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/ArrayRef.h"
19 #include "llvm/ADT/STLExtras.h"
23 //===----------------------------------------------------------------------===//
24 // Derived Type Factory Functions
25 //===----------------------------------------------------------------------===//
28 /// getSubElementHash - Generate a hash value for all of the SubType's of this
29 /// type. The hash value is guaranteed to be zero if any of the subtypes are
30 /// an opaque type. Otherwise we try to mix them in as well as possible, but do
31 /// not look at the subtype's subtype's.
32 static unsigned getSubElementHash(const Type *Ty) {
34 for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
37 const Type *SubTy = I->get();
38 HashVal += SubTy->getTypeID();
39 switch (SubTy->getTypeID()) {
41 case Type::OpaqueTyID: return 0; // Opaque -> hash = 0 no matter what.
42 case Type::IntegerTyID:
43 HashVal ^= (cast<IntegerType>(SubTy)->getBitWidth() << 3);
45 case Type::FunctionTyID:
46 HashVal ^= cast<FunctionType>(SubTy)->getNumParams()*2 +
47 cast<FunctionType>(SubTy)->isVarArg();
50 HashVal ^= cast<ArrayType>(SubTy)->getNumElements();
52 case Type::VectorTyID:
53 HashVal ^= cast<VectorType>(SubTy)->getNumElements();
55 case Type::StructTyID:
56 HashVal ^= cast<StructType>(SubTy)->getNumElements();
58 case Type::PointerTyID:
59 HashVal ^= cast<PointerType>(SubTy)->getAddressSpace();
63 return HashVal ? HashVal : 1; // Do not return zero unless opaque subty.
66 //===----------------------------------------------------------------------===//
67 // Integer Type Factory...
69 class IntegerValType {
72 IntegerValType(uint32_t numbits) : bits(numbits) {}
74 static IntegerValType get(const IntegerType *Ty) {
75 return IntegerValType(Ty->getBitWidth());
78 static unsigned hashTypeStructure(const IntegerType *Ty) {
79 return (unsigned)Ty->getBitWidth();
82 inline bool operator<(const IntegerValType &IVT) const {
83 return bits < IVT.bits;
87 // PointerValType - Define a class to hold the key that goes into the TypeMap
89 class PointerValType {
91 unsigned AddressSpace;
93 PointerValType(const Type *val, unsigned as) : ValTy(val), AddressSpace(as) {}
95 static PointerValType get(const PointerType *PT) {
96 return PointerValType(PT->getElementType(), PT->getAddressSpace());
99 static unsigned hashTypeStructure(const PointerType *PT) {
100 return getSubElementHash(PT);
103 bool operator<(const PointerValType &MTV) const {
104 if (AddressSpace < MTV.AddressSpace) return true;
105 return AddressSpace == MTV.AddressSpace && ValTy < MTV.ValTy;
109 //===----------------------------------------------------------------------===//
110 // Array Type Factory...
116 ArrayValType(const Type *val, uint64_t sz) : ValTy(val), Size(sz) {}
118 static ArrayValType get(const ArrayType *AT) {
119 return ArrayValType(AT->getElementType(), AT->getNumElements());
122 static unsigned hashTypeStructure(const ArrayType *AT) {
123 return (unsigned)AT->getNumElements();
126 inline bool operator<(const ArrayValType &MTV) const {
127 if (Size < MTV.Size) return true;
128 return Size == MTV.Size && ValTy < MTV.ValTy;
132 //===----------------------------------------------------------------------===//
133 // Vector Type Factory...
135 class VectorValType {
139 VectorValType(const Type *val, int sz) : ValTy(val), Size(sz) {}
141 static VectorValType get(const VectorType *PT) {
142 return VectorValType(PT->getElementType(), PT->getNumElements());
145 static unsigned hashTypeStructure(const VectorType *PT) {
146 return PT->getNumElements();
149 inline bool operator<(const VectorValType &MTV) const {
150 if (Size < MTV.Size) return true;
151 return Size == MTV.Size && ValTy < MTV.ValTy;
155 // StructValType - Define a class to hold the key that goes into the TypeMap
157 class StructValType {
158 std::vector<const Type*> ElTypes;
161 StructValType(ArrayRef<const Type*> args, bool isPacked)
162 : ElTypes(args.vec()), packed(isPacked) {}
164 static StructValType get(const StructType *ST) {
165 std::vector<const Type *> ElTypes;
166 ElTypes.reserve(ST->getNumElements());
167 for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i)
168 ElTypes.push_back(ST->getElementType(i));
170 return StructValType(ElTypes, ST->isPacked());
173 static unsigned hashTypeStructure(const StructType *ST) {
174 return ST->getNumElements();
177 inline bool operator<(const StructValType &STV) const {
178 if (ElTypes < STV.ElTypes) return true;
179 else if (ElTypes > STV.ElTypes) return false;
180 else return (int)packed < (int)STV.packed;
184 // FunctionValType - Define a class to hold the key that goes into the TypeMap
186 class FunctionValType {
188 std::vector<const Type*> ArgTypes;
191 FunctionValType(const Type *ret, ArrayRef<const Type*> args, bool isVA)
192 : RetTy(ret), ArgTypes(args.vec()), isVarArg(isVA) {}
194 static FunctionValType get(const FunctionType *FT);
196 static unsigned hashTypeStructure(const FunctionType *FT) {
197 unsigned Result = FT->getNumParams()*2 + FT->isVarArg();
201 inline bool operator<(const FunctionValType &MTV) const {
202 if (RetTy < MTV.RetTy) return true;
203 if (RetTy > MTV.RetTy) return false;
204 if (isVarArg < MTV.isVarArg) return true;
205 if (isVarArg > MTV.isVarArg) return false;
206 if (ArgTypes < MTV.ArgTypes) return true;
207 if (ArgTypes > MTV.ArgTypes) return false;
214 /// TypesByHash - Keep track of types by their structure hash value. Note
215 /// that we only keep track of types that have cycles through themselves in
218 std::multimap<unsigned, PATypeHolder> TypesByHash;
221 // PATypeHolder won't destroy non-abstract types.
222 // We can't destroy them by simply iterating, because
223 // they may contain references to each-other.
224 for (std::multimap<unsigned, PATypeHolder>::iterator I
225 = TypesByHash.begin(), E = TypesByHash.end(); I != E; ++I) {
226 Type *Ty = const_cast<Type*>(I->second.Ty);
228 // We can't invoke destroy or delete, because the type may
229 // contain references to already freed types.
230 // So we have to destruct the object the ugly way.
232 Ty->AbstractTypeUsers.clear();
233 static_cast<const Type*>(Ty)->Type::~Type();
240 void RemoveFromTypesByHash(unsigned Hash, const Type *Ty) {
241 std::multimap<unsigned, PATypeHolder>::iterator I =
242 TypesByHash.lower_bound(Hash);
243 for (; I != TypesByHash.end() && I->first == Hash; ++I) {
244 if (I->second == Ty) {
245 TypesByHash.erase(I);
250 // This must be do to an opaque type that was resolved. Switch down to hash
252 assert(Hash && "Didn't find type entry!");
253 RemoveFromTypesByHash(0, Ty);
256 /// TypeBecameConcrete - When Ty gets a notification that TheType just became
257 /// concrete, drop uses and make Ty non-abstract if we should.
258 void TypeBecameConcrete(DerivedType *Ty, const DerivedType *TheType) {
259 // If the element just became concrete, remove 'ty' from the abstract
260 // type user list for the type. Do this for as many times as Ty uses
262 for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
264 if (I->get() == TheType)
265 TheType->removeAbstractTypeUser(Ty);
267 // If the type is currently thought to be abstract, rescan all of our
268 // subtypes to see if the type has just become concrete! Note that this
269 // may send out notifications to AbstractTypeUsers that types become
271 if (Ty->isAbstract())
272 Ty->PromoteAbstractToConcrete();
276 // TypeMap - Make sure that only one instance of a particular type may be
277 // created on any given run of the compiler... note that this involves updating
278 // our map if an abstract type gets refined somehow.
280 template<class ValType, class TypeClass>
281 class TypeMap : public TypeMapBase {
282 std::map<ValType, PATypeHolder> Map;
284 typedef typename std::map<ValType, PATypeHolder>::iterator iterator;
286 inline TypeClass *get(const ValType &V) {
287 iterator I = Map.find(V);
288 return I != Map.end() ? cast<TypeClass>((Type*)I->second.get()) : 0;
291 inline void add(const ValType &V, TypeClass *Ty) {
292 Map.insert(std::make_pair(V, Ty));
294 // If this type has a cycle, remember it.
295 TypesByHash.insert(std::make_pair(ValType::hashTypeStructure(Ty), Ty));
299 /// RefineAbstractType - This method is called after we have merged a type
300 /// with another one. We must now either merge the type away with
301 /// some other type or reinstall it in the map with it's new configuration.
302 void RefineAbstractType(TypeClass *Ty, const DerivedType *OldType,
303 const Type *NewType) {
304 #ifdef DEBUG_MERGE_TYPES
305 DEBUG(dbgs() << "RefineAbstractType(" << (void*)OldType << "[" << *OldType
306 << "], " << (void*)NewType << " [" << *NewType << "])\n");
309 // Otherwise, we are changing one subelement type into another. Clearly the
310 // OldType must have been abstract, making us abstract.
311 assert(Ty->isAbstract() && "Refining a non-abstract type!");
312 assert(OldType != NewType);
314 // Make a temporary type holder for the type so that it doesn't disappear on
315 // us when we erase the entry from the map.
316 PATypeHolder TyHolder = Ty;
318 // The old record is now out-of-date, because one of the children has been
319 // updated. Remove the obsolete entry from the map.
320 unsigned NumErased = Map.erase(ValType::get(Ty));
321 assert(NumErased && "Element not found!"); (void)NumErased;
323 // Remember the structural hash for the type before we start hacking on it,
324 // in case we need it later.
325 unsigned OldTypeHash = ValType::hashTypeStructure(Ty);
327 // Find the type element we are refining... and change it now!
328 for (unsigned i = 0, e = Ty->getNumContainedTypes(); i != e; ++i)
329 if (Ty->ContainedTys[i] == OldType)
330 Ty->ContainedTys[i] = NewType;
331 unsigned NewTypeHash = ValType::hashTypeStructure(Ty);
333 // If there are no cycles going through this node, we can do a simple,
334 // efficient lookup in the map, instead of an inefficient nasty linear
336 if (!TypeHasCycleThroughItself(Ty)) {
337 typename std::map<ValType, PATypeHolder>::iterator I;
340 tie(I, Inserted) = Map.insert(std::make_pair(ValType::get(Ty), Ty));
342 // Refined to a different type altogether?
343 RemoveFromTypesByHash(OldTypeHash, Ty);
345 // We already have this type in the table. Get rid of the newly refined
347 TypeClass *NewTy = cast<TypeClass>((Type*)I->second.get());
348 Ty->refineAbstractTypeTo(NewTy);
352 // Now we check to see if there is an existing entry in the table which is
353 // structurally identical to the newly refined type. If so, this type
354 // gets refined to the pre-existing type.
356 std::multimap<unsigned, PATypeHolder>::iterator I, E, Entry;
357 tie(I, E) = TypesByHash.equal_range(NewTypeHash);
359 for (; I != E; ++I) {
360 if (I->second == Ty) {
361 // Remember the position of the old type if we see it in our scan.
366 if (!TypesEqual(Ty, I->second))
369 TypeClass *NewTy = cast<TypeClass>((Type*)I->second.get());
371 // Remove the old entry form TypesByHash. If the hash values differ
372 // now, remove it from the old place. Otherwise, continue scanning
373 // withing this hashcode to reduce work.
374 if (NewTypeHash != OldTypeHash) {
375 RemoveFromTypesByHash(OldTypeHash, Ty);
378 // Find the location of Ty in the TypesByHash structure if we
379 // haven't seen it already.
380 while (I->second != Ty) {
382 assert(I != E && "Structure doesn't contain type??");
386 TypesByHash.erase(Entry);
388 Ty->refineAbstractTypeTo(NewTy);
392 // If there is no existing type of the same structure, we reinsert an
393 // updated record into the map.
394 Map.insert(std::make_pair(ValType::get(Ty), Ty));
397 // If the hash codes differ, update TypesByHash
398 if (NewTypeHash != OldTypeHash) {
399 RemoveFromTypesByHash(OldTypeHash, Ty);
400 TypesByHash.insert(std::make_pair(NewTypeHash, Ty));
403 // If the type is currently thought to be abstract, rescan all of our
404 // subtypes to see if the type has just become concrete! Note that this
405 // may send out notifications to AbstractTypeUsers that types become
407 if (Ty->isAbstract())
408 Ty->PromoteAbstractToConcrete();
411 void print(const char *Arg) const {
412 #ifdef DEBUG_MERGE_TYPES
413 DEBUG(dbgs() << "TypeMap<>::" << Arg << " table contents:\n");
415 for (typename std::map<ValType, PATypeHolder>::const_iterator I
416 = Map.begin(), E = Map.end(); I != E; ++I)
417 DEBUG(dbgs() << " " << (++i) << ". " << (void*)I->second.get() << " "
418 << *I->second.get() << "\n");
422 void dump() const { print("dump output"); }