Move the -no-aa AA implementation into this file since both of these
alias analysis implementations are special: they do not autoforward to a
chained implementation of alias analysis
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13683 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 8fc561e..5ccaa5c 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -36,13 +36,55 @@
void llvm::BasicAAStub() {}
namespace {
- struct BasicAliasAnalysis : public ImmutablePass, public AliasAnalysis {
-
+ /// NoAA - This class implements the -no-aa pass, which always returns "I
+ /// don't know" for alias queries. NoAA is unlike other alias analysis
+ /// implementations, in that it does not chain to a previous analysis. As
+ /// such it doesn't follow many of the rules that other alias analyses must.
+ ///
+ struct NoAA : public ImmutablePass, public AliasAnalysis {
+ virtual AliasResult alias(const Value *V1, unsigned V1Size,
+ const Value *V2, unsigned V2Size) {
+ return MayAlias;
+ }
+
+ virtual void getMustAliases(Value *P, std::vector<Value*> &RetVals) { }
+ virtual bool pointsToConstantMemory(const Value *P) { return false; }
+ virtual bool doesNotAccessMemory(Function *F) { return false; }
+ virtual bool onlyReadsMemory(Function *F) { return false; }
+ virtual ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size) {
+ return ModRef;
+ }
+ virtual ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
+ return ModRef;
+ }
+ virtual bool hasNoModRefInfoForCalls() const { return true; }
+
+ virtual void deleteValue(Value *V) {}
+ virtual void copyValue(Value *From, Value *To) {}
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {}
+ };
+
+ // Register this pass...
+ RegisterOpt<NoAA>
+ U("no-aa", "No Alias Analysis (always returns 'may' alias)");
+
+ // Declare that we implement the AliasAnalysis interface
+ RegisterAnalysisGroup<AliasAnalysis, NoAA> V;
+} // End of anonymous namespace
+
+
+namespace {
+ /// BasicAliasAnalysis - This is the default alias analysis implementation.
+ /// Because it doesn't chain to a previous alias analysis (like -no-aa), it
+ /// derives from the NoAA class.
+ struct BasicAliasAnalysis : public NoAA {
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AliasAnalysis::getAnalysisUsage(AU);
+ AU.addRequired<TargetData>();
}
- virtual void initializePass();
+ virtual void initializePass() {
+ TD = &getAnalysis<TargetData>();
+ }
AliasResult alias(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size);
@@ -79,10 +121,6 @@
RegisterAnalysisGroup<AliasAnalysis, BasicAliasAnalysis, true> Y;
} // End of anonymous namespace
-void BasicAliasAnalysis::initializePass() {
- InitializeAliasAnalysis(this);
-}
-
// hasUniqueAddress - Return true if the specified value points to something
// with a unique, discernable, address.
static inline bool hasUniqueAddress(const Value *V) {