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> :
 243   public FixedNumOperandTraits<UnaryConstantExpr, 1> {
 244 };
 245 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(UnaryConstantExpr, Value)
 246
 247 template <>
 248 struct OperandTraits<BinaryConstantExpr> :
 249   public FixedNumOperandTraits<BinaryConstantExpr, 2> {
 250 };
 251 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BinaryConstantExpr, Value)
 252
 253 template <>
 254 struct OperandTraits<SelectConstantExpr> :
 255   public FixedNumOperandTraits<SelectConstantExpr, 3> {
 256 };
 257 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(SelectConstantExpr, Value)
 258
 259 template <>
 260 struct OperandTraits<ExtractElementConstantExpr> :
 261   public FixedNumOperandTraits<ExtractElementConstantExpr, 2> {
 262 };
 263 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractElementConstantExpr, Value)
 264
 265 template <>
 266 struct OperandTraits<InsertElementConstantExpr> :
 267   public FixedNumOperandTraits<InsertElementConstantExpr, 3> {
 268 };
 269 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertElementConstantExpr, Value)
 270
 271 template <>
 272 struct OperandTraits<ShuffleVectorConstantExpr> :
 273     public FixedNumOperandTraits<ShuffleVectorConstantExpr, 3> {
 274 };
 275 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ShuffleVectorConstantExpr, Value)
 276
 277 template <>
 278 struct OperandTraits<ExtractValueConstantExpr> :
 279   public FixedNumOperandTraits<ExtractValueConstantExpr, 1> {
 280 };
 281 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractValueConstantExpr, Value)
 282
 283 template <>
 284 struct OperandTraits<InsertValueConstantExpr> :
 285   public FixedNumOperandTraits<InsertValueConstantExpr, 2> {
 286 };
 287 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertValueConstantExpr, Value)
 288
 289 template <>
 290 struct OperandTraits<GetElementPtrConstantExpr> :
 291   public VariadicOperandTraits<GetElementPtrConstantExpr, 1> {
 292 };
 293
 294 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GetElementPtrConstantExpr, Value)
 295
 296
 297 template <>
 298 struct OperandTraits<CompareConstantExpr> :
 299   public FixedNumOperandTraits<CompareConstantExpr, 2> {
 300 };
 301 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CompareConstantExpr, Value)
 302
 303 struct ExprMapKeyType {
 304   typedef SmallVector<unsigned, 4> IndexList;
 305
 306   ExprMapKeyType(unsigned opc,
 307       const std::vector<Constant*> &ops,
 308       unsigned short flags = 0,
 309       unsigned short optionalflags = 0,
 310       const IndexList &inds = IndexList())
 311         : opcode(opc), subclassoptionaldata(optionalflags), subclassdata(flags),
 312         operands(ops), indices(inds) {}
 313   uint8_t opcode;
 314   uint8_t subclassoptionaldata;
 315   uint16_t subclassdata;
 316   std::vector<Constant*> operands;
 317   IndexList indices;
 318   bool operator==(const ExprMapKeyType& that) const {
 319     return this->opcode == that.opcode &&
 320            this->subclassdata == that.subclassdata &&
 321            this->subclassoptionaldata == that.subclassoptionaldata &&
 322            this->operands == that.operands &&
 323            this->indices == that.indices;
 324   }
 325   bool operator<(const ExprMapKeyType & that) const {
 326     if (this->opcode != that.opcode) return this->opcode < that.opcode;
 327     if (this->operands != that.operands) return this->operands < that.operands;
 328     if (this->subclassdata != that.subclassdata)
 329       return this->subclassdata < that.subclassdata;
 330     if (this->subclassoptionaldata != that.subclassoptionaldata)
 331       return this->subclassoptionaldata < that.subclassoptionaldata;
 332     if (this->indices != that.indices) return this->indices < that.indices;
 333     return false;
 334   }
 335
 336   bool operator!=(const ExprMapKeyType& that) const {
 337     return !(*this == that);
 338   }
 339 };
 340
 341 struct InlineAsmKeyType {
 342   InlineAsmKeyType(StringRef AsmString,
 343                    StringRef Constraints, bool hasSideEffects,
 344                    bool isAlignStack)
 345     : asm_string(AsmString), constraints(Constraints),
 346       has_side_effects(hasSideEffects), is_align_stack(isAlignStack) {}
 347   std::string asm_string;
 348   std::string constraints;
 349   bool has_side_effects;
 350   bool is_align_stack;
 351   bool operator==(const InlineAsmKeyType& that) const {
 352     return this->asm_string == that.asm_string &&
 353            this->constraints == that.constraints &&
 354            this->has_side_effects == that.has_side_effects &&
 355            this->is_align_stack == that.is_align_stack;
 356   }
 357   bool operator<(const InlineAsmKeyType& that) const {
 358     if (this->asm_string != that.asm_string)
 359       return this->asm_string < that.asm_string;
 360     if (this->constraints != that.constraints)
 361       return this->constraints < that.constraints;
 362     if (this->has_side_effects != that.has_side_effects)
 363       return this->has_side_effects < that.has_side_effects;
 364     if (this->is_align_stack != that.is_align_stack)
 365       return this->is_align_stack < that.is_align_stack;
 366     return false;
 367   }
 368
 369   bool operator!=(const InlineAsmKeyType& that) const {
 370     return !(*this == that);
 371   }
 372 };
 373
 374 // The number of operands for each ConstantCreator::create method is
 375 // determined by the ConstantTraits template.
 376 // ConstantCreator - A class that is used to create constants by
 377 // ConstantUniqueMap*.  This class should be partially specialized if there is
 378 // something strange that needs to be done to interface to the ctor for the
 379 // constant.
 380 //
 381 template<typename T, typename Alloc>
 382 struct ConstantTraits< std::vector<T, Alloc> > {
 383   static unsigned uses(const std::vector<T, Alloc>& v) {
 384     return v.size();
 385   }
 386 };
 387
 388 template<>
 389 struct ConstantTraits<Constant *> {
 390   static unsigned uses(Constant * const & v) {
 391     return 1;
 392   }
 393 };
 394
 395 template<class ConstantClass, class TypeClass, class ValType>
 396 struct ConstantCreator {
 397   static ConstantClass *create(const TypeClass *Ty, const ValType &V) {
 398     return new(ConstantTraits<ValType>::uses(V)) ConstantClass(Ty, V);
 399   }
 400 };
 401
 402 template<class ConstantClass>
 403 struct ConstantKeyData {
 404   typedef void ValType;
 405   static ValType getValType(ConstantClass *C) {
 406     llvm_unreachable("Unknown Constant type!");
 407   }
 408 };
 409
 410 template<>
 411 struct ConstantCreator<ConstantExpr, Type, ExprMapKeyType> {
 412   static ConstantExpr *create(const Type *Ty, const ExprMapKeyType &V,
 413       unsigned short pred = 0) {
 414     if (Instruction::isCast(V.opcode))
 415       return new UnaryConstantExpr(V.opcode, V.operands[0], Ty);
 416     if ((V.opcode >= Instruction::BinaryOpsBegin &&
 417          V.opcode < Instruction::BinaryOpsEnd))
 418       return new BinaryConstantExpr(V.opcode, V.operands[0], V.operands[1],
 419                                     V.subclassoptionaldata);
 420     if (V.opcode == Instruction::Select)
 421       return new SelectConstantExpr(V.operands[0], V.operands[1],
 422                                     V.operands[2]);
 423     if (V.opcode == Instruction::ExtractElement)
 424       return new ExtractElementConstantExpr(V.operands[0], V.operands[1]);
 425     if (V.opcode == Instruction::InsertElement)
 426       return new InsertElementConstantExpr(V.operands[0], V.operands[1],
 427                                            V.operands[2]);
 428     if (V.opcode == Instruction::ShuffleVector)
 429       return new ShuffleVectorConstantExpr(V.operands[0], V.operands[1],
 430                                            V.operands[2]);
 431     if (V.opcode == Instruction::InsertValue)
 432       return new InsertValueConstantExpr(V.operands[0], V.operands[1],
 433                                          V.indices, Ty);
 434     if (V.opcode == Instruction::ExtractValue)
 435       return new ExtractValueConstantExpr(V.operands[0], V.indices, Ty);
 436     if (V.opcode == Instruction::GetElementPtr) {
 437       std::vector<Constant*> IdxList(V.operands.begin()+1, V.operands.end());
 438       return GetElementPtrConstantExpr::Create(V.operands[0], IdxList, Ty,
 439                                                V.subclassoptionaldata);
 440     }
 441
 442     // The compare instructions are weird. We have to encode the predicate
 443     // value and it is combined with the instruction opcode by multiplying
 444     // the opcode by one hundred. We must decode this to get the predicate.
 445     if (V.opcode == Instruction::ICmp)
 446       return new CompareConstantExpr(Ty, Instruction::ICmp, V.subclassdata,
 447                                      V.operands[0], V.operands[1]);
 448     if (V.opcode == Instruction::FCmp)
 449       return new CompareConstantExpr(Ty, Instruction::FCmp, V.subclassdata,
 450                                      V.operands[0], V.operands[1]);
 451     llvm_unreachable("Invalid ConstantExpr!");
 452     return 0;
 453   }
 454 };
 455
 456 template<>
 457 struct ConstantKeyData<ConstantExpr> {
 458   typedef ExprMapKeyType ValType;
 459   static ValType getValType(ConstantExpr *CE) {
 460     std::vector<Constant*> Operands;
 461     Operands.reserve(CE->getNumOperands());
 462     for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
 463       Operands.push_back(cast<Constant>(CE->getOperand(i)));
 464     return ExprMapKeyType(CE->getOpcode(), Operands,
 465         CE->isCompare() ? CE->getPredicate() : 0,
 466         CE->getRawSubclassOptionalData(),
 467         CE->hasIndices() ?
 468           CE->getIndices() : SmallVector<unsigned, 4>());
 469   }
 470 };
 471
 472 // ConstantAggregateZero does not take extra "value" argument...
 473 template<class ValType>
 474 struct ConstantCreator<ConstantAggregateZero, Type, ValType> {
 475   static ConstantAggregateZero *create(const Type *Ty, const ValType &V){
 476     return new ConstantAggregateZero(Ty);
 477   }
 478 };
 479
 480 template<>
 481 struct ConstantKeyData<ConstantVector> {
 482   typedef std::vector<Constant*> ValType;
 483   static ValType getValType(ConstantVector *CP) {
 484     std::vector<Constant*> Elements;
 485     Elements.reserve(CP->getNumOperands());
 486     for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
 487       Elements.push_back(CP->getOperand(i));
 488     return Elements;
 489   }
 490 };
 491
 492 template<>
 493 struct ConstantKeyData<ConstantAggregateZero> {
 494   typedef char ValType;
 495   static ValType getValType(ConstantAggregateZero *C) {
 496     return 0;
 497   }
 498 };
 499
 500 template<>
 501 struct ConstantKeyData<ConstantArray> {
 502   typedef std::vector<Constant*> ValType;
 503   static ValType getValType(ConstantArray *CA) {
 504     std::vector<Constant*> Elements;
 505     Elements.reserve(CA->getNumOperands());
 506     for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
 507       Elements.push_back(cast<Constant>(CA->getOperand(i)));
 508     return Elements;
 509   }
 510 };
 511
 512 template<>
 513 struct ConstantKeyData<ConstantStruct> {
 514   typedef std::vector<Constant*> ValType;
 515   static ValType getValType(ConstantStruct *CS) {
 516     std::vector<Constant*> Elements;
 517     Elements.reserve(CS->getNumOperands());
 518     for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i)
 519       Elements.push_back(cast<Constant>(CS->getOperand(i)));
 520     return Elements;
 521   }
 522 };
 523
 524 // ConstantPointerNull does not take extra "value" argument...
 525 template<class ValType>
 526 struct ConstantCreator<ConstantPointerNull, PointerType, ValType> {
 527   static ConstantPointerNull *create(const PointerType *Ty, const ValType &V){
 528     return new ConstantPointerNull(Ty);
 529   }
 530 };
 531
 532 template<>
 533 struct ConstantKeyData<ConstantPointerNull> {
 534   typedef char ValType;
 535   static ValType getValType(ConstantPointerNull *C) {
 536     return 0;
 537   }
 538 };
 539
 540 // UndefValue does not take extra "value" argument...
 541 template<class ValType>
 542 struct ConstantCreator<UndefValue, Type, ValType> {
 543   static UndefValue *create(const Type *Ty, const ValType &V) {
 544     return new UndefValue(Ty);
 545   }
 546 };
 547
 548 template<>
 549 struct ConstantKeyData<UndefValue> {
 550   typedef char ValType;
 551   static ValType getValType(UndefValue *C) {
 552     return 0;
 553   }
 554 };
 555
 556 template<>
 557 struct ConstantCreator<InlineAsm, PointerType, InlineAsmKeyType> {
 558   static InlineAsm *create(const PointerType *Ty, const InlineAsmKeyType &Key) {
 559     return new InlineAsm(Ty, Key.asm_string, Key.constraints,
 560                          Key.has_side_effects, Key.is_align_stack);
 561   }
 562 };
 563
 564 template<>
 565 struct ConstantKeyData<InlineAsm> {
 566   typedef InlineAsmKeyType ValType;
 567   static ValType getValType(InlineAsm *Asm) {
 568     return InlineAsmKeyType(Asm->getAsmString(), Asm->getConstraintString(),
 569                             Asm->hasSideEffects(), Asm->isAlignStack());
 570   }
 571 };
 572
 573 template<class ValType, class TypeClass, class ConstantClass,
 574          bool HasLargeKey = false /*true for arrays and structs*/ >
 575 class ConstantUniqueMap : public AbstractTypeUser {
 576 public:
 577   typedef std::pair<const TypeClass*, ValType> MapKey;
 578   typedef std::map<MapKey, ConstantClass *> MapTy;
 579   typedef std::map<ConstantClass *, typename MapTy::iterator> InverseMapTy;
 580   typedef std::map<const DerivedType*, typename MapTy::iterator>
 581     AbstractTypeMapTy;
 582 private:
 583   /// Map - This is the main map from the element descriptor to the Constants.
 584   /// This is the primary way we avoid creating two of the same shape
 585   /// constant.
 586   MapTy Map;
 587
 588   /// InverseMap - If "HasLargeKey" is true, this contains an inverse mapping
 589   /// from the constants to their element in Map.  This is important for
 590   /// removal of constants from the array, which would otherwise have to scan
 591   /// through the map with very large keys.
 592   InverseMapTy InverseMap;
 593
 594   /// AbstractTypeMap - Map for abstract type constants.
 595   ///
 596   AbstractTypeMapTy AbstractTypeMap;
 597
 598 public:
 599   typename MapTy::iterator map_begin() { return Map.begin(); }
 600   typename MapTy::iterator map_end() { return Map.end(); }
 601
 602   void freeConstants() {
 603     for (typename MapTy::iterator I=Map.begin(), E=Map.end();
 604          I != E; ++I) {
 605       // Asserts that use_empty().
 606       delete I->second;
 607     }
 608   }
 609
 610   /// InsertOrGetItem - Return an iterator for the specified element.
 611   /// If the element exists in the map, the returned iterator points to the
 612   /// entry and Exists=true.  If not, the iterator points to the newly
 613   /// inserted entry and returns Exists=false.  Newly inserted entries have
 614   /// I->second == 0, and should be filled in.
 615   typename MapTy::iterator InsertOrGetItem(std::pair<MapKey, ConstantClass *>
 616                                  &InsertVal,
 617                                  bool &Exists) {
 618     std::pair<typename MapTy::iterator, bool> IP = Map.insert(InsertVal);
 619     Exists = !IP.second;
 620     return IP.first;
 621   }
 622
 623 private:
 624   typename MapTy::iterator FindExistingElement(ConstantClass *CP) {
 625     if (HasLargeKey) {
 626       typename InverseMapTy::iterator IMI = InverseMap.find(CP);
 627       assert(IMI != InverseMap.end() && IMI->second != Map.end() &&
 628              IMI->second->second == CP &&
 629              "InverseMap corrupt!");
 630       return IMI->second;
 631     }
 632
 633     typename MapTy::iterator I =
 634       Map.find(MapKey(static_cast<const TypeClass*>(CP->getRawType()),
 635                       ConstantKeyData<ConstantClass>::getValType(CP)));
 636     if (I == Map.end() || I->second != CP) {
 637       // FIXME: This should not use a linear scan.  If this gets to be a
 638       // performance problem, someone should look at this.
 639       for (I = Map.begin(); I != Map.end() && I->second != CP; ++I)
 640         /* empty */;
 641     }
 642     return I;
 643   }
 644
 645   void AddAbstractTypeUser(const Type *Ty, typename MapTy::iterator I) {
 646     // If the type of the constant is abstract, make sure that an entry
 647     // exists for it in the AbstractTypeMap.
 648     if (Ty->isAbstract()) {
 649       const DerivedType *DTy = static_cast<const DerivedType *>(Ty);
 650       typename AbstractTypeMapTy::iterator TI = AbstractTypeMap.find(DTy);
 651
 652       if (TI == AbstractTypeMap.end()) {
 653         // Add ourselves to the ATU list of the type.
 654         cast<DerivedType>(DTy)->addAbstractTypeUser(this);
 655
 656         AbstractTypeMap.insert(TI, std::make_pair(DTy, I));
 657       }
 658     }
 659   }
 660
 661   ConstantClass* Create(const TypeClass *Ty, const ValType &V,
 662                         typename MapTy::iterator I) {
 663     ConstantClass* Result =
 664       ConstantCreator<ConstantClass,TypeClass,ValType>::create(Ty, V);
 665
 666     assert(Result->getType() == Ty && "Type specified is not correct!");
 667     I = Map.insert(I, std::make_pair(MapKey(Ty, V), Result));
 668
 669     if (HasLargeKey)  // Remember the reverse mapping if needed.
 670       InverseMap.insert(std::make_pair(Result, I));
 671
 672     AddAbstractTypeUser(Ty, I);
 673
 674     return Result;
 675   }
 676 public:
 677
 678   /// getOrCreate - Return the specified constant from the map, creating it if
 679   /// necessary.
 680   ConstantClass *getOrCreate(const TypeClass *Ty, const ValType &V) {
 681     MapKey Lookup(Ty, V);
 682     ConstantClass* Result = 0;
 683
 684     typename MapTy::iterator I = Map.find(Lookup);
 685     // Is it in the map?
 686     if (I != Map.end())
 687       Result = I->second;
 688
 689     if (!Result) {
 690       // If no preexisting value, create one now...
 691       Result = Create(Ty, V, I);
 692     }
 693
 694     return Result;
 695   }
 696
 697   void UpdateAbstractTypeMap(const DerivedType *Ty,
 698                              typename MapTy::iterator I) {
 699     assert(AbstractTypeMap.count(Ty) &&
 700            "Abstract type not in AbstractTypeMap?");
 701     typename MapTy::iterator &ATMEntryIt = AbstractTypeMap[Ty];
 702     if (ATMEntryIt == I) {
 703       // Yes, we are removing the representative entry for this type.
 704       // See if there are any other entries of the same type.
 705       typename MapTy::iterator TmpIt = ATMEntryIt;
 706
 707       // First check the entry before this one...
 708       if (TmpIt != Map.begin()) {
 709         --TmpIt;
 710         if (TmpIt->first.first != Ty) // Not the same type, move back...
 711           ++TmpIt;
 712       }
 713
 714       // If we didn't find the same type, try to move forward...
 715       if (TmpIt == ATMEntryIt) {
 716         ++TmpIt;
 717         if (TmpIt == Map.end() || TmpIt->first.first != Ty)
 718           --TmpIt;   // No entry afterwards with the same type
 719       }
 720
 721       // If there is another entry in the map of the same abstract type,
 722       // update the AbstractTypeMap entry now.
 723       if (TmpIt != ATMEntryIt) {
 724         ATMEntryIt = TmpIt;
 725       } else {
 726         // Otherwise, we are removing the last instance of this type
 727         // from the table.  Remove from the ATM, and from user list.
 728         cast<DerivedType>(Ty)->removeAbstractTypeUser(this);
 729         AbstractTypeMap.erase(Ty);
 730       }
 731     }
 732   }
 733
 734   void remove(ConstantClass *CP) {
 735     typename MapTy::iterator I = FindExistingElement(CP);
 736     assert(I != Map.end() && "Constant not found in constant table!");
 737     assert(I->second == CP && "Didn't find correct element?");
 738
 739     if (HasLargeKey)  // Remember the reverse mapping if needed.
 740       InverseMap.erase(CP);
 741
 742     // Now that we found the entry, make sure this isn't the entry that
 743     // the AbstractTypeMap points to.
 744     const TypeClass *Ty = I->first.first;
 745     if (Ty->isAbstract())
 746       UpdateAbstractTypeMap(static_cast<const DerivedType *>(Ty), I);
 747
 748     Map.erase(I);
 749   }
 750
 751   /// MoveConstantToNewSlot - If we are about to change C to be the element
 752   /// specified by I, update our internal data structures to reflect this
 753   /// fact.
 754   void MoveConstantToNewSlot(ConstantClass *C, typename MapTy::iterator I) {
 755     // First, remove the old location of the specified constant in the map.
 756     typename MapTy::iterator OldI = FindExistingElement(C);
 757     assert(OldI != Map.end() && "Constant not found in constant table!");
 758     assert(OldI->second == C && "Didn't find correct element?");
 759
 760     // If this constant is the representative element for its abstract type,
 761     // update the AbstractTypeMap so that the representative element is I.
 762     //
 763     // This must use getRawType() because if the type is under refinement, we
 764     // will get the refineAbstractType callback below, and we don't want to
 765     // kick union find in on the constant.
 766     if (C->getRawType()->isAbstract()) {
 767       typename AbstractTypeMapTy::iterator ATI =
 768           AbstractTypeMap.find(cast<DerivedType>(C->getRawType()));
 769       assert(ATI != AbstractTypeMap.end() &&
 770              "Abstract type not in AbstractTypeMap?");
 771       if (ATI->second == OldI)
 772         ATI->second = I;
 773     }
 774
 775     // Remove the old entry from the map.
 776     Map.erase(OldI);
 777
 778     // Update the inverse map so that we know that this constant is now
 779     // located at descriptor I.
 780     if (HasLargeKey) {
 781       assert(I->second == C && "Bad inversemap entry!");
 782       InverseMap[C] = I;
 783     }
 784   }
 785
 786   void refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
 787     typename AbstractTypeMapTy::iterator I = AbstractTypeMap.find(OldTy);
 788
 789     assert(I != AbstractTypeMap.end() &&
 790            "Abstract type not in AbstractTypeMap?");
 791
 792     // Convert a constant at a time until the last one is gone.  The last one
 793     // leaving will remove() itself, causing the AbstractTypeMapEntry to be
 794     // eliminated eventually.
 795     do {
 796       ConstantClass *C = I->second->second;
 797       MapKey Key(cast<TypeClass>(NewTy),
 798                  ConstantKeyData<ConstantClass>::getValType(C));
 799
 800       std::pair<typename MapTy::iterator, bool> IP =
 801         Map.insert(std::make_pair(Key, C));
 802       if (IP.second) {
 803         // The map didn't previously have an appropriate constant in the
 804         // new type.
 805
 806         // Remove the old entry.
 807         typename MapTy::iterator OldI =
 808           Map.find(MapKey(cast<TypeClass>(OldTy), IP.first->first.second));
 809         assert(OldI != Map.end() && "Constant not in map!");
 810         UpdateAbstractTypeMap(OldTy, OldI);
 811         Map.erase(OldI);
 812
 813         // Set the constant's type. This is done in place!
 814         setType(C, NewTy);
 815
 816         // Update the inverse map so that we know that this constant is now
 817         // located at descriptor I.
 818         if (HasLargeKey)
 819           InverseMap[C] = IP.first;
 820
 821         AddAbstractTypeUser(NewTy, IP.first);
 822       } else {
 823         // The map already had an appropriate constant in the new type, so
 824         // there's no longer a need for the old constant.
 825         C->uncheckedReplaceAllUsesWith(IP.first->second);
 826         C->destroyConstant();    // This constant is now dead, destroy it.
 827       }
 828       I = AbstractTypeMap.find(OldTy);
 829     } while (I != AbstractTypeMap.end());
 830   }
 831
 832   // If the type became concrete without being refined to any other existing
 833   // type, we just remove ourselves from the ATU list.
 834   void typeBecameConcrete(const DerivedType *AbsTy) {
 835     AbsTy->removeAbstractTypeUser(this);
 836   }
 837
 838   void dump() const {
 839     DEBUG(dbgs() << "Constant.cpp: ConstantUniqueMap\n");
 840   }
 841 };
 842
 843 }
 844
 845 #endif