lib/IR/Constants.cpp

   1 //===-- Constants.cpp - Implement Constant nodes --------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the Constant* classes.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/IR/Constants.h"
  14 #include "ConstantFold.h"
  15 #include "LLVMContextImpl.h"
  16 #include "llvm/ADT/STLExtras.h"
  17 #include "llvm/ADT/SmallVector.h"
  18 #include "llvm/ADT/StringMap.h"
  19 #include "llvm/IR/DerivedTypes.h"
  20 #include "llvm/IR/GetElementPtrTypeIterator.h"
  21 #include "llvm/IR/GlobalValue.h"
  22 #include "llvm/IR/Instructions.h"
  23 #include "llvm/IR/Module.h"
  24 #include "llvm/IR/Operator.h"
  25 #include "llvm/Support/Debug.h"
  26 #include "llvm/Support/ErrorHandling.h"
  27 #include "llvm/Support/ManagedStatic.h"
  28 #include "llvm/Support/MathExtras.h"
  29 #include "llvm/Support/raw_ostream.h"
  30 #include <algorithm>
  31
  32 using namespace llvm;
  33
  34 //===----------------------------------------------------------------------===//
  35 //                              Constant Class
  36 //===----------------------------------------------------------------------===//
  37
  38 bool Constant::isNegativeZeroValue() const {
  39   // Floating point values have an explicit -0.0 value.
  40   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
  41     return CFP->isZero() && CFP->isNegative();
  42
  43   // Equivalent for a vector of -0.0's.
  44   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
  45     if (CV->getElementType()->isFloatingPointTy() && CV->isSplat())
  46       if (CV->getElementAsAPFloat(0).isNegZero())
  47         return true;
  48
  49   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
  50     if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
  51       if (SplatCFP && SplatCFP->isZero() && SplatCFP->isNegative())
  52         return true;
  53
  54   // We've already handled true FP case; any other FP vectors can't represent -0.0.
  55   if (getType()->isFPOrFPVectorTy())
  56     return false;
  57
  58   // Otherwise, just use +0.0.
  59   return isNullValue();
  60 }
  61
  62 // Return true iff this constant is positive zero (floating point), negative
  63 // zero (floating point), or a null value.
  64 bool Constant::isZeroValue() const {
  65   // Floating point values have an explicit -0.0 value.
  66   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
  67     return CFP->isZero();
  68
  69   // Equivalent for a vector of -0.0's.
  70   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
  71     if (CV->getElementType()->isFloatingPointTy() && CV->isSplat())
  72       if (CV->getElementAsAPFloat(0).isZero())
  73         return true;
  74
  75   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
  76     if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
  77       if (SplatCFP && SplatCFP->isZero())
  78         return true;
  79
  80   // Otherwise, just use +0.0.
  81   return isNullValue();
  82 }
  83
  84 bool Constant::isNullValue() const {
  85   // 0 is null.
  86   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
  87     return CI->isZero();
  88
  89   // +0.0 is null.
  90   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
  91     return CFP->isZero() && !CFP->isNegative();
  92
  93   // constant zero is zero for aggregates, cpnull is null for pointers, none for
  94   // tokens.
  95   return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this) ||
  96          isa<ConstantTokenNone>(this);
  97 }
  98
  99 bool Constant::isAllOnesValue() const {
 100   // Check for -1 integers
 101   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 102     return CI->isMinusOne();
 103
 104   // Check for FP which are bitcasted from -1 integers
 105   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 106     return CFP->getValueAPF().bitcastToAPInt().isAllOnesValue();
 107
 108   // Check for constant vectors which are splats of -1 values.
 109   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
 110     if (Constant *Splat = CV->getSplatValue())
 111       return Splat->isAllOnesValue();
 112
 113   // Check for constant vectors which are splats of -1 values.
 114   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this)) {
 115     if (CV->isSplat()) {
 116       if (CV->getElementType()->isFloatingPointTy())
 117         return CV->getElementAsAPFloat(0).bitcastToAPInt().isAllOnesValue();
 118       return CV->getElementAsAPInt(0).isAllOnesValue();
 119     }
 120   }
 121
 122   return false;
 123 }
 124
 125 bool Constant::isOneValue() const {
 126   // Check for 1 integers
 127   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 128     return CI->isOne();
 129
 130   // Check for FP which are bitcasted from 1 integers
 131   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 132     return CFP->getValueAPF().bitcastToAPInt().isOneValue();
 133
 134   // Check for constant vectors which are splats of 1 values.
 135   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
 136     if (Constant *Splat = CV->getSplatValue())
 137       return Splat->isOneValue();
 138
 139   // Check for constant vectors which are splats of 1 values.
 140   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this)) {
 141     if (CV->isSplat()) {
 142       if (CV->getElementType()->isFloatingPointTy())
 143         return CV->getElementAsAPFloat(0).bitcastToAPInt().isOneValue();
 144       return CV->getElementAsAPInt(0).isOneValue();
 145     }
 146   }
 147
 148   return false;
 149 }
 150
 151 bool Constant::isMinSignedValue() const {
 152   // Check for INT_MIN integers
 153   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 154     return CI->isMinValue(/*isSigned=*/true);
 155
 156   // Check for FP which are bitcasted from INT_MIN integers
 157   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 158     return CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
 159
 160   // Check for constant vectors which are splats of INT_MIN values.
 161   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
 162     if (Constant *Splat = CV->getSplatValue())
 163       return Splat->isMinSignedValue();
 164
 165   // Check for constant vectors which are splats of INT_MIN values.
 166   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this)) {
 167     if (CV->isSplat()) {
 168       if (CV->getElementType()->isFloatingPointTy())
 169         return CV->getElementAsAPFloat(0).bitcastToAPInt().isMinSignedValue();
 170       return CV->getElementAsAPInt(0).isMinSignedValue();
 171     }
 172   }
 173
 174   return false;
 175 }
 176
 177 bool Constant::isNotMinSignedValue() const {
 178   // Check for INT_MIN integers
 179   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 180     return !CI->isMinValue(/*isSigned=*/true);
 181
 182   // Check for FP which are bitcasted from INT_MIN integers
 183   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 184     return !CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
 185
 186   // Check that vectors don't contain INT_MIN
 187   if (this->getType()->isVectorTy()) {
 188     unsigned NumElts = this->getType()->getVectorNumElements();
 189     for (unsigned i = 0; i != NumElts; ++i) {
 190       Constant *Elt = this->getAggregateElement(i);
 191       if (!Elt || !Elt->isNotMinSignedValue())
 192         return false;
 193     }
 194     return true;
 195   }
 196
 197   // It *may* contain INT_MIN, we can't tell.
 198   return false;
 199 }
 200
 201 bool Constant::isFiniteNonZeroFP() const {
 202   if (auto *CFP = dyn_cast<ConstantFP>(this))
 203     return CFP->getValueAPF().isFiniteNonZero();
 204   if (!getType()->isVectorTy())
 205     return false;
 206   for (unsigned i = 0, e = getType()->getVectorNumElements(); i != e; ++i) {
 207     auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
 208     if (!CFP || !CFP->getValueAPF().isFiniteNonZero())
 209       return false;
 210   }
 211   return true;
 212 }
 213
 214 bool Constant::isNormalFP() const {
 215   if (auto *CFP = dyn_cast<ConstantFP>(this))
 216     return CFP->getValueAPF().isNormal();
 217   if (!getType()->isVectorTy())
 218     return false;
 219   for (unsigned i = 0, e = getType()->getVectorNumElements(); i != e; ++i) {
 220     auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
 221     if (!CFP || !CFP->getValueAPF().isNormal())
 222       return false;
 223   }
 224   return true;
 225 }
 226
 227 bool Constant::hasExactInverseFP() const {
 228   if (auto *CFP = dyn_cast<ConstantFP>(this))
 229     return CFP->getValueAPF().getExactInverse(nullptr);
 230   if (!getType()->isVectorTy())
 231     return false;
 232   for (unsigned i = 0, e = getType()->getVectorNumElements(); i != e; ++i) {
 233     auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
 234     if (!CFP || !CFP->getValueAPF().getExactInverse(nullptr))
 235       return false;
 236   }
 237   return true;
 238 }
 239
 240 bool Constant::isNaN() const {
 241   if (auto *CFP = dyn_cast<ConstantFP>(this))
 242     return CFP->isNaN();
 243   if (!getType()->isVectorTy())
 244     return false;
 245   for (unsigned i = 0, e = getType()->getVectorNumElements(); i != e; ++i) {
 246     auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
 247     if (!CFP || !CFP->isNaN())
 248       return false;
 249   }
 250   return true;
 251 }
 252
 253 bool Constant::containsUndefElement() const {
 254   if (!getType()->isVectorTy())
 255     return false;
 256   for (unsigned i = 0, e = getType()->getVectorNumElements(); i != e; ++i)
 257     if (isa<UndefValue>(getAggregateElement(i)))
 258       return true;
 259
 260   return false;
 261 }
 262
 263 bool Constant::containsConstantExpression() const {
 264   if (!getType()->isVectorTy())
 265     return false;
 266   for (unsigned i = 0, e = getType()->getVectorNumElements(); i != e; ++i)
 267     if (isa<ConstantExpr>(getAggregateElement(i)))
 268       return true;
 269
 270   return false;
 271 }
 272
 273 /// Constructor to create a '0' constant of arbitrary type.
 274 Constant *Constant::getNullValue(Type *Ty) {
 275   switch (Ty->getTypeID()) {
 276   case Type::IntegerTyID:
 277     return ConstantInt::get(Ty, 0);
 278   case Type::HalfTyID:
 279     return ConstantFP::get(Ty->getContext(),
 280                            APFloat::getZero(APFloat::IEEEhalf()));
 281   case Type::FloatTyID:
 282     return ConstantFP::get(Ty->getContext(),
 283                            APFloat::getZero(APFloat::IEEEsingle()));
 284   case Type::DoubleTyID:
 285     return ConstantFP::get(Ty->getContext(),
 286                            APFloat::getZero(APFloat::IEEEdouble()));
 287   case Type::X86_FP80TyID:
 288     return ConstantFP::get(Ty->getContext(),
 289                            APFloat::getZero(APFloat::x87DoubleExtended()));
 290   case Type::FP128TyID:
 291     return ConstantFP::get(Ty->getContext(),
 292                            APFloat::getZero(APFloat::IEEEquad()));
 293   case Type::PPC_FP128TyID:
 294     return ConstantFP::get(Ty->getContext(),
 295                            APFloat(APFloat::PPCDoubleDouble(),
 296                                    APInt::getNullValue(128)));
 297   case Type::PointerTyID:
 298     return ConstantPointerNull::get(cast<PointerType>(Ty));
 299   case Type::StructTyID:
 300   case Type::ArrayTyID:
 301   case Type::VectorTyID:
 302     return ConstantAggregateZero::get(Ty);
 303   case Type::TokenTyID:
 304     return ConstantTokenNone::get(Ty->getContext());
 305   default:
 306     // Function, Label, or Opaque type?
 307     llvm_unreachable("Cannot create a null constant of that type!");
 308   }
 309 }
 310
 311 Constant *Constant::getIntegerValue(Type *Ty, const APInt &V) {
 312   Type *ScalarTy = Ty->getScalarType();
 313
 314   // Create the base integer constant.
 315   Constant *C = ConstantInt::get(Ty->getContext(), V);
 316
 317   // Convert an integer to a pointer, if necessary.
 318   if (PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
 319     C = ConstantExpr::getIntToPtr(C, PTy);
 320
 321   // Broadcast a scalar to a vector, if necessary.
 322   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 323     C = ConstantVector::getSplat(VTy->getNumElements(), C);
 324
 325   return C;
 326 }
 327
 328 Constant *Constant::getAllOnesValue(Type *Ty) {
 329   if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
 330     return ConstantInt::get(Ty->getContext(),
 331                             APInt::getAllOnesValue(ITy->getBitWidth()));
 332
 333   if (Ty->isFloatingPointTy()) {
 334     APFloat FL = APFloat::getAllOnesValue(Ty->getPrimitiveSizeInBits(),
 335                                           !Ty->isPPC_FP128Ty());
 336     return ConstantFP::get(Ty->getContext(), FL);
 337   }
 338
 339   VectorType *VTy = cast<VectorType>(Ty);
 340   return ConstantVector::getSplat(VTy->getNumElements(),
 341                                   getAllOnesValue(VTy->getElementType()));
 342 }
 343
 344 Constant *Constant::getAggregateElement(unsigned Elt) const {
 345   if (const ConstantAggregate *CC = dyn_cast<ConstantAggregate>(this))
 346     return Elt < CC->getNumOperands() ? CC->getOperand(Elt) : nullptr;
 347
 348   if (const ConstantAggregateZero *CAZ = dyn_cast<ConstantAggregateZero>(this))
 349     return Elt < CAZ->getNumElements() ? CAZ->getElementValue(Elt) : nullptr;
 350
 351   if (const UndefValue *UV = dyn_cast<UndefValue>(this))
 352     return Elt < UV->getNumElements() ? UV->getElementValue(Elt) : nullptr;
 353
 354   if (const ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(this))
 355     return Elt < CDS->getNumElements() ? CDS->getElementAsConstant(Elt)
 356                                        : nullptr;
 357   return nullptr;
 358 }
 359
 360 Constant *Constant::getAggregateElement(Constant *Elt) const {
 361   assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer");
 362   if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt)) {
 363     // Check if the constant fits into an uint64_t.
 364     if (CI->getValue().getActiveBits() > 64)
 365       return nullptr;
 366     return getAggregateElement(CI->getZExtValue());
 367   }
 368   return nullptr;
 369 }
 370
 371 void Constant::destroyConstant() {
 372   /// First call destroyConstantImpl on the subclass.  This gives the subclass
 373   /// a chance to remove the constant from any maps/pools it's contained in.
 374   switch (getValueID()) {
 375   default:
 376     llvm_unreachable("Not a constant!");
 377 #define HANDLE_CONSTANT(Name)                                                  \
 378   case Value::Name##Val:                                                       \
 379     cast<Name>(this)->destroyConstantImpl();                                   \
 380     break;
 381 #include "llvm/IR/Value.def"
 382   }
 383
 384   // When a Constant is destroyed, there may be lingering
 385   // references to the constant by other constants in the constant pool.  These
 386   // constants are implicitly dependent on the module that is being deleted,
 387   // but they don't know that.  Because we only find out when the CPV is
 388   // deleted, we must now notify all of our users (that should only be
 389   // Constants) that they are, in fact, invalid now and should be deleted.
 390   //
 391   while (!use_empty()) {
 392     Value *V = user_back();
 393 #ifndef NDEBUG // Only in -g mode...
 394     if (!isa<Constant>(V)) {
 395       dbgs() << "While deleting: " << *this
 396              << "\n\nUse still stuck around after Def is destroyed: " << *V
 397              << "\n\n";
 398     }
 399 #endif
 400     assert(isa<Constant>(V) && "References remain to Constant being destroyed");
 401     cast<Constant>(V)->destroyConstant();
 402
 403     // The constant should remove itself from our use list...
 404     assert((use_empty() || user_back() != V) && "Constant not removed!");
 405   }
 406
 407   // Value has no outstanding references it is safe to delete it now...
 408   delete this;
 409 }
 410
 411 static bool canTrapImpl(const Constant *C,
 412                         SmallPtrSetImpl<const ConstantExpr *> &NonTrappingOps) {
 413   assert(C->getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
 414   // The only thing that could possibly trap are constant exprs.
 415   const ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
 416   if (!CE)
 417     return false;
 418
 419   // ConstantExpr traps if any operands can trap.
 420   for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) {
 421     if (ConstantExpr *Op = dyn_cast<ConstantExpr>(CE->getOperand(i))) {
 422       if (NonTrappingOps.insert(Op).second && canTrapImpl(Op, NonTrappingOps))
 423         return true;
 424     }
 425   }
 426
 427   // Otherwise, only specific operations can trap.
 428   switch (CE->getOpcode()) {
 429   default:
 430     return false;
 431   case Instruction::UDiv:
 432   case Instruction::SDiv:
 433   case Instruction::URem:
 434   case Instruction::SRem:
 435     // Div and rem can trap if the RHS is not known to be non-zero.
 436     if (!isa<ConstantInt>(CE->getOperand(1)) ||CE->getOperand(1)->isNullValue())
 437       return true;
 438     return false;
 439   }
 440 }
 441
 442 bool Constant::canTrap() const {
 443   SmallPtrSet<const ConstantExpr *, 4> NonTrappingOps;
 444   return canTrapImpl(this, NonTrappingOps);
 445 }
 446
 447 /// Check if C contains a GlobalValue for which Predicate is true.
 448 static bool
 449 ConstHasGlobalValuePredicate(const Constant *C,
 450                              bool (*Predicate)(const GlobalValue *)) {
 451   SmallPtrSet<const Constant *, 8> Visited;
 452   SmallVector<const Constant *, 8> WorkList;
 453   WorkList.push_back(C);
 454   Visited.insert(C);
 455
 456   while (!WorkList.empty()) {
 457     const Constant *WorkItem = WorkList.pop_back_val();
 458     if (const auto *GV = dyn_cast<GlobalValue>(WorkItem))
 459       if (Predicate(GV))
 460         return true;
 461     for (const Value *Op : WorkItem->operands()) {
 462       const Constant *ConstOp = dyn_cast<Constant>(Op);
 463       if (!ConstOp)
 464         continue;
 465       if (Visited.insert(ConstOp).second)
 466         WorkList.push_back(ConstOp);
 467     }
 468   }
 469   return false;
 470 }
 471
 472 bool Constant::isThreadDependent() const {
 473   auto DLLImportPredicate = [](const GlobalValue *GV) {
 474     return GV->isThreadLocal();
 475   };
 476   return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
 477 }
 478
 479 bool Constant::isDLLImportDependent() const {
 480   auto DLLImportPredicate = [](const GlobalValue *GV) {
 481     return GV->hasDLLImportStorageClass();
 482   };
 483   return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
 484 }
 485
 486 bool Constant::isConstantUsed() const {
 487   for (const User *U : users()) {
 488     const Constant *UC = dyn_cast<Constant>(U);
 489     if (!UC || isa<GlobalValue>(UC))
 490       return true;
 491
 492     if (UC->isConstantUsed())
 493       return true;
 494   }
 495   return false;
 496 }
 497
 498 bool Constant::needsRelocation() const {
 499   if (isa<GlobalValue>(this))
 500     return true; // Global reference.
 501
 502   if (const BlockAddress *BA = dyn_cast<BlockAddress>(this))
 503     return BA->getFunction()->needsRelocation();
 504
 505   // While raw uses of blockaddress need to be relocated, differences between
 506   // two of them don't when they are for labels in the same function.  This is a
 507   // common idiom when creating a table for the indirect goto extension, so we
 508   // handle it efficiently here.
 509   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(this))
 510     if (CE->getOpcode() == Instruction::Sub) {
 511       ConstantExpr *LHS = dyn_cast<ConstantExpr>(CE->getOperand(0));
 512       ConstantExpr *RHS = dyn_cast<ConstantExpr>(CE->getOperand(1));
 513       if (LHS && RHS && LHS->getOpcode() == Instruction::PtrToInt &&
 514           RHS->getOpcode() == Instruction::PtrToInt &&
 515           isa<BlockAddress>(LHS->getOperand(0)) &&
 516           isa<BlockAddress>(RHS->getOperand(0)) &&
 517           cast<BlockAddress>(LHS->getOperand(0))->getFunction() ==
 518               cast<BlockAddress>(RHS->getOperand(0))->getFunction())
 519         return false;
 520     }
 521
 522   bool Result = false;
 523   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 524     Result |= cast<Constant>(getOperand(i))->needsRelocation();
 525
 526   return Result;
 527 }
 528
 529 /// If the specified constantexpr is dead, remove it. This involves recursively
 530 /// eliminating any dead users of the constantexpr.
 531 static bool removeDeadUsersOfConstant(const Constant *C) {
 532   if (isa<GlobalValue>(C)) return false; // Cannot remove this
 533
 534   while (!C->use_empty()) {
 535     const Constant *User = dyn_cast<Constant>(C->user_back());
 536     if (!User) return false; // Non-constant usage;
 537     if (!removeDeadUsersOfConstant(User))
 538       return false; // Constant wasn't dead
 539   }
 540
 541   const_cast<Constant*>(C)->destroyConstant();
 542   return true;
 543 }
 544
 545
 546 void Constant::removeDeadConstantUsers() const {
 547   Value::const_user_iterator I = user_begin(), E = user_end();
 548   Value::const_user_iterator LastNonDeadUser = E;
 549   while (I != E) {
 550     const Constant *User = dyn_cast<Constant>(*I);
 551     if (!User) {
 552       LastNonDeadUser = I;
 553       ++I;
 554       continue;
 555     }
 556
 557     if (!removeDeadUsersOfConstant(User)) {
 558       // If the constant wasn't dead, remember that this was the last live use
 559       // and move on to the next constant.
 560       LastNonDeadUser = I;
 561       ++I;
 562       continue;
 563     }
 564
 565     // If the constant was dead, then the iterator is invalidated.
 566     if (LastNonDeadUser == E) {
 567       I = user_begin();
 568       if (I == E) break;
 569     } else {
 570       I = LastNonDeadUser;
 571       ++I;
 572     }
 573   }
 574 }
 575
 576
 577
 578 //===----------------------------------------------------------------------===//
 579 //                                ConstantInt
 580 //===----------------------------------------------------------------------===//
 581
 582 ConstantInt::ConstantInt(IntegerType *Ty, const APInt &V)
 583     : ConstantData(Ty, ConstantIntVal), Val(V) {
 584   assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type");
 585 }
 586
 587 ConstantInt *ConstantInt::getTrue(LLVMContext &Context) {
 588   LLVMContextImpl *pImpl = Context.pImpl;
 589   if (!pImpl->TheTrueVal)
 590     pImpl->TheTrueVal = ConstantInt::get(Type::getInt1Ty(Context), 1);
 591   return pImpl->TheTrueVal;
 592 }
 593
 594 ConstantInt *ConstantInt::getFalse(LLVMContext &Context) {
 595   LLVMContextImpl *pImpl = Context.pImpl;
 596   if (!pImpl->TheFalseVal)
 597     pImpl->TheFalseVal = ConstantInt::get(Type::getInt1Ty(Context), 0);
 598   return pImpl->TheFalseVal;
 599 }
 600
 601 Constant *ConstantInt::getTrue(Type *Ty) {
 602   assert(Ty->isIntOrIntVectorTy(1) && "Type not i1 or vector of i1.");
 603   ConstantInt *TrueC = ConstantInt::getTrue(Ty->getContext());
 604   if (auto *VTy = dyn_cast<VectorType>(Ty))
 605     return ConstantVector::getSplat(VTy->getNumElements(), TrueC);
 606   return TrueC;
 607 }
 608
 609 Constant *ConstantInt::getFalse(Type *Ty) {
 610   assert(Ty->isIntOrIntVectorTy(1) && "Type not i1 or vector of i1.");
 611   ConstantInt *FalseC = ConstantInt::getFalse(Ty->getContext());
 612   if (auto *VTy = dyn_cast<VectorType>(Ty))
 613     return ConstantVector::getSplat(VTy->getNumElements(), FalseC);
 614   return FalseC;
 615 }
 616
 617 // Get a ConstantInt from an APInt.
 618 ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) {
 619   // get an existing value or the insertion position
 620   LLVMContextImpl *pImpl = Context.pImpl;
 621   std::unique_ptr<ConstantInt> &Slot = pImpl->IntConstants[V];
 622   if (!Slot) {
 623     // Get the corresponding integer type for the bit width of the value.
 624     IntegerType *ITy = IntegerType::get(Context, V.getBitWidth());
 625     Slot.reset(new ConstantInt(ITy, V));
 626   }
 627   assert(Slot->getType() == IntegerType::get(Context, V.getBitWidth()));
 628   return Slot.get();
 629 }
 630
 631 Constant *ConstantInt::get(Type *Ty, uint64_t V, bool isSigned) {
 632   Constant *C = get(cast<IntegerType>(Ty->getScalarType()), V, isSigned);
 633
 634   // For vectors, broadcast the value.
 635   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 636     return ConstantVector::getSplat(VTy->getNumElements(), C);
 637
 638   return C;
 639 }
 640
 641 ConstantInt *ConstantInt::get(IntegerType *Ty, uint64_t V, bool isSigned) {
 642   return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
 643 }
 644
 645 ConstantInt *ConstantInt::getSigned(IntegerType *Ty, int64_t V) {
 646   return get(Ty, V, true);
 647 }
 648
 649 Constant *ConstantInt::getSigned(Type *Ty, int64_t V) {
 650   return get(Ty, V, true);
 651 }
 652
 653 Constant *ConstantInt::get(Type *Ty, const APInt& V) {
 654   ConstantInt *C = get(Ty->getContext(), V);
 655   assert(C->getType() == Ty->getScalarType() &&
 656          "ConstantInt type doesn't match the type implied by its value!");
 657
 658   // For vectors, broadcast the value.
 659   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 660     return ConstantVector::getSplat(VTy->getNumElements(), C);
 661
 662   return C;
 663 }
 664
 665 ConstantInt *ConstantInt::get(IntegerType* Ty, StringRef Str, uint8_t radix) {
 666   return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix));
 667 }
 668
 669 /// Remove the constant from the constant table.
 670 void ConstantInt::destroyConstantImpl() {
 671   llvm_unreachable("You can't ConstantInt->destroyConstantImpl()!");
 672 }
 673
 674 //===----------------------------------------------------------------------===//
 675 //                                ConstantFP
 676 //===----------------------------------------------------------------------===//
 677
 678 static const fltSemantics *TypeToFloatSemantics(Type *Ty) {
 679   if (Ty->isHalfTy())
 680     return &APFloat::IEEEhalf();
 681   if (Ty->isFloatTy())
 682     return &APFloat::IEEEsingle();
 683   if (Ty->isDoubleTy())
 684     return &APFloat::IEEEdouble();
 685   if (Ty->isX86_FP80Ty())
 686     return &APFloat::x87DoubleExtended();
 687   else if (Ty->isFP128Ty())
 688     return &APFloat::IEEEquad();
 689
 690   assert(Ty->isPPC_FP128Ty() && "Unknown FP format");
 691   return &APFloat::PPCDoubleDouble();
 692 }
 693
 694 Constant *ConstantFP::get(Type *Ty, double V) {
 695   LLVMContext &Context = Ty->getContext();
 696
 697   APFloat FV(V);
 698   bool ignored;
 699   FV.convert(*TypeToFloatSemantics(Ty->getScalarType()),
 700              APFloat::rmNearestTiesToEven, &ignored);
 701   Constant *C = get(Context, FV);
 702
 703   // For vectors, broadcast the value.
 704   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 705     return ConstantVector::getSplat(VTy->getNumElements(), C);
 706
 707   return C;
 708 }
 709
 710 Constant *ConstantFP::get(Type *Ty, const APFloat &V) {
 711   ConstantFP *C = get(Ty->getContext(), V);
 712   assert(C->getType() == Ty->getScalarType() &&
 713          "ConstantFP type doesn't match the type implied by its value!");
 714
 715   // For vectors, broadcast the value.
 716   if (auto *VTy = dyn_cast<VectorType>(Ty))
 717     return ConstantVector::getSplat(VTy->getNumElements(), C);
 718
 719   return C;
 720 }
 721
 722 Constant *ConstantFP::get(Type *Ty, StringRef Str) {
 723   LLVMContext &Context = Ty->getContext();
 724
 725   APFloat FV(*TypeToFloatSemantics(Ty->getScalarType()), Str);
 726   Constant *C = get(Context, FV);
 727
 728   // For vectors, broadcast the value.
 729   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 730     return ConstantVector::getSplat(VTy->getNumElements(), C);
 731
 732   return C;
 733 }
 734
 735 Constant *ConstantFP::getNaN(Type *Ty, bool Negative, uint64_t Payload) {
 736   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
 737   APFloat NaN = APFloat::getNaN(Semantics, Negative, Payload);
 738   Constant *C = get(Ty->getContext(), NaN);
 739
 740   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 741     return ConstantVector::getSplat(VTy->getNumElements(), C);
 742
 743   return C;
 744 }
 745
 746 Constant *ConstantFP::getQNaN(Type *Ty, bool Negative, APInt *Payload) {
 747   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
 748   APFloat NaN = APFloat::getQNaN(Semantics, Negative, Payload);
 749   Constant *C = get(Ty->getContext(), NaN);
 750
 751   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 752     return ConstantVector::getSplat(VTy->getNumElements(), C);
 753
 754   return C;
 755 }
 756
 757 Constant *ConstantFP::getSNaN(Type *Ty, bool Negative, APInt *Payload) {
 758   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
 759   APFloat NaN = APFloat::getSNaN(Semantics, Negative, Payload);
 760   Constant *C = get(Ty->getContext(), NaN);
 761
 762   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 763     return ConstantVector::getSplat(VTy->getNumElements(), C);
 764
 765   return C;
 766 }
 767
 768 Constant *ConstantFP::getNegativeZero(Type *Ty) {
 769   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
 770   APFloat NegZero = APFloat::getZero(Semantics, /*Negative=*/true);
 771   Constant *C = get(Ty->getContext(), NegZero);
 772
 773   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 774     return ConstantVector::getSplat(VTy->getNumElements(), C);
 775
 776   return C;
 777 }
 778
 779
 780 Constant *ConstantFP::getZeroValueForNegation(Type *Ty) {
 781   if (Ty->isFPOrFPVectorTy())
 782     return getNegativeZero(Ty);
 783
 784   return Constant::getNullValue(Ty);
 785 }
 786
 787
 788 // ConstantFP accessors.
 789 ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
 790   LLVMContextImpl* pImpl = Context.pImpl;
 791
 792   std::unique_ptr<ConstantFP> &Slot = pImpl->FPConstants[V];
 793
 794   if (!Slot) {
 795     Type *Ty;
 796     if (&V.getSemantics() == &APFloat::IEEEhalf())
 797       Ty = Type::getHalfTy(Context);
 798     else if (&V.getSemantics() == &APFloat::IEEEsingle())
 799       Ty = Type::getFloatTy(Context);
 800     else if (&V.getSemantics() == &APFloat::IEEEdouble())
 801       Ty = Type::getDoubleTy(Context);
 802     else if (&V.getSemantics() == &APFloat::x87DoubleExtended())
 803       Ty = Type::getX86_FP80Ty(Context);
 804     else if (&V.getSemantics() == &APFloat::IEEEquad())
 805       Ty = Type::getFP128Ty(Context);
 806     else {
 807       assert(&V.getSemantics() == &APFloat::PPCDoubleDouble() &&
 808              "Unknown FP format");
 809       Ty = Type::getPPC_FP128Ty(Context);
 810     }
 811     Slot.reset(new ConstantFP(Ty, V));
 812   }
 813
 814   return Slot.get();
 815 }
 816
 817 Constant *ConstantFP::getInfinity(Type *Ty, bool Negative) {
 818   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
 819   Constant *C = get(Ty->getContext(), APFloat::getInf(Semantics, Negative));
 820
 821   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 822     return ConstantVector::getSplat(VTy->getNumElements(), C);
 823
 824   return C;
 825 }
 826
 827 ConstantFP::ConstantFP(Type *Ty, const APFloat &V)
 828     : ConstantData(Ty, ConstantFPVal), Val(V) {
 829   assert(&V.getSemantics() == TypeToFloatSemantics(Ty) &&
 830          "FP type Mismatch");
 831 }
 832
 833 bool ConstantFP::isExactlyValue(const APFloat &V) const {
 834   return Val.bitwiseIsEqual(V);
 835 }
 836
 837 /// Remove the constant from the constant table.
 838 void ConstantFP::destroyConstantImpl() {
 839   llvm_unreachable("You can't ConstantFP->destroyConstantImpl()!");
 840 }
 841
 842 //===----------------------------------------------------------------------===//
 843 //                   ConstantAggregateZero Implementation
 844 //===----------------------------------------------------------------------===//
 845
 846 Constant *ConstantAggregateZero::getSequentialElement() const {
 847   return Constant::getNullValue(getType()->getSequentialElementType());
 848 }
 849
 850 Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const {
 851   return Constant::getNullValue(getType()->getStructElementType(Elt));
 852 }
 853
 854 Constant *ConstantAggregateZero::getElementValue(Constant *C) const {
 855   if (isa<SequentialType>(getType()))
 856     return getSequentialElement();
 857   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
 858 }
 859
 860 Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const {
 861   if (isa<SequentialType>(getType()))
 862     return getSequentialElement();
 863   return getStructElement(Idx);
 864 }
 865
 866 unsigned ConstantAggregateZero::getNumElements() const {
 867   Type *Ty = getType();
 868   if (auto *AT = dyn_cast<ArrayType>(Ty))
 869     return AT->getNumElements();
 870   if (auto *VT = dyn_cast<VectorType>(Ty))
 871     return VT->getNumElements();
 872   return Ty->getStructNumElements();
 873 }
 874
 875 //===----------------------------------------------------------------------===//
 876 //                         UndefValue Implementation
 877 //===----------------------------------------------------------------------===//
 878
 879 UndefValue *UndefValue::getSequentialElement() const {
 880   return UndefValue::get(getType()->getSequentialElementType());
 881 }
 882
 883 UndefValue *UndefValue::getStructElement(unsigned Elt) const {
 884   return UndefValue::get(getType()->getStructElementType(Elt));
 885 }
 886
 887 UndefValue *UndefValue::getElementValue(Constant *C) const {
 888   if (isa<SequentialType>(getType()))
 889     return getSequentialElement();
 890   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
 891 }
 892
 893 UndefValue *UndefValue::getElementValue(unsigned Idx) const {
 894   if (isa<SequentialType>(getType()))
 895     return getSequentialElement();
 896   return getStructElement(Idx);
 897 }
 898
 899 unsigned UndefValue::getNumElements() const {
 900   Type *Ty = getType();
 901   if (auto *ST = dyn_cast<SequentialType>(Ty))
 902     return ST->getNumElements();
 903   return Ty->getStructNumElements();
 904 }
 905
 906 //===----------------------------------------------------------------------===//
 907 //                            ConstantXXX Classes
 908 //===----------------------------------------------------------------------===//
 909
 910 template <typename ItTy, typename EltTy>
 911 static bool rangeOnlyContains(ItTy Start, ItTy End, EltTy Elt) {
 912   for (; Start != End; ++Start)
 913     if (*Start != Elt)
 914       return false;
 915   return true;
 916 }
 917
 918 template <typename SequentialTy, typename ElementTy>
 919 static Constant *getIntSequenceIfElementsMatch(ArrayRef<Constant *> V) {
 920   assert(!V.empty() && "Cannot get empty int sequence.");
 921
 922   SmallVector<ElementTy, 16> Elts;
 923   for (Constant *C : V)
 924     if (auto *CI = dyn_cast<ConstantInt>(C))
 925       Elts.push_back(CI->getZExtValue());
 926     else
 927       return nullptr;
 928   return SequentialTy::get(V[0]->getContext(), Elts);
 929 }
 930
 931 template <typename SequentialTy, typename ElementTy>
 932 static Constant *getFPSequenceIfElementsMatch(ArrayRef<Constant *> V) {
 933   assert(!V.empty() && "Cannot get empty FP sequence.");
 934
 935   SmallVector<ElementTy, 16> Elts;
 936   for (Constant *C : V)
 937     if (auto *CFP = dyn_cast<ConstantFP>(C))
 938       Elts.push_back(CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
 939     else
 940       return nullptr;
 941   return SequentialTy::getFP(V[0]->getContext(), Elts);
 942 }
 943
 944 template <typename SequenceTy>
 945 static Constant *getSequenceIfElementsMatch(Constant *C,
 946                                             ArrayRef<Constant *> V) {
 947   // We speculatively build the elements here even if it turns out that there is
 948   // a constantexpr or something else weird, since it is so uncommon for that to
 949   // happen.
 950   if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
 951     if (CI->getType()->isIntegerTy(8))
 952       return getIntSequenceIfElementsMatch<SequenceTy, uint8_t>(V);
 953     else if (CI->getType()->isIntegerTy(16))
 954       return getIntSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
 955     else if (CI->getType()->isIntegerTy(32))
 956       return getIntSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
 957     else if (CI->getType()->isIntegerTy(64))
 958       return getIntSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
 959   } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 960     if (CFP->getType()->isHalfTy())
 961       return getFPSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
 962     else if (CFP->getType()->isFloatTy())
 963       return getFPSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
 964     else if (CFP->getType()->isDoubleTy())
 965       return getFPSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
 966   }
 967
 968   return nullptr;
 969 }
 970
 971 ConstantAggregate::ConstantAggregate(CompositeType *T, ValueTy VT,
 972                                      ArrayRef<Constant *> V)
 973     : Constant(T, VT, OperandTraits<ConstantAggregate>::op_end(this) - V.size(),
 974                V.size()) {
 975   llvm::copy(V, op_begin());
 976
 977   // Check that types match, unless this is an opaque struct.
 978   if (auto *ST = dyn_cast<StructType>(T))
 979     if (ST->isOpaque())
 980       return;
 981   for (unsigned I = 0, E = V.size(); I != E; ++I)
 982     assert(V[I]->getType() == T->getTypeAtIndex(I) &&
 983            "Initializer for composite element doesn't match!");
 984 }
 985
 986 ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V)
 987     : ConstantAggregate(T, ConstantArrayVal, V) {
 988   assert(V.size() == T->getNumElements() &&
 989          "Invalid initializer for constant array");
 990 }
 991
 992 Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) {
 993   if (Constant *C = getImpl(Ty, V))
 994     return C;
 995   return Ty->getContext().pImpl->ArrayConstants.getOrCreate(Ty, V);
 996 }
 997
 998 Constant *ConstantArray::getImpl(ArrayType *Ty, ArrayRef<Constant*> V) {
 999   // Empty arrays are canonicalized to ConstantAggregateZero.
1000   if (V.empty())
1001     return ConstantAggregateZero::get(Ty);
1002
1003   for (unsigned i = 0, e = V.size(); i != e; ++i) {
1004     assert(V[i]->getType() == Ty->getElementType() &&
1005            "Wrong type in array element initializer");
1006   }
1007
1008   // If this is an all-zero array, return a ConstantAggregateZero object.  If
1009   // all undef, return an UndefValue, if "all simple", then return a
1010   // ConstantDataArray.
1011   Constant *C = V[0];
1012   if (isa<UndefValue>(C) && rangeOnlyContains(V.begin(), V.end(), C))
1013     return UndefValue::get(Ty);
1014
1015   if (C->isNullValue() && rangeOnlyContains(V.begin(), V.end(), C))
1016     return ConstantAggregateZero::get(Ty);
1017
1018   // Check to see if all of the elements are ConstantFP or ConstantInt and if
1019   // the element type is compatible with ConstantDataVector.  If so, use it.
1020   if (ConstantDataSequential::isElementTypeCompatible(C->getType()))
1021     return getSequenceIfElementsMatch<ConstantDataArray>(C, V);
1022
1023   // Otherwise, we really do want to create a ConstantArray.
1024   return nullptr;
1025 }
1026
1027 StructType *ConstantStruct::getTypeForElements(LLVMContext &Context,
1028                                                ArrayRef<Constant*> V,
1029                                                bool Packed) {
1030   unsigned VecSize = V.size();
1031   SmallVector<Type*, 16> EltTypes(VecSize);
1032   for (unsigned i = 0; i != VecSize; ++i)
1033     EltTypes[i] = V[i]->getType();
1034
1035   return StructType::get(Context, EltTypes, Packed);
1036 }
1037
1038
1039 StructType *ConstantStruct::getTypeForElements(ArrayRef<Constant*> V,
1040                                                bool Packed) {
1041   assert(!V.empty() &&
1042          "ConstantStruct::getTypeForElements cannot be called on empty list");
1043   return getTypeForElements(V[0]->getContext(), V, Packed);
1044 }
1045
1046 ConstantStruct::ConstantStruct(StructType *T, ArrayRef<Constant *> V)
1047     : ConstantAggregate(T, ConstantStructVal, V) {
1048   assert((T->isOpaque() || V.size() == T->getNumElements()) &&
1049          "Invalid initializer for constant struct");
1050 }
1051
1052 // ConstantStruct accessors.
1053 Constant *ConstantStruct::get(StructType *ST, ArrayRef<Constant*> V) {
1054   assert((ST->isOpaque() || ST->getNumElements() == V.size()) &&
1055          "Incorrect # elements specified to ConstantStruct::get");
1056
1057   // Create a ConstantAggregateZero value if all elements are zeros.
1058   bool isZero = true;
1059   bool isUndef = false;
1060
1061   if (!V.empty()) {
1062     isUndef = isa<UndefValue>(V[0]);
1063     isZero = V[0]->isNullValue();
1064     if (isUndef || isZero) {
1065       for (unsigned i = 0, e = V.size(); i != e; ++i) {
1066         if (!V[i]->isNullValue())
1067           isZero = false;
1068         if (!isa<UndefValue>(V[i]))
1069           isUndef = false;
1070       }
1071     }
1072   }
1073   if (isZero)
1074     return ConstantAggregateZero::get(ST);
1075   if (isUndef)
1076     return UndefValue::get(ST);
1077
1078   return ST->getContext().pImpl->StructConstants.getOrCreate(ST, V);
1079 }
1080
1081 ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V)
1082     : ConstantAggregate(T, ConstantVectorVal, V) {
1083   assert(V.size() == T->getNumElements() &&
1084          "Invalid initializer for constant vector");
1085 }
1086
1087 // ConstantVector accessors.
1088 Constant *ConstantVector::get(ArrayRef<Constant*> V) {
1089   if (Constant *C = getImpl(V))
1090     return C;
1091   VectorType *Ty = VectorType::get(V.front()->getType(), V.size());
1092   return Ty->getContext().pImpl->VectorConstants.getOrCreate(Ty, V);
1093 }
1094
1095 Constant *ConstantVector::getImpl(ArrayRef<Constant*> V) {
1096   assert(!V.empty() && "Vectors can't be empty");
1097   VectorType *T = VectorType::get(V.front()->getType(), V.size());
1098
1099   // If this is an all-undef or all-zero vector, return a
1100   // ConstantAggregateZero or UndefValue.
1101   Constant *C = V[0];
1102   bool isZero = C->isNullValue();
1103   bool isUndef = isa<UndefValue>(C);
1104
1105   if (isZero || isUndef) {
1106     for (unsigned i = 1, e = V.size(); i != e; ++i)
1107       if (V[i] != C) {
1108         isZero = isUndef = false;
1109         break;
1110       }
1111   }
1112
1113   if (isZero)
1114     return ConstantAggregateZero::get(T);
1115   if (isUndef)
1116     return UndefValue::get(T);
1117
1118   // Check to see if all of the elements are ConstantFP or ConstantInt and if
1119   // the element type is compatible with ConstantDataVector.  If so, use it.
1120   if (ConstantDataSequential::isElementTypeCompatible(C->getType()))
1121     return getSequenceIfElementsMatch<ConstantDataVector>(C, V);
1122
1123   // Otherwise, the element type isn't compatible with ConstantDataVector, or
1124   // the operand list contains a ConstantExpr or something else strange.
1125   return nullptr;
1126 }
1127
1128 Constant *ConstantVector::getSplat(unsigned NumElts, Constant *V) {
1129   // If this splat is compatible with ConstantDataVector, use it instead of
1130   // ConstantVector.
1131   if ((isa<ConstantFP>(V) || isa<ConstantInt>(V)) &&
1132       ConstantDataSequential::isElementTypeCompatible(V->getType()))
1133     return ConstantDataVector::getSplat(NumElts, V);
1134
1135   SmallVector<Constant*, 32> Elts(NumElts, V);
1136   return get(Elts);
1137 }
1138
1139 ConstantTokenNone *ConstantTokenNone::get(LLVMContext &Context) {
1140   LLVMContextImpl *pImpl = Context.pImpl;
1141   if (!pImpl->TheNoneToken)
1142     pImpl->TheNoneToken.reset(new ConstantTokenNone(Context));
1143   return pImpl->TheNoneToken.get();
1144 }
1145
1146 /// Remove the constant from the constant table.
1147 void ConstantTokenNone::destroyConstantImpl() {
1148   llvm_unreachable("You can't ConstantTokenNone->destroyConstantImpl()!");
1149 }
1150
1151 // Utility function for determining if a ConstantExpr is a CastOp or not. This
1152 // can't be inline because we don't want to #include Instruction.h into
1153 // Constant.h
1154 bool ConstantExpr::isCast() const {
1155   return Instruction::isCast(getOpcode());
1156 }
1157
1158 bool ConstantExpr::isCompare() const {
1159   return getOpcode() == Instruction::ICmp || getOpcode() == Instruction::FCmp;
1160 }
1161
1162 bool ConstantExpr::isGEPWithNoNotionalOverIndexing() const {
1163   if (getOpcode() != Instruction::GetElementPtr) return false;
1164
1165   gep_type_iterator GEPI = gep_type_begin(this), E = gep_type_end(this);
1166   User::const_op_iterator OI = std::next(this->op_begin());
1167
1168   // The remaining indices may be compile-time known integers within the bounds
1169   // of the corresponding notional static array types.
1170   for (; GEPI != E; ++GEPI, ++OI) {
1171     if (isa<UndefValue>(*OI))
1172       continue;
1173     auto *CI = dyn_cast<ConstantInt>(*OI);
1174     if (!CI || (GEPI.isBoundedSequential() &&
1175                 (CI->getValue().getActiveBits() > 64 ||
1176                  CI->getZExtValue() >= GEPI.getSequentialNumElements())))
1177       return false;
1178   }
1179
1180   // All the indices checked out.
1181   return true;
1182 }
1183
1184 bool ConstantExpr::hasIndices() const {
1185   return getOpcode() == Instruction::ExtractValue ||
1186          getOpcode() == Instruction::InsertValue;
1187 }
1188
1189 ArrayRef<unsigned> ConstantExpr::getIndices() const {
1190   if (const ExtractValueConstantExpr *EVCE =
1191         dyn_cast<ExtractValueConstantExpr>(this))
1192     return EVCE->Indices;
1193
1194   return cast<InsertValueConstantExpr>(this)->Indices;
1195 }
1196
1197 unsigned ConstantExpr::getPredicate() const {
1198   return cast<CompareConstantExpr>(this)->predicate;
1199 }
1200
1201 Constant *
1202 ConstantExpr::getWithOperandReplaced(unsigned OpNo, Constant *Op) const {
1203   assert(Op->getType() == getOperand(OpNo)->getType() &&
1204          "Replacing operand with value of different type!");
1205   if (getOperand(OpNo) == Op)
1206     return const_cast<ConstantExpr*>(this);
1207
1208   SmallVector<Constant*, 8> NewOps;
1209   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
1210     NewOps.push_back(i == OpNo ? Op : getOperand(i));
1211
1212   return getWithOperands(NewOps);
1213 }
1214
1215 Constant *ConstantExpr::getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1216                                         bool OnlyIfReduced, Type *SrcTy) const {
1217   assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
1218
1219   // If no operands changed return self.
1220   if (Ty == getType() && std::equal(Ops.begin(), Ops.end(), op_begin()))
1221     return const_cast<ConstantExpr*>(this);
1222
1223   Type *OnlyIfReducedTy = OnlyIfReduced ? Ty : nullptr;
1224   switch (getOpcode()) {
1225   case Instruction::Trunc:
1226   case Instruction::ZExt:
1227   case Instruction::SExt:
1228   case Instruction::FPTrunc:
1229   case Instruction::FPExt:
1230   case Instruction::UIToFP:
1231   case Instruction::SIToFP:
1232   case Instruction::FPToUI:
1233   case Instruction::FPToSI:
1234   case Instruction::PtrToInt:
1235   case Instruction::IntToPtr:
1236   case Instruction::BitCast:
1237   case Instruction::AddrSpaceCast:
1238     return ConstantExpr::getCast(getOpcode(), Ops[0], Ty, OnlyIfReduced);
1239   case Instruction::Select:
1240     return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2], OnlyIfReducedTy);
1241   case Instruction::InsertElement:
1242     return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2],
1243                                           OnlyIfReducedTy);
1244   case Instruction::ExtractElement:
1245     return ConstantExpr::getExtractElement(Ops[0], Ops[1], OnlyIfReducedTy);
1246   case Instruction::InsertValue:
1247     return ConstantExpr::getInsertValue(Ops[0], Ops[1], getIndices(),
1248                                         OnlyIfReducedTy);
1249   case Instruction::ExtractValue:
1250     return ConstantExpr::getExtractValue(Ops[0], getIndices(), OnlyIfReducedTy);
1251   case Instruction::ShuffleVector:
1252     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2],
1253                                           OnlyIfReducedTy);
1254   case Instruction::GetElementPtr: {
1255     auto *GEPO = cast<GEPOperator>(this);
1256     assert(SrcTy || (Ops[0]->getType() == getOperand(0)->getType()));
1257     return ConstantExpr::getGetElementPtr(
1258         SrcTy ? SrcTy : GEPO->getSourceElementType(), Ops[0], Ops.slice(1),
1259         GEPO->isInBounds(), GEPO->getInRangeIndex(), OnlyIfReducedTy);
1260   }
1261   case Instruction::ICmp:
1262   case Instruction::FCmp:
1263     return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1],
1264                                     OnlyIfReducedTy);
1265   default:
1266     assert(getNumOperands() == 2 && "Must be binary operator?");
1267     return ConstantExpr::get(getOpcode(), Ops[0], Ops[1], SubclassOptionalData,
1268                              OnlyIfReducedTy);
1269   }
1270 }
1271
1272
1273 //===----------------------------------------------------------------------===//
1274 //                      isValueValidForType implementations
1275
1276 bool ConstantInt::isValueValidForType(Type *Ty, uint64_t Val) {
1277   unsigned NumBits = Ty->getIntegerBitWidth(); // assert okay
1278   if (Ty->isIntegerTy(1))
1279     return Val == 0 || Val == 1;
1280   return isUIntN(NumBits, Val);
1281 }
1282
1283 bool ConstantInt::isValueValidForType(Type *Ty, int64_t Val) {
1284   unsigned NumBits = Ty->getIntegerBitWidth();
1285   if (Ty->isIntegerTy(1))
1286     return Val == 0 || Val == 1 || Val == -1;
1287   return isIntN(NumBits, Val);
1288 }
1289
1290 bool ConstantFP::isValueValidForType(Type *Ty, const APFloat& Val) {
1291   // convert modifies in place, so make a copy.
1292   APFloat Val2 = APFloat(Val);
1293   bool losesInfo;
1294   switch (Ty->getTypeID()) {
1295   default:
1296     return false;         // These can't be represented as floating point!
1297
1298   // FIXME rounding mode needs to be more flexible
1299   case Type::HalfTyID: {
1300     if (&Val2.getSemantics() == &APFloat::IEEEhalf())
1301       return true;
1302     Val2.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &losesInfo);
1303     return !losesInfo;
1304   }
1305   case Type::FloatTyID: {
1306     if (&Val2.getSemantics() == &APFloat::IEEEsingle())
1307       return true;
1308     Val2.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven, &losesInfo);
1309     return !losesInfo;
1310   }
1311   case Type::DoubleTyID: {
1312     if (&Val2.getSemantics() == &APFloat::IEEEhalf() ||
1313         &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1314         &Val2.getSemantics() == &APFloat::IEEEdouble())
1315       return true;
1316     Val2.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &losesInfo);
1317     return !losesInfo;
1318   }
1319   case Type::X86_FP80TyID:
1320     return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
1321            &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1322            &Val2.getSemantics() == &APFloat::IEEEdouble() ||
1323            &Val2.getSemantics() == &APFloat::x87DoubleExtended();
1324   case Type::FP128TyID:
1325     return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
1326            &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1327            &Val2.getSemantics() == &APFloat::IEEEdouble() ||
1328            &Val2.getSemantics() == &APFloat::IEEEquad();
1329   case Type::PPC_FP128TyID:
1330     return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
1331            &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1332            &Val2.getSemantics() == &APFloat::IEEEdouble() ||
1333            &Val2.getSemantics() == &APFloat::PPCDoubleDouble();
1334   }
1335 }
1336
1337
1338 //===----------------------------------------------------------------------===//
1339 //                      Factory Function Implementation
1340
1341 ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
1342   assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
1343          "Cannot create an aggregate zero of non-aggregate type!");
1344
1345   std::unique_ptr<ConstantAggregateZero> &Entry =
1346       Ty->getContext().pImpl->CAZConstants[Ty];
1347   if (!Entry)
1348     Entry.reset(new ConstantAggregateZero(Ty));
1349
1350   return Entry.get();
1351 }
1352
1353 /// Remove the constant from the constant table.
1354 void ConstantAggregateZero::destroyConstantImpl() {
1355   getContext().pImpl->CAZConstants.erase(getType());
1356 }
1357
1358 /// Remove the constant from the constant table.
1359 void ConstantArray::destroyConstantImpl() {
1360   getType()->getContext().pImpl->ArrayConstants.remove(this);
1361 }
1362
1363
1364 //---- ConstantStruct::get() implementation...
1365 //
1366
1367 /// Remove the constant from the constant table.
1368 void ConstantStruct::destroyConstantImpl() {
1369   getType()->getContext().pImpl->StructConstants.remove(this);
1370 }
1371
1372 /// Remove the constant from the constant table.
1373 void ConstantVector::destroyConstantImpl() {
1374   getType()->getContext().pImpl->VectorConstants.remove(this);
1375 }
1376
1377 Constant *Constant::getSplatValue() const {
1378   assert(this->getType()->isVectorTy() && "Only valid for vectors!");
1379   if (isa<ConstantAggregateZero>(this))
1380     return getNullValue(this->getType()->getVectorElementType());
1381   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
1382     return CV->getSplatValue();
1383   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
1384     return CV->getSplatValue();
1385   return nullptr;
1386 }
1387
1388 Constant *ConstantVector::getSplatValue() const {
1389   // Check out first element.
1390   Constant *Elt = getOperand(0);
1391   // Then make sure all remaining elements point to the same value.
1392   for (unsigned I = 1, E = getNumOperands(); I < E; ++I)
1393     if (getOperand(I) != Elt)
1394       return nullptr;
1395   return Elt;
1396 }
1397
1398 const APInt &Constant::getUniqueInteger() const {
1399   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
1400     return CI->getValue();
1401   assert(this->getSplatValue() && "Doesn't contain a unique integer!");
1402   const Constant *C = this->getAggregateElement(0U);
1403   assert(C && isa<ConstantInt>(C) && "Not a vector of numbers!");
1404   return cast<ConstantInt>(C)->getValue();
1405 }
1406
1407 //---- ConstantPointerNull::get() implementation.
1408 //
1409
1410 ConstantPointerNull *ConstantPointerNull::get(PointerType *Ty) {
1411   std::unique_ptr<ConstantPointerNull> &Entry =
1412       Ty->getContext().pImpl->CPNConstants[Ty];
1413   if (!Entry)
1414     Entry.reset(new ConstantPointerNull(Ty));
1415
1416   return Entry.get();
1417 }
1418
1419 /// Remove the constant from the constant table.
1420 void ConstantPointerNull::destroyConstantImpl() {
1421   getContext().pImpl->CPNConstants.erase(getType());
1422 }
1423
1424 UndefValue *UndefValue::get(Type *Ty) {
1425   std::unique_ptr<UndefValue> &Entry = Ty->getContext().pImpl->UVConstants[Ty];
1426   if (!Entry)
1427     Entry.reset(new UndefValue(Ty));
1428
1429   return Entry.get();
1430 }
1431
1432 /// Remove the constant from the constant table.
1433 void UndefValue::destroyConstantImpl() {
1434   // Free the constant and any dangling references to it.
1435   getContext().pImpl->UVConstants.erase(getType());
1436 }
1437
1438 BlockAddress *BlockAddress::get(BasicBlock *BB) {
1439   assert(BB->getParent() && "Block must have a parent");
1440   return get(BB->getParent(), BB);
1441 }
1442
1443 BlockAddress *BlockAddress::get(Function *F, BasicBlock *BB) {
1444   BlockAddress *&BA =
1445     F->getContext().pImpl->BlockAddresses[std::make_pair(F, BB)];
1446   if (!BA)
1447     BA = new BlockAddress(F, BB);
1448
1449   assert(BA->getFunction() == F && "Basic block moved between functions");
1450   return BA;
1451 }
1452
1453 BlockAddress::BlockAddress(Function *F, BasicBlock *BB)
1454 : Constant(Type::getInt8PtrTy(F->getContext()), Value::BlockAddressVal,
1455            &Op<0>(), 2) {
1456   setOperand(0, F);
1457   setOperand(1, BB);
1458   BB->AdjustBlockAddressRefCount(1);
1459 }
1460
1461 BlockAddress *BlockAddress::lookup(const BasicBlock *BB) {
1462   if (!BB->hasAddressTaken())
1463     return nullptr;
1464
1465   const Function *F = BB->getParent();
1466   assert(F && "Block must have a parent");
1467   BlockAddress *BA =
1468       F->getContext().pImpl->BlockAddresses.lookup(std::make_pair(F, BB));
1469   assert(BA && "Refcount and block address map disagree!");
1470   return BA;
1471 }
1472
1473 /// Remove the constant from the constant table.
1474 void BlockAddress::destroyConstantImpl() {
1475   getFunction()->getType()->getContext().pImpl
1476     ->BlockAddresses.erase(std::make_pair(getFunction(), getBasicBlock()));
1477   getBasicBlock()->AdjustBlockAddressRefCount(-1);
1478 }
1479
1480 Value *BlockAddress::handleOperandChangeImpl(Value *From, Value *To) {
1481   // This could be replacing either the Basic Block or the Function.  In either
1482   // case, we have to remove the map entry.
1483   Function *NewF = getFunction();
1484   BasicBlock *NewBB = getBasicBlock();
1485
1486   if (From == NewF)
1487     NewF = cast<Function>(To->stripPointerCasts());
1488   else {
1489     assert(From == NewBB && "From does not match any operand");
1490     NewBB = cast<BasicBlock>(To);
1491   }
1492
1493   // See if the 'new' entry already exists, if not, just update this in place
1494   // and return early.
1495   BlockAddress *&NewBA =
1496     getContext().pImpl->BlockAddresses[std::make_pair(NewF, NewBB)];
1497   if (NewBA)
1498     return NewBA;
1499
1500   getBasicBlock()->AdjustBlockAddressRefCount(-1);
1501
1502   // Remove the old entry, this can't cause the map to rehash (just a
1503   // tombstone will get added).
1504   getContext().pImpl->BlockAddresses.erase(std::make_pair(getFunction(),
1505                                                           getBasicBlock()));
1506   NewBA = this;
1507   setOperand(0, NewF);
1508   setOperand(1, NewBB);
1509   getBasicBlock()->AdjustBlockAddressRefCount(1);
1510
1511   // If we just want to keep the existing value, then return null.
1512   // Callers know that this means we shouldn't delete this value.
1513   return nullptr;
1514 }
1515
1516 //---- ConstantExpr::get() implementations.
1517 //
1518
1519 /// This is a utility function to handle folding of casts and lookup of the
1520 /// cast in the ExprConstants map. It is used by the various get* methods below.
1521 static Constant *getFoldedCast(Instruction::CastOps opc, Constant *C, Type *Ty,
1522                                bool OnlyIfReduced = false) {
1523   assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
1524   // Fold a few common cases
1525   if (Constant *FC = ConstantFoldCastInstruction(opc, C, Ty))
1526     return FC;
1527
1528   if (OnlyIfReduced)
1529     return nullptr;
1530
1531   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
1532
1533   // Look up the constant in the table first to ensure uniqueness.
1534   ConstantExprKeyType Key(opc, C);
1535
1536   return pImpl->ExprConstants.getOrCreate(Ty, Key);
1537 }
1538
1539 Constant *ConstantExpr::getCast(unsigned oc, Constant *C, Type *Ty,
1540                                 bool OnlyIfReduced) {
1541   Instruction::CastOps opc = Instruction::CastOps(oc);
1542   assert(Instruction::isCast(opc) && "opcode out of range");
1543   assert(C && Ty && "Null arguments to getCast");
1544   assert(CastInst::castIsValid(opc, C, Ty) && "Invalid constantexpr cast!");
1545
1546   switch (opc) {
1547   default:
1548     llvm_unreachable("Invalid cast opcode");
1549   case Instruction::Trunc:
1550     return getTrunc(C, Ty, OnlyIfReduced);
1551   case Instruction::ZExt:
1552     return getZExt(C, Ty, OnlyIfReduced);
1553   case Instruction::SExt:
1554     return getSExt(C, Ty, OnlyIfReduced);
1555   case Instruction::FPTrunc:
1556     return getFPTrunc(C, Ty, OnlyIfReduced);
1557   case Instruction::FPExt:
1558     return getFPExtend(C, Ty, OnlyIfReduced);
1559   case Instruction::UIToFP:
1560     return getUIToFP(C, Ty, OnlyIfReduced);
1561   case Instruction::SIToFP:
1562     return getSIToFP(C, Ty, OnlyIfReduced);
1563   case Instruction::FPToUI:
1564     return getFPToUI(C, Ty, OnlyIfReduced);
1565   case Instruction::FPToSI:
1566     return getFPToSI(C, Ty, OnlyIfReduced);
1567   case Instruction::PtrToInt:
1568     return getPtrToInt(C, Ty, OnlyIfReduced);
1569   case Instruction::IntToPtr:
1570     return getIntToPtr(C, Ty, OnlyIfReduced);
1571   case Instruction::BitCast:
1572     return getBitCast(C, Ty, OnlyIfReduced);
1573   case Instruction::AddrSpaceCast:
1574     return getAddrSpaceCast(C, Ty, OnlyIfReduced);
1575   }
1576 }
1577
1578 Constant *ConstantExpr::getZExtOrBitCast(Constant *C, Type *Ty) {
1579   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1580     return getBitCast(C, Ty);
1581   return getZExt(C, Ty);
1582 }
1583
1584 Constant *ConstantExpr::getSExtOrBitCast(Constant *C, Type *Ty) {
1585   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1586     return getBitCast(C, Ty);
1587   return getSExt(C, Ty);
1588 }
1589
1590 Constant *ConstantExpr::getTruncOrBitCast(Constant *C, Type *Ty) {
1591   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1592     return getBitCast(C, Ty);
1593   return getTrunc(C, Ty);
1594 }
1595
1596 Constant *ConstantExpr::getPointerCast(Constant *S, Type *Ty) {
1597   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
1598   assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
1599           "Invalid cast");
1600
1601   if (Ty->isIntOrIntVectorTy())
1602     return getPtrToInt(S, Ty);
1603
1604   unsigned SrcAS = S->getType()->getPointerAddressSpace();
1605   if (Ty->isPtrOrPtrVectorTy() && SrcAS != Ty->getPointerAddressSpace())
1606     return getAddrSpaceCast(S, Ty);
1607
1608   return getBitCast(S, Ty);
1609 }
1610
1611 Constant *ConstantExpr::getPointerBitCastOrAddrSpaceCast(Constant *S,
1612                                                          Type *Ty) {
1613   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
1614   assert(Ty->isPtrOrPtrVectorTy() && "Invalid cast");
1615
1616   if (S->getType()->getPointerAddressSpace() != Ty->getPointerAddressSpace())
1617     return getAddrSpaceCast(S, Ty);
1618
1619   return getBitCast(S, Ty);
1620 }
1621
1622 Constant *ConstantExpr::getIntegerCast(Constant *C, Type *Ty, bool isSigned) {
1623   assert(C->getType()->isIntOrIntVectorTy() &&
1624          Ty->isIntOrIntVectorTy() && "Invalid cast");
1625   unsigned SrcBits = C->getType()->getScalarSizeInBits();
1626   unsigned DstBits = Ty->getScalarSizeInBits();
1627   Instruction::CastOps opcode =
1628     (SrcBits == DstBits ? Instruction::BitCast :
1629      (SrcBits > DstBits ? Instruction::Trunc :
1630       (isSigned ? Instruction::SExt : Instruction::ZExt)));
1631   return getCast(opcode, C, Ty);
1632 }
1633
1634 Constant *ConstantExpr::getFPCast(Constant *C, Type *Ty) {
1635   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
1636          "Invalid cast");
1637   unsigned SrcBits = C->getType()->getScalarSizeInBits();
1638   unsigned DstBits = Ty->getScalarSizeInBits();
1639   if (SrcBits == DstBits)
1640     return C; // Avoid a useless cast
1641   Instruction::CastOps opcode =
1642     (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt);
1643   return getCast(opcode, C, Ty);
1644 }
1645
1646 Constant *ConstantExpr::getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced) {
1647 #ifndef NDEBUG
1648   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1649   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1650 #endif
1651   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1652   assert(C->getType()->isIntOrIntVectorTy() && "Trunc operand must be integer");
1653   assert(Ty->isIntOrIntVectorTy() && "Trunc produces only integral");
1654   assert(C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
1655          "SrcTy must be larger than DestTy for Trunc!");
1656
1657   return getFoldedCast(Instruction::Trunc, C, Ty, OnlyIfReduced);
1658 }
1659
1660 Constant *ConstantExpr::getSExt(Constant *C, Type *Ty, bool OnlyIfReduced) {
1661 #ifndef NDEBUG
1662   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1663   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1664 #endif
1665   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1666   assert(C->getType()->isIntOrIntVectorTy() && "SExt operand must be integral");
1667   assert(Ty->isIntOrIntVectorTy() && "SExt produces only integer");
1668   assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1669          "SrcTy must be smaller than DestTy for SExt!");
1670
1671   return getFoldedCast(Instruction::SExt, C, Ty, OnlyIfReduced);
1672 }
1673
1674 Constant *ConstantExpr::getZExt(Constant *C, Type *Ty, bool OnlyIfReduced) {
1675 #ifndef NDEBUG
1676   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1677   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1678 #endif
1679   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1680   assert(C->getType()->isIntOrIntVectorTy() && "ZEXt operand must be integral");
1681   assert(Ty->isIntOrIntVectorTy() && "ZExt produces only integer");
1682   assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1683          "SrcTy must be smaller than DestTy for ZExt!");
1684
1685   return getFoldedCast(Instruction::ZExt, C, Ty, OnlyIfReduced);
1686 }
1687
1688 Constant *ConstantExpr::getFPTrunc(Constant *C, Type *Ty, bool OnlyIfReduced) {
1689 #ifndef NDEBUG
1690   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1691   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1692 #endif
1693   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1694   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
1695          C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
1696          "This is an illegal floating point truncation!");
1697   return getFoldedCast(Instruction::FPTrunc, C, Ty, OnlyIfReduced);
1698 }
1699
1700 Constant *ConstantExpr::getFPExtend(Constant *C, Type *Ty, bool OnlyIfReduced) {
1701 #ifndef NDEBUG
1702   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1703   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1704 #endif
1705   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1706   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
1707          C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1708          "This is an illegal floating point extension!");
1709   return getFoldedCast(Instruction::FPExt, C, Ty, OnlyIfReduced);
1710 }
1711
1712 Constant *ConstantExpr::getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced) {
1713 #ifndef NDEBUG
1714   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1715   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1716 #endif
1717   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1718   assert(C->getType()->isIntOrIntVectorTy() && Ty->isFPOrFPVectorTy() &&
1719          "This is an illegal uint to floating point cast!");
1720   return getFoldedCast(Instruction::UIToFP, C, Ty, OnlyIfReduced);
1721 }
1722
1723 Constant *ConstantExpr::getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced) {
1724 #ifndef NDEBUG
1725   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1726   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1727 #endif
1728   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1729   assert(C->getType()->isIntOrIntVectorTy() && Ty->isFPOrFPVectorTy() &&
1730          "This is an illegal sint to floating point cast!");
1731   return getFoldedCast(Instruction::SIToFP, C, Ty, OnlyIfReduced);
1732 }
1733
1734 Constant *ConstantExpr::getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced) {
1735 #ifndef NDEBUG
1736   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1737   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1738 #endif
1739   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1740   assert(C->getType()->isFPOrFPVectorTy() && Ty->isIntOrIntVectorTy() &&
1741          "This is an illegal floating point to uint cast!");
1742   return getFoldedCast(Instruction::FPToUI, C, Ty, OnlyIfReduced);
1743 }
1744
1745 Constant *ConstantExpr::getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced) {
1746 #ifndef NDEBUG
1747   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1748   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1749 #endif
1750   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1751   assert(C->getType()->isFPOrFPVectorTy() && Ty->isIntOrIntVectorTy() &&
1752          "This is an illegal floating point to sint cast!");
1753   return getFoldedCast(Instruction::FPToSI, C, Ty, OnlyIfReduced);
1754 }
1755
1756 Constant *ConstantExpr::getPtrToInt(Constant *C, Type *DstTy,
1757                                     bool OnlyIfReduced) {
1758   assert(C->getType()->isPtrOrPtrVectorTy() &&
1759          "PtrToInt source must be pointer or pointer vector");
1760   assert(DstTy->isIntOrIntVectorTy() &&
1761          "PtrToInt destination must be integer or integer vector");
1762   assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
1763   if (isa<VectorType>(C->getType()))
1764     assert(C->getType()->getVectorNumElements()==DstTy->getVectorNumElements()&&
1765            "Invalid cast between a different number of vector elements");
1766   return getFoldedCast(Instruction::PtrToInt, C, DstTy, OnlyIfReduced);
1767 }
1768
1769 Constant *ConstantExpr::getIntToPtr(Constant *C, Type *DstTy,
1770                                     bool OnlyIfReduced) {
1771   assert(C->getType()->isIntOrIntVectorTy() &&
1772          "IntToPtr source must be integer or integer vector");
1773   assert(DstTy->isPtrOrPtrVectorTy() &&
1774          "IntToPtr destination must be a pointer or pointer vector");
1775   assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
1776   if (isa<VectorType>(C->getType()))
1777     assert(C->getType()->getVectorNumElements()==DstTy->getVectorNumElements()&&
1778            "Invalid cast between a different number of vector elements");
1779   return getFoldedCast(Instruction::IntToPtr, C, DstTy, OnlyIfReduced);
1780 }
1781
1782 Constant *ConstantExpr::getBitCast(Constant *C, Type *DstTy,
1783                                    bool OnlyIfReduced) {
1784   assert(CastInst::castIsValid(Instruction::BitCast, C, DstTy) &&
1785          "Invalid constantexpr bitcast!");
1786
1787   // It is common to ask for a bitcast of a value to its own type, handle this
1788   // speedily.
1789   if (C->getType() == DstTy) return C;
1790
1791   return getFoldedCast(Instruction::BitCast, C, DstTy, OnlyIfReduced);
1792 }
1793
1794 Constant *ConstantExpr::getAddrSpaceCast(Constant *C, Type *DstTy,
1795                                          bool OnlyIfReduced) {
1796   assert(CastInst::castIsValid(Instruction::AddrSpaceCast, C, DstTy) &&
1797          "Invalid constantexpr addrspacecast!");
1798
1799   // Canonicalize addrspacecasts between different pointer types by first
1800   // bitcasting the pointer type and then converting the address space.
1801   PointerType *SrcScalarTy = cast<PointerType>(C->getType()->getScalarType());
1802   PointerType *DstScalarTy = cast<PointerType>(DstTy->getScalarType());
1803   Type *DstElemTy = DstScalarTy->getElementType();
1804   if (SrcScalarTy->getElementType() != DstElemTy) {
1805     Type *MidTy = PointerType::get(DstElemTy, SrcScalarTy->getAddressSpace());
1806     if (VectorType *VT = dyn_cast<VectorType>(DstTy)) {
1807       // Handle vectors of pointers.
1808       MidTy = VectorType::get(MidTy, VT->getNumElements());
1809     }
1810     C = getBitCast(C, MidTy);
1811   }
1812   return getFoldedCast(Instruction::AddrSpaceCast, C, DstTy, OnlyIfReduced);
1813 }
1814
1815 Constant *ConstantExpr::get(unsigned Opcode, Constant *C, unsigned Flags,
1816                             Type *OnlyIfReducedTy) {
1817   // Check the operands for consistency first.
1818   assert(Instruction::isUnaryOp(Opcode) &&
1819          "Invalid opcode in unary constant expression");
1820
1821 #ifndef NDEBUG
1822   switch (Opcode) {
1823   case Instruction::FNeg:
1824     assert(C->getType()->isFPOrFPVectorTy() &&
1825            "Tried to create a floating-point operation on a "
1826            "non-floating-point type!");
1827     break;
1828   default:
1829     break;
1830   }
1831 #endif
1832
1833   if (Constant *FC = ConstantFoldUnaryInstruction(Opcode, C))
1834     return FC;
1835
1836   if (OnlyIfReducedTy == C->getType())
1837     return nullptr;
1838
1839   Constant *ArgVec[] = { C };
1840   ConstantExprKeyType Key(Opcode, ArgVec, 0, Flags);
1841
1842   LLVMContextImpl *pImpl = C->getContext().pImpl;
1843   return pImpl->ExprConstants.getOrCreate(C->getType(), Key);
1844 }
1845
1846 Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
1847                             unsigned Flags, Type *OnlyIfReducedTy) {
1848   // Check the operands for consistency first.
1849   assert(Instruction::isBinaryOp(Opcode) &&
1850          "Invalid opcode in binary constant expression");
1851   assert(C1->getType() == C2->getType() &&
1852          "Operand types in binary constant expression should match");
1853
1854 #ifndef NDEBUG
1855   switch (Opcode) {
1856   case Instruction::Add:
1857   case Instruction::Sub:
1858   case Instruction::Mul:
1859   case Instruction::UDiv:
1860   case Instruction::SDiv:
1861   case Instruction::URem:
1862   case Instruction::SRem:
1863     assert(C1->getType()->isIntOrIntVectorTy() &&
1864            "Tried to create an integer operation on a non-integer type!");
1865     break;
1866   case Instruction::FAdd:
1867   case Instruction::FSub:
1868   case Instruction::FMul:
1869   case Instruction::FDiv:
1870   case Instruction::FRem:
1871     assert(C1->getType()->isFPOrFPVectorTy() &&
1872            "Tried to create a floating-point operation on a "
1873            "non-floating-point type!");
1874     break;
1875   case Instruction::And:
1876   case Instruction::Or:
1877   case Instruction::Xor:
1878     assert(C1->getType()->isIntOrIntVectorTy() &&
1879            "Tried to create a logical operation on a non-integral type!");
1880     break;
1881   case Instruction::Shl:
1882   case Instruction::LShr:
1883   case Instruction::AShr:
1884     assert(C1->getType()->isIntOrIntVectorTy() &&
1885            "Tried to create a shift operation on a non-integer type!");
1886     break;
1887   default:
1888     break;
1889   }
1890 #endif
1891
1892   if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
1893     return FC;
1894
1895   if (OnlyIfReducedTy == C1->getType())
1896     return nullptr;
1897
1898   Constant *ArgVec[] = { C1, C2 };
1899   ConstantExprKeyType Key(Opcode, ArgVec, 0, Flags);
1900
1901   LLVMContextImpl *pImpl = C1->getContext().pImpl;
1902   return pImpl->ExprConstants.getOrCreate(C1->getType(), Key);
1903 }
1904
1905 Constant *ConstantExpr::getSizeOf(Type* Ty) {
1906   // sizeof is implemented as: (i64) gep (Ty*)null, 1
1907   // Note that a non-inbounds gep is used, as null isn't within any object.
1908   Constant *GEPIdx = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
1909   Constant *GEP = getGetElementPtr(
1910       Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
1911   return getPtrToInt(GEP,
1912                      Type::getInt64Ty(Ty->getContext()));
1913 }
1914
1915 Constant *ConstantExpr::getAlignOf(Type* Ty) {
1916   // alignof is implemented as: (i64) gep ({i1,Ty}*)null, 0, 1
1917   // Note that a non-inbounds gep is used, as null isn't within any object.
1918   Type *AligningTy = StructType::get(Type::getInt1Ty(Ty->getContext()), Ty);
1919   Constant *NullPtr = Constant::getNullValue(AligningTy->getPointerTo(0));
1920   Constant *Zero = ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0);
1921   Constant *One = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
1922   Constant *Indices[2] = { Zero, One };
1923   Constant *GEP = getGetElementPtr(AligningTy, NullPtr, Indices);
1924   return getPtrToInt(GEP,
1925                      Type::getInt64Ty(Ty->getContext()));
1926 }
1927
1928 Constant *ConstantExpr::getOffsetOf(StructType* STy, unsigned FieldNo) {
1929   return getOffsetOf(STy, ConstantInt::get(Type::getInt32Ty(STy->getContext()),
1930                                            FieldNo));
1931 }
1932
1933 Constant *ConstantExpr::getOffsetOf(Type* Ty, Constant *FieldNo) {
1934   // offsetof is implemented as: (i64) gep (Ty*)null, 0, FieldNo
1935   // Note that a non-inbounds gep is used, as null isn't within any object.
1936   Constant *GEPIdx[] = {
1937     ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0),
1938     FieldNo
1939   };
1940   Constant *GEP = getGetElementPtr(
1941       Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
1942   return getPtrToInt(GEP,
1943                      Type::getInt64Ty(Ty->getContext()));
1944 }
1945
1946 Constant *ConstantExpr::getCompare(unsigned short Predicate, Constant *C1,
1947                                    Constant *C2, bool OnlyIfReduced) {
1948   assert(C1->getType() == C2->getType() && "Op types should be identical!");
1949
1950   switch (Predicate) {
1951   default: llvm_unreachable("Invalid CmpInst predicate");
1952   case CmpInst::FCMP_FALSE: case CmpInst::FCMP_OEQ: case CmpInst::FCMP_OGT:
1953   case CmpInst::FCMP_OGE:   case CmpInst::FCMP_OLT: case CmpInst::FCMP_OLE:
1954   case CmpInst::FCMP_ONE:   case CmpInst::FCMP_ORD: case CmpInst::FCMP_UNO:
1955   case CmpInst::FCMP_UEQ:   case CmpInst::FCMP_UGT: case CmpInst::FCMP_UGE:
1956   case CmpInst::FCMP_ULT:   case CmpInst::FCMP_ULE: case CmpInst::FCMP_UNE:
1957   case CmpInst::FCMP_TRUE:
1958     return getFCmp(Predicate, C1, C2, OnlyIfReduced);
1959
1960   case CmpInst::ICMP_EQ:  case CmpInst::ICMP_NE:  case CmpInst::ICMP_UGT:
1961   case CmpInst::ICMP_UGE: case CmpInst::ICMP_ULT: case CmpInst::ICMP_ULE:
1962   case CmpInst::ICMP_SGT: case CmpInst::ICMP_SGE: case CmpInst::ICMP_SLT:
1963   case CmpInst::ICMP_SLE:
1964     return getICmp(Predicate, C1, C2, OnlyIfReduced);
1965   }
1966 }
1967
1968 Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2,
1969                                   Type *OnlyIfReducedTy) {
1970   assert(!SelectInst::areInvalidOperands(C, V1, V2)&&"Invalid select operands");
1971
1972   if (Constant *SC = ConstantFoldSelectInstruction(C, V1, V2))
1973     return SC;        // Fold common cases
1974
1975   if (OnlyIfReducedTy == V1->getType())
1976     return nullptr;
1977
1978   Constant *ArgVec[] = { C, V1, V2 };
1979   ConstantExprKeyType Key(Instruction::Select, ArgVec);
1980
1981   LLVMContextImpl *pImpl = C->getContext().pImpl;
1982   return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
1983 }
1984
1985 Constant *ConstantExpr::getGetElementPtr(Type *Ty, Constant *C,
1986                                          ArrayRef<Value *> Idxs, bool InBounds,
1987                                          Optional<unsigned> InRangeIndex,
1988                                          Type *OnlyIfReducedTy) {
1989   if (!Ty)
1990     Ty = cast<PointerType>(C->getType()->getScalarType())->getElementType();
1991   else
1992     assert(Ty ==
1993            cast<PointerType>(C->getType()->getScalarType())->getElementType());
1994
1995   if (Constant *FC =
1996           ConstantFoldGetElementPtr(Ty, C, InBounds, InRangeIndex, Idxs))
1997     return FC;          // Fold a few common cases.
1998
1999   // Get the result type of the getelementptr!
2000   Type *DestTy = GetElementPtrInst::getIndexedType(Ty, Idxs);
2001   assert(DestTy && "GEP indices invalid!");
2002   unsigned AS = C->getType()->getPointerAddressSpace();
2003   Type *ReqTy = DestTy->getPointerTo(AS);
2004
2005   unsigned NumVecElts = 0;
2006   if (C->getType()->isVectorTy())
2007     NumVecElts = C->getType()->getVectorNumElements();
2008   else for (auto Idx : Idxs)
2009     if (Idx->getType()->isVectorTy())
2010       NumVecElts = Idx->getType()->getVectorNumElements();
2011
2012   if (NumVecElts)
2013     ReqTy = VectorType::get(ReqTy, NumVecElts);
2014
2015   if (OnlyIfReducedTy == ReqTy)
2016     return nullptr;
2017
2018   // Look up the constant in the table first to ensure uniqueness
2019   std::vector<Constant*> ArgVec;
2020   ArgVec.reserve(1 + Idxs.size());
2021   ArgVec.push_back(C);
2022   for (unsigned i = 0, e = Idxs.size(); i != e; ++i) {
2023     assert((!Idxs[i]->getType()->isVectorTy() ||
2024             Idxs[i]->getType()->getVectorNumElements() == NumVecElts) &&
2025            "getelementptr index type missmatch");
2026
2027     Constant *Idx = cast<Constant>(Idxs[i]);
2028     if (NumVecElts && !Idxs[i]->getType()->isVectorTy())
2029       Idx = ConstantVector::getSplat(NumVecElts, Idx);
2030     ArgVec.push_back(Idx);
2031   }
2032
2033   unsigned SubClassOptionalData = InBounds ? GEPOperator::IsInBounds : 0;
2034   if (InRangeIndex && *InRangeIndex < 63)
2035     SubClassOptionalData |= (*InRangeIndex + 1) << 1;
2036   const ConstantExprKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
2037                                 SubClassOptionalData, None, Ty);
2038
2039   LLVMContextImpl *pImpl = C->getContext().pImpl;
2040   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2041 }
2042
2043 Constant *ConstantExpr::getICmp(unsigned short pred, Constant *LHS,
2044                                 Constant *RHS, bool OnlyIfReduced) {
2045   assert(LHS->getType() == RHS->getType());
2046   assert(CmpInst::isIntPredicate((CmpInst::Predicate)pred) &&
2047          "Invalid ICmp Predicate");
2048
2049   if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
2050     return FC;          // Fold a few common cases...
2051
2052   if (OnlyIfReduced)
2053     return nullptr;
2054
2055   // Look up the constant in the table first to ensure uniqueness
2056   Constant *ArgVec[] = { LHS, RHS };
2057   // Get the key type with both the opcode and predicate
2058   const ConstantExprKeyType Key(Instruction::ICmp, ArgVec, pred);
2059
2060   Type *ResultTy = Type::getInt1Ty(LHS->getContext());
2061   if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
2062     ResultTy = VectorType::get(ResultTy, VT->getNumElements());
2063
2064   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
2065   return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
2066 }
2067
2068 Constant *ConstantExpr::getFCmp(unsigned short pred, Constant *LHS,
2069                                 Constant *RHS, bool OnlyIfReduced) {
2070   assert(LHS->getType() == RHS->getType());
2071   assert(CmpInst::isFPPredicate((CmpInst::Predicate)pred) &&
2072          "Invalid FCmp Predicate");
2073
2074   if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
2075     return FC;          // Fold a few common cases...
2076
2077   if (OnlyIfReduced)
2078     return nullptr;
2079
2080   // Look up the constant in the table first to ensure uniqueness
2081   Constant *ArgVec[] = { LHS, RHS };
2082   // Get the key type with both the opcode and predicate
2083   const ConstantExprKeyType Key(Instruction::FCmp, ArgVec, pred);
2084
2085   Type *ResultTy = Type::getInt1Ty(LHS->getContext());
2086   if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
2087     ResultTy = VectorType::get(ResultTy, VT->getNumElements());
2088
2089   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
2090   return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
2091 }
2092
2093 Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx,
2094                                           Type *OnlyIfReducedTy) {
2095   assert(Val->getType()->isVectorTy() &&
2096          "Tried to create extractelement operation on non-vector type!");
2097   assert(Idx->getType()->isIntegerTy() &&
2098          "Extractelement index must be an integer type!");
2099
2100   if (Constant *FC = ConstantFoldExtractElementInstruction(Val, Idx))
2101     return FC;          // Fold a few common cases.
2102
2103   Type *ReqTy = Val->getType()->getVectorElementType();
2104   if (OnlyIfReducedTy == ReqTy)
2105     return nullptr;
2106
2107   // Look up the constant in the table first to ensure uniqueness
2108   Constant *ArgVec[] = { Val, Idx };
2109   const ConstantExprKeyType Key(Instruction::ExtractElement, ArgVec);
2110
2111   LLVMContextImpl *pImpl = Val->getContext().pImpl;
2112   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2113 }
2114
2115 Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
2116                                          Constant *Idx, Type *OnlyIfReducedTy) {
2117   assert(Val->getType()->isVectorTy() &&
2118          "Tried to create insertelement operation on non-vector type!");
2119   assert(Elt->getType() == Val->getType()->getVectorElementType() &&
2120          "Insertelement types must match!");
2121   assert(Idx->getType()->isIntegerTy() &&
2122          "Insertelement index must be i32 type!");
2123
2124   if (Constant *FC = ConstantFoldInsertElementInstruction(Val, Elt, Idx))
2125     return FC;          // Fold a few common cases.
2126
2127   if (OnlyIfReducedTy == Val->getType())
2128     return nullptr;
2129
2130   // Look up the constant in the table first to ensure uniqueness
2131   Constant *ArgVec[] = { Val, Elt, Idx };
2132   const ConstantExprKeyType Key(Instruction::InsertElement, ArgVec);
2133
2134   LLVMContextImpl *pImpl = Val->getContext().pImpl;
2135   return pImpl->ExprConstants.getOrCreate(Val->getType(), Key);
2136 }
2137
2138 Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
2139                                          Constant *Mask, Type *OnlyIfReducedTy) {
2140   assert(ShuffleVectorInst::isValidOperands(V1, V2, Mask) &&
2141          "Invalid shuffle vector constant expr operands!");
2142
2143   if (Constant *FC = ConstantFoldShuffleVectorInstruction(V1, V2, Mask))
2144     return FC;          // Fold a few common cases.
2145
2146   unsigned NElts = Mask->getType()->getVectorNumElements();
2147   Type *EltTy = V1->getType()->getVectorElementType();
2148   Type *ShufTy = VectorType::get(EltTy, NElts);
2149
2150   if (OnlyIfReducedTy == ShufTy)
2151     return nullptr;
2152
2153   // Look up the constant in the table first to ensure uniqueness
2154   Constant *ArgVec[] = { V1, V2, Mask };
2155   const ConstantExprKeyType Key(Instruction::ShuffleVector, ArgVec);
2156
2157   LLVMContextImpl *pImpl = ShufTy->getContext().pImpl;
2158   return pImpl->ExprConstants.getOrCreate(ShufTy, Key);
2159 }
2160
2161 Constant *ConstantExpr::getInsertValue(Constant *Agg, Constant *Val,
2162                                        ArrayRef<unsigned> Idxs,
2163                                        Type *OnlyIfReducedTy) {
2164   assert(Agg->getType()->isFirstClassType() &&
2165          "Non-first-class type for constant insertvalue expression");
2166
2167   assert(ExtractValueInst::getIndexedType(Agg->getType(),
2168                                           Idxs) == Val->getType() &&
2169          "insertvalue indices invalid!");
2170   Type *ReqTy = Val->getType();
2171
2172   if (Constant *FC = ConstantFoldInsertValueInstruction(Agg, Val, Idxs))
2173     return FC;
2174
2175   if (OnlyIfReducedTy == ReqTy)
2176     return nullptr;
2177
2178   Constant *ArgVec[] = { Agg, Val };
2179   const ConstantExprKeyType Key(Instruction::InsertValue, ArgVec, 0, 0, Idxs);
2180
2181   LLVMContextImpl *pImpl = Agg->getContext().pImpl;
2182   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2183 }
2184
2185 Constant *ConstantExpr::getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
2186                                         Type *OnlyIfReducedTy) {
2187   assert(Agg->getType()->isFirstClassType() &&
2188          "Tried to create extractelement operation on non-first-class type!");
2189
2190   Type *ReqTy = ExtractValueInst::getIndexedType(Agg->getType(), Idxs);
2191   (void)ReqTy;
2192   assert(ReqTy && "extractvalue indices invalid!");
2193
2194   assert(Agg->getType()->isFirstClassType() &&
2195          "Non-first-class type for constant extractvalue expression");
2196   if (Constant *FC = ConstantFoldExtractValueInstruction(Agg, Idxs))
2197     return FC;
2198
2199   if (OnlyIfReducedTy == ReqTy)
2200     return nullptr;
2201
2202   Constant *ArgVec[] = { Agg };
2203   const ConstantExprKeyType Key(Instruction::ExtractValue, ArgVec, 0, 0, Idxs);
2204
2205   LLVMContextImpl *pImpl = Agg->getContext().pImpl;
2206   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2207 }
2208
2209 Constant *ConstantExpr::getNeg(Constant *C, bool HasNUW, bool HasNSW) {
2210   assert(C->getType()->isIntOrIntVectorTy() &&
2211          "Cannot NEG a nonintegral value!");
2212   return getSub(ConstantFP::getZeroValueForNegation(C->getType()),
2213                 C, HasNUW, HasNSW);
2214 }
2215
2216 Constant *ConstantExpr::getFNeg(Constant *C) {
2217   assert(C->getType()->isFPOrFPVectorTy() &&
2218          "Cannot FNEG a non-floating-point value!");
2219   return get(Instruction::FNeg, C);
2220 }
2221
2222 Constant *ConstantExpr::getNot(Constant *C) {
2223   assert(C->getType()->isIntOrIntVectorTy() &&
2224          "Cannot NOT a nonintegral value!");
2225   return get(Instruction::Xor, C, Constant::getAllOnesValue(C->getType()));
2226 }
2227
2228 Constant *ConstantExpr::getAdd(Constant *C1, Constant *C2,
2229                                bool HasNUW, bool HasNSW) {
2230   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2231                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2232   return get(Instruction::Add, C1, C2, Flags);
2233 }
2234
2235 Constant *ConstantExpr::getFAdd(Constant *C1, Constant *C2) {
2236   return get(Instruction::FAdd, C1, C2);
2237 }
2238
2239 Constant *ConstantExpr::getSub(Constant *C1, Constant *C2,
2240                                bool HasNUW, bool HasNSW) {
2241   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2242                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2243   return get(Instruction::Sub, C1, C2, Flags);
2244 }
2245
2246 Constant *ConstantExpr::getFSub(Constant *C1, Constant *C2) {
2247   return get(Instruction::FSub, C1, C2);
2248 }
2249
2250 Constant *ConstantExpr::getMul(Constant *C1, Constant *C2,
2251                                bool HasNUW, bool HasNSW) {
2252   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2253                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2254   return get(Instruction::Mul, C1, C2, Flags);
2255 }
2256
2257 Constant *ConstantExpr::getFMul(Constant *C1, Constant *C2) {
2258   return get(Instruction::FMul, C1, C2);
2259 }
2260
2261 Constant *ConstantExpr::getUDiv(Constant *C1, Constant *C2, bool isExact) {
2262   return get(Instruction::UDiv, C1, C2,
2263              isExact ? PossiblyExactOperator::IsExact : 0);
2264 }
2265
2266 Constant *ConstantExpr::getSDiv(Constant *C1, Constant *C2, bool isExact) {
2267   return get(Instruction::SDiv, C1, C2,
2268              isExact ? PossiblyExactOperator::IsExact : 0);
2269 }
2270
2271 Constant *ConstantExpr::getFDiv(Constant *C1, Constant *C2) {
2272   return get(Instruction::FDiv, C1, C2);
2273 }
2274
2275 Constant *ConstantExpr::getURem(Constant *C1, Constant *C2) {
2276   return get(Instruction::URem, C1, C2);
2277 }
2278
2279 Constant *ConstantExpr::getSRem(Constant *C1, Constant *C2) {
2280   return get(Instruction::SRem, C1, C2);
2281 }
2282
2283 Constant *ConstantExpr::getFRem(Constant *C1, Constant *C2) {
2284   return get(Instruction::FRem, C1, C2);
2285 }
2286
2287 Constant *ConstantExpr::getAnd(Constant *C1, Constant *C2) {
2288   return get(Instruction::And, C1, C2);
2289 }
2290
2291 Constant *ConstantExpr::getOr(Constant *C1, Constant *C2) {
2292   return get(Instruction::Or, C1, C2);
2293 }
2294
2295 Constant *ConstantExpr::getXor(Constant *C1, Constant *C2) {
2296   return get(Instruction::Xor, C1, C2);
2297 }
2298
2299 Constant *ConstantExpr::getShl(Constant *C1, Constant *C2,
2300                                bool HasNUW, bool HasNSW) {
2301   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2302                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2303   return get(Instruction::Shl, C1, C2, Flags);
2304 }
2305
2306 Constant *ConstantExpr::getLShr(Constant *C1, Constant *C2, bool isExact) {
2307   return get(Instruction::LShr, C1, C2,
2308              isExact ? PossiblyExactOperator::IsExact : 0);
2309 }
2310
2311 Constant *ConstantExpr::getAShr(Constant *C1, Constant *C2, bool isExact) {
2312   return get(Instruction::AShr, C1, C2,
2313              isExact ? PossiblyExactOperator::IsExact : 0);
2314 }
2315
2316 Constant *ConstantExpr::getBinOpIdentity(unsigned Opcode, Type *Ty,
2317                                          bool AllowRHSConstant) {
2318   assert(Instruction::isBinaryOp(Opcode) && "Only binops allowed");
2319
2320   // Commutative opcodes: it does not matter if AllowRHSConstant is set.
2321   if (Instruction::isCommutative(Opcode)) {
2322     switch (Opcode) {
2323       case Instruction::Add: // X + 0 = X
2324       case Instruction::Or:  // X | 0 = X
2325       case Instruction::Xor: // X ^ 0 = X
2326         return Constant::getNullValue(Ty);
2327       case Instruction::Mul: // X * 1 = X
2328         return ConstantInt::get(Ty, 1);
2329       case Instruction::And: // X & -1 = X
2330         return Constant::getAllOnesValue(Ty);
2331       case Instruction::FAdd: // X + -0.0 = X
2332         // TODO: If the fadd has 'nsz', should we return +0.0?
2333         return ConstantFP::getNegativeZero(Ty);
2334       case Instruction::FMul: // X * 1.0 = X
2335         return ConstantFP::get(Ty, 1.0);
2336       default:
2337         llvm_unreachable("Every commutative binop has an identity constant");
2338     }
2339   }
2340
2341   // Non-commutative opcodes: AllowRHSConstant must be set.
2342   if (!AllowRHSConstant)
2343     return nullptr;
2344
2345   switch (Opcode) {
2346     case Instruction::Sub:  // X - 0 = X
2347     case Instruction::Shl:  // X << 0 = X
2348     case Instruction::LShr: // X >>u 0 = X
2349     case Instruction::AShr: // X >> 0 = X
2350     case Instruction::FSub: // X - 0.0 = X
2351       return Constant::getNullValue(Ty);
2352     case Instruction::SDiv: // X / 1 = X
2353     case Instruction::UDiv: // X /u 1 = X
2354       return ConstantInt::get(Ty, 1);
2355     case Instruction::FDiv: // X / 1.0 = X
2356       return ConstantFP::get(Ty, 1.0);
2357     default:
2358       return nullptr;
2359   }
2360 }
2361
2362 Constant *ConstantExpr::getBinOpAbsorber(unsigned Opcode, Type *Ty) {
2363   switch (Opcode) {
2364   default:
2365     // Doesn't have an absorber.
2366     return nullptr;
2367
2368   case Instruction::Or:
2369     return Constant::getAllOnesValue(Ty);
2370
2371   case Instruction::And:
2372   case Instruction::Mul:
2373     return Constant::getNullValue(Ty);
2374   }
2375 }
2376
2377 /// Remove the constant from the constant table.
2378 void ConstantExpr::destroyConstantImpl() {
2379   getType()->getContext().pImpl->ExprConstants.remove(this);
2380 }
2381
2382 const char *ConstantExpr::getOpcodeName() const {
2383   return Instruction::getOpcodeName(getOpcode());
2384 }
2385
2386 GetElementPtrConstantExpr::GetElementPtrConstantExpr(
2387     Type *SrcElementTy, Constant *C, ArrayRef<Constant *> IdxList, Type *DestTy)
2388     : ConstantExpr(DestTy, Instruction::GetElementPtr,
2389                    OperandTraits<GetElementPtrConstantExpr>::op_end(this) -
2390                        (IdxList.size() + 1),
2391                    IdxList.size() + 1),
2392       SrcElementTy(SrcElementTy),
2393       ResElementTy(GetElementPtrInst::getIndexedType(SrcElementTy, IdxList)) {
2394   Op<0>() = C;
2395   Use *OperandList = getOperandList();
2396   for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
2397     OperandList[i+1] = IdxList[i];
2398 }
2399
2400 Type *GetElementPtrConstantExpr::getSourceElementType() const {
2401   return SrcElementTy;
2402 }
2403
2404 Type *GetElementPtrConstantExpr::getResultElementType() const {
2405   return ResElementTy;
2406 }
2407
2408 //===----------------------------------------------------------------------===//
2409 //                       ConstantData* implementations
2410
2411 Type *ConstantDataSequential::getElementType() const {
2412   return getType()->getElementType();
2413 }
2414
2415 StringRef ConstantDataSequential::getRawDataValues() const {
2416   return StringRef(DataElements, getNumElements()*getElementByteSize());
2417 }
2418
2419 bool ConstantDataSequential::isElementTypeCompatible(Type *Ty) {
2420   if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) return true;
2421   if (auto *IT = dyn_cast<IntegerType>(Ty)) {
2422     switch (IT->getBitWidth()) {
2423     case 8:
2424     case 16:
2425     case 32:
2426     case 64:
2427       return true;
2428     default: break;
2429     }
2430   }
2431   return false;
2432 }
2433
2434 unsigned ConstantDataSequential::getNumElements() const {
2435   if (ArrayType *AT = dyn_cast<ArrayType>(getType()))
2436     return AT->getNumElements();
2437   return getType()->getVectorNumElements();
2438 }
2439
2440
2441 uint64_t ConstantDataSequential::getElementByteSize() const {
2442   return getElementType()->getPrimitiveSizeInBits()/8;
2443 }
2444
2445 /// Return the start of the specified element.
2446 const char *ConstantDataSequential::getElementPointer(unsigned Elt) const {
2447   assert(Elt < getNumElements() && "Invalid Elt");
2448   return DataElements+Elt*getElementByteSize();
2449 }
2450
2451
2452 /// Return true if the array is empty or all zeros.
2453 static bool isAllZeros(StringRef Arr) {
2454   for (char I : Arr)
2455     if (I != 0)
2456       return false;
2457   return true;
2458 }
2459
2460 /// This is the underlying implementation of all of the
2461 /// ConstantDataSequential::get methods.  They all thunk down to here, providing
2462 /// the correct element type.  We take the bytes in as a StringRef because
2463 /// we *want* an underlying "char*" to avoid TBAA type punning violations.
2464 Constant *ConstantDataSequential::getImpl(StringRef Elements, Type *Ty) {
2465   assert(isElementTypeCompatible(Ty->getSequentialElementType()));
2466   // If the elements are all zero or there are no elements, return a CAZ, which
2467   // is more dense and canonical.
2468   if (isAllZeros(Elements))
2469     return ConstantAggregateZero::get(Ty);
2470
2471   // Do a lookup to see if we have already formed one of these.
2472   auto &Slot =
2473       *Ty->getContext()
2474            .pImpl->CDSConstants.insert(std::make_pair(Elements, nullptr))
2475            .first;
2476
2477   // The bucket can point to a linked list of different CDS's that have the same
2478   // body but different types.  For example, 0,0,0,1 could be a 4 element array
2479   // of i8, or a 1-element array of i32.  They'll both end up in the same
2480   /// StringMap bucket, linked up by their Next pointers.  Walk the list.
2481   ConstantDataSequential **Entry = &Slot.second;
2482   for (ConstantDataSequential *Node = *Entry; Node;
2483        Entry = &Node->Next, Node = *Entry)
2484     if (Node->getType() == Ty)
2485       return Node;
2486
2487   // Okay, we didn't get a hit.  Create a node of the right class, link it in,
2488   // and return it.
2489   if (isa<ArrayType>(Ty))
2490     return *Entry = new ConstantDataArray(Ty, Slot.first().data());
2491
2492   assert(isa<VectorType>(Ty));
2493   return *Entry = new ConstantDataVector(Ty, Slot.first().data());
2494 }
2495
2496 void ConstantDataSequential::destroyConstantImpl() {
2497   // Remove the constant from the StringMap.
2498   StringMap<ConstantDataSequential*> &CDSConstants =
2499     getType()->getContext().pImpl->CDSConstants;
2500
2501   StringMap<ConstantDataSequential*>::iterator Slot =
2502     CDSConstants.find(getRawDataValues());
2503
2504   assert(Slot != CDSConstants.end() && "CDS not found in uniquing table");
2505
2506   ConstantDataSequential **Entry = &Slot->getValue();
2507
2508   // Remove the entry from the hash table.
2509   if (!(*Entry)->Next) {
2510     // If there is only one value in the bucket (common case) it must be this
2511     // entry, and removing the entry should remove the bucket completely.
2512     assert((*Entry) == this && "Hash mismatch in ConstantDataSequential");
2513     getContext().pImpl->CDSConstants.erase(Slot);
2514   } else {
2515     // Otherwise, there are multiple entries linked off the bucket, unlink the
2516     // node we care about but keep the bucket around.
2517     for (ConstantDataSequential *Node = *Entry; ;
2518          Entry = &Node->Next, Node = *Entry) {
2519       assert(Node && "Didn't find entry in its uniquing hash table!");
2520       // If we found our entry, unlink it from the list and we're done.
2521       if (Node == this) {
2522         *Entry = Node->Next;
2523         break;
2524       }
2525     }
2526   }
2527
2528   // If we were part of a list, make sure that we don't delete the list that is
2529   // still owned by the uniquing map.
2530   Next = nullptr;
2531 }
2532
2533 /// getFP() constructors - Return a constant with array type with an element
2534 /// count and element type of float with precision matching the number of
2535 /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
2536 /// double for 64bits) Note that this can return a ConstantAggregateZero
2537 /// object.
2538 Constant *ConstantDataArray::getFP(LLVMContext &Context,
2539                                    ArrayRef<uint16_t> Elts) {
2540   Type *Ty = ArrayType::get(Type::getHalfTy(Context), Elts.size());
2541   const char *Data = reinterpret_cast<const char *>(Elts.data());
2542   return getImpl(StringRef(Data, Elts.size() * 2), Ty);
2543 }
2544 Constant *ConstantDataArray::getFP(LLVMContext &Context,
2545                                    ArrayRef<uint32_t> Elts) {
2546   Type *Ty = ArrayType::get(Type::getFloatTy(Context), Elts.size());
2547   const char *Data = reinterpret_cast<const char *>(Elts.data());
2548   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2549 }
2550 Constant *ConstantDataArray::getFP(LLVMContext &Context,
2551                                    ArrayRef<uint64_t> Elts) {
2552   Type *Ty = ArrayType::get(Type::getDoubleTy(Context), Elts.size());
2553   const char *Data = reinterpret_cast<const char *>(Elts.data());
2554   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2555 }
2556
2557 Constant *ConstantDataArray::getString(LLVMContext &Context,
2558                                        StringRef Str, bool AddNull) {
2559   if (!AddNull) {
2560     const uint8_t *Data = Str.bytes_begin();
2561     return get(Context, makeArrayRef(Data, Str.size()));
2562   }
2563
2564   SmallVector<uint8_t, 64> ElementVals;
2565   ElementVals.append(Str.begin(), Str.end());
2566   ElementVals.push_back(0);
2567   return get(Context, ElementVals);
2568 }
2569
2570 /// get() constructors - Return a constant with vector type with an element
2571 /// count and element type matching the ArrayRef passed in.  Note that this
2572 /// can return a ConstantAggregateZero object.
2573 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint8_t> Elts){
2574   Type *Ty = VectorType::get(Type::getInt8Ty(Context), Elts.size());
2575   const char *Data = reinterpret_cast<const char *>(Elts.data());
2576   return getImpl(StringRef(Data, Elts.size() * 1), Ty);
2577 }
2578 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
2579   Type *Ty = VectorType::get(Type::getInt16Ty(Context), Elts.size());
2580   const char *Data = reinterpret_cast<const char *>(Elts.data());
2581   return getImpl(StringRef(Data, Elts.size() * 2), Ty);
2582 }
2583 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
2584   Type *Ty = VectorType::get(Type::getInt32Ty(Context), Elts.size());
2585   const char *Data = reinterpret_cast<const char *>(Elts.data());
2586   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2587 }
2588 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
2589   Type *Ty = VectorType::get(Type::getInt64Ty(Context), Elts.size());
2590   const char *Data = reinterpret_cast<const char *>(Elts.data());
2591   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2592 }
2593 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<float> Elts) {
2594   Type *Ty = VectorType::get(Type::getFloatTy(Context), Elts.size());
2595   const char *Data = reinterpret_cast<const char *>(Elts.data());
2596   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2597 }
2598 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<double> Elts) {
2599   Type *Ty = VectorType::get(Type::getDoubleTy(Context), Elts.size());
2600   const char *Data = reinterpret_cast<const char *>(Elts.data());
2601   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2602 }
2603
2604 /// getFP() constructors - Return a constant with vector type with an element
2605 /// count and element type of float with the precision matching the number of
2606 /// bits in the ArrayRef passed in.  (i.e. half for 16bits, float for 32bits,
2607 /// double for 64bits) Note that this can return a ConstantAggregateZero
2608 /// object.
2609 Constant *ConstantDataVector::getFP(LLVMContext &Context,
2610                                     ArrayRef<uint16_t> Elts) {
2611   Type *Ty = VectorType::get(Type::getHalfTy(Context), Elts.size());
2612   const char *Data = reinterpret_cast<const char *>(Elts.data());
2613   return getImpl(StringRef(Data, Elts.size() * 2), Ty);
2614 }
2615 Constant *ConstantDataVector::getFP(LLVMContext &Context,
2616                                     ArrayRef<uint32_t> Elts) {
2617   Type *Ty = VectorType::get(Type::getFloatTy(Context), Elts.size());
2618   const char *Data = reinterpret_cast<const char *>(Elts.data());
2619   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2620 }
2621 Constant *ConstantDataVector::getFP(LLVMContext &Context,
2622                                     ArrayRef<uint64_t> Elts) {
2623   Type *Ty = VectorType::get(Type::getDoubleTy(Context), Elts.size());
2624   const char *Data = reinterpret_cast<const char *>(Elts.data());
2625   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2626 }
2627
2628 Constant *ConstantDataVector::getSplat(unsigned NumElts, Constant *V) {
2629   assert(isElementTypeCompatible(V->getType()) &&
2630          "Element type not compatible with ConstantData");
2631   if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
2632     if (CI->getType()->isIntegerTy(8)) {
2633       SmallVector<uint8_t, 16> Elts(NumElts, CI->getZExtValue());
2634       return get(V->getContext(), Elts);
2635     }
2636     if (CI->getType()->isIntegerTy(16)) {
2637       SmallVector<uint16_t, 16> Elts(NumElts, CI->getZExtValue());
2638       return get(V->getContext(), Elts);
2639     }
2640     if (CI->getType()->isIntegerTy(32)) {
2641       SmallVector<uint32_t, 16> Elts(NumElts, CI->getZExtValue());
2642       return get(V->getContext(), Elts);
2643     }
2644     assert(CI->getType()->isIntegerTy(64) && "Unsupported ConstantData type");
2645     SmallVector<uint64_t, 16> Elts(NumElts, CI->getZExtValue());
2646     return get(V->getContext(), Elts);
2647   }
2648
2649   if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
2650     if (CFP->getType()->isHalfTy()) {
2651       SmallVector<uint16_t, 16> Elts(
2652           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2653       return getFP(V->getContext(), Elts);
2654     }
2655     if (CFP->getType()->isFloatTy()) {
2656       SmallVector<uint32_t, 16> Elts(
2657           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2658       return getFP(V->getContext(), Elts);
2659     }
2660     if (CFP->getType()->isDoubleTy()) {
2661       SmallVector<uint64_t, 16> Elts(
2662           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2663       return getFP(V->getContext(), Elts);
2664     }
2665   }
2666   return ConstantVector::getSplat(NumElts, V);
2667 }
2668
2669
2670 uint64_t ConstantDataSequential::getElementAsInteger(unsigned Elt) const {
2671   assert(isa<IntegerType>(getElementType()) &&
2672          "Accessor can only be used when element is an integer");
2673   const char *EltPtr = getElementPointer(Elt);
2674
2675   // The data is stored in host byte order, make sure to cast back to the right
2676   // type to load with the right endianness.
2677   switch (getElementType()->getIntegerBitWidth()) {
2678   default: llvm_unreachable("Invalid bitwidth for CDS");
2679   case 8:
2680     return *reinterpret_cast<const uint8_t *>(EltPtr);
2681   case 16:
2682     return *reinterpret_cast<const uint16_t *>(EltPtr);
2683   case 32:
2684     return *reinterpret_cast<const uint32_t *>(EltPtr);
2685   case 64:
2686     return *reinterpret_cast<const uint64_t *>(EltPtr);
2687   }
2688 }
2689
2690 APInt ConstantDataSequential::getElementAsAPInt(unsigned Elt) const {
2691   assert(isa<IntegerType>(getElementType()) &&
2692          "Accessor can only be used when element is an integer");
2693   const char *EltPtr = getElementPointer(Elt);
2694
2695   // The data is stored in host byte order, make sure to cast back to the right
2696   // type to load with the right endianness.
2697   switch (getElementType()->getIntegerBitWidth()) {
2698   default: llvm_unreachable("Invalid bitwidth for CDS");
2699   case 8: {
2700     auto EltVal = *reinterpret_cast<const uint8_t *>(EltPtr);
2701     return APInt(8, EltVal);
2702   }
2703   case 16: {
2704     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
2705     return APInt(16, EltVal);
2706   }
2707   case 32: {
2708     auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
2709     return APInt(32, EltVal);
2710   }
2711   case 64: {
2712     auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
2713     return APInt(64, EltVal);
2714   }
2715   }
2716 }
2717
2718 APFloat ConstantDataSequential::getElementAsAPFloat(unsigned Elt) const {
2719   const char *EltPtr = getElementPointer(Elt);
2720
2721   switch (getElementType()->getTypeID()) {
2722   default:
2723     llvm_unreachable("Accessor can only be used when element is float/double!");
2724   case Type::HalfTyID: {
2725     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
2726     return APFloat(APFloat::IEEEhalf(), APInt(16, EltVal));
2727   }
2728   case Type::FloatTyID: {
2729     auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
2730     return APFloat(APFloat::IEEEsingle(), APInt(32, EltVal));
2731   }
2732   case Type::DoubleTyID: {
2733     auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
2734     return APFloat(APFloat::IEEEdouble(), APInt(64, EltVal));
2735   }
2736   }
2737 }
2738
2739 float ConstantDataSequential::getElementAsFloat(unsigned Elt) const {
2740   assert(getElementType()->isFloatTy() &&
2741          "Accessor can only be used when element is a 'float'");
2742   return *reinterpret_cast<const float *>(getElementPointer(Elt));
2743 }
2744
2745 double ConstantDataSequential::getElementAsDouble(unsigned Elt) const {
2746   assert(getElementType()->isDoubleTy() &&
2747          "Accessor can only be used when element is a 'float'");
2748   return *reinterpret_cast<const double *>(getElementPointer(Elt));
2749 }
2750
2751 Constant *ConstantDataSequential::getElementAsConstant(unsigned Elt) const {
2752   if (getElementType()->isHalfTy() || getElementType()->isFloatTy() ||
2753       getElementType()->isDoubleTy())
2754     return ConstantFP::get(getContext(), getElementAsAPFloat(Elt));
2755
2756   return ConstantInt::get(getElementType(), getElementAsInteger(Elt));
2757 }
2758
2759 bool ConstantDataSequential::isString(unsigned CharSize) const {
2760   return isa<ArrayType>(getType()) && getElementType()->isIntegerTy(CharSize);
2761 }
2762
2763 bool ConstantDataSequential::isCString() const {
2764   if (!isString())
2765     return false;
2766
2767   StringRef Str = getAsString();
2768
2769   // The last value must be nul.
2770   if (Str.back() != 0) return false;
2771
2772   // Other elements must be non-nul.
2773   return Str.drop_back().find(0) == StringRef::npos;
2774 }
2775
2776 bool ConstantDataVector::isSplat() const {
2777   const char *Base = getRawDataValues().data();
2778
2779   // Compare elements 1+ to the 0'th element.
2780   unsigned EltSize = getElementByteSize();
2781   for (unsigned i = 1, e = getNumElements(); i != e; ++i)
2782     if (memcmp(Base, Base+i*EltSize, EltSize))
2783       return false;
2784
2785   return true;
2786 }
2787
2788 Constant *ConstantDataVector::getSplatValue() const {
2789   // If they're all the same, return the 0th one as a representative.
2790   return isSplat() ? getElementAsConstant(0) : nullptr;
2791 }
2792
2793 //===----------------------------------------------------------------------===//
2794 //                handleOperandChange implementations
2795
2796 /// Update this constant array to change uses of
2797 /// 'From' to be uses of 'To'.  This must update the uniquing data structures
2798 /// etc.
2799 ///
2800 /// Note that we intentionally replace all uses of From with To here.  Consider
2801 /// a large array that uses 'From' 1000 times.  By handling this case all here,
2802 /// ConstantArray::handleOperandChange is only invoked once, and that
2803 /// single invocation handles all 1000 uses.  Handling them one at a time would
2804 /// work, but would be really slow because it would have to unique each updated
2805 /// array instance.
2806 ///
2807 void Constant::handleOperandChange(Value *From, Value *To) {
2808   Value *Replacement = nullptr;
2809   switch (getValueID()) {
2810   default:
2811     llvm_unreachable("Not a constant!");
2812 #define HANDLE_CONSTANT(Name)                                                  \
2813   case Value::Name##Val:                                                       \
2814     Replacement = cast<Name>(this)->handleOperandChangeImpl(From, To);         \
2815     break;
2816 #include "llvm/IR/Value.def"
2817   }
2818
2819   // If handleOperandChangeImpl returned nullptr, then it handled
2820   // replacing itself and we don't want to delete or replace anything else here.
2821   if (!Replacement)
2822     return;
2823
2824   // I do need to replace this with an existing value.
2825   assert(Replacement != this && "I didn't contain From!");
2826
2827   // Everyone using this now uses the replacement.
2828   replaceAllUsesWith(Replacement);
2829
2830   // Delete the old constant!
2831   destroyConstant();
2832 }
2833
2834 Value *ConstantArray::handleOperandChangeImpl(Value *From, Value *To) {
2835   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
2836   Constant *ToC = cast<Constant>(To);
2837
2838   SmallVector<Constant*, 8> Values;
2839   Values.reserve(getNumOperands());  // Build replacement array.
2840
2841   // Fill values with the modified operands of the constant array.  Also,
2842   // compute whether this turns into an all-zeros array.
2843   unsigned NumUpdated = 0;
2844
2845   // Keep track of whether all the values in the array are "ToC".
2846   bool AllSame = true;
2847   Use *OperandList = getOperandList();
2848   unsigned OperandNo = 0;
2849   for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
2850     Constant *Val = cast<Constant>(O->get());
2851     if (Val == From) {
2852       OperandNo = (O - OperandList);
2853       Val = ToC;
2854       ++NumUpdated;
2855     }
2856     Values.push_back(Val);
2857     AllSame &= Val == ToC;
2858   }
2859
2860   if (AllSame && ToC->isNullValue())
2861     return ConstantAggregateZero::get(getType());
2862
2863   if (AllSame && isa<UndefValue>(ToC))
2864     return UndefValue::get(getType());
2865
2866   // Check for any other type of constant-folding.
2867   if (Constant *C = getImpl(getType(), Values))
2868     return C;
2869
2870   // Update to the new value.
2871   return getContext().pImpl->ArrayConstants.replaceOperandsInPlace(
2872       Values, this, From, ToC, NumUpdated, OperandNo);
2873 }
2874
2875 Value *ConstantStruct::handleOperandChangeImpl(Value *From, Value *To) {
2876   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
2877   Constant *ToC = cast<Constant>(To);
2878
2879   Use *OperandList = getOperandList();
2880
2881   SmallVector<Constant*, 8> Values;
2882   Values.reserve(getNumOperands());  // Build replacement struct.
2883
2884   // Fill values with the modified operands of the constant struct.  Also,
2885   // compute whether this turns into an all-zeros struct.
2886   unsigned NumUpdated = 0;
2887   bool AllSame = true;
2888   unsigned OperandNo = 0;
2889   for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O) {
2890     Constant *Val = cast<Constant>(O->get());
2891     if (Val == From) {
2892       OperandNo = (O - OperandList);
2893       Val = ToC;
2894       ++NumUpdated;
2895     }
2896     Values.push_back(Val);
2897     AllSame &= Val == ToC;
2898   }
2899
2900   if (AllSame && ToC->isNullValue())
2901     return ConstantAggregateZero::get(getType());
2902
2903   if (AllSame && isa<UndefValue>(ToC))
2904     return UndefValue::get(getType());
2905
2906   // Update to the new value.
2907   return getContext().pImpl->StructConstants.replaceOperandsInPlace(
2908       Values, this, From, ToC, NumUpdated, OperandNo);
2909 }
2910
2911 Value *ConstantVector::handleOperandChangeImpl(Value *From, Value *To) {
2912   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
2913   Constant *ToC = cast<Constant>(To);
2914
2915   SmallVector<Constant*, 8> Values;
2916   Values.reserve(getNumOperands());  // Build replacement array...
2917   unsigned NumUpdated = 0;
2918   unsigned OperandNo = 0;
2919   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2920     Constant *Val = getOperand(i);
2921     if (Val == From) {
2922       OperandNo = i;
2923       ++NumUpdated;
2924       Val = ToC;
2925     }
2926     Values.push_back(Val);
2927   }
2928
2929   if (Constant *C = getImpl(Values))
2930     return C;
2931
2932   // Update to the new value.
2933   return getContext().pImpl->VectorConstants.replaceOperandsInPlace(
2934       Values, this, From, ToC, NumUpdated, OperandNo);
2935 }
2936
2937 Value *ConstantExpr::handleOperandChangeImpl(Value *From, Value *ToV) {
2938   assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
2939   Constant *To = cast<Constant>(ToV);
2940
2941   SmallVector<Constant*, 8> NewOps;
2942   unsigned NumUpdated = 0;
2943   unsigned OperandNo = 0;
2944   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2945     Constant *Op = getOperand(i);
2946     if (Op == From) {
2947       OperandNo = i;
2948       ++NumUpdated;
2949       Op = To;
2950     }
2951     NewOps.push_back(Op);
2952   }
2953   assert(NumUpdated && "I didn't contain From!");
2954
2955   if (Constant *C = getWithOperands(NewOps, getType(), true))
2956     return C;
2957
2958   // Update to the new value.
2959   return getContext().pImpl->ExprConstants.replaceOperandsInPlace(
2960       NewOps, this, From, To, NumUpdated, OperandNo);
2961 }
2962
2963 Instruction *ConstantExpr::getAsInstruction() {
2964   SmallVector<Value *, 4> ValueOperands(op_begin(), op_end());
2965   ArrayRef<Value*> Ops(ValueOperands);
2966
2967   switch (getOpcode()) {
2968   case Instruction::Trunc:
2969   case Instruction::ZExt:
2970   case Instruction::SExt:
2971   case Instruction::FPTrunc:
2972   case Instruction::FPExt:
2973   case Instruction::UIToFP:
2974   case Instruction::SIToFP:
2975   case Instruction::FPToUI:
2976   case Instruction::FPToSI:
2977   case Instruction::PtrToInt:
2978   case Instruction::IntToPtr:
2979   case Instruction::BitCast:
2980   case Instruction::AddrSpaceCast:
2981     return CastInst::Create((Instruction::CastOps)getOpcode(),
2982                             Ops[0], getType());
2983   case Instruction::Select:
2984     return SelectInst::Create(Ops[0], Ops[1], Ops[2]);
2985   case Instruction::InsertElement:
2986     return InsertElementInst::Create(Ops[0], Ops[1], Ops[2]);
2987   case Instruction::ExtractElement:
2988     return ExtractElementInst::Create(Ops[0], Ops[1]);
2989   case Instruction::InsertValue:
2990     return InsertValueInst::Create(Ops[0], Ops[1], getIndices());
2991   case Instruction::ExtractValue:
2992     return ExtractValueInst::Create(Ops[0], getIndices());
2993   case Instruction::ShuffleVector:
2994     return new ShuffleVectorInst(Ops[0], Ops[1], Ops[2]);
2995
2996   case Instruction::GetElementPtr: {
2997     const auto *GO = cast<GEPOperator>(this);
2998     if (GO->isInBounds())
2999       return GetElementPtrInst::CreateInBounds(GO->getSourceElementType(),
3000                                                Ops[0], Ops.slice(1));
3001     return GetElementPtrInst::Create(GO->getSourceElementType(), Ops[0],
3002                                      Ops.slice(1));
3003   }
3004   case Instruction::ICmp:
3005   case Instruction::FCmp:
3006     return CmpInst::Create((Instruction::OtherOps)getOpcode(),
3007                            (CmpInst::Predicate)getPredicate(), Ops[0], Ops[1]);
3008   case Instruction::FNeg:
3009     return UnaryOperator::Create((Instruction::UnaryOps)getOpcode(), Ops[0]);
3010   default:
3011     assert(getNumOperands() == 2 && "Must be binary operator?");
3012     BinaryOperator *BO =
3013       BinaryOperator::Create((Instruction::BinaryOps)getOpcode(),
3014                              Ops[0], Ops[1]);
3015     if (isa<OverflowingBinaryOperator>(BO)) {
3016       BO->setHasNoUnsignedWrap(SubclassOptionalData &
3017                                OverflowingBinaryOperator::NoUnsignedWrap);
3018       BO->setHasNoSignedWrap(SubclassOptionalData &
3019                              OverflowingBinaryOperator::NoSignedWrap);
3020     }
3021     if (isa<PossiblyExactOperator>(BO))
3022       BO->setIsExact(SubclassOptionalData & PossiblyExactOperator::IsExact);
3023     return BO;
3024   }
3025 }