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