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