xref: /llvm-project/llvm/lib/IR/Function.cpp (revision a109dd1398c2b462846bedb928e7cc955daf66a5)
1 //===-- Function.cpp - Implement the Global object classes ----------------===//
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 Function class for the IR library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/IR/Function.h"
15 #include "LLVMContextImpl.h"
16 #include "SymbolTableListTraitsImpl.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/CodeGen/ValueTypes.h"
20 #include "llvm/IR/CallSite.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/DerivedTypes.h"
23 #include "llvm/IR/InstIterator.h"
24 #include "llvm/IR/IntrinsicInst.h"
25 #include "llvm/IR/LLVMContext.h"
26 #include "llvm/IR/MDBuilder.h"
27 #include "llvm/IR/Metadata.h"
28 #include "llvm/IR/Module.h"
29 using namespace llvm;
30 
31 // Explicit instantiations of SymbolTableListTraits since some of the methods
32 // are not in the public header file...
33 template class llvm::SymbolTableListTraits<Argument>;
34 template class llvm::SymbolTableListTraits<BasicBlock>;
35 
36 //===----------------------------------------------------------------------===//
37 // Argument Implementation
38 //===----------------------------------------------------------------------===//
39 
40 void Argument::anchor() { }
41 
42 Argument::Argument(Type *Ty, const Twine &Name, Function *Par)
43   : Value(Ty, Value::ArgumentVal) {
44   Parent = nullptr;
45 
46   if (Par)
47     Par->getArgumentList().push_back(this);
48   setName(Name);
49 }
50 
51 void Argument::setParent(Function *parent) {
52   Parent = parent;
53 }
54 
55 unsigned Argument::getArgNo() const {
56   const Function *F = getParent();
57   assert(F && "Argument is not in a function");
58 
59   Function::const_arg_iterator AI = F->arg_begin();
60   unsigned ArgIdx = 0;
61   for (; &*AI != this; ++AI)
62     ++ArgIdx;
63 
64   return ArgIdx;
65 }
66 
67 bool Argument::hasNonNullAttr() const {
68   if (!getType()->isPointerTy()) return false;
69   if (getParent()->getAttributes().
70         hasAttribute(getArgNo()+1, Attribute::NonNull))
71     return true;
72   else if (getDereferenceableBytes() > 0 &&
73            getType()->getPointerAddressSpace() == 0)
74     return true;
75   return false;
76 }
77 
78 bool Argument::hasByValAttr() const {
79   if (!getType()->isPointerTy()) return false;
80   return hasAttribute(Attribute::ByVal);
81 }
82 
83 bool Argument::hasSwiftSelfAttr() const {
84   return getParent()->getAttributes().
85     hasAttribute(getArgNo()+1, Attribute::SwiftSelf);
86 }
87 
88 bool Argument::hasSwiftErrorAttr() const {
89   return getParent()->getAttributes().
90     hasAttribute(getArgNo()+1, Attribute::SwiftError);
91 }
92 
93 bool Argument::hasInAllocaAttr() const {
94   if (!getType()->isPointerTy()) return false;
95   return hasAttribute(Attribute::InAlloca);
96 }
97 
98 bool Argument::hasByValOrInAllocaAttr() const {
99   if (!getType()->isPointerTy()) return false;
100   AttributeSet Attrs = getParent()->getAttributes();
101   return Attrs.hasAttribute(getArgNo() + 1, Attribute::ByVal) ||
102          Attrs.hasAttribute(getArgNo() + 1, Attribute::InAlloca);
103 }
104 
105 unsigned Argument::getParamAlignment() const {
106   assert(getType()->isPointerTy() && "Only pointers have alignments");
107   return getParent()->getParamAlignment(getArgNo()+1);
108 
109 }
110 
111 uint64_t Argument::getDereferenceableBytes() const {
112   assert(getType()->isPointerTy() &&
113          "Only pointers have dereferenceable bytes");
114   return getParent()->getDereferenceableBytes(getArgNo()+1);
115 }
116 
117 uint64_t Argument::getDereferenceableOrNullBytes() const {
118   assert(getType()->isPointerTy() &&
119          "Only pointers have dereferenceable bytes");
120   return getParent()->getDereferenceableOrNullBytes(getArgNo()+1);
121 }
122 
123 bool Argument::hasNestAttr() const {
124   if (!getType()->isPointerTy()) return false;
125   return hasAttribute(Attribute::Nest);
126 }
127 
128 bool Argument::hasNoAliasAttr() const {
129   if (!getType()->isPointerTy()) return false;
130   return hasAttribute(Attribute::NoAlias);
131 }
132 
133 bool Argument::hasNoCaptureAttr() const {
134   if (!getType()->isPointerTy()) return false;
135   return hasAttribute(Attribute::NoCapture);
136 }
137 
138 bool Argument::hasStructRetAttr() const {
139   if (!getType()->isPointerTy()) return false;
140   return hasAttribute(Attribute::StructRet);
141 }
142 
143 bool Argument::hasReturnedAttr() const {
144   return hasAttribute(Attribute::Returned);
145 }
146 
147 bool Argument::hasZExtAttr() const {
148   return hasAttribute(Attribute::ZExt);
149 }
150 
151 bool Argument::hasSExtAttr() const {
152   return hasAttribute(Attribute::SExt);
153 }
154 
155 bool Argument::onlyReadsMemory() const {
156   return getParent()->getAttributes().
157       hasAttribute(getArgNo()+1, Attribute::ReadOnly) ||
158       getParent()->getAttributes().
159       hasAttribute(getArgNo()+1, Attribute::ReadNone);
160 }
161 
162 void Argument::addAttr(AttributeSet AS) {
163   assert(AS.getNumSlots() <= 1 &&
164          "Trying to add more than one attribute set to an argument!");
165   AttrBuilder B(AS, AS.getSlotIndex(0));
166   getParent()->addAttributes(getArgNo() + 1,
167                              AttributeSet::get(Parent->getContext(),
168                                                getArgNo() + 1, B));
169 }
170 
171 void Argument::removeAttr(AttributeSet AS) {
172   assert(AS.getNumSlots() <= 1 &&
173          "Trying to remove more than one attribute set from an argument!");
174   AttrBuilder B(AS, AS.getSlotIndex(0));
175   getParent()->removeAttributes(getArgNo() + 1,
176                                 AttributeSet::get(Parent->getContext(),
177                                                   getArgNo() + 1, B));
178 }
179 
180 bool Argument::hasAttribute(Attribute::AttrKind Kind) const {
181   return getParent()->hasAttribute(getArgNo() + 1, Kind);
182 }
183 
184 //===----------------------------------------------------------------------===//
185 // Helper Methods in Function
186 //===----------------------------------------------------------------------===//
187 
188 bool Function::isMaterializable() const {
189   return getGlobalObjectSubClassData() & (1 << IsMaterializableBit);
190 }
191 
192 void Function::setIsMaterializable(bool V) {
193   unsigned Mask = 1 << IsMaterializableBit;
194   setGlobalObjectSubClassData((~Mask & getGlobalObjectSubClassData()) |
195                               (V ? Mask : 0u));
196 }
197 
198 LLVMContext &Function::getContext() const {
199   return getType()->getContext();
200 }
201 
202 FunctionType *Function::getFunctionType() const {
203   return cast<FunctionType>(getValueType());
204 }
205 
206 bool Function::isVarArg() const {
207   return getFunctionType()->isVarArg();
208 }
209 
210 Type *Function::getReturnType() const {
211   return getFunctionType()->getReturnType();
212 }
213 
214 void Function::removeFromParent() {
215   getParent()->getFunctionList().remove(getIterator());
216 }
217 
218 void Function::eraseFromParent() {
219   getParent()->getFunctionList().erase(getIterator());
220 }
221 
222 //===----------------------------------------------------------------------===//
223 // Function Implementation
224 //===----------------------------------------------------------------------===//
225 
226 Function::Function(FunctionType *Ty, LinkageTypes Linkage, const Twine &name,
227                    Module *ParentModule)
228     : GlobalObject(Ty, Value::FunctionVal,
229                    OperandTraits<Function>::op_begin(this), 0, Linkage, name) {
230   assert(FunctionType::isValidReturnType(getReturnType()) &&
231          "invalid return type");
232   setGlobalObjectSubClassData(0);
233 
234   // We only need a symbol table for a function if the context keeps value names
235   if (!getContext().shouldDiscardValueNames())
236     SymTab = make_unique<ValueSymbolTable>();
237 
238   // If the function has arguments, mark them as lazily built.
239   if (Ty->getNumParams())
240     setValueSubclassData(1);   // Set the "has lazy arguments" bit.
241 
242   if (ParentModule)
243     ParentModule->getFunctionList().push_back(this);
244 
245   HasLLVMReservedName = getName().startswith("llvm.");
246   // Ensure intrinsics have the right parameter attributes.
247   // Note, the IntID field will have been set in Value::setName if this function
248   // name is a valid intrinsic ID.
249   if (IntID)
250     setAttributes(Intrinsic::getAttributes(getContext(), IntID));
251 }
252 
253 Function::~Function() {
254   dropAllReferences();    // After this it is safe to delete instructions.
255 
256   // Delete all of the method arguments and unlink from symbol table...
257   ArgumentList.clear();
258 
259   // Remove the function from the on-the-side GC table.
260   clearGC();
261 }
262 
263 void Function::BuildLazyArguments() const {
264   // Create the arguments vector, all arguments start out unnamed.
265   FunctionType *FT = getFunctionType();
266   for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
267     assert(!FT->getParamType(i)->isVoidTy() &&
268            "Cannot have void typed arguments!");
269     ArgumentList.push_back(new Argument(FT->getParamType(i)));
270   }
271 
272   // Clear the lazy arguments bit.
273   unsigned SDC = getSubclassDataFromValue();
274   const_cast<Function*>(this)->setValueSubclassData(SDC &= ~(1<<0));
275 }
276 
277 void Function::stealArgumentListFrom(Function &Src) {
278   assert(isDeclaration() && "Expected no references to current arguments");
279 
280   // Drop the current arguments, if any, and set the lazy argument bit.
281   if (!hasLazyArguments()) {
282     assert(llvm::all_of(ArgumentList,
283                         [](const Argument &A) { return A.use_empty(); }) &&
284            "Expected arguments to be unused in declaration");
285     ArgumentList.clear();
286     setValueSubclassData(getSubclassDataFromValue() | (1 << 0));
287   }
288 
289   // Nothing to steal if Src has lazy arguments.
290   if (Src.hasLazyArguments())
291     return;
292 
293   // Steal arguments from Src, and fix the lazy argument bits.
294   ArgumentList.splice(ArgumentList.end(), Src.ArgumentList);
295   setValueSubclassData(getSubclassDataFromValue() & ~(1 << 0));
296   Src.setValueSubclassData(Src.getSubclassDataFromValue() | (1 << 0));
297 }
298 
299 size_t Function::arg_size() const {
300   return getFunctionType()->getNumParams();
301 }
302 bool Function::arg_empty() const {
303   return getFunctionType()->getNumParams() == 0;
304 }
305 
306 // dropAllReferences() - This function causes all the subinstructions to "let
307 // go" of all references that they are maintaining.  This allows one to
308 // 'delete' a whole class at a time, even though there may be circular
309 // references... first all references are dropped, and all use counts go to
310 // zero.  Then everything is deleted for real.  Note that no operations are
311 // valid on an object that has "dropped all references", except operator
312 // delete.
313 //
314 void Function::dropAllReferences() {
315   setIsMaterializable(false);
316 
317   for (BasicBlock &BB : *this)
318     BB.dropAllReferences();
319 
320   // Delete all basic blocks. They are now unused, except possibly by
321   // blockaddresses, but BasicBlock's destructor takes care of those.
322   while (!BasicBlocks.empty())
323     BasicBlocks.begin()->eraseFromParent();
324 
325   // Drop uses of any optional data (real or placeholder).
326   if (getNumOperands()) {
327     User::dropAllReferences();
328     setNumHungOffUseOperands(0);
329     setValueSubclassData(getSubclassDataFromValue() & ~0xe);
330   }
331 
332   // Metadata is stored in a side-table.
333   clearMetadata();
334 }
335 
336 void Function::addAttribute(unsigned i, Attribute::AttrKind Kind) {
337   AttributeSet PAL = getAttributes();
338   PAL = PAL.addAttribute(getContext(), i, Kind);
339   setAttributes(PAL);
340 }
341 
342 void Function::addAttribute(unsigned i, Attribute Attr) {
343   AttributeSet PAL = getAttributes();
344   PAL = PAL.addAttribute(getContext(), i, Attr);
345   setAttributes(PAL);
346 }
347 
348 void Function::addAttributes(unsigned i, AttributeSet Attrs) {
349   AttributeSet PAL = getAttributes();
350   PAL = PAL.addAttributes(getContext(), i, Attrs);
351   setAttributes(PAL);
352 }
353 
354 void Function::removeAttribute(unsigned i, Attribute::AttrKind Kind) {
355   AttributeSet PAL = getAttributes();
356   PAL = PAL.removeAttribute(getContext(), i, Kind);
357   setAttributes(PAL);
358 }
359 
360 void Function::removeAttribute(unsigned i, StringRef Kind) {
361   AttributeSet PAL = getAttributes();
362   PAL = PAL.removeAttribute(getContext(), i, Kind);
363   setAttributes(PAL);
364 }
365 
366 void Function::removeAttributes(unsigned i, AttributeSet Attrs) {
367   AttributeSet PAL = getAttributes();
368   PAL = PAL.removeAttributes(getContext(), i, Attrs);
369   setAttributes(PAL);
370 }
371 
372 void Function::addDereferenceableAttr(unsigned i, uint64_t Bytes) {
373   AttributeSet PAL = getAttributes();
374   PAL = PAL.addDereferenceableAttr(getContext(), i, Bytes);
375   setAttributes(PAL);
376 }
377 
378 void Function::addDereferenceableOrNullAttr(unsigned i, uint64_t Bytes) {
379   AttributeSet PAL = getAttributes();
380   PAL = PAL.addDereferenceableOrNullAttr(getContext(), i, Bytes);
381   setAttributes(PAL);
382 }
383 
384 const std::string &Function::getGC() const {
385   assert(hasGC() && "Function has no collector");
386   return getContext().getGC(*this);
387 }
388 
389 void Function::setGC(std::string Str) {
390   setValueSubclassDataBit(14, !Str.empty());
391   getContext().setGC(*this, std::move(Str));
392 }
393 
394 void Function::clearGC() {
395   if (!hasGC())
396     return;
397   getContext().deleteGC(*this);
398   setValueSubclassDataBit(14, false);
399 }
400 
401 /// Copy all additional attributes (those not needed to create a Function) from
402 /// the Function Src to this one.
403 void Function::copyAttributesFrom(const GlobalValue *Src) {
404   GlobalObject::copyAttributesFrom(Src);
405   const Function *SrcF = dyn_cast<Function>(Src);
406   if (!SrcF)
407     return;
408 
409   setCallingConv(SrcF->getCallingConv());
410   setAttributes(SrcF->getAttributes());
411   if (SrcF->hasGC())
412     setGC(SrcF->getGC());
413   else
414     clearGC();
415   if (SrcF->hasPersonalityFn())
416     setPersonalityFn(SrcF->getPersonalityFn());
417   if (SrcF->hasPrefixData())
418     setPrefixData(SrcF->getPrefixData());
419   if (SrcF->hasPrologueData())
420     setPrologueData(SrcF->getPrologueData());
421 }
422 
423 /// Table of string intrinsic names indexed by enum value.
424 static const char * const IntrinsicNameTable[] = {
425   "not_intrinsic",
426 #define GET_INTRINSIC_NAME_TABLE
427 #include "llvm/IR/Intrinsics.gen"
428 #undef GET_INTRINSIC_NAME_TABLE
429 };
430 
431 /// Table of per-target intrinsic name tables.
432 #define GET_INTRINSIC_TARGET_DATA
433 #include "llvm/IR/Intrinsics.gen"
434 #undef GET_INTRINSIC_TARGET_DATA
435 
436 /// Find the segment of \c IntrinsicNameTable for intrinsics with the same
437 /// target as \c Name, or the generic table if \c Name is not target specific.
438 ///
439 /// Returns the relevant slice of \c IntrinsicNameTable
440 static ArrayRef<const char *> findTargetSubtable(StringRef Name) {
441   assert(Name.startswith("llvm."));
442 
443   ArrayRef<IntrinsicTargetInfo> Targets(TargetInfos);
444   // Drop "llvm." and take the first dotted component. That will be the target
445   // if this is target specific.
446   StringRef Target = Name.drop_front(5).split('.').first;
447   auto It = std::lower_bound(Targets.begin(), Targets.end(), Target,
448                              [](const IntrinsicTargetInfo &TI,
449                                 StringRef Target) { return TI.Name < Target; });
450   // We've either found the target or just fall back to the generic set, which
451   // is always first.
452   const auto &TI = It != Targets.end() && It->Name == Target ? *It : Targets[0];
453   return makeArrayRef(&IntrinsicNameTable[1] + TI.Offset, TI.Count);
454 }
455 
456 /// \brief This does the actual lookup of an intrinsic ID which
457 /// matches the given function name.
458 Intrinsic::ID Function::lookupIntrinsicID(StringRef Name) {
459   ArrayRef<const char *> NameTable = findTargetSubtable(Name);
460   int Idx = Intrinsic::lookupLLVMIntrinsicByName(NameTable, Name);
461   if (Idx == -1)
462     return Intrinsic::not_intrinsic;
463 
464   // Intrinsic IDs correspond to the location in IntrinsicNameTable, but we have
465   // an index into a sub-table.
466   int Adjust = NameTable.data() - IntrinsicNameTable;
467   Intrinsic::ID ID = static_cast<Intrinsic::ID>(Idx + Adjust);
468 
469   // If the intrinsic is not overloaded, require an exact match. If it is
470   // overloaded, require a prefix match.
471   bool IsPrefixMatch = Name.size() > strlen(NameTable[Idx]);
472   return IsPrefixMatch == isOverloaded(ID) ? ID : Intrinsic::not_intrinsic;
473 }
474 
475 void Function::recalculateIntrinsicID() {
476   StringRef Name = getName();
477   if (!Name.startswith("llvm.")) {
478     HasLLVMReservedName = false;
479     IntID = Intrinsic::not_intrinsic;
480     return;
481   }
482   HasLLVMReservedName = true;
483   IntID = lookupIntrinsicID(Name);
484 }
485 
486 /// Returns a stable mangling for the type specified for use in the name
487 /// mangling scheme used by 'any' types in intrinsic signatures.  The mangling
488 /// of named types is simply their name.  Manglings for unnamed types consist
489 /// of a prefix ('p' for pointers, 'a' for arrays, 'f_' for functions)
490 /// combined with the mangling of their component types.  A vararg function
491 /// type will have a suffix of 'vararg'.  Since function types can contain
492 /// other function types, we close a function type mangling with suffix 'f'
493 /// which can't be confused with it's prefix.  This ensures we don't have
494 /// collisions between two unrelated function types. Otherwise, you might
495 /// parse ffXX as f(fXX) or f(fX)X.  (X is a placeholder for any other type.)
496 /// Manglings of integers, floats, and vectors ('i', 'f', and 'v' prefix in most
497 /// cases) fall back to the MVT codepath, where they could be mangled to
498 /// 'x86mmx', for example; matching on derived types is not sufficient to mangle
499 /// everything.
500 static std::string getMangledTypeStr(Type* Ty) {
501   std::string Result;
502   if (PointerType* PTyp = dyn_cast<PointerType>(Ty)) {
503     Result += "p" + llvm::utostr(PTyp->getAddressSpace()) +
504       getMangledTypeStr(PTyp->getElementType());
505   } else if (ArrayType* ATyp = dyn_cast<ArrayType>(Ty)) {
506     Result += "a" + llvm::utostr(ATyp->getNumElements()) +
507       getMangledTypeStr(ATyp->getElementType());
508   } else if (StructType* STyp = dyn_cast<StructType>(Ty)) {
509     assert(!STyp->isLiteral() && "TODO: implement literal types");
510     Result += STyp->getName();
511   } else if (FunctionType* FT = dyn_cast<FunctionType>(Ty)) {
512     Result += "f_" + getMangledTypeStr(FT->getReturnType());
513     for (size_t i = 0; i < FT->getNumParams(); i++)
514       Result += getMangledTypeStr(FT->getParamType(i));
515     if (FT->isVarArg())
516       Result += "vararg";
517     // Ensure nested function types are distinguishable.
518     Result += "f";
519   } else if (isa<VectorType>(Ty))
520     Result += "v" + utostr(Ty->getVectorNumElements()) +
521       getMangledTypeStr(Ty->getVectorElementType());
522   else if (Ty)
523     Result += EVT::getEVT(Ty).getEVTString();
524   return Result;
525 }
526 
527 StringRef Intrinsic::getName(ID id) {
528   assert(id < num_intrinsics && "Invalid intrinsic ID!");
529   assert(!isOverloaded(id) &&
530          "This version of getName does not support overloading");
531   return IntrinsicNameTable[id];
532 }
533 
534 std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
535   assert(id < num_intrinsics && "Invalid intrinsic ID!");
536   std::string Result(IntrinsicNameTable[id]);
537   for (Type *Ty : Tys) {
538     Result += "." + getMangledTypeStr(Ty);
539   }
540   return Result;
541 }
542 
543 
544 /// IIT_Info - These are enumerators that describe the entries returned by the
545 /// getIntrinsicInfoTableEntries function.
546 ///
547 /// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter!
548 enum IIT_Info {
549   // Common values should be encoded with 0-15.
550   IIT_Done = 0,
551   IIT_I1   = 1,
552   IIT_I8   = 2,
553   IIT_I16  = 3,
554   IIT_I32  = 4,
555   IIT_I64  = 5,
556   IIT_F16  = 6,
557   IIT_F32  = 7,
558   IIT_F64  = 8,
559   IIT_V2   = 9,
560   IIT_V4   = 10,
561   IIT_V8   = 11,
562   IIT_V16  = 12,
563   IIT_V32  = 13,
564   IIT_PTR  = 14,
565   IIT_ARG  = 15,
566 
567   // Values from 16+ are only encodable with the inefficient encoding.
568   IIT_V64  = 16,
569   IIT_MMX  = 17,
570   IIT_TOKEN = 18,
571   IIT_METADATA = 19,
572   IIT_EMPTYSTRUCT = 20,
573   IIT_STRUCT2 = 21,
574   IIT_STRUCT3 = 22,
575   IIT_STRUCT4 = 23,
576   IIT_STRUCT5 = 24,
577   IIT_EXTEND_ARG = 25,
578   IIT_TRUNC_ARG = 26,
579   IIT_ANYPTR = 27,
580   IIT_V1   = 28,
581   IIT_VARARG = 29,
582   IIT_HALF_VEC_ARG = 30,
583   IIT_SAME_VEC_WIDTH_ARG = 31,
584   IIT_PTR_TO_ARG = 32,
585   IIT_PTR_TO_ELT = 33,
586   IIT_VEC_OF_PTRS_TO_ELT = 34,
587   IIT_I128 = 35,
588   IIT_V512 = 36,
589   IIT_V1024 = 37
590 };
591 
592 
593 static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
594                       SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) {
595   IIT_Info Info = IIT_Info(Infos[NextElt++]);
596   unsigned StructElts = 2;
597   using namespace Intrinsic;
598 
599   switch (Info) {
600   case IIT_Done:
601     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0));
602     return;
603   case IIT_VARARG:
604     OutputTable.push_back(IITDescriptor::get(IITDescriptor::VarArg, 0));
605     return;
606   case IIT_MMX:
607     OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0));
608     return;
609   case IIT_TOKEN:
610     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Token, 0));
611     return;
612   case IIT_METADATA:
613     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0));
614     return;
615   case IIT_F16:
616     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Half, 0));
617     return;
618   case IIT_F32:
619     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0));
620     return;
621   case IIT_F64:
622     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0));
623     return;
624   case IIT_I1:
625     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1));
626     return;
627   case IIT_I8:
628     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8));
629     return;
630   case IIT_I16:
631     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16));
632     return;
633   case IIT_I32:
634     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32));
635     return;
636   case IIT_I64:
637     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64));
638     return;
639   case IIT_I128:
640     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 128));
641     return;
642   case IIT_V1:
643     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 1));
644     DecodeIITType(NextElt, Infos, OutputTable);
645     return;
646   case IIT_V2:
647     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2));
648     DecodeIITType(NextElt, Infos, OutputTable);
649     return;
650   case IIT_V4:
651     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4));
652     DecodeIITType(NextElt, Infos, OutputTable);
653     return;
654   case IIT_V8:
655     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8));
656     DecodeIITType(NextElt, Infos, OutputTable);
657     return;
658   case IIT_V16:
659     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16));
660     DecodeIITType(NextElt, Infos, OutputTable);
661     return;
662   case IIT_V32:
663     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32));
664     DecodeIITType(NextElt, Infos, OutputTable);
665     return;
666   case IIT_V64:
667     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 64));
668     DecodeIITType(NextElt, Infos, OutputTable);
669     return;
670   case IIT_V512:
671     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 512));
672     DecodeIITType(NextElt, Infos, OutputTable);
673     return;
674   case IIT_V1024:
675     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 1024));
676     DecodeIITType(NextElt, Infos, OutputTable);
677     return;
678   case IIT_PTR:
679     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0));
680     DecodeIITType(NextElt, Infos, OutputTable);
681     return;
682   case IIT_ANYPTR: {  // [ANYPTR addrspace, subtype]
683     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer,
684                                              Infos[NextElt++]));
685     DecodeIITType(NextElt, Infos, OutputTable);
686     return;
687   }
688   case IIT_ARG: {
689     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
690     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo));
691     return;
692   }
693   case IIT_EXTEND_ARG: {
694     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
695     OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendArgument,
696                                              ArgInfo));
697     return;
698   }
699   case IIT_TRUNC_ARG: {
700     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
701     OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncArgument,
702                                              ArgInfo));
703     return;
704   }
705   case IIT_HALF_VEC_ARG: {
706     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
707     OutputTable.push_back(IITDescriptor::get(IITDescriptor::HalfVecArgument,
708                                              ArgInfo));
709     return;
710   }
711   case IIT_SAME_VEC_WIDTH_ARG: {
712     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
713     OutputTable.push_back(IITDescriptor::get(IITDescriptor::SameVecWidthArgument,
714                                              ArgInfo));
715     return;
716   }
717   case IIT_PTR_TO_ARG: {
718     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
719     OutputTable.push_back(IITDescriptor::get(IITDescriptor::PtrToArgument,
720                                              ArgInfo));
721     return;
722   }
723   case IIT_PTR_TO_ELT: {
724     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
725     OutputTable.push_back(IITDescriptor::get(IITDescriptor::PtrToElt, ArgInfo));
726     return;
727   }
728   case IIT_VEC_OF_PTRS_TO_ELT: {
729     unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
730     OutputTable.push_back(IITDescriptor::get(IITDescriptor::VecOfPtrsToElt,
731                                              ArgInfo));
732     return;
733   }
734   case IIT_EMPTYSTRUCT:
735     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0));
736     return;
737   case IIT_STRUCT5: ++StructElts; LLVM_FALLTHROUGH;
738   case IIT_STRUCT4: ++StructElts; LLVM_FALLTHROUGH;
739   case IIT_STRUCT3: ++StructElts; LLVM_FALLTHROUGH;
740   case IIT_STRUCT2: {
741     OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts));
742 
743     for (unsigned i = 0; i != StructElts; ++i)
744       DecodeIITType(NextElt, Infos, OutputTable);
745     return;
746   }
747   }
748   llvm_unreachable("unhandled");
749 }
750 
751 
752 #define GET_INTRINSIC_GENERATOR_GLOBAL
753 #include "llvm/IR/Intrinsics.gen"
754 #undef GET_INTRINSIC_GENERATOR_GLOBAL
755 
756 void Intrinsic::getIntrinsicInfoTableEntries(ID id,
757                                              SmallVectorImpl<IITDescriptor> &T){
758   // Check to see if the intrinsic's type was expressible by the table.
759   unsigned TableVal = IIT_Table[id-1];
760 
761   // Decode the TableVal into an array of IITValues.
762   SmallVector<unsigned char, 8> IITValues;
763   ArrayRef<unsigned char> IITEntries;
764   unsigned NextElt = 0;
765   if ((TableVal >> 31) != 0) {
766     // This is an offset into the IIT_LongEncodingTable.
767     IITEntries = IIT_LongEncodingTable;
768 
769     // Strip sentinel bit.
770     NextElt = (TableVal << 1) >> 1;
771   } else {
772     // Decode the TableVal into an array of IITValues.  If the entry was encoded
773     // into a single word in the table itself, decode it now.
774     do {
775       IITValues.push_back(TableVal & 0xF);
776       TableVal >>= 4;
777     } while (TableVal);
778 
779     IITEntries = IITValues;
780     NextElt = 0;
781   }
782 
783   // Okay, decode the table into the output vector of IITDescriptors.
784   DecodeIITType(NextElt, IITEntries, T);
785   while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0)
786     DecodeIITType(NextElt, IITEntries, T);
787 }
788 
789 
790 static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos,
791                              ArrayRef<Type*> Tys, LLVMContext &Context) {
792   using namespace Intrinsic;
793   IITDescriptor D = Infos.front();
794   Infos = Infos.slice(1);
795 
796   switch (D.Kind) {
797   case IITDescriptor::Void: return Type::getVoidTy(Context);
798   case IITDescriptor::VarArg: return Type::getVoidTy(Context);
799   case IITDescriptor::MMX: return Type::getX86_MMXTy(Context);
800   case IITDescriptor::Token: return Type::getTokenTy(Context);
801   case IITDescriptor::Metadata: return Type::getMetadataTy(Context);
802   case IITDescriptor::Half: return Type::getHalfTy(Context);
803   case IITDescriptor::Float: return Type::getFloatTy(Context);
804   case IITDescriptor::Double: return Type::getDoubleTy(Context);
805 
806   case IITDescriptor::Integer:
807     return IntegerType::get(Context, D.Integer_Width);
808   case IITDescriptor::Vector:
809     return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width);
810   case IITDescriptor::Pointer:
811     return PointerType::get(DecodeFixedType(Infos, Tys, Context),
812                             D.Pointer_AddressSpace);
813   case IITDescriptor::Struct: {
814     Type *Elts[5];
815     assert(D.Struct_NumElements <= 5 && "Can't handle this yet");
816     for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
817       Elts[i] = DecodeFixedType(Infos, Tys, Context);
818     return StructType::get(Context, makeArrayRef(Elts,D.Struct_NumElements));
819   }
820 
821   case IITDescriptor::Argument:
822     return Tys[D.getArgumentNumber()];
823   case IITDescriptor::ExtendArgument: {
824     Type *Ty = Tys[D.getArgumentNumber()];
825     if (VectorType *VTy = dyn_cast<VectorType>(Ty))
826       return VectorType::getExtendedElementVectorType(VTy);
827 
828     return IntegerType::get(Context, 2 * cast<IntegerType>(Ty)->getBitWidth());
829   }
830   case IITDescriptor::TruncArgument: {
831     Type *Ty = Tys[D.getArgumentNumber()];
832     if (VectorType *VTy = dyn_cast<VectorType>(Ty))
833       return VectorType::getTruncatedElementVectorType(VTy);
834 
835     IntegerType *ITy = cast<IntegerType>(Ty);
836     assert(ITy->getBitWidth() % 2 == 0);
837     return IntegerType::get(Context, ITy->getBitWidth() / 2);
838   }
839   case IITDescriptor::HalfVecArgument:
840     return VectorType::getHalfElementsVectorType(cast<VectorType>(
841                                                   Tys[D.getArgumentNumber()]));
842   case IITDescriptor::SameVecWidthArgument: {
843     Type *EltTy = DecodeFixedType(Infos, Tys, Context);
844     Type *Ty = Tys[D.getArgumentNumber()];
845     if (VectorType *VTy = dyn_cast<VectorType>(Ty)) {
846       return VectorType::get(EltTy, VTy->getNumElements());
847     }
848     llvm_unreachable("unhandled");
849   }
850   case IITDescriptor::PtrToArgument: {
851     Type *Ty = Tys[D.getArgumentNumber()];
852     return PointerType::getUnqual(Ty);
853   }
854   case IITDescriptor::PtrToElt: {
855     Type *Ty = Tys[D.getArgumentNumber()];
856     VectorType *VTy = dyn_cast<VectorType>(Ty);
857     if (!VTy)
858       llvm_unreachable("Expected an argument of Vector Type");
859     Type *EltTy = VTy->getVectorElementType();
860     return PointerType::getUnqual(EltTy);
861   }
862   case IITDescriptor::VecOfPtrsToElt: {
863     Type *Ty = Tys[D.getArgumentNumber()];
864     VectorType *VTy = dyn_cast<VectorType>(Ty);
865     if (!VTy)
866       llvm_unreachable("Expected an argument of Vector Type");
867     Type *EltTy = VTy->getVectorElementType();
868     return VectorType::get(PointerType::getUnqual(EltTy),
869                            VTy->getNumElements());
870   }
871  }
872   llvm_unreachable("unhandled");
873 }
874 
875 
876 
877 FunctionType *Intrinsic::getType(LLVMContext &Context,
878                                  ID id, ArrayRef<Type*> Tys) {
879   SmallVector<IITDescriptor, 8> Table;
880   getIntrinsicInfoTableEntries(id, Table);
881 
882   ArrayRef<IITDescriptor> TableRef = Table;
883   Type *ResultTy = DecodeFixedType(TableRef, Tys, Context);
884 
885   SmallVector<Type*, 8> ArgTys;
886   while (!TableRef.empty())
887     ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context));
888 
889   // DecodeFixedType returns Void for IITDescriptor::Void and IITDescriptor::VarArg
890   // If we see void type as the type of the last argument, it is vararg intrinsic
891   if (!ArgTys.empty() && ArgTys.back()->isVoidTy()) {
892     ArgTys.pop_back();
893     return FunctionType::get(ResultTy, ArgTys, true);
894   }
895   return FunctionType::get(ResultTy, ArgTys, false);
896 }
897 
898 bool Intrinsic::isOverloaded(ID id) {
899 #define GET_INTRINSIC_OVERLOAD_TABLE
900 #include "llvm/IR/Intrinsics.gen"
901 #undef GET_INTRINSIC_OVERLOAD_TABLE
902 }
903 
904 bool Intrinsic::isLeaf(ID id) {
905   switch (id) {
906   default:
907     return true;
908 
909   case Intrinsic::experimental_gc_statepoint:
910   case Intrinsic::experimental_patchpoint_void:
911   case Intrinsic::experimental_patchpoint_i64:
912     return false;
913   }
914 }
915 
916 /// This defines the "Intrinsic::getAttributes(ID id)" method.
917 #define GET_INTRINSIC_ATTRIBUTES
918 #include "llvm/IR/Intrinsics.gen"
919 #undef GET_INTRINSIC_ATTRIBUTES
920 
921 Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
922   // There can never be multiple globals with the same name of different types,
923   // because intrinsics must be a specific type.
924   return
925     cast<Function>(M->getOrInsertFunction(getName(id, Tys),
926                                           getType(M->getContext(), id, Tys)));
927 }
928 
929 // This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
930 #define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
931 #include "llvm/IR/Intrinsics.gen"
932 #undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
933 
934 // This defines the "Intrinsic::getIntrinsicForMSBuiltin()" method.
935 #define GET_LLVM_INTRINSIC_FOR_MS_BUILTIN
936 #include "llvm/IR/Intrinsics.gen"
937 #undef GET_LLVM_INTRINSIC_FOR_MS_BUILTIN
938 
939 bool Intrinsic::matchIntrinsicType(Type *Ty, ArrayRef<Intrinsic::IITDescriptor> &Infos,
940                                    SmallVectorImpl<Type*> &ArgTys) {
941   using namespace Intrinsic;
942 
943   // If we ran out of descriptors, there are too many arguments.
944   if (Infos.empty()) return true;
945   IITDescriptor D = Infos.front();
946   Infos = Infos.slice(1);
947 
948   switch (D.Kind) {
949     case IITDescriptor::Void: return !Ty->isVoidTy();
950     case IITDescriptor::VarArg: return true;
951     case IITDescriptor::MMX:  return !Ty->isX86_MMXTy();
952     case IITDescriptor::Token: return !Ty->isTokenTy();
953     case IITDescriptor::Metadata: return !Ty->isMetadataTy();
954     case IITDescriptor::Half: return !Ty->isHalfTy();
955     case IITDescriptor::Float: return !Ty->isFloatTy();
956     case IITDescriptor::Double: return !Ty->isDoubleTy();
957     case IITDescriptor::Integer: return !Ty->isIntegerTy(D.Integer_Width);
958     case IITDescriptor::Vector: {
959       VectorType *VT = dyn_cast<VectorType>(Ty);
960       return !VT || VT->getNumElements() != D.Vector_Width ||
961              matchIntrinsicType(VT->getElementType(), Infos, ArgTys);
962     }
963     case IITDescriptor::Pointer: {
964       PointerType *PT = dyn_cast<PointerType>(Ty);
965       return !PT || PT->getAddressSpace() != D.Pointer_AddressSpace ||
966              matchIntrinsicType(PT->getElementType(), Infos, ArgTys);
967     }
968 
969     case IITDescriptor::Struct: {
970       StructType *ST = dyn_cast<StructType>(Ty);
971       if (!ST || ST->getNumElements() != D.Struct_NumElements)
972         return true;
973 
974       for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
975         if (matchIntrinsicType(ST->getElementType(i), Infos, ArgTys))
976           return true;
977       return false;
978     }
979 
980     case IITDescriptor::Argument:
981       // Two cases here - If this is the second occurrence of an argument, verify
982       // that the later instance matches the previous instance.
983       if (D.getArgumentNumber() < ArgTys.size())
984         return Ty != ArgTys[D.getArgumentNumber()];
985 
986           // Otherwise, if this is the first instance of an argument, record it and
987           // verify the "Any" kind.
988           assert(D.getArgumentNumber() == ArgTys.size() && "Table consistency error");
989           ArgTys.push_back(Ty);
990 
991           switch (D.getArgumentKind()) {
992             case IITDescriptor::AK_Any:        return false; // Success
993             case IITDescriptor::AK_AnyInteger: return !Ty->isIntOrIntVectorTy();
994             case IITDescriptor::AK_AnyFloat:   return !Ty->isFPOrFPVectorTy();
995             case IITDescriptor::AK_AnyVector:  return !isa<VectorType>(Ty);
996             case IITDescriptor::AK_AnyPointer: return !isa<PointerType>(Ty);
997           }
998           llvm_unreachable("all argument kinds not covered");
999 
1000     case IITDescriptor::ExtendArgument: {
1001       // This may only be used when referring to a previous vector argument.
1002       if (D.getArgumentNumber() >= ArgTys.size())
1003         return true;
1004 
1005       Type *NewTy = ArgTys[D.getArgumentNumber()];
1006       if (VectorType *VTy = dyn_cast<VectorType>(NewTy))
1007         NewTy = VectorType::getExtendedElementVectorType(VTy);
1008       else if (IntegerType *ITy = dyn_cast<IntegerType>(NewTy))
1009         NewTy = IntegerType::get(ITy->getContext(), 2 * ITy->getBitWidth());
1010       else
1011         return true;
1012 
1013       return Ty != NewTy;
1014     }
1015     case IITDescriptor::TruncArgument: {
1016       // This may only be used when referring to a previous vector argument.
1017       if (D.getArgumentNumber() >= ArgTys.size())
1018         return true;
1019 
1020       Type *NewTy = ArgTys[D.getArgumentNumber()];
1021       if (VectorType *VTy = dyn_cast<VectorType>(NewTy))
1022         NewTy = VectorType::getTruncatedElementVectorType(VTy);
1023       else if (IntegerType *ITy = dyn_cast<IntegerType>(NewTy))
1024         NewTy = IntegerType::get(ITy->getContext(), ITy->getBitWidth() / 2);
1025       else
1026         return true;
1027 
1028       return Ty != NewTy;
1029     }
1030     case IITDescriptor::HalfVecArgument:
1031       // This may only be used when referring to a previous vector argument.
1032       return D.getArgumentNumber() >= ArgTys.size() ||
1033              !isa<VectorType>(ArgTys[D.getArgumentNumber()]) ||
1034              VectorType::getHalfElementsVectorType(
1035                      cast<VectorType>(ArgTys[D.getArgumentNumber()])) != Ty;
1036     case IITDescriptor::SameVecWidthArgument: {
1037       if (D.getArgumentNumber() >= ArgTys.size())
1038         return true;
1039       VectorType * ReferenceType =
1040         dyn_cast<VectorType>(ArgTys[D.getArgumentNumber()]);
1041       VectorType *ThisArgType = dyn_cast<VectorType>(Ty);
1042       if (!ThisArgType || !ReferenceType ||
1043           (ReferenceType->getVectorNumElements() !=
1044            ThisArgType->getVectorNumElements()))
1045         return true;
1046       return matchIntrinsicType(ThisArgType->getVectorElementType(),
1047                                 Infos, ArgTys);
1048     }
1049     case IITDescriptor::PtrToArgument: {
1050       if (D.getArgumentNumber() >= ArgTys.size())
1051         return true;
1052       Type * ReferenceType = ArgTys[D.getArgumentNumber()];
1053       PointerType *ThisArgType = dyn_cast<PointerType>(Ty);
1054       return (!ThisArgType || ThisArgType->getElementType() != ReferenceType);
1055     }
1056     case IITDescriptor::PtrToElt: {
1057       if (D.getArgumentNumber() >= ArgTys.size())
1058         return true;
1059       VectorType * ReferenceType =
1060         dyn_cast<VectorType> (ArgTys[D.getArgumentNumber()]);
1061       PointerType *ThisArgType = dyn_cast<PointerType>(Ty);
1062 
1063       return (!ThisArgType || !ReferenceType ||
1064               ThisArgType->getElementType() != ReferenceType->getElementType());
1065     }
1066     case IITDescriptor::VecOfPtrsToElt: {
1067       if (D.getArgumentNumber() >= ArgTys.size())
1068         return true;
1069       VectorType * ReferenceType =
1070               dyn_cast<VectorType> (ArgTys[D.getArgumentNumber()]);
1071       VectorType *ThisArgVecTy = dyn_cast<VectorType>(Ty);
1072       if (!ThisArgVecTy || !ReferenceType ||
1073           (ReferenceType->getVectorNumElements() !=
1074            ThisArgVecTy->getVectorNumElements()))
1075         return true;
1076       PointerType *ThisArgEltTy =
1077               dyn_cast<PointerType>(ThisArgVecTy->getVectorElementType());
1078       if (!ThisArgEltTy)
1079         return true;
1080       return ThisArgEltTy->getElementType() !=
1081              ReferenceType->getVectorElementType();
1082     }
1083   }
1084   llvm_unreachable("unhandled");
1085 }
1086 
1087 bool
1088 Intrinsic::matchIntrinsicVarArg(bool isVarArg,
1089                                 ArrayRef<Intrinsic::IITDescriptor> &Infos) {
1090   // If there are no descriptors left, then it can't be a vararg.
1091   if (Infos.empty())
1092     return isVarArg;
1093 
1094   // There should be only one descriptor remaining at this point.
1095   if (Infos.size() != 1)
1096     return true;
1097 
1098   // Check and verify the descriptor.
1099   IITDescriptor D = Infos.front();
1100   Infos = Infos.slice(1);
1101   if (D.Kind == IITDescriptor::VarArg)
1102     return !isVarArg;
1103 
1104   return true;
1105 }
1106 
1107 Optional<Function*> Intrinsic::remangleIntrinsicFunction(Function *F) {
1108   Intrinsic::ID ID = F->getIntrinsicID();
1109   if (!ID)
1110     return None;
1111 
1112   FunctionType *FTy = F->getFunctionType();
1113   // Accumulate an array of overloaded types for the given intrinsic
1114   SmallVector<Type *, 4> ArgTys;
1115   {
1116     SmallVector<Intrinsic::IITDescriptor, 8> Table;
1117     getIntrinsicInfoTableEntries(ID, Table);
1118     ArrayRef<Intrinsic::IITDescriptor> TableRef = Table;
1119 
1120     // If we encounter any problems matching the signature with the descriptor
1121     // just give up remangling. It's up to verifier to report the discrepancy.
1122     if (Intrinsic::matchIntrinsicType(FTy->getReturnType(), TableRef, ArgTys))
1123       return None;
1124     for (auto Ty : FTy->params())
1125       if (Intrinsic::matchIntrinsicType(Ty, TableRef, ArgTys))
1126         return None;
1127     if (Intrinsic::matchIntrinsicVarArg(FTy->isVarArg(), TableRef))
1128       return None;
1129   }
1130 
1131   StringRef Name = F->getName();
1132   if (Name == Intrinsic::getName(ID, ArgTys))
1133     return None;
1134 
1135   auto NewDecl = Intrinsic::getDeclaration(F->getParent(), ID, ArgTys);
1136   NewDecl->setCallingConv(F->getCallingConv());
1137   assert(NewDecl->getFunctionType() == FTy && "Shouldn't change the signature");
1138   return NewDecl;
1139 }
1140 
1141 /// hasAddressTaken - returns true if there are any uses of this function
1142 /// other than direct calls or invokes to it.
1143 bool Function::hasAddressTaken(const User* *PutOffender) const {
1144   for (const Use &U : uses()) {
1145     const User *FU = U.getUser();
1146     if (isa<BlockAddress>(FU))
1147       continue;
1148     if (!isa<CallInst>(FU) && !isa<InvokeInst>(FU)) {
1149       if (PutOffender)
1150         *PutOffender = FU;
1151       return true;
1152     }
1153     ImmutableCallSite CS(cast<Instruction>(FU));
1154     if (!CS.isCallee(&U)) {
1155       if (PutOffender)
1156         *PutOffender = FU;
1157       return true;
1158     }
1159   }
1160   return false;
1161 }
1162 
1163 bool Function::isDefTriviallyDead() const {
1164   // Check the linkage
1165   if (!hasLinkOnceLinkage() && !hasLocalLinkage() &&
1166       !hasAvailableExternallyLinkage())
1167     return false;
1168 
1169   // Check if the function is used by anything other than a blockaddress.
1170   for (const User *U : users())
1171     if (!isa<BlockAddress>(U))
1172       return false;
1173 
1174   return true;
1175 }
1176 
1177 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
1178 /// setjmp or other function that gcc recognizes as "returning twice".
1179 bool Function::callsFunctionThatReturnsTwice() const {
1180   for (const_inst_iterator
1181          I = inst_begin(this), E = inst_end(this); I != E; ++I) {
1182     ImmutableCallSite CS(&*I);
1183     if (CS && CS.hasFnAttr(Attribute::ReturnsTwice))
1184       return true;
1185   }
1186 
1187   return false;
1188 }
1189 
1190 Constant *Function::getPersonalityFn() const {
1191   assert(hasPersonalityFn() && getNumOperands());
1192   return cast<Constant>(Op<0>());
1193 }
1194 
1195 void Function::setPersonalityFn(Constant *Fn) {
1196   setHungoffOperand<0>(Fn);
1197   setValueSubclassDataBit(3, Fn != nullptr);
1198 }
1199 
1200 Constant *Function::getPrefixData() const {
1201   assert(hasPrefixData() && getNumOperands());
1202   return cast<Constant>(Op<1>());
1203 }
1204 
1205 void Function::setPrefixData(Constant *PrefixData) {
1206   setHungoffOperand<1>(PrefixData);
1207   setValueSubclassDataBit(1, PrefixData != nullptr);
1208 }
1209 
1210 Constant *Function::getPrologueData() const {
1211   assert(hasPrologueData() && getNumOperands());
1212   return cast<Constant>(Op<2>());
1213 }
1214 
1215 void Function::setPrologueData(Constant *PrologueData) {
1216   setHungoffOperand<2>(PrologueData);
1217   setValueSubclassDataBit(2, PrologueData != nullptr);
1218 }
1219 
1220 void Function::allocHungoffUselist() {
1221   // If we've already allocated a uselist, stop here.
1222   if (getNumOperands())
1223     return;
1224 
1225   allocHungoffUses(3, /*IsPhi=*/ false);
1226   setNumHungOffUseOperands(3);
1227 
1228   // Initialize the uselist with placeholder operands to allow traversal.
1229   auto *CPN = ConstantPointerNull::get(Type::getInt1PtrTy(getContext(), 0));
1230   Op<0>().set(CPN);
1231   Op<1>().set(CPN);
1232   Op<2>().set(CPN);
1233 }
1234 
1235 template <int Idx>
1236 void Function::setHungoffOperand(Constant *C) {
1237   if (C) {
1238     allocHungoffUselist();
1239     Op<Idx>().set(C);
1240   } else if (getNumOperands()) {
1241     Op<Idx>().set(
1242         ConstantPointerNull::get(Type::getInt1PtrTy(getContext(), 0)));
1243   }
1244 }
1245 
1246 void Function::setValueSubclassDataBit(unsigned Bit, bool On) {
1247   assert(Bit < 16 && "SubclassData contains only 16 bits");
1248   if (On)
1249     setValueSubclassData(getSubclassDataFromValue() | (1 << Bit));
1250   else
1251     setValueSubclassData(getSubclassDataFromValue() & ~(1 << Bit));
1252 }
1253 
1254 void Function::setEntryCount(uint64_t Count) {
1255   MDBuilder MDB(getContext());
1256   setMetadata(LLVMContext::MD_prof, MDB.createFunctionEntryCount(Count));
1257 }
1258 
1259 Optional<uint64_t> Function::getEntryCount() const {
1260   MDNode *MD = getMetadata(LLVMContext::MD_prof);
1261   if (MD && MD->getOperand(0))
1262     if (MDString *MDS = dyn_cast<MDString>(MD->getOperand(0)))
1263       if (MDS->getString().equals("function_entry_count")) {
1264         ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(1));
1265         uint64_t Count = CI->getValue().getZExtValue();
1266         if (Count == 0)
1267           return None;
1268         return Count;
1269       }
1270   return None;
1271 }
1272 
1273 void Function::setSectionPrefix(StringRef Prefix) {
1274   MDBuilder MDB(getContext());
1275   setMetadata(LLVMContext::MD_section_prefix,
1276               MDB.createFunctionSectionPrefix(Prefix));
1277 }
1278 
1279 Optional<StringRef> Function::getSectionPrefix() const {
1280   if (MDNode *MD = getMetadata(LLVMContext::MD_section_prefix)) {
1281     assert(dyn_cast<MDString>(MD->getOperand(0))
1282                ->getString()
1283                .equals("function_section_prefix") &&
1284            "Metadata not match");
1285     return dyn_cast<MDString>(MD->getOperand(1))->getString();
1286   }
1287   return None;
1288 }
1289