Function.cpp revision 1e3037f0be430ef2339838bbdede11f45658bd82 
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/DenseMap.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/CodeGen/ValueTypes.h"
21#include "llvm/IR/DerivedTypes.h"
22#include "llvm/IR/IntrinsicInst.h"
23#include "llvm/IR/LLVMContext.h"
24#include "llvm/IR/Module.h"
25#include "llvm/Support/CallSite.h"
26#include "llvm/Support/InstIterator.h"
27#include "llvm/Support/LeakDetector.h"
28#include "llvm/Support/ManagedStatic.h"
29#include "llvm/Support/RWMutex.h"
30#include "llvm/Support/StringPool.h"
31#include "llvm/Support/Threading.h"
32using namespace llvm;
33
34// Explicit instantiations of SymbolTableListTraits since some of the methods
35// are not in the public header file...
36template class llvm::SymbolTableListTraits<Argument, Function>;
37template class llvm::SymbolTableListTraits<BasicBlock, Function>;
38
39//===----------------------------------------------------------------------===//
40// Argument Implementation
41//===----------------------------------------------------------------------===//
42
43void Argument::anchor() { }
44
45Argument::Argument(Type *Ty, const Twine &Name, Function *Par)
46  : Value(Ty, Value::ArgumentVal) {
47  Parent = 0;
48
49  // Make sure that we get added to a function
50  LeakDetector::addGarbageObject(this);
51
52  if (Par)
53    Par->getArgumentList().push_back(this);
54  setName(Name);
55}
56
57void Argument::setParent(Function *parent) {
58  if (getParent())
59    LeakDetector::addGarbageObject(this);
60  Parent = parent;
61  if (getParent())
62    LeakDetector::removeGarbageObject(this);
63}
64
65/// getArgNo - Return the index of this formal argument in its containing
66/// function.  For example in "void foo(int a, float b)" a is 0 and b is 1.
67unsigned Argument::getArgNo() const {
68  const Function *F = getParent();
69  assert(F && "Argument is not in a function");
70
71  Function::const_arg_iterator AI = F->arg_begin();
72  unsigned ArgIdx = 0;
73  for (; &*AI != this; ++AI)
74    ++ArgIdx;
75
76  return ArgIdx;
77}
78
79/// hasByValAttr - Return true if this argument has the byval attribute on it
80/// in its containing function.
81bool Argument::hasByValAttr() const {
82  if (!getType()->isPointerTy()) return false;
83  return getParent()->getAttributes().
84    hasAttribute(getArgNo()+1, Attribute::ByVal);
85}
86
87unsigned Argument::getParamAlignment() const {
88  assert(getType()->isPointerTy() && "Only pointers have alignments");
89  return getParent()->getParamAlignment(getArgNo()+1);
90
91}
92
93/// hasNestAttr - Return true if this argument has the nest attribute on
94/// it in its containing function.
95bool Argument::hasNestAttr() const {
96  if (!getType()->isPointerTy()) return false;
97  return getParent()->getAttributes().
98    hasAttribute(getArgNo()+1, Attribute::Nest);
99}
100
101/// hasNoAliasAttr - Return true if this argument has the noalias attribute on
102/// it in its containing function.
103bool Argument::hasNoAliasAttr() const {
104  if (!getType()->isPointerTy()) return false;
105  return getParent()->getAttributes().
106    hasAttribute(getArgNo()+1, Attribute::NoAlias);
107}
108
109/// hasNoCaptureAttr - Return true if this argument has the nocapture attribute
110/// on it in its containing function.
111bool Argument::hasNoCaptureAttr() const {
112  if (!getType()->isPointerTy()) return false;
113  return getParent()->getAttributes().
114    hasAttribute(getArgNo()+1, Attribute::NoCapture);
115}
116
117/// hasSRetAttr - Return true if this argument has the sret attribute on
118/// it in its containing function.
119bool Argument::hasStructRetAttr() const {
120  if (!getType()->isPointerTy()) return false;
121  if (this != getParent()->arg_begin())
122    return false; // StructRet param must be first param
123  return getParent()->getAttributes().
124    hasAttribute(1, Attribute::StructRet);
125}
126
127/// hasReturnedAttr - Return true if this argument has the returned attribute on
128/// it in its containing function.
129bool Argument::hasReturnedAttr() const {
130  return getParent()->getAttributes().
131    hasAttribute(getArgNo()+1, Attribute::Returned);
132}
133
134/// Return true if this argument has the readonly or readnone attribute on it
135/// in its containing function.
136bool Argument::onlyReadsMemory() const {
137  return getParent()->getAttributes().
138      hasAttribute(getArgNo()+1, Attribute::ReadOnly) ||
139      getParent()->getAttributes().
140      hasAttribute(getArgNo()+1, Attribute::ReadNone);
141}
142
143/// addAttr - Add attributes to an argument.
144void Argument::addAttr(AttributeSet AS) {
145  assert(AS.getNumSlots() <= 1 &&
146         "Trying to add more than one attribute set to an argument!");
147  AttrBuilder B(AS, AS.getSlotIndex(0));
148  getParent()->addAttributes(getArgNo() + 1,
149                             AttributeSet::get(Parent->getContext(),
150                                               getArgNo() + 1, B));
151}
152
153/// removeAttr - Remove attributes from an argument.
154void Argument::removeAttr(AttributeSet AS) {
155  assert(AS.getNumSlots() <= 1 &&
156         "Trying to remove more than one attribute set from an argument!");
157  AttrBuilder B(AS, AS.getSlotIndex(0));
158  getParent()->removeAttributes(getArgNo() + 1,
159                                AttributeSet::get(Parent->getContext(),
160                                                  getArgNo() + 1, B));
161}
162
163//===----------------------------------------------------------------------===//
164// Helper Methods in Function
165//===----------------------------------------------------------------------===//
166
167LLVMContext &Function::getContext() const {
168  return getType()->getContext();
169}
170
171FunctionType *Function::getFunctionType() const {
172  return cast<FunctionType>(getType()->getElementType());
173}
174
175bool Function::isVarArg() const {
176  return getFunctionType()->isVarArg();
177}
178
179Type *Function::getReturnType() const {
180  return getFunctionType()->getReturnType();
181}
182
183void Function::removeFromParent() {
184  getParent()->getFunctionList().remove(this);
185}
186
187void Function::eraseFromParent() {
188  getParent()->getFunctionList().erase(this);
189}
190
191//===----------------------------------------------------------------------===//
192// Function Implementation
193//===----------------------------------------------------------------------===//
194
195Function::Function(FunctionType *Ty, LinkageTypes Linkage,
196                   const Twine &name, Module *ParentModule)
197  : GlobalValue(PointerType::getUnqual(Ty),
198                Value::FunctionVal, 0, 0, Linkage, name) {
199  assert(FunctionType::isValidReturnType(getReturnType()) &&
200         "invalid return type");
201  SymTab = new ValueSymbolTable();
202
203  // If the function has arguments, mark them as lazily built.
204  if (Ty->getNumParams())
205    setValueSubclassData(1);   // Set the "has lazy arguments" bit.
206
207  // Make sure that we get added to a function
208  LeakDetector::addGarbageObject(this);
209
210  if (ParentModule)
211    ParentModule->getFunctionList().push_back(this);
212
213  // Ensure intrinsics have the right parameter attributes.
214  if (unsigned IID = getIntrinsicID())
215    setAttributes(Intrinsic::getAttributes(getContext(), Intrinsic::ID(IID)));
216
217}
218
219Function::~Function() {
220  dropAllReferences();    // After this it is safe to delete instructions.
221
222  // Delete all of the method arguments and unlink from symbol table...
223  ArgumentList.clear();
224  delete SymTab;
225
226  // Remove the function from the on-the-side GC table.
227  clearGC();
228
229  // Remove the intrinsicID from the Cache.
230  if (getValueName() && isIntrinsic())
231    getContext().pImpl->IntrinsicIDCache.erase(this);
232}
233
234void Function::BuildLazyArguments() const {
235  // Create the arguments vector, all arguments start out unnamed.
236  FunctionType *FT = getFunctionType();
237  for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
238    assert(!FT->getParamType(i)->isVoidTy() &&
239           "Cannot have void typed arguments!");
240    ArgumentList.push_back(new Argument(FT->getParamType(i)));
241  }
242
243  // Clear the lazy arguments bit.
244  unsigned SDC = getSubclassDataFromValue();
245  const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1);
246}
247
248size_t Function::arg_size() const {
249  return getFunctionType()->getNumParams();
250}
251bool Function::arg_empty() const {
252  return getFunctionType()->getNumParams() == 0;
253}
254
255void Function::setParent(Module *parent) {
256  if (getParent())
257    LeakDetector::addGarbageObject(this);
258  Parent = parent;
259  if (getParent())
260    LeakDetector::removeGarbageObject(this);
261}
262
263// dropAllReferences() - This function causes all the subinstructions to "let
264// go" of all references that they are maintaining.  This allows one to
265// 'delete' a whole class at a time, even though there may be circular
266// references... first all references are dropped, and all use counts go to
267// zero.  Then everything is deleted for real.  Note that no operations are
268// valid on an object that has "dropped all references", except operator
269// delete.
270//
271void Function::dropAllReferences() {
272  for (iterator I = begin(), E = end(); I != E; ++I)
273    I->dropAllReferences();
274
275  // Delete all basic blocks. They are now unused, except possibly by
276  // blockaddresses, but BasicBlock's destructor takes care of those.
277  while (!BasicBlocks.empty())
278    BasicBlocks.begin()->eraseFromParent();
279
280  // Prefix data is stored in a side table.
281  setPrefixData(0);
282}
283
284void Function::addAttribute(unsigned i, Attribute::AttrKind attr) {
285  AttributeSet PAL = getAttributes();
286  PAL = PAL.addAttribute(getContext(), i, attr);
287  setAttributes(PAL);
288}
289
290void Function::addAttributes(unsigned i, AttributeSet attrs) {
291  AttributeSet PAL = getAttributes();
292  PAL = PAL.addAttributes(getContext(), i, attrs);
293  setAttributes(PAL);
294}
295
296void Function::removeAttributes(unsigned i, AttributeSet attrs) {
297  AttributeSet PAL = getAttributes();
298  PAL = PAL.removeAttributes(getContext(), i, attrs);
299  setAttributes(PAL);
300}
301
302// Maintain the GC name for each function in an on-the-side table. This saves
303// allocating an additional word in Function for programs which do not use GC
304// (i.e., most programs) at the cost of increased overhead for clients which do
305// use GC.
306static DenseMap<const Function*,PooledStringPtr> *GCNames;
307static StringPool *GCNamePool;
308static ManagedStatic<sys::SmartRWMutex<true> > GCLock;
309
310bool Function::hasGC() const {
311  sys::SmartScopedReader<true> Reader(*GCLock);
312  return GCNames && GCNames->count(this);
313}
314
315const char *Function::getGC() const {
316  assert(hasGC() && "Function has no collector");
317  sys::SmartScopedReader<true> Reader(*GCLock);
318  return *(*GCNames)[this];
319}
320
321void Function::setGC(const char *Str) {
322  sys::SmartScopedWriter<true> Writer(*GCLock);
323  if (!GCNamePool)
324    GCNamePool = new StringPool();
325  if (!GCNames)
326    GCNames = new DenseMap<const Function*,PooledStringPtr>();
327  (*GCNames)[this] = GCNamePool->intern(Str);
328}
329
330void Function::clearGC() {
331  sys::SmartScopedWriter<true> Writer(*GCLock);
332  if (GCNames) {
333    GCNames->erase(this);
334    if (GCNames->empty()) {
335      delete GCNames;
336      GCNames = 0;
337      if (GCNamePool->empty()) {
338        delete GCNamePool;
339        GCNamePool = 0;
340      }
341    }
342  }
343}
344
345/// copyAttributesFrom - copy all additional attributes (those not needed to
346/// create a Function) from the Function Src to this one.
347void Function::copyAttributesFrom(const GlobalValue *Src) {
348  assert(isa<Function>(Src) && "Expected a Function!");
349  GlobalValue::copyAttributesFrom(Src);
350  const Function *SrcF = cast<Function>(Src);
351  setCallingConv(SrcF->getCallingConv());
352  setAttributes(SrcF->getAttributes());
353  if (SrcF->hasGC())
354    setGC(SrcF->getGC());
355  else
356    clearGC();
357  if (SrcF->hasPrefixData())
358    setPrefixData(SrcF->getPrefixData());
359  else
360    setPrefixData(0);
361}
362
363/// getIntrinsicID - This method returns the ID number of the specified
364/// function, or Intrinsic::not_intrinsic if the function is not an
365/// intrinsic, or if the pointer is null.  This value is always defined to be
366/// zero to allow easy checking for whether a function is intrinsic or not.  The
367/// particular intrinsic functions which correspond to this value are defined in
368/// llvm/Intrinsics.h.  Results are cached in the LLVM context, subsequent
369/// requests for the same ID return results much faster from the cache.
370///
371unsigned Function::getIntrinsicID() const {
372  const ValueName *ValName = this->getValueName();
373  if (!ValName || !isIntrinsic())
374    return 0;
375
376  LLVMContextImpl::IntrinsicIDCacheTy &IntrinsicIDCache =
377    getContext().pImpl->IntrinsicIDCache;
378  if (!IntrinsicIDCache.count(this)) {
379    unsigned Id = lookupIntrinsicID();
380    IntrinsicIDCache[this]=Id;
381    return Id;
382  }
383  return IntrinsicIDCache[this];
384}
385
386/// This private method does the actual lookup of an intrinsic ID when the query
387/// could not be answered from the cache.
388unsigned Function::lookupIntrinsicID() const {
389  const ValueName *ValName = this->getValueName();
390  unsigned Len = ValName->getKeyLength();
391  const char *Name = ValName->getKeyData();
392
393#define GET_FUNCTION_RECOGNIZER
394#include "llvm/IR/Intrinsics.gen"
395#undef GET_FUNCTION_RECOGNIZER
396
397  return 0;
398}
399
400std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
401  assert(id < num_intrinsics && "Invalid intrinsic ID!");
402  static const char * const Table[] = {
403    "not_intrinsic",
404#define GET_INTRINSIC_NAME_TABLE
405#include "llvm/IR/Intrinsics.gen"
406#undef GET_INTRINSIC_NAME_TABLE
407  };
408  if (Tys.empty())
409    return Table[id];
410  std::string Result(Table[id]);
411  for (unsigned i = 0; i < Tys.size(); ++i) {
412    if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
413      Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
414                EVT::getEVT(PTyp->getElementType()).getEVTString();
415    }
416    else if (Tys[i])
417      Result += "." + EVT::getEVT(Tys[i]).getEVTString();
418  }
419  return Result;
420}
421
422
423/// IIT_Info - These are enumerators that describe the entries returned by the
424/// getIntrinsicInfoTableEntries function.
425///
426/// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter!
427enum IIT_Info {
428  // Common values should be encoded with 0-15.
429  IIT_Done = 0,
430  IIT_I1   = 1,
431  IIT_I8   = 2,
432  IIT_I16  = 3,
433  IIT_I32  = 4,
434  IIT_I64  = 5,
435  IIT_F16  = 6,
436  IIT_F32  = 7,
437  IIT_F64  = 8,
438  IIT_V2   = 9,
439  IIT_V4   = 10,
440  IIT_V8   = 11,
441  IIT_V16  = 12,
442  IIT_V32  = 13,
443  IIT_PTR  = 14,
444  IIT_ARG  = 15,
445
446  // Values from 16+ are only encodable with the inefficient encoding.
447  IIT_MMX  = 16,
448  IIT_METADATA = 17,
449  IIT_EMPTYSTRUCT = 18,
450  IIT_STRUCT2 = 19,
451  IIT_STRUCT3 = 20,
452  IIT_STRUCT4 = 21,
453  IIT_STRUCT5 = 22,
454  IIT_EXTEND_VEC_ARG = 23,
455  IIT_TRUNC_VEC_ARG = 24,
456  IIT_ANYPTR = 25
457};
458
459
460static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
461                      SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) {
462  IIT_Info Info = IIT_Info(Infos[NextElt++]);
463  unsigned StructElts = 2;
464  using namespace Intrinsic;
465
466  switch (Info) {
467  case IIT_Done:
468    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0));
469    return;
470  case IIT_MMX:
471    OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0));
472    return;
473  case IIT_METADATA:
474    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0));
475    return;
476  case IIT_F16:
477    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Half, 0));
478    return;
479  case IIT_F32:
480    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0));
481    return;
482  case IIT_F64:
483    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0));
484    return;
485  case IIT_I1:
486    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1));
487    return;
488  case IIT_I8:
489    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8));
490    return;
491  case IIT_I16:
492    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16));
493    return;
494  case IIT_I32:
495    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32));
496    return;
497  case IIT_I64:
498    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64));
499    return;
500  case IIT_V2:
501    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2));
502    DecodeIITType(NextElt, Infos, OutputTable);
503    return;
504  case IIT_V4:
505    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4));
506    DecodeIITType(NextElt, Infos, OutputTable);
507    return;
508  case IIT_V8:
509    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8));
510    DecodeIITType(NextElt, Infos, OutputTable);
511    return;
512  case IIT_V16:
513    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16));
514    DecodeIITType(NextElt, Infos, OutputTable);
515    return;
516  case IIT_V32:
517    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32));
518    DecodeIITType(NextElt, Infos, OutputTable);
519    return;
520  case IIT_PTR:
521    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0));
522    DecodeIITType(NextElt, Infos, OutputTable);
523    return;
524  case IIT_ANYPTR: {  // [ANYPTR addrspace, subtype]
525    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer,
526                                             Infos[NextElt++]));
527    DecodeIITType(NextElt, Infos, OutputTable);
528    return;
529  }
530  case IIT_ARG: {
531    unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
532    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo));
533    return;
534  }
535  case IIT_EXTEND_VEC_ARG: {
536    unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
537    OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendVecArgument,
538                                             ArgInfo));
539    return;
540  }
541  case IIT_TRUNC_VEC_ARG: {
542    unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
543    OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncVecArgument,
544                                             ArgInfo));
545    return;
546  }
547  case IIT_EMPTYSTRUCT:
548    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0));
549    return;
550  case IIT_STRUCT5: ++StructElts; // FALL THROUGH.
551  case IIT_STRUCT4: ++StructElts; // FALL THROUGH.
552  case IIT_STRUCT3: ++StructElts; // FALL THROUGH.
553  case IIT_STRUCT2: {
554    OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts));
555
556    for (unsigned i = 0; i != StructElts; ++i)
557      DecodeIITType(NextElt, Infos, OutputTable);
558    return;
559  }
560  }
561  llvm_unreachable("unhandled");
562}
563
564
565#define GET_INTRINSIC_GENERATOR_GLOBAL
566#include "llvm/IR/Intrinsics.gen"
567#undef GET_INTRINSIC_GENERATOR_GLOBAL
568
569void Intrinsic::getIntrinsicInfoTableEntries(ID id,
570                                             SmallVectorImpl<IITDescriptor> &T){
571  // Check to see if the intrinsic's type was expressible by the table.
572  unsigned TableVal = IIT_Table[id-1];
573
574  // Decode the TableVal into an array of IITValues.
575  SmallVector<unsigned char, 8> IITValues;
576  ArrayRef<unsigned char> IITEntries;
577  unsigned NextElt = 0;
578  if ((TableVal >> 31) != 0) {
579    // This is an offset into the IIT_LongEncodingTable.
580    IITEntries = IIT_LongEncodingTable;
581
582    // Strip sentinel bit.
583    NextElt = (TableVal << 1) >> 1;
584  } else {
585    // Decode the TableVal into an array of IITValues.  If the entry was encoded
586    // into a single word in the table itself, decode it now.
587    do {
588      IITValues.push_back(TableVal & 0xF);
589      TableVal >>= 4;
590    } while (TableVal);
591
592    IITEntries = IITValues;
593    NextElt = 0;
594  }
595
596  // Okay, decode the table into the output vector of IITDescriptors.
597  DecodeIITType(NextElt, IITEntries, T);
598  while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0)
599    DecodeIITType(NextElt, IITEntries, T);
600}
601
602
603static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos,
604                             ArrayRef<Type*> Tys, LLVMContext &Context) {
605  using namespace Intrinsic;
606  IITDescriptor D = Infos.front();
607  Infos = Infos.slice(1);
608
609  switch (D.Kind) {
610  case IITDescriptor::Void: return Type::getVoidTy(Context);
611  case IITDescriptor::MMX: return Type::getX86_MMXTy(Context);
612  case IITDescriptor::Metadata: return Type::getMetadataTy(Context);
613  case IITDescriptor::Half: return Type::getHalfTy(Context);
614  case IITDescriptor::Float: return Type::getFloatTy(Context);
615  case IITDescriptor::Double: return Type::getDoubleTy(Context);
616
617  case IITDescriptor::Integer:
618    return IntegerType::get(Context, D.Integer_Width);
619  case IITDescriptor::Vector:
620    return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width);
621  case IITDescriptor::Pointer:
622    return PointerType::get(DecodeFixedType(Infos, Tys, Context),
623                            D.Pointer_AddressSpace);
624  case IITDescriptor::Struct: {
625    Type *Elts[5];
626    assert(D.Struct_NumElements <= 5 && "Can't handle this yet");
627    for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
628      Elts[i] = DecodeFixedType(Infos, Tys, Context);
629    return StructType::get(Context, ArrayRef<Type*>(Elts,D.Struct_NumElements));
630  }
631
632  case IITDescriptor::Argument:
633    return Tys[D.getArgumentNumber()];
634  case IITDescriptor::ExtendVecArgument:
635    return VectorType::getExtendedElementVectorType(cast<VectorType>(
636                                                  Tys[D.getArgumentNumber()]));
637
638  case IITDescriptor::TruncVecArgument:
639    return VectorType::getTruncatedElementVectorType(cast<VectorType>(
640                                                  Tys[D.getArgumentNumber()]));
641  }
642  llvm_unreachable("unhandled");
643}
644
645
646
647FunctionType *Intrinsic::getType(LLVMContext &Context,
648                                 ID id, ArrayRef<Type*> Tys) {
649  SmallVector<IITDescriptor, 8> Table;
650  getIntrinsicInfoTableEntries(id, Table);
651
652  ArrayRef<IITDescriptor> TableRef = Table;
653  Type *ResultTy = DecodeFixedType(TableRef, Tys, Context);
654
655  SmallVector<Type*, 8> ArgTys;
656  while (!TableRef.empty())
657    ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context));
658
659  return FunctionType::get(ResultTy, ArgTys, false);
660}
661
662bool Intrinsic::isOverloaded(ID id) {
663#define GET_INTRINSIC_OVERLOAD_TABLE
664#include "llvm/IR/Intrinsics.gen"
665#undef GET_INTRINSIC_OVERLOAD_TABLE
666}
667
668/// This defines the "Intrinsic::getAttributes(ID id)" method.
669#define GET_INTRINSIC_ATTRIBUTES
670#include "llvm/IR/Intrinsics.gen"
671#undef GET_INTRINSIC_ATTRIBUTES
672
673Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
674  // There can never be multiple globals with the same name of different types,
675  // because intrinsics must be a specific type.
676  return
677    cast<Function>(M->getOrInsertFunction(getName(id, Tys),
678                                          getType(M->getContext(), id, Tys)));
679}
680
681// This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
682#define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
683#include "llvm/IR/Intrinsics.gen"
684#undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
685
686/// hasAddressTaken - returns true if there are any uses of this function
687/// other than direct calls or invokes to it.
688bool Function::hasAddressTaken(const User* *PutOffender) const {
689  for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
690    const User *U = *I;
691    if (isa<BlockAddress>(U))
692      continue;
693    if (!isa<CallInst>(U) && !isa<InvokeInst>(U))
694      return PutOffender ? (*PutOffender = U, true) : true;
695    ImmutableCallSite CS(cast<Instruction>(U));
696    if (!CS.isCallee(I))
697      return PutOffender ? (*PutOffender = U, true) : true;
698  }
699  return false;
700}
701
702bool Function::isDefTriviallyDead() const {
703  // Check the linkage
704  if (!hasLinkOnceLinkage() && !hasLocalLinkage() &&
705      !hasAvailableExternallyLinkage())
706    return false;
707
708  // Check if the function is used by anything other than a blockaddress.
709  for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I)
710    if (!isa<BlockAddress>(*I))
711      return false;
712
713  return true;
714}
715
716/// callsFunctionThatReturnsTwice - Return true if the function has a call to
717/// setjmp or other function that gcc recognizes as "returning twice".
718bool Function::callsFunctionThatReturnsTwice() const {
719  for (const_inst_iterator
720         I = inst_begin(this), E = inst_end(this); I != E; ++I) {
721    const CallInst* callInst = dyn_cast<CallInst>(&*I);
722    if (!callInst)
723      continue;
724    if (callInst->canReturnTwice())
725      return true;
726  }
727
728  return false;
729}
730
731Constant *Function::getPrefixData() const {
732  assert(hasPrefixData());
733  const LLVMContextImpl::PrefixDataMapTy &PDMap =
734      getContext().pImpl->PrefixDataMap;
735  assert(PDMap.find(this) != PDMap.end());
736  return cast<Constant>(PDMap.find(this)->second->getReturnValue());
737}
738
739void Function::setPrefixData(Constant *PrefixData) {
740  if (!PrefixData && !hasPrefixData())
741    return;
742
743  unsigned SCData = getSubclassDataFromValue();
744  LLVMContextImpl::PrefixDataMapTy &PDMap = getContext().pImpl->PrefixDataMap;
745  ReturnInst *&PDHolder = PDMap[this];
746  if (PrefixData) {
747    if (PDHolder)
748      PDHolder->setOperand(0, PrefixData);
749    else
750      PDHolder = ReturnInst::Create(getContext(), PrefixData);
751    SCData |= 2;
752  } else {
753    delete PDHolder;
754    PDMap.erase(this);
755    SCData &= ~2;
756  }
757  setValueSubclassData(SCData);
758}
759