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1 //===-- Constants.cpp - Implement Constant nodes --------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the Constant* classes.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/IR/Constants.h"
15 #include "ConstantFold.h"
16 #include "LLVMContextImpl.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/IR/DerivedTypes.h"
22 #include "llvm/IR/GetElementPtrTypeIterator.h"
23 #include "llvm/IR/GlobalValue.h"
24 #include "llvm/IR/Instructions.h"
25 #include "llvm/IR/Module.h"
26 #include "llvm/IR/Operator.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/ManagedStatic.h"
30 #include "llvm/Support/MathExtras.h"
31 #include "llvm/Support/raw_ostream.h"
32 #include <algorithm>
33 #include <cstdarg>
34 using namespace llvm;
35 
36 //===----------------------------------------------------------------------===//
37 //                              Constant Class
38 //===----------------------------------------------------------------------===//
39 
anchor()40 void Constant::anchor() { }
41 
anchor()42 void ConstantData::anchor() {}
43 
isNegativeZeroValue() const44 bool Constant::isNegativeZeroValue() const {
45   // Floating point values have an explicit -0.0 value.
46   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
47     return CFP->isZero() && CFP->isNegative();
48 
49   // Equivalent for a vector of -0.0's.
50   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
51     if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
52       if (SplatCFP && SplatCFP->isZero() && SplatCFP->isNegative())
53         return true;
54 
55   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
56     if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
57       if (SplatCFP && SplatCFP->isZero() && SplatCFP->isNegative())
58         return true;
59 
60   // We've already handled true FP case; any other FP vectors can't represent -0.0.
61   if (getType()->isFPOrFPVectorTy())
62     return false;
63 
64   // Otherwise, just use +0.0.
65   return isNullValue();
66 }
67 
68 // Return true iff this constant is positive zero (floating point), negative
69 // zero (floating point), or a null value.
isZeroValue() const70 bool Constant::isZeroValue() const {
71   // Floating point values have an explicit -0.0 value.
72   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
73     return CFP->isZero();
74 
75   // Equivalent for a vector of -0.0's.
76   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
77     if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
78       if (SplatCFP && SplatCFP->isZero())
79         return true;
80 
81   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
82     if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
83       if (SplatCFP && SplatCFP->isZero())
84         return true;
85 
86   // Otherwise, just use +0.0.
87   return isNullValue();
88 }
89 
isNullValue() const90 bool Constant::isNullValue() const {
91   // 0 is null.
92   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
93     return CI->isZero();
94 
95   // +0.0 is null.
96   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
97     return CFP->isZero() && !CFP->isNegative();
98 
99   // constant zero is zero for aggregates, cpnull is null for pointers, none for
100   // tokens.
101   return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this) ||
102          isa<ConstantTokenNone>(this);
103 }
104 
isAllOnesValue() const105 bool Constant::isAllOnesValue() const {
106   // Check for -1 integers
107   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
108     return CI->isMinusOne();
109 
110   // Check for FP which are bitcasted from -1 integers
111   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
112     return CFP->getValueAPF().bitcastToAPInt().isAllOnesValue();
113 
114   // Check for constant vectors which are splats of -1 values.
115   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
116     if (Constant *Splat = CV->getSplatValue())
117       return Splat->isAllOnesValue();
118 
119   // Check for constant vectors which are splats of -1 values.
120   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
121     if (Constant *Splat = CV->getSplatValue())
122       return Splat->isAllOnesValue();
123 
124   return false;
125 }
126 
isOneValue() const127 bool Constant::isOneValue() const {
128   // Check for 1 integers
129   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
130     return CI->isOne();
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() == 1;
135 
136   // Check for constant vectors which are splats of 1 values.
137   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
138     if (Constant *Splat = CV->getSplatValue())
139       return Splat->isOneValue();
140 
141   // Check for constant vectors which are splats of 1 values.
142   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
143     if (Constant *Splat = CV->getSplatValue())
144       return Splat->isOneValue();
145 
146   return false;
147 }
148 
isMinSignedValue() const149 bool Constant::isMinSignedValue() const {
150   // Check for INT_MIN integers
151   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
152     return CI->isMinValue(/*isSigned=*/true);
153 
154   // Check for FP which are bitcasted from INT_MIN integers
155   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
156     return CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
157 
158   // Check for constant vectors which are splats of INT_MIN values.
159   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
160     if (Constant *Splat = CV->getSplatValue())
161       return Splat->isMinSignedValue();
162 
163   // Check for constant vectors which are splats of INT_MIN values.
164   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
165     if (Constant *Splat = CV->getSplatValue())
166       return Splat->isMinSignedValue();
167 
168   return false;
169 }
170 
isNotMinSignedValue() const171 bool Constant::isNotMinSignedValue() const {
172   // Check for INT_MIN integers
173   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
174     return !CI->isMinValue(/*isSigned=*/true);
175 
176   // Check for FP which are bitcasted from INT_MIN integers
177   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
178     return !CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
179 
180   // Check for constant vectors which are splats of INT_MIN values.
181   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
182     if (Constant *Splat = CV->getSplatValue())
183       return Splat->isNotMinSignedValue();
184 
185   // Check for constant vectors which are splats of INT_MIN values.
186   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
187     if (Constant *Splat = CV->getSplatValue())
188       return Splat->isNotMinSignedValue();
189 
190   // It *may* contain INT_MIN, we can't tell.
191   return false;
192 }
193 
194 /// Constructor to create a '0' constant of arbitrary type.
getNullValue(Type * Ty)195 Constant *Constant::getNullValue(Type *Ty) {
196   switch (Ty->getTypeID()) {
197   case Type::IntegerTyID:
198     return ConstantInt::get(Ty, 0);
199   case Type::HalfTyID:
200     return ConstantFP::get(Ty->getContext(),
201                            APFloat::getZero(APFloat::IEEEhalf));
202   case Type::FloatTyID:
203     return ConstantFP::get(Ty->getContext(),
204                            APFloat::getZero(APFloat::IEEEsingle));
205   case Type::DoubleTyID:
206     return ConstantFP::get(Ty->getContext(),
207                            APFloat::getZero(APFloat::IEEEdouble));
208   case Type::X86_FP80TyID:
209     return ConstantFP::get(Ty->getContext(),
210                            APFloat::getZero(APFloat::x87DoubleExtended));
211   case Type::FP128TyID:
212     return ConstantFP::get(Ty->getContext(),
213                            APFloat::getZero(APFloat::IEEEquad));
214   case Type::PPC_FP128TyID:
215     return ConstantFP::get(Ty->getContext(),
216                            APFloat(APFloat::PPCDoubleDouble,
217                                    APInt::getNullValue(128)));
218   case Type::PointerTyID:
219     return ConstantPointerNull::get(cast<PointerType>(Ty));
220   case Type::StructTyID:
221   case Type::ArrayTyID:
222   case Type::VectorTyID:
223     return ConstantAggregateZero::get(Ty);
224   case Type::TokenTyID:
225     return ConstantTokenNone::get(Ty->getContext());
226   default:
227     // Function, Label, or Opaque type?
228     llvm_unreachable("Cannot create a null constant of that type!");
229   }
230 }
231 
getIntegerValue(Type * Ty,const APInt & V)232 Constant *Constant::getIntegerValue(Type *Ty, const APInt &V) {
233   Type *ScalarTy = Ty->getScalarType();
234 
235   // Create the base integer constant.
236   Constant *C = ConstantInt::get(Ty->getContext(), V);
237 
238   // Convert an integer to a pointer, if necessary.
239   if (PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
240     C = ConstantExpr::getIntToPtr(C, PTy);
241 
242   // Broadcast a scalar to a vector, if necessary.
243   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
244     C = ConstantVector::getSplat(VTy->getNumElements(), C);
245 
246   return C;
247 }
248 
getAllOnesValue(Type * Ty)249 Constant *Constant::getAllOnesValue(Type *Ty) {
250   if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
251     return ConstantInt::get(Ty->getContext(),
252                             APInt::getAllOnesValue(ITy->getBitWidth()));
253 
254   if (Ty->isFloatingPointTy()) {
255     APFloat FL = APFloat::getAllOnesValue(Ty->getPrimitiveSizeInBits(),
256                                           !Ty->isPPC_FP128Ty());
257     return ConstantFP::get(Ty->getContext(), FL);
258   }
259 
260   VectorType *VTy = cast<VectorType>(Ty);
261   return ConstantVector::getSplat(VTy->getNumElements(),
262                                   getAllOnesValue(VTy->getElementType()));
263 }
264 
getAggregateElement(unsigned Elt) const265 Constant *Constant::getAggregateElement(unsigned Elt) const {
266   if (const ConstantAggregate *CC = dyn_cast<ConstantAggregate>(this))
267     return Elt < CC->getNumOperands() ? CC->getOperand(Elt) : nullptr;
268 
269   if (const ConstantAggregateZero *CAZ = dyn_cast<ConstantAggregateZero>(this))
270     return Elt < CAZ->getNumElements() ? CAZ->getElementValue(Elt) : nullptr;
271 
272   if (const UndefValue *UV = dyn_cast<UndefValue>(this))
273     return Elt < UV->getNumElements() ? UV->getElementValue(Elt) : nullptr;
274 
275   if (const ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(this))
276     return Elt < CDS->getNumElements() ? CDS->getElementAsConstant(Elt)
277                                        : nullptr;
278   return nullptr;
279 }
280 
getAggregateElement(Constant * Elt) const281 Constant *Constant::getAggregateElement(Constant *Elt) const {
282   assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer");
283   if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt))
284     return getAggregateElement(CI->getZExtValue());
285   return nullptr;
286 }
287 
destroyConstant()288 void Constant::destroyConstant() {
289   /// First call destroyConstantImpl on the subclass.  This gives the subclass
290   /// a chance to remove the constant from any maps/pools it's contained in.
291   switch (getValueID()) {
292   default:
293     llvm_unreachable("Not a constant!");
294 #define HANDLE_CONSTANT(Name)                                                  \
295   case Value::Name##Val:                                                       \
296     cast<Name>(this)->destroyConstantImpl();                                   \
297     break;
298 #include "llvm/IR/Value.def"
299   }
300 
301   // When a Constant is destroyed, there may be lingering
302   // references to the constant by other constants in the constant pool.  These
303   // constants are implicitly dependent on the module that is being deleted,
304   // but they don't know that.  Because we only find out when the CPV is
305   // deleted, we must now notify all of our users (that should only be
306   // Constants) that they are, in fact, invalid now and should be deleted.
307   //
308   while (!use_empty()) {
309     Value *V = user_back();
310 #ifndef NDEBUG // Only in -g mode...
311     if (!isa<Constant>(V)) {
312       dbgs() << "While deleting: " << *this
313              << "\n\nUse still stuck around after Def is destroyed: " << *V
314              << "\n\n";
315     }
316 #endif
317     assert(isa<Constant>(V) && "References remain to Constant being destroyed");
318     cast<Constant>(V)->destroyConstant();
319 
320     // The constant should remove itself from our use list...
321     assert((use_empty() || user_back() != V) && "Constant not removed!");
322   }
323 
324   // Value has no outstanding references it is safe to delete it now...
325   delete this;
326 }
327 
canTrapImpl(const Constant * C,SmallPtrSetImpl<const ConstantExpr * > & NonTrappingOps)328 static bool canTrapImpl(const Constant *C,
329                         SmallPtrSetImpl<const ConstantExpr *> &NonTrappingOps) {
330   assert(C->getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
331   // The only thing that could possibly trap are constant exprs.
332   const ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
333   if (!CE)
334     return false;
335 
336   // ConstantExpr traps if any operands can trap.
337   for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) {
338     if (ConstantExpr *Op = dyn_cast<ConstantExpr>(CE->getOperand(i))) {
339       if (NonTrappingOps.insert(Op).second && canTrapImpl(Op, NonTrappingOps))
340         return true;
341     }
342   }
343 
344   // Otherwise, only specific operations can trap.
345   switch (CE->getOpcode()) {
346   default:
347     return false;
348   case Instruction::UDiv:
349   case Instruction::SDiv:
350   case Instruction::FDiv:
351   case Instruction::URem:
352   case Instruction::SRem:
353   case Instruction::FRem:
354     // Div and rem can trap if the RHS is not known to be non-zero.
355     if (!isa<ConstantInt>(CE->getOperand(1)) ||CE->getOperand(1)->isNullValue())
356       return true;
357     return false;
358   }
359 }
360 
canTrap() const361 bool Constant::canTrap() const {
362   SmallPtrSet<const ConstantExpr *, 4> NonTrappingOps;
363   return canTrapImpl(this, NonTrappingOps);
364 }
365 
366 /// Check if C contains a GlobalValue for which Predicate is true.
367 static bool
ConstHasGlobalValuePredicate(const Constant * C,bool (* Predicate)(const GlobalValue *))368 ConstHasGlobalValuePredicate(const Constant *C,
369                              bool (*Predicate)(const GlobalValue *)) {
370   SmallPtrSet<const Constant *, 8> Visited;
371   SmallVector<const Constant *, 8> WorkList;
372   WorkList.push_back(C);
373   Visited.insert(C);
374 
375   while (!WorkList.empty()) {
376     const Constant *WorkItem = WorkList.pop_back_val();
377     if (const auto *GV = dyn_cast<GlobalValue>(WorkItem))
378       if (Predicate(GV))
379         return true;
380     for (const Value *Op : WorkItem->operands()) {
381       const Constant *ConstOp = dyn_cast<Constant>(Op);
382       if (!ConstOp)
383         continue;
384       if (Visited.insert(ConstOp).second)
385         WorkList.push_back(ConstOp);
386     }
387   }
388   return false;
389 }
390 
isThreadDependent() const391 bool Constant::isThreadDependent() const {
392   auto DLLImportPredicate = [](const GlobalValue *GV) {
393     return GV->isThreadLocal();
394   };
395   return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
396 }
397 
isDLLImportDependent() const398 bool Constant::isDLLImportDependent() const {
399   auto DLLImportPredicate = [](const GlobalValue *GV) {
400     return GV->hasDLLImportStorageClass();
401   };
402   return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
403 }
404 
isConstantUsed() const405 bool Constant::isConstantUsed() const {
406   for (const User *U : users()) {
407     const Constant *UC = dyn_cast<Constant>(U);
408     if (!UC || isa<GlobalValue>(UC))
409       return true;
410 
411     if (UC->isConstantUsed())
412       return true;
413   }
414   return false;
415 }
416 
needsRelocation() const417 bool Constant::needsRelocation() const {
418   if (isa<GlobalValue>(this))
419     return true; // Global reference.
420 
421   if (const BlockAddress *BA = dyn_cast<BlockAddress>(this))
422     return BA->getFunction()->needsRelocation();
423 
424   // While raw uses of blockaddress need to be relocated, differences between
425   // two of them don't when they are for labels in the same function.  This is a
426   // common idiom when creating a table for the indirect goto extension, so we
427   // handle it efficiently here.
428   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(this))
429     if (CE->getOpcode() == Instruction::Sub) {
430       ConstantExpr *LHS = dyn_cast<ConstantExpr>(CE->getOperand(0));
431       ConstantExpr *RHS = dyn_cast<ConstantExpr>(CE->getOperand(1));
432       if (LHS && RHS && LHS->getOpcode() == Instruction::PtrToInt &&
433           RHS->getOpcode() == Instruction::PtrToInt &&
434           isa<BlockAddress>(LHS->getOperand(0)) &&
435           isa<BlockAddress>(RHS->getOperand(0)) &&
436           cast<BlockAddress>(LHS->getOperand(0))->getFunction() ==
437               cast<BlockAddress>(RHS->getOperand(0))->getFunction())
438         return false;
439     }
440 
441   bool Result = false;
442   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
443     Result |= cast<Constant>(getOperand(i))->needsRelocation();
444 
445   return Result;
446 }
447 
448 /// If the specified constantexpr is dead, remove it. This involves recursively
449 /// eliminating any dead users of the constantexpr.
removeDeadUsersOfConstant(const Constant * C)450 static bool removeDeadUsersOfConstant(const Constant *C) {
451   if (isa<GlobalValue>(C)) return false; // Cannot remove this
452 
453   while (!C->use_empty()) {
454     const Constant *User = dyn_cast<Constant>(C->user_back());
455     if (!User) return false; // Non-constant usage;
456     if (!removeDeadUsersOfConstant(User))
457       return false; // Constant wasn't dead
458   }
459 
460   const_cast<Constant*>(C)->destroyConstant();
461   return true;
462 }
463 
464 
removeDeadConstantUsers() const465 void Constant::removeDeadConstantUsers() const {
466   Value::const_user_iterator I = user_begin(), E = user_end();
467   Value::const_user_iterator LastNonDeadUser = E;
468   while (I != E) {
469     const Constant *User = dyn_cast<Constant>(*I);
470     if (!User) {
471       LastNonDeadUser = I;
472       ++I;
473       continue;
474     }
475 
476     if (!removeDeadUsersOfConstant(User)) {
477       // If the constant wasn't dead, remember that this was the last live use
478       // and move on to the next constant.
479       LastNonDeadUser = I;
480       ++I;
481       continue;
482     }
483 
484     // If the constant was dead, then the iterator is invalidated.
485     if (LastNonDeadUser == E) {
486       I = user_begin();
487       if (I == E) break;
488     } else {
489       I = LastNonDeadUser;
490       ++I;
491     }
492   }
493 }
494 
495 
496 
497 //===----------------------------------------------------------------------===//
498 //                                ConstantInt
499 //===----------------------------------------------------------------------===//
500 
anchor()501 void ConstantInt::anchor() { }
502 
ConstantInt(IntegerType * Ty,const APInt & V)503 ConstantInt::ConstantInt(IntegerType *Ty, const APInt &V)
504     : ConstantData(Ty, ConstantIntVal), Val(V) {
505   assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type");
506 }
507 
getTrue(LLVMContext & Context)508 ConstantInt *ConstantInt::getTrue(LLVMContext &Context) {
509   LLVMContextImpl *pImpl = Context.pImpl;
510   if (!pImpl->TheTrueVal)
511     pImpl->TheTrueVal = ConstantInt::get(Type::getInt1Ty(Context), 1);
512   return pImpl->TheTrueVal;
513 }
514 
getFalse(LLVMContext & Context)515 ConstantInt *ConstantInt::getFalse(LLVMContext &Context) {
516   LLVMContextImpl *pImpl = Context.pImpl;
517   if (!pImpl->TheFalseVal)
518     pImpl->TheFalseVal = ConstantInt::get(Type::getInt1Ty(Context), 0);
519   return pImpl->TheFalseVal;
520 }
521 
getTrue(Type * Ty)522 Constant *ConstantInt::getTrue(Type *Ty) {
523   VectorType *VTy = dyn_cast<VectorType>(Ty);
524   if (!VTy) {
525     assert(Ty->isIntegerTy(1) && "True must be i1 or vector of i1.");
526     return ConstantInt::getTrue(Ty->getContext());
527   }
528   assert(VTy->getElementType()->isIntegerTy(1) &&
529          "True must be vector of i1 or i1.");
530   return ConstantVector::getSplat(VTy->getNumElements(),
531                                   ConstantInt::getTrue(Ty->getContext()));
532 }
533 
getFalse(Type * Ty)534 Constant *ConstantInt::getFalse(Type *Ty) {
535   VectorType *VTy = dyn_cast<VectorType>(Ty);
536   if (!VTy) {
537     assert(Ty->isIntegerTy(1) && "False must be i1 or vector of i1.");
538     return ConstantInt::getFalse(Ty->getContext());
539   }
540   assert(VTy->getElementType()->isIntegerTy(1) &&
541          "False must be vector of i1 or i1.");
542   return ConstantVector::getSplat(VTy->getNumElements(),
543                                   ConstantInt::getFalse(Ty->getContext()));
544 }
545 
546 // Get a ConstantInt from an APInt.
get(LLVMContext & Context,const APInt & V)547 ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) {
548   // get an existing value or the insertion position
549   LLVMContextImpl *pImpl = Context.pImpl;
550   ConstantInt *&Slot = pImpl->IntConstants[V];
551   if (!Slot) {
552     // Get the corresponding integer type for the bit width of the value.
553     IntegerType *ITy = IntegerType::get(Context, V.getBitWidth());
554     Slot = new ConstantInt(ITy, V);
555   }
556   assert(Slot->getType() == IntegerType::get(Context, V.getBitWidth()));
557   return Slot;
558 }
559 
get(Type * Ty,uint64_t V,bool isSigned)560 Constant *ConstantInt::get(Type *Ty, uint64_t V, bool isSigned) {
561   Constant *C = get(cast<IntegerType>(Ty->getScalarType()), V, isSigned);
562 
563   // For vectors, broadcast the value.
564   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
565     return ConstantVector::getSplat(VTy->getNumElements(), C);
566 
567   return C;
568 }
569 
get(IntegerType * Ty,uint64_t V,bool isSigned)570 ConstantInt *ConstantInt::get(IntegerType *Ty, uint64_t V, bool isSigned) {
571   return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
572 }
573 
getSigned(IntegerType * Ty,int64_t V)574 ConstantInt *ConstantInt::getSigned(IntegerType *Ty, int64_t V) {
575   return get(Ty, V, true);
576 }
577 
getSigned(Type * Ty,int64_t V)578 Constant *ConstantInt::getSigned(Type *Ty, int64_t V) {
579   return get(Ty, V, true);
580 }
581 
get(Type * Ty,const APInt & V)582 Constant *ConstantInt::get(Type *Ty, const APInt& V) {
583   ConstantInt *C = get(Ty->getContext(), V);
584   assert(C->getType() == Ty->getScalarType() &&
585          "ConstantInt type doesn't match the type implied by its value!");
586 
587   // For vectors, broadcast the value.
588   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
589     return ConstantVector::getSplat(VTy->getNumElements(), C);
590 
591   return C;
592 }
593 
get(IntegerType * Ty,StringRef Str,uint8_t radix)594 ConstantInt *ConstantInt::get(IntegerType* Ty, StringRef Str, uint8_t radix) {
595   return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix));
596 }
597 
598 /// Remove the constant from the constant table.
destroyConstantImpl()599 void ConstantInt::destroyConstantImpl() {
600   llvm_unreachable("You can't ConstantInt->destroyConstantImpl()!");
601 }
602 
603 //===----------------------------------------------------------------------===//
604 //                                ConstantFP
605 //===----------------------------------------------------------------------===//
606 
TypeToFloatSemantics(Type * Ty)607 static const fltSemantics *TypeToFloatSemantics(Type *Ty) {
608   if (Ty->isHalfTy())
609     return &APFloat::IEEEhalf;
610   if (Ty->isFloatTy())
611     return &APFloat::IEEEsingle;
612   if (Ty->isDoubleTy())
613     return &APFloat::IEEEdouble;
614   if (Ty->isX86_FP80Ty())
615     return &APFloat::x87DoubleExtended;
616   else if (Ty->isFP128Ty())
617     return &APFloat::IEEEquad;
618 
619   assert(Ty->isPPC_FP128Ty() && "Unknown FP format");
620   return &APFloat::PPCDoubleDouble;
621 }
622 
anchor()623 void ConstantFP::anchor() { }
624 
get(Type * Ty,double V)625 Constant *ConstantFP::get(Type *Ty, double V) {
626   LLVMContext &Context = Ty->getContext();
627 
628   APFloat FV(V);
629   bool ignored;
630   FV.convert(*TypeToFloatSemantics(Ty->getScalarType()),
631              APFloat::rmNearestTiesToEven, &ignored);
632   Constant *C = get(Context, FV);
633 
634   // For vectors, broadcast the value.
635   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
636     return ConstantVector::getSplat(VTy->getNumElements(), C);
637 
638   return C;
639 }
640 
641 
get(Type * Ty,StringRef Str)642 Constant *ConstantFP::get(Type *Ty, StringRef Str) {
643   LLVMContext &Context = Ty->getContext();
644 
645   APFloat FV(*TypeToFloatSemantics(Ty->getScalarType()), Str);
646   Constant *C = get(Context, FV);
647 
648   // For vectors, broadcast the value.
649   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
650     return ConstantVector::getSplat(VTy->getNumElements(), C);
651 
652   return C;
653 }
654 
getNaN(Type * Ty,bool Negative,unsigned Type)655 Constant *ConstantFP::getNaN(Type *Ty, bool Negative, unsigned Type) {
656   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
657   APFloat NaN = APFloat::getNaN(Semantics, Negative, Type);
658   Constant *C = get(Ty->getContext(), NaN);
659 
660   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
661     return ConstantVector::getSplat(VTy->getNumElements(), C);
662 
663   return C;
664 }
665 
getNegativeZero(Type * Ty)666 Constant *ConstantFP::getNegativeZero(Type *Ty) {
667   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
668   APFloat NegZero = APFloat::getZero(Semantics, /*Negative=*/true);
669   Constant *C = get(Ty->getContext(), NegZero);
670 
671   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
672     return ConstantVector::getSplat(VTy->getNumElements(), C);
673 
674   return C;
675 }
676 
677 
getZeroValueForNegation(Type * Ty)678 Constant *ConstantFP::getZeroValueForNegation(Type *Ty) {
679   if (Ty->isFPOrFPVectorTy())
680     return getNegativeZero(Ty);
681 
682   return Constant::getNullValue(Ty);
683 }
684 
685 
686 // ConstantFP accessors.
get(LLVMContext & Context,const APFloat & V)687 ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
688   LLVMContextImpl* pImpl = Context.pImpl;
689 
690   ConstantFP *&Slot = pImpl->FPConstants[V];
691 
692   if (!Slot) {
693     Type *Ty;
694     if (&V.getSemantics() == &APFloat::IEEEhalf)
695       Ty = Type::getHalfTy(Context);
696     else if (&V.getSemantics() == &APFloat::IEEEsingle)
697       Ty = Type::getFloatTy(Context);
698     else if (&V.getSemantics() == &APFloat::IEEEdouble)
699       Ty = Type::getDoubleTy(Context);
700     else if (&V.getSemantics() == &APFloat::x87DoubleExtended)
701       Ty = Type::getX86_FP80Ty(Context);
702     else if (&V.getSemantics() == &APFloat::IEEEquad)
703       Ty = Type::getFP128Ty(Context);
704     else {
705       assert(&V.getSemantics() == &APFloat::PPCDoubleDouble &&
706              "Unknown FP format");
707       Ty = Type::getPPC_FP128Ty(Context);
708     }
709     Slot = new ConstantFP(Ty, V);
710   }
711 
712   return Slot;
713 }
714 
getInfinity(Type * Ty,bool Negative)715 Constant *ConstantFP::getInfinity(Type *Ty, bool Negative) {
716   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty->getScalarType());
717   Constant *C = get(Ty->getContext(), APFloat::getInf(Semantics, Negative));
718 
719   if (VectorType *VTy = dyn_cast<VectorType>(Ty))
720     return ConstantVector::getSplat(VTy->getNumElements(), C);
721 
722   return C;
723 }
724 
ConstantFP(Type * Ty,const APFloat & V)725 ConstantFP::ConstantFP(Type *Ty, const APFloat &V)
726     : ConstantData(Ty, ConstantFPVal), Val(V) {
727   assert(&V.getSemantics() == TypeToFloatSemantics(Ty) &&
728          "FP type Mismatch");
729 }
730 
isExactlyValue(const APFloat & V) const731 bool ConstantFP::isExactlyValue(const APFloat &V) const {
732   return Val.bitwiseIsEqual(V);
733 }
734 
735 /// Remove the constant from the constant table.
destroyConstantImpl()736 void ConstantFP::destroyConstantImpl() {
737   llvm_unreachable("You can't ConstantInt->destroyConstantImpl()!");
738 }
739 
740 //===----------------------------------------------------------------------===//
741 //                   ConstantAggregateZero Implementation
742 //===----------------------------------------------------------------------===//
743 
getSequentialElement() const744 Constant *ConstantAggregateZero::getSequentialElement() const {
745   return Constant::getNullValue(getType()->getSequentialElementType());
746 }
747 
getStructElement(unsigned Elt) const748 Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const {
749   return Constant::getNullValue(getType()->getStructElementType(Elt));
750 }
751 
getElementValue(Constant * C) const752 Constant *ConstantAggregateZero::getElementValue(Constant *C) const {
753   if (isa<SequentialType>(getType()))
754     return getSequentialElement();
755   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
756 }
757 
getElementValue(unsigned Idx) const758 Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const {
759   if (isa<SequentialType>(getType()))
760     return getSequentialElement();
761   return getStructElement(Idx);
762 }
763 
getNumElements() const764 unsigned ConstantAggregateZero::getNumElements() const {
765   Type *Ty = getType();
766   if (auto *AT = dyn_cast<ArrayType>(Ty))
767     return AT->getNumElements();
768   if (auto *VT = dyn_cast<VectorType>(Ty))
769     return VT->getNumElements();
770   return Ty->getStructNumElements();
771 }
772 
773 //===----------------------------------------------------------------------===//
774 //                         UndefValue Implementation
775 //===----------------------------------------------------------------------===//
776 
getSequentialElement() const777 UndefValue *UndefValue::getSequentialElement() const {
778   return UndefValue::get(getType()->getSequentialElementType());
779 }
780 
getStructElement(unsigned Elt) const781 UndefValue *UndefValue::getStructElement(unsigned Elt) const {
782   return UndefValue::get(getType()->getStructElementType(Elt));
783 }
784 
getElementValue(Constant * C) const785 UndefValue *UndefValue::getElementValue(Constant *C) const {
786   if (isa<SequentialType>(getType()))
787     return getSequentialElement();
788   return getStructElement(cast<ConstantInt>(C)->getZExtValue());
789 }
790 
getElementValue(unsigned Idx) const791 UndefValue *UndefValue::getElementValue(unsigned Idx) const {
792   if (isa<SequentialType>(getType()))
793     return getSequentialElement();
794   return getStructElement(Idx);
795 }
796 
getNumElements() const797 unsigned UndefValue::getNumElements() const {
798   Type *Ty = getType();
799   if (auto *AT = dyn_cast<ArrayType>(Ty))
800     return AT->getNumElements();
801   if (auto *VT = dyn_cast<VectorType>(Ty))
802     return VT->getNumElements();
803   return Ty->getStructNumElements();
804 }
805 
806 //===----------------------------------------------------------------------===//
807 //                            ConstantXXX Classes
808 //===----------------------------------------------------------------------===//
809 
810 template <typename ItTy, typename EltTy>
rangeOnlyContains(ItTy Start,ItTy End,EltTy Elt)811 static bool rangeOnlyContains(ItTy Start, ItTy End, EltTy Elt) {
812   for (; Start != End; ++Start)
813     if (*Start != Elt)
814       return false;
815   return true;
816 }
817 
818 template <typename SequentialTy, typename ElementTy>
getIntSequenceIfElementsMatch(ArrayRef<Constant * > V)819 static Constant *getIntSequenceIfElementsMatch(ArrayRef<Constant *> V) {
820   assert(!V.empty() && "Cannot get empty int sequence.");
821 
822   SmallVector<ElementTy, 16> Elts;
823   for (Constant *C : V)
824     if (auto *CI = dyn_cast<ConstantInt>(C))
825       Elts.push_back(CI->getZExtValue());
826     else
827       return nullptr;
828   return SequentialTy::get(V[0]->getContext(), Elts);
829 }
830 
831 template <typename SequentialTy, typename ElementTy>
getFPSequenceIfElementsMatch(ArrayRef<Constant * > V)832 static Constant *getFPSequenceIfElementsMatch(ArrayRef<Constant *> V) {
833   assert(!V.empty() && "Cannot get empty FP sequence.");
834 
835   SmallVector<ElementTy, 16> Elts;
836   for (Constant *C : V)
837     if (auto *CFP = dyn_cast<ConstantFP>(C))
838       Elts.push_back(CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
839     else
840       return nullptr;
841   return SequentialTy::getFP(V[0]->getContext(), Elts);
842 }
843 
844 template <typename SequenceTy>
getSequenceIfElementsMatch(Constant * C,ArrayRef<Constant * > V)845 static Constant *getSequenceIfElementsMatch(Constant *C,
846                                             ArrayRef<Constant *> V) {
847   // We speculatively build the elements here even if it turns out that there is
848   // a constantexpr or something else weird, since it is so uncommon for that to
849   // happen.
850   if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
851     if (CI->getType()->isIntegerTy(8))
852       return getIntSequenceIfElementsMatch<SequenceTy, uint8_t>(V);
853     else if (CI->getType()->isIntegerTy(16))
854       return getIntSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
855     else if (CI->getType()->isIntegerTy(32))
856       return getIntSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
857     else if (CI->getType()->isIntegerTy(64))
858       return getIntSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
859   } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
860     if (CFP->getType()->isHalfTy())
861       return getFPSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
862     else if (CFP->getType()->isFloatTy())
863       return getFPSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
864     else if (CFP->getType()->isDoubleTy())
865       return getFPSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
866   }
867 
868   return nullptr;
869 }
870 
ConstantAggregate(CompositeType * T,ValueTy VT,ArrayRef<Constant * > V)871 ConstantAggregate::ConstantAggregate(CompositeType *T, ValueTy VT,
872                                      ArrayRef<Constant *> V)
873     : Constant(T, VT, OperandTraits<ConstantAggregate>::op_end(this) - V.size(),
874                V.size()) {
875   std::copy(V.begin(), V.end(), op_begin());
876 
877   // Check that types match, unless this is an opaque struct.
878   if (auto *ST = dyn_cast<StructType>(T))
879     if (ST->isOpaque())
880       return;
881   for (unsigned I = 0, E = V.size(); I != E; ++I)
882     assert(V[I]->getType() == T->getTypeAtIndex(I) &&
883            "Initializer for composite element doesn't match!");
884 }
885 
ConstantArray(ArrayType * T,ArrayRef<Constant * > V)886 ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V)
887     : ConstantAggregate(T, ConstantArrayVal, V) {
888   assert(V.size() == T->getNumElements() &&
889          "Invalid initializer for constant array");
890 }
891 
get(ArrayType * Ty,ArrayRef<Constant * > V)892 Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) {
893   if (Constant *C = getImpl(Ty, V))
894     return C;
895   return Ty->getContext().pImpl->ArrayConstants.getOrCreate(Ty, V);
896 }
897 
getImpl(ArrayType * Ty,ArrayRef<Constant * > V)898 Constant *ConstantArray::getImpl(ArrayType *Ty, ArrayRef<Constant*> V) {
899   // Empty arrays are canonicalized to ConstantAggregateZero.
900   if (V.empty())
901     return ConstantAggregateZero::get(Ty);
902 
903   for (unsigned i = 0, e = V.size(); i != e; ++i) {
904     assert(V[i]->getType() == Ty->getElementType() &&
905            "Wrong type in array element initializer");
906   }
907 
908   // If this is an all-zero array, return a ConstantAggregateZero object.  If
909   // all undef, return an UndefValue, if "all simple", then return a
910   // ConstantDataArray.
911   Constant *C = V[0];
912   if (isa<UndefValue>(C) && rangeOnlyContains(V.begin(), V.end(), C))
913     return UndefValue::get(Ty);
914 
915   if (C->isNullValue() && rangeOnlyContains(V.begin(), V.end(), C))
916     return ConstantAggregateZero::get(Ty);
917 
918   // Check to see if all of the elements are ConstantFP or ConstantInt and if
919   // the element type is compatible with ConstantDataVector.  If so, use it.
920   if (ConstantDataSequential::isElementTypeCompatible(C->getType()))
921     return getSequenceIfElementsMatch<ConstantDataArray>(C, V);
922 
923   // Otherwise, we really do want to create a ConstantArray.
924   return nullptr;
925 }
926 
getTypeForElements(LLVMContext & Context,ArrayRef<Constant * > V,bool Packed)927 StructType *ConstantStruct::getTypeForElements(LLVMContext &Context,
928                                                ArrayRef<Constant*> V,
929                                                bool Packed) {
930   unsigned VecSize = V.size();
931   SmallVector<Type*, 16> EltTypes(VecSize);
932   for (unsigned i = 0; i != VecSize; ++i)
933     EltTypes[i] = V[i]->getType();
934 
935   return StructType::get(Context, EltTypes, Packed);
936 }
937 
938 
getTypeForElements(ArrayRef<Constant * > V,bool Packed)939 StructType *ConstantStruct::getTypeForElements(ArrayRef<Constant*> V,
940                                                bool Packed) {
941   assert(!V.empty() &&
942          "ConstantStruct::getTypeForElements cannot be called on empty list");
943   return getTypeForElements(V[0]->getContext(), V, Packed);
944 }
945 
ConstantStruct(StructType * T,ArrayRef<Constant * > V)946 ConstantStruct::ConstantStruct(StructType *T, ArrayRef<Constant *> V)
947     : ConstantAggregate(T, ConstantStructVal, V) {
948   assert((T->isOpaque() || V.size() == T->getNumElements()) &&
949          "Invalid initializer for constant struct");
950 }
951 
952 // ConstantStruct accessors.
get(StructType * ST,ArrayRef<Constant * > V)953 Constant *ConstantStruct::get(StructType *ST, ArrayRef<Constant*> V) {
954   assert((ST->isOpaque() || ST->getNumElements() == V.size()) &&
955          "Incorrect # elements specified to ConstantStruct::get");
956 
957   // Create a ConstantAggregateZero value if all elements are zeros.
958   bool isZero = true;
959   bool isUndef = false;
960 
961   if (!V.empty()) {
962     isUndef = isa<UndefValue>(V[0]);
963     isZero = V[0]->isNullValue();
964     if (isUndef || isZero) {
965       for (unsigned i = 0, e = V.size(); i != e; ++i) {
966         if (!V[i]->isNullValue())
967           isZero = false;
968         if (!isa<UndefValue>(V[i]))
969           isUndef = false;
970       }
971     }
972   }
973   if (isZero)
974     return ConstantAggregateZero::get(ST);
975   if (isUndef)
976     return UndefValue::get(ST);
977 
978   return ST->getContext().pImpl->StructConstants.getOrCreate(ST, V);
979 }
980 
get(StructType * T,...)981 Constant *ConstantStruct::get(StructType *T, ...) {
982   va_list ap;
983   SmallVector<Constant*, 8> Values;
984   va_start(ap, T);
985   while (Constant *Val = va_arg(ap, llvm::Constant*))
986     Values.push_back(Val);
987   va_end(ap);
988   return get(T, Values);
989 }
990 
ConstantVector(VectorType * T,ArrayRef<Constant * > V)991 ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V)
992     : ConstantAggregate(T, ConstantVectorVal, V) {
993   assert(V.size() == T->getNumElements() &&
994          "Invalid initializer for constant vector");
995 }
996 
997 // ConstantVector accessors.
get(ArrayRef<Constant * > V)998 Constant *ConstantVector::get(ArrayRef<Constant*> V) {
999   if (Constant *C = getImpl(V))
1000     return C;
1001   VectorType *Ty = VectorType::get(V.front()->getType(), V.size());
1002   return Ty->getContext().pImpl->VectorConstants.getOrCreate(Ty, V);
1003 }
1004 
getImpl(ArrayRef<Constant * > V)1005 Constant *ConstantVector::getImpl(ArrayRef<Constant*> V) {
1006   assert(!V.empty() && "Vectors can't be empty");
1007   VectorType *T = VectorType::get(V.front()->getType(), V.size());
1008 
1009   // If this is an all-undef or all-zero vector, return a
1010   // ConstantAggregateZero or UndefValue.
1011   Constant *C = V[0];
1012   bool isZero = C->isNullValue();
1013   bool isUndef = isa<UndefValue>(C);
1014 
1015   if (isZero || isUndef) {
1016     for (unsigned i = 1, e = V.size(); i != e; ++i)
1017       if (V[i] != C) {
1018         isZero = isUndef = false;
1019         break;
1020       }
1021   }
1022 
1023   if (isZero)
1024     return ConstantAggregateZero::get(T);
1025   if (isUndef)
1026     return UndefValue::get(T);
1027 
1028   // Check to see if all of the elements are ConstantFP or ConstantInt and if
1029   // the element type is compatible with ConstantDataVector.  If so, use it.
1030   if (ConstantDataSequential::isElementTypeCompatible(C->getType()))
1031     return getSequenceIfElementsMatch<ConstantDataVector>(C, V);
1032 
1033   // Otherwise, the element type isn't compatible with ConstantDataVector, or
1034   // the operand list constants a ConstantExpr or something else strange.
1035   return nullptr;
1036 }
1037 
getSplat(unsigned NumElts,Constant * V)1038 Constant *ConstantVector::getSplat(unsigned NumElts, Constant *V) {
1039   // If this splat is compatible with ConstantDataVector, use it instead of
1040   // ConstantVector.
1041   if ((isa<ConstantFP>(V) || isa<ConstantInt>(V)) &&
1042       ConstantDataSequential::isElementTypeCompatible(V->getType()))
1043     return ConstantDataVector::getSplat(NumElts, V);
1044 
1045   SmallVector<Constant*, 32> Elts(NumElts, V);
1046   return get(Elts);
1047 }
1048 
get(LLVMContext & Context)1049 ConstantTokenNone *ConstantTokenNone::get(LLVMContext &Context) {
1050   LLVMContextImpl *pImpl = Context.pImpl;
1051   if (!pImpl->TheNoneToken)
1052     pImpl->TheNoneToken.reset(new ConstantTokenNone(Context));
1053   return pImpl->TheNoneToken.get();
1054 }
1055 
1056 /// Remove the constant from the constant table.
destroyConstantImpl()1057 void ConstantTokenNone::destroyConstantImpl() {
1058   llvm_unreachable("You can't ConstantTokenNone->destroyConstantImpl()!");
1059 }
1060 
1061 // Utility function for determining if a ConstantExpr is a CastOp or not. This
1062 // can't be inline because we don't want to #include Instruction.h into
1063 // Constant.h
isCast() const1064 bool ConstantExpr::isCast() const {
1065   return Instruction::isCast(getOpcode());
1066 }
1067 
isCompare() const1068 bool ConstantExpr::isCompare() const {
1069   return getOpcode() == Instruction::ICmp || getOpcode() == Instruction::FCmp;
1070 }
1071 
isGEPWithNoNotionalOverIndexing() const1072 bool ConstantExpr::isGEPWithNoNotionalOverIndexing() const {
1073   if (getOpcode() != Instruction::GetElementPtr) return false;
1074 
1075   gep_type_iterator GEPI = gep_type_begin(this), E = gep_type_end(this);
1076   User::const_op_iterator OI = std::next(this->op_begin());
1077 
1078   // Skip the first index, as it has no static limit.
1079   ++GEPI;
1080   ++OI;
1081 
1082   // The remaining indices must be compile-time known integers within the
1083   // bounds of the corresponding notional static array types.
1084   for (; GEPI != E; ++GEPI, ++OI) {
1085     ConstantInt *CI = dyn_cast<ConstantInt>(*OI);
1086     if (!CI) return false;
1087     if (ArrayType *ATy = dyn_cast<ArrayType>(*GEPI))
1088       if (CI->getValue().getActiveBits() > 64 ||
1089           CI->getZExtValue() >= ATy->getNumElements())
1090         return false;
1091   }
1092 
1093   // All the indices checked out.
1094   return true;
1095 }
1096 
hasIndices() const1097 bool ConstantExpr::hasIndices() const {
1098   return getOpcode() == Instruction::ExtractValue ||
1099          getOpcode() == Instruction::InsertValue;
1100 }
1101 
getIndices() const1102 ArrayRef<unsigned> ConstantExpr::getIndices() const {
1103   if (const ExtractValueConstantExpr *EVCE =
1104         dyn_cast<ExtractValueConstantExpr>(this))
1105     return EVCE->Indices;
1106 
1107   return cast<InsertValueConstantExpr>(this)->Indices;
1108 }
1109 
getPredicate() const1110 unsigned ConstantExpr::getPredicate() const {
1111   return cast<CompareConstantExpr>(this)->predicate;
1112 }
1113 
1114 Constant *
getWithOperandReplaced(unsigned OpNo,Constant * Op) const1115 ConstantExpr::getWithOperandReplaced(unsigned OpNo, Constant *Op) const {
1116   assert(Op->getType() == getOperand(OpNo)->getType() &&
1117          "Replacing operand with value of different type!");
1118   if (getOperand(OpNo) == Op)
1119     return const_cast<ConstantExpr*>(this);
1120 
1121   SmallVector<Constant*, 8> NewOps;
1122   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
1123     NewOps.push_back(i == OpNo ? Op : getOperand(i));
1124 
1125   return getWithOperands(NewOps);
1126 }
1127 
getWithOperands(ArrayRef<Constant * > Ops,Type * Ty,bool OnlyIfReduced,Type * SrcTy) const1128 Constant *ConstantExpr::getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1129                                         bool OnlyIfReduced, Type *SrcTy) const {
1130   assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
1131 
1132   // If no operands changed return self.
1133   if (Ty == getType() && std::equal(Ops.begin(), Ops.end(), op_begin()))
1134     return const_cast<ConstantExpr*>(this);
1135 
1136   Type *OnlyIfReducedTy = OnlyIfReduced ? Ty : nullptr;
1137   switch (getOpcode()) {
1138   case Instruction::Trunc:
1139   case Instruction::ZExt:
1140   case Instruction::SExt:
1141   case Instruction::FPTrunc:
1142   case Instruction::FPExt:
1143   case Instruction::UIToFP:
1144   case Instruction::SIToFP:
1145   case Instruction::FPToUI:
1146   case Instruction::FPToSI:
1147   case Instruction::PtrToInt:
1148   case Instruction::IntToPtr:
1149   case Instruction::BitCast:
1150   case Instruction::AddrSpaceCast:
1151     return ConstantExpr::getCast(getOpcode(), Ops[0], Ty, OnlyIfReduced);
1152   case Instruction::Select:
1153     return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2], OnlyIfReducedTy);
1154   case Instruction::InsertElement:
1155     return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2],
1156                                           OnlyIfReducedTy);
1157   case Instruction::ExtractElement:
1158     return ConstantExpr::getExtractElement(Ops[0], Ops[1], OnlyIfReducedTy);
1159   case Instruction::InsertValue:
1160     return ConstantExpr::getInsertValue(Ops[0], Ops[1], getIndices(),
1161                                         OnlyIfReducedTy);
1162   case Instruction::ExtractValue:
1163     return ConstantExpr::getExtractValue(Ops[0], getIndices(), OnlyIfReducedTy);
1164   case Instruction::ShuffleVector:
1165     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2],
1166                                           OnlyIfReducedTy);
1167   case Instruction::GetElementPtr: {
1168     auto *GEPO = cast<GEPOperator>(this);
1169     assert(SrcTy || (Ops[0]->getType() == getOperand(0)->getType()));
1170     return ConstantExpr::getGetElementPtr(
1171         SrcTy ? SrcTy : GEPO->getSourceElementType(), Ops[0], Ops.slice(1),
1172         GEPO->isInBounds(), OnlyIfReducedTy);
1173   }
1174   case Instruction::ICmp:
1175   case Instruction::FCmp:
1176     return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1],
1177                                     OnlyIfReducedTy);
1178   default:
1179     assert(getNumOperands() == 2 && "Must be binary operator?");
1180     return ConstantExpr::get(getOpcode(), Ops[0], Ops[1], SubclassOptionalData,
1181                              OnlyIfReducedTy);
1182   }
1183 }
1184 
1185 
1186 //===----------------------------------------------------------------------===//
1187 //                      isValueValidForType implementations
1188 
isValueValidForType(Type * Ty,uint64_t Val)1189 bool ConstantInt::isValueValidForType(Type *Ty, uint64_t Val) {
1190   unsigned NumBits = Ty->getIntegerBitWidth(); // assert okay
1191   if (Ty->isIntegerTy(1))
1192     return Val == 0 || Val == 1;
1193   if (NumBits >= 64)
1194     return true; // always true, has to fit in largest type
1195   uint64_t Max = (1ll << NumBits) - 1;
1196   return Val <= Max;
1197 }
1198 
isValueValidForType(Type * Ty,int64_t Val)1199 bool ConstantInt::isValueValidForType(Type *Ty, int64_t Val) {
1200   unsigned NumBits = Ty->getIntegerBitWidth();
1201   if (Ty->isIntegerTy(1))
1202     return Val == 0 || Val == 1 || Val == -1;
1203   if (NumBits >= 64)
1204     return true; // always true, has to fit in largest type
1205   int64_t Min = -(1ll << (NumBits-1));
1206   int64_t Max = (1ll << (NumBits-1)) - 1;
1207   return (Val >= Min && Val <= Max);
1208 }
1209 
isValueValidForType(Type * Ty,const APFloat & Val)1210 bool ConstantFP::isValueValidForType(Type *Ty, const APFloat& Val) {
1211   // convert modifies in place, so make a copy.
1212   APFloat Val2 = APFloat(Val);
1213   bool losesInfo;
1214   switch (Ty->getTypeID()) {
1215   default:
1216     return false;         // These can't be represented as floating point!
1217 
1218   // FIXME rounding mode needs to be more flexible
1219   case Type::HalfTyID: {
1220     if (&Val2.getSemantics() == &APFloat::IEEEhalf)
1221       return true;
1222     Val2.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &losesInfo);
1223     return !losesInfo;
1224   }
1225   case Type::FloatTyID: {
1226     if (&Val2.getSemantics() == &APFloat::IEEEsingle)
1227       return true;
1228     Val2.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &losesInfo);
1229     return !losesInfo;
1230   }
1231   case Type::DoubleTyID: {
1232     if (&Val2.getSemantics() == &APFloat::IEEEhalf ||
1233         &Val2.getSemantics() == &APFloat::IEEEsingle ||
1234         &Val2.getSemantics() == &APFloat::IEEEdouble)
1235       return true;
1236     Val2.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo);
1237     return !losesInfo;
1238   }
1239   case Type::X86_FP80TyID:
1240     return &Val2.getSemantics() == &APFloat::IEEEhalf ||
1241            &Val2.getSemantics() == &APFloat::IEEEsingle ||
1242            &Val2.getSemantics() == &APFloat::IEEEdouble ||
1243            &Val2.getSemantics() == &APFloat::x87DoubleExtended;
1244   case Type::FP128TyID:
1245     return &Val2.getSemantics() == &APFloat::IEEEhalf ||
1246            &Val2.getSemantics() == &APFloat::IEEEsingle ||
1247            &Val2.getSemantics() == &APFloat::IEEEdouble ||
1248            &Val2.getSemantics() == &APFloat::IEEEquad;
1249   case Type::PPC_FP128TyID:
1250     return &Val2.getSemantics() == &APFloat::IEEEhalf ||
1251            &Val2.getSemantics() == &APFloat::IEEEsingle ||
1252            &Val2.getSemantics() == &APFloat::IEEEdouble ||
1253            &Val2.getSemantics() == &APFloat::PPCDoubleDouble;
1254   }
1255 }
1256 
1257 
1258 //===----------------------------------------------------------------------===//
1259 //                      Factory Function Implementation
1260 
get(Type * Ty)1261 ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
1262   assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
1263          "Cannot create an aggregate zero of non-aggregate type!");
1264 
1265   ConstantAggregateZero *&Entry = Ty->getContext().pImpl->CAZConstants[Ty];
1266   if (!Entry)
1267     Entry = new ConstantAggregateZero(Ty);
1268 
1269   return Entry;
1270 }
1271 
1272 /// Remove the constant from the constant table.
destroyConstantImpl()1273 void ConstantAggregateZero::destroyConstantImpl() {
1274   getContext().pImpl->CAZConstants.erase(getType());
1275 }
1276 
1277 /// Remove the constant from the constant table.
destroyConstantImpl()1278 void ConstantArray::destroyConstantImpl() {
1279   getType()->getContext().pImpl->ArrayConstants.remove(this);
1280 }
1281 
1282 
1283 //---- ConstantStruct::get() implementation...
1284 //
1285 
1286 /// Remove the constant from the constant table.
destroyConstantImpl()1287 void ConstantStruct::destroyConstantImpl() {
1288   getType()->getContext().pImpl->StructConstants.remove(this);
1289 }
1290 
1291 /// Remove the constant from the constant table.
destroyConstantImpl()1292 void ConstantVector::destroyConstantImpl() {
1293   getType()->getContext().pImpl->VectorConstants.remove(this);
1294 }
1295 
getSplatValue() const1296 Constant *Constant::getSplatValue() const {
1297   assert(this->getType()->isVectorTy() && "Only valid for vectors!");
1298   if (isa<ConstantAggregateZero>(this))
1299     return getNullValue(this->getType()->getVectorElementType());
1300   if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
1301     return CV->getSplatValue();
1302   if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
1303     return CV->getSplatValue();
1304   return nullptr;
1305 }
1306 
getSplatValue() const1307 Constant *ConstantVector::getSplatValue() const {
1308   // Check out first element.
1309   Constant *Elt = getOperand(0);
1310   // Then make sure all remaining elements point to the same value.
1311   for (unsigned I = 1, E = getNumOperands(); I < E; ++I)
1312     if (getOperand(I) != Elt)
1313       return nullptr;
1314   return Elt;
1315 }
1316 
getUniqueInteger() const1317 const APInt &Constant::getUniqueInteger() const {
1318   if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
1319     return CI->getValue();
1320   assert(this->getSplatValue() && "Doesn't contain a unique integer!");
1321   const Constant *C = this->getAggregateElement(0U);
1322   assert(C && isa<ConstantInt>(C) && "Not a vector of numbers!");
1323   return cast<ConstantInt>(C)->getValue();
1324 }
1325 
1326 //---- ConstantPointerNull::get() implementation.
1327 //
1328 
get(PointerType * Ty)1329 ConstantPointerNull *ConstantPointerNull::get(PointerType *Ty) {
1330   ConstantPointerNull *&Entry = Ty->getContext().pImpl->CPNConstants[Ty];
1331   if (!Entry)
1332     Entry = new ConstantPointerNull(Ty);
1333 
1334   return Entry;
1335 }
1336 
1337 /// Remove the constant from the constant table.
destroyConstantImpl()1338 void ConstantPointerNull::destroyConstantImpl() {
1339   getContext().pImpl->CPNConstants.erase(getType());
1340 }
1341 
get(Type * Ty)1342 UndefValue *UndefValue::get(Type *Ty) {
1343   UndefValue *&Entry = Ty->getContext().pImpl->UVConstants[Ty];
1344   if (!Entry)
1345     Entry = new UndefValue(Ty);
1346 
1347   return Entry;
1348 }
1349 
1350 /// Remove the constant from the constant table.
destroyConstantImpl()1351 void UndefValue::destroyConstantImpl() {
1352   // Free the constant and any dangling references to it.
1353   getContext().pImpl->UVConstants.erase(getType());
1354 }
1355 
get(BasicBlock * BB)1356 BlockAddress *BlockAddress::get(BasicBlock *BB) {
1357   assert(BB->getParent() && "Block must have a parent");
1358   return get(BB->getParent(), BB);
1359 }
1360 
get(Function * F,BasicBlock * BB)1361 BlockAddress *BlockAddress::get(Function *F, BasicBlock *BB) {
1362   BlockAddress *&BA =
1363     F->getContext().pImpl->BlockAddresses[std::make_pair(F, BB)];
1364   if (!BA)
1365     BA = new BlockAddress(F, BB);
1366 
1367   assert(BA->getFunction() == F && "Basic block moved between functions");
1368   return BA;
1369 }
1370 
BlockAddress(Function * F,BasicBlock * BB)1371 BlockAddress::BlockAddress(Function *F, BasicBlock *BB)
1372 : Constant(Type::getInt8PtrTy(F->getContext()), Value::BlockAddressVal,
1373            &Op<0>(), 2) {
1374   setOperand(0, F);
1375   setOperand(1, BB);
1376   BB->AdjustBlockAddressRefCount(1);
1377 }
1378 
lookup(const BasicBlock * BB)1379 BlockAddress *BlockAddress::lookup(const BasicBlock *BB) {
1380   if (!BB->hasAddressTaken())
1381     return nullptr;
1382 
1383   const Function *F = BB->getParent();
1384   assert(F && "Block must have a parent");
1385   BlockAddress *BA =
1386       F->getContext().pImpl->BlockAddresses.lookup(std::make_pair(F, BB));
1387   assert(BA && "Refcount and block address map disagree!");
1388   return BA;
1389 }
1390 
1391 /// Remove the constant from the constant table.
destroyConstantImpl()1392 void BlockAddress::destroyConstantImpl() {
1393   getFunction()->getType()->getContext().pImpl
1394     ->BlockAddresses.erase(std::make_pair(getFunction(), getBasicBlock()));
1395   getBasicBlock()->AdjustBlockAddressRefCount(-1);
1396 }
1397 
handleOperandChangeImpl(Value * From,Value * To)1398 Value *BlockAddress::handleOperandChangeImpl(Value *From, Value *To) {
1399   // This could be replacing either the Basic Block or the Function.  In either
1400   // case, we have to remove the map entry.
1401   Function *NewF = getFunction();
1402   BasicBlock *NewBB = getBasicBlock();
1403 
1404   if (From == NewF)
1405     NewF = cast<Function>(To->stripPointerCasts());
1406   else {
1407     assert(From == NewBB && "From does not match any operand");
1408     NewBB = cast<BasicBlock>(To);
1409   }
1410 
1411   // See if the 'new' entry already exists, if not, just update this in place
1412   // and return early.
1413   BlockAddress *&NewBA =
1414     getContext().pImpl->BlockAddresses[std::make_pair(NewF, NewBB)];
1415   if (NewBA)
1416     return NewBA;
1417 
1418   getBasicBlock()->AdjustBlockAddressRefCount(-1);
1419 
1420   // Remove the old entry, this can't cause the map to rehash (just a
1421   // tombstone will get added).
1422   getContext().pImpl->BlockAddresses.erase(std::make_pair(getFunction(),
1423                                                           getBasicBlock()));
1424   NewBA = this;
1425   setOperand(0, NewF);
1426   setOperand(1, NewBB);
1427   getBasicBlock()->AdjustBlockAddressRefCount(1);
1428 
1429   // If we just want to keep the existing value, then return null.
1430   // Callers know that this means we shouldn't delete this value.
1431   return nullptr;
1432 }
1433 
1434 //---- ConstantExpr::get() implementations.
1435 //
1436 
1437 /// This is a utility function to handle folding of casts and lookup of the
1438 /// cast in the ExprConstants map. It is used by the various get* methods below.
getFoldedCast(Instruction::CastOps opc,Constant * C,Type * Ty,bool OnlyIfReduced=false)1439 static Constant *getFoldedCast(Instruction::CastOps opc, Constant *C, Type *Ty,
1440                                bool OnlyIfReduced = false) {
1441   assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
1442   // Fold a few common cases
1443   if (Constant *FC = ConstantFoldCastInstruction(opc, C, Ty))
1444     return FC;
1445 
1446   if (OnlyIfReduced)
1447     return nullptr;
1448 
1449   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
1450 
1451   // Look up the constant in the table first to ensure uniqueness.
1452   ConstantExprKeyType Key(opc, C);
1453 
1454   return pImpl->ExprConstants.getOrCreate(Ty, Key);
1455 }
1456 
getCast(unsigned oc,Constant * C,Type * Ty,bool OnlyIfReduced)1457 Constant *ConstantExpr::getCast(unsigned oc, Constant *C, Type *Ty,
1458                                 bool OnlyIfReduced) {
1459   Instruction::CastOps opc = Instruction::CastOps(oc);
1460   assert(Instruction::isCast(opc) && "opcode out of range");
1461   assert(C && Ty && "Null arguments to getCast");
1462   assert(CastInst::castIsValid(opc, C, Ty) && "Invalid constantexpr cast!");
1463 
1464   switch (opc) {
1465   default:
1466     llvm_unreachable("Invalid cast opcode");
1467   case Instruction::Trunc:
1468     return getTrunc(C, Ty, OnlyIfReduced);
1469   case Instruction::ZExt:
1470     return getZExt(C, Ty, OnlyIfReduced);
1471   case Instruction::SExt:
1472     return getSExt(C, Ty, OnlyIfReduced);
1473   case Instruction::FPTrunc:
1474     return getFPTrunc(C, Ty, OnlyIfReduced);
1475   case Instruction::FPExt:
1476     return getFPExtend(C, Ty, OnlyIfReduced);
1477   case Instruction::UIToFP:
1478     return getUIToFP(C, Ty, OnlyIfReduced);
1479   case Instruction::SIToFP:
1480     return getSIToFP(C, Ty, OnlyIfReduced);
1481   case Instruction::FPToUI:
1482     return getFPToUI(C, Ty, OnlyIfReduced);
1483   case Instruction::FPToSI:
1484     return getFPToSI(C, Ty, OnlyIfReduced);
1485   case Instruction::PtrToInt:
1486     return getPtrToInt(C, Ty, OnlyIfReduced);
1487   case Instruction::IntToPtr:
1488     return getIntToPtr(C, Ty, OnlyIfReduced);
1489   case Instruction::BitCast:
1490     return getBitCast(C, Ty, OnlyIfReduced);
1491   case Instruction::AddrSpaceCast:
1492     return getAddrSpaceCast(C, Ty, OnlyIfReduced);
1493   }
1494 }
1495 
getZExtOrBitCast(Constant * C,Type * Ty)1496 Constant *ConstantExpr::getZExtOrBitCast(Constant *C, Type *Ty) {
1497   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1498     return getBitCast(C, Ty);
1499   return getZExt(C, Ty);
1500 }
1501 
getSExtOrBitCast(Constant * C,Type * Ty)1502 Constant *ConstantExpr::getSExtOrBitCast(Constant *C, Type *Ty) {
1503   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1504     return getBitCast(C, Ty);
1505   return getSExt(C, Ty);
1506 }
1507 
getTruncOrBitCast(Constant * C,Type * Ty)1508 Constant *ConstantExpr::getTruncOrBitCast(Constant *C, Type *Ty) {
1509   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
1510     return getBitCast(C, Ty);
1511   return getTrunc(C, Ty);
1512 }
1513 
getPointerCast(Constant * S,Type * Ty)1514 Constant *ConstantExpr::getPointerCast(Constant *S, Type *Ty) {
1515   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
1516   assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
1517           "Invalid cast");
1518 
1519   if (Ty->isIntOrIntVectorTy())
1520     return getPtrToInt(S, Ty);
1521 
1522   unsigned SrcAS = S->getType()->getPointerAddressSpace();
1523   if (Ty->isPtrOrPtrVectorTy() && SrcAS != Ty->getPointerAddressSpace())
1524     return getAddrSpaceCast(S, Ty);
1525 
1526   return getBitCast(S, Ty);
1527 }
1528 
getPointerBitCastOrAddrSpaceCast(Constant * S,Type * Ty)1529 Constant *ConstantExpr::getPointerBitCastOrAddrSpaceCast(Constant *S,
1530                                                          Type *Ty) {
1531   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
1532   assert(Ty->isPtrOrPtrVectorTy() && "Invalid cast");
1533 
1534   if (S->getType()->getPointerAddressSpace() != Ty->getPointerAddressSpace())
1535     return getAddrSpaceCast(S, Ty);
1536 
1537   return getBitCast(S, Ty);
1538 }
1539 
getIntegerCast(Constant * C,Type * Ty,bool isSigned)1540 Constant *ConstantExpr::getIntegerCast(Constant *C, Type *Ty, bool isSigned) {
1541   assert(C->getType()->isIntOrIntVectorTy() &&
1542          Ty->isIntOrIntVectorTy() && "Invalid cast");
1543   unsigned SrcBits = C->getType()->getScalarSizeInBits();
1544   unsigned DstBits = Ty->getScalarSizeInBits();
1545   Instruction::CastOps opcode =
1546     (SrcBits == DstBits ? Instruction::BitCast :
1547      (SrcBits > DstBits ? Instruction::Trunc :
1548       (isSigned ? Instruction::SExt : Instruction::ZExt)));
1549   return getCast(opcode, C, Ty);
1550 }
1551 
getFPCast(Constant * C,Type * Ty)1552 Constant *ConstantExpr::getFPCast(Constant *C, Type *Ty) {
1553   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
1554          "Invalid cast");
1555   unsigned SrcBits = C->getType()->getScalarSizeInBits();
1556   unsigned DstBits = Ty->getScalarSizeInBits();
1557   if (SrcBits == DstBits)
1558     return C; // Avoid a useless cast
1559   Instruction::CastOps opcode =
1560     (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt);
1561   return getCast(opcode, C, Ty);
1562 }
1563 
getTrunc(Constant * C,Type * Ty,bool OnlyIfReduced)1564 Constant *ConstantExpr::getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced) {
1565 #ifndef NDEBUG
1566   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1567   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1568 #endif
1569   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1570   assert(C->getType()->isIntOrIntVectorTy() && "Trunc operand must be integer");
1571   assert(Ty->isIntOrIntVectorTy() && "Trunc produces only integral");
1572   assert(C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
1573          "SrcTy must be larger than DestTy for Trunc!");
1574 
1575   return getFoldedCast(Instruction::Trunc, C, Ty, OnlyIfReduced);
1576 }
1577 
getSExt(Constant * C,Type * Ty,bool OnlyIfReduced)1578 Constant *ConstantExpr::getSExt(Constant *C, Type *Ty, bool OnlyIfReduced) {
1579 #ifndef NDEBUG
1580   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1581   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1582 #endif
1583   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1584   assert(C->getType()->isIntOrIntVectorTy() && "SExt operand must be integral");
1585   assert(Ty->isIntOrIntVectorTy() && "SExt produces only integer");
1586   assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1587          "SrcTy must be smaller than DestTy for SExt!");
1588 
1589   return getFoldedCast(Instruction::SExt, C, Ty, OnlyIfReduced);
1590 }
1591 
getZExt(Constant * C,Type * Ty,bool OnlyIfReduced)1592 Constant *ConstantExpr::getZExt(Constant *C, Type *Ty, bool OnlyIfReduced) {
1593 #ifndef NDEBUG
1594   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1595   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1596 #endif
1597   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1598   assert(C->getType()->isIntOrIntVectorTy() && "ZEXt operand must be integral");
1599   assert(Ty->isIntOrIntVectorTy() && "ZExt produces only integer");
1600   assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1601          "SrcTy must be smaller than DestTy for ZExt!");
1602 
1603   return getFoldedCast(Instruction::ZExt, C, Ty, OnlyIfReduced);
1604 }
1605 
getFPTrunc(Constant * C,Type * Ty,bool OnlyIfReduced)1606 Constant *ConstantExpr::getFPTrunc(Constant *C, Type *Ty, bool OnlyIfReduced) {
1607 #ifndef NDEBUG
1608   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1609   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1610 #endif
1611   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1612   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
1613          C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
1614          "This is an illegal floating point truncation!");
1615   return getFoldedCast(Instruction::FPTrunc, C, Ty, OnlyIfReduced);
1616 }
1617 
getFPExtend(Constant * C,Type * Ty,bool OnlyIfReduced)1618 Constant *ConstantExpr::getFPExtend(Constant *C, Type *Ty, bool OnlyIfReduced) {
1619 #ifndef NDEBUG
1620   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1621   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1622 #endif
1623   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1624   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
1625          C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
1626          "This is an illegal floating point extension!");
1627   return getFoldedCast(Instruction::FPExt, C, Ty, OnlyIfReduced);
1628 }
1629 
getUIToFP(Constant * C,Type * Ty,bool OnlyIfReduced)1630 Constant *ConstantExpr::getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced) {
1631 #ifndef NDEBUG
1632   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1633   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1634 #endif
1635   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1636   assert(C->getType()->isIntOrIntVectorTy() && Ty->isFPOrFPVectorTy() &&
1637          "This is an illegal uint to floating point cast!");
1638   return getFoldedCast(Instruction::UIToFP, C, Ty, OnlyIfReduced);
1639 }
1640 
getSIToFP(Constant * C,Type * Ty,bool OnlyIfReduced)1641 Constant *ConstantExpr::getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced) {
1642 #ifndef NDEBUG
1643   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1644   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1645 #endif
1646   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1647   assert(C->getType()->isIntOrIntVectorTy() && Ty->isFPOrFPVectorTy() &&
1648          "This is an illegal sint to floating point cast!");
1649   return getFoldedCast(Instruction::SIToFP, C, Ty, OnlyIfReduced);
1650 }
1651 
getFPToUI(Constant * C,Type * Ty,bool OnlyIfReduced)1652 Constant *ConstantExpr::getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced) {
1653 #ifndef NDEBUG
1654   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1655   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1656 #endif
1657   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1658   assert(C->getType()->isFPOrFPVectorTy() && Ty->isIntOrIntVectorTy() &&
1659          "This is an illegal floating point to uint cast!");
1660   return getFoldedCast(Instruction::FPToUI, C, Ty, OnlyIfReduced);
1661 }
1662 
getFPToSI(Constant * C,Type * Ty,bool OnlyIfReduced)1663 Constant *ConstantExpr::getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced) {
1664 #ifndef NDEBUG
1665   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
1666   bool toVec = Ty->getTypeID() == Type::VectorTyID;
1667 #endif
1668   assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
1669   assert(C->getType()->isFPOrFPVectorTy() && Ty->isIntOrIntVectorTy() &&
1670          "This is an illegal floating point to sint cast!");
1671   return getFoldedCast(Instruction::FPToSI, C, Ty, OnlyIfReduced);
1672 }
1673 
getPtrToInt(Constant * C,Type * DstTy,bool OnlyIfReduced)1674 Constant *ConstantExpr::getPtrToInt(Constant *C, Type *DstTy,
1675                                     bool OnlyIfReduced) {
1676   assert(C->getType()->getScalarType()->isPointerTy() &&
1677          "PtrToInt source must be pointer or pointer vector");
1678   assert(DstTy->getScalarType()->isIntegerTy() &&
1679          "PtrToInt destination must be integer or integer vector");
1680   assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
1681   if (isa<VectorType>(C->getType()))
1682     assert(C->getType()->getVectorNumElements()==DstTy->getVectorNumElements()&&
1683            "Invalid cast between a different number of vector elements");
1684   return getFoldedCast(Instruction::PtrToInt, C, DstTy, OnlyIfReduced);
1685 }
1686 
getIntToPtr(Constant * C,Type * DstTy,bool OnlyIfReduced)1687 Constant *ConstantExpr::getIntToPtr(Constant *C, Type *DstTy,
1688                                     bool OnlyIfReduced) {
1689   assert(C->getType()->getScalarType()->isIntegerTy() &&
1690          "IntToPtr source must be integer or integer vector");
1691   assert(DstTy->getScalarType()->isPointerTy() &&
1692          "IntToPtr destination must be a pointer or pointer vector");
1693   assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
1694   if (isa<VectorType>(C->getType()))
1695     assert(C->getType()->getVectorNumElements()==DstTy->getVectorNumElements()&&
1696            "Invalid cast between a different number of vector elements");
1697   return getFoldedCast(Instruction::IntToPtr, C, DstTy, OnlyIfReduced);
1698 }
1699 
getBitCast(Constant * C,Type * DstTy,bool OnlyIfReduced)1700 Constant *ConstantExpr::getBitCast(Constant *C, Type *DstTy,
1701                                    bool OnlyIfReduced) {
1702   assert(CastInst::castIsValid(Instruction::BitCast, C, DstTy) &&
1703          "Invalid constantexpr bitcast!");
1704 
1705   // It is common to ask for a bitcast of a value to its own type, handle this
1706   // speedily.
1707   if (C->getType() == DstTy) return C;
1708 
1709   return getFoldedCast(Instruction::BitCast, C, DstTy, OnlyIfReduced);
1710 }
1711 
getAddrSpaceCast(Constant * C,Type * DstTy,bool OnlyIfReduced)1712 Constant *ConstantExpr::getAddrSpaceCast(Constant *C, Type *DstTy,
1713                                          bool OnlyIfReduced) {
1714   assert(CastInst::castIsValid(Instruction::AddrSpaceCast, C, DstTy) &&
1715          "Invalid constantexpr addrspacecast!");
1716 
1717   // Canonicalize addrspacecasts between different pointer types by first
1718   // bitcasting the pointer type and then converting the address space.
1719   PointerType *SrcScalarTy = cast<PointerType>(C->getType()->getScalarType());
1720   PointerType *DstScalarTy = cast<PointerType>(DstTy->getScalarType());
1721   Type *DstElemTy = DstScalarTy->getElementType();
1722   if (SrcScalarTy->getElementType() != DstElemTy) {
1723     Type *MidTy = PointerType::get(DstElemTy, SrcScalarTy->getAddressSpace());
1724     if (VectorType *VT = dyn_cast<VectorType>(DstTy)) {
1725       // Handle vectors of pointers.
1726       MidTy = VectorType::get(MidTy, VT->getNumElements());
1727     }
1728     C = getBitCast(C, MidTy);
1729   }
1730   return getFoldedCast(Instruction::AddrSpaceCast, C, DstTy, OnlyIfReduced);
1731 }
1732 
get(unsigned Opcode,Constant * C1,Constant * C2,unsigned Flags,Type * OnlyIfReducedTy)1733 Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
1734                             unsigned Flags, Type *OnlyIfReducedTy) {
1735   // Check the operands for consistency first.
1736   assert(Opcode >= Instruction::BinaryOpsBegin &&
1737          Opcode <  Instruction::BinaryOpsEnd   &&
1738          "Invalid opcode in binary constant expression");
1739   assert(C1->getType() == C2->getType() &&
1740          "Operand types in binary constant expression should match");
1741 
1742 #ifndef NDEBUG
1743   switch (Opcode) {
1744   case Instruction::Add:
1745   case Instruction::Sub:
1746   case Instruction::Mul:
1747     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1748     assert(C1->getType()->isIntOrIntVectorTy() &&
1749            "Tried to create an integer operation on a non-integer type!");
1750     break;
1751   case Instruction::FAdd:
1752   case Instruction::FSub:
1753   case Instruction::FMul:
1754     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1755     assert(C1->getType()->isFPOrFPVectorTy() &&
1756            "Tried to create a floating-point operation on a "
1757            "non-floating-point type!");
1758     break;
1759   case Instruction::UDiv:
1760   case Instruction::SDiv:
1761     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1762     assert(C1->getType()->isIntOrIntVectorTy() &&
1763            "Tried to create an arithmetic operation on a non-arithmetic type!");
1764     break;
1765   case Instruction::FDiv:
1766     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1767     assert(C1->getType()->isFPOrFPVectorTy() &&
1768            "Tried to create an arithmetic operation on a non-arithmetic type!");
1769     break;
1770   case Instruction::URem:
1771   case Instruction::SRem:
1772     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1773     assert(C1->getType()->isIntOrIntVectorTy() &&
1774            "Tried to create an arithmetic operation on a non-arithmetic type!");
1775     break;
1776   case Instruction::FRem:
1777     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1778     assert(C1->getType()->isFPOrFPVectorTy() &&
1779            "Tried to create an arithmetic operation on a non-arithmetic type!");
1780     break;
1781   case Instruction::And:
1782   case Instruction::Or:
1783   case Instruction::Xor:
1784     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1785     assert(C1->getType()->isIntOrIntVectorTy() &&
1786            "Tried to create a logical operation on a non-integral type!");
1787     break;
1788   case Instruction::Shl:
1789   case Instruction::LShr:
1790   case Instruction::AShr:
1791     assert(C1->getType() == C2->getType() && "Op types should be identical!");
1792     assert(C1->getType()->isIntOrIntVectorTy() &&
1793            "Tried to create a shift operation on a non-integer type!");
1794     break;
1795   default:
1796     break;
1797   }
1798 #endif
1799 
1800   if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
1801     return FC;          // Fold a few common cases.
1802 
1803   if (OnlyIfReducedTy == C1->getType())
1804     return nullptr;
1805 
1806   Constant *ArgVec[] = { C1, C2 };
1807   ConstantExprKeyType Key(Opcode, ArgVec, 0, Flags);
1808 
1809   LLVMContextImpl *pImpl = C1->getContext().pImpl;
1810   return pImpl->ExprConstants.getOrCreate(C1->getType(), Key);
1811 }
1812 
getSizeOf(Type * Ty)1813 Constant *ConstantExpr::getSizeOf(Type* Ty) {
1814   // sizeof is implemented as: (i64) gep (Ty*)null, 1
1815   // Note that a non-inbounds gep is used, as null isn't within any object.
1816   Constant *GEPIdx = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
1817   Constant *GEP = getGetElementPtr(
1818       Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
1819   return getPtrToInt(GEP,
1820                      Type::getInt64Ty(Ty->getContext()));
1821 }
1822 
getAlignOf(Type * Ty)1823 Constant *ConstantExpr::getAlignOf(Type* Ty) {
1824   // alignof is implemented as: (i64) gep ({i1,Ty}*)null, 0, 1
1825   // Note that a non-inbounds gep is used, as null isn't within any object.
1826   Type *AligningTy =
1827     StructType::get(Type::getInt1Ty(Ty->getContext()), Ty, nullptr);
1828   Constant *NullPtr = Constant::getNullValue(AligningTy->getPointerTo(0));
1829   Constant *Zero = ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0);
1830   Constant *One = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
1831   Constant *Indices[2] = { Zero, One };
1832   Constant *GEP = getGetElementPtr(AligningTy, NullPtr, Indices);
1833   return getPtrToInt(GEP,
1834                      Type::getInt64Ty(Ty->getContext()));
1835 }
1836 
getOffsetOf(StructType * STy,unsigned FieldNo)1837 Constant *ConstantExpr::getOffsetOf(StructType* STy, unsigned FieldNo) {
1838   return getOffsetOf(STy, ConstantInt::get(Type::getInt32Ty(STy->getContext()),
1839                                            FieldNo));
1840 }
1841 
getOffsetOf(Type * Ty,Constant * FieldNo)1842 Constant *ConstantExpr::getOffsetOf(Type* Ty, Constant *FieldNo) {
1843   // offsetof is implemented as: (i64) gep (Ty*)null, 0, FieldNo
1844   // Note that a non-inbounds gep is used, as null isn't within any object.
1845   Constant *GEPIdx[] = {
1846     ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0),
1847     FieldNo
1848   };
1849   Constant *GEP = getGetElementPtr(
1850       Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
1851   return getPtrToInt(GEP,
1852                      Type::getInt64Ty(Ty->getContext()));
1853 }
1854 
getCompare(unsigned short Predicate,Constant * C1,Constant * C2,bool OnlyIfReduced)1855 Constant *ConstantExpr::getCompare(unsigned short Predicate, Constant *C1,
1856                                    Constant *C2, bool OnlyIfReduced) {
1857   assert(C1->getType() == C2->getType() && "Op types should be identical!");
1858 
1859   switch (Predicate) {
1860   default: llvm_unreachable("Invalid CmpInst predicate");
1861   case CmpInst::FCMP_FALSE: case CmpInst::FCMP_OEQ: case CmpInst::FCMP_OGT:
1862   case CmpInst::FCMP_OGE:   case CmpInst::FCMP_OLT: case CmpInst::FCMP_OLE:
1863   case CmpInst::FCMP_ONE:   case CmpInst::FCMP_ORD: case CmpInst::FCMP_UNO:
1864   case CmpInst::FCMP_UEQ:   case CmpInst::FCMP_UGT: case CmpInst::FCMP_UGE:
1865   case CmpInst::FCMP_ULT:   case CmpInst::FCMP_ULE: case CmpInst::FCMP_UNE:
1866   case CmpInst::FCMP_TRUE:
1867     return getFCmp(Predicate, C1, C2, OnlyIfReduced);
1868 
1869   case CmpInst::ICMP_EQ:  case CmpInst::ICMP_NE:  case CmpInst::ICMP_UGT:
1870   case CmpInst::ICMP_UGE: case CmpInst::ICMP_ULT: case CmpInst::ICMP_ULE:
1871   case CmpInst::ICMP_SGT: case CmpInst::ICMP_SGE: case CmpInst::ICMP_SLT:
1872   case CmpInst::ICMP_SLE:
1873     return getICmp(Predicate, C1, C2, OnlyIfReduced);
1874   }
1875 }
1876 
getSelect(Constant * C,Constant * V1,Constant * V2,Type * OnlyIfReducedTy)1877 Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2,
1878                                   Type *OnlyIfReducedTy) {
1879   assert(!SelectInst::areInvalidOperands(C, V1, V2)&&"Invalid select operands");
1880 
1881   if (Constant *SC = ConstantFoldSelectInstruction(C, V1, V2))
1882     return SC;        // Fold common cases
1883 
1884   if (OnlyIfReducedTy == V1->getType())
1885     return nullptr;
1886 
1887   Constant *ArgVec[] = { C, V1, V2 };
1888   ConstantExprKeyType Key(Instruction::Select, ArgVec);
1889 
1890   LLVMContextImpl *pImpl = C->getContext().pImpl;
1891   return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
1892 }
1893 
getGetElementPtr(Type * Ty,Constant * C,ArrayRef<Value * > Idxs,bool InBounds,Type * OnlyIfReducedTy)1894 Constant *ConstantExpr::getGetElementPtr(Type *Ty, Constant *C,
1895                                          ArrayRef<Value *> Idxs, bool InBounds,
1896                                          Type *OnlyIfReducedTy) {
1897   if (!Ty)
1898     Ty = cast<PointerType>(C->getType()->getScalarType())->getElementType();
1899   else
1900     assert(
1901         Ty ==
1902         cast<PointerType>(C->getType()->getScalarType())->getContainedType(0u));
1903 
1904   if (Constant *FC = ConstantFoldGetElementPtr(Ty, C, InBounds, Idxs))
1905     return FC;          // Fold a few common cases.
1906 
1907   // Get the result type of the getelementptr!
1908   Type *DestTy = GetElementPtrInst::getIndexedType(Ty, Idxs);
1909   assert(DestTy && "GEP indices invalid!");
1910   unsigned AS = C->getType()->getPointerAddressSpace();
1911   Type *ReqTy = DestTy->getPointerTo(AS);
1912 
1913   unsigned NumVecElts = 0;
1914   if (C->getType()->isVectorTy())
1915     NumVecElts = C->getType()->getVectorNumElements();
1916   else for (auto Idx : Idxs)
1917     if (Idx->getType()->isVectorTy())
1918       NumVecElts = Idx->getType()->getVectorNumElements();
1919 
1920   if (NumVecElts)
1921     ReqTy = VectorType::get(ReqTy, NumVecElts);
1922 
1923   if (OnlyIfReducedTy == ReqTy)
1924     return nullptr;
1925 
1926   // Look up the constant in the table first to ensure uniqueness
1927   std::vector<Constant*> ArgVec;
1928   ArgVec.reserve(1 + Idxs.size());
1929   ArgVec.push_back(C);
1930   for (unsigned i = 0, e = Idxs.size(); i != e; ++i) {
1931     assert((!Idxs[i]->getType()->isVectorTy() ||
1932             Idxs[i]->getType()->getVectorNumElements() == NumVecElts) &&
1933            "getelementptr index type missmatch");
1934 
1935     Constant *Idx = cast<Constant>(Idxs[i]);
1936     if (NumVecElts && !Idxs[i]->getType()->isVectorTy())
1937       Idx = ConstantVector::getSplat(NumVecElts, Idx);
1938     ArgVec.push_back(Idx);
1939   }
1940   const ConstantExprKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
1941                                 InBounds ? GEPOperator::IsInBounds : 0, None,
1942                                 Ty);
1943 
1944   LLVMContextImpl *pImpl = C->getContext().pImpl;
1945   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
1946 }
1947 
getICmp(unsigned short pred,Constant * LHS,Constant * RHS,bool OnlyIfReduced)1948 Constant *ConstantExpr::getICmp(unsigned short pred, Constant *LHS,
1949                                 Constant *RHS, bool OnlyIfReduced) {
1950   assert(LHS->getType() == RHS->getType());
1951   assert(pred >= ICmpInst::FIRST_ICMP_PREDICATE &&
1952          pred <= ICmpInst::LAST_ICMP_PREDICATE && "Invalid ICmp Predicate");
1953 
1954   if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
1955     return FC;          // Fold a few common cases...
1956 
1957   if (OnlyIfReduced)
1958     return nullptr;
1959 
1960   // Look up the constant in the table first to ensure uniqueness
1961   Constant *ArgVec[] = { LHS, RHS };
1962   // Get the key type with both the opcode and predicate
1963   const ConstantExprKeyType Key(Instruction::ICmp, ArgVec, pred);
1964 
1965   Type *ResultTy = Type::getInt1Ty(LHS->getContext());
1966   if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
1967     ResultTy = VectorType::get(ResultTy, VT->getNumElements());
1968 
1969   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
1970   return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
1971 }
1972 
getFCmp(unsigned short pred,Constant * LHS,Constant * RHS,bool OnlyIfReduced)1973 Constant *ConstantExpr::getFCmp(unsigned short pred, Constant *LHS,
1974                                 Constant *RHS, bool OnlyIfReduced) {
1975   assert(LHS->getType() == RHS->getType());
1976   assert(pred <= FCmpInst::LAST_FCMP_PREDICATE && "Invalid FCmp Predicate");
1977 
1978   if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
1979     return FC;          // Fold a few common cases...
1980 
1981   if (OnlyIfReduced)
1982     return nullptr;
1983 
1984   // Look up the constant in the table first to ensure uniqueness
1985   Constant *ArgVec[] = { LHS, RHS };
1986   // Get the key type with both the opcode and predicate
1987   const ConstantExprKeyType Key(Instruction::FCmp, ArgVec, pred);
1988 
1989   Type *ResultTy = Type::getInt1Ty(LHS->getContext());
1990   if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
1991     ResultTy = VectorType::get(ResultTy, VT->getNumElements());
1992 
1993   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
1994   return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
1995 }
1996 
getExtractElement(Constant * Val,Constant * Idx,Type * OnlyIfReducedTy)1997 Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx,
1998                                           Type *OnlyIfReducedTy) {
1999   assert(Val->getType()->isVectorTy() &&
2000          "Tried to create extractelement operation on non-vector type!");
2001   assert(Idx->getType()->isIntegerTy() &&
2002          "Extractelement index must be an integer type!");
2003 
2004   if (Constant *FC = ConstantFoldExtractElementInstruction(Val, Idx))
2005     return FC;          // Fold a few common cases.
2006 
2007   Type *ReqTy = Val->getType()->getVectorElementType();
2008   if (OnlyIfReducedTy == ReqTy)
2009     return nullptr;
2010 
2011   // Look up the constant in the table first to ensure uniqueness
2012   Constant *ArgVec[] = { Val, Idx };
2013   const ConstantExprKeyType Key(Instruction::ExtractElement, ArgVec);
2014 
2015   LLVMContextImpl *pImpl = Val->getContext().pImpl;
2016   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2017 }
2018 
getInsertElement(Constant * Val,Constant * Elt,Constant * Idx,Type * OnlyIfReducedTy)2019 Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
2020                                          Constant *Idx, Type *OnlyIfReducedTy) {
2021   assert(Val->getType()->isVectorTy() &&
2022          "Tried to create insertelement operation on non-vector type!");
2023   assert(Elt->getType() == Val->getType()->getVectorElementType() &&
2024          "Insertelement types must match!");
2025   assert(Idx->getType()->isIntegerTy() &&
2026          "Insertelement index must be i32 type!");
2027 
2028   if (Constant *FC = ConstantFoldInsertElementInstruction(Val, Elt, Idx))
2029     return FC;          // Fold a few common cases.
2030 
2031   if (OnlyIfReducedTy == Val->getType())
2032     return nullptr;
2033 
2034   // Look up the constant in the table first to ensure uniqueness
2035   Constant *ArgVec[] = { Val, Elt, Idx };
2036   const ConstantExprKeyType Key(Instruction::InsertElement, ArgVec);
2037 
2038   LLVMContextImpl *pImpl = Val->getContext().pImpl;
2039   return pImpl->ExprConstants.getOrCreate(Val->getType(), Key);
2040 }
2041 
getShuffleVector(Constant * V1,Constant * V2,Constant * Mask,Type * OnlyIfReducedTy)2042 Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
2043                                          Constant *Mask, Type *OnlyIfReducedTy) {
2044   assert(ShuffleVectorInst::isValidOperands(V1, V2, Mask) &&
2045          "Invalid shuffle vector constant expr operands!");
2046 
2047   if (Constant *FC = ConstantFoldShuffleVectorInstruction(V1, V2, Mask))
2048     return FC;          // Fold a few common cases.
2049 
2050   unsigned NElts = Mask->getType()->getVectorNumElements();
2051   Type *EltTy = V1->getType()->getVectorElementType();
2052   Type *ShufTy = VectorType::get(EltTy, NElts);
2053 
2054   if (OnlyIfReducedTy == ShufTy)
2055     return nullptr;
2056 
2057   // Look up the constant in the table first to ensure uniqueness
2058   Constant *ArgVec[] = { V1, V2, Mask };
2059   const ConstantExprKeyType Key(Instruction::ShuffleVector, ArgVec);
2060 
2061   LLVMContextImpl *pImpl = ShufTy->getContext().pImpl;
2062   return pImpl->ExprConstants.getOrCreate(ShufTy, Key);
2063 }
2064 
getInsertValue(Constant * Agg,Constant * Val,ArrayRef<unsigned> Idxs,Type * OnlyIfReducedTy)2065 Constant *ConstantExpr::getInsertValue(Constant *Agg, Constant *Val,
2066                                        ArrayRef<unsigned> Idxs,
2067                                        Type *OnlyIfReducedTy) {
2068   assert(Agg->getType()->isFirstClassType() &&
2069          "Non-first-class type for constant insertvalue expression");
2070 
2071   assert(ExtractValueInst::getIndexedType(Agg->getType(),
2072                                           Idxs) == Val->getType() &&
2073          "insertvalue indices invalid!");
2074   Type *ReqTy = Val->getType();
2075 
2076   if (Constant *FC = ConstantFoldInsertValueInstruction(Agg, Val, Idxs))
2077     return FC;
2078 
2079   if (OnlyIfReducedTy == ReqTy)
2080     return nullptr;
2081 
2082   Constant *ArgVec[] = { Agg, Val };
2083   const ConstantExprKeyType Key(Instruction::InsertValue, ArgVec, 0, 0, Idxs);
2084 
2085   LLVMContextImpl *pImpl = Agg->getContext().pImpl;
2086   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2087 }
2088 
getExtractValue(Constant * Agg,ArrayRef<unsigned> Idxs,Type * OnlyIfReducedTy)2089 Constant *ConstantExpr::getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
2090                                         Type *OnlyIfReducedTy) {
2091   assert(Agg->getType()->isFirstClassType() &&
2092          "Tried to create extractelement operation on non-first-class type!");
2093 
2094   Type *ReqTy = ExtractValueInst::getIndexedType(Agg->getType(), Idxs);
2095   (void)ReqTy;
2096   assert(ReqTy && "extractvalue indices invalid!");
2097 
2098   assert(Agg->getType()->isFirstClassType() &&
2099          "Non-first-class type for constant extractvalue expression");
2100   if (Constant *FC = ConstantFoldExtractValueInstruction(Agg, Idxs))
2101     return FC;
2102 
2103   if (OnlyIfReducedTy == ReqTy)
2104     return nullptr;
2105 
2106   Constant *ArgVec[] = { Agg };
2107   const ConstantExprKeyType Key(Instruction::ExtractValue, ArgVec, 0, 0, Idxs);
2108 
2109   LLVMContextImpl *pImpl = Agg->getContext().pImpl;
2110   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
2111 }
2112 
getNeg(Constant * C,bool HasNUW,bool HasNSW)2113 Constant *ConstantExpr::getNeg(Constant *C, bool HasNUW, bool HasNSW) {
2114   assert(C->getType()->isIntOrIntVectorTy() &&
2115          "Cannot NEG a nonintegral value!");
2116   return getSub(ConstantFP::getZeroValueForNegation(C->getType()),
2117                 C, HasNUW, HasNSW);
2118 }
2119 
getFNeg(Constant * C)2120 Constant *ConstantExpr::getFNeg(Constant *C) {
2121   assert(C->getType()->isFPOrFPVectorTy() &&
2122          "Cannot FNEG a non-floating-point value!");
2123   return getFSub(ConstantFP::getZeroValueForNegation(C->getType()), C);
2124 }
2125 
getNot(Constant * C)2126 Constant *ConstantExpr::getNot(Constant *C) {
2127   assert(C->getType()->isIntOrIntVectorTy() &&
2128          "Cannot NOT a nonintegral value!");
2129   return get(Instruction::Xor, C, Constant::getAllOnesValue(C->getType()));
2130 }
2131 
getAdd(Constant * C1,Constant * C2,bool HasNUW,bool HasNSW)2132 Constant *ConstantExpr::getAdd(Constant *C1, Constant *C2,
2133                                bool HasNUW, bool HasNSW) {
2134   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2135                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2136   return get(Instruction::Add, C1, C2, Flags);
2137 }
2138 
getFAdd(Constant * C1,Constant * C2)2139 Constant *ConstantExpr::getFAdd(Constant *C1, Constant *C2) {
2140   return get(Instruction::FAdd, C1, C2);
2141 }
2142 
getSub(Constant * C1,Constant * C2,bool HasNUW,bool HasNSW)2143 Constant *ConstantExpr::getSub(Constant *C1, Constant *C2,
2144                                bool HasNUW, bool HasNSW) {
2145   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2146                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2147   return get(Instruction::Sub, C1, C2, Flags);
2148 }
2149 
getFSub(Constant * C1,Constant * C2)2150 Constant *ConstantExpr::getFSub(Constant *C1, Constant *C2) {
2151   return get(Instruction::FSub, C1, C2);
2152 }
2153 
getMul(Constant * C1,Constant * C2,bool HasNUW,bool HasNSW)2154 Constant *ConstantExpr::getMul(Constant *C1, Constant *C2,
2155                                bool HasNUW, bool HasNSW) {
2156   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2157                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2158   return get(Instruction::Mul, C1, C2, Flags);
2159 }
2160 
getFMul(Constant * C1,Constant * C2)2161 Constant *ConstantExpr::getFMul(Constant *C1, Constant *C2) {
2162   return get(Instruction::FMul, C1, C2);
2163 }
2164 
getUDiv(Constant * C1,Constant * C2,bool isExact)2165 Constant *ConstantExpr::getUDiv(Constant *C1, Constant *C2, bool isExact) {
2166   return get(Instruction::UDiv, C1, C2,
2167              isExact ? PossiblyExactOperator::IsExact : 0);
2168 }
2169 
getSDiv(Constant * C1,Constant * C2,bool isExact)2170 Constant *ConstantExpr::getSDiv(Constant *C1, Constant *C2, bool isExact) {
2171   return get(Instruction::SDiv, C1, C2,
2172              isExact ? PossiblyExactOperator::IsExact : 0);
2173 }
2174 
getFDiv(Constant * C1,Constant * C2)2175 Constant *ConstantExpr::getFDiv(Constant *C1, Constant *C2) {
2176   return get(Instruction::FDiv, C1, C2);
2177 }
2178 
getURem(Constant * C1,Constant * C2)2179 Constant *ConstantExpr::getURem(Constant *C1, Constant *C2) {
2180   return get(Instruction::URem, C1, C2);
2181 }
2182 
getSRem(Constant * C1,Constant * C2)2183 Constant *ConstantExpr::getSRem(Constant *C1, Constant *C2) {
2184   return get(Instruction::SRem, C1, C2);
2185 }
2186 
getFRem(Constant * C1,Constant * C2)2187 Constant *ConstantExpr::getFRem(Constant *C1, Constant *C2) {
2188   return get(Instruction::FRem, C1, C2);
2189 }
2190 
getAnd(Constant * C1,Constant * C2)2191 Constant *ConstantExpr::getAnd(Constant *C1, Constant *C2) {
2192   return get(Instruction::And, C1, C2);
2193 }
2194 
getOr(Constant * C1,Constant * C2)2195 Constant *ConstantExpr::getOr(Constant *C1, Constant *C2) {
2196   return get(Instruction::Or, C1, C2);
2197 }
2198 
getXor(Constant * C1,Constant * C2)2199 Constant *ConstantExpr::getXor(Constant *C1, Constant *C2) {
2200   return get(Instruction::Xor, C1, C2);
2201 }
2202 
getShl(Constant * C1,Constant * C2,bool HasNUW,bool HasNSW)2203 Constant *ConstantExpr::getShl(Constant *C1, Constant *C2,
2204                                bool HasNUW, bool HasNSW) {
2205   unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
2206                    (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
2207   return get(Instruction::Shl, C1, C2, Flags);
2208 }
2209 
getLShr(Constant * C1,Constant * C2,bool isExact)2210 Constant *ConstantExpr::getLShr(Constant *C1, Constant *C2, bool isExact) {
2211   return get(Instruction::LShr, C1, C2,
2212              isExact ? PossiblyExactOperator::IsExact : 0);
2213 }
2214 
getAShr(Constant * C1,Constant * C2,bool isExact)2215 Constant *ConstantExpr::getAShr(Constant *C1, Constant *C2, bool isExact) {
2216   return get(Instruction::AShr, C1, C2,
2217              isExact ? PossiblyExactOperator::IsExact : 0);
2218 }
2219 
getBinOpIdentity(unsigned Opcode,Type * Ty)2220 Constant *ConstantExpr::getBinOpIdentity(unsigned Opcode, Type *Ty) {
2221   switch (Opcode) {
2222   default:
2223     // Doesn't have an identity.
2224     return nullptr;
2225 
2226   case Instruction::Add:
2227   case Instruction::Or:
2228   case Instruction::Xor:
2229     return Constant::getNullValue(Ty);
2230 
2231   case Instruction::Mul:
2232     return ConstantInt::get(Ty, 1);
2233 
2234   case Instruction::And:
2235     return Constant::getAllOnesValue(Ty);
2236   }
2237 }
2238 
getBinOpAbsorber(unsigned Opcode,Type * Ty)2239 Constant *ConstantExpr::getBinOpAbsorber(unsigned Opcode, Type *Ty) {
2240   switch (Opcode) {
2241   default:
2242     // Doesn't have an absorber.
2243     return nullptr;
2244 
2245   case Instruction::Or:
2246     return Constant::getAllOnesValue(Ty);
2247 
2248   case Instruction::And:
2249   case Instruction::Mul:
2250     return Constant::getNullValue(Ty);
2251   }
2252 }
2253 
2254 /// Remove the constant from the constant table.
destroyConstantImpl()2255 void ConstantExpr::destroyConstantImpl() {
2256   getType()->getContext().pImpl->ExprConstants.remove(this);
2257 }
2258 
getOpcodeName() const2259 const char *ConstantExpr::getOpcodeName() const {
2260   return Instruction::getOpcodeName(getOpcode());
2261 }
2262 
GetElementPtrConstantExpr(Type * SrcElementTy,Constant * C,ArrayRef<Constant * > IdxList,Type * DestTy)2263 GetElementPtrConstantExpr::GetElementPtrConstantExpr(
2264     Type *SrcElementTy, Constant *C, ArrayRef<Constant *> IdxList, Type *DestTy)
2265     : ConstantExpr(DestTy, Instruction::GetElementPtr,
2266                    OperandTraits<GetElementPtrConstantExpr>::op_end(this) -
2267                        (IdxList.size() + 1),
2268                    IdxList.size() + 1),
2269       SrcElementTy(SrcElementTy),
2270       ResElementTy(GetElementPtrInst::getIndexedType(SrcElementTy, IdxList)) {
2271   Op<0>() = C;
2272   Use *OperandList = getOperandList();
2273   for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
2274     OperandList[i+1] = IdxList[i];
2275 }
2276 
getSourceElementType() const2277 Type *GetElementPtrConstantExpr::getSourceElementType() const {
2278   return SrcElementTy;
2279 }
2280 
getResultElementType() const2281 Type *GetElementPtrConstantExpr::getResultElementType() const {
2282   return ResElementTy;
2283 }
2284 
2285 //===----------------------------------------------------------------------===//
2286 //                       ConstantData* implementations
2287 
anchor()2288 void ConstantDataArray::anchor() {}
anchor()2289 void ConstantDataVector::anchor() {}
2290 
getElementType() const2291 Type *ConstantDataSequential::getElementType() const {
2292   return getType()->getElementType();
2293 }
2294 
getRawDataValues() const2295 StringRef ConstantDataSequential::getRawDataValues() const {
2296   return StringRef(DataElements, getNumElements()*getElementByteSize());
2297 }
2298 
isElementTypeCompatible(Type * Ty)2299 bool ConstantDataSequential::isElementTypeCompatible(Type *Ty) {
2300   if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) return true;
2301   if (auto *IT = dyn_cast<IntegerType>(Ty)) {
2302     switch (IT->getBitWidth()) {
2303     case 8:
2304     case 16:
2305     case 32:
2306     case 64:
2307       return true;
2308     default: break;
2309     }
2310   }
2311   return false;
2312 }
2313 
getNumElements() const2314 unsigned ConstantDataSequential::getNumElements() const {
2315   if (ArrayType *AT = dyn_cast<ArrayType>(getType()))
2316     return AT->getNumElements();
2317   return getType()->getVectorNumElements();
2318 }
2319 
2320 
getElementByteSize() const2321 uint64_t ConstantDataSequential::getElementByteSize() const {
2322   return getElementType()->getPrimitiveSizeInBits()/8;
2323 }
2324 
2325 /// Return the start of the specified element.
getElementPointer(unsigned Elt) const2326 const char *ConstantDataSequential::getElementPointer(unsigned Elt) const {
2327   assert(Elt < getNumElements() && "Invalid Elt");
2328   return DataElements+Elt*getElementByteSize();
2329 }
2330 
2331 
2332 /// Return true if the array is empty or all zeros.
isAllZeros(StringRef Arr)2333 static bool isAllZeros(StringRef Arr) {
2334   for (char I : Arr)
2335     if (I != 0)
2336       return false;
2337   return true;
2338 }
2339 
2340 /// This is the underlying implementation of all of the
2341 /// ConstantDataSequential::get methods.  They all thunk down to here, providing
2342 /// the correct element type.  We take the bytes in as a StringRef because
2343 /// we *want* an underlying "char*" to avoid TBAA type punning violations.
getImpl(StringRef Elements,Type * Ty)2344 Constant *ConstantDataSequential::getImpl(StringRef Elements, Type *Ty) {
2345   assert(isElementTypeCompatible(Ty->getSequentialElementType()));
2346   // If the elements are all zero or there are no elements, return a CAZ, which
2347   // is more dense and canonical.
2348   if (isAllZeros(Elements))
2349     return ConstantAggregateZero::get(Ty);
2350 
2351   // Do a lookup to see if we have already formed one of these.
2352   auto &Slot =
2353       *Ty->getContext()
2354            .pImpl->CDSConstants.insert(std::make_pair(Elements, nullptr))
2355            .first;
2356 
2357   // The bucket can point to a linked list of different CDS's that have the same
2358   // body but different types.  For example, 0,0,0,1 could be a 4 element array
2359   // of i8, or a 1-element array of i32.  They'll both end up in the same
2360   /// StringMap bucket, linked up by their Next pointers.  Walk the list.
2361   ConstantDataSequential **Entry = &Slot.second;
2362   for (ConstantDataSequential *Node = *Entry; Node;
2363        Entry = &Node->Next, Node = *Entry)
2364     if (Node->getType() == Ty)
2365       return Node;
2366 
2367   // Okay, we didn't get a hit.  Create a node of the right class, link it in,
2368   // and return it.
2369   if (isa<ArrayType>(Ty))
2370     return *Entry = new ConstantDataArray(Ty, Slot.first().data());
2371 
2372   assert(isa<VectorType>(Ty));
2373   return *Entry = new ConstantDataVector(Ty, Slot.first().data());
2374 }
2375 
destroyConstantImpl()2376 void ConstantDataSequential::destroyConstantImpl() {
2377   // Remove the constant from the StringMap.
2378   StringMap<ConstantDataSequential*> &CDSConstants =
2379     getType()->getContext().pImpl->CDSConstants;
2380 
2381   StringMap<ConstantDataSequential*>::iterator Slot =
2382     CDSConstants.find(getRawDataValues());
2383 
2384   assert(Slot != CDSConstants.end() && "CDS not found in uniquing table");
2385 
2386   ConstantDataSequential **Entry = &Slot->getValue();
2387 
2388   // Remove the entry from the hash table.
2389   if (!(*Entry)->Next) {
2390     // If there is only one value in the bucket (common case) it must be this
2391     // entry, and removing the entry should remove the bucket completely.
2392     assert((*Entry) == this && "Hash mismatch in ConstantDataSequential");
2393     getContext().pImpl->CDSConstants.erase(Slot);
2394   } else {
2395     // Otherwise, there are multiple entries linked off the bucket, unlink the
2396     // node we care about but keep the bucket around.
2397     for (ConstantDataSequential *Node = *Entry; ;
2398          Entry = &Node->Next, Node = *Entry) {
2399       assert(Node && "Didn't find entry in its uniquing hash table!");
2400       // If we found our entry, unlink it from the list and we're done.
2401       if (Node == this) {
2402         *Entry = Node->Next;
2403         break;
2404       }
2405     }
2406   }
2407 
2408   // If we were part of a list, make sure that we don't delete the list that is
2409   // still owned by the uniquing map.
2410   Next = nullptr;
2411 }
2412 
2413 /// get() constructors - Return a constant with array type with an element
2414 /// count and element type matching the ArrayRef passed in.  Note that this
2415 /// can return a ConstantAggregateZero object.
get(LLVMContext & Context,ArrayRef<uint8_t> Elts)2416 Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint8_t> Elts) {
2417   Type *Ty = ArrayType::get(Type::getInt8Ty(Context), Elts.size());
2418   const char *Data = reinterpret_cast<const char *>(Elts.data());
2419   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*1), Ty);
2420 }
get(LLVMContext & Context,ArrayRef<uint16_t> Elts)2421 Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
2422   Type *Ty = ArrayType::get(Type::getInt16Ty(Context), Elts.size());
2423   const char *Data = reinterpret_cast<const char *>(Elts.data());
2424   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*2), Ty);
2425 }
get(LLVMContext & Context,ArrayRef<uint32_t> Elts)2426 Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
2427   Type *Ty = ArrayType::get(Type::getInt32Ty(Context), Elts.size());
2428   const char *Data = reinterpret_cast<const char *>(Elts.data());
2429   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
2430 }
get(LLVMContext & Context,ArrayRef<uint64_t> Elts)2431 Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
2432   Type *Ty = ArrayType::get(Type::getInt64Ty(Context), Elts.size());
2433   const char *Data = reinterpret_cast<const char *>(Elts.data());
2434   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*8), Ty);
2435 }
get(LLVMContext & Context,ArrayRef<float> Elts)2436 Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<float> Elts) {
2437   Type *Ty = ArrayType::get(Type::getFloatTy(Context), Elts.size());
2438   const char *Data = reinterpret_cast<const char *>(Elts.data());
2439   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
2440 }
get(LLVMContext & Context,ArrayRef<double> Elts)2441 Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<double> Elts) {
2442   Type *Ty = ArrayType::get(Type::getDoubleTy(Context), Elts.size());
2443   const char *Data = reinterpret_cast<const char *>(Elts.data());
2444   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 8), Ty);
2445 }
2446 
2447 /// getFP() constructors - Return a constant with array type with an element
2448 /// count and element type of float with precision matching the number of
2449 /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
2450 /// double for 64bits) Note that this can return a ConstantAggregateZero
2451 /// object.
getFP(LLVMContext & Context,ArrayRef<uint16_t> Elts)2452 Constant *ConstantDataArray::getFP(LLVMContext &Context,
2453                                    ArrayRef<uint16_t> Elts) {
2454   Type *Ty = ArrayType::get(Type::getHalfTy(Context), Elts.size());
2455   const char *Data = reinterpret_cast<const char *>(Elts.data());
2456   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 2), Ty);
2457 }
getFP(LLVMContext & Context,ArrayRef<uint32_t> Elts)2458 Constant *ConstantDataArray::getFP(LLVMContext &Context,
2459                                    ArrayRef<uint32_t> Elts) {
2460   Type *Ty = ArrayType::get(Type::getFloatTy(Context), Elts.size());
2461   const char *Data = reinterpret_cast<const char *>(Elts.data());
2462   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 4), Ty);
2463 }
getFP(LLVMContext & Context,ArrayRef<uint64_t> Elts)2464 Constant *ConstantDataArray::getFP(LLVMContext &Context,
2465                                    ArrayRef<uint64_t> Elts) {
2466   Type *Ty = ArrayType::get(Type::getDoubleTy(Context), Elts.size());
2467   const char *Data = reinterpret_cast<const char *>(Elts.data());
2468   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 8), Ty);
2469 }
2470 
getString(LLVMContext & Context,StringRef Str,bool AddNull)2471 Constant *ConstantDataArray::getString(LLVMContext &Context,
2472                                        StringRef Str, bool AddNull) {
2473   if (!AddNull) {
2474     const uint8_t *Data = reinterpret_cast<const uint8_t *>(Str.data());
2475     return get(Context, makeArrayRef(const_cast<uint8_t *>(Data),
2476                Str.size()));
2477   }
2478 
2479   SmallVector<uint8_t, 64> ElementVals;
2480   ElementVals.append(Str.begin(), Str.end());
2481   ElementVals.push_back(0);
2482   return get(Context, ElementVals);
2483 }
2484 
2485 /// get() constructors - Return a constant with vector type with an element
2486 /// count and element type matching the ArrayRef passed in.  Note that this
2487 /// can return a ConstantAggregateZero object.
get(LLVMContext & Context,ArrayRef<uint8_t> Elts)2488 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint8_t> Elts){
2489   Type *Ty = VectorType::get(Type::getInt8Ty(Context), Elts.size());
2490   const char *Data = reinterpret_cast<const char *>(Elts.data());
2491   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*1), Ty);
2492 }
get(LLVMContext & Context,ArrayRef<uint16_t> Elts)2493 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
2494   Type *Ty = VectorType::get(Type::getInt16Ty(Context), Elts.size());
2495   const char *Data = reinterpret_cast<const char *>(Elts.data());
2496   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*2), Ty);
2497 }
get(LLVMContext & Context,ArrayRef<uint32_t> Elts)2498 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
2499   Type *Ty = VectorType::get(Type::getInt32Ty(Context), Elts.size());
2500   const char *Data = reinterpret_cast<const char *>(Elts.data());
2501   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
2502 }
get(LLVMContext & Context,ArrayRef<uint64_t> Elts)2503 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
2504   Type *Ty = VectorType::get(Type::getInt64Ty(Context), Elts.size());
2505   const char *Data = reinterpret_cast<const char *>(Elts.data());
2506   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*8), Ty);
2507 }
get(LLVMContext & Context,ArrayRef<float> Elts)2508 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<float> Elts) {
2509   Type *Ty = VectorType::get(Type::getFloatTy(Context), Elts.size());
2510   const char *Data = reinterpret_cast<const char *>(Elts.data());
2511   return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
2512 }
get(LLVMContext & Context,ArrayRef<double> Elts)2513 Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<double> Elts) {
2514   Type *Ty = VectorType::get(Type::getDoubleTy(Context), Elts.size());
2515   const char *Data = reinterpret_cast<const char *>(Elts.data());
2516   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 8), Ty);
2517 }
2518 
2519 /// getFP() constructors - Return a constant with vector type with an element
2520 /// count and element type of float with the precision matching the number of
2521 /// bits in the ArrayRef passed in.  (i.e. half for 16bits, float for 32bits,
2522 /// double for 64bits) Note that this can return a ConstantAggregateZero
2523 /// object.
getFP(LLVMContext & Context,ArrayRef<uint16_t> Elts)2524 Constant *ConstantDataVector::getFP(LLVMContext &Context,
2525                                     ArrayRef<uint16_t> Elts) {
2526   Type *Ty = VectorType::get(Type::getHalfTy(Context), Elts.size());
2527   const char *Data = reinterpret_cast<const char *>(Elts.data());
2528   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 2), Ty);
2529 }
getFP(LLVMContext & Context,ArrayRef<uint32_t> Elts)2530 Constant *ConstantDataVector::getFP(LLVMContext &Context,
2531                                     ArrayRef<uint32_t> Elts) {
2532   Type *Ty = VectorType::get(Type::getFloatTy(Context), Elts.size());
2533   const char *Data = reinterpret_cast<const char *>(Elts.data());
2534   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 4), Ty);
2535 }
getFP(LLVMContext & Context,ArrayRef<uint64_t> Elts)2536 Constant *ConstantDataVector::getFP(LLVMContext &Context,
2537                                     ArrayRef<uint64_t> Elts) {
2538   Type *Ty = VectorType::get(Type::getDoubleTy(Context), Elts.size());
2539   const char *Data = reinterpret_cast<const char *>(Elts.data());
2540   return getImpl(StringRef(const_cast<char *>(Data), Elts.size() * 8), Ty);
2541 }
2542 
getSplat(unsigned NumElts,Constant * V)2543 Constant *ConstantDataVector::getSplat(unsigned NumElts, Constant *V) {
2544   assert(isElementTypeCompatible(V->getType()) &&
2545          "Element type not compatible with ConstantData");
2546   if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
2547     if (CI->getType()->isIntegerTy(8)) {
2548       SmallVector<uint8_t, 16> Elts(NumElts, CI->getZExtValue());
2549       return get(V->getContext(), Elts);
2550     }
2551     if (CI->getType()->isIntegerTy(16)) {
2552       SmallVector<uint16_t, 16> Elts(NumElts, CI->getZExtValue());
2553       return get(V->getContext(), Elts);
2554     }
2555     if (CI->getType()->isIntegerTy(32)) {
2556       SmallVector<uint32_t, 16> Elts(NumElts, CI->getZExtValue());
2557       return get(V->getContext(), Elts);
2558     }
2559     assert(CI->getType()->isIntegerTy(64) && "Unsupported ConstantData type");
2560     SmallVector<uint64_t, 16> Elts(NumElts, CI->getZExtValue());
2561     return get(V->getContext(), Elts);
2562   }
2563 
2564   if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
2565     if (CFP->getType()->isHalfTy()) {
2566       SmallVector<uint16_t, 16> Elts(
2567           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2568       return getFP(V->getContext(), Elts);
2569     }
2570     if (CFP->getType()->isFloatTy()) {
2571       SmallVector<uint32_t, 16> Elts(
2572           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2573       return getFP(V->getContext(), Elts);
2574     }
2575     if (CFP->getType()->isDoubleTy()) {
2576       SmallVector<uint64_t, 16> Elts(
2577           NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
2578       return getFP(V->getContext(), Elts);
2579     }
2580   }
2581   return ConstantVector::getSplat(NumElts, V);
2582 }
2583 
2584 
getElementAsInteger(unsigned Elt) const2585 uint64_t ConstantDataSequential::getElementAsInteger(unsigned Elt) const {
2586   assert(isa<IntegerType>(getElementType()) &&
2587          "Accessor can only be used when element is an integer");
2588   const char *EltPtr = getElementPointer(Elt);
2589 
2590   // The data is stored in host byte order, make sure to cast back to the right
2591   // type to load with the right endianness.
2592   switch (getElementType()->getIntegerBitWidth()) {
2593   default: llvm_unreachable("Invalid bitwidth for CDS");
2594   case 8:
2595     return *const_cast<uint8_t *>(reinterpret_cast<const uint8_t *>(EltPtr));
2596   case 16:
2597     return *const_cast<uint16_t *>(reinterpret_cast<const uint16_t *>(EltPtr));
2598   case 32:
2599     return *const_cast<uint32_t *>(reinterpret_cast<const uint32_t *>(EltPtr));
2600   case 64:
2601     return *const_cast<uint64_t *>(reinterpret_cast<const uint64_t *>(EltPtr));
2602   }
2603 }
2604 
getElementAsAPFloat(unsigned Elt) const2605 APFloat ConstantDataSequential::getElementAsAPFloat(unsigned Elt) const {
2606   const char *EltPtr = getElementPointer(Elt);
2607 
2608   switch (getElementType()->getTypeID()) {
2609   default:
2610     llvm_unreachable("Accessor can only be used when element is float/double!");
2611   case Type::HalfTyID: {
2612     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
2613     return APFloat(APFloat::IEEEhalf, APInt(16, EltVal));
2614   }
2615   case Type::FloatTyID: {
2616     auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
2617     return APFloat(APFloat::IEEEsingle, APInt(32, EltVal));
2618   }
2619   case Type::DoubleTyID: {
2620     auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
2621     return APFloat(APFloat::IEEEdouble, APInt(64, EltVal));
2622   }
2623   }
2624 }
2625 
getElementAsFloat(unsigned Elt) const2626 float ConstantDataSequential::getElementAsFloat(unsigned Elt) const {
2627   assert(getElementType()->isFloatTy() &&
2628          "Accessor can only be used when element is a 'float'");
2629   const float *EltPtr = reinterpret_cast<const float *>(getElementPointer(Elt));
2630   return *const_cast<float *>(EltPtr);
2631 }
2632 
getElementAsDouble(unsigned Elt) const2633 double ConstantDataSequential::getElementAsDouble(unsigned Elt) const {
2634   assert(getElementType()->isDoubleTy() &&
2635          "Accessor can only be used when element is a 'float'");
2636   const double *EltPtr =
2637       reinterpret_cast<const double *>(getElementPointer(Elt));
2638   return *const_cast<double *>(EltPtr);
2639 }
2640 
getElementAsConstant(unsigned Elt) const2641 Constant *ConstantDataSequential::getElementAsConstant(unsigned Elt) const {
2642   if (getElementType()->isHalfTy() || getElementType()->isFloatTy() ||
2643       getElementType()->isDoubleTy())
2644     return ConstantFP::get(getContext(), getElementAsAPFloat(Elt));
2645 
2646   return ConstantInt::get(getElementType(), getElementAsInteger(Elt));
2647 }
2648 
isString() const2649 bool ConstantDataSequential::isString() const {
2650   return isa<ArrayType>(getType()) && getElementType()->isIntegerTy(8);
2651 }
2652 
isCString() const2653 bool ConstantDataSequential::isCString() const {
2654   if (!isString())
2655     return false;
2656 
2657   StringRef Str = getAsString();
2658 
2659   // The last value must be nul.
2660   if (Str.back() != 0) return false;
2661 
2662   // Other elements must be non-nul.
2663   return Str.drop_back().find(0) == StringRef::npos;
2664 }
2665 
getSplatValue() const2666 Constant *ConstantDataVector::getSplatValue() const {
2667   const char *Base = getRawDataValues().data();
2668 
2669   // Compare elements 1+ to the 0'th element.
2670   unsigned EltSize = getElementByteSize();
2671   for (unsigned i = 1, e = getNumElements(); i != e; ++i)
2672     if (memcmp(Base, Base+i*EltSize, EltSize))
2673       return nullptr;
2674 
2675   // If they're all the same, return the 0th one as a representative.
2676   return getElementAsConstant(0);
2677 }
2678 
2679 //===----------------------------------------------------------------------===//
2680 //                handleOperandChange implementations
2681 
2682 /// Update this constant array to change uses of
2683 /// 'From' to be uses of 'To'.  This must update the uniquing data structures
2684 /// etc.
2685 ///
2686 /// Note that we intentionally replace all uses of From with To here.  Consider
2687 /// a large array that uses 'From' 1000 times.  By handling this case all here,
2688 /// ConstantArray::handleOperandChange is only invoked once, and that
2689 /// single invocation handles all 1000 uses.  Handling them one at a time would
2690 /// work, but would be really slow because it would have to unique each updated
2691 /// array instance.
2692 ///
handleOperandChange(Value * From,Value * To)2693 void Constant::handleOperandChange(Value *From, Value *To) {
2694   Value *Replacement = nullptr;
2695   switch (getValueID()) {
2696   default:
2697     llvm_unreachable("Not a constant!");
2698 #define HANDLE_CONSTANT(Name)                                                  \
2699   case Value::Name##Val:                                                       \
2700     Replacement = cast<Name>(this)->handleOperandChangeImpl(From, To);         \
2701     break;
2702 #include "llvm/IR/Value.def"
2703   }
2704 
2705   // If handleOperandChangeImpl returned nullptr, then it handled
2706   // replacing itself and we don't want to delete or replace anything else here.
2707   if (!Replacement)
2708     return;
2709 
2710   // I do need to replace this with an existing value.
2711   assert(Replacement != this && "I didn't contain From!");
2712 
2713   // Everyone using this now uses the replacement.
2714   replaceAllUsesWith(Replacement);
2715 
2716   // Delete the old constant!
2717   destroyConstant();
2718 }
2719 
handleOperandChangeImpl(Value * From,Value * To)2720 Value *ConstantArray::handleOperandChangeImpl(Value *From, Value *To) {
2721   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
2722   Constant *ToC = cast<Constant>(To);
2723 
2724   SmallVector<Constant*, 8> Values;
2725   Values.reserve(getNumOperands());  // Build replacement array.
2726 
2727   // Fill values with the modified operands of the constant array.  Also,
2728   // compute whether this turns into an all-zeros array.
2729   unsigned NumUpdated = 0;
2730 
2731   // Keep track of whether all the values in the array are "ToC".
2732   bool AllSame = true;
2733   Use *OperandList = getOperandList();
2734   unsigned OperandNo = 0;
2735   for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
2736     Constant *Val = cast<Constant>(O->get());
2737     if (Val == From) {
2738       OperandNo = (O - OperandList);
2739       Val = ToC;
2740       ++NumUpdated;
2741     }
2742     Values.push_back(Val);
2743     AllSame &= Val == ToC;
2744   }
2745 
2746   if (AllSame && ToC->isNullValue())
2747     return ConstantAggregateZero::get(getType());
2748 
2749   if (AllSame && isa<UndefValue>(ToC))
2750     return UndefValue::get(getType());
2751 
2752   // Check for any other type of constant-folding.
2753   if (Constant *C = getImpl(getType(), Values))
2754     return C;
2755 
2756   // Update to the new value.
2757   return getContext().pImpl->ArrayConstants.replaceOperandsInPlace(
2758       Values, this, From, ToC, NumUpdated, OperandNo);
2759 }
2760 
handleOperandChangeImpl(Value * From,Value * To)2761 Value *ConstantStruct::handleOperandChangeImpl(Value *From, Value *To) {
2762   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
2763   Constant *ToC = cast<Constant>(To);
2764 
2765   Use *OperandList = getOperandList();
2766 
2767   SmallVector<Constant*, 8> Values;
2768   Values.reserve(getNumOperands());  // Build replacement struct.
2769 
2770   // Fill values with the modified operands of the constant struct.  Also,
2771   // compute whether this turns into an all-zeros struct.
2772   unsigned NumUpdated = 0;
2773   bool AllSame = true;
2774   unsigned OperandNo = 0;
2775   for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O) {
2776     Constant *Val = cast<Constant>(O->get());
2777     if (Val == From) {
2778       OperandNo = (O - OperandList);
2779       Val = ToC;
2780       ++NumUpdated;
2781     }
2782     Values.push_back(Val);
2783     AllSame &= Val == ToC;
2784   }
2785 
2786   if (AllSame && ToC->isNullValue())
2787     return ConstantAggregateZero::get(getType());
2788 
2789   if (AllSame && isa<UndefValue>(ToC))
2790     return UndefValue::get(getType());
2791 
2792   // Update to the new value.
2793   return getContext().pImpl->StructConstants.replaceOperandsInPlace(
2794       Values, this, From, ToC, NumUpdated, OperandNo);
2795 }
2796 
handleOperandChangeImpl(Value * From,Value * To)2797 Value *ConstantVector::handleOperandChangeImpl(Value *From, Value *To) {
2798   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
2799   Constant *ToC = cast<Constant>(To);
2800 
2801   SmallVector<Constant*, 8> Values;
2802   Values.reserve(getNumOperands());  // Build replacement array...
2803   unsigned NumUpdated = 0;
2804   unsigned OperandNo = 0;
2805   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2806     Constant *Val = getOperand(i);
2807     if (Val == From) {
2808       OperandNo = i;
2809       ++NumUpdated;
2810       Val = ToC;
2811     }
2812     Values.push_back(Val);
2813   }
2814 
2815   if (Constant *C = getImpl(Values))
2816     return C;
2817 
2818   // Update to the new value.
2819   return getContext().pImpl->VectorConstants.replaceOperandsInPlace(
2820       Values, this, From, ToC, NumUpdated, OperandNo);
2821 }
2822 
handleOperandChangeImpl(Value * From,Value * ToV)2823 Value *ConstantExpr::handleOperandChangeImpl(Value *From, Value *ToV) {
2824   assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
2825   Constant *To = cast<Constant>(ToV);
2826 
2827   SmallVector<Constant*, 8> NewOps;
2828   unsigned NumUpdated = 0;
2829   unsigned OperandNo = 0;
2830   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2831     Constant *Op = getOperand(i);
2832     if (Op == From) {
2833       OperandNo = i;
2834       ++NumUpdated;
2835       Op = To;
2836     }
2837     NewOps.push_back(Op);
2838   }
2839   assert(NumUpdated && "I didn't contain From!");
2840 
2841   if (Constant *C = getWithOperands(NewOps, getType(), true))
2842     return C;
2843 
2844   // Update to the new value.
2845   return getContext().pImpl->ExprConstants.replaceOperandsInPlace(
2846       NewOps, this, From, To, NumUpdated, OperandNo);
2847 }
2848 
getAsInstruction()2849 Instruction *ConstantExpr::getAsInstruction() {
2850   SmallVector<Value *, 4> ValueOperands(op_begin(), op_end());
2851   ArrayRef<Value*> Ops(ValueOperands);
2852 
2853   switch (getOpcode()) {
2854   case Instruction::Trunc:
2855   case Instruction::ZExt:
2856   case Instruction::SExt:
2857   case Instruction::FPTrunc:
2858   case Instruction::FPExt:
2859   case Instruction::UIToFP:
2860   case Instruction::SIToFP:
2861   case Instruction::FPToUI:
2862   case Instruction::FPToSI:
2863   case Instruction::PtrToInt:
2864   case Instruction::IntToPtr:
2865   case Instruction::BitCast:
2866   case Instruction::AddrSpaceCast:
2867     return CastInst::Create((Instruction::CastOps)getOpcode(),
2868                             Ops[0], getType());
2869   case Instruction::Select:
2870     return SelectInst::Create(Ops[0], Ops[1], Ops[2]);
2871   case Instruction::InsertElement:
2872     return InsertElementInst::Create(Ops[0], Ops[1], Ops[2]);
2873   case Instruction::ExtractElement:
2874     return ExtractElementInst::Create(Ops[0], Ops[1]);
2875   case Instruction::InsertValue:
2876     return InsertValueInst::Create(Ops[0], Ops[1], getIndices());
2877   case Instruction::ExtractValue:
2878     return ExtractValueInst::Create(Ops[0], getIndices());
2879   case Instruction::ShuffleVector:
2880     return new ShuffleVectorInst(Ops[0], Ops[1], Ops[2]);
2881 
2882   case Instruction::GetElementPtr: {
2883     const auto *GO = cast<GEPOperator>(this);
2884     if (GO->isInBounds())
2885       return GetElementPtrInst::CreateInBounds(GO->getSourceElementType(),
2886                                                Ops[0], Ops.slice(1));
2887     return GetElementPtrInst::Create(GO->getSourceElementType(), Ops[0],
2888                                      Ops.slice(1));
2889   }
2890   case Instruction::ICmp:
2891   case Instruction::FCmp:
2892     return CmpInst::Create((Instruction::OtherOps)getOpcode(),
2893                            (CmpInst::Predicate)getPredicate(), Ops[0], Ops[1]);
2894 
2895   default:
2896     assert(getNumOperands() == 2 && "Must be binary operator?");
2897     BinaryOperator *BO =
2898       BinaryOperator::Create((Instruction::BinaryOps)getOpcode(),
2899                              Ops[0], Ops[1]);
2900     if (isa<OverflowingBinaryOperator>(BO)) {
2901       BO->setHasNoUnsignedWrap(SubclassOptionalData &
2902                                OverflowingBinaryOperator::NoUnsignedWrap);
2903       BO->setHasNoSignedWrap(SubclassOptionalData &
2904                              OverflowingBinaryOperator::NoSignedWrap);
2905     }
2906     if (isa<PossiblyExactOperator>(BO))
2907       BO->setIsExact(SubclassOptionalData & PossiblyExactOperator::IsExact);
2908     return BO;
2909   }
2910 }
2911