lib/IR/Constants.cpp

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