lib/VMCore/Constants.cpp

   1 //===-- Constants.cpp - Implement Constant nodes --------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the Constant* classes...
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "LLVMContextImpl.h"
  15 #include "llvm/Constants.h"
  16 #include "ConstantFold.h"
  17 #include "llvm/DerivedTypes.h"
  18 #include "llvm/GlobalValue.h"
  19 #include "llvm/Instructions.h"
  20 #include "llvm/Module.h"
  21 #include "llvm/Operator.h"
  22 #include "llvm/ADT/FoldingSet.h"
  23 #include "llvm/ADT/StringExtras.h"
  24 #include "llvm/ADT/StringMap.h"
  25 #include "llvm/Support/Compiler.h"
  26 #include "llvm/Support/Debug.h"
  27 #include "llvm/Support/ErrorHandling.h"
  28 #include "llvm/Support/ManagedStatic.h"
  29 #include "llvm/Support/MathExtras.h"
  30 #include "llvm/System/Mutex.h"
  31 #include "llvm/System/RWMutex.h"
  32 #include "llvm/System/Threading.h"
  33 #include "llvm/ADT/DenseMap.h"
  34 #include "llvm/ADT/SmallVector.h"
  35 #include <algorithm>
  36 #include <map>
  37 using namespace llvm;
  38
  39 //===----------------------------------------------------------------------===//
  40 //                              Constant Class
  41 //===----------------------------------------------------------------------===//
  42
  43 // Constructor to create a '0' constant of arbitrary type...
  44 static const uint64_t zero[2] = {0, 0};
  45 Constant* Constant::getNullValue(const Type* Ty) {
  46   switch (Ty->getTypeID()) {
  47   case Type::IntegerTyID:
  48     return ConstantInt::get(Ty, 0);
  49   case Type::FloatTyID:
  50     return ConstantFP::get(Ty->getContext(), APFloat(APInt(32, 0)));
  51   case Type::DoubleTyID:
  52     return ConstantFP::get(Ty->getContext(), APFloat(APInt(64, 0)));
  53   case Type::X86_FP80TyID:
  54     return ConstantFP::get(Ty->getContext(), APFloat(APInt(80, 2, zero)));
  55   case Type::FP128TyID:
  56     return ConstantFP::get(Ty->getContext(),
  57                            APFloat(APInt(128, 2, zero), true));
  58   case Type::PPC_FP128TyID:
  59     return ConstantFP::get(Ty->getContext(), APFloat(APInt(128, 2, zero)));
  60   case Type::PointerTyID:
  61     return ConstantPointerNull::get(cast<PointerType>(Ty));
  62   case Type::StructTyID:
  63   case Type::ArrayTyID:
  64   case Type::VectorTyID:
  65     return ConstantAggregateZero::get(Ty);
  66   default:
  67     // Function, Label, or Opaque type?
  68     assert(!"Cannot create a null constant of that type!");
  69     return 0;
  70   }
  71 }
  72
  73 Constant* Constant::getIntegerValue(const Type* Ty, const APInt &V) {
  74   const Type *ScalarTy = Ty->getScalarType();
  75
  76   // Create the base integer constant.
  77   Constant *C = ConstantInt::get(Ty->getContext(), V);
  78
  79   // Convert an integer to a pointer, if necessary.
  80   if (const PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
  81     C = ConstantExpr::getIntToPtr(C, PTy);
  82
  83   // Broadcast a scalar to a vector, if necessary.
  84   if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
  85     C = ConstantVector::get(std::vector<Constant *>(VTy->getNumElements(), C));
  86
  87   return C;
  88 }
  89
  90 Constant* Constant::getAllOnesValue(const Type* Ty) {
  91   if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty))
  92     return ConstantInt::get(Ty->getContext(),
  93                             APInt::getAllOnesValue(ITy->getBitWidth()));
  94
  95   std::vector<Constant*> Elts;
  96   const VectorType* VTy = cast<VectorType>(Ty);
  97   Elts.resize(VTy->getNumElements(), getAllOnesValue(VTy->getElementType()));
  98   assert(Elts[0] && "Not a vector integer type!");
  99   return cast<ConstantVector>(ConstantVector::get(Elts));
 100 }
 101
 102 void Constant::destroyConstantImpl() {
 103   // When a Constant is destroyed, there may be lingering
 104   // references to the constant by other constants in the constant pool.  These
 105   // constants are implicitly dependent on the module that is being deleted,
 106   // but they don't know that.  Because we only find out when the CPV is
 107   // deleted, we must now notify all of our users (that should only be
 108   // Constants) that they are, in fact, invalid now and should be deleted.
 109   //
 110   while (!use_empty()) {
 111     Value *V = use_back();
 112 #ifndef NDEBUG      // Only in -g mode...
 113     if (!isa<Constant>(V))
 114       DOUT << "While deleting: " << *this
 115            << "\n\nUse still stuck around after Def is destroyed: "
 116            << *V << "\n\n";
 117 #endif
 118     assert(isa<Constant>(V) && "References remain to Constant being destroyed");
 119     Constant *CV = cast<Constant>(V);
 120     CV->destroyConstant();
 121
 122     // The constant should remove itself from our use list...
 123     assert((use_empty() || use_back() != V) && "Constant not removed!");
 124   }
 125
 126   // Value has no outstanding references it is safe to delete it now...
 127   delete this;
 128 }
 129
 130 /// canTrap - Return true if evaluation of this constant could trap.  This is
 131 /// true for things like constant expressions that could divide by zero.
 132 bool Constant::canTrap() const {
 133   assert(getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
 134   // The only thing that could possibly trap are constant exprs.
 135   const ConstantExpr *CE = dyn_cast<ConstantExpr>(this);
 136   if (!CE) return false;
 137
 138   // ConstantExpr traps if any operands can trap.
 139   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 140     if (getOperand(i)->canTrap())
 141       return true;
 142
 143   // Otherwise, only specific operations can trap.
 144   switch (CE->getOpcode()) {
 145   default:
 146     return false;
 147   case Instruction::UDiv:
 148   case Instruction::SDiv:
 149   case Instruction::FDiv:
 150   case Instruction::URem:
 151   case Instruction::SRem:
 152   case Instruction::FRem:
 153     // Div and rem can trap if the RHS is not known to be non-zero.
 154     if (!isa<ConstantInt>(getOperand(1)) || getOperand(1)->isNullValue())
 155       return true;
 156     return false;
 157   }
 158 }
 159
 160
 161 /// getRelocationInfo - This method classifies the entry according to
 162 /// whether or not it may generate a relocation entry.  This must be
 163 /// conservative, so if it might codegen to a relocatable entry, it should say
 164 /// so.  The return values are:
 165 ///
 166 ///  NoRelocation: This constant pool entry is guaranteed to never have a
 167 ///     relocation applied to it (because it holds a simple constant like
 168 ///     '4').
 169 ///  LocalRelocation: This entry has relocations, but the entries are
 170 ///     guaranteed to be resolvable by the static linker, so the dynamic
 171 ///     linker will never see them.
 172 ///  GlobalRelocations: This entry may have arbitrary relocations.
 173 ///
 174 /// FIXME: This really should not be in VMCore.
 175 Constant::PossibleRelocationsTy Constant::getRelocationInfo() const {
 176   if (const GlobalValue *GV = dyn_cast<GlobalValue>(this)) {
 177     if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
 178       return LocalRelocation;  // Local to this file/library.
 179     return GlobalRelocations;    // Global reference.
 180   }
 181
 182   PossibleRelocationsTy Result = NoRelocation;
 183   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 184     Result = std::max(Result, getOperand(i)->getRelocationInfo());
 185
 186   return Result;
 187 }
 188
 189
 190 /// getVectorElements - This method, which is only valid on constant of vector
 191 /// type, returns the elements of the vector in the specified smallvector.
 192 /// This handles breaking down a vector undef into undef elements, etc.  For
 193 /// constant exprs and other cases we can't handle, we return an empty vector.
 194 void Constant::getVectorElements(LLVMContext &Context,
 195                                  SmallVectorImpl<Constant*> &Elts) const {
 196   assert(isa<VectorType>(getType()) && "Not a vector constant!");
 197
 198   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this)) {
 199     for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i)
 200       Elts.push_back(CV->getOperand(i));
 201     return;
 202   }
 203
 204   const VectorType *VT = cast<VectorType>(getType());
 205   if (isa<ConstantAggregateZero>(this)) {
 206     Elts.assign(VT->getNumElements(),
 207                 Constant::getNullValue(VT->getElementType()));
 208     return;
 209   }
 210
 211   if (isa<UndefValue>(this)) {
 212     Elts.assign(VT->getNumElements(), UndefValue::get(VT->getElementType()));
 213     return;
 214   }
 215
 216   // Unknown type, must be constant expr etc.
 217 }
 218
 219
 220
 221 //===----------------------------------------------------------------------===//
 222 //                                ConstantInt
 223 //===----------------------------------------------------------------------===//
 224
 225 ConstantInt::ConstantInt(const IntegerType *Ty, const APInt& V)
 226   : Constant(Ty, ConstantIntVal, 0, 0), Val(V) {
 227   assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type");
 228 }
 229
 230 ConstantInt* ConstantInt::getTrue(LLVMContext &Context) {
 231   LLVMContextImpl *pImpl = Context.pImpl;
 232   sys::SmartScopedWriter<true>(pImpl->ConstantsLock);
 233   if (pImpl->TheTrueVal)
 234     return pImpl->TheTrueVal;
 235   else
 236     return (pImpl->TheTrueVal = ConstantInt::get(IntegerType::get(1), 1));
 237 }
 238
 239 ConstantInt* ConstantInt::getFalse(LLVMContext &Context) {
 240   LLVMContextImpl *pImpl = Context.pImpl;
 241   sys::SmartScopedWriter<true>(pImpl->ConstantsLock);
 242   if (pImpl->TheFalseVal)
 243     return pImpl->TheFalseVal;
 244   else
 245     return (pImpl->TheFalseVal = ConstantInt::get(IntegerType::get(1), 0));
 246 }
 247
 248
 249 // Get a ConstantInt from an APInt. Note that the value stored in the DenseMap
 250 // as the key, is a DenseMapAPIntKeyInfo::KeyTy which has provided the
 251 // operator== and operator!= to ensure that the DenseMap doesn't attempt to
 252 // compare APInt's of different widths, which would violate an APInt class
 253 // invariant which generates an assertion.
 254 ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt& V) {
 255   // Get the corresponding integer type for the bit width of the value.
 256   const IntegerType *ITy = IntegerType::get(V.getBitWidth());
 257   // get an existing value or the insertion position
 258   DenseMapAPIntKeyInfo::KeyTy Key(V, ITy);
 259
 260   Context.pImpl->ConstantsLock.reader_acquire();
 261   ConstantInt *&Slot = Context.pImpl->IntConstants[Key];
 262   Context.pImpl->ConstantsLock.reader_release();
 263
 264   if (!Slot) {
 265     sys::SmartScopedWriter<true> Writer(Context.pImpl->ConstantsLock);
 266     ConstantInt *&NewSlot = Context.pImpl->IntConstants[Key];
 267     if (!Slot) {
 268       NewSlot = new ConstantInt(ITy, V);
 269     }
 270
 271     return NewSlot;
 272   } else {
 273     return Slot;
 274   }
 275 }
 276
 277 Constant* ConstantInt::get(const Type* Ty, uint64_t V, bool isSigned) {
 278   Constant *C = get(cast<IntegerType>(Ty->getScalarType()),
 279                                V, isSigned);
 280
 281   // For vectors, broadcast the value.
 282   if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
 283     return ConstantVector::get(
 284       std::vector<Constant *>(VTy->getNumElements(), C));
 285
 286   return C;
 287 }
 288
 289 ConstantInt* ConstantInt::get(const IntegerType* Ty, uint64_t V,
 290                               bool isSigned) {
 291   return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
 292 }
 293
 294 ConstantInt* ConstantInt::getSigned(const IntegerType* Ty, int64_t V) {
 295   return get(Ty, V, true);
 296 }
 297
 298 Constant *ConstantInt::getSigned(const Type *Ty, int64_t V) {
 299   return get(Ty, V, true);
 300 }
 301
 302 Constant* ConstantInt::get(const Type* Ty, const APInt& V) {
 303   ConstantInt *C = get(Ty->getContext(), V);
 304   assert(C->getType() == Ty->getScalarType() &&
 305          "ConstantInt type doesn't match the type implied by its value!");
 306
 307   // For vectors, broadcast the value.
 308   if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
 309     return ConstantVector::get(
 310       std::vector<Constant *>(VTy->getNumElements(), C));
 311
 312   return C;
 313 }
 314
 315 //===----------------------------------------------------------------------===//
 316 //                                ConstantFP
 317 //===----------------------------------------------------------------------===//
 318
 319 static const fltSemantics *TypeToFloatSemantics(const Type *Ty) {
 320   if (Ty == Type::FloatTy)
 321     return &APFloat::IEEEsingle;
 322   if (Ty == Type::DoubleTy)
 323     return &APFloat::IEEEdouble;
 324   if (Ty == Type::X86_FP80Ty)
 325     return &APFloat::x87DoubleExtended;
 326   else if (Ty == Type::FP128Ty)
 327     return &APFloat::IEEEquad;
 328
 329   assert(Ty == Type::PPC_FP128Ty && "Unknown FP format");
 330   return &APFloat::PPCDoubleDouble;
 331 }
 332
 333 /// get() - This returns a constant fp for the specified value in the
 334 /// specified type.  This should only be used for simple constant values like
 335 /// 2.0/1.0 etc, that are known-valid both as double and as the target format.
 336 Constant* ConstantFP::get(const Type* Ty, double V) {
 337   LLVMContext &Context = Ty->getContext();
 338
 339   APFloat FV(V);
 340   bool ignored;
 341   FV.convert(*TypeToFloatSemantics(Ty->getScalarType()),
 342              APFloat::rmNearestTiesToEven, &ignored);
 343   Constant *C = get(Context, FV);
 344
 345   // For vectors, broadcast the value.
 346   if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
 347     return ConstantVector::get(
 348       std::vector<Constant *>(VTy->getNumElements(), C));
 349
 350   return C;
 351 }
 352
 353 ConstantFP* ConstantFP::getNegativeZero(const Type* Ty) {
 354   LLVMContext &Context = Ty->getContext();
 355   APFloat apf = cast <ConstantFP>(Constant::getNullValue(Ty))->getValueAPF();
 356   apf.changeSign();
 357   return get(Context, apf);
 358 }
 359
 360
 361 Constant* ConstantFP::getZeroValueForNegation(const Type* Ty) {
 362   if (const VectorType *PTy = dyn_cast<VectorType>(Ty))
 363     if (PTy->getElementType()->isFloatingPoint()) {
 364       std::vector<Constant*> zeros(PTy->getNumElements(),
 365                            getNegativeZero(PTy->getElementType()));
 366       return ConstantVector::get(PTy, zeros);
 367     }
 368
 369   if (Ty->isFloatingPoint())
 370     return getNegativeZero(Ty);
 371
 372   return Constant::getNullValue(Ty);
 373 }
 374
 375
 376 // ConstantFP accessors.
 377 ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
 378   DenseMapAPFloatKeyInfo::KeyTy Key(V);
 379
 380   LLVMContextImpl* pImpl = Context.pImpl;
 381
 382   pImpl->ConstantsLock.reader_acquire();
 383   ConstantFP *&Slot = pImpl->FPConstants[Key];
 384   pImpl->ConstantsLock.reader_release();
 385
 386   if (!Slot) {
 387     sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
 388     ConstantFP *&NewSlot = pImpl->FPConstants[Key];
 389     if (!NewSlot) {
 390       const Type *Ty;
 391       if (&V.getSemantics() == &APFloat::IEEEsingle)
 392         Ty = Type::FloatTy;
 393       else if (&V.getSemantics() == &APFloat::IEEEdouble)
 394         Ty = Type::DoubleTy;
 395       else if (&V.getSemantics() == &APFloat::x87DoubleExtended)
 396         Ty = Type::X86_FP80Ty;
 397       else if (&V.getSemantics() == &APFloat::IEEEquad)
 398         Ty = Type::FP128Ty;
 399       else {
 400         assert(&V.getSemantics() == &APFloat::PPCDoubleDouble &&
 401                "Unknown FP format");
 402         Ty = Type::PPC_FP128Ty;
 403       }
 404       NewSlot = new ConstantFP(Ty, V);
 405     }
 406
 407     return NewSlot;
 408   }
 409
 410   return Slot;
 411 }
 412
 413 ConstantFP::ConstantFP(const Type *Ty, const APFloat& V)
 414   : Constant(Ty, ConstantFPVal, 0, 0), Val(V) {
 415   assert(&V.getSemantics() == TypeToFloatSemantics(Ty) &&
 416          "FP type Mismatch");
 417 }
 418
 419 bool ConstantFP::isNullValue() const {
 420   return Val.isZero() && !Val.isNegative();
 421 }
 422
 423 bool ConstantFP::isExactlyValue(const APFloat& V) const {
 424   return Val.bitwiseIsEqual(V);
 425 }
 426
 427 //===----------------------------------------------------------------------===//
 428 //                            ConstantXXX Classes
 429 //===----------------------------------------------------------------------===//
 430
 431
 432 ConstantArray::ConstantArray(const ArrayType *T,
 433                              const std::vector<Constant*> &V)
 434   : Constant(T, ConstantArrayVal,
 435              OperandTraits<ConstantArray>::op_end(this) - V.size(),
 436              V.size()) {
 437   assert(V.size() == T->getNumElements() &&
 438          "Invalid initializer vector for constant array");
 439   Use *OL = OperandList;
 440   for (std::vector<Constant*>::const_iterator I = V.begin(), E = V.end();
 441        I != E; ++I, ++OL) {
 442     Constant *C = *I;
 443     assert((C->getType() == T->getElementType() ||
 444             (T->isAbstract() &&
 445              C->getType()->getTypeID() == T->getElementType()->getTypeID())) &&
 446            "Initializer for array element doesn't match array element type!");
 447     *OL = C;
 448   }
 449 }
 450
 451 Constant *ConstantArray::get(const ArrayType *Ty,
 452                              const std::vector<Constant*> &V) {
 453   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
 454   // If this is an all-zero array, return a ConstantAggregateZero object
 455   if (!V.empty()) {
 456     Constant *C = V[0];
 457     if (!C->isNullValue()) {
 458       // Implicitly locked.
 459       return pImpl->ArrayConstants.getOrCreate(Ty, V);
 460     }
 461     for (unsigned i = 1, e = V.size(); i != e; ++i)
 462       if (V[i] != C) {
 463         // Implicitly locked.
 464         return pImpl->ArrayConstants.getOrCreate(Ty, V);
 465       }
 466   }
 467
 468   return ConstantAggregateZero::get(Ty);
 469 }
 470
 471
 472 Constant* ConstantArray::get(const ArrayType* T, Constant* const* Vals,
 473                              unsigned NumVals) {
 474   // FIXME: make this the primary ctor method.
 475   return get(T, std::vector<Constant*>(Vals, Vals+NumVals));
 476 }
 477
 478 /// ConstantArray::get(const string&) - Return an array that is initialized to
 479 /// contain the specified string.  If length is zero then a null terminator is
 480 /// added to the specified string so that it may be used in a natural way.
 481 /// Otherwise, the length parameter specifies how much of the string to use
 482 /// and it won't be null terminated.
 483 ///
 484 Constant* ConstantArray::get(const StringRef &Str, bool AddNull) {
 485   std::vector<Constant*> ElementVals;
 486   for (unsigned i = 0; i < Str.size(); ++i)
 487     ElementVals.push_back(ConstantInt::get(Type::Int8Ty, Str[i]));
 488
 489   // Add a null terminator to the string...
 490   if (AddNull) {
 491     ElementVals.push_back(ConstantInt::get(Type::Int8Ty, 0));
 492   }
 493
 494   ArrayType *ATy = ArrayType::get(Type::Int8Ty, ElementVals.size());
 495   return get(ATy, ElementVals);
 496 }
 497
 498
 499
 500 ConstantStruct::ConstantStruct(const StructType *T,
 501                                const std::vector<Constant*> &V)
 502   : Constant(T, ConstantStructVal,
 503              OperandTraits<ConstantStruct>::op_end(this) - V.size(),
 504              V.size()) {
 505   assert(V.size() == T->getNumElements() &&
 506          "Invalid initializer vector for constant structure");
 507   Use *OL = OperandList;
 508   for (std::vector<Constant*>::const_iterator I = V.begin(), E = V.end();
 509        I != E; ++I, ++OL) {
 510     Constant *C = *I;
 511     assert((C->getType() == T->getElementType(I-V.begin()) ||
 512             ((T->getElementType(I-V.begin())->isAbstract() ||
 513               C->getType()->isAbstract()) &&
 514              T->getElementType(I-V.begin())->getTypeID() ==
 515                    C->getType()->getTypeID())) &&
 516            "Initializer for struct element doesn't match struct element type!");
 517     *OL = C;
 518   }
 519 }
 520
 521 // ConstantStruct accessors.
 522 Constant* ConstantStruct::get(const StructType* T,
 523                               const std::vector<Constant*>& V) {
 524   LLVMContextImpl* pImpl = T->getContext().pImpl;
 525
 526   // Create a ConstantAggregateZero value if all elements are zeros...
 527   for (unsigned i = 0, e = V.size(); i != e; ++i)
 528     if (!V[i]->isNullValue())
 529       // Implicitly locked.
 530       return pImpl->StructConstants.getOrCreate(T, V);
 531
 532   return ConstantAggregateZero::get(T);
 533 }
 534
 535 Constant* ConstantStruct::get(LLVMContext &Context,
 536                               const std::vector<Constant*>& V, bool packed) {
 537   std::vector<const Type*> StructEls;
 538   StructEls.reserve(V.size());
 539   for (unsigned i = 0, e = V.size(); i != e; ++i)
 540     StructEls.push_back(V[i]->getType());
 541   return get(StructType::get(Context, StructEls, packed), V);
 542 }
 543
 544 Constant* ConstantStruct::get(LLVMContext &Context,
 545                               Constant* const *Vals, unsigned NumVals,
 546                               bool Packed) {
 547   // FIXME: make this the primary ctor method.
 548   return get(Context, std::vector<Constant*>(Vals, Vals+NumVals), Packed);
 549 }
 550
 551 ConstantVector::ConstantVector(const VectorType *T,
 552                                const std::vector<Constant*> &V)
 553   : Constant(T, ConstantVectorVal,
 554              OperandTraits<ConstantVector>::op_end(this) - V.size(),
 555              V.size()) {
 556   Use *OL = OperandList;
 557     for (std::vector<Constant*>::const_iterator I = V.begin(), E = V.end();
 558          I != E; ++I, ++OL) {
 559       Constant *C = *I;
 560       assert((C->getType() == T->getElementType() ||
 561             (T->isAbstract() &&
 562              C->getType()->getTypeID() == T->getElementType()->getTypeID())) &&
 563            "Initializer for vector element doesn't match vector element type!");
 564     *OL = C;
 565   }
 566 }
 567
 568 // ConstantVector accessors.
 569 Constant* ConstantVector::get(const VectorType* T,
 570                               const std::vector<Constant*>& V) {
 571    assert(!V.empty() && "Vectors can't be empty");
 572    LLVMContext &Context = T->getContext();
 573    LLVMContextImpl *pImpl = Context.pImpl;
 574
 575   // If this is an all-undef or alll-zero vector, return a
 576   // ConstantAggregateZero or UndefValue.
 577   Constant *C = V[0];
 578   bool isZero = C->isNullValue();
 579   bool isUndef = isa<UndefValue>(C);
 580
 581   if (isZero || isUndef) {
 582     for (unsigned i = 1, e = V.size(); i != e; ++i)
 583       if (V[i] != C) {
 584         isZero = isUndef = false;
 585         break;
 586       }
 587   }
 588
 589   if (isZero)
 590     return ConstantAggregateZero::get(T);
 591   if (isUndef)
 592     return UndefValue::get(T);
 593
 594   // Implicitly locked.
 595   return pImpl->VectorConstants.getOrCreate(T, V);
 596 }
 597
 598 Constant* ConstantVector::get(const std::vector<Constant*>& V) {
 599   assert(!V.empty() && "Cannot infer type if V is empty");
 600   return get(VectorType::get(V.front()->getType(),V.size()), V);
 601 }
 602
 603 Constant* ConstantVector::get(Constant* const* Vals, unsigned NumVals) {
 604   // FIXME: make this the primary ctor method.
 605   return get(std::vector<Constant*>(Vals, Vals+NumVals));
 606 }
 607
 608 // Utility function for determining if a ConstantExpr is a CastOp or not. This
 609 // can't be inline because we don't want to #include Instruction.h into
 610 // Constant.h
 611 bool ConstantExpr::isCast() const {
 612   return Instruction::isCast(getOpcode());
 613 }
 614
 615 bool ConstantExpr::isCompare() const {
 616   return getOpcode() == Instruction::ICmp || getOpcode() == Instruction::FCmp;
 617 }
 618
 619 bool ConstantExpr::hasIndices() const {
 620   return getOpcode() == Instruction::ExtractValue ||
 621          getOpcode() == Instruction::InsertValue;
 622 }
 623
 624 const SmallVector<unsigned, 4> &ConstantExpr::getIndices() const {
 625   if (const ExtractValueConstantExpr *EVCE =
 626         dyn_cast<ExtractValueConstantExpr>(this))
 627     return EVCE->Indices;
 628
 629   return cast<InsertValueConstantExpr>(this)->Indices;
 630 }
 631
 632 unsigned ConstantExpr::getPredicate() const {
 633   assert(getOpcode() == Instruction::FCmp ||
 634          getOpcode() == Instruction::ICmp);
 635   return ((const CompareConstantExpr*)this)->predicate;
 636 }
 637
 638 /// getWithOperandReplaced - Return a constant expression identical to this
 639 /// one, but with the specified operand set to the specified value.
 640 Constant *
 641 ConstantExpr::getWithOperandReplaced(unsigned OpNo, Constant *Op) const {
 642   assert(OpNo < getNumOperands() && "Operand num is out of range!");
 643   assert(Op->getType() == getOperand(OpNo)->getType() &&
 644          "Replacing operand with value of different type!");
 645   if (getOperand(OpNo) == Op)
 646     return const_cast<ConstantExpr*>(this);
 647
 648   Constant *Op0, *Op1, *Op2;
 649   switch (getOpcode()) {
 650   case Instruction::Trunc:
 651   case Instruction::ZExt:
 652   case Instruction::SExt:
 653   case Instruction::FPTrunc:
 654   case Instruction::FPExt:
 655   case Instruction::UIToFP:
 656   case Instruction::SIToFP:
 657   case Instruction::FPToUI:
 658   case Instruction::FPToSI:
 659   case Instruction::PtrToInt:
 660   case Instruction::IntToPtr:
 661   case Instruction::BitCast:
 662     return ConstantExpr::getCast(getOpcode(), Op, getType());
 663   case Instruction::Select:
 664     Op0 = (OpNo == 0) ? Op : getOperand(0);
 665     Op1 = (OpNo == 1) ? Op : getOperand(1);
 666     Op2 = (OpNo == 2) ? Op : getOperand(2);
 667     return ConstantExpr::getSelect(Op0, Op1, Op2);
 668   case Instruction::InsertElement:
 669     Op0 = (OpNo == 0) ? Op : getOperand(0);
 670     Op1 = (OpNo == 1) ? Op : getOperand(1);
 671     Op2 = (OpNo == 2) ? Op : getOperand(2);
 672     return ConstantExpr::getInsertElement(Op0, Op1, Op2);
 673   case Instruction::ExtractElement:
 674     Op0 = (OpNo == 0) ? Op : getOperand(0);
 675     Op1 = (OpNo == 1) ? Op : getOperand(1);
 676     return ConstantExpr::getExtractElement(Op0, Op1);
 677   case Instruction::ShuffleVector:
 678     Op0 = (OpNo == 0) ? Op : getOperand(0);
 679     Op1 = (OpNo == 1) ? Op : getOperand(1);
 680     Op2 = (OpNo == 2) ? Op : getOperand(2);
 681     return ConstantExpr::getShuffleVector(Op0, Op1, Op2);
 682   case Instruction::GetElementPtr: {
 683     SmallVector<Constant*, 8> Ops;
 684     Ops.resize(getNumOperands()-1);
 685     for (unsigned i = 1, e = getNumOperands(); i != e; ++i)
 686       Ops[i-1] = getOperand(i);
 687     if (OpNo == 0)
 688       return ConstantExpr::getGetElementPtr(Op, &Ops[0], Ops.size());
 689     Ops[OpNo-1] = Op;
 690     return ConstantExpr::getGetElementPtr(getOperand(0), &Ops[0], Ops.size());
 691   }
 692   default:
 693     assert(getNumOperands() == 2 && "Must be binary operator?");
 694     Op0 = (OpNo == 0) ? Op : getOperand(0);
 695     Op1 = (OpNo == 1) ? Op : getOperand(1);
 696     return ConstantExpr::get(getOpcode(), Op0, Op1);
 697   }
 698 }
 699
 700 /// getWithOperands - This returns the current constant expression with the
 701 /// operands replaced with the specified values.  The specified operands must
 702 /// match count and type with the existing ones.
 703 Constant *ConstantExpr::
 704 getWithOperands(Constant* const *Ops, unsigned NumOps) const {
 705   assert(NumOps == getNumOperands() && "Operand count mismatch!");
 706   bool AnyChange = false;
 707   for (unsigned i = 0; i != NumOps; ++i) {
 708     assert(Ops[i]->getType() == getOperand(i)->getType() &&
 709            "Operand type mismatch!");
 710     AnyChange |= Ops[i] != getOperand(i);
 711   }
 712   if (!AnyChange)  // No operands changed, return self.
 713     return const_cast<ConstantExpr*>(this);
 714
 715   switch (getOpcode()) {
 716   case Instruction::Trunc:
 717   case Instruction::ZExt:
 718   case Instruction::SExt:
 719   case Instruction::FPTrunc:
 720   case Instruction::FPExt:
 721   case Instruction::UIToFP:
 722   case Instruction::SIToFP:
 723   case Instruction::FPToUI:
 724   case Instruction::FPToSI:
 725   case Instruction::PtrToInt:
 726   case Instruction::IntToPtr:
 727   case Instruction::BitCast:
 728     return ConstantExpr::getCast(getOpcode(), Ops[0], getType());
 729   case Instruction::Select:
 730     return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
 731   case Instruction::InsertElement:
 732     return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
 733   case Instruction::ExtractElement:
 734     return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
 735   case Instruction::ShuffleVector:
 736     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
 737   case Instruction::GetElementPtr:
 738     return ConstantExpr::getGetElementPtr(Ops[0], &Ops[1], NumOps-1);
 739   case Instruction::ICmp:
 740   case Instruction::FCmp:
 741     return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1]);
 742   default:
 743     assert(getNumOperands() == 2 && "Must be binary operator?");
 744     return ConstantExpr::get(getOpcode(), Ops[0], Ops[1]);
 745   }
 746 }
 747
 748
 749 //===----------------------------------------------------------------------===//
 750 //                      isValueValidForType implementations
 751
 752 bool ConstantInt::isValueValidForType(const Type *Ty, uint64_t Val) {
 753   unsigned NumBits = cast<IntegerType>(Ty)->getBitWidth(); // assert okay
 754   if (Ty == Type::Int1Ty)
 755     return Val == 0 || Val == 1;
 756   if (NumBits >= 64)
 757     return true; // always true, has to fit in largest type
 758   uint64_t Max = (1ll << NumBits) - 1;
 759   return Val <= Max;
 760 }
 761
 762 bool ConstantInt::isValueValidForType(const Type *Ty, int64_t Val) {
 763   unsigned NumBits = cast<IntegerType>(Ty)->getBitWidth(); // assert okay
 764   if (Ty == Type::Int1Ty)
 765     return Val == 0 || Val == 1 || Val == -1;
 766   if (NumBits >= 64)
 767     return true; // always true, has to fit in largest type
 768   int64_t Min = -(1ll << (NumBits-1));
 769   int64_t Max = (1ll << (NumBits-1)) - 1;
 770   return (Val >= Min && Val <= Max);
 771 }
 772
 773 bool ConstantFP::isValueValidForType(const Type *Ty, const APFloat& Val) {
 774   // convert modifies in place, so make a copy.
 775   APFloat Val2 = APFloat(Val);
 776   bool losesInfo;
 777   switch (Ty->getTypeID()) {
 778   default:
 779     return false;         // These can't be represented as floating point!
 780
 781   // FIXME rounding mode needs to be more flexible
 782   case Type::FloatTyID: {
 783     if (&Val2.getSemantics() == &APFloat::IEEEsingle)
 784       return true;
 785     Val2.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &losesInfo);
 786     return !losesInfo;
 787   }
 788   case Type::DoubleTyID: {
 789     if (&Val2.getSemantics() == &APFloat::IEEEsingle ||
 790         &Val2.getSemantics() == &APFloat::IEEEdouble)
 791       return true;
 792     Val2.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo);
 793     return !losesInfo;
 794   }
 795   case Type::X86_FP80TyID:
 796     return &Val2.getSemantics() == &APFloat::IEEEsingle ||
 797            &Val2.getSemantics() == &APFloat::IEEEdouble ||
 798            &Val2.getSemantics() == &APFloat::x87DoubleExtended;
 799   case Type::FP128TyID:
 800     return &Val2.getSemantics() == &APFloat::IEEEsingle ||
 801            &Val2.getSemantics() == &APFloat::IEEEdouble ||
 802            &Val2.getSemantics() == &APFloat::IEEEquad;
 803   case Type::PPC_FP128TyID:
 804     return &Val2.getSemantics() == &APFloat::IEEEsingle ||
 805            &Val2.getSemantics() == &APFloat::IEEEdouble ||
 806            &Val2.getSemantics() == &APFloat::PPCDoubleDouble;
 807   }
 808 }
 809
 810 //===----------------------------------------------------------------------===//
 811 //                      Factory Function Implementation
 812
 813 static char getValType(ConstantAggregateZero *CPZ) { return 0; }
 814
 815 ConstantAggregateZero* ConstantAggregateZero::get(const Type* Ty) {
 816   assert((isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) &&
 817          "Cannot create an aggregate zero of non-aggregate type!");
 818
 819   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
 820   // Implicitly locked.
 821   return pImpl->AggZeroConstants.getOrCreate(Ty, 0);
 822 }
 823
 824 /// destroyConstant - Remove the constant from the constant table...
 825 ///
 826 void ConstantAggregateZero::destroyConstant() {
 827   // Implicitly locked.
 828   getType()->getContext().pImpl->AggZeroConstants.remove(this);
 829   destroyConstantImpl();
 830 }
 831
 832 /// destroyConstant - Remove the constant from the constant table...
 833 ///
 834 void ConstantArray::destroyConstant() {
 835   // Implicitly locked.
 836   getType()->getContext().pImpl->ArrayConstants.remove(this);
 837   destroyConstantImpl();
 838 }
 839
 840 /// isString - This method returns true if the array is an array of i8, and
 841 /// if the elements of the array are all ConstantInt's.
 842 bool ConstantArray::isString() const {
 843   // Check the element type for i8...
 844   if (getType()->getElementType() != Type::Int8Ty)
 845     return false;
 846   // Check the elements to make sure they are all integers, not constant
 847   // expressions.
 848   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 849     if (!isa<ConstantInt>(getOperand(i)))
 850       return false;
 851   return true;
 852 }
 853
 854 /// isCString - This method returns true if the array is a string (see
 855 /// isString) and it ends in a null byte \\0 and does not contains any other
 856 /// null bytes except its terminator.
 857 bool ConstantArray::isCString() const {
 858   // Check the element type for i8...
 859   if (getType()->getElementType() != Type::Int8Ty)
 860     return false;
 861
 862   // Last element must be a null.
 863   if (!getOperand(getNumOperands()-1)->isNullValue())
 864     return false;
 865   // Other elements must be non-null integers.
 866   for (unsigned i = 0, e = getNumOperands()-1; i != e; ++i) {
 867     if (!isa<ConstantInt>(getOperand(i)))
 868       return false;
 869     if (getOperand(i)->isNullValue())
 870       return false;
 871   }
 872   return true;
 873 }
 874
 875
 876 /// getAsString - If the sub-element type of this array is i8
 877 /// then this method converts the array to an std::string and returns it.
 878 /// Otherwise, it asserts out.
 879 ///
 880 std::string ConstantArray::getAsString() const {
 881   assert(isString() && "Not a string!");
 882   std::string Result;
 883   Result.reserve(getNumOperands());
 884   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 885     Result.push_back((char)cast<ConstantInt>(getOperand(i))->getZExtValue());
 886   return Result;
 887 }
 888
 889
 890 //---- ConstantStruct::get() implementation...
 891 //
 892
 893 namespace llvm {
 894
 895 }
 896
 897 // destroyConstant - Remove the constant from the constant table...
 898 //
 899 void ConstantStruct::destroyConstant() {
 900   // Implicitly locked.
 901   getType()->getContext().pImpl->StructConstants.remove(this);
 902   destroyConstantImpl();
 903 }
 904
 905 // destroyConstant - Remove the constant from the constant table...
 906 //
 907 void ConstantVector::destroyConstant() {
 908   // Implicitly locked.
 909   getType()->getContext().pImpl->VectorConstants.remove(this);
 910   destroyConstantImpl();
 911 }
 912
 913 /// This function will return true iff every element in this vector constant
 914 /// is set to all ones.
 915 /// @returns true iff this constant's emements are all set to all ones.
 916 /// @brief Determine if the value is all ones.
 917 bool ConstantVector::isAllOnesValue() const {
 918   // Check out first element.
 919   const Constant *Elt = getOperand(0);
 920   const ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
 921   if (!CI || !CI->isAllOnesValue()) return false;
 922   // Then make sure all remaining elements point to the same value.
 923   for (unsigned I = 1, E = getNumOperands(); I < E; ++I) {
 924     if (getOperand(I) != Elt) return false;
 925   }
 926   return true;
 927 }
 928
 929 /// getSplatValue - If this is a splat constant, where all of the
 930 /// elements have the same value, return that value. Otherwise return null.
 931 Constant *ConstantVector::getSplatValue() {
 932   // Check out first element.
 933   Constant *Elt = getOperand(0);
 934   // Then make sure all remaining elements point to the same value.
 935   for (unsigned I = 1, E = getNumOperands(); I < E; ++I)
 936     if (getOperand(I) != Elt) return 0;
 937   return Elt;
 938 }
 939
 940 //---- ConstantPointerNull::get() implementation...
 941 //
 942
 943 static char getValType(ConstantPointerNull *) {
 944   return 0;
 945 }
 946
 947
 948 ConstantPointerNull *ConstantPointerNull::get(const PointerType *Ty) {
 949   // Implicitly locked.
 950   return Ty->getContext().pImpl->NullPtrConstants.getOrCreate(Ty, 0);
 951 }
 952
 953 // destroyConstant - Remove the constant from the constant table...
 954 //
 955 void ConstantPointerNull::destroyConstant() {
 956   // Implicitly locked.
 957   getType()->getContext().pImpl->NullPtrConstants.remove(this);
 958   destroyConstantImpl();
 959 }
 960
 961
 962 //---- UndefValue::get() implementation...
 963 //
 964
 965 static char getValType(UndefValue *) {
 966   return 0;
 967 }
 968
 969 UndefValue *UndefValue::get(const Type *Ty) {
 970   // Implicitly locked.
 971   return Ty->getContext().pImpl->UndefValueConstants.getOrCreate(Ty, 0);
 972 }
 973
 974 // destroyConstant - Remove the constant from the constant table.
 975 //
 976 void UndefValue::destroyConstant() {
 977   // Implicitly locked.
 978   getType()->getContext().pImpl->UndefValueConstants.remove(this);
 979   destroyConstantImpl();
 980 }
 981
 982 //---- ConstantExpr::get() implementations...
 983 //
 984
 985 static ExprMapKeyType getValType(ConstantExpr *CE) {
 986   std::vector<Constant*> Operands;
 987   Operands.reserve(CE->getNumOperands());
 988   for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
 989     Operands.push_back(cast<Constant>(CE->getOperand(i)));
 990   return ExprMapKeyType(CE->getOpcode(), Operands,
 991       CE->isCompare() ? CE->getPredicate() : 0,
 992       CE->hasIndices() ?
 993         CE->getIndices() : SmallVector<unsigned, 4>());
 994 }
 995
 996 /// This is a utility function to handle folding of casts and lookup of the
 997 /// cast in the ExprConstants map. It is used by the various get* methods below.
 998 static inline Constant *getFoldedCast(
 999   Instruction::CastOps opc, Constant *C, const Type *Ty) {
1000   assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
1001   // Fold a few common cases
1002   if (Constant *FC = ConstantFoldCastInstruction(Ty->getContext(), opc, C, Ty))
1003     return FC;
1004
1005   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
1006
1007   // Look up the constant in the table first to ensure uniqueness
1008   std::vector<Constant*> argVec(1, C);
1009   ExprMapKeyType Key(opc, argVec);
1010
1011   // Implicitly locked.
1012   return pImpl->ExprConstants.getOrCreate(Ty, Key);
1013 }
1014
1015 Constant *ConstantExpr::getCast(unsigned oc, Constant *C, const Type *Ty) {
1016   Instruction::CastOps opc = Instruction::CastOps(oc);
1017   assert(Instruction::isCast(opc) && "opcode out of range");
1018   assert(C && Ty && "Null arguments to getCast");
1019   assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
1020
1021   switch (opc) {
1022     default:
1023       llvm_unreachable("Invalid cast opcode");
1024       break;
1025     case Instruction::Trunc:    return getTrunc(C, Ty);
1026     case Instruction::ZExt:     return getZExt(C, Ty);
1027     case Instruction::SExt:     return getSExt(C, Ty);
1028     case Instruction::FPTrunc:  return getFPTrunc(C, Ty);
1029     case Instruction::FPExt:    return getFPExtend(C, Ty);
1030     case Instruction::UIToFP:   return getUIToFP(C, Ty);
1031     case Instruction::SIToFP:   return getSIToFP(C, Ty);
1032     case Instruction::FPToUI:   return getFPToUI(C, Ty);
1033     case Instruction::FPToSI:   return getFPToSI(C, Ty);
1034     case Instruction::PtrToInt: return getPtrToInt(C, Ty);
1035     case Instruction::IntToPtr: return getIntToPtr(C, Ty);
1036     case Instruction::BitCast:  return getBitCast(C, Ty);
1037   }
1038   return 0;
1039 }
1040
1041 Constant *ConstantExpr::getZExtOrBitCast(Constant *C, const Type *Ty) {
1042   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1043     return getCast(Instruction::BitCast, C, Ty);
1044   return getCast(Instruction::ZExt, C, Ty);
1045 }
1046
1047 Constant *ConstantExpr::getSExtOrBitCast(Constant *C, const Type *Ty) {
1048   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1049     return getCast(Instruction::BitCast, C, Ty);
1050   return getCast(Instruction::SExt, C, Ty);
1051 }
1052
1053 Constant *ConstantExpr::getTruncOrBitCast(Constant *C, const Type *Ty) {
1054   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1055     return getCast(Instruction::BitCast, C, Ty);
1056   return getCast(Instruction::Trunc, C, Ty);
1057 }
1058
1059 Constant *ConstantExpr::getPointerCast(Constant *S, const Type *Ty) {
1060   assert(isa<PointerType>(S->getType()) && "Invalid cast");
1061   assert((Ty->isInteger() || isa<PointerType>(Ty)) && "Invalid cast");
1062
1063   if (Ty->isInteger())
1064     return getCast(Instruction::PtrToInt, S, Ty);
1065   return getCast(Instruction::BitCast, S, Ty);
1066 }
1067
1068 Constant *ConstantExpr::getIntegerCast(Constant *C, const Type *Ty,
1069                                        bool isSigned) {
1070   assert(C->getType()->isIntOrIntVector() &&
1071          Ty->isIntOrIntVector() && "Invalid cast");
1072   unsigned SrcBits = C->getType()->getScalarSizeInBits();
1073   unsigned DstBits = Ty->getScalarSizeInBits();
1074   Instruction::CastOps opcode =
1075     (SrcBits == DstBits ? Instruction::BitCast :
1076      (SrcBits > DstBits ? Instruction::Trunc :
1077       (isSigned ? Instruction::SExt : Instruction::ZExt)));
1078   return getCast(opcode, C, Ty);
1079 }
1080
1081 Constant *ConstantExpr::getFPCast(Constant *C, const Type *Ty) {
1082   assert(C->getType()->isFPOrFPVector() && Ty->isFPOrFPVector() &&
1083          "Invalid cast");
1084   unsigned SrcBits = C->getType()->getScalarSizeInBits();
1085   unsigned DstBits = Ty->getScalarSizeInBits();
1086   if (SrcBits == DstBits)
1087     return C; // Avoid a useless cast
1088   Instruction::CastOps opcode =
1089      (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt);
1090   return getCast(opcode, C, Ty);
1091 }
1092
1093 Constant *ConstantExpr::getTrunc(Constant *C, const Type *Ty) {
1094 #ifndef NDEBUG
1095   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1096   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1097 #endif
1098   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1099   assert(C->getType()->isIntOrIntVector() && "Trunc operand must be integer");
1100   assert(Ty->isIntOrIntVector() && "Trunc produces only integral");
1101   assert(C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
1102          "SrcTy must be larger than DestTy for Trunc!");
1103
1104   return getFoldedCast(Instruction::Trunc, C, Ty);
1105 }
1106
1107 Constant *ConstantExpr::getSExt(Constant *C, const Type *Ty) {
1108 #ifndef NDEBUG
1109   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1110   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1111 #endif
1112   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1113   assert(C->getType()->isIntOrIntVector() && "SExt operand must be integral");
1114   assert(Ty->isIntOrIntVector() && "SExt produces only integer");
1115   assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1116          "SrcTy must be smaller than DestTy for SExt!");
1117
1118   return getFoldedCast(Instruction::SExt, C, Ty);
1119 }
1120
1121 Constant *ConstantExpr::getZExt(Constant *C, const Type *Ty) {
1122 #ifndef NDEBUG
1123   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1124   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1125 #endif
1126   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1127   assert(C->getType()->isIntOrIntVector() && "ZEXt operand must be integral");
1128   assert(Ty->isIntOrIntVector() && "ZExt produces only integer");
1129   assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1130          "SrcTy must be smaller than DestTy for ZExt!");
1131
1132   return getFoldedCast(Instruction::ZExt, C, Ty);
1133 }
1134
1135 Constant *ConstantExpr::getFPTrunc(Constant *C, const Type *Ty) {
1136 #ifndef NDEBUG
1137   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1138   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1139 #endif
1140   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1141   assert(C->getType()->isFPOrFPVector() && Ty->isFPOrFPVector() &&
1142          C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
1143          "This is an illegal floating point truncation!");
1144   return getFoldedCast(Instruction::FPTrunc, C, Ty);
1145 }
1146
1147 Constant *ConstantExpr::getFPExtend(Constant *C, const Type *Ty) {
1148 #ifndef NDEBUG
1149   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1150   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1151 #endif
1152   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1153   assert(C->getType()->isFPOrFPVector() && Ty->isFPOrFPVector() &&
1154          C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1155          "This is an illegal floating point extension!");
1156   return getFoldedCast(Instruction::FPExt, C, Ty);
1157 }
1158
1159 Constant *ConstantExpr::getUIToFP(Constant *C, const Type *Ty) {
1160 #ifndef NDEBUG
1161   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1162   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1163 #endif
1164   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1165   assert(C->getType()->isIntOrIntVector() && Ty->isFPOrFPVector() &&
1166          "This is an illegal uint to floating point cast!");
1167   return getFoldedCast(Instruction::UIToFP, C, Ty);
1168 }
1169
1170 Constant *ConstantExpr::getSIToFP(Constant *C, const Type *Ty) {
1171 #ifndef NDEBUG
1172   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1173   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1174 #endif
1175   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1176   assert(C->getType()->isIntOrIntVector() && Ty->isFPOrFPVector() &&
1177          "This is an illegal sint to floating point cast!");
1178   return getFoldedCast(Instruction::SIToFP, C, Ty);
1179 }
1180
1181 Constant *ConstantExpr::getFPToUI(Constant *C, const Type *Ty) {
1182 #ifndef NDEBUG
1183   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1184   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1185 #endif
1186   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1187   assert(C->getType()->isFPOrFPVector() && Ty->isIntOrIntVector() &&
1188          "This is an illegal floating point to uint cast!");
1189   return getFoldedCast(Instruction::FPToUI, C, Ty);
1190 }
1191
1192 Constant *ConstantExpr::getFPToSI(Constant *C, const Type *Ty) {
1193 #ifndef NDEBUG
1194   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1195   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1196 #endif
1197   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1198   assert(C->getType()->isFPOrFPVector() && Ty->isIntOrIntVector() &&
1199          "This is an illegal floating point to sint cast!");
1200   return getFoldedCast(Instruction::FPToSI, C, Ty);
1201 }
1202
1203 Constant *ConstantExpr::getPtrToInt(Constant *C, const Type *DstTy) {
1204   assert(isa<PointerType>(C->getType()) && "PtrToInt source must be pointer");
1205   assert(DstTy->isInteger() && "PtrToInt destination must be integral");
1206   return getFoldedCast(Instruction::PtrToInt, C, DstTy);
1207 }
1208
1209 Constant *ConstantExpr::getIntToPtr(Constant *C, const Type *DstTy) {
1210   assert(C->getType()->isInteger() && "IntToPtr source must be integral");
1211   assert(isa<PointerType>(DstTy) && "IntToPtr destination must be a pointer");
1212   return getFoldedCast(Instruction::IntToPtr, C, DstTy);
1213 }
1214
1215 Constant *ConstantExpr::getBitCast(Constant *C, const Type *DstTy) {
1216   // BitCast implies a no-op cast of type only. No bits change.  However, you
1217   // can't cast pointers to anything but pointers.
1218 #ifndef NDEBUG
1219   const Type *SrcTy = C->getType();
1220   assert((isa<PointerType>(SrcTy) == isa<PointerType>(DstTy)) &&
1221          "BitCast cannot cast pointer to non-pointer and vice versa");
1222
1223   // Now we know we're not dealing with mismatched pointer casts (ptr->nonptr
1224   // or nonptr->ptr). For all the other types, the cast is okay if source and
1225   // destination bit widths are identical.
1226   unsigned SrcBitSize = SrcTy->getPrimitiveSizeInBits();
1227   unsigned DstBitSize = DstTy->getPrimitiveSizeInBits();
1228 #endif
1229   assert(SrcBitSize == DstBitSize && "BitCast requires types of same width");
1230
1231   // It is common to ask for a bitcast of a value to its own type, handle this
1232   // speedily.
1233   if (C->getType() == DstTy) return C;
1234
1235   return getFoldedCast(Instruction::BitCast, C, DstTy);
1236 }
1237
1238 Constant *ConstantExpr::getTy(const Type *ReqTy, unsigned Opcode,
1239                               Constant *C1, Constant *C2) {
1240   // Check the operands for consistency first
1241   assert(Opcode >= Instruction::BinaryOpsBegin &&
1242          Opcode <  Instruction::BinaryOpsEnd   &&
1243          "Invalid opcode in binary constant expression");
1244   assert(C1->getType() == C2->getType() &&
1245          "Operand types in binary constant expression should match");
1246
1247   if (ReqTy == C1->getType() || ReqTy == Type::Int1Ty)
1248     if (Constant *FC = ConstantFoldBinaryInstruction(ReqTy->getContext(),
1249                                                      Opcode, C1, C2))
1250       return FC;          // Fold a few common cases...
1251
1252   std::vector<Constant*> argVec(1, C1); argVec.push_back(C2);
1253   ExprMapKeyType Key(Opcode, argVec);
1254
1255   LLVMContextImpl *pImpl = ReqTy->getContext().pImpl;
1256
1257   // Implicitly locked.
1258   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1259 }
1260
1261 Constant *ConstantExpr::getCompareTy(unsigned short predicate,
1262                                      Constant *C1, Constant *C2) {
1263   switch (predicate) {
1264     default: llvm_unreachable("Invalid CmpInst predicate");
1265     case CmpInst::FCMP_FALSE: case CmpInst::FCMP_OEQ: case CmpInst::FCMP_OGT:
1266     case CmpInst::FCMP_OGE:   case CmpInst::FCMP_OLT: case CmpInst::FCMP_OLE:
1267     case CmpInst::FCMP_ONE:   case CmpInst::FCMP_ORD: case CmpInst::FCMP_UNO:
1268     case CmpInst::FCMP_UEQ:   case CmpInst::FCMP_UGT: case CmpInst::FCMP_UGE:
1269     case CmpInst::FCMP_ULT:   case CmpInst::FCMP_ULE: case CmpInst::FCMP_UNE:
1270     case CmpInst::FCMP_TRUE:
1271       return getFCmp(predicate, C1, C2);
1272
1273     case CmpInst::ICMP_EQ:  case CmpInst::ICMP_NE:  case CmpInst::ICMP_UGT:
1274     case CmpInst::ICMP_UGE: case CmpInst::ICMP_ULT: case CmpInst::ICMP_ULE:
1275     case CmpInst::ICMP_SGT: case CmpInst::ICMP_SGE: case CmpInst::ICMP_SLT:
1276     case CmpInst::ICMP_SLE:
1277       return getICmp(predicate, C1, C2);
1278   }
1279 }
1280
1281 Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2) {
1282   // API compatibility: Adjust integer opcodes to floating-point opcodes.
1283   if (C1->getType()->isFPOrFPVector()) {
1284     if (Opcode == Instruction::Add) Opcode = Instruction::FAdd;
1285     else if (Opcode == Instruction::Sub) Opcode = Instruction::FSub;
1286     else if (Opcode == Instruction::Mul) Opcode = Instruction::FMul;
1287   }
1288 #ifndef NDEBUG
1289   switch (Opcode) {
1290   case Instruction::Add:
1291   case Instruction::Sub:
1292   case Instruction::Mul:
1293     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1294     assert(C1->getType()->isIntOrIntVector() &&
1295            "Tried to create an integer operation on a non-integer type!");
1296     break;
1297   case Instruction::FAdd:
1298   case Instruction::FSub:
1299   case Instruction::FMul:
1300     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1301     assert(C1->getType()->isFPOrFPVector() &&
1302            "Tried to create a floating-point operation on a "
1303            "non-floating-point type!");
1304     break;
1305   case Instruction::UDiv:
1306   case Instruction::SDiv:
1307     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1308     assert(C1->getType()->isIntOrIntVector() &&
1309            "Tried to create an arithmetic operation on a non-arithmetic type!");
1310     break;
1311   case Instruction::FDiv:
1312     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1313     assert(C1->getType()->isFPOrFPVector() &&
1314            "Tried to create an arithmetic operation on a non-arithmetic type!");
1315     break;
1316   case Instruction::URem:
1317   case Instruction::SRem:
1318     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1319     assert(C1->getType()->isIntOrIntVector() &&
1320            "Tried to create an arithmetic operation on a non-arithmetic type!");
1321     break;
1322   case Instruction::FRem:
1323     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1324     assert(C1->getType()->isFPOrFPVector() &&
1325            "Tried to create an arithmetic operation on a non-arithmetic type!");
1326     break;
1327   case Instruction::And:
1328   case Instruction::Or:
1329   case Instruction::Xor:
1330     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1331     assert(C1->getType()->isIntOrIntVector() &&
1332            "Tried to create a logical operation on a non-integral type!");
1333     break;
1334   case Instruction::Shl:
1335   case Instruction::LShr:
1336   case Instruction::AShr:
1337     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1338     assert(C1->getType()->isIntOrIntVector() &&
1339            "Tried to create a shift operation on a non-integer type!");
1340     break;
1341   default:
1342     break;
1343   }
1344 #endif
1345
1346   return getTy(C1->getType(), Opcode, C1, C2);
1347 }
1348
1349 Constant* ConstantExpr::getSizeOf(const Type* Ty) {
1350   // sizeof is implemented as: (i64) gep (Ty*)null, 1
1351   // Note that a non-inbounds gep is used, as null isn't within any object.
1352   Constant *GEPIdx = ConstantInt::get(Type::Int32Ty, 1);
1353   Constant *GEP = getGetElementPtr(
1354                  Constant::getNullValue(PointerType::getUnqual(Ty)), &GEPIdx, 1);
1355   return getCast(Instruction::PtrToInt, GEP, Type::Int64Ty);
1356 }
1357
1358 Constant* ConstantExpr::getAlignOf(const Type* Ty) {
1359   // alignof is implemented as: (i64) gep ({i8,Ty}*)null, 0, 1
1360   const Type *AligningTy = StructType::get(Ty->getContext(),
1361                                            Type::Int8Ty, Ty, NULL);
1362   Constant *NullPtr = Constant::getNullValue(AligningTy->getPointerTo());
1363   Constant *Zero = ConstantInt::get(Type::Int32Ty, 0);
1364   Constant *One = ConstantInt::get(Type::Int32Ty, 1);
1365   Constant *Indices[2] = { Zero, One };
1366   Constant *GEP = getGetElementPtr(NullPtr, Indices, 2);
1367   return getCast(Instruction::PtrToInt, GEP, Type::Int32Ty);
1368 }
1369
1370
1371 Constant *ConstantExpr::getCompare(unsigned short pred,
1372                             Constant *C1, Constant *C2) {
1373   assert(C1->getType() == C2->getType() && "Op types should be identical!");
1374   return getCompareTy(pred, C1, C2);
1375 }
1376
1377 Constant *ConstantExpr::getSelectTy(const Type *ReqTy, Constant *C,
1378                                     Constant *V1, Constant *V2) {
1379   assert(!SelectInst::areInvalidOperands(C, V1, V2)&&"Invalid select operands");
1380
1381   if (ReqTy == V1->getType())
1382     if (Constant *SC = ConstantFoldSelectInstruction(
1383                                                 ReqTy->getContext(), C, V1, V2))
1384       return SC;        // Fold common cases
1385
1386   std::vector<Constant*> argVec(3, C);
1387   argVec[1] = V1;
1388   argVec[2] = V2;
1389   ExprMapKeyType Key(Instruction::Select, argVec);
1390
1391   LLVMContextImpl *pImpl = ReqTy->getContext().pImpl;
1392
1393   // Implicitly locked.
1394   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1395 }
1396
1397 Constant *ConstantExpr::getGetElementPtrTy(const Type *ReqTy, Constant *C,
1398                                            Value* const *Idxs,
1399                                            unsigned NumIdx) {
1400   assert(GetElementPtrInst::getIndexedType(C->getType(), Idxs,
1401                                            Idxs+NumIdx) ==
1402          cast<PointerType>(ReqTy)->getElementType() &&
1403          "GEP indices invalid!");
1404
1405   if (Constant *FC = ConstantFoldGetElementPtr(
1406                               ReqTy->getContext(), C, (Constant**)Idxs, NumIdx))
1407     return FC;          // Fold a few common cases...
1408
1409   assert(isa<PointerType>(C->getType()) &&
1410          "Non-pointer type for constant GetElementPtr expression");
1411   // Look up the constant in the table first to ensure uniqueness
1412   std::vector<Constant*> ArgVec;
1413   ArgVec.reserve(NumIdx+1);
1414   ArgVec.push_back(C);
1415   for (unsigned i = 0; i != NumIdx; ++i)
1416     ArgVec.push_back(cast<Constant>(Idxs[i]));
1417   const ExprMapKeyType Key(Instruction::GetElementPtr, ArgVec);
1418
1419   LLVMContextImpl *pImpl = ReqTy->getContext().pImpl;
1420
1421   // Implicitly locked.
1422   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1423 }
1424
1425 Constant *ConstantExpr::getGetElementPtr(Constant *C, Value* const *Idxs,
1426                                          unsigned NumIdx) {
1427   // Get the result type of the getelementptr!
1428   const Type *Ty =
1429     GetElementPtrInst::getIndexedType(C->getType(), Idxs, Idxs+NumIdx);
1430   assert(Ty && "GEP indices invalid!");
1431   unsigned As = cast<PointerType>(C->getType())->getAddressSpace();
1432   return getGetElementPtrTy(PointerType::get(Ty, As), C, Idxs, NumIdx);
1433 }
1434
1435 Constant *ConstantExpr::getGetElementPtr(Constant *C, Constant* const *Idxs,
1436                                          unsigned NumIdx) {
1437   return getGetElementPtr(C, (Value* const *)Idxs, NumIdx);
1438 }
1439
1440
1441 Constant *
1442 ConstantExpr::getICmp(unsigned short pred, Constant* LHS, Constant* RHS) {
1443   assert(LHS->getType() == RHS->getType());
1444   assert(pred >= ICmpInst::FIRST_ICMP_PREDICATE &&
1445          pred <= ICmpInst::LAST_ICMP_PREDICATE && "Invalid ICmp Predicate");
1446
1447   if (Constant *FC = ConstantFoldCompareInstruction(
1448                                              LHS->getContext(), pred, LHS, RHS))
1449     return FC;          // Fold a few common cases...
1450
1451   // Look up the constant in the table first to ensure uniqueness
1452   std::vector<Constant*> ArgVec;
1453   ArgVec.push_back(LHS);
1454   ArgVec.push_back(RHS);
1455   // Get the key type with both the opcode and predicate
1456   const ExprMapKeyType Key(Instruction::ICmp, ArgVec, pred);
1457
1458   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
1459
1460   // Implicitly locked.
1461   return pImpl->ExprConstants.getOrCreate(Type::Int1Ty, Key);
1462 }
1463
1464 Constant *
1465 ConstantExpr::getFCmp(unsigned short pred, Constant* LHS, Constant* RHS) {
1466   assert(LHS->getType() == RHS->getType());
1467   assert(pred <= FCmpInst::LAST_FCMP_PREDICATE && "Invalid FCmp Predicate");
1468
1469   if (Constant *FC = ConstantFoldCompareInstruction(
1470                                             LHS->getContext(), pred, LHS, RHS))
1471     return FC;          // Fold a few common cases...
1472
1473   // Look up the constant in the table first to ensure uniqueness
1474   std::vector<Constant*> ArgVec;
1475   ArgVec.push_back(LHS);
1476   ArgVec.push_back(RHS);
1477   // Get the key type with both the opcode and predicate
1478   const ExprMapKeyType Key(Instruction::FCmp, ArgVec, pred);
1479
1480   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
1481
1482   // Implicitly locked.
1483   return pImpl->ExprConstants.getOrCreate(Type::Int1Ty, Key);
1484 }
1485
1486 Constant *ConstantExpr::getExtractElementTy(const Type *ReqTy, Constant *Val,
1487                                             Constant *Idx) {
1488   if (Constant *FC = ConstantFoldExtractElementInstruction(
1489                                                 ReqTy->getContext(), Val, Idx))
1490     return FC;          // Fold a few common cases...
1491   // Look up the constant in the table first to ensure uniqueness
1492   std::vector<Constant*> ArgVec(1, Val);
1493   ArgVec.push_back(Idx);
1494   const ExprMapKeyType Key(Instruction::ExtractElement,ArgVec);
1495
1496   LLVMContextImpl *pImpl = ReqTy->getContext().pImpl;
1497
1498   // Implicitly locked.
1499   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1500 }
1501
1502 Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx) {
1503   assert(isa<VectorType>(Val->getType()) &&
1504          "Tried to create extractelement operation on non-vector type!");
1505   assert(Idx->getType() == Type::Int32Ty &&
1506          "Extractelement index must be i32 type!");
1507   return getExtractElementTy(cast<VectorType>(Val->getType())->getElementType(),
1508                              Val, Idx);
1509 }
1510
1511 Constant *ConstantExpr::getInsertElementTy(const Type *ReqTy, Constant *Val,
1512                                            Constant *Elt, Constant *Idx) {
1513   if (Constant *FC = ConstantFoldInsertElementInstruction(
1514                                             ReqTy->getContext(), Val, Elt, Idx))
1515     return FC;          // Fold a few common cases...
1516   // Look up the constant in the table first to ensure uniqueness
1517   std::vector<Constant*> ArgVec(1, Val);
1518   ArgVec.push_back(Elt);
1519   ArgVec.push_back(Idx);
1520   const ExprMapKeyType Key(Instruction::InsertElement,ArgVec);
1521
1522   LLVMContextImpl *pImpl = ReqTy->getContext().pImpl;
1523
1524   // Implicitly locked.
1525   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1526 }
1527
1528 Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
1529                                          Constant *Idx) {
1530   assert(isa<VectorType>(Val->getType()) &&
1531          "Tried to create insertelement operation on non-vector type!");
1532   assert(Elt->getType() == cast<VectorType>(Val->getType())->getElementType()
1533          && "Insertelement types must match!");
1534   assert(Idx->getType() == Type::Int32Ty &&
1535          "Insertelement index must be i32 type!");
1536   return getInsertElementTy(Val->getType(), Val, Elt, Idx);
1537 }
1538
1539 Constant *ConstantExpr::getShuffleVectorTy(const Type *ReqTy, Constant *V1,
1540                                            Constant *V2, Constant *Mask) {
1541   if (Constant *FC = ConstantFoldShuffleVectorInstruction(
1542                                             ReqTy->getContext(), V1, V2, Mask))
1543     return FC;          // Fold a few common cases...
1544   // Look up the constant in the table first to ensure uniqueness
1545   std::vector<Constant*> ArgVec(1, V1);
1546   ArgVec.push_back(V2);
1547   ArgVec.push_back(Mask);
1548   const ExprMapKeyType Key(Instruction::ShuffleVector,ArgVec);
1549
1550   LLVMContextImpl *pImpl = ReqTy->getContext().pImpl;
1551
1552   // Implicitly locked.
1553   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1554 }
1555
1556 Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
1557                                          Constant *Mask) {
1558   assert(ShuffleVectorInst::isValidOperands(V1, V2, Mask) &&
1559          "Invalid shuffle vector constant expr operands!");
1560
1561   unsigned NElts = cast<VectorType>(Mask->getType())->getNumElements();
1562   const Type *EltTy = cast<VectorType>(V1->getType())->getElementType();
1563   const Type *ShufTy = VectorType::get(EltTy, NElts);
1564   return getShuffleVectorTy(ShufTy, V1, V2, Mask);
1565 }
1566
1567 Constant *ConstantExpr::getInsertValueTy(const Type *ReqTy, Constant *Agg,
1568                                          Constant *Val,
1569                                         const unsigned *Idxs, unsigned NumIdx) {
1570   assert(ExtractValueInst::getIndexedType(Agg->getType(), Idxs,
1571                                           Idxs+NumIdx) == Val->getType() &&
1572          "insertvalue indices invalid!");
1573   assert(Agg->getType() == ReqTy &&
1574          "insertvalue type invalid!");
1575   assert(Agg->getType()->isFirstClassType() &&
1576          "Non-first-class type for constant InsertValue expression");
1577   Constant *FC = ConstantFoldInsertValueInstruction(
1578                                   ReqTy->getContext(), Agg, Val, Idxs, NumIdx);
1579   assert(FC && "InsertValue constant expr couldn't be folded!");
1580   return FC;
1581 }
1582
1583 Constant *ConstantExpr::getInsertValue(Constant *Agg, Constant *Val,
1584                                      const unsigned *IdxList, unsigned NumIdx) {
1585   assert(Agg->getType()->isFirstClassType() &&
1586          "Tried to create insertelement operation on non-first-class type!");
1587
1588   const Type *ReqTy = Agg->getType();
1589 #ifndef NDEBUG
1590   const Type *ValTy =
1591     ExtractValueInst::getIndexedType(Agg->getType(), IdxList, IdxList+NumIdx);
1592 #endif
1593   assert(ValTy == Val->getType() && "insertvalue indices invalid!");
1594   return getInsertValueTy(ReqTy, Agg, Val, IdxList, NumIdx);
1595 }
1596
1597 Constant *ConstantExpr::getExtractValueTy(const Type *ReqTy, Constant *Agg,
1598                                         const unsigned *Idxs, unsigned NumIdx) {
1599   assert(ExtractValueInst::getIndexedType(Agg->getType(), Idxs,
1600                                           Idxs+NumIdx) == ReqTy &&
1601          "extractvalue indices invalid!");
1602   assert(Agg->getType()->isFirstClassType() &&
1603          "Non-first-class type for constant extractvalue expression");
1604   Constant *FC = ConstantFoldExtractValueInstruction(
1605                                         ReqTy->getContext(), Agg, Idxs, NumIdx);
1606   assert(FC && "ExtractValue constant expr couldn't be folded!");
1607   return FC;
1608 }
1609
1610 Constant *ConstantExpr::getExtractValue(Constant *Agg,
1611                                      const unsigned *IdxList, unsigned NumIdx) {
1612   assert(Agg->getType()->isFirstClassType() &&
1613          "Tried to create extractelement operation on non-first-class type!");
1614
1615   const Type *ReqTy =
1616     ExtractValueInst::getIndexedType(Agg->getType(), IdxList, IdxList+NumIdx);
1617   assert(ReqTy && "extractvalue indices invalid!");
1618   return getExtractValueTy(ReqTy, Agg, IdxList, NumIdx);
1619 }
1620
1621 Constant* ConstantExpr::getNeg(Constant* C) {
1622   // API compatibility: Adjust integer opcodes to floating-point opcodes.
1623   if (C->getType()->isFPOrFPVector())
1624     return getFNeg(C);
1625   assert(C->getType()->isIntOrIntVector() &&
1626          "Cannot NEG a nonintegral value!");
1627   return get(Instruction::Sub,
1628              ConstantFP::getZeroValueForNegation(C->getType()),
1629              C);
1630 }
1631
1632 Constant* ConstantExpr::getFNeg(Constant* C) {
1633   assert(C->getType()->isFPOrFPVector() &&
1634          "Cannot FNEG a non-floating-point value!");
1635   return get(Instruction::FSub,
1636              ConstantFP::getZeroValueForNegation(C->getType()),
1637              C);
1638 }
1639
1640 Constant* ConstantExpr::getNot(Constant* C) {
1641   assert(C->getType()->isIntOrIntVector() &&
1642          "Cannot NOT a nonintegral value!");
1643   return get(Instruction::Xor, C, Constant::getAllOnesValue(C->getType()));
1644 }
1645
1646 Constant* ConstantExpr::getAdd(Constant* C1, Constant* C2) {
1647   return get(Instruction::Add, C1, C2);
1648 }
1649
1650 Constant* ConstantExpr::getFAdd(Constant* C1, Constant* C2) {
1651   return get(Instruction::FAdd, C1, C2);
1652 }
1653
1654 Constant* ConstantExpr::getSub(Constant* C1, Constant* C2) {
1655   return get(Instruction::Sub, C1, C2);
1656 }
1657
1658 Constant* ConstantExpr::getFSub(Constant* C1, Constant* C2) {
1659   return get(Instruction::FSub, C1, C2);
1660 }
1661
1662 Constant* ConstantExpr::getMul(Constant* C1, Constant* C2) {
1663   return get(Instruction::Mul, C1, C2);
1664 }
1665
1666 Constant* ConstantExpr::getFMul(Constant* C1, Constant* C2) {
1667   return get(Instruction::FMul, C1, C2);
1668 }
1669
1670 Constant* ConstantExpr::getUDiv(Constant* C1, Constant* C2) {
1671   return get(Instruction::UDiv, C1, C2);
1672 }
1673
1674 Constant* ConstantExpr::getSDiv(Constant* C1, Constant* C2) {
1675   return get(Instruction::SDiv, C1, C2);
1676 }
1677
1678 Constant* ConstantExpr::getFDiv(Constant* C1, Constant* C2) {
1679   return get(Instruction::FDiv, C1, C2);
1680 }
1681
1682 Constant* ConstantExpr::getURem(Constant* C1, Constant* C2) {
1683   return get(Instruction::URem, C1, C2);
1684 }
1685
1686 Constant* ConstantExpr::getSRem(Constant* C1, Constant* C2) {
1687   return get(Instruction::SRem, C1, C2);
1688 }
1689
1690 Constant* ConstantExpr::getFRem(Constant* C1, Constant* C2) {
1691   return get(Instruction::FRem, C1, C2);
1692 }
1693
1694 Constant* ConstantExpr::getAnd(Constant* C1, Constant* C2) {
1695   return get(Instruction::And, C1, C2);
1696 }
1697
1698 Constant* ConstantExpr::getOr(Constant* C1, Constant* C2) {
1699   return get(Instruction::Or, C1, C2);
1700 }
1701
1702 Constant* ConstantExpr::getXor(Constant* C1, Constant* C2) {
1703   return get(Instruction::Xor, C1, C2);
1704 }
1705
1706 Constant* ConstantExpr::getShl(Constant* C1, Constant* C2) {
1707   return get(Instruction::Shl, C1, C2);
1708 }
1709
1710 Constant* ConstantExpr::getLShr(Constant* C1, Constant* C2) {
1711   return get(Instruction::LShr, C1, C2);
1712 }
1713
1714 Constant* ConstantExpr::getAShr(Constant* C1, Constant* C2) {
1715   return get(Instruction::AShr, C1, C2);
1716 }
1717
1718 // destroyConstant - Remove the constant from the constant table...
1719 //
1720 void ConstantExpr::destroyConstant() {
1721   // Implicitly locked.
1722   LLVMContextImpl *pImpl = getType()->getContext().pImpl;
1723   pImpl->ExprConstants.remove(this);
1724   destroyConstantImpl();
1725 }
1726
1727 const char *ConstantExpr::getOpcodeName() const {
1728   return Instruction::getOpcodeName(getOpcode());
1729 }
1730
1731 //===----------------------------------------------------------------------===//
1732 //                replaceUsesOfWithOnConstant implementations
1733
1734 /// replaceUsesOfWithOnConstant - Update this constant array to change uses of
1735 /// 'From' to be uses of 'To'.  This must update the uniquing data structures
1736 /// etc.
1737 ///
1738 /// Note that we intentionally replace all uses of From with To here.  Consider
1739 /// a large array that uses 'From' 1000 times.  By handling this case all here,
1740 /// ConstantArray::replaceUsesOfWithOnConstant is only invoked once, and that
1741 /// single invocation handles all 1000 uses.  Handling them one at a time would
1742 /// work, but would be really slow because it would have to unique each updated
1743 /// array instance.
1744
1745 static std::vector<Constant*> getValType(ConstantArray *CA) {
1746   std::vector<Constant*> Elements;
1747   Elements.reserve(CA->getNumOperands());
1748   for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1749     Elements.push_back(cast<Constant>(CA->getOperand(i)));
1750   return Elements;
1751 }
1752
1753
1754 void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To,
1755                                                 Use *U) {
1756   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
1757   Constant *ToC = cast<Constant>(To);
1758
1759   LLVMContext &Context = getType()->getContext();
1760   LLVMContextImpl *pImpl = Context.pImpl;
1761
1762   std::pair<LLVMContextImpl::ArrayConstantsTy::MapKey, Constant*> Lookup;
1763   Lookup.first.first = getType();
1764   Lookup.second = this;
1765
1766   std::vector<Constant*> &Values = Lookup.first.second;
1767   Values.reserve(getNumOperands());  // Build replacement array.
1768
1769   // Fill values with the modified operands of the constant array.  Also,
1770   // compute whether this turns into an all-zeros array.
1771   bool isAllZeros = false;
1772   unsigned NumUpdated = 0;
1773   if (!ToC->isNullValue()) {
1774     for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
1775       Constant *Val = cast<Constant>(O->get());
1776       if (Val == From) {
1777         Val = ToC;
1778         ++NumUpdated;
1779       }
1780       Values.push_back(Val);
1781     }
1782   } else {
1783     isAllZeros = true;
1784     for (Use *O = OperandList, *E = OperandList+getNumOperands();O != E; ++O) {
1785       Constant *Val = cast<Constant>(O->get());
1786       if (Val == From) {
1787         Val = ToC;
1788         ++NumUpdated;
1789       }
1790       Values.push_back(Val);
1791       if (isAllZeros) isAllZeros = Val->isNullValue();
1792     }
1793   }
1794
1795   Constant *Replacement = 0;
1796   if (isAllZeros) {
1797     Replacement = ConstantAggregateZero::get(getType());
1798   } else {
1799     // Check to see if we have this array type already.
1800     sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
1801     bool Exists;
1802     LLVMContextImpl::ArrayConstantsTy::MapTy::iterator I =
1803       pImpl->ArrayConstants.InsertOrGetItem(Lookup, Exists);
1804
1805     if (Exists) {
1806       Replacement = I->second;
1807     } else {
1808       // Okay, the new shape doesn't exist in the system yet.  Instead of
1809       // creating a new constant array, inserting it, replaceallusesof'ing the
1810       // old with the new, then deleting the old... just update the current one
1811       // in place!
1812       pImpl->ArrayConstants.MoveConstantToNewSlot(this, I);
1813
1814       // Update to the new value.  Optimize for the case when we have a single
1815       // operand that we're changing, but handle bulk updates efficiently.
1816       if (NumUpdated == 1) {
1817         unsigned OperandToUpdate = U - OperandList;
1818         assert(getOperand(OperandToUpdate) == From &&
1819                "ReplaceAllUsesWith broken!");
1820         setOperand(OperandToUpdate, ToC);
1821       } else {
1822         for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
1823           if (getOperand(i) == From)
1824             setOperand(i, ToC);
1825       }
1826       return;
1827     }
1828   }
1829
1830   // Otherwise, I do need to replace this with an existing value.
1831   assert(Replacement != this && "I didn't contain From!");
1832
1833   // Everyone using this now uses the replacement.
1834   uncheckedReplaceAllUsesWith(Replacement);
1835
1836   // Delete the old constant!
1837   destroyConstant();
1838 }
1839
1840 static std::vector<Constant*> getValType(ConstantStruct *CS) {
1841   std::vector<Constant*> Elements;
1842   Elements.reserve(CS->getNumOperands());
1843   for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i)
1844     Elements.push_back(cast<Constant>(CS->getOperand(i)));
1845   return Elements;
1846 }
1847
1848 void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
1849                                                  Use *U) {
1850   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
1851   Constant *ToC = cast<Constant>(To);
1852
1853   unsigned OperandToUpdate = U-OperandList;
1854   assert(getOperand(OperandToUpdate) == From && "ReplaceAllUsesWith broken!");
1855
1856   std::pair<LLVMContextImpl::StructConstantsTy::MapKey, Constant*> Lookup;
1857   Lookup.first.first = getType();
1858   Lookup.second = this;
1859   std::vector<Constant*> &Values = Lookup.first.second;
1860   Values.reserve(getNumOperands());  // Build replacement struct.
1861
1862
1863   // Fill values with the modified operands of the constant struct.  Also,
1864   // compute whether this turns into an all-zeros struct.
1865   bool isAllZeros = false;
1866   if (!ToC->isNullValue()) {
1867     for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O)
1868       Values.push_back(cast<Constant>(O->get()));
1869   } else {
1870     isAllZeros = true;
1871     for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
1872       Constant *Val = cast<Constant>(O->get());
1873       Values.push_back(Val);
1874       if (isAllZeros) isAllZeros = Val->isNullValue();
1875     }
1876   }
1877   Values[OperandToUpdate] = ToC;
1878
1879   LLVMContext &Context = getType()->getContext();
1880   LLVMContextImpl *pImpl = Context.pImpl;
1881
1882   Constant *Replacement = 0;
1883   if (isAllZeros) {
1884     Replacement = ConstantAggregateZero::get(getType());
1885   } else {
1886     // Check to see if we have this array type already.
1887     sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
1888     bool Exists;
1889     LLVMContextImpl::StructConstantsTy::MapTy::iterator I =
1890       pImpl->StructConstants.InsertOrGetItem(Lookup, Exists);
1891
1892     if (Exists) {
1893       Replacement = I->second;
1894     } else {
1895       // Okay, the new shape doesn't exist in the system yet.  Instead of
1896       // creating a new constant struct, inserting it, replaceallusesof'ing the
1897       // old with the new, then deleting the old... just update the current one
1898       // in place!
1899       pImpl->StructConstants.MoveConstantToNewSlot(this, I);
1900
1901       // Update to the new value.
1902       setOperand(OperandToUpdate, ToC);
1903       return;
1904     }
1905   }
1906
1907   assert(Replacement != this && "I didn't contain From!");
1908
1909   // Everyone using this now uses the replacement.
1910   uncheckedReplaceAllUsesWith(Replacement);
1911
1912   // Delete the old constant!
1913   destroyConstant();
1914 }
1915
1916 static std::vector<Constant*> getValType(ConstantVector *CP) {
1917   std::vector<Constant*> Elements;
1918   Elements.reserve(CP->getNumOperands());
1919   for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
1920     Elements.push_back(CP->getOperand(i));
1921   return Elements;
1922 }
1923
1924 void ConstantVector::replaceUsesOfWithOnConstant(Value *From, Value *To,
1925                                                  Use *U) {
1926   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
1927
1928   std::vector<Constant*> Values;
1929   Values.reserve(getNumOperands());  // Build replacement array...
1930   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1931     Constant *Val = getOperand(i);
1932     if (Val == From) Val = cast<Constant>(To);
1933     Values.push_back(Val);
1934   }
1935
1936   Constant *Replacement = get(getType(), Values);
1937   assert(Replacement != this && "I didn't contain From!");
1938
1939   // Everyone using this now uses the replacement.
1940   uncheckedReplaceAllUsesWith(Replacement);
1941
1942   // Delete the old constant!
1943   destroyConstant();
1944 }
1945
1946 void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *ToV,
1947                                                Use *U) {
1948   assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
1949   Constant *To = cast<Constant>(ToV);
1950
1951   Constant *Replacement = 0;
1952   if (getOpcode() == Instruction::GetElementPtr) {
1953     SmallVector<Constant*, 8> Indices;
1954     Constant *Pointer = getOperand(0);
1955     Indices.reserve(getNumOperands()-1);
1956     if (Pointer == From) Pointer = To;
1957
1958     for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
1959       Constant *Val = getOperand(i);
1960       if (Val == From) Val = To;
1961       Indices.push_back(Val);
1962     }
1963     Replacement = ConstantExpr::getGetElementPtr(Pointer,
1964                                                  &Indices[0], Indices.size());
1965   } else if (getOpcode() == Instruction::ExtractValue) {
1966     Constant *Agg = getOperand(0);
1967     if (Agg == From) Agg = To;
1968
1969     const SmallVector<unsigned, 4> &Indices = getIndices();
1970     Replacement = ConstantExpr::getExtractValue(Agg,
1971                                                 &Indices[0], Indices.size());
1972   } else if (getOpcode() == Instruction::InsertValue) {
1973     Constant *Agg = getOperand(0);
1974     Constant *Val = getOperand(1);
1975     if (Agg == From) Agg = To;
1976     if (Val == From) Val = To;
1977
1978     const SmallVector<unsigned, 4> &Indices = getIndices();
1979     Replacement = ConstantExpr::getInsertValue(Agg, Val,
1980                                                &Indices[0], Indices.size());
1981   } else if (isCast()) {
1982     assert(getOperand(0) == From && "Cast only has one use!");
1983     Replacement = ConstantExpr::getCast(getOpcode(), To, getType());
1984   } else if (getOpcode() == Instruction::Select) {
1985     Constant *C1 = getOperand(0);
1986     Constant *C2 = getOperand(1);
1987     Constant *C3 = getOperand(2);
1988     if (C1 == From) C1 = To;
1989     if (C2 == From) C2 = To;
1990     if (C3 == From) C3 = To;
1991     Replacement = ConstantExpr::getSelect(C1, C2, C3);
1992   } else if (getOpcode() == Instruction::ExtractElement) {
1993     Constant *C1 = getOperand(0);
1994     Constant *C2 = getOperand(1);
1995     if (C1 == From) C1 = To;
1996     if (C2 == From) C2 = To;
1997     Replacement = ConstantExpr::getExtractElement(C1, C2);
1998   } else if (getOpcode() == Instruction::InsertElement) {
1999     Constant *C1 = getOperand(0);
2000     Constant *C2 = getOperand(1);
2001     Constant *C3 = getOperand(1);
2002     if (C1 == From) C1 = To;
2003     if (C2 == From) C2 = To;
2004     if (C3 == From) C3 = To;
2005     Replacement = ConstantExpr::getInsertElement(C1, C2, C3);
2006   } else if (getOpcode() == Instruction::ShuffleVector) {
2007     Constant *C1 = getOperand(0);
2008     Constant *C2 = getOperand(1);
2009     Constant *C3 = getOperand(2);
2010     if (C1 == From) C1 = To;
2011     if (C2 == From) C2 = To;
2012     if (C3 == From) C3 = To;
2013     Replacement = ConstantExpr::getShuffleVector(C1, C2, C3);
2014   } else if (isCompare()) {
2015     Constant *C1 = getOperand(0);
2016     Constant *C2 = getOperand(1);
2017     if (C1 == From) C1 = To;
2018     if (C2 == From) C2 = To;
2019     if (getOpcode() == Instruction::ICmp)
2020       Replacement = ConstantExpr::getICmp(getPredicate(), C1, C2);
2021     else {
2022       assert(getOpcode() == Instruction::FCmp);
2023       Replacement = ConstantExpr::getFCmp(getPredicate(), C1, C2);
2024     }
2025   } else if (getNumOperands() == 2) {
2026     Constant *C1 = getOperand(0);
2027     Constant *C2 = getOperand(1);
2028     if (C1 == From) C1 = To;
2029     if (C2 == From) C2 = To;
2030     Replacement = ConstantExpr::get(getOpcode(), C1, C2);
2031   } else {
2032     llvm_unreachable("Unknown ConstantExpr type!");
2033     return;
2034   }
2035
2036   assert(Replacement != this && "I didn't contain From!");
2037
2038   // Everyone using this now uses the replacement.
2039   uncheckedReplaceAllUsesWith(Replacement);
2040
2041   // Delete the old constant!
2042   destroyConstant();
2043 }
2044