llvm/lib/IR/Constants.cpp

   1 //===-- Constants.cpp - Implement Constant nodes --------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the Constant* classes.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/IR/Constants.h"
  14 #include "LLVMContextImpl.h"
  15 #include "llvm/ADT/STLExtras.h"
  16 #include "llvm/ADT/SmallVector.h"
  17 #include "llvm/ADT/StringMap.h"
  18 #include "llvm/IR/BasicBlock.h"
  19 #include "llvm/IR/ConstantFold.h"
  20 #include "llvm/IR/DerivedTypes.h"
  21 #include "llvm/IR/Function.h"
  22 #include "llvm/IR/GetElementPtrTypeIterator.h"
  23 #include "llvm/IR/GlobalAlias.h"
  24 #include "llvm/IR/GlobalIFunc.h"
  25 #include "llvm/IR/GlobalValue.h"
  26 #include "llvm/IR/GlobalVariable.h"
  27 #include "llvm/IR/Instructions.h"
  28 #include "llvm/IR/Operator.h"
  29 #include "llvm/IR/PatternMatch.h"
  30 #include "llvm/Support/ErrorHandling.h"
  31 #include "llvm/Support/MathExtras.h"
  32 #include "llvm/Support/raw_ostream.h"
  33 #include <algorithm>
  34
  35 using namespace llvm;
  36 using namespace PatternMatch;
  37
  38 //===----------------------------------------------------------------------===//
  39 //                              Constant Class
  40 //===----------------------------------------------------------------------===//
  41
  42 bool Constant::isNegativeZeroValue() const {
  43   // Floating point values have an explicit -0.0 value.
  44   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
  45     return CFP->isZero() && CFP->isNegative();
  46
  47   // Equivalent for a vector of -0.0's.
  48   if (getType()->isVectorTy())
  49     if (const auto *SplatCFP = dyn_cast_or_null<ConstantFP>(getSplatValue()))
  50       return SplatCFP->isNegativeZeroValue();
  51
  52   // We've already handled true FP case; any other FP vectors can't represent -0.0.
  53   if (getType()->isFPOrFPVectorTy())
  54     return false;
  55
  56   // Otherwise, just use +0.0.
  57   return isNullValue();
  58 }
  59
  60 // Return true iff this constant is positive zero (floating point), negative
  61 // zero (floating point), or a null value.
  62 bool Constant::isZeroValue() const {
  63   // Floating point values have an explicit -0.0 value.
  64   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
  65     return CFP->isZero();
  66
  67   // Check for constant splat vectors of 1 values.
  68   if (getType()->isVectorTy())
  69     if (const auto *SplatCFP = dyn_cast_or_null<ConstantFP>(getSplatValue()))
  70       return SplatCFP->isZero();
  71
  72   // Otherwise, just use +0.0.
  73   return isNullValue();
  74 }
  75
  76 bool Constant::isNullValue() const {
  77   // 0 is null.
  78   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
  79     return CI->isZero();
  80
  81   // +0.0 is null.
  82   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
  83     // ppc_fp128 determine isZero using high order double only
  84     // Should check the bitwise value to make sure all bits are zero.
  85     return CFP->isExactlyValue(+0.0);
  86
  87   // constant zero is zero for aggregates, cpnull is null for pointers, none for
  88   // tokens.
  89   return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this) ||
  90          isa<ConstantTokenNone>(this) || isa<ConstantTargetNone>(this);
  91 }
  92
  93 bool Constant::isAllOnesValue() const {
  94   // Check for -1 integers
  95   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
  96     return CI->isMinusOne();
  97
  98   // Check for FP which are bitcasted from -1 integers
  99   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 100     return CFP->getValueAPF().bitcastToAPInt().isAllOnes();
 101
 102   // Check for constant splat vectors of 1 values.
 103   if (getType()->isVectorTy())
 104     if (const auto *SplatVal = getSplatValue())
 105       return SplatVal->isAllOnesValue();
 106
 107   return false;
 108 }
 109
 110 bool Constant::isOneValue() const {
 111   // Check for 1 integers
 112   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 113     return CI->isOne();
 114
 115   // Check for FP which are bitcasted from 1 integers
 116   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 117     return CFP->getValueAPF().bitcastToAPInt().isOne();
 118
 119   // Check for constant splat vectors of 1 values.
 120   if (getType()->isVectorTy())
 121     if (const auto *SplatVal = getSplatValue())
 122       return SplatVal->isOneValue();
 123
 124   return false;
 125 }
 126
 127 bool Constant::isNotOneValue() const {
 128   // Check for 1 integers
 129   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 130     return !CI->isOneValue();
 131
 132   // Check for FP which are bitcasted from 1 integers
 133   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 134     return !CFP->getValueAPF().bitcastToAPInt().isOne();
 135
 136   // Check that vectors don't contain 1
 137   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 138     for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
 139       Constant *Elt = getAggregateElement(I);
 140       if (!Elt || !Elt->isNotOneValue())
 141         return false;
 142     }
 143     return true;
 144   }
 145
 146   // Check for splats that don't contain 1
 147   if (getType()->isVectorTy())
 148     if (const auto *SplatVal = getSplatValue())
 149       return SplatVal->isNotOneValue();
 150
 151   // It *may* contain 1, we can't tell.
 152   return false;
 153 }
 154
 155 bool Constant::isMinSignedValue() const {
 156   // Check for INT_MIN integers
 157   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 158     return CI->isMinValue(/*isSigned=*/true);
 159
 160   // Check for FP which are bitcasted from INT_MIN integers
 161   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 162     return CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
 163
 164   // Check for splats of INT_MIN values.
 165   if (getType()->isVectorTy())
 166     if (const auto *SplatVal = getSplatValue())
 167       return SplatVal->isMinSignedValue();
 168
 169   return false;
 170 }
 171
 172 bool Constant::isNotMinSignedValue() const {
 173   // Check for INT_MIN integers
 174   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
 175     return !CI->isMinValue(/*isSigned=*/true);
 176
 177   // Check for FP which are bitcasted from INT_MIN integers
 178   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
 179     return !CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
 180
 181   // Check that vectors don't contain INT_MIN
 182   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 183     for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
 184       Constant *Elt = getAggregateElement(I);
 185       if (!Elt || !Elt->isNotMinSignedValue())
 186         return false;
 187     }
 188     return true;
 189   }
 190
 191   // Check for splats that aren't INT_MIN
 192   if (getType()->isVectorTy())
 193     if (const auto *SplatVal = getSplatValue())
 194       return SplatVal->isNotMinSignedValue();
 195
 196   // It *may* contain INT_MIN, we can't tell.
 197   return false;
 198 }
 199
 200 bool Constant::isFiniteNonZeroFP() const {
 201   if (auto *CFP = dyn_cast<ConstantFP>(this))
 202     return CFP->getValueAPF().isFiniteNonZero();
 203
 204   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 205     for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
 206       auto *CFP = dyn_cast_or_null<ConstantFP>(getAggregateElement(I));
 207       if (!CFP || !CFP->getValueAPF().isFiniteNonZero())
 208         return false;
 209     }
 210     return true;
 211   }
 212
 213   if (getType()->isVectorTy())
 214     if (const auto *SplatCFP = dyn_cast_or_null<ConstantFP>(getSplatValue()))
 215       return SplatCFP->isFiniteNonZeroFP();
 216
 217   // It *may* contain finite non-zero, we can't tell.
 218   return false;
 219 }
 220
 221 bool Constant::isNormalFP() const {
 222   if (auto *CFP = dyn_cast<ConstantFP>(this))
 223     return CFP->getValueAPF().isNormal();
 224
 225   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 226     for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
 227       auto *CFP = dyn_cast_or_null<ConstantFP>(getAggregateElement(I));
 228       if (!CFP || !CFP->getValueAPF().isNormal())
 229         return false;
 230     }
 231     return true;
 232   }
 233
 234   if (getType()->isVectorTy())
 235     if (const auto *SplatCFP = dyn_cast_or_null<ConstantFP>(getSplatValue()))
 236       return SplatCFP->isNormalFP();
 237
 238   // It *may* contain a normal fp value, we can't tell.
 239   return false;
 240 }
 241
 242 bool Constant::hasExactInverseFP() const {
 243   if (auto *CFP = dyn_cast<ConstantFP>(this))
 244     return CFP->getValueAPF().getExactInverse(nullptr);
 245
 246   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 247     for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
 248       auto *CFP = dyn_cast_or_null<ConstantFP>(getAggregateElement(I));
 249       if (!CFP || !CFP->getValueAPF().getExactInverse(nullptr))
 250         return false;
 251     }
 252     return true;
 253   }
 254
 255   if (getType()->isVectorTy())
 256     if (const auto *SplatCFP = dyn_cast_or_null<ConstantFP>(getSplatValue()))
 257       return SplatCFP->hasExactInverseFP();
 258
 259   // It *may* have an exact inverse fp value, we can't tell.
 260   return false;
 261 }
 262
 263 bool Constant::isNaN() const {
 264   if (auto *CFP = dyn_cast<ConstantFP>(this))
 265     return CFP->isNaN();
 266
 267   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 268     for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
 269       auto *CFP = dyn_cast_or_null<ConstantFP>(getAggregateElement(I));
 270       if (!CFP || !CFP->isNaN())
 271         return false;
 272     }
 273     return true;
 274   }
 275
 276   if (getType()->isVectorTy())
 277     if (const auto *SplatCFP = dyn_cast_or_null<ConstantFP>(getSplatValue()))
 278       return SplatCFP->isNaN();
 279
 280   // It *may* be NaN, we can't tell.
 281   return false;
 282 }
 283
 284 bool Constant::isElementWiseEqual(Value *Y) const {
 285   // Are they fully identical?
 286   if (this == Y)
 287     return true;
 288
 289   // The input value must be a vector constant with the same type.
 290   auto *VTy = dyn_cast<VectorType>(getType());
 291   if (!isa<Constant>(Y) || !VTy || VTy != Y->getType())
 292     return false;
 293
 294   // TODO: Compare pointer constants?
 295   if (!(VTy->getElementType()->isIntegerTy() ||
 296         VTy->getElementType()->isFloatingPointTy()))
 297     return false;
 298
 299   // They may still be identical element-wise (if they have `undef`s).
 300   // Bitcast to integer to allow exact bitwise comparison for all types.
 301   Type *IntTy = VectorType::getInteger(VTy);
 302   Constant *C0 = ConstantExpr::getBitCast(const_cast<Constant *>(this), IntTy);
 303   Constant *C1 = ConstantExpr::getBitCast(cast<Constant>(Y), IntTy);
 304   Constant *CmpEq = ConstantExpr::getICmp(ICmpInst::ICMP_EQ, C0, C1);
 305   return isa<UndefValue>(CmpEq) || match(CmpEq, m_One());
 306 }
 307
 308 static bool
 309 containsUndefinedElement(const Constant *C,
 310                          function_ref<bool(const Constant *)> HasFn) {
 311   if (auto *VTy = dyn_cast<VectorType>(C->getType())) {
 312     if (HasFn(C))
 313       return true;
 314     if (isa<ConstantAggregateZero>(C))
 315       return false;
 316     if (isa<ScalableVectorType>(C->getType()))
 317       return false;
 318
 319     for (unsigned i = 0, e = cast<FixedVectorType>(VTy)->getNumElements();
 320          i != e; ++i) {
 321       if (Constant *Elem = C->getAggregateElement(i))
 322         if (HasFn(Elem))
 323           return true;
 324     }
 325   }
 326
 327   return false;
 328 }
 329
 330 bool Constant::containsUndefOrPoisonElement() const {
 331   return containsUndefinedElement(
 332       this, [&](const auto *C) { return isa<UndefValue>(C); });
 333 }
 334
 335 bool Constant::containsPoisonElement() const {
 336   return containsUndefinedElement(
 337       this, [&](const auto *C) { return isa<PoisonValue>(C); });
 338 }
 339
 340 bool Constant::containsUndefElement() const {
 341   return containsUndefinedElement(this, [&](const auto *C) {
 342     return isa<UndefValue>(C) && !isa<PoisonValue>(C);
 343   });
 344 }
 345
 346 bool Constant::containsConstantExpression() const {
 347   if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
 348     for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i)
 349       if (isa<ConstantExpr>(getAggregateElement(i)))
 350         return true;
 351   }
 352   return false;
 353 }
 354
 355 /// Constructor to create a '0' constant of arbitrary type.
 356 Constant *Constant::getNullValue(Type *Ty) {
 357   switch (Ty->getTypeID()) {
 358   case Type::IntegerTyID:
 359     return ConstantInt::get(Ty, 0);
 360   case Type::HalfTyID:
 361   case Type::BFloatTyID:
 362   case Type::FloatTyID:
 363   case Type::DoubleTyID:
 364   case Type::X86_FP80TyID:
 365   case Type::FP128TyID:
 366   case Type::PPC_FP128TyID:
 367     return ConstantFP::get(Ty->getContext(),
 368                            APFloat::getZero(Ty->getFltSemantics()));
 369   case Type::PointerTyID:
 370     return ConstantPointerNull::get(cast<PointerType>(Ty));
 371   case Type::StructTyID:
 372   case Type::ArrayTyID:
 373   case Type::FixedVectorTyID:
 374   case Type::ScalableVectorTyID:
 375     return ConstantAggregateZero::get(Ty);
 376   case Type::TokenTyID:
 377     return ConstantTokenNone::get(Ty->getContext());
 378   case Type::TargetExtTyID:
 379     return ConstantTargetNone::get(cast<TargetExtType>(Ty));
 380   default:
 381     // Function, Label, or Opaque type?
 382     llvm_unreachable("Cannot create a null constant of that type!");
 383   }
 384 }
 385
 386 Constant *Constant::getIntegerValue(Type *Ty, const APInt &V) {
 387   Type *ScalarTy = Ty->getScalarType();
 388
 389   // Create the base integer constant.
 390   Constant *C = ConstantInt::get(Ty->getContext(), V);
 391
 392   // Convert an integer to a pointer, if necessary.
 393   if (PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
 394     C = ConstantExpr::getIntToPtr(C, PTy);
 395
 396   // Broadcast a scalar to a vector, if necessary.
 397   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 398     C = ConstantVector::getSplat(VTy->getElementCount(), C);
 399
 400   return C;
 401 }
 402
 403 Constant *Constant::getAllOnesValue(Type *Ty) {
 404   if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
 405     return ConstantInt::get(Ty->getContext(),
 406                             APInt::getAllOnes(ITy->getBitWidth()));
 407
 408   if (Ty->isFloatingPointTy()) {
 409     APFloat FL = APFloat::getAllOnesValue(Ty->getFltSemantics());
 410     return ConstantFP::get(Ty->getContext(), FL);
 411   }
 412
 413   VectorType *VTy = cast<VectorType>(Ty);
 414   return ConstantVector::getSplat(VTy->getElementCount(),
 415                                   getAllOnesValue(VTy->getElementType()));
 416 }
 417
 418 Constant *Constant::getAggregateElement(unsigned Elt) const {
 419   assert((getType()->isAggregateType() || getType()->isVectorTy()) &&
 420          "Must be an aggregate/vector constant");
 421
 422   if (const auto *CC = dyn_cast<ConstantAggregate>(this))
 423     return Elt < CC->getNumOperands() ? CC->getOperand(Elt) : nullptr;
 424
 425   if (const auto *CAZ = dyn_cast<ConstantAggregateZero>(this))
 426     return Elt < CAZ->getElementCount().getKnownMinValue()
 427                ? CAZ->getElementValue(Elt)
 428                : nullptr;
 429
 430   // FIXME: getNumElements() will fail for non-fixed vector types.
 431   if (isa<ScalableVectorType>(getType()))
 432     return nullptr;
 433
 434   if (const auto *PV = dyn_cast<PoisonValue>(this))
 435     return Elt < PV->getNumElements() ? PV->getElementValue(Elt) : nullptr;
 436
 437   if (const auto *UV = dyn_cast<UndefValue>(this))
 438     return Elt < UV->getNumElements() ? UV->getElementValue(Elt) : nullptr;
 439
 440   if (const auto *CDS = dyn_cast<ConstantDataSequential>(this))
 441     return Elt < CDS->getNumElements() ? CDS->getElementAsConstant(Elt)
 442                                        : nullptr;
 443
 444   return nullptr;
 445 }
 446
 447 Constant *Constant::getAggregateElement(Constant *Elt) const {
 448   assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer");
 449   if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt)) {
 450     // Check if the constant fits into an uint64_t.
 451     if (CI->getValue().getActiveBits() > 64)
 452       return nullptr;
 453     return getAggregateElement(CI->getZExtValue());
 454   }
 455   return nullptr;
 456 }
 457
 458 void Constant::destroyConstant() {
 459   /// First call destroyConstantImpl on the subclass.  This gives the subclass
 460   /// a chance to remove the constant from any maps/pools it's contained in.
 461   switch (getValueID()) {
 462   default:
 463     llvm_unreachable("Not a constant!");
 464 #define HANDLE_CONSTANT(Name)                                                  \
 465   case Value::Name##Val:                                                       \
 466     cast<Name>(this)->destroyConstantImpl();                                   \
 467     break;
 468 #include "llvm/IR/Value.def"
 469   }
 470
 471   // When a Constant is destroyed, there may be lingering
 472   // references to the constant by other constants in the constant pool.  These
 473   // constants are implicitly dependent on the module that is being deleted,
 474   // but they don't know that.  Because we only find out when the CPV is
 475   // deleted, we must now notify all of our users (that should only be
 476   // Constants) that they are, in fact, invalid now and should be deleted.
 477   //
 478   while (!use_empty()) {
 479     Value *V = user_back();
 480 #ifndef NDEBUG // Only in -g mode...
 481     if (!isa<Constant>(V)) {
 482       dbgs() << "While deleting: " << *this
 483              << "\n\nUse still stuck around after Def is destroyed: " << *V
 484              << "\n\n";
 485     }
 486 #endif
 487     assert(isa<Constant>(V) && "References remain to Constant being destroyed");
 488     cast<Constant>(V)->destroyConstant();
 489
 490     // The constant should remove itself from our use list...
 491     assert((use_empty() || user_back() != V) && "Constant not removed!");
 492   }
 493
 494   // Value has no outstanding references it is safe to delete it now...
 495   deleteConstant(this);
 496 }
 497
 498 void llvm::deleteConstant(Constant *C) {
 499   switch (C->getValueID()) {
 500   case Constant::ConstantIntVal:
 501     delete static_cast<ConstantInt *>(C);
 502     break;
 503   case Constant::ConstantFPVal:
 504     delete static_cast<ConstantFP *>(C);
 505     break;
 506   case Constant::ConstantAggregateZeroVal:
 507     delete static_cast<ConstantAggregateZero *>(C);
 508     break;
 509   case Constant::ConstantArrayVal:
 510     delete static_cast<ConstantArray *>(C);
 511     break;
 512   case Constant::ConstantStructVal:
 513     delete static_cast<ConstantStruct *>(C);
 514     break;
 515   case Constant::ConstantVectorVal:
 516     delete static_cast<ConstantVector *>(C);
 517     break;
 518   case Constant::ConstantPointerNullVal:
 519     delete static_cast<ConstantPointerNull *>(C);
 520     break;
 521   case Constant::ConstantDataArrayVal:
 522     delete static_cast<ConstantDataArray *>(C);
 523     break;
 524   case Constant::ConstantDataVectorVal:
 525     delete static_cast<ConstantDataVector *>(C);
 526     break;
 527   case Constant::ConstantTokenNoneVal:
 528     delete static_cast<ConstantTokenNone *>(C);
 529     break;
 530   case Constant::BlockAddressVal:
 531     delete static_cast<BlockAddress *>(C);
 532     break;
 533   case Constant::DSOLocalEquivalentVal:
 534     delete static_cast<DSOLocalEquivalent *>(C);
 535     break;
 536   case Constant::NoCFIValueVal:
 537     delete static_cast<NoCFIValue *>(C);
 538     break;
 539   case Constant::UndefValueVal:
 540     delete static_cast<UndefValue *>(C);
 541     break;
 542   case Constant::PoisonValueVal:
 543     delete static_cast<PoisonValue *>(C);
 544     break;
 545   case Constant::ConstantExprVal:
 546     if (isa<CastConstantExpr>(C))
 547       delete static_cast<CastConstantExpr *>(C);
 548     else if (isa<BinaryConstantExpr>(C))
 549       delete static_cast<BinaryConstantExpr *>(C);
 550     else if (isa<ExtractElementConstantExpr>(C))
 551       delete static_cast<ExtractElementConstantExpr *>(C);
 552     else if (isa<InsertElementConstantExpr>(C))
 553       delete static_cast<InsertElementConstantExpr *>(C);
 554     else if (isa<ShuffleVectorConstantExpr>(C))
 555       delete static_cast<ShuffleVectorConstantExpr *>(C);
 556     else if (isa<GetElementPtrConstantExpr>(C))
 557       delete static_cast<GetElementPtrConstantExpr *>(C);
 558     else if (isa<CompareConstantExpr>(C))
 559       delete static_cast<CompareConstantExpr *>(C);
 560     else
 561       llvm_unreachable("Unexpected constant expr");
 562     break;
 563   default:
 564     llvm_unreachable("Unexpected constant");
 565   }
 566 }
 567
 568 /// Check if C contains a GlobalValue for which Predicate is true.
 569 static bool
 570 ConstHasGlobalValuePredicate(const Constant *C,
 571                              bool (*Predicate)(const GlobalValue *)) {
 572   SmallPtrSet<const Constant *, 8> Visited;
 573   SmallVector<const Constant *, 8> WorkList;
 574   WorkList.push_back(C);
 575   Visited.insert(C);
 576
 577   while (!WorkList.empty()) {
 578     const Constant *WorkItem = WorkList.pop_back_val();
 579     if (const auto *GV = dyn_cast<GlobalValue>(WorkItem))
 580       if (Predicate(GV))
 581         return true;
 582     for (const Value *Op : WorkItem->operands()) {
 583       const Constant *ConstOp = dyn_cast<Constant>(Op);
 584       if (!ConstOp)
 585         continue;
 586       if (Visited.insert(ConstOp).second)
 587         WorkList.push_back(ConstOp);
 588     }
 589   }
 590   return false;
 591 }
 592
 593 bool Constant::isThreadDependent() const {
 594   auto DLLImportPredicate = [](const GlobalValue *GV) {
 595     return GV->isThreadLocal();
 596   };
 597   return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
 598 }
 599
 600 bool Constant::isDLLImportDependent() const {
 601   auto DLLImportPredicate = [](const GlobalValue *GV) {
 602     return GV->hasDLLImportStorageClass();
 603   };
 604   return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
 605 }
 606
 607 bool Constant::isConstantUsed() const {
 608   for (const User *U : users()) {
 609     const Constant *UC = dyn_cast<Constant>(U);
 610     if (!UC || isa<GlobalValue>(UC))
 611       return true;
 612
 613     if (UC->isConstantUsed())
 614       return true;
 615   }
 616   return false;
 617 }
 618
 619 bool Constant::needsDynamicRelocation() const {
 620   return getRelocationInfo() == GlobalRelocation;
 621 }
 622
 623 bool Constant::needsRelocation() const {
 624   return getRelocationInfo() != NoRelocation;
 625 }
 626
 627 Constant::PossibleRelocationsTy Constant::getRelocationInfo() const {
 628   if (isa<GlobalValue>(this))
 629     return GlobalRelocation; // Global reference.
 630
 631   if (const BlockAddress *BA = dyn_cast<BlockAddress>(this))
 632     return BA->getFunction()->getRelocationInfo();
 633
 634   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(this)) {
 635     if (CE->getOpcode() == Instruction::Sub) {
 636       ConstantExpr *LHS = dyn_cast<ConstantExpr>(CE->getOperand(0));
 637       ConstantExpr *RHS = dyn_cast<ConstantExpr>(CE->getOperand(1));
 638       if (LHS && RHS && LHS->getOpcode() == Instruction::PtrToInt &&
 639           RHS->getOpcode() == Instruction::PtrToInt) {
 640         Constant *LHSOp0 = LHS->getOperand(0);
 641         Constant *RHSOp0 = RHS->getOperand(0);
 642
 643         // While raw uses of blockaddress need to be relocated, differences
 644         // between two of them don't when they are for labels in the same
 645         // function.  This is a common idiom when creating a table for the
 646         // indirect goto extension, so we handle it efficiently here.
 647         if (isa<BlockAddress>(LHSOp0) && isa<BlockAddress>(RHSOp0) &&
 648             cast<BlockAddress>(LHSOp0)->getFunction() ==
 649                 cast<BlockAddress>(RHSOp0)->getFunction())
 650           return NoRelocation;
 651
 652         // Relative pointers do not need to be dynamically relocated.
 653         if (auto *RHSGV =
 654                 dyn_cast<GlobalValue>(RHSOp0->stripInBoundsConstantOffsets())) {
 655           auto *LHS = LHSOp0->stripInBoundsConstantOffsets();
 656           if (auto *LHSGV = dyn_cast<GlobalValue>(LHS)) {
 657             if (LHSGV->isDSOLocal() && RHSGV->isDSOLocal())
 658               return LocalRelocation;
 659           } else if (isa<DSOLocalEquivalent>(LHS)) {
 660             if (RHSGV->isDSOLocal())
 661               return LocalRelocation;
 662           }
 663         }
 664       }
 665     }
 666   }
 667
 668   PossibleRelocationsTy Result = NoRelocation;
 669   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 670     Result =
 671         std::max(cast<Constant>(getOperand(i))->getRelocationInfo(), Result);
 672
 673   return Result;
 674 }
 675
 676 /// Return true if the specified constantexpr is dead. This involves
 677 /// recursively traversing users of the constantexpr.
 678 /// If RemoveDeadUsers is true, also remove dead users at the same time.
 679 static bool constantIsDead(const Constant *C, bool RemoveDeadUsers) {
 680   if (isa<GlobalValue>(C)) return false; // Cannot remove this
 681
 682   Value::const_user_iterator I = C->user_begin(), E = C->user_end();
 683   while (I != E) {
 684     const Constant *User = dyn_cast<Constant>(*I);
 685     if (!User) return false; // Non-constant usage;
 686     if (!constantIsDead(User, RemoveDeadUsers))
 687       return false; // Constant wasn't dead
 688
 689     // Just removed User, so the iterator was invalidated.
 690     // Since we return immediately upon finding a live user, we can always
 691     // restart from user_begin().
 692     if (RemoveDeadUsers)
 693       I = C->user_begin();
 694     else
 695       ++I;
 696   }
 697
 698   if (RemoveDeadUsers) {
 699     // If C is only used by metadata, it should not be preserved but should
 700     // have its uses replaced.
 701     ReplaceableMetadataImpl::SalvageDebugInfo(*C);
 702     const_cast<Constant *>(C)->destroyConstant();
 703   }
 704
 705   return true;
 706 }
 707
 708 void Constant::removeDeadConstantUsers() const {
 709   Value::const_user_iterator I = user_begin(), E = user_end();
 710   Value::const_user_iterator LastNonDeadUser = E;
 711   while (I != E) {
 712     const Constant *User = dyn_cast<Constant>(*I);
 713     if (!User) {
 714       LastNonDeadUser = I;
 715       ++I;
 716       continue;
 717     }
 718
 719     if (!constantIsDead(User, /* RemoveDeadUsers= */ true)) {
 720       // If the constant wasn't dead, remember that this was the last live use
 721       // and move on to the next constant.
 722       LastNonDeadUser = I;
 723       ++I;
 724       continue;
 725     }
 726
 727     // If the constant was dead, then the iterator is invalidated.
 728     if (LastNonDeadUser == E)
 729       I = user_begin();
 730     else
 731       I = std::next(LastNonDeadUser);
 732   }
 733 }
 734
 735 bool Constant::hasOneLiveUse() const { return hasNLiveUses(1); }
 736
 737 bool Constant::hasZeroLiveUses() const { return hasNLiveUses(0); }
 738
 739 bool Constant::hasNLiveUses(unsigned N) const {
 740   unsigned NumUses = 0;
 741   for (const Use &U : uses()) {
 742     const Constant *User = dyn_cast<Constant>(U.getUser());
 743     if (!User || !constantIsDead(User, /* RemoveDeadUsers= */ false)) {
 744       ++NumUses;
 745
 746       if (NumUses > N)
 747         return false;
 748     }
 749   }
 750   return NumUses == N;
 751 }
 752
 753 Constant *Constant::replaceUndefsWith(Constant *C, Constant *Replacement) {
 754   assert(C && Replacement && "Expected non-nullptr constant arguments");
 755   Type *Ty = C->getType();
 756   if (match(C, m_Undef())) {
 757     assert(Ty == Replacement->getType() && "Expected matching types");
 758     return Replacement;
 759   }
 760
 761   // Don't know how to deal with this constant.
 762   auto *VTy = dyn_cast<FixedVectorType>(Ty);
 763   if (!VTy)
 764     return C;
 765
 766   unsigned NumElts = VTy->getNumElements();
 767   SmallVector<Constant *, 32> NewC(NumElts);
 768   for (unsigned i = 0; i != NumElts; ++i) {
 769     Constant *EltC = C->getAggregateElement(i);
 770     assert((!EltC || EltC->getType() == Replacement->getType()) &&
 771            "Expected matching types");
 772     NewC[i] = EltC && match(EltC, m_Undef()) ? Replacement : EltC;
 773   }
 774   return ConstantVector::get(NewC);
 775 }
 776
 777 Constant *Constant::mergeUndefsWith(Constant *C, Constant *Other) {
 778   assert(C && Other && "Expected non-nullptr constant arguments");
 779   if (match(C, m_Undef()))
 780     return C;
 781
 782   Type *Ty = C->getType();
 783   if (match(Other, m_Undef()))
 784     return UndefValue::get(Ty);
 785
 786   auto *VTy = dyn_cast<FixedVectorType>(Ty);
 787   if (!VTy)
 788     return C;
 789
 790   Type *EltTy = VTy->getElementType();
 791   unsigned NumElts = VTy->getNumElements();
 792   assert(isa<FixedVectorType>(Other->getType()) &&
 793          cast<FixedVectorType>(Other->getType())->getNumElements() == NumElts &&
 794          "Type mismatch");
 795
 796   bool FoundExtraUndef = false;
 797   SmallVector<Constant *, 32> NewC(NumElts);
 798   for (unsigned I = 0; I != NumElts; ++I) {
 799     NewC[I] = C->getAggregateElement(I);
 800     Constant *OtherEltC = Other->getAggregateElement(I);
 801     assert(NewC[I] && OtherEltC && "Unknown vector element");
 802     if (!match(NewC[I], m_Undef()) && match(OtherEltC, m_Undef())) {
 803       NewC[I] = UndefValue::get(EltTy);
 804       FoundExtraUndef = true;
 805     }
 806   }
 807   if (FoundExtraUndef)
 808     return ConstantVector::get(NewC);
 809   return C;
 810 }
 811
 812 bool Constant::isManifestConstant() const {
 813   if (isa<ConstantData>(this))
 814     return true;
 815   if (isa<ConstantAggregate>(this) || isa<ConstantExpr>(this)) {
 816     for (const Value *Op : operand_values())
 817       if (!cast<Constant>(Op)->isManifestConstant())
 818         return false;
 819     return true;
 820   }
 821   return false;
 822 }
 823
 824 //===----------------------------------------------------------------------===//
 825 //                                ConstantInt
 826 //===----------------------------------------------------------------------===//
 827
 828 ConstantInt::ConstantInt(IntegerType *Ty, const APInt &V)
 829     : ConstantData(Ty, ConstantIntVal), Val(V) {
 830   assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type");
 831 }
 832
 833 ConstantInt *ConstantInt::getTrue(LLVMContext &Context) {
 834   LLVMContextImpl *pImpl = Context.pImpl;
 835   if (!pImpl->TheTrueVal)
 836     pImpl->TheTrueVal = ConstantInt::get(Type::getInt1Ty(Context), 1);
 837   return pImpl->TheTrueVal;
 838 }
 839
 840 ConstantInt *ConstantInt::getFalse(LLVMContext &Context) {
 841   LLVMContextImpl *pImpl = Context.pImpl;
 842   if (!pImpl->TheFalseVal)
 843     pImpl->TheFalseVal = ConstantInt::get(Type::getInt1Ty(Context), 0);
 844   return pImpl->TheFalseVal;
 845 }
 846
 847 ConstantInt *ConstantInt::getBool(LLVMContext &Context, bool V) {
 848   return V ? getTrue(Context) : getFalse(Context);
 849 }
 850
 851 Constant *ConstantInt::getTrue(Type *Ty) {
 852   assert(Ty->isIntOrIntVectorTy(1) && "Type not i1 or vector of i1.");
 853   ConstantInt *TrueC = ConstantInt::getTrue(Ty->getContext());
 854   if (auto *VTy = dyn_cast<VectorType>(Ty))
 855     return ConstantVector::getSplat(VTy->getElementCount(), TrueC);
 856   return TrueC;
 857 }
 858
 859 Constant *ConstantInt::getFalse(Type *Ty) {
 860   assert(Ty->isIntOrIntVectorTy(1) && "Type not i1 or vector of i1.");
 861   ConstantInt *FalseC = ConstantInt::getFalse(Ty->getContext());
 862   if (auto *VTy = dyn_cast<VectorType>(Ty))
 863     return ConstantVector::getSplat(VTy->getElementCount(), FalseC);
 864   return FalseC;
 865 }
 866
 867 Constant *ConstantInt::getBool(Type *Ty, bool V) {
 868   return V ? getTrue(Ty) : getFalse(Ty);
 869 }
 870
 871 // Get a ConstantInt from an APInt.
 872 ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) {
 873   // get an existing value or the insertion position
 874   LLVMContextImpl *pImpl = Context.pImpl;
 875   std::unique_ptr<ConstantInt> &Slot =
 876       V.isZero()  ? pImpl->IntZeroConstants[V.getBitWidth()]
 877       : V.isOne() ? pImpl->IntOneConstants[V.getBitWidth()]
 878                   : pImpl->IntConstants[V];
 879   if (!Slot) {
 880     // Get the corresponding integer type for the bit width of the value.
 881     IntegerType *ITy = IntegerType::get(Context, V.getBitWidth());
 882     Slot.reset(new ConstantInt(ITy, V));
 883   }
 884   assert(Slot->getType() == IntegerType::get(Context, V.getBitWidth()));
 885   return Slot.get();
 886 }
 887
 888 Constant *ConstantInt::get(Type *Ty, uint64_t V, bool isSigned) {
 889   Constant *C = get(cast<IntegerType>(Ty->getScalarType()), V, isSigned);
 890
 891   // For vectors, broadcast the value.
 892   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 893     return ConstantVector::getSplat(VTy->getElementCount(), C);
 894
 895   return C;
 896 }
 897
 898 ConstantInt *ConstantInt::get(IntegerType *Ty, uint64_t V, bool isSigned) {
 899   return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
 900 }
 901
 902 Constant *ConstantInt::get(Type *Ty, const APInt& V) {
 903   ConstantInt *C = get(Ty->getContext(), V);
 904   assert(C->getType() == Ty->getScalarType() &&
 905          "ConstantInt type doesn't match the type implied by its value!");
 906
 907   // For vectors, broadcast the value.
 908   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 909     return ConstantVector::getSplat(VTy->getElementCount(), C);
 910
 911   return C;
 912 }
 913
 914 ConstantInt *ConstantInt::get(IntegerType* Ty, StringRef Str, uint8_t radix) {
 915   return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix));
 916 }
 917
 918 /// Remove the constant from the constant table.
 919 void ConstantInt::destroyConstantImpl() {
 920   llvm_unreachable("You can't ConstantInt->destroyConstantImpl()!");
 921 }
 922
 923 //===----------------------------------------------------------------------===//
 924 //                                ConstantFP
 925 //===----------------------------------------------------------------------===//
 926
 927 Constant *ConstantFP::get(Type *Ty, double V) {
 928   LLVMContext &Context = Ty->getContext();
 929
 930   APFloat FV(V);
 931   bool ignored;
 932   FV.convert(Ty->getScalarType()->getFltSemantics(),
 933              APFloat::rmNearestTiesToEven, &ignored);
 934   Constant *C = get(Context, FV);
 935
 936   // For vectors, broadcast the value.
 937   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 938     return ConstantVector::getSplat(VTy->getElementCount(), C);
 939
 940   return C;
 941 }
 942
 943 Constant *ConstantFP::get(Type *Ty, const APFloat &V) {
 944   ConstantFP *C = get(Ty->getContext(), V);
 945   assert(C->getType() == Ty->getScalarType() &&
 946          "ConstantFP type doesn't match the type implied by its value!");
 947
 948   // For vectors, broadcast the value.
 949   if (auto *VTy = dyn_cast<VectorType>(Ty))
 950     return ConstantVector::getSplat(VTy->getElementCount(), C);
 951
 952   return C;
 953 }
 954
 955 Constant *ConstantFP::get(Type *Ty, StringRef Str) {
 956   LLVMContext &Context = Ty->getContext();
 957
 958   APFloat FV(Ty->getScalarType()->getFltSemantics(), Str);
 959   Constant *C = get(Context, FV);
 960
 961   // For vectors, broadcast the value.
 962   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 963     return ConstantVector::getSplat(VTy->getElementCount(), C);
 964
 965   return C;
 966 }
 967
 968 Constant *ConstantFP::getNaN(Type *Ty, bool Negative, uint64_t Payload) {
 969   const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
 970   APFloat NaN = APFloat::getNaN(Semantics, Negative, Payload);
 971   Constant *C = get(Ty->getContext(), NaN);
 972
 973   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 974     return ConstantVector::getSplat(VTy->getElementCount(), C);
 975
 976   return C;
 977 }
 978
 979 Constant *ConstantFP::getQNaN(Type *Ty, bool Negative, APInt *Payload) {
 980   const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
 981   APFloat NaN = APFloat::getQNaN(Semantics, Negative, Payload);
 982   Constant *C = get(Ty->getContext(), NaN);
 983
 984   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 985     return ConstantVector::getSplat(VTy->getElementCount(), C);
 986
 987   return C;
 988 }
 989
 990 Constant *ConstantFP::getSNaN(Type *Ty, bool Negative, APInt *Payload) {
 991   const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
 992   APFloat NaN = APFloat::getSNaN(Semantics, Negative, Payload);
 993   Constant *C = get(Ty->getContext(), NaN);
 994
 995   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
 996     return ConstantVector::getSplat(VTy->getElementCount(), C);
 997
 998   return C;
 999 }
1000
1001 Constant *ConstantFP::getZero(Type *Ty, bool Negative) {
1002   const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
1003   APFloat NegZero = APFloat::getZero(Semantics, Negative);
1004   Constant *C = get(Ty->getContext(), NegZero);
1005
1006   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
1007     return ConstantVector::getSplat(VTy->getElementCount(), C);
1008
1009   return C;
1010 }
1011
1012
1013 // ConstantFP accessors.
1014 ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
1015   LLVMContextImpl* pImpl = Context.pImpl;
1016
1017   std::unique_ptr<ConstantFP> &Slot = pImpl->FPConstants[V];
1018
1019   if (!Slot) {
1020     Type *Ty = Type::getFloatingPointTy(Context, V.getSemantics());
1021     Slot.reset(new ConstantFP(Ty, V));
1022   }
1023
1024   return Slot.get();
1025 }
1026
1027 Constant *ConstantFP::getInfinity(Type *Ty, bool Negative) {
1028   const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
1029   Constant *C = get(Ty->getContext(), APFloat::getInf(Semantics, Negative));
1030
1031   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
1032     return ConstantVector::getSplat(VTy->getElementCount(), C);
1033
1034   return C;
1035 }
1036
1037 ConstantFP::ConstantFP(Type *Ty, const APFloat &V)
1038     : ConstantData(Ty, ConstantFPVal), Val(V) {
1039   assert(&V.getSemantics() == &Ty->getFltSemantics() &&
1040          "FP type Mismatch");
1041 }
1042
1043 bool ConstantFP::isExactlyValue(const APFloat &V) const {
1044   return Val.bitwiseIsEqual(V);
1045 }
1046
1047 /// Remove the constant from the constant table.
1048 void ConstantFP::destroyConstantImpl() {
1049   llvm_unreachable("You can't ConstantFP->destroyConstantImpl()!");
1050 }
1051
1052 //===----------------------------------------------------------------------===//
1053 //                   ConstantAggregateZero Implementation
1054 //===----------------------------------------------------------------------===//
1055
1056 Constant *ConstantAggregateZero::getSequentialElement() const {
1057   if (auto *AT = dyn_cast<ArrayType>(getType()))
1058     return Constant::getNullValue(AT->getElementType());
1059   return Constant::getNullValue(cast<VectorType>(getType())->getElementType());
1060 }
1061
1062 Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const {
1063   return Constant::getNullValue(getType()->getStructElementType(Elt));
1064 }
1065
1066 Constant *ConstantAggregateZero::getElementValue(Constant *C) const {
1067   if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
1068     return getSequentialElement();
1069   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
1070 }
1071
1072 Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const {
1073   if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
1074     return getSequentialElement();
1075   return getStructElement(Idx);
1076 }
1077
1078 ElementCount ConstantAggregateZero::getElementCount() const {
1079   Type *Ty = getType();
1080   if (auto *AT = dyn_cast<ArrayType>(Ty))
1081     return ElementCount::getFixed(AT->getNumElements());
1082   if (auto *VT = dyn_cast<VectorType>(Ty))
1083     return VT->getElementCount();
1084   return ElementCount::getFixed(Ty->getStructNumElements());
1085 }
1086
1087 //===----------------------------------------------------------------------===//
1088 //                         UndefValue Implementation
1089 //===----------------------------------------------------------------------===//
1090
1091 UndefValue *UndefValue::getSequentialElement() const {
1092   if (ArrayType *ATy = dyn_cast<ArrayType>(getType()))
1093     return UndefValue::get(ATy->getElementType());
1094   return UndefValue::get(cast<VectorType>(getType())->getElementType());
1095 }
1096
1097 UndefValue *UndefValue::getStructElement(unsigned Elt) const {
1098   return UndefValue::get(getType()->getStructElementType(Elt));
1099 }
1100
1101 UndefValue *UndefValue::getElementValue(Constant *C) const {
1102   if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
1103     return getSequentialElement();
1104   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
1105 }
1106
1107 UndefValue *UndefValue::getElementValue(unsigned Idx) const {
1108   if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
1109     return getSequentialElement();
1110   return getStructElement(Idx);
1111 }
1112
1113 unsigned UndefValue::getNumElements() const {
1114   Type *Ty = getType();
1115   if (auto *AT = dyn_cast<ArrayType>(Ty))
1116     return AT->getNumElements();
1117   if (auto *VT = dyn_cast<VectorType>(Ty))
1118     return cast<FixedVectorType>(VT)->getNumElements();
1119   return Ty->getStructNumElements();
1120 }
1121
1122 //===----------------------------------------------------------------------===//
1123 //                         PoisonValue Implementation
1124 //===----------------------------------------------------------------------===//
1125
1126 PoisonValue *PoisonValue::getSequentialElement() const {
1127   if (ArrayType *ATy = dyn_cast<ArrayType>(getType()))
1128     return PoisonValue::get(ATy->getElementType());
1129   return PoisonValue::get(cast<VectorType>(getType())->getElementType());
1130 }
1131
1132 PoisonValue *PoisonValue::getStructElement(unsigned Elt) const {
1133   return PoisonValue::get(getType()->getStructElementType(Elt));
1134 }
1135
1136 PoisonValue *PoisonValue::getElementValue(Constant *C) const {
1137   if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
1138     return getSequentialElement();
1139   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
1140 }
1141
1142 PoisonValue *PoisonValue::getElementValue(unsigned Idx) const {
1143   if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
1144     return getSequentialElement();
1145   return getStructElement(Idx);
1146 }
1147
1148 //===----------------------------------------------------------------------===//
1149 //                            ConstantXXX Classes
1150 //===----------------------------------------------------------------------===//
1151
1152 template <typename ItTy, typename EltTy>
1153 static bool rangeOnlyContains(ItTy Start, ItTy End, EltTy Elt) {
1154   for (; Start != End; ++Start)
1155     if (*Start != Elt)
1156       return false;
1157   return true;
1158 }
1159
1160 template <typename SequentialTy, typename ElementTy>
1161 static Constant *getIntSequenceIfElementsMatch(ArrayRef<Constant *> V) {
1162   assert(!V.empty() && "Cannot get empty int sequence.");
1163
1164   SmallVector<ElementTy, 16> Elts;
1165   for (Constant *C : V)
1166     if (auto *CI = dyn_cast<ConstantInt>(C))
1167       Elts.push_back(CI->getZExtValue());
1168     else
1169       return nullptr;
1170   return SequentialTy::get(V[0]->getContext(), Elts);
1171 }
1172
1173 template <typename SequentialTy, typename ElementTy>
1174 static Constant *getFPSequenceIfElementsMatch(ArrayRef<Constant *> V) {
1175   assert(!V.empty() && "Cannot get empty FP sequence.");
1176
1177   SmallVector<ElementTy, 16> Elts;
1178   for (Constant *C : V)
1179     if (auto *CFP = dyn_cast<ConstantFP>(C))
1180       Elts.push_back(CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
1181     else
1182       return nullptr;
1183   return SequentialTy::getFP(V[0]->getType(), Elts);
1184 }
1185
1186 template <typename SequenceTy>
1187 static Constant *getSequenceIfElementsMatch(Constant *C,
1188                                             ArrayRef<Constant *> V) {
1189   // We speculatively build the elements here even if it turns out that there is
1190   // a constantexpr or something else weird, since it is so uncommon for that to
1191   // happen.
1192   if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
1193     if (CI->getType()->isIntegerTy(8))
1194       return getIntSequenceIfElementsMatch<SequenceTy, uint8_t>(V);
1195     else if (CI->getType()->isIntegerTy(16))
1196       return getIntSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
1197     else if (CI->getType()->isIntegerTy(32))
1198       return getIntSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
1199     else if (CI->getType()->isIntegerTy(64))
1200       return getIntSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
1201   } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1202     if (CFP->getType()->isHalfTy() || CFP->getType()->isBFloatTy())
1203       return getFPSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
1204     else if (CFP->getType()->isFloatTy())
1205       return getFPSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
1206     else if (CFP->getType()->isDoubleTy())
1207       return getFPSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
1208   }
1209
1210   return nullptr;
1211 }
1212
1213 ConstantAggregate::ConstantAggregate(Type *T, ValueTy VT,
1214                                      ArrayRef<Constant *> V)
1215     : Constant(T, VT, OperandTraits<ConstantAggregate>::op_end(this) - V.size(),
1216                V.size()) {
1217   llvm::copy(V, op_begin());
1218
1219   // Check that types match, unless this is an opaque struct.
1220   if (auto *ST = dyn_cast<StructType>(T)) {
1221     if (ST->isOpaque())
1222       return;
1223     for (unsigned I = 0, E = V.size(); I != E; ++I)
1224       assert(V[I]->getType() == ST->getTypeAtIndex(I) &&
1225              "Initializer for struct element doesn't match!");
1226   }
1227 }
1228
1229 ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V)
1230     : ConstantAggregate(T, ConstantArrayVal, V) {
1231   assert(V.size() == T->getNumElements() &&
1232          "Invalid initializer for constant array");
1233 }
1234
1235 Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) {
1236   if (Constant *C = getImpl(Ty, V))
1237     return C;
1238   return Ty->getContext().pImpl->ArrayConstants.getOrCreate(Ty, V);
1239 }
1240
1241 Constant *ConstantArray::getImpl(ArrayType *Ty, ArrayRef<Constant*> V) {
1242   // Empty arrays are canonicalized to ConstantAggregateZero.
1243   if (V.empty())
1244     return ConstantAggregateZero::get(Ty);
1245
1246   for (Constant *C : V) {
1247     assert(C->getType() == Ty->getElementType() &&
1248            "Wrong type in array element initializer");
1249     (void)C;
1250   }
1251
1252   // If this is an all-zero array, return a ConstantAggregateZero object.  If
1253   // all undef, return an UndefValue, if "all simple", then return a
1254   // ConstantDataArray.
1255   Constant *C = V[0];
1256   if (isa<PoisonValue>(C) && rangeOnlyContains(V.begin(), V.end(), C))
1257     return PoisonValue::get(Ty);
1258
1259   if (isa<UndefValue>(C) && rangeOnlyContains(V.begin(), V.end(), C))
1260     return UndefValue::get(Ty);
1261
1262   if (C->isNullValue() && rangeOnlyContains(V.begin(), V.end(), C))
1263     return ConstantAggregateZero::get(Ty);
1264
1265   // Check to see if all of the elements are ConstantFP or ConstantInt and if
1266   // the element type is compatible with ConstantDataVector.  If so, use it.
1267   if (ConstantDataSequential::isElementTypeCompatible(C->getType()))
1268     return getSequenceIfElementsMatch<ConstantDataArray>(C, V);
1269
1270   // Otherwise, we really do want to create a ConstantArray.
1271   return nullptr;
1272 }
1273
1274 StructType *ConstantStruct::getTypeForElements(LLVMContext &Context,
1275                                                ArrayRef<Constant*> V,
1276                                                bool Packed) {
1277   unsigned VecSize = V.size();
1278   SmallVector<Type*, 16> EltTypes(VecSize);
1279   for (unsigned i = 0; i != VecSize; ++i)
1280     EltTypes[i] = V[i]->getType();
1281
1282   return StructType::get(Context, EltTypes, Packed);
1283 }
1284
1285
1286 StructType *ConstantStruct::getTypeForElements(ArrayRef<Constant*> V,
1287                                                bool Packed) {
1288   assert(!V.empty() &&
1289          "ConstantStruct::getTypeForElements cannot be called on empty list");
1290   return getTypeForElements(V[0]->getContext(), V, Packed);
1291 }
1292
1293 ConstantStruct::ConstantStruct(StructType *T, ArrayRef<Constant *> V)
1294     : ConstantAggregate(T, ConstantStructVal, V) {
1295   assert((T->isOpaque() || V.size() == T->getNumElements()) &&
1296          "Invalid initializer for constant struct");
1297 }
1298
1299 // ConstantStruct accessors.
1300 Constant *ConstantStruct::get(StructType *ST, ArrayRef<Constant*> V) {
1301   assert((ST->isOpaque() || ST->getNumElements() == V.size()) &&
1302          "Incorrect # elements specified to ConstantStruct::get");
1303
1304   // Create a ConstantAggregateZero value if all elements are zeros.
1305   bool isZero = true;
1306   bool isUndef = false;
1307   bool isPoison = false;
1308
1309   if (!V.empty()) {
1310     isUndef = isa<UndefValue>(V[0]);
1311     isPoison = isa<PoisonValue>(V[0]);
1312     isZero = V[0]->isNullValue();
1313     // PoisonValue inherits UndefValue, so its check is not necessary.
1314     if (isUndef || isZero) {
1315       for (Constant *C : V) {
1316         if (!C->isNullValue())
1317           isZero = false;
1318         if (!isa<PoisonValue>(C))
1319           isPoison = false;
1320         if (isa<PoisonValue>(C) || !isa<UndefValue>(C))
1321           isUndef = false;
1322       }
1323     }
1324   }
1325   if (isZero)
1326     return ConstantAggregateZero::get(ST);
1327   if (isPoison)
1328     return PoisonValue::get(ST);
1329   if (isUndef)
1330     return UndefValue::get(ST);
1331
1332   return ST->getContext().pImpl->StructConstants.getOrCreate(ST, V);
1333 }
1334
1335 ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V)
1336     : ConstantAggregate(T, ConstantVectorVal, V) {
1337   assert(V.size() == cast<FixedVectorType>(T)->getNumElements() &&
1338          "Invalid initializer for constant vector");
1339 }
1340
1341 // ConstantVector accessors.
1342 Constant *ConstantVector::get(ArrayRef<Constant*> V) {
1343   if (Constant *C = getImpl(V))
1344     return C;
1345   auto *Ty = FixedVectorType::get(V.front()->getType(), V.size());
1346   return Ty->getContext().pImpl->VectorConstants.getOrCreate(Ty, V);
1347 }
1348
1349 Constant *ConstantVector::getImpl(ArrayRef<Constant*> V) {
1350   assert(!V.empty() && "Vectors can't be empty");
1351   auto *T = FixedVectorType::get(V.front()->getType(), V.size());
1352
1353   // If this is an all-undef or all-zero vector, return a
1354   // ConstantAggregateZero or UndefValue.
1355   Constant *C = V[0];
1356   bool isZero = C->isNullValue();
1357   bool isUndef = isa<UndefValue>(C);
1358   bool isPoison = isa<PoisonValue>(C);
1359
1360   if (isZero || isUndef) {
1361     for (unsigned i = 1, e = V.size(); i != e; ++i)
1362       if (V[i] != C) {
1363         isZero = isUndef = isPoison = false;
1364         break;
1365       }
1366   }
1367
1368   if (isZero)
1369     return ConstantAggregateZero::get(T);
1370   if (isPoison)
1371     return PoisonValue::get(T);
1372   if (isUndef)
1373     return UndefValue::get(T);
1374
1375   // Check to see if all of the elements are ConstantFP or ConstantInt and if
1376   // the element type is compatible with ConstantDataVector.  If so, use it.
1377   if (ConstantDataSequential::isElementTypeCompatible(C->getType()))
1378     return getSequenceIfElementsMatch<ConstantDataVector>(C, V);
1379
1380   // Otherwise, the element type isn't compatible with ConstantDataVector, or
1381   // the operand list contains a ConstantExpr or something else strange.
1382   return nullptr;
1383 }
1384
1385 Constant *ConstantVector::getSplat(ElementCount EC, Constant *V) {
1386   if (!EC.isScalable()) {
1387     // If this splat is compatible with ConstantDataVector, use it instead of
1388     // ConstantVector.
1389     if ((isa<ConstantFP>(V) || isa<ConstantInt>(V)) &&
1390         ConstantDataSequential::isElementTypeCompatible(V->getType()))
1391       return ConstantDataVector::getSplat(EC.getKnownMinValue(), V);
1392
1393     SmallVector<Constant *, 32> Elts(EC.getKnownMinValue(), V);
1394     return get(Elts);
1395   }
1396
1397   Type *VTy = VectorType::get(V->getType(), EC);
1398
1399   if (V->isNullValue())
1400     return ConstantAggregateZero::get(VTy);
1401   else if (isa<UndefValue>(V))
1402     return UndefValue::get(VTy);
1403
1404   Type *IdxTy = Type::getInt64Ty(VTy->getContext());
1405
1406   // Move scalar into vector.
1407   Constant *PoisonV = PoisonValue::get(VTy);
1408   V = ConstantExpr::getInsertElement(PoisonV, V, ConstantInt::get(IdxTy, 0));
1409   // Build shuffle mask to perform the splat.
1410   SmallVector<int, 8> Zeros(EC.getKnownMinValue(), 0);
1411   // Splat.
1412   return ConstantExpr::getShuffleVector(V, PoisonV, Zeros);
1413 }
1414
1415 ConstantTokenNone *ConstantTokenNone::get(LLVMContext &Context) {
1416   LLVMContextImpl *pImpl = Context.pImpl;
1417   if (!pImpl->TheNoneToken)
1418     pImpl->TheNoneToken.reset(new ConstantTokenNone(Context));
1419   return pImpl->TheNoneToken.get();
1420 }
1421
1422 /// Remove the constant from the constant table.
1423 void ConstantTokenNone::destroyConstantImpl() {
1424   llvm_unreachable("You can't ConstantTokenNone->destroyConstantImpl()!");
1425 }
1426
1427 // Utility function for determining if a ConstantExpr is a CastOp or not. This
1428 // can't be inline because we don't want to #include Instruction.h into
1429 // Constant.h
1430 bool ConstantExpr::isCast() const {
1431   return Instruction::isCast(getOpcode());
1432 }
1433
1434 bool ConstantExpr::isCompare() const {
1435   return getOpcode() == Instruction::ICmp || getOpcode() == Instruction::FCmp;
1436 }
1437
1438 unsigned ConstantExpr::getPredicate() const {
1439   return cast<CompareConstantExpr>(this)->predicate;
1440 }
1441
1442 ArrayRef<int> ConstantExpr::getShuffleMask() const {
1443   return cast<ShuffleVectorConstantExpr>(this)->ShuffleMask;
1444 }
1445
1446 Constant *ConstantExpr::getShuffleMaskForBitcode() const {
1447   return cast<ShuffleVectorConstantExpr>(this)->ShuffleMaskForBitcode;
1448 }
1449
1450 Constant *ConstantExpr::getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1451                                         bool OnlyIfReduced, Type *SrcTy) const {
1452   assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
1453
1454   // If no operands changed return self.
1455   if (Ty == getType() && std::equal(Ops.begin(), Ops.end(), op_begin()))
1456     return const_cast<ConstantExpr*>(this);
1457
1458   Type *OnlyIfReducedTy = OnlyIfReduced ? Ty : nullptr;
1459   switch (getOpcode()) {
1460   case Instruction::Trunc:
1461   case Instruction::ZExt:
1462   case Instruction::SExt:
1463   case Instruction::FPTrunc:
1464   case Instruction::FPExt:
1465   case Instruction::UIToFP:
1466   case Instruction::SIToFP:
1467   case Instruction::FPToUI:
1468   case Instruction::FPToSI:
1469   case Instruction::PtrToInt:
1470   case Instruction::IntToPtr:
1471   case Instruction::BitCast:
1472   case Instruction::AddrSpaceCast:
1473     return ConstantExpr::getCast(getOpcode(), Ops[0], Ty, OnlyIfReduced);
1474   case Instruction::InsertElement:
1475     return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2],
1476                                           OnlyIfReducedTy);
1477   case Instruction::ExtractElement:
1478     return ConstantExpr::getExtractElement(Ops[0], Ops[1], OnlyIfReducedTy);
1479   case Instruction::ShuffleVector:
1480     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], getShuffleMask(),
1481                                           OnlyIfReducedTy);
1482   case Instruction::GetElementPtr: {
1483     auto *GEPO = cast<GEPOperator>(this);
1484     assert(SrcTy || (Ops[0]->getType() == getOperand(0)->getType()));
1485     return ConstantExpr::getGetElementPtr(
1486         SrcTy ? SrcTy : GEPO->getSourceElementType(), Ops[0], Ops.slice(1),
1487         GEPO->isInBounds(), GEPO->getInRangeIndex(), OnlyIfReducedTy);
1488   }
1489   case Instruction::ICmp:
1490   case Instruction::FCmp:
1491     return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1],
1492                                     OnlyIfReducedTy);
1493   default:
1494     assert(getNumOperands() == 2 && "Must be binary operator?");
1495     return ConstantExpr::get(getOpcode(), Ops[0], Ops[1], SubclassOptionalData,
1496                              OnlyIfReducedTy);
1497   }
1498 }
1499
1500
1501 //===----------------------------------------------------------------------===//
1502 //                      isValueValidForType implementations
1503
1504 bool ConstantInt::isValueValidForType(Type *Ty, uint64_t Val) {
1505   unsigned NumBits = Ty->getIntegerBitWidth(); // assert okay
1506   if (Ty->isIntegerTy(1))
1507     return Val == 0 || Val == 1;
1508   return isUIntN(NumBits, Val);
1509 }
1510
1511 bool ConstantInt::isValueValidForType(Type *Ty, int64_t Val) {
1512   unsigned NumBits = Ty->getIntegerBitWidth();
1513   if (Ty->isIntegerTy(1))
1514     return Val == 0 || Val == 1 || Val == -1;
1515   return isIntN(NumBits, Val);
1516 }
1517
1518 bool ConstantFP::isValueValidForType(Type *Ty, const APFloat& Val) {
1519   // convert modifies in place, so make a copy.
1520   APFloat Val2 = APFloat(Val);
1521   bool losesInfo;
1522   switch (Ty->getTypeID()) {
1523   default:
1524     return false;         // These can't be represented as floating point!
1525
1526   // FIXME rounding mode needs to be more flexible
1527   case Type::HalfTyID: {
1528     if (&Val2.getSemantics() == &APFloat::IEEEhalf())
1529       return true;
1530     Val2.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &losesInfo);
1531     return !losesInfo;
1532   }
1533   case Type::BFloatTyID: {
1534     if (&Val2.getSemantics() == &APFloat::BFloat())
1535       return true;
1536     Val2.convert(APFloat::BFloat(), APFloat::rmNearestTiesToEven, &losesInfo);
1537     return !losesInfo;
1538   }
1539   case Type::FloatTyID: {
1540     if (&Val2.getSemantics() == &APFloat::IEEEsingle())
1541       return true;
1542     Val2.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven, &losesInfo);
1543     return !losesInfo;
1544   }
1545   case Type::DoubleTyID: {
1546     if (&Val2.getSemantics() == &APFloat::IEEEhalf() ||
1547         &Val2.getSemantics() == &APFloat::BFloat() ||
1548         &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1549         &Val2.getSemantics() == &APFloat::IEEEdouble())
1550       return true;
1551     Val2.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &losesInfo);
1552     return !losesInfo;
1553   }
1554   case Type::X86_FP80TyID:
1555     return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
1556            &Val2.getSemantics() == &APFloat::BFloat() ||
1557            &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1558            &Val2.getSemantics() == &APFloat::IEEEdouble() ||
1559            &Val2.getSemantics() == &APFloat::x87DoubleExtended();
1560   case Type::FP128TyID:
1561     return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
1562            &Val2.getSemantics() == &APFloat::BFloat() ||
1563            &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1564            &Val2.getSemantics() == &APFloat::IEEEdouble() ||
1565            &Val2.getSemantics() == &APFloat::IEEEquad();
1566   case Type::PPC_FP128TyID:
1567     return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
1568            &Val2.getSemantics() == &APFloat::BFloat() ||
1569            &Val2.getSemantics() == &APFloat::IEEEsingle() ||
1570            &Val2.getSemantics() == &APFloat::IEEEdouble() ||
1571            &Val2.getSemantics() == &APFloat::PPCDoubleDouble();
1572   }
1573 }
1574
1575
1576 //===----------------------------------------------------------------------===//
1577 //                      Factory Function Implementation
1578
1579 ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
1580   assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
1581          "Cannot create an aggregate zero of non-aggregate type!");
1582
1583   std::unique_ptr<ConstantAggregateZero> &Entry =
1584       Ty->getContext().pImpl->CAZConstants[Ty];
1585   if (!Entry)
1586     Entry.reset(new ConstantAggregateZero(Ty));
1587
1588   return Entry.get();
1589 }
1590
1591 /// Remove the constant from the constant table.
1592 void ConstantAggregateZero::destroyConstantImpl() {
1593   getContext().pImpl->CAZConstants.erase(getType());
1594 }
1595
1596 /// Remove the constant from the constant table.
1597 void ConstantArray::destroyConstantImpl() {
1598   getType()->getContext().pImpl->ArrayConstants.remove(this);
1599 }
1600
1601
1602 //---- ConstantStruct::get() implementation...
1603 //
1604
1605 /// Remove the constant from the constant table.
1606 void ConstantStruct::destroyConstantImpl() {
1607   getType()->getContext().pImpl->StructConstants.remove(this);
1608 }
1609
1610 /// Remove the constant from the constant table.
1611 void ConstantVector::destroyConstantImpl() {
1612   getType()->getContext().pImpl->VectorConstants.remove(this);
1613 }
1614
1615 Constant *Constant::getSplatValue(bool AllowUndefs) const {
1616   assert(this->getType()->isVectorTy() && "Only valid for vectors!");
1617   if (isa<ConstantAggregateZero>(this))
1618     return getNullValue(cast<VectorType>(getType())->getElementType());
1619   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
1620     return CV->getSplatValue();
1621   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
1622     return CV->getSplatValue(AllowUndefs);
1623
1624   // Check if this is a constant expression splat of the form returned by
1625   // ConstantVector::getSplat()
1626   const auto *Shuf = dyn_cast<ConstantExpr>(this);
1627   if (Shuf && Shuf->getOpcode() == Instruction::ShuffleVector &&
1628       isa<UndefValue>(Shuf->getOperand(1))) {
1629
1630     const auto *IElt = dyn_cast<ConstantExpr>(Shuf->getOperand(0));
1631     if (IElt && IElt->getOpcode() == Instruction::InsertElement &&
1632         isa<UndefValue>(IElt->getOperand(0))) {
1633
1634       ArrayRef<int> Mask = Shuf->getShuffleMask();
1635       Constant *SplatVal = IElt->getOperand(1);
1636       ConstantInt *Index = dyn_cast<ConstantInt>(IElt->getOperand(2));
1637
1638       if (Index && Index->getValue() == 0 &&
1639           llvm::all_of(Mask, [](int I) { return I == 0; }))
1640         return SplatVal;
1641     }
1642   }
1643
1644   return nullptr;
1645 }
1646
1647 Constant *ConstantVector::getSplatValue(bool AllowUndefs) const {
1648   // Check out first element.
1649   Constant *Elt = getOperand(0);
1650   // Then make sure all remaining elements point to the same value.
1651   for (unsigned I = 1, E = getNumOperands(); I < E; ++I) {
1652     Constant *OpC = getOperand(I);
1653     if (OpC == Elt)
1654       continue;
1655
1656     // Strict mode: any mismatch is not a splat.
1657     if (!AllowUndefs)
1658       return nullptr;
1659
1660     // Allow undefs mode: ignore undefined elements.
1661     if (isa<UndefValue>(OpC))
1662       continue;
1663
1664     // If we do not have a defined element yet, use the current operand.
1665     if (isa<UndefValue>(Elt))
1666       Elt = OpC;
1667
1668     if (OpC != Elt)
1669       return nullptr;
1670   }
1671   return Elt;
1672 }
1673
1674 const APInt &Constant::getUniqueInteger() const {
1675   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
1676     return CI->getValue();
1677   // Scalable vectors can use a ConstantExpr to build a splat.
1678   if (isa<ConstantExpr>(this))
1679     return cast<ConstantInt>(this->getSplatValue())->getValue();
1680   // For non-ConstantExpr we use getAggregateElement as a fast path to avoid
1681   // calling getSplatValue in release builds.
1682   assert(this->getSplatValue() && "Doesn't contain a unique integer!");
1683   const Constant *C = this->getAggregateElement(0U);
1684   assert(C && isa<ConstantInt>(C) && "Not a vector of numbers!");
1685   return cast<ConstantInt>(C)->getValue();
1686 }
1687
1688 //---- ConstantPointerNull::get() implementation.
1689 //
1690
1691 ConstantPointerNull *ConstantPointerNull::get(PointerType *Ty) {
1692   std::unique_ptr<ConstantPointerNull> &Entry =
1693       Ty->getContext().pImpl->CPNConstants[Ty];
1694   if (!Entry)
1695     Entry.reset(new ConstantPointerNull(Ty));
1696
1697   return Entry.get();
1698 }
1699
1700 /// Remove the constant from the constant table.
1701 void ConstantPointerNull::destroyConstantImpl() {
1702   getContext().pImpl->CPNConstants.erase(getType());
1703 }
1704
1705 //---- ConstantTargetNone::get() implementation.
1706 //
1707
1708 ConstantTargetNone *ConstantTargetNone::get(TargetExtType *Ty) {
1709   assert(Ty->hasProperty(TargetExtType::HasZeroInit) &&
1710          "Target extension type not allowed to have a zeroinitializer");
1711   std::unique_ptr<ConstantTargetNone> &Entry =
1712       Ty->getContext().pImpl->CTNConstants[Ty];
1713   if (!Entry)
1714     Entry.reset(new ConstantTargetNone(Ty));
1715
1716   return Entry.get();
1717 }
1718
1719 /// Remove the constant from the constant table.
1720 void ConstantTargetNone::destroyConstantImpl() {
1721   getContext().pImpl->CTNConstants.erase(getType());
1722 }
1723
1724 UndefValue *UndefValue::get(Type *Ty) {
1725   std::unique_ptr<UndefValue> &Entry = Ty->getContext().pImpl->UVConstants[Ty];
1726   if (!Entry)
1727     Entry.reset(new UndefValue(Ty));
1728
1729   return Entry.get();
1730 }
1731
1732 /// Remove the constant from the constant table.
1733 void UndefValue::destroyConstantImpl() {
1734   // Free the constant and any dangling references to it.
1735   if (getValueID() == UndefValueVal) {
1736     getContext().pImpl->UVConstants.erase(getType());
1737   } else if (getValueID() == PoisonValueVal) {
1738     getContext().pImpl->PVConstants.erase(getType());
1739   }
1740   llvm_unreachable("Not a undef or a poison!");
1741 }
1742
1743 PoisonValue *PoisonValue::get(Type *Ty) {
1744   std::unique_ptr<PoisonValue> &Entry = Ty->getContext().pImpl->PVConstants[Ty];
1745   if (!Entry)
1746     Entry.reset(new PoisonValue(Ty));
1747
1748   return Entry.get();
1749 }
1750
1751 /// Remove the constant from the constant table.
1752 void PoisonValue::destroyConstantImpl() {
1753   // Free the constant and any dangling references to it.
1754   getContext().pImpl->PVConstants.erase(getType());
1755 }
1756
1757 BlockAddress *BlockAddress::get(BasicBlock *BB) {
1758   assert(BB->getParent() && "Block must have a parent");
1759   return get(BB->getParent(), BB);
1760 }
1761
1762 BlockAddress *BlockAddress::get(Function *F, BasicBlock *BB) {
1763   BlockAddress *&BA =
1764     F->getContext().pImpl->BlockAddresses[std::make_pair(F, BB)];
1765   if (!BA)
1766     BA = new BlockAddress(F, BB);
1767
1768   assert(BA->getFunction() == F && "Basic block moved between functions");
1769   return BA;
1770 }
1771
1772 BlockAddress::BlockAddress(Function *F, BasicBlock *BB)
1773     : Constant(PointerType::get(F->getContext(), F->getAddressSpace()),
1774                Value::BlockAddressVal, &Op<0>(), 2) {
1775   setOperand(0, F);
1776   setOperand(1, BB);
1777   BB->AdjustBlockAddressRefCount(1);
1778 }
1779
1780 BlockAddress *BlockAddress::lookup(const BasicBlock *BB) {
1781   if (!BB->hasAddressTaken())
1782     return nullptr;
1783
1784   const Function *F = BB->getParent();
1785   assert(F && "Block must have a parent");
1786   BlockAddress *BA =
1787       F->getContext().pImpl->BlockAddresses.lookup(std::make_pair(F, BB));
1788   assert(BA && "Refcount and block address map disagree!");
1789   return BA;
1790 }
1791
1792 /// Remove the constant from the constant table.
1793 void BlockAddress::destroyConstantImpl() {
1794   getFunction()->getType()->getContext().pImpl
1795     ->BlockAddresses.erase(std::make_pair(getFunction(), getBasicBlock()));
1796   getBasicBlock()->AdjustBlockAddressRefCount(-1);
1797 }
1798
1799 Value *BlockAddress::handleOperandChangeImpl(Value *From, Value *To) {
1800   // This could be replacing either the Basic Block or the Function.  In either
1801   // case, we have to remove the map entry.
1802   Function *NewF = getFunction();
1803   BasicBlock *NewBB = getBasicBlock();
1804
1805   if (From == NewF)
1806     NewF = cast<Function>(To->stripPointerCasts());
1807   else {
1808     assert(From == NewBB && "From does not match any operand");
1809     NewBB = cast<BasicBlock>(To);
1810   }
1811
1812   // See if the 'new' entry already exists, if not, just update this in place
1813   // and return early.
1814   BlockAddress *&NewBA =
1815     getContext().pImpl->BlockAddresses[std::make_pair(NewF, NewBB)];
1816   if (NewBA)
1817     return NewBA;
1818
1819   getBasicBlock()->AdjustBlockAddressRefCount(-1);
1820
1821   // Remove the old entry, this can't cause the map to rehash (just a
1822   // tombstone will get added).
1823   getContext().pImpl->BlockAddresses.erase(std::make_pair(getFunction(),
1824                                                           getBasicBlock()));
1825   NewBA = this;
1826   setOperand(0, NewF);
1827   setOperand(1, NewBB);
1828   getBasicBlock()->AdjustBlockAddressRefCount(1);
1829
1830   // If we just want to keep the existing value, then return null.
1831   // Callers know that this means we shouldn't delete this value.
1832   return nullptr;
1833 }
1834
1835 DSOLocalEquivalent *DSOLocalEquivalent::get(GlobalValue *GV) {
1836   DSOLocalEquivalent *&Equiv = GV->getContext().pImpl->DSOLocalEquivalents[GV];
1837   if (!Equiv)
1838     Equiv = new DSOLocalEquivalent(GV);
1839
1840   assert(Equiv->getGlobalValue() == GV &&
1841          "DSOLocalFunction does not match the expected global value");
1842   return Equiv;
1843 }
1844
1845 DSOLocalEquivalent::DSOLocalEquivalent(GlobalValue *GV)
1846     : Constant(GV->getType(), Value::DSOLocalEquivalentVal, &Op<0>(), 1) {
1847   setOperand(0, GV);
1848 }
1849
1850 /// Remove the constant from the constant table.
1851 void DSOLocalEquivalent::destroyConstantImpl() {
1852   const GlobalValue *GV = getGlobalValue();
1853   GV->getContext().pImpl->DSOLocalEquivalents.erase(GV);
1854 }
1855
1856 Value *DSOLocalEquivalent::handleOperandChangeImpl(Value *From, Value *To) {
1857   assert(From == getGlobalValue() && "Changing value does not match operand.");
1858   assert(isa<Constant>(To) && "Can only replace the operands with a constant");
1859
1860   // The replacement is with another global value.
1861   if (const auto *ToObj = dyn_cast<GlobalValue>(To)) {
1862     DSOLocalEquivalent *&NewEquiv =
1863         getContext().pImpl->DSOLocalEquivalents[ToObj];
1864     if (NewEquiv)
1865       return llvm::ConstantExpr::getBitCast(NewEquiv, getType());
1866   }
1867
1868   // If the argument is replaced with a null value, just replace this constant
1869   // with a null value.
1870   if (cast<Constant>(To)->isNullValue())
1871     return To;
1872
1873   // The replacement could be a bitcast or an alias to another function. We can
1874   // replace it with a bitcast to the dso_local_equivalent of that function.
1875   auto *Func = cast<Function>(To->stripPointerCastsAndAliases());
1876   DSOLocalEquivalent *&NewEquiv = getContext().pImpl->DSOLocalEquivalents[Func];
1877   if (NewEquiv)
1878     return llvm::ConstantExpr::getBitCast(NewEquiv, getType());
1879
1880   // Replace this with the new one.
1881   getContext().pImpl->DSOLocalEquivalents.erase(getGlobalValue());
1882   NewEquiv = this;
1883   setOperand(0, Func);
1884
1885   if (Func->getType() != getType()) {
1886     // It is ok to mutate the type here because this constant should always
1887     // reflect the type of the function it's holding.
1888     mutateType(Func->getType());
1889   }
1890   return nullptr;
1891 }
1892
1893 NoCFIValue *NoCFIValue::get(GlobalValue *GV) {
1894   NoCFIValue *&NC = GV->getContext().pImpl->NoCFIValues[GV];
1895   if (!NC)
1896     NC = new NoCFIValue(GV);
1897
1898   assert(NC->getGlobalValue() == GV &&
1899          "NoCFIValue does not match the expected global value");
1900   return NC;
1901 }
1902
1903 NoCFIValue::NoCFIValue(GlobalValue *GV)
1904     : Constant(GV->getType(), Value::NoCFIValueVal, &Op<0>(), 1) {
1905   setOperand(0, GV);
1906 }
1907
1908 /// Remove the constant from the constant table.
1909 void NoCFIValue::destroyConstantImpl() {
1910   const GlobalValue *GV = getGlobalValue();
1911   GV->getContext().pImpl->NoCFIValues.erase(GV);
1912 }
1913
1914 Value *NoCFIValue::handleOperandChangeImpl(Value *From, Value *To) {
1915   assert(From == getGlobalValue() && "Changing value does not match operand.");
1916
1917   GlobalValue *GV = dyn_cast<GlobalValue>(To->stripPointerCasts());
1918   assert(GV && "Can only replace the operands with a global value");
1919
1920   NoCFIValue *&NewNC = getContext().pImpl->NoCFIValues[GV];
1921   if (NewNC)
1922     return llvm::ConstantExpr::getBitCast(NewNC, getType());
1923
1924   getContext().pImpl->NoCFIValues.erase(getGlobalValue());
1925   NewNC = this;
1926   setOperand(0, GV);
1927
1928   if (GV->getType() != getType())
1929     mutateType(GV->getType());
1930
1931   return nullptr;
1932 }
1933
1934 //---- ConstantExpr::get() implementations.
1935 //
1936
1937 /// This is a utility function to handle folding of casts and lookup of the
1938 /// cast in the ExprConstants map. It is used by the various get* methods below.
1939 static Constant *getFoldedCast(Instruction::CastOps opc, Constant *C, Type *Ty,
1940                                bool OnlyIfReduced = false) {
1941   assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
1942   // Fold a few common cases
1943   if (Constant *FC = ConstantFoldCastInstruction(opc, C, Ty))
1944     return FC;
1945
1946   if (OnlyIfReduced)
1947     return nullptr;
1948
1949   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
1950
1951   // Look up the constant in the table first to ensure uniqueness.
1952   ConstantExprKeyType Key(opc, C);
1953
1954   return pImpl->ExprConstants.getOrCreate(Ty, Key);
1955 }
1956
1957 Constant *ConstantExpr::getCast(unsigned oc, Constant *C, Type *Ty,
1958                                 bool OnlyIfReduced) {
1959   Instruction::CastOps opc = Instruction::CastOps(oc);
1960   assert(Instruction::isCast(opc) && "opcode out of range");
1961   assert(isSupportedCastOp(opc) &&
1962          "Cast opcode not supported as constant expression");
1963   assert(C && Ty && "Null arguments to getCast");
1964   assert(CastInst::castIsValid(opc, C, Ty) && "Invalid constantexpr cast!");
1965
1966   switch (opc) {
1967   default:
1968     llvm_unreachable("Invalid cast opcode");
1969   case Instruction::Trunc:
1970     return getTrunc(C, Ty, OnlyIfReduced);
1971   case Instruction::PtrToInt:
1972     return getPtrToInt(C, Ty, OnlyIfReduced);
1973   case Instruction::IntToPtr:
1974     return getIntToPtr(C, Ty, OnlyIfReduced);
1975   case Instruction::BitCast:
1976     return getBitCast(C, Ty, OnlyIfReduced);
1977   case Instruction::AddrSpaceCast:
1978     return getAddrSpaceCast(C, Ty, OnlyIfReduced);
1979   }
1980 }
1981
1982 Constant *ConstantExpr::getTruncOrBitCast(Constant *C, Type *Ty) {
1983   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1984     return getBitCast(C, Ty);
1985   return getTrunc(C, Ty);
1986 }
1987
1988 Constant *ConstantExpr::getPointerCast(Constant *S, Type *Ty) {
1989   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
1990   assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
1991           "Invalid cast");
1992
1993   if (Ty->isIntOrIntVectorTy())
1994     return getPtrToInt(S, Ty);
1995
1996   unsigned SrcAS = S->getType()->getPointerAddressSpace();
1997   if (Ty->isPtrOrPtrVectorTy() && SrcAS != Ty->getPointerAddressSpace())
1998     return getAddrSpaceCast(S, Ty);
1999
2000   return getBitCast(S, Ty);
2001 }
2002
2003 Constant *ConstantExpr::getPointerBitCastOrAddrSpaceCast(Constant *S,
2004                                                          Type *Ty) {
2005   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
2006   assert(Ty->isPtrOrPtrVectorTy() && "Invalid cast");
2007
2008   if (S->getType()->getPointerAddressSpace() != Ty->getPointerAddressSpace())
2009     return getAddrSpaceCast(S, Ty);
2010
2011   return getBitCast(S, Ty);
2012 }
2013
2014 Constant *ConstantExpr::getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced) {
2015 #ifndef NDEBUG
2016   bool fromVec = isa<VectorType>(C->getType());
2017   bool toVec = isa<VectorType>(Ty);
2018 #endif
2019   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
2020   assert(C->getType()->isIntOrIntVectorTy() && "Trunc operand must be integer");
2021   assert(Ty->isIntOrIntVectorTy() && "Trunc produces only integral");
2022   assert(C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
2023          "SrcTy must be larger than DestTy for Trunc!");
2024
2025   return getFoldedCast(Instruction::Trunc, C, Ty, OnlyIfReduced);
2026 }
2027
2028 Constant *ConstantExpr::getPtrToInt(Constant *C, Type *DstTy,
2029                                     bool OnlyIfReduced) {
2030   assert(C->getType()->isPtrOrPtrVectorTy() &&
2031          "PtrToInt source must be pointer or pointer vector");
2032   assert(DstTy->isIntOrIntVectorTy() &&
2033          "PtrToInt destination must be integer or integer vector");
2034   assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
2035   if (isa<VectorType>(C->getType()))
2036     assert(cast<VectorType>(C->getType())->getElementCount() ==
2037                cast<VectorType>(DstTy)->getElementCount() &&
2038            "Invalid cast between a different number of vector elements");
2039   return getFoldedCast(Instruction::PtrToInt, C, DstTy, OnlyIfReduced);
2040 }
2041
2042 Constant *ConstantExpr::getIntToPtr(Constant *C, Type *DstTy,
2043                                     bool OnlyIfReduced) {
2044   assert(C->getType()->isIntOrIntVectorTy() &&
2045          "IntToPtr source must be integer or integer vector");
2046   assert(DstTy->isPtrOrPtrVectorTy() &&
2047          "IntToPtr destination must be a pointer or pointer vector");
2048   assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
2049   if (isa<VectorType>(C->getType()))
2050     assert(cast<VectorType>(C->getType())->getElementCount() ==
2051                cast<VectorType>(DstTy)->getElementCount() &&
2052            "Invalid cast between a different number of vector elements");
2053   return getFoldedCast(Instruction::IntToPtr, C, DstTy, OnlyIfReduced);
2054 }
2055
2056 Constant *ConstantExpr::getBitCast(Constant *C, Type *DstTy,
2057                                    bool OnlyIfReduced) {
2058   assert(CastInst::castIsValid(Instruction::BitCast, C, DstTy) &&
2059          "Invalid constantexpr bitcast!");
2060
2061   // It is common to ask for a bitcast of a value to its own type, handle this
2062   // speedily.
2063   if (C->getType() == DstTy) return C;
2064
2065   return getFoldedCast(Instruction::BitCast, C, DstTy, OnlyIfReduced);
2066 }
2067
2068 Constant *ConstantExpr::getAddrSpaceCast(Constant *C, Type *DstTy,
2069                                          bool OnlyIfReduced) {
2070   assert(CastInst::castIsValid(Instruction::AddrSpaceCast, C, DstTy) &&
2071          "Invalid constantexpr addrspacecast!");
2072   return getFoldedCast(Instruction::AddrSpaceCast, C, DstTy, OnlyIfReduced);
2073 }
2074
2075 Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
2076                             unsigned Flags, Type *OnlyIfReducedTy) {
2077   // Check the operands for consistency first.
2078   assert(Instruction::isBinaryOp(Opcode) &&
2079          "Invalid opcode in binary constant expression");
2080   assert(isSupportedBinOp(Opcode) &&
2081          "Binop not supported as constant expression");
2082   assert(C1->getType() == C2->getType() &&
2083          "Operand types in binary constant expression should match");
2084
2085 #ifndef NDEBUG
2086   switch (Opcode) {
2087   case Instruction::Add:
2088   case Instruction::Sub:
2089   case Instruction::Mul:
2090     assert(C1->getType()->isIntOrIntVectorTy() &&
2091            "Tried to create an integer operation on a non-integer type!");
2092     break;
2093   case Instruction::And:
2094   case Instruction::Or:
2095   case Instruction::Xor:
2096     assert(C1->getType()->isIntOrIntVectorTy() &&
2097            "Tried to create a logical operation on a non-integral type!");
2098     break;
2099   case Instruction::Shl:
2100   case Instruction::LShr:
2101   case Instruction::AShr:
2102     assert(C1->getType()->isIntOrIntVectorTy() &&
2103            "Tried to create a shift operation on a non-integer type!");
2104     break;
2105   default:
2106     break;
2107   }
2108 #endif
2109
2110   if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
2111     return FC;
2112
2113   if (OnlyIfReducedTy == C1->getType())
2114     return nullptr;
2115
2116   Constant *ArgVec[] = { C1, C2 };
2117   ConstantExprKeyType Key(Opcode, ArgVec, 0, Flags);
2118
2119   LLVMContextImpl *pImpl = C1->getContext().pImpl;
2120   return pImpl->ExprConstants.getOrCreate(C1->getType(), Key);
2121 }
2122
2123 bool ConstantExpr::isDesirableBinOp(unsigned Opcode) {
2124   switch (Opcode) {
2125   case Instruction::UDiv:
2126   case Instruction::SDiv:
2127   case Instruction::URem:
2128   case Instruction::SRem:
2129   case Instruction::FAdd:
2130   case Instruction::FSub:
2131   case Instruction::FMul:
2132   case Instruction::FDiv:
2133   case Instruction::FRem:
2134   case Instruction::And:
2135   case Instruction::Or:
2136   case Instruction::LShr:
2137   case Instruction::AShr:
2138     return false;
2139   case Instruction::Add:
2140   case Instruction::Sub:
2141   case Instruction::Mul:
2142   case Instruction::Shl:
2143   case Instruction::Xor:
2144     return true;
2145   default:
2146     llvm_unreachable("Argument must be binop opcode");
2147   }
2148 }
2149
2150 bool ConstantExpr::isSupportedBinOp(unsigned Opcode) {
2151   switch (Opcode) {
2152   case Instruction::UDiv:
2153   case Instruction::SDiv:
2154   case Instruction::URem:
2155   case Instruction::SRem:
2156   case Instruction::FAdd:
2157   case Instruction::FSub:
2158   case Instruction::FMul:
2159   case Instruction::FDiv:
2160   case Instruction::FRem:
2161   case Instruction::And:
2162   case Instruction::Or:
2163   case Instruction::LShr:
2164   case Instruction::AShr:
2165     return false;
2166   case Instruction::Add:
2167   case Instruction::Sub:
2168   case Instruction::Mul:
2169   case Instruction::Shl:
2170   case Instruction::Xor:
2171     return true;
2172   default:
2173     llvm_unreachable("Argument must be binop opcode");
2174   }
2175 }
2176
2177 bool ConstantExpr::isDesirableCastOp(unsigned Opcode) {
2178   switch (Opcode) {
2179   case Instruction::ZExt:
2180   case Instruction::SExt:
2181   case Instruction::FPTrunc:
2182   case Instruction::FPExt:
2183   case Instruction::UIToFP:
2184   case Instruction::SIToFP:
2185   case Instruction::FPToUI:
2186   case Instruction::FPToSI:
2187     return false;
2188   case Instruction::Trunc:
2189   case Instruction::PtrToInt:
2190   case Instruction::IntToPtr:
2191   case Instruction::BitCast:
2192   case Instruction::AddrSpaceCast:
2193     return true;
2194   default:
2195     llvm_unreachable("Argument must be cast opcode");
2196   }
2197 }
2198
2199 bool ConstantExpr::isSupportedCastOp(unsigned Opcode) {
2200   switch (Opcode) {
2201   case Instruction::ZExt:
2202   case Instruction::SExt:
2203   case Instruction::FPTrunc:
2204   case Instruction::FPExt:
2205   case Instruction::UIToFP:
2206   case Instruction::SIToFP:
2207   case Instruction::FPToUI:
2208   case Instruction::FPToSI:
2209     return false;
2210   case Instruction::Trunc:
2211   case Instruction::PtrToInt:
2212   case Instruction::IntToPtr:
2213   case Instruction::BitCast:
2214   case Instruction::AddrSpaceCast:
2215     return true;
2216   default:
2217     llvm_unreachable("Argument must be cast opcode");
2218   }
2219 }
2220
2221 Constant *ConstantExpr::getSizeOf(Type* Ty) {
2222   // sizeof is implemented as: (i64) gep (Ty*)null, 1
2223   // Note that a non-inbounds gep is used, as null isn't within any object.
2224   Constant *GEPIdx = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
2225   Constant *GEP = getGetElementPtr(
2226       Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
2227   return getPtrToInt(GEP,
2228                      Type::getInt64Ty(Ty->getContext()));
2229 }
2230
2231 Constant *ConstantExpr::getAlignOf(Type* Ty) {
2232   // alignof is implemented as: (i64) gep ({i1,Ty}*)null, 0, 1
2233   // Note that a non-inbounds gep is used, as null isn't within any object.
2234   Type *AligningTy = StructType::get(Type::getInt1Ty(Ty->getContext()), Ty);
2235   Constant *NullPtr = Constant::getNullValue(PointerType::getUnqual(AligningTy->getContext()));
2236   Constant *Zero = ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0);
2237   Constant *One = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
2238   Constant *Indices[2] = { Zero, One };
2239   Constant *GEP = getGetElementPtr(AligningTy, NullPtr, Indices);
2240   return getPtrToInt(GEP,
2241                      Type::getInt64Ty(Ty->getContext()));
2242 }
2243
2244 Constant *ConstantExpr::getCompare(unsigned short Predicate, Constant *C1,
2245                                    Constant *C2, bool OnlyIfReduced) {
2246   assert(C1->getType() == C2->getType() && "Op types should be identical!");
2247
2248   switch (Predicate) {
2249   default: llvm_unreachable("Invalid CmpInst predicate");
2250   case CmpInst::FCMP_FALSE: case CmpInst::FCMP_OEQ: case CmpInst::FCMP_OGT:
2251   case CmpInst::FCMP_OGE:   case CmpInst::FCMP_OLT: case CmpInst::FCMP_OLE:
2252   case CmpInst::FCMP_ONE:   case CmpInst::FCMP_ORD: case CmpInst::FCMP_UNO:
2253   case CmpInst::FCMP_UEQ:   case CmpInst::FCMP_UGT: case CmpInst::FCMP_UGE:
2254   case CmpInst::FCMP_ULT:   case CmpInst::FCMP_ULE: case CmpInst::FCMP_UNE:
2255   case CmpInst::FCMP_TRUE:
2256     return getFCmp(Predicate, C1, C2, OnlyIfReduced);
2257
2258   case CmpInst::ICMP_EQ:  case CmpInst::ICMP_NE:  case CmpInst::ICMP_UGT:
2259   case CmpInst::ICMP_UGE: case CmpInst::ICMP_ULT: case CmpInst::ICMP_ULE:
2260   case CmpInst::ICMP_SGT: case CmpInst::ICMP_SGE: case CmpInst::ICMP_SLT:
2261   case CmpInst::ICMP_SLE:
2262     return getICmp(Predicate, C1, C2, OnlyIfReduced);
2263   }
2264 }
2265
2266 Constant *ConstantExpr::getGetElementPtr(Type *Ty, Constant *C,
2267                                          ArrayRef<Value *> Idxs, bool InBounds,
2268                                          std::optional<unsigned> InRangeIndex,
2269                                          Type *OnlyIfReducedTy) {
2270   assert(Ty && "Must specify element type");
2271   assert(isSupportedGetElementPtr(Ty) && "Element type is unsupported!");
2272
2273   if (Constant *FC =
2274           ConstantFoldGetElementPtr(Ty, C, InBounds, InRangeIndex, Idxs))
2275     return FC;          // Fold a few common cases.
2276
2277   assert(GetElementPtrInst::getIndexedType(Ty, Idxs) &&
2278          "GEP indices invalid!");;
2279
2280   // Get the result type of the getelementptr!
2281   Type *ReqTy = GetElementPtrInst::getGEPReturnType(C, Idxs);
2282   if (OnlyIfReducedTy == ReqTy)
2283     return nullptr;
2284
2285   auto EltCount = ElementCount::getFixed(0);
2286   if (VectorType *VecTy = dyn_cast<VectorType>(ReqTy))
2287     EltCount = VecTy->getElementCount();
2288
2289   // Look up the constant in the table first to ensure uniqueness
2290   std::vector<Constant*> ArgVec;
2291   ArgVec.reserve(1 + Idxs.size());
2292   ArgVec.push_back(C);
2293   auto GTI = gep_type_begin(Ty, Idxs), GTE = gep_type_end(Ty, Idxs);
2294   for (; GTI != GTE; ++GTI) {
2295     auto *Idx = cast<Constant>(GTI.getOperand());
2296     assert(
2297         (!isa<VectorType>(Idx->getType()) ||
2298          cast<VectorType>(Idx->getType())->getElementCount() == EltCount) &&
2299         "getelementptr index type missmatch");
2300
2301     if (GTI.isStruct() && Idx->getType()->isVectorTy()) {
2302       Idx = Idx->getSplatValue();
2303     } else if (GTI.isSequential() && EltCount.isNonZero() &&
2304                !Idx->getType()->isVectorTy()) {
2305       Idx = ConstantVector::getSplat(EltCount, Idx);
2306     }
2307     ArgVec.push_back(Idx);
2308   }
2309
2310   unsigned SubClassOptionalData = InBounds ? GEPOperator::IsInBounds : 0;
2311   if (InRangeIndex && *InRangeIndex < 63)
2312     SubClassOptionalData |= (*InRangeIndex + 1) << 1;
2313   const ConstantExprKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
2314                                 SubClassOptionalData, std::nullopt, Ty);
2315
2316   LLVMContextImpl *pImpl = C->getContext().pImpl;
2317   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2318 }
2319
2320 Constant *ConstantExpr::getICmp(unsigned short pred, Constant *LHS,
2321                                 Constant *RHS, bool OnlyIfReduced) {
2322   auto Predicate = static_cast<CmpInst::Predicate>(pred);
2323   assert(LHS->getType() == RHS->getType());
2324   assert(CmpInst::isIntPredicate(Predicate) && "Invalid ICmp Predicate");
2325
2326   if (Constant *FC = ConstantFoldCompareInstruction(Predicate, LHS, RHS))
2327     return FC;          // Fold a few common cases...
2328
2329   if (OnlyIfReduced)
2330     return nullptr;
2331
2332   // Look up the constant in the table first to ensure uniqueness
2333   Constant *ArgVec[] = { LHS, RHS };
2334   // Get the key type with both the opcode and predicate
2335   const ConstantExprKeyType Key(Instruction::ICmp, ArgVec, Predicate);
2336
2337   Type *ResultTy = Type::getInt1Ty(LHS->getContext());
2338   if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
2339     ResultTy = VectorType::get(ResultTy, VT->getElementCount());
2340
2341   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
2342   return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
2343 }
2344
2345 Constant *ConstantExpr::getFCmp(unsigned short pred, Constant *LHS,
2346                                 Constant *RHS, bool OnlyIfReduced) {
2347   auto Predicate = static_cast<CmpInst::Predicate>(pred);
2348   assert(LHS->getType() == RHS->getType());
2349   assert(CmpInst::isFPPredicate(Predicate) && "Invalid FCmp Predicate");
2350
2351   if (Constant *FC = ConstantFoldCompareInstruction(Predicate, LHS, RHS))
2352     return FC;          // Fold a few common cases...
2353
2354   if (OnlyIfReduced)
2355     return nullptr;
2356
2357   // Look up the constant in the table first to ensure uniqueness
2358   Constant *ArgVec[] = { LHS, RHS };
2359   // Get the key type with both the opcode and predicate
2360   const ConstantExprKeyType Key(Instruction::FCmp, ArgVec, Predicate);
2361
2362   Type *ResultTy = Type::getInt1Ty(LHS->getContext());
2363   if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
2364     ResultTy = VectorType::get(ResultTy, VT->getElementCount());
2365
2366   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
2367   return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
2368 }
2369
2370 Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx,
2371                                           Type *OnlyIfReducedTy) {
2372   assert(Val->getType()->isVectorTy() &&
2373          "Tried to create extractelement operation on non-vector type!");
2374   assert(Idx->getType()->isIntegerTy() &&
2375          "Extractelement index must be an integer type!");
2376
2377   if (Constant *FC = ConstantFoldExtractElementInstruction(Val, Idx))
2378     return FC;          // Fold a few common cases.
2379
2380   Type *ReqTy = cast<VectorType>(Val->getType())->getElementType();
2381   if (OnlyIfReducedTy == ReqTy)
2382     return nullptr;
2383
2384   // Look up the constant in the table first to ensure uniqueness
2385   Constant *ArgVec[] = { Val, Idx };
2386   const ConstantExprKeyType Key(Instruction::ExtractElement, ArgVec);
2387
2388   LLVMContextImpl *pImpl = Val->getContext().pImpl;
2389   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2390 }
2391
2392 Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
2393                                          Constant *Idx, Type *OnlyIfReducedTy) {
2394   assert(Val->getType()->isVectorTy() &&
2395          "Tried to create insertelement operation on non-vector type!");
2396   assert(Elt->getType() == cast<VectorType>(Val->getType())->getElementType() &&
2397          "Insertelement types must match!");
2398   assert(Idx->getType()->isIntegerTy() &&
2399          "Insertelement index must be i32 type!");
2400
2401   if (Constant *FC = ConstantFoldInsertElementInstruction(Val, Elt, Idx))
2402     return FC;          // Fold a few common cases.
2403
2404   if (OnlyIfReducedTy == Val->getType())
2405     return nullptr;
2406
2407   // Look up the constant in the table first to ensure uniqueness
2408   Constant *ArgVec[] = { Val, Elt, Idx };
2409   const ConstantExprKeyType Key(Instruction::InsertElement, ArgVec);
2410
2411   LLVMContextImpl *pImpl = Val->getContext().pImpl;
2412   return pImpl->ExprConstants.getOrCreate(Val->getType(), Key);
2413 }
2414
2415 Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
2416                                          ArrayRef<int> Mask,
2417                                          Type *OnlyIfReducedTy) {
2418   assert(ShuffleVectorInst::isValidOperands(V1, V2, Mask) &&
2419          "Invalid shuffle vector constant expr operands!");
2420
2421   if (Constant *FC = ConstantFoldShuffleVectorInstruction(V1, V2, Mask))
2422     return FC;          // Fold a few common cases.
2423
2424   unsigned NElts = Mask.size();
2425   auto V1VTy = cast<VectorType>(V1->getType());
2426   Type *EltTy = V1VTy->getElementType();
2427   bool TypeIsScalable = isa<ScalableVectorType>(V1VTy);
2428   Type *ShufTy = VectorType::get(EltTy, NElts, TypeIsScalable);
2429
2430   if (OnlyIfReducedTy == ShufTy)
2431     return nullptr;
2432
2433   // Look up the constant in the table first to ensure uniqueness
2434   Constant *ArgVec[] = {V1, V2};
2435   ConstantExprKeyType Key(Instruction::ShuffleVector, ArgVec, 0, 0, Mask);
2436
2437   LLVMContextImpl *pImpl = ShufTy->getContext().pImpl;
2438   return pImpl->ExprConstants.getOrCreate(ShufTy, Key);
2439 }
2440
2441 Constant *ConstantExpr::getNeg(Constant *C, bool HasNUW, bool HasNSW) {
2442   assert(C->getType()->isIntOrIntVectorTy() &&
2443          "Cannot NEG a nonintegral value!");
2444   return getSub(ConstantInt::get(C->getType(), 0), C, HasNUW, HasNSW);
2445 }
2446
2447 Constant *ConstantExpr::getNot(Constant *C) {
2448   assert(C->getType()->isIntOrIntVectorTy() &&
2449          "Cannot NOT a nonintegral value!");
2450   return get(Instruction::Xor, C, Constant::getAllOnesValue(C->getType()));
2451 }
2452
2453 Constant *ConstantExpr::getAdd(Constant *C1, Constant *C2,
2454                                bool HasNUW, bool HasNSW) {
2455   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2456                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2457   return get(Instruction::Add, C1, C2, Flags);
2458 }
2459
2460 Constant *ConstantExpr::getSub(Constant *C1, Constant *C2,
2461                                bool HasNUW, bool HasNSW) {
2462   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2463                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2464   return get(Instruction::Sub, C1, C2, Flags);
2465 }
2466
2467 Constant *ConstantExpr::getMul(Constant *C1, Constant *C2,
2468                                bool HasNUW, bool HasNSW) {
2469   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2470                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2471   return get(Instruction::Mul, C1, C2, Flags);
2472 }
2473
2474 Constant *ConstantExpr::getXor(Constant *C1, Constant *C2) {
2475   return get(Instruction::Xor, C1, C2);
2476 }
2477
2478 Constant *ConstantExpr::getShl(Constant *C1, Constant *C2,
2479                                bool HasNUW, bool HasNSW) {
2480   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2481                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2482   return get(Instruction::Shl, C1, C2, Flags);
2483 }
2484
2485 Constant *ConstantExpr::getExactLogBase2(Constant *C) {
2486   Type *Ty = C->getType();
2487   const APInt *IVal;
2488   if (match(C, m_APInt(IVal)) && IVal->isPowerOf2())
2489     return ConstantInt::get(Ty, IVal->logBase2());
2490
2491   // FIXME: We can extract pow of 2 of splat constant for scalable vectors.
2492   auto *VecTy = dyn_cast<FixedVectorType>(Ty);
2493   if (!VecTy)
2494     return nullptr;
2495
2496   SmallVector<Constant *, 4> Elts;
2497   for (unsigned I = 0, E = VecTy->getNumElements(); I != E; ++I) {
2498     Constant *Elt = C->getAggregateElement(I);
2499     if (!Elt)
2500       return nullptr;
2501     // Note that log2(iN undef) is *NOT* iN undef, because log2(iN undef) u< N.
2502     if (isa<UndefValue>(Elt)) {
2503       Elts.push_back(Constant::getNullValue(Ty->getScalarType()));
2504       continue;
2505     }
2506     if (!match(Elt, m_APInt(IVal)) || !IVal->isPowerOf2())
2507       return nullptr;
2508     Elts.push_back(ConstantInt::get(Ty->getScalarType(), IVal->logBase2()));
2509   }
2510
2511   return ConstantVector::get(Elts);
2512 }
2513
2514 Constant *ConstantExpr::getBinOpIdentity(unsigned Opcode, Type *Ty,
2515                                          bool AllowRHSConstant, bool NSZ) {
2516   assert(Instruction::isBinaryOp(Opcode) && "Only binops allowed");
2517
2518   // Commutative opcodes: it does not matter if AllowRHSConstant is set.
2519   if (Instruction::isCommutative(Opcode)) {
2520     switch (Opcode) {
2521       case Instruction::Add: // X + 0 = X
2522       case Instruction::Or:  // X | 0 = X
2523       case Instruction::Xor: // X ^ 0 = X
2524         return Constant::getNullValue(Ty);
2525       case Instruction::Mul: // X * 1 = X
2526         return ConstantInt::get(Ty, 1);
2527       case Instruction::And: // X & -1 = X
2528         return Constant::getAllOnesValue(Ty);
2529       case Instruction::FAdd: // X + -0.0 = X
2530         return ConstantFP::getZero(Ty, !NSZ);
2531       case Instruction::FMul: // X * 1.0 = X
2532         return ConstantFP::get(Ty, 1.0);
2533       default:
2534         llvm_unreachable("Every commutative binop has an identity constant");
2535     }
2536   }
2537
2538   // Non-commutative opcodes: AllowRHSConstant must be set.
2539   if (!AllowRHSConstant)
2540     return nullptr;
2541
2542   switch (Opcode) {
2543     case Instruction::Sub:  // X - 0 = X
2544     case Instruction::Shl:  // X << 0 = X
2545     case Instruction::LShr: // X >>u 0 = X
2546     case Instruction::AShr: // X >> 0 = X
2547     case Instruction::FSub: // X - 0.0 = X
2548       return Constant::getNullValue(Ty);
2549     case Instruction::SDiv: // X / 1 = X
2550     case Instruction::UDiv: // X /u 1 = X
2551       return ConstantInt::get(Ty, 1);
2552     case Instruction::FDiv: // X / 1.0 = X
2553       return ConstantFP::get(Ty, 1.0);
2554     default:
2555       return nullptr;
2556   }
2557 }
2558
2559 Constant *ConstantExpr::getIntrinsicIdentity(Intrinsic::ID ID, Type *Ty) {
2560   switch (ID) {
2561   case Intrinsic::umax:
2562     return Constant::getNullValue(Ty);
2563   case Intrinsic::umin:
2564     return Constant::getAllOnesValue(Ty);
2565   case Intrinsic::smax:
2566     return Constant::getIntegerValue(
2567         Ty, APInt::getSignedMinValue(Ty->getIntegerBitWidth()));
2568   case Intrinsic::smin:
2569     return Constant::getIntegerValue(
2570         Ty, APInt::getSignedMaxValue(Ty->getIntegerBitWidth()));
2571   default:
2572     return nullptr;
2573   }
2574 }
2575
2576 Constant *ConstantExpr::getIdentity(Instruction *I, Type *Ty,
2577                                     bool AllowRHSConstant, bool NSZ) {
2578   if (I->isBinaryOp())
2579     return getBinOpIdentity(I->getOpcode(), Ty, AllowRHSConstant, NSZ);
2580   if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
2581     return getIntrinsicIdentity(II->getIntrinsicID(), Ty);
2582   return nullptr;
2583 }
2584
2585 Constant *ConstantExpr::getBinOpAbsorber(unsigned Opcode, Type *Ty) {
2586   switch (Opcode) {
2587   default:
2588     // Doesn't have an absorber.
2589     return nullptr;
2590
2591   case Instruction::Or:
2592     return Constant::getAllOnesValue(Ty);
2593
2594   case Instruction::And:
2595   case Instruction::Mul:
2596     return Constant::getNullValue(Ty);
2597   }
2598 }
2599
2600 /// Remove the constant from the constant table.
2601 void ConstantExpr::destroyConstantImpl() {
2602   getType()->getContext().pImpl->ExprConstants.remove(this);
2603 }
2604
2605 const char *ConstantExpr::getOpcodeName() const {
2606   return Instruction::getOpcodeName(getOpcode());
2607 }
2608
2609 GetElementPtrConstantExpr::GetElementPtrConstantExpr(
2610     Type *SrcElementTy, Constant *C, ArrayRef<Constant *> IdxList, Type *DestTy)
2611     : ConstantExpr(DestTy, Instruction::GetElementPtr,
2612                    OperandTraits<GetElementPtrConstantExpr>::op_end(this) -
2613                        (IdxList.size() + 1),
2614                    IdxList.size() + 1),
2615       SrcElementTy(SrcElementTy),
2616       ResElementTy(GetElementPtrInst::getIndexedType(SrcElementTy, IdxList)) {
2617   Op<0>() = C;
2618   Use *OperandList = getOperandList();
2619   for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
2620     OperandList[i+1] = IdxList[i];
2621 }
2622
2623 Type *GetElementPtrConstantExpr::getSourceElementType() const {
2624   return SrcElementTy;
2625 }
2626
2627 Type *GetElementPtrConstantExpr::getResultElementType() const {
2628   return ResElementTy;
2629 }
2630
2631 //===----------------------------------------------------------------------===//
2632 //                       ConstantData* implementations
2633
2634 Type *ConstantDataSequential::getElementType() const {
2635   if (ArrayType *ATy = dyn_cast<ArrayType>(getType()))
2636     return ATy->getElementType();
2637   return cast<VectorType>(getType())->getElementType();
2638 }
2639
2640 StringRef ConstantDataSequential::getRawDataValues() const {
2641   return StringRef(DataElements, getNumElements()*getElementByteSize());
2642 }
2643
2644 bool ConstantDataSequential::isElementTypeCompatible(Type *Ty) {
2645   if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() || Ty->isDoubleTy())
2646     return true;
2647   if (auto *IT = dyn_cast<IntegerType>(Ty)) {
2648     switch (IT->getBitWidth()) {
2649     case 8:
2650     case 16:
2651     case 32:
2652     case 64:
2653       return true;
2654     default: break;
2655     }
2656   }
2657   return false;
2658 }
2659
2660 unsigned ConstantDataSequential::getNumElements() const {
2661   if (ArrayType *AT = dyn_cast<ArrayType>(getType()))
2662     return AT->getNumElements();
2663   return cast<FixedVectorType>(getType())->getNumElements();
2664 }
2665
2666
2667 uint64_t ConstantDataSequential::getElementByteSize() const {
2668   return getElementType()->getPrimitiveSizeInBits()/8;
2669 }
2670
2671 /// Return the start of the specified element.
2672 const char *ConstantDataSequential::getElementPointer(unsigned Elt) const {
2673   assert(Elt < getNumElements() && "Invalid Elt");
2674   return DataElements+Elt*getElementByteSize();
2675 }
2676
2677
2678 /// Return true if the array is empty or all zeros.
2679 static bool isAllZeros(StringRef Arr) {
2680   for (char I : Arr)
2681     if (I != 0)
2682       return false;
2683   return true;
2684 }
2685
2686 /// This is the underlying implementation of all of the
2687 /// ConstantDataSequential::get methods.  They all thunk down to here, providing
2688 /// the correct element type.  We take the bytes in as a StringRef because
2689 /// we *want* an underlying "char*" to avoid TBAA type punning violations.
2690 Constant *ConstantDataSequential::getImpl(StringRef Elements, Type *Ty) {
2691 #ifndef NDEBUG
2692   if (ArrayType *ATy = dyn_cast<ArrayType>(Ty))
2693     assert(isElementTypeCompatible(ATy->getElementType()));
2694   else
2695     assert(isElementTypeCompatible(cast<VectorType>(Ty)->getElementType()));
2696 #endif
2697   // If the elements are all zero or there are no elements, return a CAZ, which
2698   // is more dense and canonical.
2699   if (isAllZeros(Elements))
2700     return ConstantAggregateZero::get(Ty);
2701
2702   // Do a lookup to see if we have already formed one of these.
2703   auto &Slot =
2704       *Ty->getContext()
2705            .pImpl->CDSConstants.insert(std::make_pair(Elements, nullptr))
2706            .first;
2707
2708   // The bucket can point to a linked list of different CDS's that have the same
2709   // body but different types.  For example, 0,0,0,1 could be a 4 element array
2710   // of i8, or a 1-element array of i32.  They'll both end up in the same
2711   /// StringMap bucket, linked up by their Next pointers.  Walk the list.
2712   std::unique_ptr<ConstantDataSequential> *Entry = &Slot.second;
2713   for (; *Entry; Entry = &(*Entry)->Next)
2714     if ((*Entry)->getType() == Ty)
2715       return Entry->get();
2716
2717   // Okay, we didn't get a hit.  Create a node of the right class, link it in,
2718   // and return it.
2719   if (isa<ArrayType>(Ty)) {
2720     // Use reset because std::make_unique can't access the constructor.
2721     Entry->reset(new ConstantDataArray(Ty, Slot.first().data()));
2722     return Entry->get();
2723   }
2724
2725   assert(isa<VectorType>(Ty));
2726   // Use reset because std::make_unique can't access the constructor.
2727   Entry->reset(new ConstantDataVector(Ty, Slot.first().data()));
2728   return Entry->get();
2729 }
2730
2731 void ConstantDataSequential::destroyConstantImpl() {
2732   // Remove the constant from the StringMap.
2733   StringMap<std::unique_ptr<ConstantDataSequential>> &CDSConstants =
2734       getType()->getContext().pImpl->CDSConstants;
2735
2736   auto Slot = CDSConstants.find(getRawDataValues());
2737
2738   assert(Slot != CDSConstants.end() && "CDS not found in uniquing table");
2739
2740   std::unique_ptr<ConstantDataSequential> *Entry = &Slot->getValue();
2741
2742   // Remove the entry from the hash table.
2743   if (!(*Entry)->Next) {
2744     // If there is only one value in the bucket (common case) it must be this
2745     // entry, and removing the entry should remove the bucket completely.
2746     assert(Entry->get() == this && "Hash mismatch in ConstantDataSequential");
2747     getContext().pImpl->CDSConstants.erase(Slot);
2748     return;
2749   }
2750
2751   // Otherwise, there are multiple entries linked off the bucket, unlink the
2752   // node we care about but keep the bucket around.
2753   while (true) {
2754     std::unique_ptr<ConstantDataSequential> &Node = *Entry;
2755     assert(Node && "Didn't find entry in its uniquing hash table!");
2756     // If we found our entry, unlink it from the list and we're done.
2757     if (Node.get() == this) {
2758       Node = std::move(Node->Next);
2759       return;
2760     }
2761
2762     Entry = &Node->Next;
2763   }
2764 }
2765
2766 /// getFP() constructors - Return a constant of array type with a float
2767 /// element type taken from argument `ElementType', and count taken from
2768 /// argument `Elts'.  The amount of bits of the contained type must match the
2769 /// number of bits of the type contained in the passed in ArrayRef.
2770 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note
2771 /// that this can return a ConstantAggregateZero object.
2772 Constant *ConstantDataArray::getFP(Type *ElementType, ArrayRef<uint16_t> Elts) {
2773   assert((ElementType->isHalfTy() || ElementType->isBFloatTy()) &&
2774          "Element type is not a 16-bit float type");
2775   Type *Ty = ArrayType::get(ElementType, Elts.size());
2776   const char *Data = reinterpret_cast<const char *>(Elts.data());
2777   return getImpl(StringRef(Data, Elts.size() * 2), Ty);
2778 }
2779 Constant *ConstantDataArray::getFP(Type *ElementType, ArrayRef<uint32_t> Elts) {
2780   assert(ElementType->isFloatTy() && "Element type is not a 32-bit float type");
2781   Type *Ty = ArrayType::get(ElementType, Elts.size());
2782   const char *Data = reinterpret_cast<const char *>(Elts.data());
2783   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2784 }
2785 Constant *ConstantDataArray::getFP(Type *ElementType, ArrayRef<uint64_t> Elts) {
2786   assert(ElementType->isDoubleTy() &&
2787          "Element type is not a 64-bit float type");
2788   Type *Ty = ArrayType::get(ElementType, Elts.size());
2789   const char *Data = reinterpret_cast<const char *>(Elts.data());
2790   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2791 }
2792
2793 Constant *ConstantDataArray::getString(LLVMContext &Context,
2794                                        StringRef Str, bool AddNull) {
2795   if (!AddNull) {
2796     const uint8_t *Data = Str.bytes_begin();
2797     return get(Context, ArrayRef(Data, Str.size()));
2798   }
2799
2800   SmallVector<uint8_t, 64> ElementVals;
2801   ElementVals.append(Str.begin(), Str.end());
2802   ElementVals.push_back(0);
2803   return get(Context, ElementVals);
2804 }
2805
2806 /// get() constructors - Return a constant with vector type with an element
2807 /// count and element type matching the ArrayRef passed in.  Note that this
2808 /// can return a ConstantAggregateZero object.
2809 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint8_t> Elts){
2810   auto *Ty = FixedVectorType::get(Type::getInt8Ty(Context), Elts.size());
2811   const char *Data = reinterpret_cast<const char *>(Elts.data());
2812   return getImpl(StringRef(Data, Elts.size() * 1), Ty);
2813 }
2814 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
2815   auto *Ty = FixedVectorType::get(Type::getInt16Ty(Context), Elts.size());
2816   const char *Data = reinterpret_cast<const char *>(Elts.data());
2817   return getImpl(StringRef(Data, Elts.size() * 2), Ty);
2818 }
2819 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
2820   auto *Ty = FixedVectorType::get(Type::getInt32Ty(Context), Elts.size());
2821   const char *Data = reinterpret_cast<const char *>(Elts.data());
2822   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2823 }
2824 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
2825   auto *Ty = FixedVectorType::get(Type::getInt64Ty(Context), Elts.size());
2826   const char *Data = reinterpret_cast<const char *>(Elts.data());
2827   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2828 }
2829 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<float> Elts) {
2830   auto *Ty = FixedVectorType::get(Type::getFloatTy(Context), Elts.size());
2831   const char *Data = reinterpret_cast<const char *>(Elts.data());
2832   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2833 }
2834 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<double> Elts) {
2835   auto *Ty = FixedVectorType::get(Type::getDoubleTy(Context), Elts.size());
2836   const char *Data = reinterpret_cast<const char *>(Elts.data());
2837   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2838 }
2839
2840 /// getFP() constructors - Return a constant of vector type with a float
2841 /// element type taken from argument `ElementType', and count taken from
2842 /// argument `Elts'.  The amount of bits of the contained type must match the
2843 /// number of bits of the type contained in the passed in ArrayRef.
2844 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note
2845 /// that this can return a ConstantAggregateZero object.
2846 Constant *ConstantDataVector::getFP(Type *ElementType,
2847                                     ArrayRef<uint16_t> Elts) {
2848   assert((ElementType->isHalfTy() || ElementType->isBFloatTy()) &&
2849          "Element type is not a 16-bit float type");
2850   auto *Ty = FixedVectorType::get(ElementType, Elts.size());
2851   const char *Data = reinterpret_cast<const char *>(Elts.data());
2852   return getImpl(StringRef(Data, Elts.size() * 2), Ty);
2853 }
2854 Constant *ConstantDataVector::getFP(Type *ElementType,
2855                                     ArrayRef<uint32_t> Elts) {
2856   assert(ElementType->isFloatTy() && "Element type is not a 32-bit float type");
2857   auto *Ty = FixedVectorType::get(ElementType, Elts.size());
2858   const char *Data = reinterpret_cast<const char *>(Elts.data());
2859   return getImpl(StringRef(Data, Elts.size() * 4), Ty);
2860 }
2861 Constant *ConstantDataVector::getFP(Type *ElementType,
2862                                     ArrayRef<uint64_t> Elts) {
2863   assert(ElementType->isDoubleTy() &&
2864          "Element type is not a 64-bit float type");
2865   auto *Ty = FixedVectorType::get(ElementType, Elts.size());
2866   const char *Data = reinterpret_cast<const char *>(Elts.data());
2867   return getImpl(StringRef(Data, Elts.size() * 8), Ty);
2868 }
2869
2870 Constant *ConstantDataVector::getSplat(unsigned NumElts, Constant *V) {
2871   assert(isElementTypeCompatible(V->getType()) &&
2872          "Element type not compatible with ConstantData");
2873   if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
2874     if (CI->getType()->isIntegerTy(8)) {
2875       SmallVector<uint8_t, 16> Elts(NumElts, CI->getZExtValue());
2876       return get(V->getContext(), Elts);
2877     }
2878     if (CI->getType()->isIntegerTy(16)) {
2879       SmallVector<uint16_t, 16> Elts(NumElts, CI->getZExtValue());
2880       return get(V->getContext(), Elts);
2881     }
2882     if (CI->getType()->isIntegerTy(32)) {
2883       SmallVector<uint32_t, 16> Elts(NumElts, CI->getZExtValue());
2884       return get(V->getContext(), Elts);
2885     }
2886     assert(CI->getType()->isIntegerTy(64) && "Unsupported ConstantData type");
2887     SmallVector<uint64_t, 16> Elts(NumElts, CI->getZExtValue());
2888     return get(V->getContext(), Elts);
2889   }
2890
2891   if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
2892     if (CFP->getType()->isHalfTy()) {
2893       SmallVector<uint16_t, 16> Elts(
2894           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2895       return getFP(V->getType(), Elts);
2896     }
2897     if (CFP->getType()->isBFloatTy()) {
2898       SmallVector<uint16_t, 16> Elts(
2899           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2900       return getFP(V->getType(), Elts);
2901     }
2902     if (CFP->getType()->isFloatTy()) {
2903       SmallVector<uint32_t, 16> Elts(
2904           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2905       return getFP(V->getType(), Elts);
2906     }
2907     if (CFP->getType()->isDoubleTy()) {
2908       SmallVector<uint64_t, 16> Elts(
2909           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2910       return getFP(V->getType(), Elts);
2911     }
2912   }
2913   return ConstantVector::getSplat(ElementCount::getFixed(NumElts), V);
2914 }
2915
2916
2917 uint64_t ConstantDataSequential::getElementAsInteger(unsigned Elt) const {
2918   assert(isa<IntegerType>(getElementType()) &&
2919          "Accessor can only be used when element is an integer");
2920   const char *EltPtr = getElementPointer(Elt);
2921
2922   // The data is stored in host byte order, make sure to cast back to the right
2923   // type to load with the right endianness.
2924   switch (getElementType()->getIntegerBitWidth()) {
2925   default: llvm_unreachable("Invalid bitwidth for CDS");
2926   case 8:
2927     return *reinterpret_cast<const uint8_t *>(EltPtr);
2928   case 16:
2929     return *reinterpret_cast<const uint16_t *>(EltPtr);
2930   case 32:
2931     return *reinterpret_cast<const uint32_t *>(EltPtr);
2932   case 64:
2933     return *reinterpret_cast<const uint64_t *>(EltPtr);
2934   }
2935 }
2936
2937 APInt ConstantDataSequential::getElementAsAPInt(unsigned Elt) const {
2938   assert(isa<IntegerType>(getElementType()) &&
2939          "Accessor can only be used when element is an integer");
2940   const char *EltPtr = getElementPointer(Elt);
2941
2942   // The data is stored in host byte order, make sure to cast back to the right
2943   // type to load with the right endianness.
2944   switch (getElementType()->getIntegerBitWidth()) {
2945   default: llvm_unreachable("Invalid bitwidth for CDS");
2946   case 8: {
2947     auto EltVal = *reinterpret_cast<const uint8_t *>(EltPtr);
2948     return APInt(8, EltVal);
2949   }
2950   case 16: {
2951     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
2952     return APInt(16, EltVal);
2953   }
2954   case 32: {
2955     auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
2956     return APInt(32, EltVal);
2957   }
2958   case 64: {
2959     auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
2960     return APInt(64, EltVal);
2961   }
2962   }
2963 }
2964
2965 APFloat ConstantDataSequential::getElementAsAPFloat(unsigned Elt) const {
2966   const char *EltPtr = getElementPointer(Elt);
2967
2968   switch (getElementType()->getTypeID()) {
2969   default:
2970     llvm_unreachable("Accessor can only be used when element is float/double!");
2971   case Type::HalfTyID: {
2972     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
2973     return APFloat(APFloat::IEEEhalf(), APInt(16, EltVal));
2974   }
2975   case Type::BFloatTyID: {
2976     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
2977     return APFloat(APFloat::BFloat(), APInt(16, EltVal));
2978   }
2979   case Type::FloatTyID: {
2980     auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
2981     return APFloat(APFloat::IEEEsingle(), APInt(32, EltVal));
2982   }
2983   case Type::DoubleTyID: {
2984     auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
2985     return APFloat(APFloat::IEEEdouble(), APInt(64, EltVal));
2986   }
2987   }
2988 }
2989
2990 float ConstantDataSequential::getElementAsFloat(unsigned Elt) const {
2991   assert(getElementType()->isFloatTy() &&
2992          "Accessor can only be used when element is a 'float'");
2993   return *reinterpret_cast<const float *>(getElementPointer(Elt));
2994 }
2995
2996 double ConstantDataSequential::getElementAsDouble(unsigned Elt) const {
2997   assert(getElementType()->isDoubleTy() &&
2998          "Accessor can only be used when element is a 'float'");
2999   return *reinterpret_cast<const double *>(getElementPointer(Elt));
3000 }
3001
3002 Constant *ConstantDataSequential::getElementAsConstant(unsigned Elt) const {
3003   if (getElementType()->isHalfTy() || getElementType()->isBFloatTy() ||
3004       getElementType()->isFloatTy() || getElementType()->isDoubleTy())
3005     return ConstantFP::get(getContext(), getElementAsAPFloat(Elt));
3006
3007   return ConstantInt::get(getElementType(), getElementAsInteger(Elt));
3008 }
3009
3010 bool ConstantDataSequential::isString(unsigned CharSize) const {
3011   return isa<ArrayType>(getType()) && getElementType()->isIntegerTy(CharSize);
3012 }
3013
3014 bool ConstantDataSequential::isCString() const {
3015   if (!isString())
3016     return false;
3017
3018   StringRef Str = getAsString();
3019
3020   // The last value must be nul.
3021   if (Str.back() != 0) return false;
3022
3023   // Other elements must be non-nul.
3024   return !Str.drop_back().contains(0);
3025 }
3026
3027 bool ConstantDataVector::isSplatData() const {
3028   const char *Base = getRawDataValues().data();
3029
3030   // Compare elements 1+ to the 0'th element.
3031   unsigned EltSize = getElementByteSize();
3032   for (unsigned i = 1, e = getNumElements(); i != e; ++i)
3033     if (memcmp(Base, Base+i*EltSize, EltSize))
3034       return false;
3035
3036   return true;
3037 }
3038
3039 bool ConstantDataVector::isSplat() const {
3040   if (!IsSplatSet) {
3041     IsSplatSet = true;
3042     IsSplat = isSplatData();
3043   }
3044   return IsSplat;
3045 }
3046
3047 Constant *ConstantDataVector::getSplatValue() const {
3048   // If they're all the same, return the 0th one as a representative.
3049   return isSplat() ? getElementAsConstant(0) : nullptr;
3050 }
3051
3052 //===----------------------------------------------------------------------===//
3053 //                handleOperandChange implementations
3054
3055 /// Update this constant array to change uses of
3056 /// 'From' to be uses of 'To'.  This must update the uniquing data structures
3057 /// etc.
3058 ///
3059 /// Note that we intentionally replace all uses of From with To here.  Consider
3060 /// a large array that uses 'From' 1000 times.  By handling this case all here,
3061 /// ConstantArray::handleOperandChange is only invoked once, and that
3062 /// single invocation handles all 1000 uses.  Handling them one at a time would
3063 /// work, but would be really slow because it would have to unique each updated
3064 /// array instance.
3065 ///
3066 void Constant::handleOperandChange(Value *From, Value *To) {
3067   Value *Replacement = nullptr;
3068   switch (getValueID()) {
3069   default:
3070     llvm_unreachable("Not a constant!");
3071 #define HANDLE_CONSTANT(Name)                                                  \
3072   case Value::Name##Val:                                                       \
3073     Replacement = cast<Name>(this)->handleOperandChangeImpl(From, To);         \
3074     break;
3075 #include "llvm/IR/Value.def"
3076   }
3077
3078   // If handleOperandChangeImpl returned nullptr, then it handled
3079   // replacing itself and we don't want to delete or replace anything else here.
3080   if (!Replacement)
3081     return;
3082
3083   // I do need to replace this with an existing value.
3084   assert(Replacement != this && "I didn't contain From!");
3085
3086   // Everyone using this now uses the replacement.
3087   replaceAllUsesWith(Replacement);
3088
3089   // Delete the old constant!
3090   destroyConstant();
3091 }
3092
3093 Value *ConstantArray::handleOperandChangeImpl(Value *From, Value *To) {
3094   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
3095   Constant *ToC = cast<Constant>(To);
3096
3097   SmallVector<Constant*, 8> Values;
3098   Values.reserve(getNumOperands());  // Build replacement array.
3099
3100   // Fill values with the modified operands of the constant array.  Also,
3101   // compute whether this turns into an all-zeros array.
3102   unsigned NumUpdated = 0;
3103
3104   // Keep track of whether all the values in the array are "ToC".
3105   bool AllSame = true;
3106   Use *OperandList = getOperandList();
3107   unsigned OperandNo = 0;
3108   for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
3109     Constant *Val = cast<Constant>(O->get());
3110     if (Val == From) {
3111       OperandNo = (O - OperandList);
3112       Val = ToC;
3113       ++NumUpdated;
3114     }
3115     Values.push_back(Val);
3116     AllSame &= Val == ToC;
3117   }
3118
3119   if (AllSame && ToC->isNullValue())
3120     return ConstantAggregateZero::get(getType());
3121
3122   if (AllSame && isa<UndefValue>(ToC))
3123     return UndefValue::get(getType());
3124
3125   // Check for any other type of constant-folding.
3126   if (Constant *C = getImpl(getType(), Values))
3127     return C;
3128
3129   // Update to the new value.
3130   return getContext().pImpl->ArrayConstants.replaceOperandsInPlace(
3131       Values, this, From, ToC, NumUpdated, OperandNo);
3132 }
3133
3134 Value *ConstantStruct::handleOperandChangeImpl(Value *From, Value *To) {
3135   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
3136   Constant *ToC = cast<Constant>(To);
3137
3138   Use *OperandList = getOperandList();
3139
3140   SmallVector<Constant*, 8> Values;
3141   Values.reserve(getNumOperands());  // Build replacement struct.
3142
3143   // Fill values with the modified operands of the constant struct.  Also,
3144   // compute whether this turns into an all-zeros struct.
3145   unsigned NumUpdated = 0;
3146   bool AllSame = true;
3147   unsigned OperandNo = 0;
3148   for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O) {
3149     Constant *Val = cast<Constant>(O->get());
3150     if (Val == From) {
3151       OperandNo = (O - OperandList);
3152       Val = ToC;
3153       ++NumUpdated;
3154     }
3155     Values.push_back(Val);
3156     AllSame &= Val == ToC;
3157   }
3158
3159   if (AllSame && ToC->isNullValue())
3160     return ConstantAggregateZero::get(getType());
3161
3162   if (AllSame && isa<UndefValue>(ToC))
3163     return UndefValue::get(getType());
3164
3165   // Update to the new value.
3166   return getContext().pImpl->StructConstants.replaceOperandsInPlace(
3167       Values, this, From, ToC, NumUpdated, OperandNo);
3168 }
3169
3170 Value *ConstantVector::handleOperandChangeImpl(Value *From, Value *To) {
3171   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
3172   Constant *ToC = cast<Constant>(To);
3173
3174   SmallVector<Constant*, 8> Values;
3175   Values.reserve(getNumOperands());  // Build replacement array...
3176   unsigned NumUpdated = 0;
3177   unsigned OperandNo = 0;
3178   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
3179     Constant *Val = getOperand(i);
3180     if (Val == From) {
3181       OperandNo = i;
3182       ++NumUpdated;
3183       Val = ToC;
3184     }
3185     Values.push_back(Val);
3186   }
3187
3188   if (Constant *C = getImpl(Values))
3189     return C;
3190
3191   // Update to the new value.
3192   return getContext().pImpl->VectorConstants.replaceOperandsInPlace(
3193       Values, this, From, ToC, NumUpdated, OperandNo);
3194 }
3195
3196 Value *ConstantExpr::handleOperandChangeImpl(Value *From, Value *ToV) {
3197   assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
3198   Constant *To = cast<Constant>(ToV);
3199
3200   SmallVector<Constant*, 8> NewOps;
3201   unsigned NumUpdated = 0;
3202   unsigned OperandNo = 0;
3203   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
3204     Constant *Op = getOperand(i);
3205     if (Op == From) {
3206       OperandNo = i;
3207       ++NumUpdated;
3208       Op = To;
3209     }
3210     NewOps.push_back(Op);
3211   }
3212   assert(NumUpdated && "I didn't contain From!");
3213
3214   if (Constant *C = getWithOperands(NewOps, getType(), true))
3215     return C;
3216
3217   // Update to the new value.
3218   return getContext().pImpl->ExprConstants.replaceOperandsInPlace(
3219       NewOps, this, From, To, NumUpdated, OperandNo);
3220 }
3221
3222 Instruction *ConstantExpr::getAsInstruction(Instruction *InsertBefore) const {
3223   SmallVector<Value *, 4> ValueOperands(operands());
3224   ArrayRef<Value*> Ops(ValueOperands);
3225
3226   switch (getOpcode()) {
3227   case Instruction::Trunc:
3228   case Instruction::ZExt:
3229   case Instruction::SExt:
3230   case Instruction::FPTrunc:
3231   case Instruction::FPExt:
3232   case Instruction::UIToFP:
3233   case Instruction::SIToFP:
3234   case Instruction::FPToUI:
3235   case Instruction::FPToSI:
3236   case Instruction::PtrToInt:
3237   case Instruction::IntToPtr:
3238   case Instruction::BitCast:
3239   case Instruction::AddrSpaceCast:
3240     return CastInst::Create((Instruction::CastOps)getOpcode(), Ops[0],
3241                             getType(), "", InsertBefore);
3242   case Instruction::InsertElement:
3243     return InsertElementInst::Create(Ops[0], Ops[1], Ops[2], "", InsertBefore);
3244   case Instruction::ExtractElement:
3245     return ExtractElementInst::Create(Ops[0], Ops[1], "", InsertBefore);
3246   case Instruction::ShuffleVector:
3247     return new ShuffleVectorInst(Ops[0], Ops[1], getShuffleMask(), "",
3248                                  InsertBefore);
3249
3250   case Instruction::GetElementPtr: {
3251     const auto *GO = cast<GEPOperator>(this);
3252     if (GO->isInBounds())
3253       return GetElementPtrInst::CreateInBounds(
3254           GO->getSourceElementType(), Ops[0], Ops.slice(1), "", InsertBefore);
3255     return GetElementPtrInst::Create(GO->getSourceElementType(), Ops[0],
3256                                      Ops.slice(1), "", InsertBefore);
3257   }
3258   case Instruction::ICmp:
3259   case Instruction::FCmp:
3260     return CmpInst::Create((Instruction::OtherOps)getOpcode(),
3261                            (CmpInst::Predicate)getPredicate(), Ops[0], Ops[1],
3262                            "", InsertBefore);
3263   default:
3264     assert(getNumOperands() == 2 && "Must be binary operator?");
3265     BinaryOperator *BO = BinaryOperator::Create(
3266         (Instruction::BinaryOps)getOpcode(), Ops[0], Ops[1], "", InsertBefore);
3267     if (isa<OverflowingBinaryOperator>(BO)) {
3268       BO->setHasNoUnsignedWrap(SubclassOptionalData &
3269                                OverflowingBinaryOperator::NoUnsignedWrap);
3270       BO->setHasNoSignedWrap(SubclassOptionalData &
3271                              OverflowingBinaryOperator::NoSignedWrap);
3272     }
3273     if (isa<PossiblyExactOperator>(BO))
3274       BO->setIsExact(SubclassOptionalData & PossiblyExactOperator::IsExact);
3275     return BO;
3276   }
3277 }