//===- llvm/Analysis/AliasSetTracker.h - Build Alias Sets -------*- C++ -*-===//
//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
// This file defines two classes: AliasSetTracker and AliasSet. These interface
// are used to classify a collection of pointer references into a maximal number
// of disjoint sets. Each AliasSet object constructed by the AliasSetTracker
// object refers to memory disjoint from the other sets.
-//
+//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_ALIASSETTRACKER_H
#define LLVM_ANALYSIS_ALIASSETTRACKER_H
#include "llvm/Support/CallSite.h"
-#include "Support/iterator"
-#include "Support/hash_map"
-#include "Support/ilist"
+#include "llvm/Support/Streams.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/hash_map.h"
+#include "llvm/ADT/ilist.h"
+
+namespace llvm {
+
class AliasAnalysis;
class LoadInst;
class StoreInst;
+class FreeInst;
+class VAArgInst;
class AliasSetTracker;
class AliasSet;
class AliasSet {
friend class AliasSetTracker;
- struct PointerRec;
+ class PointerRec;
typedef std::pair<Value* const, PointerRec> HashNodePair;
class PointerRec {
- HashNodePair *NextInList;
+ HashNodePair **PrevInList, *NextInList;
AliasSet *AS;
unsigned Size;
public:
- PointerRec() : NextInList(0), AS(0), Size(0) {}
+ PointerRec() : PrevInList(0), NextInList(0), AS(0), Size(0) {}
HashNodePair *getNext() const { return NextInList; }
bool hasAliasSet() const { return AS != 0; }
+ HashNodePair** setPrevInList(HashNodePair **PIL) {
+ PrevInList = PIL;
+ return &NextInList;
+ }
+
void updateSize(unsigned NewSize) {
if (NewSize > Size) Size = NewSize;
}
unsigned getSize() const { return Size; }
- AliasSet *getAliasSet(AliasSetTracker &AST) {
+ AliasSet *getAliasSet(AliasSetTracker &AST) {
assert(AS && "No AliasSet yet!");
if (AS->Forward) {
AliasSet *OldAS = AS;
AS = OldAS->getForwardedTarget(AST);
- if (--OldAS->RefCount == 0)
- OldAS->removeFromTracker(AST);
- AS->RefCount++;
+ AS->addRef();
+ OldAS->dropRef(AST);
}
return AS;
}
assert(AS == 0 && "Already have an alias set!");
AS = as;
}
- void setTail(HashNodePair *T) {
- assert(NextInList == 0 && "Already have tail!");
- NextInList = T;
+
+ void removeFromList() {
+ if (NextInList) NextInList->second.PrevInList = PrevInList;
+ *PrevInList = NextInList;
+ if (AS->PtrListEnd == &NextInList) {
+ AS->PtrListEnd = PrevInList;
+ assert(*AS->PtrListEnd == 0 && "List not terminated right!");
+ }
}
};
- HashNodePair *PtrListHead, *PtrListTail; // Singly linked list of nodes
+ HashNodePair *PtrList, **PtrListEnd; // Doubly linked list of nodes
AliasSet *Forward; // Forwarding pointer
AliasSet *Next, *Prev; // Doubly linked list of AliasSets
// RefCount - Number of nodes pointing to this AliasSet plus the number of
// AliasSets forwarding to it.
- unsigned RefCount : 29;
+ unsigned RefCount : 28;
/// AccessType - Keep track of whether this alias set merely refers to the
/// locations of memory, whether it modifies the memory, or whether it does
/// both. The lattice goes from "NoModRef" to either Refs or Mods, then to
- /// ModRef as neccesary.
+ /// ModRef as necessary.
///
enum AccessType {
NoModRef = 0, Refs = 1, // Ref = bit 1
};
unsigned AliasTy : 1;
+ // Volatile - True if this alias set contains volatile loads or stores.
+ bool Volatile : 1;
+
+ friend struct ilist_traits<AliasSet>;
+ AliasSet *getPrev() const { return Prev; }
+ AliasSet *getNext() const { return Next; }
+ void setPrev(AliasSet *P) { Prev = P; }
+ void setNext(AliasSet *N) { Next = N; }
+
+ void addRef() { ++RefCount; }
+ void dropRef(AliasSetTracker &AST) {
+ assert(RefCount >= 1 && "Invalid reference count detected!");
+ if (--RefCount == 0)
+ removeFromTracker(AST);
+ }
+
+public:
+ /// Accessors...
+ bool isRef() const { return AccessTy & Refs; }
+ bool isMod() const { return AccessTy & Mods; }
+ bool isMustAlias() const { return AliasTy == MustAlias; }
+ bool isMayAlias() const { return AliasTy == MayAlias; }
+
+ // isVolatile - Return true if this alias set contains volatile loads or
+ // stores.
+ bool isVolatile() const { return Volatile; }
+
+ /// isForwardingAliasSet - Return true if this alias set should be ignored as
+ /// part of the AliasSetTracker object.
+ bool isForwardingAliasSet() const { return Forward; }
+
+ /// mergeSetIn - Merge the specified alias set into this alias set...
+ ///
+ void mergeSetIn(AliasSet &AS, AliasSetTracker &AST);
+
+ // Alias Set iteration - Allow access to all of the pointer which are part of
+ // this alias set...
+ class iterator;
+ iterator begin() const { return iterator(PtrList); }
+ iterator end() const { return iterator(); }
+ bool empty() const { return PtrList == 0; }
+
+ void print(std::ostream &OS) const;
+ void print(std::ostream *OS) const { if (OS) print(*OS); }
+ void dump() const;
+
/// Define an iterator for alias sets... this is just a forward iterator.
class iterator : public forward_iterator<HashNodePair, ptrdiff_t> {
HashNodePair *CurNode;
public:
- iterator(HashNodePair *CN = 0) : CurNode(CN) {}
-
+ explicit iterator(HashNodePair *CN = 0) : CurNode(CN) {}
+
bool operator==(const iterator& x) const {
return CurNode == x.CurNode;
}
CurNode = I.CurNode;
return *this;
}
-
+
value_type &operator*() const {
assert(CurNode && "Dereferencing AliasSet.end()!");
return *CurNode;
}
value_type *operator->() const { return &operator*(); }
-
+
+ Value *getPointer() const { return CurNode->first; }
+ unsigned getSize() const { return CurNode->second.getSize(); }
+
iterator& operator++() { // Preincrement
assert(CurNode && "Advancing past AliasSet.end()!");
CurNode = CurNode->second.getNext();
return *this;
}
iterator operator++(int) { // Postincrement
- iterator tmp = *this; ++*this; return tmp;
+ iterator tmp = *this; ++*this; return tmp;
}
};
- friend class ilist_traits<AliasSet>;
- AliasSet *getPrev() const { return Prev; }
- AliasSet *getNext() const { return Next; }
- void setPrev(AliasSet *P) { Prev = P; }
- void setNext(AliasSet *N) { Next = N; }
-
-public:
- /// Accessors...
- bool isRef() const { return AccessTy & Refs; }
- bool isMod() const { return AccessTy & Mods; }
- bool isMustAlias() const { return AliasTy == MustAlias; }
- bool isMayAlias() const { return AliasTy == MayAlias; }
-
- /// mergeSetIn - Merge the specified alias set into this alias set...
- ///
- void mergeSetIn(AliasSet &AS);
-
- // Alias Set iteration - Allow access to all of the pointer which are part of
- // this alias set...
- iterator begin() const { return iterator(PtrListHead); }
- iterator end() const { return iterator(); }
-
- void print(std::ostream &OS) const;
- void dump() const;
-
private:
// Can only be created by AliasSetTracker
- AliasSet() : PtrListHead(0), PtrListTail(0), Forward(0), RefCount(0),
- AccessTy(NoModRef), AliasTy(MustAlias) {
+ AliasSet() : PtrList(0), PtrListEnd(&PtrList), Forward(0), RefCount(0),
+ AccessTy(NoModRef), AliasTy(MustAlias), Volatile(false) {
+ }
+
+ AliasSet(const AliasSet &AS) {
+ assert(0 && "Copy ctor called!?!?!");
+ abort();
}
+
HashNodePair *getSomePointer() const {
- return PtrListHead ? PtrListHead : 0;
+ return PtrList;
}
/// getForwardedTarget - Return the real alias set this represents. If this
AliasSet *Dest = Forward->getForwardedTarget(AST);
if (Dest != Forward) {
- Dest->RefCount++;
- if (--Forward->RefCount == 0)
- Forward->removeFromTracker(AST);
+ Dest->addRef();
+ Forward->dropRef(AST);
Forward = Dest;
}
return Dest;
void removeFromTracker(AliasSetTracker &AST);
- void addPointer(AliasSetTracker &AST, HashNodePair &Entry, unsigned Size);
- void addCallSite(CallSite CS);
+ void addPointer(AliasSetTracker &AST, HashNodePair &Entry, unsigned Size,
+ bool KnownMustAlias = false);
+ void addCallSite(CallSite CS, AliasAnalysis &AA);
+ void removeCallSite(CallSite CS) {
+ for (size_t i = 0, e = CallSites.size(); i != e; ++i)
+ if (CallSites[i].getInstruction() == CS.getInstruction()) {
+ CallSites[i] = CallSites.back();
+ CallSites.pop_back();
+ }
+ }
+ void setVolatile() { Volatile = true; }
/// aliasesPointer - Return true if the specified pointer "may" (or must)
/// alias one of the members in the set.
/// AliasSetTracker ctor - Create an empty collection of AliasSets, and use
/// the specified alias analysis object to disambiguate load and store
/// addresses.
- AliasSetTracker(AliasAnalysis &aa) : AA(aa) {}
+ explicit AliasSetTracker(AliasAnalysis &aa) : AA(aa) {}
+ ~AliasSetTracker() { clear(); }
/// add methods - These methods are used to add different types of
/// instructions to the alias sets. Adding a new instruction can result in
/// 3. If the instruction aliases multiple sets, merge the sets, and add
/// the instruction to the result.
///
- void add(LoadInst *LI);
- void add(StoreInst *SI);
- void add(CallSite CS); // Call/Invoke instructions
- void add(CallInst *CI) { add(CallSite(CI)); }
- void add(InvokeInst *II) { add(CallSite(II)); }
- void add(Instruction *I); // Dispatch to one of the other add methods...
+ /// These methods return true if inserting the instruction resulted in the
+ /// addition of a new alias set (i.e., the pointer did not alias anything).
+ ///
+ bool add(Value *Ptr, unsigned Size); // Add a location
+ bool add(LoadInst *LI);
+ bool add(StoreInst *SI);
+ bool add(FreeInst *FI);
+ bool add(VAArgInst *VAAI);
+ bool add(CallSite CS); // Call/Invoke instructions
+ bool add(CallInst *CI) { return add(CallSite(CI)); }
+ bool add(InvokeInst *II) { return add(CallSite(II)); }
+ bool add(Instruction *I); // Dispatch to one of the other add methods...
+ void add(BasicBlock &BB); // Add all instructions in basic block
+ void add(const AliasSetTracker &AST); // Add alias relations from another AST
+
+ /// remove methods - These methods are used to remove all entries that might
+ /// be aliased by the specified instruction. These methods return true if any
+ /// alias sets were eliminated.
+ bool remove(Value *Ptr, unsigned Size); // Remove a location
+ bool remove(LoadInst *LI);
+ bool remove(StoreInst *SI);
+ bool remove(FreeInst *FI);
+ bool remove(VAArgInst *VAAI);
+ bool remove(CallSite CS);
+ bool remove(CallInst *CI) { return remove(CallSite(CI)); }
+ bool remove(InvokeInst *II) { return remove(CallSite(II)); }
+ bool remove(Instruction *I);
+ void remove(AliasSet &AS);
+
+ void clear() {
+ PointerMap.clear();
+ AliasSets.clear();
+ }
/// getAliasSets - Return the alias sets that are active.
+ ///
const ilist<AliasSet> &getAliasSets() const { return AliasSets; }
/// getAliasSetForPointer - Return the alias set that the specified pointer
- /// lives in...
- AliasSet &getAliasSetForPointer(Value *P, unsigned Size);
+ /// lives in. If the New argument is non-null, this method sets the value to
+ /// true if a new alias set is created to contain the pointer (because the
+ /// pointer didn't alias anything).
+ AliasSet &getAliasSetForPointer(Value *P, unsigned Size, bool *New = 0);
+
+ /// getAliasSetForPointerIfExists - Return the alias set containing the
+ /// location specified if one exists, otherwise return null.
+ AliasSet *getAliasSetForPointerIfExists(Value *P, unsigned Size) {
+ return findAliasSetForPointer(P, Size);
+ }
+
+ /// containsPointer - Return true if the specified location is represented by
+ /// this alias set, false otherwise. This does not modify the AST object or
+ /// alias sets.
+ bool containsPointer(Value *P, unsigned Size) const;
/// getAliasAnalysis - Return the underlying alias analysis object used by
/// this tracker.
AliasAnalysis &getAliasAnalysis() const { return AA; }
+ /// deleteValue method - This method is used to remove a pointer value from
+ /// the AliasSetTracker entirely. It should be used when an instruction is
+ /// deleted from the program to update the AST. If you don't use this, you
+ /// would have dangling pointers to deleted instructions.
+ ///
+ void deleteValue(Value *PtrVal);
+
+ /// copyValue - This method should be used whenever a preexisting value in the
+ /// program is copied or cloned, introducing a new value. Note that it is ok
+ /// for clients that use this method to introduce the same value multiple
+ /// times: if the tracker already knows about a value, it will ignore the
+ /// request.
+ ///
+ void copyValue(Value *From, Value *To);
+
+
typedef ilist<AliasSet>::iterator iterator;
typedef ilist<AliasSet>::const_iterator const_iterator;
iterator end() { return AliasSets.end(); }
void print(std::ostream &OS) const;
+ void print(std::ostream *OS) const { if (OS) print(*OS); }
void dump() const;
private:
AliasSet::PointerRec())).first;
}
- void addPointer(Value *P, unsigned Size, AliasSet::AccessType E) {
- AliasSet &AS = getAliasSetForPointer(P, Size);
+ AliasSet &addPointer(Value *P, unsigned Size, AliasSet::AccessType E,
+ bool &NewSet) {
+ NewSet = false;
+ AliasSet &AS = getAliasSetForPointer(P, Size, &NewSet);
AS.AccessTy |= E;
+ return AS;
}
AliasSet *findAliasSetForPointer(const Value *Ptr, unsigned Size);
return OS;
}
+} // End llvm namespace
+
#endif
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