NoAliasAnalysis.cpp [plain text]
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetData.h"
using namespace llvm;
namespace {
struct NoAA : public ImmutablePass, public AliasAnalysis {
static char ID; NoAA() : ImmutablePass(ID) {
initializeNoAAPass(*PassRegistry::getPassRegistry());
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
}
virtual void initializePass() {
TD = getAnalysisIfAvailable<TargetData>();
}
virtual AliasResult alias(const Location &LocA, const Location &LocB) {
return MayAlias;
}
virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS) {
return UnknownModRefBehavior;
}
virtual ModRefBehavior getModRefBehavior(const Function *F) {
return UnknownModRefBehavior;
}
virtual bool pointsToConstantMemory(const Location &Loc,
bool OrLocal) {
return false;
}
virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
const Location &Loc) {
return ModRef;
}
virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
ImmutableCallSite CS2) {
return ModRef;
}
virtual void deleteValue(Value *V) {}
virtual void copyValue(Value *From, Value *To) {}
virtual void addEscapingUse(Use &U) {}
virtual void *getAdjustedAnalysisPointer(const void *ID) {
if (ID == &AliasAnalysis::ID)
return (AliasAnalysis*)this;
return this;
}
};
}
char NoAA::ID = 0;
INITIALIZE_AG_PASS(NoAA, AliasAnalysis, "no-aa",
"No Alias Analysis (always returns 'may' alias)",
true, true, true)
ImmutablePass *llvm::createNoAAPass() { return new NoAA(); }