration)
 521                 used_definitions.insert(call.declaration->definition);
 522 }
 523
 524 void UnusedFunctionRemover::visit(FunctionDeclaration &func)
 525 {
 526         TraversingVisitor::visit(func);
 527
 528         if((func.name!="main" || func.body.body.empty()) && !used_definitions.count(&func))
 529                 unused_nodes.insert(&func);
 530 }
 531
 532 } // namespace SL
 533 } // namespace GL
 534 } // namespace Msp