1 //===-- TypesContext.h - Types-related Context Internals ------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines various helper methods and classes used by
11 // LLVMContextImpl for creating and managing types.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_TYPESCONTEXT_H
16 #define LLVM_TYPESCONTEXT_H
18 #include "llvm/ADT/STLExtras.h"
22 //===----------------------------------------------------------------------===//
23 // Derived Type Factory Functions
24 //===----------------------------------------------------------------------===//
27 /// getSubElementHash - Generate a hash value for all of the SubType's of this
28 /// type. The hash value is guaranteed to be zero if any of the subtypes are
29 /// an opaque type. Otherwise we try to mix them in as well as possible, but do
30 /// not look at the subtype's subtype's.
31 static unsigned getSubElementHash(const Type *Ty) {
33 for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
36 const Type *SubTy = I->get();
37 HashVal += SubTy->getTypeID();
38 switch (SubTy->getTypeID()) {
40 case Type::OpaqueTyID: return 0; // Opaque -> hash = 0 no matter what.
41 case Type::IntegerTyID:
42 HashVal ^= (cast<IntegerType>(SubTy)->getBitWidth() << 3);
44 case Type::FunctionTyID:
45 HashVal ^= cast<FunctionType>(SubTy)->getNumParams()*2 +
46 cast<FunctionType>(SubTy)->isVarArg();
49 HashVal ^= cast<ArrayType>(SubTy)->getNumElements();
51 case Type::VectorTyID:
52 HashVal ^= cast<VectorType>(SubTy)->getNumElements();
54 case Type::StructTyID:
55 HashVal ^= cast<StructType>(SubTy)->getNumElements();
57 case Type::PointerTyID:
58 HashVal ^= cast<PointerType>(SubTy)->getAddressSpace();
62 return HashVal ? HashVal : 1; // Do not return zero unless opaque subty.
65 //===----------------------------------------------------------------------===//
66 // Integer Type Factory...
68 class IntegerValType {
71 IntegerValType(uint32_t numbits) : bits(numbits) {}
73 static IntegerValType get(const IntegerType *Ty) {
74 return IntegerValType(Ty->getBitWidth());
77 static unsigned hashTypeStructure(const IntegerType *Ty) {
78 return (unsigned)Ty->getBitWidth();
81 inline bool operator<(const IntegerValType &IVT) const {
82 return bits < IVT.bits;
86 // PointerValType - Define a class to hold the key that goes into the TypeMap
88 class PointerValType {
90 unsigned AddressSpace;
92 PointerValType(const Type *val, unsigned as) : ValTy(val), AddressSpace(as) {}
94 static PointerValType get(const PointerType *PT) {
95 return PointerValType(PT->getElementType(), PT->getAddressSpace());
98 static unsigned hashTypeStructure(const PointerType *PT) {
99 return getSubElementHash(PT);
102 bool operator<(const PointerValType &MTV) const {
103 if (AddressSpace < MTV.AddressSpace) return true;
104 return AddressSpace == MTV.AddressSpace && ValTy < MTV.ValTy;
108 //===----------------------------------------------------------------------===//
109 // Array Type Factory...
115 ArrayValType(const Type *val, uint64_t sz) : ValTy(val), Size(sz) {}
117 static ArrayValType get(const ArrayType *AT) {
118 return ArrayValType(AT->getElementType(), AT->getNumElements());
121 static unsigned hashTypeStructure(const ArrayType *AT) {
122 return (unsigned)AT->getNumElements();
125 inline bool operator<(const ArrayValType &MTV) const {
126 if (Size < MTV.Size) return true;
127 return Size == MTV.Size && ValTy < MTV.ValTy;
131 //===----------------------------------------------------------------------===//
132 // Vector Type Factory...
134 class VectorValType {
138 VectorValType(const Type *val, int sz) : ValTy(val), Size(sz) {}
140 static VectorValType get(const VectorType *PT) {
141 return VectorValType(PT->getElementType(), PT->getNumElements());
144 static unsigned hashTypeStructure(const VectorType *PT) {
145 return PT->getNumElements();
148 inline bool operator<(const VectorValType &MTV) const {
149 if (Size < MTV.Size) return true;
150 return Size == MTV.Size && ValTy < MTV.ValTy;
154 // StructValType - Define a class to hold the key that goes into the TypeMap
156 class StructValType {
157 std::vector<const Type*> ElTypes;
160 StructValType(const std::vector<const Type*> &args, bool isPacked)
161 : ElTypes(args), packed(isPacked) {}
163 static StructValType get(const StructType *ST) {
164 std::vector<const Type *> ElTypes;
165 ElTypes.reserve(ST->getNumElements());
166 for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i)
167 ElTypes.push_back(ST->getElementType(i));
169 return StructValType(ElTypes, ST->isPacked());
172 static unsigned hashTypeStructure(const StructType *ST) {
173 return ST->getNumElements();
176 inline bool operator<(const StructValType &STV) const {
177 if (ElTypes < STV.ElTypes) return true;
178 else if (ElTypes > STV.ElTypes) return false;
179 else return (int)packed < (int)STV.packed;
183 // UnionValType - Define a class to hold the key that goes into the TypeMap
186 std::vector<const Type*> ElTypes;
188 UnionValType(const Type* const* Types, unsigned NumTypes)
189 : ElTypes(&Types[0], &Types[NumTypes]) {}
191 static UnionValType get(const UnionType *UT) {
192 std::vector<const Type *> ElTypes;
193 ElTypes.reserve(UT->getNumElements());
194 for (unsigned i = 0, e = UT->getNumElements(); i != e; ++i)
195 ElTypes.push_back(UT->getElementType(i));
197 return UnionValType(&ElTypes[0], ElTypes.size());
200 static unsigned hashTypeStructure(const UnionType *UT) {
201 return UT->getNumElements();
204 inline bool operator<(const UnionValType &UTV) const {
205 return (ElTypes < UTV.ElTypes);
209 // FunctionValType - Define a class to hold the key that goes into the TypeMap
211 class FunctionValType {
213 std::vector<const Type*> ArgTypes;
216 FunctionValType(const Type *ret, const std::vector<const Type*> &args,
217 bool isVA) : RetTy(ret), ArgTypes(args), isVarArg(isVA) {}
219 static FunctionValType get(const FunctionType *FT);
221 static unsigned hashTypeStructure(const FunctionType *FT) {
222 unsigned Result = FT->getNumParams()*2 + FT->isVarArg();
226 inline bool operator<(const FunctionValType &MTV) const {
227 if (RetTy < MTV.RetTy) return true;
228 if (RetTy > MTV.RetTy) return false;
229 if (isVarArg < MTV.isVarArg) return true;
230 if (isVarArg > MTV.isVarArg) return false;
231 if (ArgTypes < MTV.ArgTypes) return true;
232 if (ArgTypes > MTV.ArgTypes) return false;
239 /// TypesByHash - Keep track of types by their structure hash value. Note
240 /// that we only keep track of types that have cycles through themselves in
243 std::multimap<unsigned, PATypeHolder> TypesByHash;
246 // PATypeHolder won't destroy non-abstract types.
247 // We can't destroy them by simply iterating, because
248 // they may contain references to each-other.
249 for (std::multimap<unsigned, PATypeHolder>::iterator I
250 = TypesByHash.begin(), E = TypesByHash.end(); I != E; ++I) {
251 Type *Ty = const_cast<Type*>(I->second.Ty);
253 // We can't invoke destroy or delete, because the type may
254 // contain references to already freed types.
255 // So we have to destruct the object the ugly way.
257 Ty->AbstractTypeUsers.clear();
258 static_cast<const Type*>(Ty)->Type::~Type();
265 void RemoveFromTypesByHash(unsigned Hash, const Type *Ty) {
266 std::multimap<unsigned, PATypeHolder>::iterator I =
267 TypesByHash.lower_bound(Hash);
268 for (; I != TypesByHash.end() && I->first == Hash; ++I) {
269 if (I->second == Ty) {
270 TypesByHash.erase(I);
275 // This must be do to an opaque type that was resolved. Switch down to hash
277 assert(Hash && "Didn't find type entry!");
278 RemoveFromTypesByHash(0, Ty);
281 /// TypeBecameConcrete - When Ty gets a notification that TheType just became
282 /// concrete, drop uses and make Ty non-abstract if we should.
283 void TypeBecameConcrete(DerivedType *Ty, const DerivedType *TheType) {
284 // If the element just became concrete, remove 'ty' from the abstract
285 // type user list for the type. Do this for as many times as Ty uses
287 for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
289 if (I->get() == TheType)
290 TheType->removeAbstractTypeUser(Ty);
292 // If the type is currently thought to be abstract, rescan all of our
293 // subtypes to see if the type has just become concrete! Note that this
294 // may send out notifications to AbstractTypeUsers that types become
296 if (Ty->isAbstract())
297 Ty->PromoteAbstractToConcrete();
301 // TypeMap - Make sure that only one instance of a particular type may be
302 // created on any given run of the compiler... note that this involves updating
303 // our map if an abstract type gets refined somehow.
305 template<class ValType, class TypeClass>
306 class TypeMap : public TypeMapBase {
307 std::map<ValType, PATypeHolder> Map;
309 typedef typename std::map<ValType, PATypeHolder>::iterator iterator;
311 inline TypeClass *get(const ValType &V) {
312 iterator I = Map.find(V);
313 return I != Map.end() ? cast<TypeClass>((Type*)I->second.get()) : 0;
316 inline void add(const ValType &V, TypeClass *Ty) {
317 Map.insert(std::make_pair(V, Ty));
319 // If this type has a cycle, remember it.
320 TypesByHash.insert(std::make_pair(ValType::hashTypeStructure(Ty), Ty));
324 /// RefineAbstractType - This method is called after we have merged a type
325 /// with another one. We must now either merge the type away with
326 /// some other type or reinstall it in the map with it's new configuration.
327 void RefineAbstractType(TypeClass *Ty, const DerivedType *OldType,
328 const Type *NewType) {
329 #ifdef DEBUG_MERGE_TYPES
330 DEBUG(dbgs() << "RefineAbstractType(" << (void*)OldType << "[" << *OldType
331 << "], " << (void*)NewType << " [" << *NewType << "])\n");
334 // Otherwise, we are changing one subelement type into another. Clearly the
335 // OldType must have been abstract, making us abstract.
336 assert(Ty->isAbstract() && "Refining a non-abstract type!");
337 assert(OldType != NewType);
339 // Make a temporary type holder for the type so that it doesn't disappear on
340 // us when we erase the entry from the map.
341 PATypeHolder TyHolder = Ty;
343 // The old record is now out-of-date, because one of the children has been
344 // updated. Remove the obsolete entry from the map.
345 unsigned NumErased = Map.erase(ValType::get(Ty));
346 assert(NumErased && "Element not found!"); NumErased = NumErased;
348 // Remember the structural hash for the type before we start hacking on it,
349 // in case we need it later.
350 unsigned OldTypeHash = ValType::hashTypeStructure(Ty);
352 // Find the type element we are refining... and change it now!
353 for (unsigned i = 0, e = Ty->getNumContainedTypes(); i != e; ++i)
354 if (Ty->ContainedTys[i] == OldType)
355 Ty->ContainedTys[i] = NewType;
356 unsigned NewTypeHash = ValType::hashTypeStructure(Ty);
358 // If there are no cycles going through this node, we can do a simple,
359 // efficient lookup in the map, instead of an inefficient nasty linear
361 if (!TypeHasCycleThroughItself(Ty)) {
362 typename std::map<ValType, PATypeHolder>::iterator I;
365 tie(I, Inserted) = Map.insert(std::make_pair(ValType::get(Ty), Ty));
367 // Refined to a different type altogether?
368 RemoveFromTypesByHash(OldTypeHash, Ty);
370 // We already have this type in the table. Get rid of the newly refined
372 TypeClass *NewTy = cast<TypeClass>((Type*)I->second.get());
373 Ty->unlockedRefineAbstractTypeTo(NewTy);
377 // Now we check to see if there is an existing entry in the table which is
378 // structurally identical to the newly refined type. If so, this type
379 // gets refined to the pre-existing type.
381 std::multimap<unsigned, PATypeHolder>::iterator I, E, Entry;
382 tie(I, E) = TypesByHash.equal_range(NewTypeHash);
384 for (; I != E; ++I) {
385 if (I->second == Ty) {
386 // Remember the position of the old type if we see it in our scan.
389 if (TypesEqual(Ty, I->second)) {
390 TypeClass *NewTy = cast<TypeClass>((Type*)I->second.get());
392 // Remove the old entry form TypesByHash. If the hash values differ
393 // now, remove it from the old place. Otherwise, continue scanning
394 // withing this hashcode to reduce work.
395 if (NewTypeHash != OldTypeHash) {
396 RemoveFromTypesByHash(OldTypeHash, Ty);
399 // Find the location of Ty in the TypesByHash structure if we
400 // haven't seen it already.
401 while (I->second != Ty) {
403 assert(I != E && "Structure doesn't contain type??");
407 TypesByHash.erase(Entry);
409 Ty->unlockedRefineAbstractTypeTo(NewTy);
415 // If there is no existing type of the same structure, we reinsert an
416 // updated record into the map.
417 Map.insert(std::make_pair(ValType::get(Ty), Ty));
420 // If the hash codes differ, update TypesByHash
421 if (NewTypeHash != OldTypeHash) {
422 RemoveFromTypesByHash(OldTypeHash, Ty);
423 TypesByHash.insert(std::make_pair(NewTypeHash, Ty));
426 // If the type is currently thought to be abstract, rescan all of our
427 // subtypes to see if the type has just become concrete! Note that this
428 // may send out notifications to AbstractTypeUsers that types become
430 if (Ty->isAbstract())
431 Ty->PromoteAbstractToConcrete();
434 void print(const char *Arg) const {
435 #ifdef DEBUG_MERGE_TYPES
436 DEBUG(dbgs() << "TypeMap<>::" << Arg << " table contents:\n");
438 for (typename std::map<ValType, PATypeHolder>::const_iterator I
439 = Map.begin(), E = Map.end(); I != E; ++I)
440 DEBUG(dbgs() << " " << (++i) << ". " << (void*)I->second.get() << " "
441 << *I->second.get() << "\n");
445 void dump() const { print("dump output"); }