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