+ // If the pointer is a pointer to constant memory, then it could not have been
+ // modified by this store.
+ if (pointsToConstantMemory(Loc))
+ return NoModRef;
+
+ // Otherwise, a store just writes.
+ return Mod;
+}
+
+AliasAnalysis::ModRefResult
+AliasAnalysis::getModRefInfo(const VAArgInst *V, const Location &Loc) {
+ // If the va_arg address cannot alias the pointer in question, then the
+ // specified memory cannot be accessed by the va_arg.
+ if (!alias(getLocation(V), Loc))
+ return NoModRef;
+
+ // If the pointer is a pointer to constant memory, then it could not have been
+ // modified by this va_arg.
+ if (pointsToConstantMemory(Loc))
+ return NoModRef;
+
+ // Otherwise, a va_arg reads and writes.
+ return ModRef;
+}
+
+// AliasAnalysis destructor: DO NOT move this to the header file for
+// AliasAnalysis or else clients of the AliasAnalysis class may not depend on
+// the AliasAnalysis.o file in the current .a file, causing alias analysis
+// support to not be included in the tool correctly!
+//
+AliasAnalysis::~AliasAnalysis() {}
+
+/// InitializeAliasAnalysis - Subclasses must call this method to initialize the
+/// AliasAnalysis interface before any other methods are called.
+///
+void AliasAnalysis::InitializeAliasAnalysis(Pass *P) {
+ TD = P->getAnalysisIfAvailable<TargetData>();
+ AA = &P->getAnalysis<AliasAnalysis>();
+}
+
+// getAnalysisUsage - All alias analysis implementations should invoke this
+// directly (using AliasAnalysis::getAnalysisUsage(AU)).
+void AliasAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<AliasAnalysis>(); // All AA's chain
+}
+
+/// getTypeStoreSize - Return the TargetData store size for the given type,
+/// if known, or a conservative value otherwise.
+///
+uint64_t AliasAnalysis::getTypeStoreSize(const Type *Ty) {
+ return TD ? TD->getTypeStoreSize(Ty) : UnknownSize;
+}
+
+/// canBasicBlockModify - Return true if it is possible for execution of the
+/// specified basic block to modify the value pointed to by Ptr.
+///
+bool AliasAnalysis::canBasicBlockModify(const BasicBlock &BB,
+ const Location &Loc) {
+ return canInstructionRangeModify(BB.front(), BB.back(), Loc);
+}
+
+/// canInstructionRangeModify - Return true if it is possible for the execution
+/// of the specified instructions to modify the value pointed to by Ptr. The
+/// instructions to consider are all of the instructions in the range of [I1,I2]
+/// INCLUSIVE. I1 and I2 must be in the same basic block.
+///
+bool AliasAnalysis::canInstructionRangeModify(const Instruction &I1,
+ const Instruction &I2,
+ const Location &Loc) {
+ assert(I1.getParent() == I2.getParent() &&
+ "Instructions not in same basic block!");
+ BasicBlock::const_iterator I = &I1;
+ BasicBlock::const_iterator E = &I2;
+ ++E; // Convert from inclusive to exclusive range.
+
+ for (; I != E; ++I) // Check every instruction in range
+ if (getModRefInfo(I, Loc) & Mod)
+ return true;
+ return false;
+}
+
+/// isNoAliasCall - Return true if this pointer is returned by a noalias
+/// function.
+bool llvm::isNoAliasCall(const Value *V) {
+ if (isa<CallInst>(V) || isa<InvokeInst>(V))
+ return ImmutableCallSite(cast<Instruction>(V))
+ .paramHasAttr(0, Attribute::NoAlias);
+ return false;
+}
+
+/// isIdentifiedObject - Return true if this pointer refers to a distinct and
+/// identifiable object. This returns true for:
+/// Global Variables and Functions (but not Global Aliases)
+/// Allocas and Mallocs
+/// ByVal and NoAlias Arguments
+/// NoAlias returns
+///
+bool llvm::isIdentifiedObject(const Value *V) {
+ if (isa<AllocaInst>(V))
+ return true;
+ if (isa<GlobalValue>(V) && !isa<GlobalAlias>(V))
+ return true;
+ if (isNoAliasCall(V))
+ return true;
+ if (const Argument *A = dyn_cast<Argument>(V))
+ return A->hasNoAliasAttr() || A->hasByValAttr();
+ return false;