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 FunctionInliner::FunctionInliner():
  43         extract_result(0)
  44 { }
  45
  46 void FunctionInliner::apply(Stage &stage)
  47 {
  48         inlineable = InlineableFunctionLocator().apply(stage);
  49         stage.content.visit(*this);
  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)
  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         record_only(false)
 128 { }
 129
 130 void ConstantConditionEliminator::apply(Stage &stage)
 131 {
 132         stage.content.visit(*this);
 133         NodeRemover().apply(stage, nodes_to_remove);
 134 }
 135
 136 void ConstantConditionEliminator::visit(Block &block)
 137 {
 138         SetForScope<Block *> set_block(current_block, &block);
 139         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 140         {
 141                 insert_point = i;
 142                 (*i)->visit(*this);
 143         }
 144
 145         for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
 146                 variable_values.erase(i->second);
 147 }
 148
 149 void ConstantConditionEliminator::visit(UnaryExpression &unary)
 150 {
 151         if(VariableReference *var = dynamic_cast<VariableReference *>(unary.expression.get()))
 152                 if(unary.oper=="++" || unary.oper=="--")
 153                         variable_values.erase(var->declaration);
 154 }
 155
 156 void ConstantConditionEliminator::visit(Assignment &assign)
 157 {
 158         variable_values.erase(assign.target_declaration);
 159 }
 160
 161 void ConstantConditionEliminator::visit(VariableDeclaration &var)
 162 {
 163         bool constant = var.constant;
 164         if(constant && var.layout)
 165         {
 166                 for(vector<Layout::Qualifier>::const_iterator i=var.layout->qualifiers.begin(); (constant && i!=var.layout->qualifiers.end()); ++i)
 167                         constant = (i->name!="constant_id");
 168         }
 169         if((constant || current_block->parent) && var.init_expression)
 170                 variable_values[&var] = var.init_expression.get();
 171 }
 172
 173 void ConstantConditionEliminator::visit(Conditional &cond)
 174 {
 175         if(!record_only)
 176         {
 177                 ExpressionEvaluator eval(variable_values);
 178                 cond.condition->visit(eval);
 179                 if(eval.is_result_valid())
 180                 {
 181                         Block &block = (eval.get_result() ? cond.body : cond.else_body);
 182                         current_block->body.splice(insert_point, block.body);
 183                         nodes_to_remove.insert(&cond);
 184                         return;
 185                 }
 186         }
 187
 188         TraversingVisitor::visit(cond);
 189 }
 190
 191 void ConstantConditionEliminator::visit(Iteration &iter)
 192 {
 193         if(!record_only)
 194         {
 195                 if(iter.condition)
 196                 {
 197                         /* If the loop condition is always false on the first iteration, the
 198                         entire loop can be removed */
 199                         if(iter.init_statement)
 200                                 iter.init_statement->visit(*this);
 201                         ExpressionEvaluator eval(variable_values);
 202                         iter.condition->visit(eval);
 203                         if(eval.is_result_valid() && !eval.get_result())
 204                         {
 205                                 nodes_to_remove.insert(&iter);
 206                                 return;
 207                         }
 208                 }
 209
 210                 /* Record all assignments that occur inside the loop body so those
 211                 variables won't be considered as constant */
 212                 SetFlag set_record(record_only);
 213                 TraversingVisitor::visit(iter);
 214         }
 215
 216         TraversingVisitor::visit(iter);
 217
 218         if(VariableDeclaration *init_decl = dynamic_cast<VariableDeclaration *>(iter.init_statement.get()))
 219                 variable_values.erase(init_decl);
 220 }
 221
 222
 223 UnusedVariableRemover::VariableInfo::VariableInfo():
 224         local(false),
 225         conditionally_assigned(false),
 226         referenced(false)
 227 { }
 228
 229
 230 UnusedVariableRemover::UnusedVariableRemover():
 231         aggregate(0),
 232         assignment(0),
 233         assignment_target(false),
 234         assign_to_subscript(false)
 235 { }
 236
 237 bool UnusedVariableRemover::apply(Stage &stage)
 238 {
 239         variables.push_back(BlockVariableMap());
 240         stage.content.visit(*this);
 241         BlockVariableMap &global_variables = variables.back();
 242         for(BlockVariableMap::iterator i=global_variables.begin(); i!=global_variables.end(); ++i)
 243         {
 244                 if(i->first->interface=="out" && (stage.type==Stage::FRAGMENT || i->first->linked_declaration || !i->first->name.compare(0, 3, "gl_")))
 245                         continue;
 246                 if(!i->second.referenced)
 247                 {
 248                         unused_nodes.insert(i->first);
 249                         clear_assignments(i->second, true);
 250                 }
 251         }
 252         variables.pop_back();
 253
 254         NodeRemover().apply(stage, unused_nodes);
 255
 256         return !unused_nodes.empty();
 257 }
 258
 259 void UnusedVariableRemover::visit(VariableReference &var)
 260 {
 261         map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
 262         if(i!=aggregates.end())
 263                 unused_nodes.erase(i->second);
 264
 265         if(var.declaration && !assignment_target)
 266         {
 267                 VariableInfo &var_info = variables.back()[var.declaration];
 268                 clear_assignments(var_info, false);
 269                 var_info.referenced = true;
 270         }
 271 }
 272
 273 void UnusedVariableRemover::visit(InterfaceBlockReference &iface)
 274 {
 275         unused_nodes.erase(iface.declaration);
 276 }
 277
 278 void UnusedVariableRemover::visit(MemberAccess &memacc)
 279 {
 280         TraversingVisitor::visit(memacc);
 281         unused_nodes.erase(memacc.declaration);
 282 }
 283
 284 void UnusedVariableRemover::visit(BinaryExpression &binary)
 285 {
 286         if(binary.oper=="[")
 287         {
 288                 if(assignment_target)
 289                         assign_to_subscript = true;
 290                 binary.left->visit(*this);
 291                 SetForScope<bool> set(assignment_target, false);
 292                 binary.right->visit(*this);
 293         }
 294         else
 295                 TraversingVisitor::visit(binary);
 296 }
 297
 298 void UnusedVariableRemover::visit(Assignment &assign)
 299 {
 300         {
 301                 assign_to_subscript = false;
 302                 SetForScope<bool> set(assignment_target, !assign.self_referencing);
 303                 assign.left->visit(*this);
 304         }
 305         assign.right->visit(*this);
 306         assignment = &assign;
 307 }
 308
 309 void UnusedVariableRemover::record_assignment(VariableDeclaration &var, Node &node, bool chained)
 310 {
 311         VariableInfo &var_info = variables.back()[&var];
 312         if(!chained)
 313                 clear_assignments(var_info, true);
 314         var_info.assignments.push_back(&node);
 315         var_info.conditionally_assigned = false;
 316 }
 317
 318 void UnusedVariableRemover::clear_assignments(VariableInfo &var_info, bool mark_unused)
 319 {
 320         if(mark_unused)
 321         {
 322                 for(vector<Node *>::iterator i=var_info.assignments.begin(); i!=var_info.assignments.end(); ++i)
 323                         unused_nodes.insert(*i);
 324         }
 325         var_info.assignments.clear();
 326 }
 327
 328 void UnusedVariableRemover::visit(ExpressionStatement &expr)
 329 {
 330         assignment = 0;
 331         TraversingVisitor::visit(expr);
 332         if(assignment && assignment->target_declaration)
 333                 record_assignment(*assignment->target_declaration, expr, (assignment->self_referencing || assign_to_subscript));
 334 }
 335
 336 void UnusedVariableRemover::visit(StructDeclaration &strct)
 337 {
 338         SetForScope<Node *> set(aggregate, &strct);
 339         unused_nodes.insert(&strct);
 340         TraversingVisitor::visit(strct);
 341 }
 342
 343 void UnusedVariableRemover::visit(VariableDeclaration &var)
 344 {
 345         if(aggregate)
 346                 aggregates[&var] = aggregate;
 347         else
 348         {
 349                 variables.back()[&var].local = true;
 350                 if(var.init_expression)
 351                         record_assignment(var, *var.init_expression, false);
 352         }
 353         unused_nodes.erase(var.type_declaration);
 354         TraversingVisitor::visit(var);
 355 }
 356
 357 void UnusedVariableRemover::visit(InterfaceBlock &iface)
 358 {
 359         SetForScope<Node *> set(aggregate, &iface);
 360         unused_nodes.insert(&iface);
 361         TraversingVisitor::visit(iface);
 362 }
 363
 364 void UnusedVariableRemover::visit(FunctionDeclaration &func)
 365 {
 366         variables.push_back(BlockVariableMap());
 367
 368         for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 369                 (*i)->visit(*this);
 370         func.body.visit(*this);
 371
 372         BlockVariableMap &block_variables = variables.back();
 373         for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
 374                 i->second.conditionally_assigned = true;
 375         for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 376                 block_variables[i->get()].referenced = true;
 377         merge_down_variables();
 378 }
 379
 380 void UnusedVariableRemover::merge_down_variables()
 381 {
 382         BlockVariableMap &parent_variables = variables[variables.size()-2];
 383         BlockVariableMap &block_variables = variables.back();
 384         for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
 385         {
 386                 if(i->second.local)
 387                 {
 388                         if(!i->second.referenced)
 389                                 unused_nodes.insert(i->first);
 390                         clear_assignments(i->second, i->first->interface!="out");
 391                         continue;
 392                 }
 393
 394                 BlockVariableMap::iterator j = parent_variables.find(i->first);
 395                 if(j==parent_variables.end())
 396                         parent_variables.insert(*i);
 397                 else
 398                 {
 399                         if(i->second.referenced || !i->second.conditionally_assigned)
 400                                 clear_assignments(j->second, !i->second.referenced);
 401                         j->second.conditionally_assigned = i->second.conditionally_assigned;
 402                         j->second.referenced |= i->second.referenced;
 403                         j->second.assignments.insert(j->second.assignments.end(), i->second.assignments.begin(), i->second.assignments.end());
 404                 }
 405         }
 406         variables.pop_back();
 407 }
 408
 409 void UnusedVariableRemover::visit(Conditional &cond)
 410 {
 411         cond.condition->visit(*this);
 412         variables.push_back(BlockVariableMap());
 413         cond.body.visit(*this);
 414
 415         BlockVariableMap if_variables;
 416         swap(variables.back(), if_variables);
 417         cond.else_body.visit(*this);
 418
 419         BlockVariableMap &else_variables = variables.back();
 420         for(BlockVariableMap::iterator i=else_variables.begin(); i!=else_variables.end(); ++i)
 421         {
 422                 BlockVariableMap::iterator j = if_variables.find(i->first);
 423                 if(j!=if_variables.end())
 424                 {
 425                         i->second.assignments.insert(i->second.assignments.end(), j->second.assignments.begin(), j->second.assignments.end());
 426                         i->second.conditionally_assigned |= j->second.conditionally_assigned;
 427                         if_variables.erase(j);
 428                 }
 429                 else
 430                         i->second.conditionally_assigned = true;
 431         }
 432
 433         for(BlockVariableMap::iterator i=if_variables.begin(); i!=if_variables.end(); ++i)
 434         {
 435                 i->second.conditionally_assigned = true;
 436                 else_variables.insert(*i);
 437         }
 438
 439         merge_down_variables();
 440 }
 441
 442 void UnusedVariableRemover::visit(Iteration &iter)
 443 {
 444         variables.push_back(BlockVariableMap());
 445         TraversingVisitor::visit(iter);
 446
 447         BlockVariableMap &block_variables = variables.back();
 448         for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
 449                 if(!i->second.local && i->second.referenced)
 450                         clear_assignments(i->second, false);
 451
 452         merge_down_variables();
 453 }
 454
 455
 456 bool UnusedFunctionRemover::apply(Stage &stage)
 457 {
 458         stage.content.visit(*this);
 459         NodeRemover().apply(stage, unused_nodes);
 460         return !unused_nodes.empty();
 461 }
 462
 463 void UnusedFunctionRemover::visit(FunctionCall &call)
 464 {
 465         TraversingVisitor::visit(call);
 466
 467         unused_nodes.erase(call.declaration);
 468         if(call.declaration && call.declaration->definition!=call.declaration)
 469                 used_definitions.insert(call.declaration->definition);
 470 }
 471
 472 void UnusedFunctionRemover::visit(FunctionDeclaration &func)
 473 {
 474         TraversingVisitor::visit(func);
 475
 476         if((func.name!="main" || func.body.body.empty()) && !used_definitions.count(&func))
 477                 unused_nodes.insert(&func);
 478 }
 479
 480 } // namespace SL
 481 } // namespace GL
 482 } // namespace Msp