llvm/lib/Analysis/NoAliasAnalysis.cpp
Chandler Carruth 0b8c9a80f2 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-02 11:36:10 +00:00

89 lines
3.1 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/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());
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
}
virtual void initializePass() {
// Note: NoAA does not call InitializeAliasAnalysis because it's
// special and does not support chaining.
TD = getAnalysisIfAvailable<DataLayout>();
}
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) {}
/// 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.
virtual void *getAdjustedAnalysisPointer(const void *ID) {
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(); }