#include "llvm/Analysis/AliasSetTracker.h"
#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/iMemory.h"
-#include "llvm/iOther.h"
-#include "llvm/iTerminators.h"
+#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Assembly/Writer.h"
AS.CallSites.clear();
}
- // FIXME: If AS's refcount is zero, nuke it now...
- assert(RefCount != 0);
-
AS.Forward = this; // Forward across AS now...
- RefCount++; // AS is now pointing to us...
+ addRef(); // AS is now pointing to us...
// Merge the list of constituent pointers...
if (AS.PtrList) {
AS.PtrList = 0;
AS.PtrListEnd = &AS.PtrList;
+ assert(*AS.PtrListEnd == 0 && "End of list is not null?");
}
}
void AliasSetTracker::removeAliasSet(AliasSet *AS) {
+ if (AliasSet *Fwd = AS->Forward) {
+ Fwd->dropRef(*this);
+ AS->Forward = 0;
+ }
AliasSets.erase(AS);
}
}
void AliasSet::addPointer(AliasSetTracker &AST, HashNodePair &Entry,
- unsigned Size) {
+ unsigned Size, bool KnownMustAlias) {
assert(!Entry.second.hasAliasSet() && "Entry already in set!");
- AliasAnalysis &AA = AST.getAliasAnalysis();
-
- if (isMustAlias()) // Check to see if we have to downgrade to _may_ alias
+ // Check to see if we have to downgrade to _may_ alias.
+ if (isMustAlias() && !KnownMustAlias)
if (HashNodePair *P = getSomePointer()) {
+ AliasAnalysis &AA = AST.getAliasAnalysis();
AliasAnalysis::AliasResult Result =
AA.alias(P->first, P->second.getSize(), Entry.first, Size);
if (Result == AliasAnalysis::MayAlias)
assert(*PtrListEnd == 0 && "End of list is not null?");
*PtrListEnd = &Entry;
PtrListEnd = Entry.second.setPrevInList(PtrListEnd);
- RefCount++; // Entry points to alias set...
+ assert(*PtrListEnd == 0 && "End of list is not null?");
+ addRef(); // Entry points to alias set...
}
void AliasSet::addCallSite(CallSite CS, AliasAnalysis &AA) {
// If this is a may-alias set, we have to check all of the pointers in the set
// to be sure it doesn't alias the set...
for (iterator I = begin(), E = end(); I != E; ++I)
- if (AA.alias(Ptr, Size, I->first, I->second.getSize()))
+ if (AA.alias(Ptr, Size, I.getPointer(), I.getSize()))
return true;
// Check the call sites list and invoke list...
- if (!CallSites.empty())
- // FIXME: this is pessimistic!
- return true;
+ if (!CallSites.empty()) {
+ if (AA.hasNoModRefInfoForCalls())
+ return true;
+
+ for (unsigned i = 0, e = CallSites.size(); i != e; ++i)
+ if (AA.getModRefInfo(CallSites[i], const_cast<Value*>(Ptr), Size)
+ != AliasAnalysis::NoModRef)
+ return true;
+ }
return false;
}
bool AliasSet::aliasesCallSite(CallSite CS, AliasAnalysis &AA) const {
- // FIXME: Use mod/ref information to prune this better!
if (Function *F = CS.getCalledFunction())
if (AA.doesNotAccessMemory(F))
return false;
- return true;
+ if (AA.hasNoModRefInfoForCalls())
+ return true;
+
+ for (unsigned i = 0, e = CallSites.size(); i != e; ++i)
+ if (AA.getModRefInfo(CallSites[i], CS) != AliasAnalysis::NoModRef ||
+ AA.getModRefInfo(CS, CallSites[i]) != AliasAnalysis::NoModRef)
+ return true;
+
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ if (AA.getModRefInfo(CS, I.getPointer(), I.getSize()) !=
+ AliasAnalysis::NoModRef)
+ return true;
+
+ return false;
}
AliasSet::HashNodePair &Entry = getEntryFor(Pointer);
// Check to see if the pointer is already known...
- if (Entry.second.hasAliasSet() && Size <= Entry.second.getSize()) {
+ if (Entry.second.hasAliasSet()) {
+ Entry.second.updateSize(Size);
// Return the set!
return *Entry.second.getAliasSet(*this)->getForwardedTarget(*this);
} else if (AliasSet *AS = findAliasSetForPointer(Pointer, Size)) {
} else {
if (New) *New = true;
// Otherwise create a new alias set to hold the loaded pointer...
- AliasSets.push_back(AliasSet());
+ AliasSets.push_back(new AliasSet());
AliasSets.back().addPointer(*this, Entry, Size);
return AliasSets.back();
}
}
+bool AliasSetTracker::add(Value *Ptr, unsigned Size) {
+ bool NewPtr;
+ addPointer(Ptr, Size, AliasSet::NoModRef, NewPtr);
+ return NewPtr;
+}
+
+
bool AliasSetTracker::add(LoadInst *LI) {
bool NewPtr;
AliasSet &AS = addPointer(LI->getOperand(0),
return NewPtr;
}
+bool AliasSetTracker::add(FreeInst *FI) {
+ bool NewPtr;
+ AliasSet &AS = addPointer(FI->getOperand(0), ~0,
+ AliasSet::Mods, NewPtr);
+ return NewPtr;
+}
+
bool AliasSetTracker::add(CallSite CS) {
- bool NewPtr;
if (Function *F = CS.getCalledFunction())
if (AA.doesNotAccessMemory(F))
return true; // doesn't alias anything
AliasSet *AS = findAliasSetForCallSite(CS);
if (!AS) {
- AliasSets.push_back(AliasSet());
+ AliasSets.push_back(new AliasSet());
AS = &AliasSets.back();
AS->addCallSite(CS, AA);
return true;
return add(CI);
else if (InvokeInst *II = dyn_cast<InvokeInst>(I))
return add(II);
+ else if (FreeInst *FI = dyn_cast<FreeInst>(I))
+ return add(FI);
return true;
}
AliasSet::iterator I = AS.begin(), E = AS.end();
bool X;
for (; I != E; ++I)
- addPointer(I->first, I->second.getSize(),
+ addPointer(I.getPointer(), I.getSize(),
(AliasSet::AccessType)AS.AccessTy, X);
}
}
+/// remove - Remove the specified (potentially non-empty) alias set from the
+/// tracker.
+void AliasSetTracker::remove(AliasSet &AS) {
+ bool SetDead;
+ do {
+ AliasSet::iterator I = AS.begin();
+ Value *Ptr = I.getPointer(); ++I;
+
+ // deleteValue will delete the set automatically when the last pointer
+ // reference is destroyed. "Predict" when this will happen.
+ SetDead = I == AS.end();
+ deleteValue(Ptr); // Delete all of the pointers from the set
+ } while (!SetDead);
+}
+
+bool AliasSetTracker::remove(Value *Ptr, unsigned Size) {
+ AliasSet *AS = findAliasSetForPointer(Ptr, Size);
+ if (!AS) return false;
+ remove(*AS);
+ return true;
+}
+
+bool AliasSetTracker::remove(LoadInst *LI) {
+ unsigned Size = AA.getTargetData().getTypeSize(LI->getType());
+ AliasSet *AS = findAliasSetForPointer(LI->getOperand(0), Size);
+ if (!AS) return false;
+ remove(*AS);
+ return true;
+}
+
+bool AliasSetTracker::remove(StoreInst *SI) {
+ unsigned Size = AA.getTargetData().getTypeSize(SI->getOperand(0)->getType());
+ AliasSet *AS = findAliasSetForPointer(SI->getOperand(1), Size);
+ if (!AS) return false;
+ remove(*AS);
+ return true;
+}
+
+bool AliasSetTracker::remove(FreeInst *FI) {
+ AliasSet *AS = findAliasSetForPointer(FI->getOperand(0), ~0);
+ if (!AS) return false;
+ remove(*AS);
+ return true;
+}
+
+bool AliasSetTracker::remove(CallSite CS) {
+ if (Function *F = CS.getCalledFunction())
+ if (AA.doesNotAccessMemory(F))
+ return false; // doesn't alias anything
+
+ AliasSet *AS = findAliasSetForCallSite(CS);
+ if (!AS) return false;
+ remove(*AS);
+ return true;
+}
+
+bool AliasSetTracker::remove(Instruction *I) {
+ // Dispatch to one of the other remove methods...
+ if (LoadInst *LI = dyn_cast<LoadInst>(I))
+ return remove(LI);
+ else if (StoreInst *SI = dyn_cast<StoreInst>(I))
+ return remove(SI);
+ else if (CallInst *CI = dyn_cast<CallInst>(I))
+ return remove(CI);
+ else if (FreeInst *FI = dyn_cast<FreeInst>(I))
+ return remove(FI);
+ return true;
+}
+
// deleteValue method - This method is used to remove a pointer value from the
// AliasSetTracker entirely. It should be used when an instruction is deleted
// dangling pointers to deleted instructions.
//
void AliasSetTracker::deleteValue(Value *PtrVal) {
- // First, look up the PointerRec for this pointer...
+ // Notify the alias analysis implementation that this value is gone.
+ AA.deleteValue(PtrVal);
+
+ // First, look up the PointerRec for this pointer.
hash_map<Value*, AliasSet::PointerRec>::iterator I = PointerMap.find(PtrVal);
if (I == PointerMap.end()) return; // Noop
// Unlink from the list of values...
PtrValEnt.second.removeFromList();
// Stop using the alias set
- if (--AS->RefCount == 0)
- AS->removeFromTracker(*this);
-
+ AS->dropRef(*this);
PointerMap.erase(I);
}
+// 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 AliasSetTracker::copyValue(Value *From, Value *To) {
+ // Notify the alias analysis implementation that this value is copied.
+ AA.copyValue(From, To);
+
+ // First, look up the PointerRec for this pointer.
+ hash_map<Value*, AliasSet::PointerRec>::iterator I = PointerMap.find(From);
+ if (I == PointerMap.end() || !I->second.hasAliasSet())
+ return; // Noop
+
+ AliasSet::HashNodePair &Entry = getEntryFor(To);
+ if (Entry.second.hasAliasSet()) return; // Already in the tracker!
+
+ // Add it to the alias set it aliases...
+ AliasSet *AS = I->second.getAliasSet(*this);
+ AS->addPointer(*this, Entry, I->second.getSize(), true);
+}
+
+
//===----------------------------------------------------------------------===//
// AliasSet/AliasSetTracker Printing Support
OS << "Pointers: ";
for (iterator I = begin(), E = end(); I != E; ++I) {
if (I != begin()) OS << ", ";
- WriteAsOperand(OS << "(", I->first);
- OS << ", " << I->second.getSize() << ")";
+ WriteAsOperand(OS << "(", I.getPointer());
+ OS << ", " << I.getSize() << ")";
}
}
if (!CallSites.empty()) {
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