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

llvm-svn: 13683
This commit is contained in:
Chris Lattner 2004-05-23 21:15:12 +00:00
parent 1336a3f17a
commit 7ccc4c2ed9

View File

@ -36,13 +36,55 @@ using namespace llvm;
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 @@ namespace {
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) {