1263508Sdim//===- ProvenanceAnalysis.h - ObjC ARC Optimization ---*- C++ -*-----------===// 2249259Sdim// 3249259Sdim// The LLVM Compiler Infrastructure 4249259Sdim// 5249259Sdim// This file is distributed under the University of Illinois Open Source 6249259Sdim// License. See LICENSE.TXT for details. 7249259Sdim// 8249259Sdim//===----------------------------------------------------------------------===// 9249259Sdim/// \file 10249259Sdim/// 11249259Sdim/// This file declares a special form of Alias Analysis called ``Provenance 12249259Sdim/// Analysis''. The word ``provenance'' refers to the history of the ownership 13249259Sdim/// of an object. Thus ``Provenance Analysis'' is an analysis which attempts to 14249259Sdim/// use various techniques to determine if locally 15249259Sdim/// 16249259Sdim/// WARNING: This file knows about certain library functions. It recognizes them 17249259Sdim/// by name, and hardwires knowledge of their semantics. 18249259Sdim/// 19249259Sdim/// WARNING: This file knows about how certain Objective-C library functions are 20249259Sdim/// used. Naive LLVM IR transformations which would otherwise be 21249259Sdim/// behavior-preserving may break these assumptions. 22249259Sdim/// 23249259Sdim//===----------------------------------------------------------------------===// 24249259Sdim 25249259Sdim#ifndef LLVM_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H 26249259Sdim#define LLVM_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H 27249259Sdim 28249259Sdim#include "llvm/ADT/DenseMap.h" 29249259Sdim 30249259Sdimnamespace llvm { 31249259Sdim class Value; 32249259Sdim class AliasAnalysis; 33249259Sdim class PHINode; 34249259Sdim class SelectInst; 35249259Sdim} 36249259Sdim 37249259Sdimnamespace llvm { 38249259Sdimnamespace objcarc { 39249259Sdim 40249259Sdim/// \brief This is similar to BasicAliasAnalysis, and it uses many of the same 41249259Sdim/// techniques, except it uses special ObjC-specific reasoning about pointer 42249259Sdim/// relationships. 43249259Sdim/// 44249259Sdim/// In this context ``Provenance'' is defined as the history of an object's 45249259Sdim/// ownership. Thus ``Provenance Analysis'' is defined by using the notion of 46249259Sdim/// an ``independent provenance source'' of a pointer to determine whether or 47249259Sdim/// not two pointers have the same provenance source and thus could 48249259Sdim/// potentially be related. 49249259Sdimclass ProvenanceAnalysis { 50249259Sdim AliasAnalysis *AA; 51249259Sdim 52249259Sdim typedef std::pair<const Value *, const Value *> ValuePairTy; 53249259Sdim typedef DenseMap<ValuePairTy, bool> CachedResultsTy; 54249259Sdim CachedResultsTy CachedResults; 55249259Sdim 56249259Sdim bool relatedCheck(const Value *A, const Value *B); 57249259Sdim bool relatedSelect(const SelectInst *A, const Value *B); 58249259Sdim bool relatedPHI(const PHINode *A, const Value *B); 59249259Sdim 60249259Sdim void operator=(const ProvenanceAnalysis &) LLVM_DELETED_FUNCTION; 61249259Sdim ProvenanceAnalysis(const ProvenanceAnalysis &) LLVM_DELETED_FUNCTION; 62249259Sdim 63249259Sdimpublic: 64249259Sdim ProvenanceAnalysis() {} 65249259Sdim 66249259Sdim void setAA(AliasAnalysis *aa) { AA = aa; } 67249259Sdim 68249259Sdim AliasAnalysis *getAA() const { return AA; } 69249259Sdim 70249259Sdim bool related(const Value *A, const Value *B); 71249259Sdim 72249259Sdim void clear() { 73249259Sdim CachedResults.clear(); 74249259Sdim } 75249259Sdim}; 76249259Sdim 77249259Sdim} // end namespace objcarc 78249259Sdim} // end namespace llvm 79249259Sdim 80249259Sdim#endif // LLVM_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H 81