ValueEnumerator.cpp revision 204642
1//===-- ValueEnumerator.cpp - Number values and types for bitcode writer --===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the ValueEnumerator class. 11// 12//===----------------------------------------------------------------------===// 13 14#include "ValueEnumerator.h" 15#include "llvm/Constants.h" 16#include "llvm/DerivedTypes.h" 17#include "llvm/Module.h" 18#include "llvm/TypeSymbolTable.h" 19#include "llvm/ValueSymbolTable.h" 20#include "llvm/Instructions.h" 21#include <algorithm> 22using namespace llvm; 23 24static bool isSingleValueType(const std::pair<const llvm::Type*, 25 unsigned int> &P) { 26 return P.first->isSingleValueType(); 27} 28 29static bool isIntegerValue(const std::pair<const Value*, unsigned> &V) { 30 return V.first->getType()->isIntegerTy(); 31} 32 33static bool CompareByFrequency(const std::pair<const llvm::Type*, 34 unsigned int> &P1, 35 const std::pair<const llvm::Type*, 36 unsigned int> &P2) { 37 return P1.second > P2.second; 38} 39 40/// ValueEnumerator - Enumerate module-level information. 41ValueEnumerator::ValueEnumerator(const Module *M) { 42 // Enumerate the global variables. 43 for (Module::const_global_iterator I = M->global_begin(), 44 E = M->global_end(); I != E; ++I) 45 EnumerateValue(I); 46 47 // Enumerate the functions. 48 for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) { 49 EnumerateValue(I); 50 EnumerateAttributes(cast<Function>(I)->getAttributes()); 51 } 52 53 // Enumerate the aliases. 54 for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end(); 55 I != E; ++I) 56 EnumerateValue(I); 57 58 // Remember what is the cutoff between globalvalue's and other constants. 59 unsigned FirstConstant = Values.size(); 60 61 // Enumerate the global variable initializers. 62 for (Module::const_global_iterator I = M->global_begin(), 63 E = M->global_end(); I != E; ++I) 64 if (I->hasInitializer()) 65 EnumerateValue(I->getInitializer()); 66 67 // Enumerate the aliasees. 68 for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end(); 69 I != E; ++I) 70 EnumerateValue(I->getAliasee()); 71 72 // Enumerate types used by the type symbol table. 73 EnumerateTypeSymbolTable(M->getTypeSymbolTable()); 74 75 // Insert constants and metadata that are named at module level into the slot 76 // pool so that the module symbol table can refer to them... 77 EnumerateValueSymbolTable(M->getValueSymbolTable()); 78 EnumerateMDSymbolTable(M->getMDSymbolTable()); 79 80 SmallVector<std::pair<unsigned, MDNode*>, 8> MDs; 81 82 // Enumerate types used by function bodies and argument lists. 83 for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) { 84 85 for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end(); 86 I != E; ++I) 87 EnumerateType(I->getType()); 88 89 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 90 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E;++I){ 91 for (User::const_op_iterator OI = I->op_begin(), E = I->op_end(); 92 OI != E; ++OI) { 93 if (MDNode *MD = dyn_cast<MDNode>(*OI)) 94 if (MD->isFunctionLocal() && MD->getFunction()) 95 // These will get enumerated during function-incorporation. 96 continue; 97 EnumerateOperandType(*OI); 98 } 99 EnumerateType(I->getType()); 100 if (const CallInst *CI = dyn_cast<CallInst>(I)) 101 EnumerateAttributes(CI->getAttributes()); 102 else if (const InvokeInst *II = dyn_cast<InvokeInst>(I)) 103 EnumerateAttributes(II->getAttributes()); 104 105 // Enumerate metadata attached with this instruction. 106 MDs.clear(); 107 I->getAllMetadata(MDs); 108 for (unsigned i = 0, e = MDs.size(); i != e; ++i) 109 EnumerateMetadata(MDs[i].second); 110 } 111 } 112 113 // Optimize constant ordering. 114 OptimizeConstants(FirstConstant, Values.size()); 115 116 // Sort the type table by frequency so that most commonly used types are early 117 // in the table (have low bit-width). 118 std::stable_sort(Types.begin(), Types.end(), CompareByFrequency); 119 120 // Partition the Type ID's so that the single-value types occur before the 121 // aggregate types. This allows the aggregate types to be dropped from the 122 // type table after parsing the global variable initializers. 123 std::partition(Types.begin(), Types.end(), isSingleValueType); 124 125 // Now that we rearranged the type table, rebuild TypeMap. 126 for (unsigned i = 0, e = Types.size(); i != e; ++i) 127 TypeMap[Types[i].first] = i+1; 128} 129 130unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const { 131 InstructionMapType::const_iterator I = InstructionMap.find(Inst); 132 assert (I != InstructionMap.end() && "Instruction is not mapped!"); 133 return I->second; 134} 135 136void ValueEnumerator::setInstructionID(const Instruction *I) { 137 InstructionMap[I] = InstructionCount++; 138} 139 140unsigned ValueEnumerator::getValueID(const Value *V) const { 141 if (isa<MDNode>(V) || isa<MDString>(V)) { 142 ValueMapType::const_iterator I = MDValueMap.find(V); 143 assert(I != MDValueMap.end() && "Value not in slotcalculator!"); 144 return I->second-1; 145 } 146 147 ValueMapType::const_iterator I = ValueMap.find(V); 148 assert(I != ValueMap.end() && "Value not in slotcalculator!"); 149 return I->second-1; 150} 151 152// Optimize constant ordering. 153namespace { 154 struct CstSortPredicate { 155 ValueEnumerator &VE; 156 explicit CstSortPredicate(ValueEnumerator &ve) : VE(ve) {} 157 bool operator()(const std::pair<const Value*, unsigned> &LHS, 158 const std::pair<const Value*, unsigned> &RHS) { 159 // Sort by plane. 160 if (LHS.first->getType() != RHS.first->getType()) 161 return VE.getTypeID(LHS.first->getType()) < 162 VE.getTypeID(RHS.first->getType()); 163 // Then by frequency. 164 return LHS.second > RHS.second; 165 } 166 }; 167} 168 169/// OptimizeConstants - Reorder constant pool for denser encoding. 170void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) { 171 if (CstStart == CstEnd || CstStart+1 == CstEnd) return; 172 173 CstSortPredicate P(*this); 174 std::stable_sort(Values.begin()+CstStart, Values.begin()+CstEnd, P); 175 176 // Ensure that integer constants are at the start of the constant pool. This 177 // is important so that GEP structure indices come before gep constant exprs. 178 std::partition(Values.begin()+CstStart, Values.begin()+CstEnd, 179 isIntegerValue); 180 181 // Rebuild the modified portion of ValueMap. 182 for (; CstStart != CstEnd; ++CstStart) 183 ValueMap[Values[CstStart].first] = CstStart+1; 184} 185 186 187/// EnumerateTypeSymbolTable - Insert all of the types in the specified symbol 188/// table. 189void ValueEnumerator::EnumerateTypeSymbolTable(const TypeSymbolTable &TST) { 190 for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); 191 TI != TE; ++TI) 192 EnumerateType(TI->second); 193} 194 195/// EnumerateValueSymbolTable - Insert all of the values in the specified symbol 196/// table into the values table. 197void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) { 198 for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end(); 199 VI != VE; ++VI) 200 EnumerateValue(VI->getValue()); 201} 202 203/// EnumerateMDSymbolTable - Insert all of the values in the specified metadata 204/// table. 205void ValueEnumerator::EnumerateMDSymbolTable(const MDSymbolTable &MST) { 206 for (MDSymbolTable::const_iterator MI = MST.begin(), ME = MST.end(); 207 MI != ME; ++MI) 208 EnumerateValue(MI->getValue()); 209} 210 211void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) { 212 // Check to see if it's already in! 213 unsigned &MDValueID = MDValueMap[MD]; 214 if (MDValueID) { 215 // Increment use count. 216 MDValues[MDValueID-1].second++; 217 return; 218 } 219 220 // Enumerate the type of this value. 221 EnumerateType(MD->getType()); 222 223 for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) 224 if (MDNode *E = MD->getOperand(i)) 225 EnumerateValue(E); 226 MDValues.push_back(std::make_pair(MD, 1U)); 227 MDValueMap[MD] = Values.size(); 228} 229 230void ValueEnumerator::EnumerateMetadata(const Value *MD) { 231 assert((isa<MDNode>(MD) || isa<MDString>(MD)) && "Invalid metadata kind"); 232 // Check to see if it's already in! 233 unsigned &MDValueID = MDValueMap[MD]; 234 if (MDValueID) { 235 // Increment use count. 236 MDValues[MDValueID-1].second++; 237 return; 238 } 239 240 // Enumerate the type of this value. 241 EnumerateType(MD->getType()); 242 243 if (const MDNode *N = dyn_cast<MDNode>(MD)) { 244 MDValues.push_back(std::make_pair(MD, 1U)); 245 MDValueMap[MD] = MDValues.size(); 246 MDValueID = MDValues.size(); 247 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { 248 if (Value *V = N->getOperand(i)) 249 EnumerateValue(V); 250 else 251 EnumerateType(Type::getVoidTy(MD->getContext())); 252 } 253 return; 254 } 255 256 // Add the value. 257 assert(isa<MDString>(MD) && "Unknown metadata kind"); 258 MDValues.push_back(std::make_pair(MD, 1U)); 259 MDValueID = MDValues.size(); 260} 261 262void ValueEnumerator::EnumerateValue(const Value *V) { 263 assert(!V->getType()->isVoidTy() && "Can't insert void values!"); 264 if (isa<MDNode>(V) || isa<MDString>(V)) 265 return EnumerateMetadata(V); 266 else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(V)) 267 return EnumerateNamedMDNode(NMD); 268 269 // Check to see if it's already in! 270 unsigned &ValueID = ValueMap[V]; 271 if (ValueID) { 272 // Increment use count. 273 Values[ValueID-1].second++; 274 return; 275 } 276 277 // Enumerate the type of this value. 278 EnumerateType(V->getType()); 279 280 if (const Constant *C = dyn_cast<Constant>(V)) { 281 if (isa<GlobalValue>(C)) { 282 // Initializers for globals are handled explicitly elsewhere. 283 } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) { 284 // Do not enumerate the initializers for an array of simple characters. 285 // The initializers just polute the value table, and we emit the strings 286 // specially. 287 } else if (C->getNumOperands()) { 288 // If a constant has operands, enumerate them. This makes sure that if a 289 // constant has uses (for example an array of const ints), that they are 290 // inserted also. 291 292 // We prefer to enumerate them with values before we enumerate the user 293 // itself. This makes it more likely that we can avoid forward references 294 // in the reader. We know that there can be no cycles in the constants 295 // graph that don't go through a global variable. 296 for (User::const_op_iterator I = C->op_begin(), E = C->op_end(); 297 I != E; ++I) 298 if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress. 299 EnumerateValue(*I); 300 301 // Finally, add the value. Doing this could make the ValueID reference be 302 // dangling, don't reuse it. 303 Values.push_back(std::make_pair(V, 1U)); 304 ValueMap[V] = Values.size(); 305 return; 306 } 307 } 308 309 // Add the value. 310 Values.push_back(std::make_pair(V, 1U)); 311 ValueID = Values.size(); 312} 313 314 315void ValueEnumerator::EnumerateType(const Type *Ty) { 316 unsigned &TypeID = TypeMap[Ty]; 317 318 if (TypeID) { 319 // If we've already seen this type, just increase its occurrence count. 320 Types[TypeID-1].second++; 321 return; 322 } 323 324 // First time we saw this type, add it. 325 Types.push_back(std::make_pair(Ty, 1U)); 326 TypeID = Types.size(); 327 328 // Enumerate subtypes. 329 for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end(); 330 I != E; ++I) 331 EnumerateType(*I); 332} 333 334// Enumerate the types for the specified value. If the value is a constant, 335// walk through it, enumerating the types of the constant. 336void ValueEnumerator::EnumerateOperandType(const Value *V) { 337 EnumerateType(V->getType()); 338 339 if (const Constant *C = dyn_cast<Constant>(V)) { 340 // If this constant is already enumerated, ignore it, we know its type must 341 // be enumerated. 342 if (ValueMap.count(V)) return; 343 344 // This constant may have operands, make sure to enumerate the types in 345 // them. 346 for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) { 347 const User *Op = C->getOperand(i); 348 349 // Don't enumerate basic blocks here, this happens as operands to 350 // blockaddress. 351 if (isa<BasicBlock>(Op)) continue; 352 353 EnumerateOperandType(cast<Constant>(Op)); 354 } 355 356 if (const MDNode *N = dyn_cast<MDNode>(V)) { 357 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) 358 if (Value *Elem = N->getOperand(i)) 359 EnumerateOperandType(Elem); 360 } 361 } else if (isa<MDString>(V) || isa<MDNode>(V)) 362 EnumerateValue(V); 363} 364 365void ValueEnumerator::EnumerateAttributes(const AttrListPtr &PAL) { 366 if (PAL.isEmpty()) return; // null is always 0. 367 // Do a lookup. 368 unsigned &Entry = AttributeMap[PAL.getRawPointer()]; 369 if (Entry == 0) { 370 // Never saw this before, add it. 371 Attributes.push_back(PAL); 372 Entry = Attributes.size(); 373 } 374} 375 376 377void ValueEnumerator::incorporateFunction(const Function &F) { 378 InstructionCount = 0; 379 NumModuleValues = Values.size(); 380 381 // Adding function arguments to the value table. 382 for(Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); 383 I != E; ++I) 384 EnumerateValue(I); 385 386 FirstFuncConstantID = Values.size(); 387 388 // Add all function-level constants to the value table. 389 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { 390 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) 391 for (User::const_op_iterator OI = I->op_begin(), E = I->op_end(); 392 OI != E; ++OI) { 393 if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) || 394 isa<InlineAsm>(*OI)) 395 EnumerateValue(*OI); 396 } 397 BasicBlocks.push_back(BB); 398 ValueMap[BB] = BasicBlocks.size(); 399 } 400 401 // Optimize the constant layout. 402 OptimizeConstants(FirstFuncConstantID, Values.size()); 403 404 // Add the function's parameter attributes so they are available for use in 405 // the function's instruction. 406 EnumerateAttributes(F.getAttributes()); 407 408 FirstInstID = Values.size(); 409 410 SmallVector<MDNode *, 8> FunctionLocalMDs; 411 // Add all of the instructions. 412 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { 413 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) { 414 for (User::const_op_iterator OI = I->op_begin(), E = I->op_end(); 415 OI != E; ++OI) { 416 if (MDNode *MD = dyn_cast<MDNode>(*OI)) 417 if (MD->isFunctionLocal() && MD->getFunction()) 418 // Enumerate metadata after the instructions they might refer to. 419 FunctionLocalMDs.push_back(MD); 420 } 421 if (!I->getType()->isVoidTy()) 422 EnumerateValue(I); 423 } 424 } 425 426 // Add all of the function-local metadata. 427 for (unsigned i = 0, e = FunctionLocalMDs.size(); i != e; ++i) 428 EnumerateOperandType(FunctionLocalMDs[i]); 429} 430 431void ValueEnumerator::purgeFunction() { 432 /// Remove purged values from the ValueMap. 433 for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i) 434 ValueMap.erase(Values[i].first); 435 for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i) 436 ValueMap.erase(BasicBlocks[i]); 437 438 Values.resize(NumModuleValues); 439 BasicBlocks.clear(); 440} 441 442static void IncorporateFunctionInfoGlobalBBIDs(const Function *F, 443 DenseMap<const BasicBlock*, unsigned> &IDMap) { 444 unsigned Counter = 0; 445 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 446 IDMap[BB] = ++Counter; 447} 448 449/// getGlobalBasicBlockID - This returns the function-specific ID for the 450/// specified basic block. This is relatively expensive information, so it 451/// should only be used by rare constructs such as address-of-label. 452unsigned ValueEnumerator::getGlobalBasicBlockID(const BasicBlock *BB) const { 453 unsigned &Idx = GlobalBasicBlockIDs[BB]; 454 if (Idx != 0) 455 return Idx-1; 456 457 IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs); 458 return getGlobalBasicBlockID(BB); 459} 460 461