//===- AliasSetTracker.cpp - Alias Sets Tracker implementation-------------===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
// This file implements the AliasSetTracker and AliasSet classes.
-//
+//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/AliasSetTracker.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
+#include "llvm/Type.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Assembly/Writer.h"
+#include "llvm/Support/Compiler.h"
#include "llvm/Support/InstIterator.h"
-#include <iostream>
+#include "llvm/Support/Streams.h"
using namespace llvm;
-/// mergeSetIn - Merge the specified alias set into this alias set...
+/// mergeSetIn - Merge the specified alias set into this alias set.
///
-void AliasSet::mergeSetIn(AliasSet &AS) {
+void AliasSet::mergeSetIn(AliasSet &AS, AliasSetTracker &AST) {
assert(!AS.Forward && "Alias set is already forwarding!");
assert(!Forward && "This set is a forwarding set!!");
AccessTy |= AS.AccessTy;
AliasTy |= AS.AliasTy;
+ if (AliasTy == MustAlias) {
+ // Check that these two merged sets really are must aliases. Since both
+ // used to be must-alias sets, we can just check any pointer from each set
+ // for aliasing.
+ AliasAnalysis &AA = AST.getAliasAnalysis();
+ HashNodePair *L = getSomePointer();
+ HashNodePair *R = AS.getSomePointer();
+
+ // If the pointers are not a must-alias pair, this set becomes a may alias.
+ if (AA.alias(L->first, L->second.getSize(), R->first, R->second.getSize())
+ != AliasAnalysis::MustAlias)
+ AliasTy = MayAlias;
+ }
+
if (CallSites.empty()) { // Merge call sites...
if (!AS.CallSites.empty())
std::swap(CallSites, AS.CallSites);
CallSites.insert(CallSites.end(), AS.CallSites.begin(), AS.CallSites.end());
AS.CallSites.clear();
}
-
+
AS.Forward = this; // Forward across AS now...
addRef(); // AS is now pointing to us...
void AliasSet::addCallSite(CallSite CS, AliasAnalysis &AA) {
CallSites.push_back(CS);
- if (Function *F = CS.getCalledFunction()) {
- if (AA.doesNotAccessMemory(F))
- return;
- else if (AA.onlyReadsMemory(F)) {
- AliasTy = MayAlias;
- AccessTy |= Refs;
- return;
- }
+ AliasAnalysis::ModRefBehavior Behavior = AA.getModRefBehavior(CS);
+ if (Behavior == AliasAnalysis::DoesNotAccessMemory)
+ return;
+ else if (Behavior == AliasAnalysis::OnlyReadsMemory) {
+ AliasTy = MayAlias;
+ AccessTy |= Refs;
+ return;
}
// FIXME: This should use mod/ref information to make this not suck so bad
}
bool AliasSet::aliasesCallSite(CallSite CS, AliasAnalysis &AA) const {
- if (Function *F = CS.getCalledFunction())
- if (AA.doesNotAccessMemory(F))
- return false;
+ if (AA.doesNotAccessMemory(CS))
+ return false;
if (AA.hasNoModRefInfoForCalls())
return true;
AliasSet *FoundSet = 0;
for (iterator I = begin(), E = end(); I != E; ++I)
if (!I->Forward && I->aliasesPointer(Ptr, Size, AA)) {
- if (FoundSet == 0) { // If this is the first alias set ptr can go into...
+ if (FoundSet == 0) { // If this is the first alias set ptr can go into.
FoundSet = I; // Remember it.
- } else { // Otherwise, we must merge the sets...
- FoundSet->mergeSetIn(*I); // Merge in contents...
+ } else { // Otherwise, we must merge the sets.
+ FoundSet->mergeSetIn(*I, *this); // Merge in contents.
}
}
AliasSet *FoundSet = 0;
for (iterator I = begin(), E = end(); I != E; ++I)
if (!I->Forward && I->aliasesCallSite(CS, AA)) {
- if (FoundSet == 0) { // If this is the first alias set ptr can go into...
+ if (FoundSet == 0) { // If this is the first alias set ptr can go into.
FoundSet = I; // Remember it.
- } else if (!I->Forward) { // Otherwise, we must merge the sets...
- FoundSet->mergeSetIn(*I); // Merge in contents...
+ } else if (!I->Forward) { // Otherwise, we must merge the sets.
+ FoundSet->mergeSetIn(*I, *this); // Merge in contents.
}
}
bool AliasSetTracker::add(LoadInst *LI) {
bool NewPtr;
AliasSet &AS = addPointer(LI->getOperand(0),
- AA.getTargetData().getTypeSize(LI->getType()),
+ AA.getTargetData().getTypeStoreSize(LI->getType()),
AliasSet::Refs, NewPtr);
if (LI->isVolatile()) AS.setVolatile();
return NewPtr;
bool NewPtr;
Value *Val = SI->getOperand(0);
AliasSet &AS = addPointer(SI->getOperand(1),
- AA.getTargetData().getTypeSize(Val->getType()),
+ AA.getTargetData().getTypeStoreSize(Val->getType()),
AliasSet::Mods, NewPtr);
if (SI->isVolatile()) AS.setVolatile();
return NewPtr;
bool AliasSetTracker::add(FreeInst *FI) {
bool NewPtr;
- AliasSet &AS = addPointer(FI->getOperand(0), ~0,
- AliasSet::Mods, NewPtr);
+ addPointer(FI->getOperand(0), ~0, AliasSet::Mods, NewPtr);
+ return NewPtr;
+}
+
+bool AliasSetTracker::add(VAArgInst *VAAI) {
+ bool NewPtr;
+ addPointer(VAAI->getOperand(0), ~0, AliasSet::ModRef, NewPtr);
return NewPtr;
}
bool AliasSetTracker::add(CallSite CS) {
- if (Function *F = CS.getCalledFunction())
- if (AA.doesNotAccessMemory(F))
- return true; // doesn't alias anything
+ if (AA.doesNotAccessMemory(CS))
+ return true; // doesn't alias anything
AliasSet *AS = findAliasSetForCallSite(CS);
if (!AS) {
return add(II);
else if (FreeInst *FI = dyn_cast<FreeInst>(I))
return add(FI);
+ else if (VAArgInst *VAAI = dyn_cast<VAArgInst>(I))
+ return add(VAAI);
return true;
}
// Loop over all of the pointers in this alias set...
AliasSet::iterator I = AS.begin(), E = AS.end();
bool X;
- for (; I != E; ++I)
- addPointer(I.getPointer(), I.getSize(),
- (AliasSet::AccessType)AS.AccessTy, X);
+ for (; I != E; ++I) {
+ AliasSet &NewAS = addPointer(I.getPointer(), I.getSize(),
+ (AliasSet::AccessType)AS.AccessTy, X);
+ if (AS.isVolatile()) NewAS.setVolatile();
+ }
}
}
/// 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);
+ // Drop all call sites.
+ AS.CallSites.clear();
+
+ // Clear the alias set.
+ unsigned NumRefs = 0;
+ while (!AS.empty()) {
+ AliasSet::HashNodePair *P = AS.PtrList;
+
+ // Unlink from the list of values.
+ P->second.removeFromList();
+
+ // Remember how many references need to be dropped.
+ ++NumRefs;
+
+ // Finally, remove the entry.
+ Value *Remove = P->first; // Take a copy because it is invalid to pass
+ PointerMap.erase(Remove); // a reference to the data being erased.
+ }
+
+ // Stop using the alias set, removing it.
+ AS.RefCount -= NumRefs;
+ if (AS.RefCount == 0)
+ AS.removeFromTracker(*this);
}
bool AliasSetTracker::remove(Value *Ptr, unsigned Size) {
}
bool AliasSetTracker::remove(LoadInst *LI) {
- unsigned Size = AA.getTargetData().getTypeSize(LI->getType());
+ unsigned Size = AA.getTargetData().getTypeStoreSize(LI->getType());
AliasSet *AS = findAliasSetForPointer(LI->getOperand(0), Size);
if (!AS) return false;
remove(*AS);
}
bool AliasSetTracker::remove(StoreInst *SI) {
- unsigned Size = AA.getTargetData().getTypeSize(SI->getOperand(0)->getType());
+ unsigned Size =
+ AA.getTargetData().getTypeStoreSize(SI->getOperand(0)->getType());
AliasSet *AS = findAliasSetForPointer(SI->getOperand(1), Size);
if (!AS) return false;
remove(*AS);
return true;
}
+bool AliasSetTracker::remove(VAArgInst *VAAI) {
+ AliasSet *AS = findAliasSetForPointer(VAAI->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
+ if (AA.doesNotAccessMemory(CS))
+ return false; // doesn't alias anything
AliasSet *AS = findAliasSetForCallSite(CS);
if (!AS) return false;
return remove(CI);
else if (FreeInst *FI = dyn_cast<FreeInst>(I))
return remove(FI);
+ else if (VAArgInst *VAAI = dyn_cast<VAArgInst>(I))
+ return remove(VAAI);
return true;
}
// Notify the alias analysis implementation that this value is gone.
AA.deleteValue(PtrVal);
+ // If this is a call instruction, remove the callsite from the appropriate
+ // AliasSet.
+ CallSite CS = CallSite::get(PtrVal);
+ if (CS.getInstruction())
+ if (!AA.doesNotAccessMemory(CS))
+ if (AliasSet *AS = findAliasSetForCallSite(CS))
+ AS->removeCallSite(CS);
+
// First, look up the PointerRec for this pointer.
hash_map<Value*, AliasSet::PointerRec>::iterator I = PointerMap.find(PtrVal);
if (I == PointerMap.end()) return; // Noop
void AliasSet::print(std::ostream &OS) const {
OS << " AliasSet[" << (void*)this << "," << RefCount << "] ";
- OS << (AliasTy == MustAlias ? "must" : "may ") << " alias, ";
+ OS << (AliasTy == MustAlias ? "must" : "may") << " alias, ";
switch (AccessTy) {
case NoModRef: OS << "No access "; break;
case Refs : OS << "Ref "; break;
OS << " forwarding to " << (void*)Forward;
- if (begin() != end()) {
+ if (!empty()) {
OS << "Pointers: ";
for (iterator I = begin(), E = end(); I != E; ++I) {
if (I != begin()) OS << ", ";
for (unsigned i = 0, e = CallSites.size(); i != e; ++i) {
if (i) OS << ", ";
WriteAsOperand(OS, CallSites[i].getCalledValue());
- }
+ }
}
OS << "\n";
}
OS << "\n";
}
-void AliasSet::dump() const { print (std::cerr); }
-void AliasSetTracker::dump() const { print(std::cerr); }
+void AliasSet::dump() const { print (cerr); }
+void AliasSetTracker::dump() const { print(cerr); }
//===----------------------------------------------------------------------===//
// AliasSetPrinter Pass
//===----------------------------------------------------------------------===//
namespace {
- class AliasSetPrinter : public FunctionPass {
+ class VISIBILITY_HIDDEN AliasSetPrinter : public FunctionPass {
AliasSetTracker *Tracker;
public:
+ static char ID; // Pass identification, replacement for typeid
+ AliasSetPrinter() : FunctionPass(&ID) {}
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<AliasAnalysis>();
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I)
Tracker->add(&*I);
- return false;
- }
-
- /// print - Convert to human readable form
- virtual void print(std::ostream &OS) const {
- Tracker->print(OS);
- }
-
- virtual void releaseMemory() {
+ Tracker->print(cerr);
delete Tracker;
+ return false;
}
};
- RegisterPass<AliasSetPrinter> X("print-alias-sets", "Alias Set Printer",
- PassInfo::Analysis | PassInfo::Optimization);
}
+
+char AliasSetPrinter::ID = 0;
+static RegisterPass<AliasSetPrinter>
+X("print-alias-sets", "Alias Set Printer", false, true);