lib/VMCore/ConstantsContext.h

   1 //===-- ConstantsContext.h - Constants-related Context Interals -----------===//
   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 defines various helper methods and classes used by
  11 // LLVMContextImpl for creating and managing constants.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_CONSTANTSCONTEXT_H
  16 #define LLVM_CONSTANTSCONTEXT_H
  17
  18 #include "llvm/InlineAsm.h"
  19 #include "llvm/Instructions.h"
  20 #include "llvm/Operator.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/ErrorHandling.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include <map>
  25
  26 namespace llvm {
  27 template<class ValType>
  28 struct ConstantTraits;
  29
  30 /// UnaryConstantExpr - This class is private to Constants.cpp, and is used
  31 /// behind the scenes to implement unary constant exprs.
  32 class UnaryConstantExpr : public ConstantExpr {
  33   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
  34 public:
  35   // allocate space for exactly one operand
  36   void *operator new(size_t s) {
  37     return User::operator new(s, 1);
  38   }
  39   UnaryConstantExpr(unsigned Opcode, Constant *C, const Type *Ty)
  40     : ConstantExpr(Ty, Opcode, &Op<0>(), 1) {
  41     Op<0>() = C;
  42   }
  43   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
  44 };
  45
  46 /// BinaryConstantExpr - This class is private to Constants.cpp, and is used
  47 /// behind the scenes to implement binary constant exprs.
  48 class BinaryConstantExpr : public ConstantExpr {
  49   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
  50 public:
  51   // allocate space for exactly two operands
  52   void *operator new(size_t s) {
  53     return User::operator new(s, 2);
  54   }
  55   BinaryConstantExpr(unsigned Opcode, Constant *C1, Constant *C2,
  56                      unsigned Flags)
  57     : ConstantExpr(C1->getType(), Opcode, &Op<0>(), 2) {
  58     Op<0>() = C1;
  59     Op<1>() = C2;
  60     SubclassOptionalData = Flags;
  61   }
  62   /// Transparently provide more efficient getOperand methods.
  63   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
  64 };
  65
  66 /// SelectConstantExpr - This class is private to Constants.cpp, and is used
  67 /// behind the scenes to implement select constant exprs.
  68 class SelectConstantExpr : public ConstantExpr {
  69   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
  70 public:
  71   // allocate space for exactly three operands
  72   void *operator new(size_t s) {
  73     return User::operator new(s, 3);
  74   }
  75   SelectConstantExpr(Constant *C1, Constant *C2, Constant *C3)
  76     : ConstantExpr(C2->getType(), Instruction::Select, &Op<0>(), 3) {
  77     Op<0>() = C1;
  78     Op<1>() = C2;
  79     Op<2>() = C3;
  80   }
  81   /// Transparently provide more efficient getOperand methods.
  82   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
  83 };
  84
  85 /// ExtractElementConstantExpr - This class is private to
  86 /// Constants.cpp, and is used behind the scenes to implement
  87 /// extractelement constant exprs.
  88 class ExtractElementConstantExpr : public ConstantExpr {
  89   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
  90 public:
  91   // allocate space for exactly two operands
  92   void *operator new(size_t s) {
  93     return User::operator new(s, 2);
  94   }
  95   ExtractElementConstantExpr(Constant *C1, Constant *C2)
  96     : ConstantExpr(cast<VectorType>(C1->getType())->getElementType(),
  97                    Instruction::ExtractElement, &Op<0>(), 2) {
  98     Op<0>() = C1;
  99     Op<1>() = C2;
 100   }
 101   /// Transparently provide more efficient getOperand methods.
 102   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 103 };
 104
 105 /// InsertElementConstantExpr - This class is private to
 106 /// Constants.cpp, and is used behind the scenes to implement
 107 /// insertelement constant exprs.
 108 class InsertElementConstantExpr : public ConstantExpr {
 109   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
 110 public:
 111   // allocate space for exactly three operands
 112   void *operator new(size_t s) {
 113     return User::operator new(s, 3);
 114   }
 115   InsertElementConstantExpr(Constant *C1, Constant *C2, Constant *C3)
 116     : ConstantExpr(C1->getType(), Instruction::InsertElement,
 117                    &Op<0>(), 3) {
 118     Op<0>() = C1;
 119     Op<1>() = C2;
 120     Op<2>() = C3;
 121   }
 122   /// Transparently provide more efficient getOperand methods.
 123   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 124 };
 125
 126 /// ShuffleVectorConstantExpr - This class is private to
 127 /// Constants.cpp, and is used behind the scenes to implement
 128 /// shufflevector constant exprs.
 129 class ShuffleVectorConstantExpr : public ConstantExpr {
 130   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
 131 public:
 132   // allocate space for exactly three operands
 133   void *operator new(size_t s) {
 134     return User::operator new(s, 3);
 135   }
 136   ShuffleVectorConstantExpr(Constant *C1, Constant *C2, Constant *C3)
 137   : ConstantExpr(VectorType::get(
 138                    cast<VectorType>(C1->getType())->getElementType(),
 139                    cast<VectorType>(C3->getType())->getNumElements()),
 140                  Instruction::ShuffleVector,
 141                  &Op<0>(), 3) {
 142     Op<0>() = C1;
 143     Op<1>() = C2;
 144     Op<2>() = C3;
 145   }
 146   /// Transparently provide more efficient getOperand methods.
 147   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 148 };
 149
 150 /// ExtractValueConstantExpr - This class is private to
 151 /// Constants.cpp, and is used behind the scenes to implement
 152 /// extractvalue constant exprs.
 153 class ExtractValueConstantExpr : public ConstantExpr {
 154   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
 155 public:
 156   // allocate space for exactly one operand
 157   void *operator new(size_t s) {
 158     return User::operator new(s, 1);
 159   }
 160   ExtractValueConstantExpr(Constant *Agg,
 161                            const SmallVector<unsigned, 4> &IdxList,
 162                            const Type *DestTy)
 163     : ConstantExpr(DestTy, Instruction::ExtractValue, &Op<0>(), 1),
 164       Indices(IdxList) {
 165     Op<0>() = Agg;
 166   }
 167
 168   /// Indices - These identify which value to extract.
 169   const SmallVector<unsigned, 4> Indices;
 170
 171   /// Transparently provide more efficient getOperand methods.
 172   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 173 };
 174
 175 /// InsertValueConstantExpr - This class is private to
 176 /// Constants.cpp, and is used behind the scenes to implement
 177 /// insertvalue constant exprs.
 178 class InsertValueConstantExpr : public ConstantExpr {
 179   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
 180 public:
 181   // allocate space for exactly one operand
 182   void *operator new(size_t s) {
 183     return User::operator new(s, 2);
 184   }
 185   InsertValueConstantExpr(Constant *Agg, Constant *Val,
 186                           const SmallVector<unsigned, 4> &IdxList,
 187                           const Type *DestTy)
 188     : ConstantExpr(DestTy, Instruction::InsertValue, &Op<0>(), 2),
 189       Indices(IdxList) {
 190     Op<0>() = Agg;
 191     Op<1>() = Val;
 192   }
 193
 194   /// Indices - These identify the position for the insertion.
 195   const SmallVector<unsigned, 4> Indices;
 196
 197   /// Transparently provide more efficient getOperand methods.
 198   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 199 };
 200
 201
 202 /// GetElementPtrConstantExpr - This class is private to Constants.cpp, and is
 203 /// used behind the scenes to implement getelementpr constant exprs.
 204 class GetElementPtrConstantExpr : public ConstantExpr {
 205   GetElementPtrConstantExpr(Constant *C, const std::vector<Constant*> &IdxList,
 206                             const Type *DestTy);
 207 public:
 208   static GetElementPtrConstantExpr *Create(Constant *C,
 209                                            const std::vector<Constant*>&IdxList,
 210                                            const Type *DestTy,
 211                                            unsigned Flags) {
 212     GetElementPtrConstantExpr *Result =
 213       new(IdxList.size() + 1) GetElementPtrConstantExpr(C, IdxList, DestTy);
 214     Result->SubclassOptionalData = Flags;
 215     return Result;
 216   }
 217   /// Transparently provide more efficient getOperand methods.
 218   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 219 };
 220
 221 // CompareConstantExpr - This class is private to Constants.cpp, and is used
 222 // behind the scenes to implement ICmp and FCmp constant expressions. This is
 223 // needed in order to store the predicate value for these instructions.
 224 struct CompareConstantExpr : public ConstantExpr {
 225   void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
 226   // allocate space for exactly two operands
 227   void *operator new(size_t s) {
 228     return User::operator new(s, 2);
 229   }
 230   unsigned short predicate;
 231   CompareConstantExpr(const Type *ty, Instruction::OtherOps opc,
 232                       unsigned short pred,  Constant* LHS, Constant* RHS)
 233     : ConstantExpr(ty, opc, &Op<0>(), 2), predicate(pred) {
 234     Op<0>() = LHS;
 235     Op<1>() = RHS;
 236   }
 237   /// Transparently provide more efficient getOperand methods.
 238   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 239 };
 240
 241 template <>
 242 struct OperandTraits<UnaryConstantExpr> : public FixedNumOperandTraits<1> {
 243 };
 244 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(UnaryConstantExpr, Value)
 245
 246 template <>
 247 struct OperandTraits<BinaryConstantExpr> : public FixedNumOperandTraits<2> {
 248 };
 249 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BinaryConstantExpr, Value)
 250
 251 template <>
 252 struct OperandTraits<SelectConstantExpr> : public FixedNumOperandTraits<3> {
 253 };
 254 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(SelectConstantExpr, Value)
 255
 256 template <>
 257 struct OperandTraits<ExtractElementConstantExpr> : public FixedNumOperandTraits<2> {
 258 };
 259 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractElementConstantExpr, Value)
 260
 261 template <>
 262 struct OperandTraits<InsertElementConstantExpr> : public FixedNumOperandTraits<3> {
 263 };
 264 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertElementConstantExpr, Value)
 265
 266 template <>
 267 struct OperandTraits<ShuffleVectorConstantExpr> : public FixedNumOperandTraits<3> {
 268 };
 269 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ShuffleVectorConstantExpr, Value)
 270
 271 template <>
 272 struct OperandTraits<ExtractValueConstantExpr> : public FixedNumOperandTraits<1> {
 273 };
 274 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractValueConstantExpr, Value)
 275
 276 template <>
 277 struct OperandTraits<InsertValueConstantExpr> : public FixedNumOperandTraits<2> {
 278 };
 279 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertValueConstantExpr, Value)
 280
 281 template <>
 282 struct OperandTraits<GetElementPtrConstantExpr> : public VariadicOperandTraits<1> {
 283 };
 284
 285 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GetElementPtrConstantExpr, Value)
 286
 287
 288 template <>
 289 struct OperandTraits<CompareConstantExpr> : public FixedNumOperandTraits<2> {
 290 };
 291 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CompareConstantExpr, Value)
 292
 293 struct ExprMapKeyType {
 294   typedef SmallVector<unsigned, 4> IndexList;
 295
 296   ExprMapKeyType(unsigned opc,
 297       const std::vector<Constant*> &ops,
 298       unsigned short flags = 0,
 299       unsigned short optionalflags = 0,
 300       const IndexList &inds = IndexList())
 301         : opcode(opc), subclassoptionaldata(optionalflags), subclassdata(flags),
 302         operands(ops), indices(inds) {}
 303   uint8_t opcode;
 304   uint8_t subclassoptionaldata;
 305   uint16_t subclassdata;
 306   std::vector<Constant*> operands;
 307   IndexList indices;
 308   bool operator==(const ExprMapKeyType& that) const {
 309     return this->opcode == that.opcode &&
 310            this->subclassdata == that.subclassdata &&
 311            this->subclassoptionaldata == that.subclassoptionaldata &&
 312            this->operands == that.operands &&
 313            this->indices == that.indices;
 314   }
 315   bool operator<(const ExprMapKeyType & that) const {
 316     if (this->opcode != that.opcode) return this->opcode < that.opcode;
 317     if (this->operands != that.operands) return this->operands < that.operands;
 318     if (this->subclassdata != that.subclassdata)
 319       return this->subclassdata < that.subclassdata;
 320     if (this->subclassoptionaldata != that.subclassoptionaldata)
 321       return this->subclassoptionaldata < that.subclassoptionaldata;
 322     if (this->indices != that.indices) return this->indices < that.indices;
 323     return false;
 324   }
 325
 326   bool operator!=(const ExprMapKeyType& that) const {
 327     return !(*this == that);
 328   }
 329 };
 330
 331 struct InlineAsmKeyType {
 332   InlineAsmKeyType(StringRef AsmString,
 333                    StringRef Constraints, bool hasSideEffects,
 334                    bool isAlignStack)
 335     : asm_string(AsmString), constraints(Constraints),
 336       has_side_effects(hasSideEffects), is_align_stack(isAlignStack) {}
 337   std::string asm_string;
 338   std::string constraints;
 339   bool has_side_effects;
 340   bool is_align_stack;
 341   bool operator==(const InlineAsmKeyType& that) const {
 342     return this->asm_string == that.asm_string &&
 343            this->constraints == that.constraints &&
 344            this->has_side_effects == that.has_side_effects &&
 345            this->is_align_stack == that.is_align_stack;
 346   }
 347   bool operator<(const InlineAsmKeyType& that) const {
 348     if (this->asm_string != that.asm_string)
 349       return this->asm_string < that.asm_string;
 350     if (this->constraints != that.constraints)
 351       return this->constraints < that.constraints;
 352     if (this->has_side_effects != that.has_side_effects)
 353       return this->has_side_effects < that.has_side_effects;
 354     if (this->is_align_stack != that.is_align_stack)
 355       return this->is_align_stack < that.is_align_stack;
 356     return false;
 357   }
 358
 359   bool operator!=(const InlineAsmKeyType& that) const {
 360     return !(*this == that);
 361   }
 362 };
 363
 364 // The number of operands for each ConstantCreator::create method is
 365 // determined by the ConstantTraits template.
 366 // ConstantCreator - A class that is used to create constants by
 367 // ConstantUniqueMap*.  This class should be partially specialized if there is
 368 // something strange that needs to be done to interface to the ctor for the
 369 // constant.
 370 //
 371 template<typename T, typename Alloc>
 372 struct ConstantTraits< std::vector<T, Alloc> > {
 373   static unsigned uses(const std::vector<T, Alloc>& v) {
 374     return v.size();
 375   }
 376 };
 377
 378 template<>
 379 struct ConstantTraits<Constant *> {
 380   static unsigned uses(Constant * const & v) {
 381     return 1;
 382   }
 383 };
 384
 385 template<class ConstantClass, class TypeClass, class ValType>
 386 struct ConstantCreator {
 387   static ConstantClass *create(const TypeClass *Ty, const ValType &V) {
 388     return new(ConstantTraits<ValType>::uses(V)) ConstantClass(Ty, V);
 389   }
 390 };
 391
 392 template<class ConstantClass>
 393 struct ConstantKeyData {
 394   typedef void ValType;
 395   static ValType getValType(ConstantClass *C) {
 396     llvm_unreachable("Unknown Constant type!");
 397   }
 398 };
 399
 400 template<>
 401 struct ConstantCreator<ConstantExpr, Type, ExprMapKeyType> {
 402   static ConstantExpr *create(const Type *Ty, const ExprMapKeyType &V,
 403       unsigned short pred = 0) {
 404     if (Instruction::isCast(V.opcode))
 405       return new UnaryConstantExpr(V.opcode, V.operands[0], Ty);
 406     if ((V.opcode >= Instruction::BinaryOpsBegin &&
 407          V.opcode < Instruction::BinaryOpsEnd))
 408       return new BinaryConstantExpr(V.opcode, V.operands[0], V.operands[1],
 409                                     V.subclassoptionaldata);
 410     if (V.opcode == Instruction::Select)
 411       return new SelectConstantExpr(V.operands[0], V.operands[1],
 412                                     V.operands[2]);
 413     if (V.opcode == Instruction::ExtractElement)
 414       return new ExtractElementConstantExpr(V.operands[0], V.operands[1]);
 415     if (V.opcode == Instruction::InsertElement)
 416       return new InsertElementConstantExpr(V.operands[0], V.operands[1],
 417                                            V.operands[2]);
 418     if (V.opcode == Instruction::ShuffleVector)
 419       return new ShuffleVectorConstantExpr(V.operands[0], V.operands[1],
 420                                            V.operands[2]);
 421     if (V.opcode == Instruction::InsertValue)
 422       return new InsertValueConstantExpr(V.operands[0], V.operands[1],
 423                                          V.indices, Ty);
 424     if (V.opcode == Instruction::ExtractValue)
 425       return new ExtractValueConstantExpr(V.operands[0], V.indices, Ty);
 426     if (V.opcode == Instruction::GetElementPtr) {
 427       std::vector<Constant*> IdxList(V.operands.begin()+1, V.operands.end());
 428       return GetElementPtrConstantExpr::Create(V.operands[0], IdxList, Ty,
 429                                                V.subclassoptionaldata);
 430     }
 431
 432     // The compare instructions are weird. We have to encode the predicate
 433     // value and it is combined with the instruction opcode by multiplying
 434     // the opcode by one hundred. We must decode this to get the predicate.
 435     if (V.opcode == Instruction::ICmp)
 436       return new CompareConstantExpr(Ty, Instruction::ICmp, V.subclassdata,
 437                                      V.operands[0], V.operands[1]);
 438     if (V.opcode == Instruction::FCmp)
 439       return new CompareConstantExpr(Ty, Instruction::FCmp, V.subclassdata,
 440                                      V.operands[0], V.operands[1]);
 441     llvm_unreachable("Invalid ConstantExpr!");
 442     return 0;
 443   }
 444 };
 445
 446 template<>
 447 struct ConstantKeyData<ConstantExpr> {
 448   typedef ExprMapKeyType ValType;
 449   static ValType getValType(ConstantExpr *CE) {
 450     std::vector<Constant*> Operands;
 451     Operands.reserve(CE->getNumOperands());
 452     for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
 453       Operands.push_back(cast<Constant>(CE->getOperand(i)));
 454     return ExprMapKeyType(CE->getOpcode(), Operands,
 455         CE->isCompare() ? CE->getPredicate() : 0,
 456         CE->getRawSubclassOptionalData(),
 457         CE->hasIndices() ?
 458           CE->getIndices() : SmallVector<unsigned, 4>());
 459   }
 460 };
 461
 462 // ConstantAggregateZero does not take extra "value" argument...
 463 template<class ValType>
 464 struct ConstantCreator<ConstantAggregateZero, Type, ValType> {
 465   static ConstantAggregateZero *create(const Type *Ty, const ValType &V){
 466     return new ConstantAggregateZero(Ty);
 467   }
 468 };
 469
 470 template<>
 471 struct ConstantKeyData<ConstantVector> {
 472   typedef std::vector<Constant*> ValType;
 473   static ValType getValType(ConstantVector *CP) {
 474     std::vector<Constant*> Elements;
 475     Elements.reserve(CP->getNumOperands());
 476     for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
 477       Elements.push_back(CP->getOperand(i));
 478     return Elements;
 479   }
 480 };
 481
 482 template<>
 483 struct ConstantKeyData<ConstantAggregateZero> {
 484   typedef char ValType;
 485   static ValType getValType(ConstantAggregateZero *C) {
 486     return 0;
 487   }
 488 };
 489
 490 template<>
 491 struct ConstantKeyData<ConstantArray> {
 492   typedef std::vector<Constant*> ValType;
 493   static ValType getValType(ConstantArray *CA) {
 494     std::vector<Constant*> Elements;
 495     Elements.reserve(CA->getNumOperands());
 496     for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
 497       Elements.push_back(cast<Constant>(CA->getOperand(i)));
 498     return Elements;
 499   }
 500 };
 501
 502 template<>
 503 struct ConstantKeyData<ConstantStruct> {
 504   typedef std::vector<Constant*> ValType;
 505   static ValType getValType(ConstantStruct *CS) {
 506     std::vector<Constant*> Elements;
 507     Elements.reserve(CS->getNumOperands());
 508     for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i)
 509       Elements.push_back(cast<Constant>(CS->getOperand(i)));
 510     return Elements;
 511   }
 512 };
 513
 514 // ConstantPointerNull does not take extra "value" argument...
 515 template<class ValType>
 516 struct ConstantCreator<ConstantPointerNull, PointerType, ValType> {
 517   static ConstantPointerNull *create(const PointerType *Ty, const ValType &V){
 518     return new ConstantPointerNull(Ty);
 519   }
 520 };
 521
 522 template<>
 523 struct ConstantKeyData<ConstantPointerNull> {
 524   typedef char ValType;
 525   static ValType getValType(ConstantPointerNull *C) {
 526     return 0;
 527   }
 528 };
 529
 530 // UndefValue does not take extra "value" argument...
 531 template<class ValType>
 532 struct ConstantCreator<UndefValue, Type, ValType> {
 533   static UndefValue *create(const Type *Ty, const ValType &V) {
 534     return new UndefValue(Ty);
 535   }
 536 };
 537
 538 template<>
 539 struct ConstantKeyData<UndefValue> {
 540   typedef char ValType;
 541   static ValType getValType(UndefValue *C) {
 542     return 0;
 543   }
 544 };
 545
 546 template<>
 547 struct ConstantCreator<InlineAsm, PointerType, InlineAsmKeyType> {
 548   static InlineAsm *create(const PointerType *Ty, const InlineAsmKeyType &Key) {
 549     return new InlineAsm(Ty, Key.asm_string, Key.constraints,
 550                          Key.has_side_effects, Key.is_align_stack);
 551   }
 552 };
 553
 554 template<>
 555 struct ConstantKeyData<InlineAsm> {
 556   typedef InlineAsmKeyType ValType;
 557   static ValType getValType(InlineAsm *Asm) {
 558     return InlineAsmKeyType(Asm->getAsmString(), Asm->getConstraintString(),
 559                             Asm->hasSideEffects(), Asm->isAlignStack());
 560   }
 561 };
 562
 563 template<class ValType, class TypeClass, class ConstantClass,
 564          bool HasLargeKey = false /*true for arrays and structs*/ >
 565 class ConstantUniqueMap : public AbstractTypeUser {
 566 public:
 567   typedef std::pair<const TypeClass*, ValType> MapKey;
 568   typedef std::map<MapKey, ConstantClass *> MapTy;
 569   typedef std::map<ConstantClass *, typename MapTy::iterator> InverseMapTy;
 570   typedef std::map<const DerivedType*, typename MapTy::iterator>
 571     AbstractTypeMapTy;
 572 private:
 573   /// Map - This is the main map from the element descriptor to the Constants.
 574   /// This is the primary way we avoid creating two of the same shape
 575   /// constant.
 576   MapTy Map;
 577
 578   /// InverseMap - If "HasLargeKey" is true, this contains an inverse mapping
 579   /// from the constants to their element in Map.  This is important for
 580   /// removal of constants from the array, which would otherwise have to scan
 581   /// through the map with very large keys.
 582   InverseMapTy InverseMap;
 583
 584   /// AbstractTypeMap - Map for abstract type constants.
 585   ///
 586   AbstractTypeMapTy AbstractTypeMap;
 587
 588 public:
 589   typename MapTy::iterator map_begin() { return Map.begin(); }
 590   typename MapTy::iterator map_end() { return Map.end(); }
 591
 592   void freeConstants() {
 593     for (typename MapTy::iterator I=Map.begin(), E=Map.end();
 594          I != E; ++I) {
 595       // Asserts that use_empty().
 596       delete I->second;
 597     }
 598   }
 599
 600   /// InsertOrGetItem - Return an iterator for the specified element.
 601   /// If the element exists in the map, the returned iterator points to the
 602   /// entry and Exists=true.  If not, the iterator points to the newly
 603   /// inserted entry and returns Exists=false.  Newly inserted entries have
 604   /// I->second == 0, and should be filled in.
 605   typename MapTy::iterator InsertOrGetItem(std::pair<MapKey, ConstantClass *>
 606                                  &InsertVal,
 607                                  bool &Exists) {
 608     std::pair<typename MapTy::iterator, bool> IP = Map.insert(InsertVal);
 609     Exists = !IP.second;
 610     return IP.first;
 611   }
 612
 613 private:
 614   typename MapTy::iterator FindExistingElement(ConstantClass *CP) {
 615     if (HasLargeKey) {
 616       typename InverseMapTy::iterator IMI = InverseMap.find(CP);
 617       assert(IMI != InverseMap.end() && IMI->second != Map.end() &&
 618              IMI->second->second == CP &&
 619              "InverseMap corrupt!");
 620       return IMI->second;
 621     }
 622
 623     typename MapTy::iterator I =
 624       Map.find(MapKey(static_cast<const TypeClass*>(CP->getRawType()),
 625                       ConstantKeyData<ConstantClass>::getValType(CP)));
 626     if (I == Map.end() || I->second != CP) {
 627       // FIXME: This should not use a linear scan.  If this gets to be a
 628       // performance problem, someone should look at this.
 629       for (I = Map.begin(); I != Map.end() && I->second != CP; ++I)
 630         /* empty */;
 631     }
 632     return I;
 633   }
 634
 635   void AddAbstractTypeUser(const Type *Ty, typename MapTy::iterator I) {
 636     // If the type of the constant is abstract, make sure that an entry
 637     // exists for it in the AbstractTypeMap.
 638     if (Ty->isAbstract()) {
 639       const DerivedType *DTy = static_cast<const DerivedType *>(Ty);
 640       typename AbstractTypeMapTy::iterator TI = AbstractTypeMap.find(DTy);
 641
 642       if (TI == AbstractTypeMap.end()) {
 643         // Add ourselves to the ATU list of the type.
 644         cast<DerivedType>(DTy)->addAbstractTypeUser(this);
 645
 646         AbstractTypeMap.insert(TI, std::make_pair(DTy, I));
 647       }
 648     }
 649   }
 650
 651   ConstantClass* Create(const TypeClass *Ty, const ValType &V,
 652                         typename MapTy::iterator I) {
 653     ConstantClass* Result =
 654       ConstantCreator<ConstantClass,TypeClass,ValType>::create(Ty, V);
 655
 656     assert(Result->getType() == Ty && "Type specified is not correct!");
 657     I = Map.insert(I, std::make_pair(MapKey(Ty, V), Result));
 658
 659     if (HasLargeKey)  // Remember the reverse mapping if needed.
 660       InverseMap.insert(std::make_pair(Result, I));
 661
 662     AddAbstractTypeUser(Ty, I);
 663
 664     return Result;
 665   }
 666 public:
 667
 668   /// getOrCreate - Return the specified constant from the map, creating it if
 669   /// necessary.
 670   ConstantClass *getOrCreate(const TypeClass *Ty, const ValType &V) {
 671     MapKey Lookup(Ty, V);
 672     ConstantClass* Result = 0;
 673
 674     typename MapTy::iterator I = Map.find(Lookup);
 675     // Is it in the map?
 676     if (I != Map.end())
 677       Result = I->second;
 678
 679     if (!Result) {
 680       // If no preexisting value, create one now...
 681       Result = Create(Ty, V, I);
 682     }
 683
 684     return Result;
 685   }
 686
 687   void UpdateAbstractTypeMap(const DerivedType *Ty,
 688                              typename MapTy::iterator I) {
 689     assert(AbstractTypeMap.count(Ty) &&
 690            "Abstract type not in AbstractTypeMap?");
 691     typename MapTy::iterator &ATMEntryIt = AbstractTypeMap[Ty];
 692     if (ATMEntryIt == I) {
 693       // Yes, we are removing the representative entry for this type.
 694       // See if there are any other entries of the same type.
 695       typename MapTy::iterator TmpIt = ATMEntryIt;
 696
 697       // First check the entry before this one...
 698       if (TmpIt != Map.begin()) {
 699         --TmpIt;
 700         if (TmpIt->first.first != Ty) // Not the same type, move back...
 701           ++TmpIt;
 702       }
 703
 704       // If we didn't find the same type, try to move forward...
 705       if (TmpIt == ATMEntryIt) {
 706         ++TmpIt;
 707         if (TmpIt == Map.end() || TmpIt->first.first != Ty)
 708           --TmpIt;   // No entry afterwards with the same type
 709       }
 710
 711       // If there is another entry in the map of the same abstract type,
 712       // update the AbstractTypeMap entry now.
 713       if (TmpIt != ATMEntryIt) {
 714         ATMEntryIt = TmpIt;
 715       } else {
 716         // Otherwise, we are removing the last instance of this type
 717         // from the table.  Remove from the ATM, and from user list.
 718         cast<DerivedType>(Ty)->removeAbstractTypeUser(this);
 719         AbstractTypeMap.erase(Ty);
 720       }
 721     }
 722   }
 723
 724   void remove(ConstantClass *CP) {
 725     typename MapTy::iterator I = FindExistingElement(CP);
 726     assert(I != Map.end() && "Constant not found in constant table!");
 727     assert(I->second == CP && "Didn't find correct element?");
 728
 729     if (HasLargeKey)  // Remember the reverse mapping if needed.
 730       InverseMap.erase(CP);
 731
 732     // Now that we found the entry, make sure this isn't the entry that
 733     // the AbstractTypeMap points to.
 734     const TypeClass *Ty = I->first.first;
 735     if (Ty->isAbstract())
 736       UpdateAbstractTypeMap(static_cast<const DerivedType *>(Ty), I);
 737
 738     Map.erase(I);
 739   }
 740
 741   /// MoveConstantToNewSlot - If we are about to change C to be the element
 742   /// specified by I, update our internal data structures to reflect this
 743   /// fact.
 744   void MoveConstantToNewSlot(ConstantClass *C, typename MapTy::iterator I) {
 745     // First, remove the old location of the specified constant in the map.
 746     typename MapTy::iterator OldI = FindExistingElement(C);
 747     assert(OldI != Map.end() && "Constant not found in constant table!");
 748     assert(OldI->second == C && "Didn't find correct element?");
 749
 750     // If this constant is the representative element for its abstract type,
 751     // update the AbstractTypeMap so that the representative element is I.
 752     //
 753     // This must use getRawType() because if the type is under refinement, we
 754     // will get the refineAbstractType callback below, and we don't want to
 755     // kick union find in on the constant.
 756     if (C->getRawType()->isAbstract()) {
 757       typename AbstractTypeMapTy::iterator ATI =
 758           AbstractTypeMap.find(cast<DerivedType>(C->getRawType()));
 759       assert(ATI != AbstractTypeMap.end() &&
 760              "Abstract type not in AbstractTypeMap?");
 761       if (ATI->second == OldI)
 762         ATI->second = I;
 763     }
 764
 765     // Remove the old entry from the map.
 766     Map.erase(OldI);
 767
 768     // Update the inverse map so that we know that this constant is now
 769     // located at descriptor I.
 770     if (HasLargeKey) {
 771       assert(I->second == C && "Bad inversemap entry!");
 772       InverseMap[C] = I;
 773     }
 774   }
 775
 776   void refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
 777     typename AbstractTypeMapTy::iterator I = AbstractTypeMap.find(OldTy);
 778
 779     assert(I != AbstractTypeMap.end() &&
 780            "Abstract type not in AbstractTypeMap?");
 781
 782     // Convert a constant at a time until the last one is gone.  The last one
 783     // leaving will remove() itself, causing the AbstractTypeMapEntry to be
 784     // eliminated eventually.
 785     do {
 786       ConstantClass *C = I->second->second;
 787       MapKey Key(cast<TypeClass>(NewTy),
 788                  ConstantKeyData<ConstantClass>::getValType(C));
 789
 790       std::pair<typename MapTy::iterator, bool> IP =
 791         Map.insert(std::make_pair(Key, C));
 792       if (IP.second) {
 793         // The map didn't previously have an appropriate constant in the
 794         // new type.
 795
 796         // Remove the old entry.
 797         typename MapTy::iterator OldI =
 798           Map.find(MapKey(cast<TypeClass>(OldTy), IP.first->first.second));
 799         assert(OldI != Map.end() && "Constant not in map!");
 800         UpdateAbstractTypeMap(OldTy, OldI);
 801         Map.erase(OldI);
 802
 803         // Set the constant's type. This is done in place!
 804         setType(C, NewTy);
 805
 806         // Update the inverse map so that we know that this constant is now
 807         // located at descriptor I.
 808         if (HasLargeKey)
 809           InverseMap[C] = IP.first;
 810
 811         AddAbstractTypeUser(NewTy, IP.first);
 812       } else {
 813         // The map already had an appropriate constant in the new type, so
 814         // there's no longer a need for the old constant.
 815         C->uncheckedReplaceAllUsesWith(IP.first->second);
 816         C->destroyConstant();    // This constant is now dead, destroy it.
 817       }
 818       I = AbstractTypeMap.find(OldTy);
 819     } while (I != AbstractTypeMap.end());
 820   }
 821
 822   // If the type became concrete without being refined to any other existing
 823   // type, we just remove ourselves from the ATU list.
 824   void typeBecameConcrete(const DerivedType *AbsTy) {
 825     AbsTy->removeAbstractTypeUser(this);
 826   }
 827
 828   void dump() const {
 829     DEBUG(dbgs() << "Constant.cpp: ConstantUniqueMap\n");
 830   }
 831 };
 832
 833 }
 834
 835 #endif