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