mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-23 19:23:23 +01:00
ae65e281f3
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
87 lines
2.9 KiB
C++
87 lines
2.9 KiB
C++
//===- ProvenanceAnalysis.h - ObjC ARC Optimization -------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
/// \file
|
|
///
|
|
/// This file declares a special form of Alias Analysis called ``Provenance
|
|
/// Analysis''. The word ``provenance'' refers to the history of the ownership
|
|
/// of an object. Thus ``Provenance Analysis'' is an analysis which attempts to
|
|
/// use various techniques to determine if locally
|
|
///
|
|
/// WARNING: This file knows about certain library functions. It recognizes them
|
|
/// by name, and hardwires knowledge of their semantics.
|
|
///
|
|
/// WARNING: This file knows about how certain Objective-C library functions are
|
|
/// used. Naive LLVM IR transformations which would otherwise be
|
|
/// behavior-preserving may break these assumptions.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_LIB_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H
|
|
#define LLVM_LIB_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H
|
|
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/Analysis/AliasAnalysis.h"
|
|
#include "llvm/IR/ValueHandle.h"
|
|
#include <utility>
|
|
|
|
namespace llvm {
|
|
|
|
class DataLayout;
|
|
class PHINode;
|
|
class SelectInst;
|
|
class Value;
|
|
|
|
namespace objcarc {
|
|
|
|
/// This is similar to BasicAliasAnalysis, and it uses many of the same
|
|
/// techniques, except it uses special ObjC-specific reasoning about pointer
|
|
/// relationships.
|
|
///
|
|
/// In this context ``Provenance'' is defined as the history of an object's
|
|
/// ownership. Thus ``Provenance Analysis'' is defined by using the notion of
|
|
/// an ``independent provenance source'' of a pointer to determine whether or
|
|
/// not two pointers have the same provenance source and thus could
|
|
/// potentially be related.
|
|
class ProvenanceAnalysis {
|
|
AliasAnalysis *AA;
|
|
|
|
using ValuePairTy = std::pair<const Value *, const Value *>;
|
|
using CachedResultsTy = DenseMap<ValuePairTy, bool>;
|
|
|
|
CachedResultsTy CachedResults;
|
|
|
|
DenseMap<const Value *, WeakTrackingVH> UnderlyingObjCPtrCache;
|
|
|
|
bool relatedCheck(const Value *A, const Value *B, const DataLayout &DL);
|
|
bool relatedSelect(const SelectInst *A, const Value *B);
|
|
bool relatedPHI(const PHINode *A, const Value *B);
|
|
|
|
public:
|
|
ProvenanceAnalysis() = default;
|
|
ProvenanceAnalysis(const ProvenanceAnalysis &) = delete;
|
|
ProvenanceAnalysis &operator=(const ProvenanceAnalysis &) = delete;
|
|
|
|
void setAA(AliasAnalysis *aa) { AA = aa; }
|
|
|
|
AliasAnalysis *getAA() const { return AA; }
|
|
|
|
bool related(const Value *A, const Value *B, const DataLayout &DL);
|
|
|
|
void clear() {
|
|
CachedResults.clear();
|
|
UnderlyingObjCPtrCache.clear();
|
|
}
|
|
};
|
|
|
|
} // end namespace objcarc
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_LIB_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H
|