llvm-6502/lib/Analysis/NoAliasAnalysis.cpp
Chandler Carruth 4d7ed3960c [PM/AA] Remove the Location typedef from the AliasAnalysis class now
that it is its own entity in the form of MemoryLocation, and update all
the callers.

This is an entirely mechanical change. References to "Location" within
AA subclases become "MemoryLocation", and elsewhere
"AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps
out-of-tree folks update.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239885 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 07:18:54 +00:00

97 lines
3.4 KiB
C++

//===- NoAliasAnalysis.cpp - Minimal Alias Analysis Impl ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the default implementation of the Alias Analysis interface
// that simply returns "I don't know" for all queries.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
using namespace llvm;
namespace {
/// 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 {
static char ID; // Class identification, replacement for typeinfo
NoAA() : ImmutablePass(ID) {
initializeNoAAPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {}
bool doInitialization(Module &M) override {
// Note: NoAA does not call InitializeAliasAnalysis because it's
// special and does not support chaining.
DL = &M.getDataLayout();
return true;
}
AliasResult alias(const MemoryLocation &LocA,
const MemoryLocation &LocB) override {
return MayAlias;
}
ModRefBehavior getModRefBehavior(ImmutableCallSite CS) override {
return UnknownModRefBehavior;
}
ModRefBehavior getModRefBehavior(const Function *F) override {
return UnknownModRefBehavior;
}
bool pointsToConstantMemory(const MemoryLocation &Loc,
bool OrLocal) override {
return false;
}
ModRefResult getArgModRefInfo(ImmutableCallSite CS,
unsigned ArgIdx) override {
return ModRef;
}
ModRefResult getModRefInfo(ImmutableCallSite CS,
const MemoryLocation &Loc) override {
return ModRef;
}
ModRefResult getModRefInfo(ImmutableCallSite CS1,
ImmutableCallSite CS2) override {
return ModRef;
}
void deleteValue(Value *V) override {}
void copyValue(Value *From, Value *To) override {}
void addEscapingUse(Use &U) override {}
/// getAdjustedAnalysisPointer - This method is used when a pass implements
/// an analysis interface through multiple inheritance. If needed, it
/// should override this to adjust the this pointer as needed for the
/// specified pass info.
void *getAdjustedAnalysisPointer(const void *ID) override {
if (ID == &AliasAnalysis::ID)
return (AliasAnalysis*)this;
return this;
}
};
} // End of anonymous namespace
// Register this pass...
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(); }