119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===- ObjCARC.cpp - ObjC ARC Optimization --------------------------------===// 219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// The LLVM Compiler Infrastructure 419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// This file is distributed under the University of Illinois Open Source 619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// License. See LICENSE.TXT for details. 719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 1019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// This file defines ObjC ARC optimizations. ARC stands for 1119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// Automatic Reference Counting and is a system for managing reference counts 1219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// for objects in Objective C. 1319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 1419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// The optimizations performed include elimination of redundant, partially 1519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// redundant, and inconsequential reference count operations, elimination of 1619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// redundant weak pointer operations, pattern-matching and replacement of 1719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// low-level operations into higher-level operations, and numerous minor 1819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// simplifications. 1919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 2019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// This file also defines a simple ARC-aware AliasAnalysis. 2119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 2219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// WARNING: This file knows about certain library functions. It recognizes them 2319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// by name, and hardwires knowedge of their semantics. 2419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 2519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// WARNING: This file knows about how certain Objective-C library functions are 2619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// used. Naive LLVM IR transformations which would otherwise be 2719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// behavior-preserving may break these assumptions. 2819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 2919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 3019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 3119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#define DEBUG_TYPE "objc-arc" 3219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Function.h" 3319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Intrinsics.h" 3419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/GlobalVariable.h" 3519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/DerivedTypes.h" 3619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Module.h" 3719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Analysis/ValueTracking.h" 3819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Transforms/Utils/Local.h" 3919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Support/CallSite.h" 4019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Support/CommandLine.h" 4119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/ADT/StringSwitch.h" 4219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/ADT/DenseMap.h" 4319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/ADT/STLExtras.h" 4419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanusing namespace llvm; 4519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 4619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// A handy option to enable/disable all optimizations in this file. 4719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic cl::opt<bool> EnableARCOpts("enable-objc-arc-opts", cl::init(true)); 4819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 4919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 5019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// Misc. Utilities 5119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 5219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 5319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 5419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// MapVector - An associative container with fast insertion-order 5519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// (deterministic) iteration over its elements. Plus the special 5619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// blot operation. 5719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman template<class KeyT, class ValueT> 5819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class MapVector { 5919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Map - Map keys to indices in Vector. 6019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef DenseMap<KeyT, size_t> MapTy; 6119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapTy Map; 6219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 6319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Vector - Keys and values. 6419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef std::vector<std::pair<KeyT, ValueT> > VectorTy; 6519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman VectorTy Vector; 6619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 6719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 6819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef typename VectorTy::iterator iterator; 6919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef typename VectorTy::const_iterator const_iterator; 7019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman iterator begin() { return Vector.begin(); } 7119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman iterator end() { return Vector.end(); } 7219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const_iterator begin() const { return Vector.begin(); } 7319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const_iterator end() const { return Vector.end(); } 7419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 7519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#ifdef XDEBUG 7619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ~MapVector() { 7719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(Vector.size() >= Map.size()); // May differ due to blotting. 7819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (typename MapTy::const_iterator I = Map.begin(), E = Map.end(); 7919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman I != E; ++I) { 8019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(I->second < Vector.size()); 8119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(Vector[I->second].first == I->first); 8219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 8319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (typename VectorTy::const_iterator I = Vector.begin(), 8419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman E = Vector.end(); I != E; ++I) 8519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(!I->first || 8619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (Map.count(I->first) && 8719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Map[I->first] == size_t(I - Vector.begin()))); 8819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 8919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#endif 9019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 9119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ValueT &operator[](KeyT Arg) { 9219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<typename MapTy::iterator, bool> Pair = 9319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Map.insert(std::make_pair(Arg, size_t(0))); 9419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pair.second) { 9519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Pair.first->second = Vector.size(); 9619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Vector.push_back(std::make_pair(Arg, ValueT())); 9719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Vector.back().second; 9819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 9919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Vector[Pair.first->second].second; 10019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 10119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 10219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<iterator, bool> 10319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman insert(const std::pair<KeyT, ValueT> &InsertPair) { 10419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<typename MapTy::iterator, bool> Pair = 10519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Map.insert(std::make_pair(InsertPair.first, size_t(0))); 10619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pair.second) { 10719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Pair.first->second = Vector.size(); 10819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Vector.push_back(InsertPair); 10919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return std::make_pair(llvm::prior(Vector.end()), true); 11019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 11119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return std::make_pair(Vector.begin() + Pair.first->second, false); 11219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 11319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 11419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const_iterator find(KeyT Key) const { 11519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typename MapTy::const_iterator It = Map.find(Key); 11619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (It == Map.end()) return Vector.end(); 11719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Vector.begin() + It->second; 11819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 11919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 12019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// blot - This is similar to erase, but instead of removing the element 12119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// from the vector, it just zeros out the key in the vector. This leaves 12219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// iterators intact, but clients must be prepared for zeroed-out keys when 12319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// iterating. 12419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void blot(KeyT Key) { 12519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typename MapTy::iterator It = Map.find(Key); 12619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (It == Map.end()) return; 12719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Vector[It->second].first = KeyT(); 12819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Map.erase(It); 12919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 13019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 13119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void clear() { 13219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Map.clear(); 13319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Vector.clear(); 13419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 13519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 13619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 13719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 13819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 13919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// ARC Utilities. 14019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 14119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 14219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 14319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// InstructionClass - A simple classification for instructions. 14419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman enum InstructionClass { 14519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_Retain, ///< objc_retain 14619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_RetainRV, ///< objc_retainAutoreleasedReturnValue 14719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_RetainBlock, ///< objc_retainBlock 14819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_Release, ///< objc_release 14919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_Autorelease, ///< objc_autorelease 15019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_AutoreleaseRV, ///< objc_autoreleaseReturnValue 15119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_AutoreleasepoolPush, ///< objc_autoreleasePoolPush 15219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_AutoreleasepoolPop, ///< objc_autoreleasePoolPop 15319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_NoopCast, ///< objc_retainedObject, etc. 15419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_FusedRetainAutorelease, ///< objc_retainAutorelease 15519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_FusedRetainAutoreleaseRV, ///< objc_retainAutoreleaseReturnValue 15619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_LoadWeakRetained, ///< objc_loadWeakRetained (primitive) 15719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_StoreWeak, ///< objc_storeWeak (primitive) 15819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_InitWeak, ///< objc_initWeak (derived) 15919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_LoadWeak, ///< objc_loadWeak (derived) 16019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_MoveWeak, ///< objc_moveWeak (derived) 16119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_CopyWeak, ///< objc_copyWeak (derived) 16219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_DestroyWeak, ///< objc_destroyWeak (derived) 16319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_CallOrUser, ///< could call objc_release and/or "use" pointers 16419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_Call, ///< could call objc_release 16519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_User, ///< could "use" a pointer 16619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IC_None ///< anything else 16719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 16819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 16919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 17019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsPotentialUse - Test whether the given value is possible a 17119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// reference-counted pointer. 17219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsPotentialUse(const Value *Op) { 17319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Pointers to static or stack storage are not reference-counted pointers. 17419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<Constant>(Op) || isa<AllocaInst>(Op)) 17519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 17619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Special arguments are not reference-counted. 17719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const Argument *Arg = dyn_cast<Argument>(Op)) 17819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Arg->hasByValAttr() || 17919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg->hasNestAttr() || 18019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg->hasStructRetAttr()) 18119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 18219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Only consider values with pointer types, and not function pointers. 18319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PointerType *Ty = dyn_cast<PointerType>(Op->getType()); 18419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Ty || isa<FunctionType>(Ty->getElementType())) 18519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 18619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Conservatively assume anything else is a potential use. 18719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 18819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 18919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 19019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// GetCallSiteClass - Helper for GetInstructionClass. Determines what kind 19119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// of construct CS is. 19219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic InstructionClass GetCallSiteClass(ImmutableCallSite CS) { 19319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ImmutableCallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 19419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman I != E; ++I) 19519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(*I)) 19619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return CS.onlyReadsMemory() ? IC_User : IC_CallOrUser; 19719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 19819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return CS.onlyReadsMemory() ? IC_None : IC_Call; 19919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 20019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 20119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// GetFunctionClass - Determine if F is one of the special known Functions. 20219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// If it isn't, return IC_CallOrUser. 20319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic InstructionClass GetFunctionClass(const Function *F) { 20419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); 20519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 20619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // No arguments. 20719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AI == AE) 20819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StringSwitch<InstructionClass>(F->getName()) 20919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_autoreleasePoolPush", IC_AutoreleasepoolPush) 21019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Default(IC_CallOrUser); 21119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 21219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // One argument. 21319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Argument *A0 = AI++; 21419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AI == AE) 21519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Argument is a pointer. 21619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PointerType *PTy = dyn_cast<PointerType>(A0->getType())) { 21719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *ETy = PTy->getElementType(); 21819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Argument is i8*. 21919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ETy->isIntegerTy(8)) 22019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StringSwitch<InstructionClass>(F->getName()) 22119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retain", IC_Retain) 22219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retainAutoreleasedReturnValue", IC_RetainRV) 22319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retainBlock", IC_RetainBlock) 22419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_release", IC_Release) 22519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_autorelease", IC_Autorelease) 22619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_autoreleaseReturnValue", IC_AutoreleaseRV) 22719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_autoreleasePoolPop", IC_AutoreleasepoolPop) 22819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retainedObject", IC_NoopCast) 22919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_unretainedObject", IC_NoopCast) 23019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_unretainedPointer", IC_NoopCast) 23119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retain_autorelease", IC_FusedRetainAutorelease) 23219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retainAutorelease", IC_FusedRetainAutorelease) 23319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_retainAutoreleaseReturnValue",IC_FusedRetainAutoreleaseRV) 23419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Default(IC_CallOrUser); 23519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 23619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Argument is i8** 23719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PointerType *Pte = dyn_cast<PointerType>(ETy)) 23819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pte->getElementType()->isIntegerTy(8)) 23919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StringSwitch<InstructionClass>(F->getName()) 24019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_loadWeakRetained", IC_LoadWeakRetained) 24119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_loadWeak", IC_LoadWeak) 24219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_destroyWeak", IC_DestroyWeak) 24319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Default(IC_CallOrUser); 24419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 24519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 24619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Two arguments, first is i8**. 24719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Argument *A1 = AI++; 24819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AI == AE) 24919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PointerType *PTy = dyn_cast<PointerType>(A0->getType())) 25019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PointerType *Pte = dyn_cast<PointerType>(PTy->getElementType())) 25119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pte->getElementType()->isIntegerTy(8)) 25219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PointerType *PTy1 = dyn_cast<PointerType>(A1->getType())) { 25319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *ETy1 = PTy1->getElementType(); 25419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Second argument is i8* 25519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ETy1->isIntegerTy(8)) 25619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StringSwitch<InstructionClass>(F->getName()) 25719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_storeWeak", IC_StoreWeak) 25819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_initWeak", IC_InitWeak) 25919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Default(IC_CallOrUser); 26019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Second argument is i8**. 26119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PointerType *Pte1 = dyn_cast<PointerType>(ETy1)) 26219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pte1->getElementType()->isIntegerTy(8)) 26319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StringSwitch<InstructionClass>(F->getName()) 26419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_moveWeak", IC_MoveWeak) 26519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Case("objc_copyWeak", IC_CopyWeak) 26619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .Default(IC_CallOrUser); 26719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 26819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 26919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Anything else. 27019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_CallOrUser; 27119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 27219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 27319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// GetInstructionClass - Determine what kind of construct V is. 27419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic InstructionClass GetInstructionClass(const Value *V) { 27519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const Instruction *I = dyn_cast<Instruction>(V)) { 27619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Any instruction other than bitcast and gep with a pointer operand have a 27719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // use of an objc pointer. Bitcasts, GEPs, Selects, PHIs transfer a pointer 27819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // to a subsequent use, rather than using it themselves, in this sense. 27919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // As a short cut, several other opcodes are known to have no pointer 28019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // operands of interest. And ret is never followed by a release, so it's 28119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // not interesting to examine. 28219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (I->getOpcode()) { 28319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Call: { 28419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const CallInst *CI = cast<CallInst>(I); 28519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for calls to special functions. 28619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const Function *F = CI->getCalledFunction()) { 28719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetFunctionClass(F); 28819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class != IC_CallOrUser) 28919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class; 29019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 29119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // None of the intrinsic functions do objc_release. For intrinsics, the 29219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // only question is whether or not they may be users. 29319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (F->getIntrinsicID()) { 29419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case 0: break; 29519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Intrinsic::bswap: case Intrinsic::ctpop: 29619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Intrinsic::ctlz: case Intrinsic::cttz: 29719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Intrinsic::returnaddress: case Intrinsic::frameaddress: 29819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Intrinsic::stacksave: case Intrinsic::stackrestore: 29919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Intrinsic::vastart: case Intrinsic::vacopy: case Intrinsic::vaend: 30019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Don't let dbg info affect our results. 30119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Intrinsic::dbg_declare: case Intrinsic::dbg_value: 30219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Short cut: Some intrinsics obviously don't use ObjC pointers. 30319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_None; 30419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 30519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Function::const_arg_iterator AI = F->arg_begin(), 30619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AE = F->arg_end(); AI != AE; ++AI) 30719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(AI)) 30819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_User; 30919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_None; 31019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 31119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 31219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return GetCallSiteClass(CI); 31319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 31419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Invoke: 31519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return GetCallSiteClass(cast<InvokeInst>(I)); 31619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::BitCast: 31719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::GetElementPtr: 31819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Select: case Instruction::PHI: 31919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Ret: case Instruction::Br: 32019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Switch: case Instruction::IndirectBr: 32119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Alloca: case Instruction::VAArg: 32219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Add: case Instruction::FAdd: 32319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Sub: case Instruction::FSub: 32419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Mul: case Instruction::FMul: 32519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::SDiv: case Instruction::UDiv: case Instruction::FDiv: 32619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::SRem: case Instruction::URem: case Instruction::FRem: 32719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::Shl: case Instruction::LShr: case Instruction::AShr: 32819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::And: case Instruction::Or: case Instruction::Xor: 32919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::SExt: case Instruction::ZExt: case Instruction::Trunc: 33019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::IntToPtr: case Instruction::FCmp: 33119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::FPTrunc: case Instruction::FPExt: 33219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::FPToUI: case Instruction::FPToSI: 33319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::UIToFP: case Instruction::SIToFP: 33419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::InsertElement: case Instruction::ExtractElement: 33519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::ShuffleVector: 33619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::ExtractValue: 33719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 33819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case Instruction::ICmp: 33919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Comparing a pointer with null, or any other constant, isn't an 34019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // interesting use, because we don't care what the pointer points to, or 34119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // about the values of any other dynamic reference-counted pointers. 34219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(I->getOperand(1))) 34319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_User; 34419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 34519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 34619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For anything else, check all the operands. 34719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Note that this includes both operands of a Store: while the first 34819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // operand isn't actually being dereferenced, it is being stored to 34919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // memory where we can no longer track who might read it and dereference 35019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // it, so we have to consider it potentially used. 35119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (User::const_op_iterator OI = I->op_begin(), OE = I->op_end(); 35219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OI != OE; ++OI) 35319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(*OI)) 35419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_User; 35519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 35619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 35719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 35819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Otherwise, it's totally inert for ARC purposes. 35919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_None; 36019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 36119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 36219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// GetBasicInstructionClass - Determine what kind of construct V is. This is 36319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// similar to GetInstructionClass except that it only detects objc runtine 36419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// calls. This allows it to be faster. 36519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic InstructionClass GetBasicInstructionClass(const Value *V) { 36619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const CallInst *CI = dyn_cast<CallInst>(V)) { 36719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const Function *F = CI->getCalledFunction()) 36819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return GetFunctionClass(F); 36919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Otherwise, be conservative. 37019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_CallOrUser; 37119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 37219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 37319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Otherwise, be conservative. 37419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IC_User; 37519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 37619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 37719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsRetain - Test if the the given class is objc_retain or 37819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// equivalent. 37919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsRetain(InstructionClass Class) { 38019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class == IC_Retain || 38119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainRV; 38219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 38319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 38419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsAutorelease - Test if the the given class is objc_autorelease or 38519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// equivalent. 38619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsAutorelease(InstructionClass Class) { 38719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class == IC_Autorelease || 38819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleaseRV; 38919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 39019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 39119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsForwarding - Test if the given class represents instructions which return 39219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// their argument verbatim. 39319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsForwarding(InstructionClass Class) { 39419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_retainBlock technically doesn't always return its argument 39519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // verbatim, but it doesn't matter for our purposes here. 39619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class == IC_Retain || 39719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainRV || 39819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_Autorelease || 39919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleaseRV || 40019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainBlock || 40119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_NoopCast; 40219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 40319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 40419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsNoopOnNull - Test if the given class represents instructions which do 40519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// nothing if passed a null pointer. 40619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsNoopOnNull(InstructionClass Class) { 40719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class == IC_Retain || 40819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainRV || 40919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_Release || 41019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_Autorelease || 41119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleaseRV || 41219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainBlock; 41319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 41419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 41519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsAlwaysTail - Test if the given class represents instructions which are 41619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// always safe to mark with the "tail" keyword. 41719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsAlwaysTail(InstructionClass Class) { 41819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // IC_RetainBlock may be given a stack argument. 41919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class == IC_Retain || 42019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainRV || 42119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_Autorelease || 42219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleaseRV; 42319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 42419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 42519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsNoThrow - Test if the given class represents instructions which are always 42619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// safe to mark with the nounwind attribute.. 42719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsNoThrow(InstructionClass Class) { 42819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_retainBlock is not nounwind because it calls user copy constructors 42919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // which could theoretically throw. 43019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Class == IC_Retain || 43119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_RetainRV || 43219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_Release || 43319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_Autorelease || 43419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleaseRV || 43519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleasepoolPush || 43619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class == IC_AutoreleasepoolPop; 43719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 43819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 43919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// EraseInstruction - Erase the given instruction. ObjC calls return their 44019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// argument verbatim, so if it's such a call and the return value has users, 44119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// replace them with the argument value. 44219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic void EraseInstruction(Instruction *CI) { 44319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *OldArg = cast<CallInst>(CI)->getArgOperand(0); 44419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 44519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Unused = CI->use_empty(); 44619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 44719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Unused) { 44819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Replace the return value with the argument. 44919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(IsForwarding(GetBasicInstructionClass(CI)) && 45019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "Can't delete non-forwarding instruction with users!"); 45119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->replaceAllUsesWith(OldArg); 45219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 45319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 45419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->eraseFromParent(); 45519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 45619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Unused) 45719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RecursivelyDeleteTriviallyDeadInstructions(OldArg); 45819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 45919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 46019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// GetUnderlyingObjCPtr - This is a wrapper around getUnderlyingObject which 46119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// also knows how to look through objc_retain and objc_autorelease calls, which 46219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// we know to return their argument verbatim. 46319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic const Value *GetUnderlyingObjCPtr(const Value *V) { 46419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (;;) { 46519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman V = GetUnderlyingObject(V); 46619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsForwarding(GetBasicInstructionClass(V))) 46719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 46819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman V = cast<CallInst>(V)->getArgOperand(0); 46919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 47019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 47119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return V; 47219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 47319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 47419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// StripPointerCastsAndObjCCalls - This is a wrapper around 47519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// Value::stripPointerCasts which also knows how to look through objc_retain 47619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// and objc_autorelease calls, which we know to return their argument verbatim. 47719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic const Value *StripPointerCastsAndObjCCalls(const Value *V) { 47819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (;;) { 47919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman V = V->stripPointerCasts(); 48019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsForwarding(GetBasicInstructionClass(V))) 48119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 48219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman V = cast<CallInst>(V)->getArgOperand(0); 48319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 48419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return V; 48519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 48619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 48719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// StripPointerCastsAndObjCCalls - This is a wrapper around 48819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// Value::stripPointerCasts which also knows how to look through objc_retain 48919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// and objc_autorelease calls, which we know to return their argument verbatim. 49019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic Value *StripPointerCastsAndObjCCalls(Value *V) { 49119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (;;) { 49219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman V = V->stripPointerCasts(); 49319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsForwarding(GetBasicInstructionClass(V))) 49419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 49519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman V = cast<CallInst>(V)->getArgOperand(0); 49619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 49719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return V; 49819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 49919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 50019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// GetObjCArg - Assuming the given instruction is one of the special calls such 50119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// as objc_retain or objc_release, return the argument value, stripped of no-op 50219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// casts and forwarding calls. 50319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic Value *GetObjCArg(Value *Inst) { 50419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StripPointerCastsAndObjCCalls(cast<CallInst>(Inst)->getArgOperand(0)); 50519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 50619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 50719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// IsObjCIdentifiedObject - This is similar to AliasAnalysis' 50819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// isObjCIdentifiedObject, except that it uses special knowledge of 50919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// ObjC conventions... 51019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool IsObjCIdentifiedObject(const Value *V) { 51119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Assume that call results and arguments have their own "provenance". 51219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Constants (including GlobalVariables) and Allocas are never 51319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // reference-counted. 51419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<CallInst>(V) || isa<InvokeInst>(V) || 51519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman isa<Argument>(V) || isa<Constant>(V) || 51619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman isa<AllocaInst>(V)) 51719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 51819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 51919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const LoadInst *LI = dyn_cast<LoadInst>(V)) { 52019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Pointer = 52119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StripPointerCastsAndObjCCalls(LI->getPointerOperand()); 52219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Pointer)) { 52319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // A constant pointer can't be pointing to an object on the heap. It may 52419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // be reference-counted, but it won't be deleted. 52519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GV->isConstant()) 52619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 52719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StringRef Name = GV->getName(); 52819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These special variables are known to hold values which are not 52919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // reference-counted pointers. 53019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Name.startswith("\01L_OBJC_SELECTOR_REFERENCES_") || 53119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Name.startswith("\01L_OBJC_CLASSLIST_REFERENCES_") || 53219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Name.startswith("\01L_OBJC_CLASSLIST_SUP_REFS_$_") || 53319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Name.startswith("\01L_OBJC_METH_VAR_NAME_") || 53419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Name.startswith("\01l_objc_msgSend_fixup_")) 53519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 53619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 53719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 53819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 53919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 54019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 54119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 54219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// FindSingleUseIdentifiedObject - This is similar to 54319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// StripPointerCastsAndObjCCalls but it stops as soon as it finds a value 54419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// with multiple uses. 54519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic const Value *FindSingleUseIdentifiedObject(const Value *Arg) { 54619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Arg->hasOneUse()) { 54719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const BitCastInst *BC = dyn_cast<BitCastInst>(Arg)) 54819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return FindSingleUseIdentifiedObject(BC->getOperand(0)); 54919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Arg)) 55019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GEP->hasAllZeroIndices()) 55119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return FindSingleUseIdentifiedObject(GEP->getPointerOperand()); 55219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsForwarding(GetBasicInstructionClass(Arg))) 55319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return FindSingleUseIdentifiedObject( 55419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<CallInst>(Arg)->getArgOperand(0)); 55519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsObjCIdentifiedObject(Arg)) 55619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return 0; 55719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Arg; 55819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 55919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 56019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we found an identifiable object but it has multiple uses, but they 56119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // are trivial uses, we can still consider this to be a single-use 56219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // value. 56319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsObjCIdentifiedObject(Arg)) { 56419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end(); 56519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UI != UE; ++UI) { 56619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const User *U = *UI; 56719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!U->use_empty() || StripPointerCastsAndObjCCalls(U) != Arg) 56819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return 0; 56919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 57019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 57119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Arg; 57219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 57319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 57419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return 0; 57519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 57619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 57719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// ModuleHasARC - Test if the given module looks interesting to run ARC 57819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// optimization on. 57919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool ModuleHasARC(const Module &M) { 58019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return 58119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_retain") || 58219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_release") || 58319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_autorelease") || 58419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_retainAutoreleasedReturnValue") || 58519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_retainBlock") || 58619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_autoreleaseReturnValue") || 58719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_autoreleasePoolPush") || 58819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_loadWeakRetained") || 58919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_loadWeak") || 59019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_destroyWeak") || 59119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_storeWeak") || 59219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_initWeak") || 59319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_moveWeak") || 59419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_copyWeak") || 59519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_retainedObject") || 59619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_unretainedObject") || 59719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedValue("objc_unretainedPointer"); 59819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 59919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 60019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 60119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// ARC AliasAnalysis. 60219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 60319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 60419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Pass.h" 60519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Analysis/AliasAnalysis.h" 60619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Analysis/Passes.h" 60719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 60819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 60919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ObjCARCAliasAnalysis - This is a simple alias analysis 61019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// implementation that uses knowledge of ARC constructs to answer queries. 61119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// 61219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// TODO: This class could be generalized to know about other ObjC-specific 61319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// tricks. Such as knowing that ivars in the non-fragile ABI are non-aliasing 61419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// even though their offsets are dynamic. 61519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class ObjCARCAliasAnalysis : public ImmutablePass, 61619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public AliasAnalysis { 61719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 61819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static char ID; // Class identification, replacement for typeinfo 61919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ObjCARCAliasAnalysis() : ImmutablePass(ID) { 62019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman initializeObjCARCAliasAnalysisPass(*PassRegistry::getPassRegistry()); 62119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 62219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 62319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman private: 62419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void initializePass() { 62519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InitializeAliasAnalysis(this); 62619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 62719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 62819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// getAdjustedAnalysisPointer - This method is used when a pass implements 62919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// an analysis interface through multiple inheritance. If needed, it 63019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// should override this to adjust the this pointer as needed for the 63119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// specified pass info. 63219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void *getAdjustedAnalysisPointer(const void *PI) { 63319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PI == &AliasAnalysis::ID) 63419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return (AliasAnalysis*)this; 63519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return this; 63619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 63719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 63819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void getAnalysisUsage(AnalysisUsage &AU) const; 63919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual AliasResult alias(const Location &LocA, const Location &LocB); 64019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal); 64119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS); 64219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual ModRefBehavior getModRefBehavior(const Function *F); 64319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual ModRefResult getModRefInfo(ImmutableCallSite CS, 64419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Location &Loc); 64519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual ModRefResult getModRefInfo(ImmutableCallSite CS1, 64619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ImmutableCallSite CS2); 64719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 64819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} // End of anonymous namespace 64919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 65019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// Register this pass... 65119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanchar ObjCARCAliasAnalysis::ID = 0; 65219bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_AG_PASS(ObjCARCAliasAnalysis, AliasAnalysis, "objc-arc-aa", 65319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "ObjC-ARC-Based Alias Analysis", false, true, false) 65419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 65519bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanImmutablePass *llvm::createObjCARCAliasAnalysisPass() { 65619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return new ObjCARCAliasAnalysis(); 65719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 65819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 65919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid 66019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { 66119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.setPreservesAll(); 66219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis::getAnalysisUsage(AU); 66319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 66419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 66519bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanAliasAnalysis::AliasResult 66619bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::alias(const Location &LocA, const Location &LocB) { 66719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 66819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::alias(LocA, LocB); 66919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 67019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // First, strip off no-ops, including ObjC-specific no-ops, and try making a 67119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // precise alias query. 67219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *SA = StripPointerCastsAndObjCCalls(LocA.Ptr); 67319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *SB = StripPointerCastsAndObjCCalls(LocB.Ptr); 67419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasResult Result = 67519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis::alias(Location(SA, LocA.Size, LocA.TBAATag), 67619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Location(SB, LocB.Size, LocB.TBAATag)); 67719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Result != MayAlias) 67819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Result; 67919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 68019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If that failed, climb to the underlying object, including climbing through 68119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // ObjC-specific no-ops, and try making an imprecise alias query. 68219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *UA = GetUnderlyingObjCPtr(SA); 68319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *UB = GetUnderlyingObjCPtr(SB); 68419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UA != SA || UB != SB) { 68519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Result = AliasAnalysis::alias(Location(UA), Location(UB)); 68619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // We can't use MustAlias or PartialAlias results here because 68719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // GetUnderlyingObjCPtr may return an offsetted pointer value. 68819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Result == NoAlias) 68919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return NoAlias; 69019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 69119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 69219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If that failed, fail. We don't need to chain here, since that's covered 69319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // by the earlier precise query. 69419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return MayAlias; 69519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 69619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 69719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 69819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::pointsToConstantMemory(const Location &Loc, 69919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool OrLocal) { 70019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 70119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal); 70219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 70319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // First, strip off no-ops, including ObjC-specific no-ops, and try making 70419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // a precise alias query. 70519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *S = StripPointerCastsAndObjCCalls(Loc.Ptr); 70619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AliasAnalysis::pointsToConstantMemory(Location(S, Loc.Size, Loc.TBAATag), 70719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OrLocal)) 70819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 70919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 71019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If that failed, climb to the underlying object, including climbing through 71119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // ObjC-specific no-ops, and try making an imprecise alias query. 71219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *U = GetUnderlyingObjCPtr(S); 71319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (U != S) 71419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::pointsToConstantMemory(Location(U), OrLocal); 71519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 71619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If that failed, fail. We don't need to chain here, since that's covered 71719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // by the earlier precise query. 71819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 71919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 72019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 72119bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanAliasAnalysis::ModRefBehavior 72219bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::getModRefBehavior(ImmutableCallSite CS) { 72319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // We have nothing to do. Just chain to the next AliasAnalysis. 72419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::getModRefBehavior(CS); 72519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 72619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 72719bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanAliasAnalysis::ModRefBehavior 72819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::getModRefBehavior(const Function *F) { 72919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 73019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::getModRefBehavior(F); 73119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 73219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (GetFunctionClass(F)) { 73319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_NoopCast: 73419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return DoesNotAccessMemory; 73519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 73619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 73719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 73819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 73919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::getModRefBehavior(F); 74019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 74119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 74219bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanAliasAnalysis::ModRefResult 74319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::getModRefInfo(ImmutableCallSite CS, const Location &Loc) { 74419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 74519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::getModRefInfo(CS, Loc); 74619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 74719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (GetBasicInstructionClass(CS.getInstruction())) { 74819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 74919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: 75019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Autorelease: 75119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleaseRV: 75219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_NoopCast: 75319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPush: 75419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutorelease: 75519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutoreleaseRV: 75619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These functions don't access any memory visible to the compiler. 75719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Note that this doesn't include objc_retainBlock, becuase it updates 75819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pointers when it copies block data. 75919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return NoModRef; 76019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 76119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 76219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 76319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 76419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::getModRefInfo(CS, Loc); 76519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 76619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 76719bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanAliasAnalysis::ModRefResult 76819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCAliasAnalysis::getModRefInfo(ImmutableCallSite CS1, 76919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ImmutableCallSite CS2) { 77019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // TODO: Theoretically we could check for dependencies between objc_* calls 77119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // and OnlyAccessesArgumentPointees calls or other well-behaved calls. 77219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AliasAnalysis::getModRefInfo(CS1, CS2); 77319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 77419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 77519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 77619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// ARC expansion. 77719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 77819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 77919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Support/InstIterator.h" 78019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Transforms/Scalar.h" 78119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 78219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 78319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ObjCARCExpand - Early ARC transformations. 78419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class ObjCARCExpand : public FunctionPass { 78519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void getAnalysisUsage(AnalysisUsage &AU) const; 78619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool doInitialization(Module &M); 78719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool runOnFunction(Function &F); 78819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 78919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Run - A flag indicating whether this optimization pass should run. 79019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Run; 79119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 79219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 79319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static char ID; 79419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ObjCARCExpand() : FunctionPass(ID) { 79519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman initializeObjCARCExpandPass(*PassRegistry::getPassRegistry()); 79619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 79719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 79819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 79919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 80019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanchar ObjCARCExpand::ID = 0; 80119bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS(ObjCARCExpand, 80219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc-arc-expand", "ObjC ARC expansion", false, false) 80319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 80419bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanPass *llvm::createObjCARCExpandPass() { 80519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return new ObjCARCExpand(); 80619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 80719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 80819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCExpand::getAnalysisUsage(AnalysisUsage &AU) const { 80919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.setPreservesCFG(); 81019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 81119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 81219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCExpand::doInitialization(Module &M) { 81319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Run = ModuleHasARC(M); 81419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 81519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 81619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 81719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCExpand::runOnFunction(Function &F) { 81819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 81919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 82019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 82119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If nothing in the Module uses ARC, don't do anything. 82219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Run) 82319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 82419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 82519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Changed = false; 82619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 82719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I) { 82819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = &*I; 82919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 83019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (GetBasicInstructionClass(Inst)) { 83119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 83219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: 83319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Autorelease: 83419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleaseRV: 83519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutorelease: 83619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutoreleaseRV: 83719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These calls return their argument verbatim, as a low-level 83819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // optimization. However, this makes high-level optimizations 83919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // harder. Undo any uses of this optimization that the front-end 84019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // emitted here. We'll redo them in a later pass. 84119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 84219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Inst->replaceAllUsesWith(cast<CallInst>(Inst)->getArgOperand(0)); 84319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 84419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 84519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 84619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 84719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 84819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 84919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Changed; 85019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 85119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 85219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 85319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// ARC optimization. 85419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 85519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 85619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: On code like this: 85719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 85819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// objc_retain(%x) 85919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// stuff_that_cannot_release() 86019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// objc_autorelease(%x) 86119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// stuff_that_cannot_release() 86219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// objc_retain(%x) 86319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// stuff_that_cannot_release() 86419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// objc_autorelease(%x) 86519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 86619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// The second retain and autorelease can be deleted. 86719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 86819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: It should be possible to delete 86919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// objc_autoreleasePoolPush and objc_autoreleasePoolPop 87019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// pairs if nothing is actually autoreleased between them. Also, autorelease 87119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// calls followed by objc_autoreleasePoolPop calls (perhaps in ObjC++ code 87219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// after inlining) can be turned into plain release calls. 87319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 87419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: Critical-edge splitting. If the optimial insertion point is 87519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// a critical edge, the current algorithm has to fail, because it doesn't 87619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// know how to split edges. It should be possible to make the optimizer 87719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// think in terms of edges, rather than blocks, and then split critical 87819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// edges on demand. 87919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 88019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: OptimizeSequences could generalized to be Interprocedural. 88119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 88219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: Recognize that a bunch of other objc runtime calls have 88319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// non-escaping arguments and non-releasing arguments, and may be 88419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// non-autoreleasing. 88519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 88619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: Sink autorelease calls as far as possible. Unfortunately we 88719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// usually can't sink them past other calls, which would be the main 88819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// case where it would be useful. 88919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 89019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: The pointer returned from objc_loadWeakRetained is retained. 89119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 89219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: Delete release+retain pairs (rare). 89319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 89419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/GlobalAlias.h" 89519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Constants.h" 89619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/LLVMContext.h" 89719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Support/ErrorHandling.h" 89819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Support/CFG.h" 89919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/ADT/PostOrderIterator.h" 90019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/ADT/Statistic.h" 90119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 90219bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumNoops, "Number of no-op objc calls eliminated"); 90319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumPartialNoops, "Number of partially no-op objc calls eliminated"); 90419bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumAutoreleases,"Number of autoreleases converted to releases"); 90519bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumRets, "Number of return value forwarding " 90619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "retain+autoreleaes eliminated"); 90719bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumRRs, "Number of retain+release paths eliminated"); 90819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumPeeps, "Number of calls peephole-optimized"); 90919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 91019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 91119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ProvenanceAnalysis - This is similar to BasicAliasAnalysis, and it 91219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// uses many of the same techniques, except it uses special ObjC-specific 91319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// reasoning about pointer relationships. 91419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class ProvenanceAnalysis { 91519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis *AA; 91619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 91719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef std::pair<const Value *, const Value *> ValuePairTy; 91819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef DenseMap<ValuePairTy, bool> CachedResultsTy; 91919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CachedResultsTy CachedResults; 92019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 92119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool relatedCheck(const Value *A, const Value *B); 92219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool relatedSelect(const SelectInst *A, const Value *B); 92319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool relatedPHI(const PHINode *A, const Value *B); 92419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 92519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Do not implement. 92619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void operator=(const ProvenanceAnalysis &); 92719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis(const ProvenanceAnalysis &); 92819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 92919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 93019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis() {} 93119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 93219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void setAA(AliasAnalysis *aa) { AA = aa; } 93319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 93419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis *getAA() const { return AA; } 93519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 93619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool related(const Value *A, const Value *B); 93719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 93819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void clear() { 93919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CachedResults.clear(); 94019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 94119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 94219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 94319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 94419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ProvenanceAnalysis::relatedSelect(const SelectInst *A, const Value *B) { 94519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the values are Selects with the same condition, we can do a more precise 94619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // check: just check for relations between the values on corresponding arms. 94719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const SelectInst *SB = dyn_cast<SelectInst>(B)) 94819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A->getCondition() == SB->getCondition()) { 94919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (related(A->getTrueValue(), SB->getTrueValue())) 95019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 95119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (related(A->getFalseValue(), SB->getFalseValue())) 95219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 95319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 95419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 95519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 95619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check both arms of the Select node individually. 95719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (related(A->getTrueValue(), B)) 95819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 95919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (related(A->getFalseValue(), B)) 96019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 96119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 96219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // The arms both checked out. 96319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 96419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 96519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 96619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ProvenanceAnalysis::relatedPHI(const PHINode *A, const Value *B) { 96719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the values are PHIs in the same block, we can do a more precise as well 96819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // as efficient check: just check for relations between the values on 96919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // corresponding edges. 97019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const PHINode *PNB = dyn_cast<PHINode>(B)) 97119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PNB->getParent() == A->getParent()) { 97219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (unsigned i = 0, e = A->getNumIncomingValues(); i != e; ++i) 97319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (related(A->getIncomingValue(i), 97419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PNB->getIncomingValueForBlock(A->getIncomingBlock(i)))) 97519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 97619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 97719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 97819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 97919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check each unique source of the PHI node against B. 98019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const Value *, 4> UniqueSrc; 98119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (unsigned i = 0, e = A->getNumIncomingValues(); i != e; ++i) { 98219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *PV1 = A->getIncomingValue(i); 98319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UniqueSrc.insert(PV1) && related(PV1, B)) 98419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 98519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 98619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 98719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // All of the arms checked out. 98819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 98919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 99019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 99119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// isStoredObjCPointer - Test if the value of P, or any value covered by its 99219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// provenance, is ever stored within the function (not counting callees). 99319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool isStoredObjCPointer(const Value *P) { 99419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const Value *, 8> Visited; 99519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<const Value *, 8> Worklist; 99619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.push_back(P); 99719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Visited.insert(P); 99819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 99919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman P = Worklist.pop_back_val(); 100019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Value::const_use_iterator UI = P->use_begin(), UE = P->use_end(); 100119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UI != UE; ++UI) { 100219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const User *Ur = *UI; 100319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<StoreInst>(Ur)) { 100419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UI.getOperandNo() == 0) 100519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // The pointer is stored. 100619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 100719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // The pointed is stored through. 100819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 100919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 101019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<CallInst>(Ur)) 101119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // The pointer is passed as an argument, ignore this. 101219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 101319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<PtrToIntInst>(P)) 101419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Assume the worst. 101519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 101619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Visited.insert(Ur)) 101719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.push_back(Ur); 101819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 101919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (!Worklist.empty()); 102019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 102119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Everything checked out. 102219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 102319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 102419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 102519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ProvenanceAnalysis::relatedCheck(const Value *A, const Value *B) { 102619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Skip past provenance pass-throughs. 102719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman A = GetUnderlyingObjCPtr(A); 102819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman B = GetUnderlyingObjCPtr(B); 102919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 103019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Quick check. 103119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A == B) 103219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 103319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 103419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Ask regular AliasAnalysis, for a first approximation. 103519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (AA->alias(A, B)) { 103619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::NoAlias: 103719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 103819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::MustAlias: 103919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::PartialAlias: 104019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 104119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::MayAlias: 104219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 104319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 104419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 104519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool AIsIdentified = IsObjCIdentifiedObject(A); 104619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool BIsIdentified = IsObjCIdentifiedObject(B); 104719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 104819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // An ObjC-Identified object can't alias a load if it is never locally stored. 104919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AIsIdentified) { 105019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (BIsIdentified) { 105119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If both pointers have provenance, they can be directly compared. 105219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A != B) 105319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 105419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 105519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<LoadInst>(B)) 105619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isStoredObjCPointer(A); 105719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 105819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 105919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (BIsIdentified && isa<LoadInst>(A)) 106019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isStoredObjCPointer(B); 106119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 106219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 106319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Special handling for PHI and Select. 106419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const PHINode *PN = dyn_cast<PHINode>(A)) 106519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return relatedPHI(PN, B); 106619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const PHINode *PN = dyn_cast<PHINode>(B)) 106719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return relatedPHI(PN, A); 106819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const SelectInst *S = dyn_cast<SelectInst>(A)) 106919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return relatedSelect(S, B); 107019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const SelectInst *S = dyn_cast<SelectInst>(B)) 107119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return relatedSelect(S, A); 107219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 107319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Conservative. 107419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 107519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 107619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 107719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ProvenanceAnalysis::related(const Value *A, const Value *B) { 107819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Begin by inserting a conservative value into the map. If the insertion 107919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // fails, we have the answer already. If it succeeds, leave it there until we 108019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // compute the real answer to guard against recursive queries. 108119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A > B) std::swap(A, B); 108219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<CachedResultsTy::iterator, bool> Pair = 108319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CachedResults.insert(std::make_pair(ValuePairTy(A, B), true)); 108419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Pair.second) 108519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Pair.first->second; 108619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 108719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Result = relatedCheck(A, B); 108819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CachedResults[ValuePairTy(A, B)] = Result; 108919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Result; 109019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 109119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 109219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 109319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Sequence - A sequence of states that a pointer may go through in which an 109419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_retain and objc_release are actually needed. 109519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman enum Sequence { 109619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_None, 109719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_Retain, ///< objc_retain(x) 109819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_CanRelease, ///< foo(x) -- x could possibly see a ref count decrement 109919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_Use, ///< any use of x 110019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_Stop, ///< like S_Release, but code motion is stopped 110119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_Release, ///< objc_release(x) 110219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S_MovableRelease ///< objc_release(x), !clang.imprecise_release 110319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 110419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 110519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 110619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic Sequence MergeSeqs(Sequence A, Sequence B, bool TopDown) { 110719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // The easy cases. 110819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A == B) 110919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return A; 111019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A == S_None || B == S_None) 111119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return S_None; 111219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 111319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A > B) std::swap(A, B); 111419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (TopDown) { 111519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Choose the side which is further along in the sequence. 111619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if ((A == S_Retain || A == S_CanRelease) && 111719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (B == S_CanRelease || B == S_Use)) 111819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return B; 111919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 112019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Choose the side which is further along in the sequence. 112119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if ((A == S_Use || A == S_CanRelease) && 112219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (B == S_Use || B == S_Release || B == S_Stop || B == S_MovableRelease)) 112319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return A; 112419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If both sides are releases, choose the more conservative one. 112519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A == S_Stop && (B == S_Release || B == S_MovableRelease)) 112619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return A; 112719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (A == S_Release && B == S_MovableRelease) 112819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return A; 112919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 113019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 113119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return S_None; 113219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 113319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 113419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 113519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// RRInfo - Unidirectional information about either a 113619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// retain-decrement-use-release sequence or release-use-decrement-retain 113719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// reverese sequence. 113819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman struct RRInfo { 113919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// KnownSafe - After an objc_retain, the reference count of the referenced 114019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// object is known to be positive. Similarly, before an objc_release, the 114119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// reference count of the referenced object is known to be positive. If 114219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// there are retain-release pairs in code regions where the retain count 114319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// is known to be positive, they can be eliminated, regardless of any side 114419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// effects between them. 114519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// 114619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Also, a retain+release pair nested within another retain+release 114719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// pair all on the known same pointer value can be eliminated, regardless 114819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// of any intervening side effects. 114919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// 115019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// KnownSafe is true when either of these conditions is satisfied. 115119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool KnownSafe; 115219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 115319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// IsRetainBlock - True if the Calls are objc_retainBlock calls (as 115419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// opposed to objc_retain calls). 115519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool IsRetainBlock; 115619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 115719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// IsTailCallRelease - True of the objc_release calls are all marked 115819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// with the "tail" keyword. 115919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool IsTailCallRelease; 116019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 116119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ReleaseMetadata - If the Calls are objc_release calls and they all have 116219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// a clang.imprecise_release tag, this is the metadata tag. 116319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MDNode *ReleaseMetadata; 116419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 116519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Calls - For a top-down sequence, the set of objc_retains or 116619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// objc_retainBlocks. For bottom-up, the set of objc_releases. 116719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 2> Calls; 116819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 116919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ReverseInsertPts - The set of optimal insert positions for 117019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// moving calls in the opposite sequence. 117119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 2> ReverseInsertPts; 117219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 117319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRInfo() : 117419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman KnownSafe(false), IsRetainBlock(false), IsTailCallRelease(false), 117519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleaseMetadata(0) {} 117619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 117719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void clear(); 117819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 117919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 118019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 118119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid RRInfo::clear() { 118219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman KnownSafe = false; 118319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IsRetainBlock = false; 118419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IsTailCallRelease = false; 118519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleaseMetadata = 0; 118619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Calls.clear(); 118719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReverseInsertPts.clear(); 118819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 118919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 119019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 119119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// PtrState - This class summarizes several per-pointer runtime properties 119219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// which are propogated through the flow graph. 119319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class PtrState { 119419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// RefCount - The known minimum number of reference count increments. 119519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned RefCount; 119619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 119719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// NestCount - The known minimum level of retain+release nesting. 119819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned NestCount; 119919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 120019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Seq - The current position in the sequence. 120119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Sequence Seq; 120219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 120319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 120419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// RRI - Unidirectional information about the current sequence. 120519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// TODO: Encapsulate this better. 120619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRInfo RRI; 120719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 120819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState() : RefCount(0), NestCount(0), Seq(S_None) {} 120919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 121019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void SetAtLeastOneRefCount() { 121119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RefCount == 0) RefCount = 1; 121219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 121319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 121419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void IncrementRefCount() { 121519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RefCount != UINT_MAX) ++RefCount; 121619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 121719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 121819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void DecrementRefCount() { 121919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RefCount != 0) --RefCount; 122019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 122119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 122219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool IsKnownIncremented() const { 122319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return RefCount > 0; 122419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 122519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 122619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void IncrementNestCount() { 122719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NestCount != UINT_MAX) ++NestCount; 122819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 122919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 123019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void DecrementNestCount() { 123119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NestCount != 0) --NestCount; 123219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 123319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 123419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool IsKnownNested() const { 123519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return NestCount > 0; 123619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 123719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 123819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void SetSeq(Sequence NewSeq) { 123919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Seq = NewSeq; 124019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 124119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 124219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void SetSeqToRelease(MDNode *M) { 124319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Seq == S_None || Seq == S_Use) { 124419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Seq = M ? S_MovableRelease : S_Release; 124519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.ReleaseMetadata = M; 124619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else if (Seq != S_MovableRelease || RRI.ReleaseMetadata != M) { 124719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Seq = S_Release; 124819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.ReleaseMetadata = 0; 124919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 125019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 125119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 125219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Sequence GetSeq() const { 125319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Seq; 125419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 125519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 125619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void ClearSequenceProgress() { 125719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Seq = S_None; 125819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.clear(); 125919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 126019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 126119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void Merge(const PtrState &Other, bool TopDown); 126219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 126319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 126419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 126519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid 126619bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanPtrState::Merge(const PtrState &Other, bool TopDown) { 126719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Seq = MergeSeqs(Seq, Other.Seq, TopDown); 126819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RefCount = std::min(RefCount, Other.RefCount); 126919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NestCount = std::min(NestCount, Other.NestCount); 127019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 127119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // We can't merge a plain objc_retain with an objc_retainBlock. 127219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RRI.IsRetainBlock != Other.RRI.IsRetainBlock) 127319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Seq = S_None; 127419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 127519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Seq == S_None) { 127619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.clear(); 127719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 127819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Conservatively merge the ReleaseMetadata information. 127919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RRI.ReleaseMetadata != Other.RRI.ReleaseMetadata) 128019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.ReleaseMetadata = 0; 128119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 128219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.KnownSafe = RRI.KnownSafe && Other.RRI.KnownSafe; 128319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.IsTailCallRelease = RRI.IsTailCallRelease && Other.RRI.IsTailCallRelease; 128419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.Calls.insert(Other.RRI.Calls.begin(), Other.RRI.Calls.end()); 128519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRI.ReverseInsertPts.insert(Other.RRI.ReverseInsertPts.begin(), 128619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Other.RRI.ReverseInsertPts.end()); 128719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 128819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 128919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 129019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 129119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// BBState - Per-BasicBlock state. 129219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class BBState { 129319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// TopDownPathCount - The number of unique control paths from the entry 129419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// which can reach this block. 129519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned TopDownPathCount; 129619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 129719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// BottomUpPathCount - The number of unique control paths to exits 129819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// from this block. 129919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned BottomUpPathCount; 130019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 130119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// MapTy - A type for PerPtrTopDown and PerPtrBottomUp. 130219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef MapVector<const Value *, PtrState> MapTy; 130319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 130419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// PerPtrTopDown - The top-down traversal uses this to record information 130519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// known about a pointer at the bottom of each block. 130619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapTy PerPtrTopDown; 130719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 130819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// PerPtrBottomUp - The bottom-up traversal uses this to record information 130919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// known about a pointer at the top of each block. 131019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapTy PerPtrBottomUp; 131119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 131219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 131319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBState() : TopDownPathCount(0), BottomUpPathCount(0) {} 131419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 131519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef MapTy::iterator ptr_iterator; 131619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef MapTy::const_iterator ptr_const_iterator; 131719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 131819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_iterator top_down_ptr_begin() { return PerPtrTopDown.begin(); } 131919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_iterator top_down_ptr_end() { return PerPtrTopDown.end(); } 132019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_const_iterator top_down_ptr_begin() const { 132119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerPtrTopDown.begin(); 132219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 132319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_const_iterator top_down_ptr_end() const { 132419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerPtrTopDown.end(); 132519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 132619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 132719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_iterator bottom_up_ptr_begin() { return PerPtrBottomUp.begin(); } 132819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_iterator bottom_up_ptr_end() { return PerPtrBottomUp.end(); } 132919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_const_iterator bottom_up_ptr_begin() const { 133019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerPtrBottomUp.begin(); 133119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 133219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ptr_const_iterator bottom_up_ptr_end() const { 133319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerPtrBottomUp.end(); 133419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 133519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 133619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// SetAsEntry - Mark this block as being an entry block, which has one 133719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// path from the entry by definition. 133819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void SetAsEntry() { TopDownPathCount = 1; } 133919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 134019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// SetAsExit - Mark this block as being an exit block, which has one 134119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// path to an exit by definition. 134219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void SetAsExit() { BottomUpPathCount = 1; } 134319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 134419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &getPtrTopDownState(const Value *Arg) { 134519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerPtrTopDown[Arg]; 134619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 134719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 134819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &getPtrBottomUpState(const Value *Arg) { 134919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerPtrBottomUp[Arg]; 135019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 135119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 135219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void clearBottomUpPointers() { 135319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PerPtrBottomUp.clear(); 135419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 135519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 135619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void clearTopDownPointers() { 135719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PerPtrTopDown.clear(); 135819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 135919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 136019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void InitFromPred(const BBState &Other); 136119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void InitFromSucc(const BBState &Other); 136219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void MergePred(const BBState &Other); 136319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void MergeSucc(const BBState &Other); 136419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 136519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// GetAllPathCount - Return the number of possible unique paths from an 136619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// entry to an exit which pass through this block. This is only valid 136719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// after both the top-down and bottom-up traversals are complete. 136819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned GetAllPathCount() const { 136919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return TopDownPathCount * BottomUpPathCount; 137019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 137119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 137219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// IsVisitedTopDown - Test whether the block for this BBState has been 137319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// visited by the top-down portion of the algorithm. 137419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool isVisitedTopDown() const { 137519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return TopDownPathCount != 0; 137619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 137719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 137819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 137919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 138019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid BBState::InitFromPred(const BBState &Other) { 138119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PerPtrTopDown = Other.PerPtrTopDown; 138219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman TopDownPathCount = Other.TopDownPathCount; 138319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 138419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 138519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid BBState::InitFromSucc(const BBState &Other) { 138619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PerPtrBottomUp = Other.PerPtrBottomUp; 138719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BottomUpPathCount = Other.BottomUpPathCount; 138819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 138919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 139019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// MergePred - The top-down traversal uses this to merge information about 139119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// predecessors to form the initial state for a new block. 139219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid BBState::MergePred(const BBState &Other) { 139319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Other.TopDownPathCount can be 0, in which case it is either dead or a 139419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // loop backedge. Loop backedges are special. 139519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman TopDownPathCount += Other.TopDownPathCount; 139619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 139719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For each entry in the other set, if our set has an entry with the same key, 139819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // merge the entries. Otherwise, copy the entry and merge it with an empty 139919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // entry. 140019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ptr_const_iterator MI = Other.top_down_ptr_begin(), 140119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ME = Other.top_down_ptr_end(); MI != ME; ++MI) { 140219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<ptr_iterator, bool> Pair = PerPtrTopDown.insert(*MI); 140319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Pair.first->second.Merge(Pair.second ? PtrState() : MI->second, 140419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /*TopDown=*/true); 140519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 140619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 140719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For each entry in our set, if the other set doesn't have an entry with the 140819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // same key, force it to merge with an empty entry. 140919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ptr_iterator MI = top_down_ptr_begin(), 141019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ME = top_down_ptr_end(); MI != ME; ++MI) 141119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Other.PerPtrTopDown.find(MI->first) == Other.PerPtrTopDown.end()) 141219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MI->second.Merge(PtrState(), /*TopDown=*/true); 141319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 141419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 141519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// MergeSucc - The bottom-up traversal uses this to merge information about 141619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// successors to form the initial state for a new block. 141719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid BBState::MergeSucc(const BBState &Other) { 141819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Other.BottomUpPathCount can be 0, in which case it is either dead or a 141919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // loop backedge. Loop backedges are special. 142019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BottomUpPathCount += Other.BottomUpPathCount; 142119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 142219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For each entry in the other set, if our set has an entry with the 142319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // same key, merge the entries. Otherwise, copy the entry and merge 142419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // it with an empty entry. 142519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ptr_const_iterator MI = Other.bottom_up_ptr_begin(), 142619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ME = Other.bottom_up_ptr_end(); MI != ME; ++MI) { 142719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<ptr_iterator, bool> Pair = PerPtrBottomUp.insert(*MI); 142819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Pair.first->second.Merge(Pair.second ? PtrState() : MI->second, 142919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /*TopDown=*/false); 143019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 143119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 143219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For each entry in our set, if the other set doesn't have an entry 143319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // with the same key, force it to merge with an empty entry. 143419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ptr_iterator MI = bottom_up_ptr_begin(), 143519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ME = bottom_up_ptr_end(); MI != ME; ++MI) 143619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Other.PerPtrBottomUp.find(MI->first) == Other.PerPtrBottomUp.end()) 143719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MI->second.Merge(PtrState(), /*TopDown=*/false); 143819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 143919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 144019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 144119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ObjCARCOpt - The main ARC optimization pass. 144219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class ObjCARCOpt : public FunctionPass { 144319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Changed; 144419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis PA; 144519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 144619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Run - A flag indicating whether this optimization pass should run. 144719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Run; 144819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 144919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// RetainRVCallee, etc. - Declarations for ObjC runtime 145019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// functions, for use in creating calls to them. These are initialized 145119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// lazily to avoid cluttering up the Module with unused declarations. 145219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *RetainRVCallee, *AutoreleaseRVCallee, *ReleaseCallee, 145319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman *RetainCallee, *RetainBlockCallee, *AutoreleaseCallee; 145419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 145519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// UsedInThisFunciton - Flags which determine whether each of the 145619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// interesting runtine functions is in fact used in the current function. 145719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned UsedInThisFunction; 145819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 145919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ImpreciseReleaseMDKind - The Metadata Kind for clang.imprecise_release 146019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// metadata. 146119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned ImpreciseReleaseMDKind; 146219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 146319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getRetainRVCallee(Module *M); 146419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getAutoreleaseRVCallee(Module *M); 146519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getReleaseCallee(Module *M); 146619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getRetainCallee(Module *M); 146719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getRetainBlockCallee(Module *M); 146819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getAutoreleaseCallee(Module *M); 146919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 147019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void OptimizeRetainCall(Function &F, Instruction *Retain); 147119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool OptimizeRetainRVCall(Function &F, Instruction *RetainRV); 147219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV); 147319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void OptimizeIndividualCalls(Function &F); 147419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 147519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void CheckForCFGHazards(const BasicBlock *BB, 147619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 147719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBState &MyStates) const; 147819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool VisitBottomUp(BasicBlock *BB, 147919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 148019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains); 148119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool VisitTopDown(BasicBlock *BB, 148219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 148319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases); 148419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Visit(Function &F, 148519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 148619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains, 148719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases); 148819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 148919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void MoveCalls(Value *Arg, RRInfo &RetainsToMove, RRInfo &ReleasesToMove, 149019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains, 149119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases, 149219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVectorImpl<Instruction *> &DeadInsts, 149319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Module *M); 149419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 149519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool PerformCodePlacement(DenseMap<const BasicBlock *, BBState> &BBStates, 149619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains, 149719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases, 149819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Module *M); 149919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 150019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void OptimizeWeakCalls(Function &F); 150119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 150219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool OptimizeSequences(Function &F); 150319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 150419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void OptimizeReturns(Function &F); 150519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 150619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void getAnalysisUsage(AnalysisUsage &AU) const; 150719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool doInitialization(Module &M); 150819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool runOnFunction(Function &F); 150919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void releaseMemory(); 151019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 151119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 151219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static char ID; 151319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ObjCARCOpt() : FunctionPass(ID) { 151419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman initializeObjCARCOptPass(*PassRegistry::getPassRegistry()); 151519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 151619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 151719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 151819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 151919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanchar ObjCARCOpt::ID = 0; 152019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS_BEGIN(ObjCARCOpt, 152119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc-arc", "ObjC ARC optimization", false, false) 152219bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS_DEPENDENCY(ObjCARCAliasAnalysis) 152319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS_END(ObjCARCOpt, 152419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc-arc", "ObjC ARC optimization", false, false) 152519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 152619bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanPass *llvm::createObjCARCOptPass() { 152719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return new ObjCARCOpt(); 152819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 152919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 153019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCOpt::getAnalysisUsage(AnalysisUsage &AU) const { 153119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.addRequired<ObjCARCAliasAnalysis>(); 153219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.addRequired<AliasAnalysis>(); 153319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // ARC optimization doesn't currently split critical edges. 153419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.setPreservesCFG(); 153519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 153619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 153719bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCOpt::getRetainRVCallee(Module *M) { 153819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainRVCallee) { 153919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 154019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); 154119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 154219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(I8X); 154319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType *FTy = 154419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(I8X, Params, /*isVarArg=*/false); 154519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 154619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 154719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainRVCallee = 154819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction("objc_retainAutoreleasedReturnValue", FTy, 154919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 155019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 155119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return RetainRVCallee; 155219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 155319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 155419bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCOpt::getAutoreleaseRVCallee(Module *M) { 155519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!AutoreleaseRVCallee) { 155619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 155719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); 155819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 155919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(I8X); 156019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType *FTy = 156119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(I8X, Params, /*isVarArg=*/false); 156219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 156319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 156419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AutoreleaseRVCallee = 156519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction("objc_autoreleaseReturnValue", FTy, 156619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 156719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 156819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AutoreleaseRVCallee; 156919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 157019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 157119bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCOpt::getReleaseCallee(Module *M) { 157219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!ReleaseCallee) { 157319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 157419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 157519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C))); 157619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 157719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 157819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleaseCallee = 157919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction( 158019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc_release", 158119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(Type::getVoidTy(C), Params, /*isVarArg=*/false), 158219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 158319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 158419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return ReleaseCallee; 158519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 158619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 158719bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCOpt::getRetainCallee(Module *M) { 158819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainCallee) { 158919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 159019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 159119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C))); 159219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 159319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 159419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainCallee = 159519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction( 159619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc_retain", 159719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(Params[0], Params, /*isVarArg=*/false), 159819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 159919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 160019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return RetainCallee; 160119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 160219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 160319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCOpt::getRetainBlockCallee(Module *M) { 160419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainBlockCallee) { 160519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 160619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 160719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C))); 160819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 160919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_retainBlock is not nounwind because it calls user copy constructors 161019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // which could theoretically throw. 161119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainBlockCallee = 161219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction( 161319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc_retainBlock", 161419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(Params[0], Params, /*isVarArg=*/false), 161519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 161619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 161719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return RetainBlockCallee; 161819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 161919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 162019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCOpt::getAutoreleaseCallee(Module *M) { 162119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!AutoreleaseCallee) { 162219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 162319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 162419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C))); 162519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 162619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 162719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AutoreleaseCallee = 162819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction( 162919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc_autorelease", 163019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(Params[0], Params, /*isVarArg=*/false), 163119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 163219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 163319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AutoreleaseCallee; 163419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 163519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 163619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// CanAlterRefCount - Test whether the given instruction can result in a 163719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// reference count modification (positive or negative) for the pointer's 163819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// object. 163919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool 164019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanCanAlterRefCount(const Instruction *Inst, const Value *Ptr, 164119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis &PA, InstructionClass Class) { 164219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 164319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Autorelease: 164419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleaseRV: 164519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_User: 164619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These operations never directly modify a reference count. 164719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 164819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: break; 164919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 165019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 165119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ImmutableCallSite CS = static_cast<const Value *>(Inst); 165219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(CS && "Only calls can alter reference counts!"); 165319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 165419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // See if AliasAnalysis can help us with the call. 165519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis::ModRefBehavior MRB = PA.getAA()->getModRefBehavior(CS); 165619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AliasAnalysis::onlyReadsMemory(MRB)) 165719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 165819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AliasAnalysis::onlyAccessesArgPointees(MRB)) { 165919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ImmutableCallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 166019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman I != E; ++I) { 166119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Op = *I; 166219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(Op) && PA.related(Ptr, Op)) 166319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 166419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 166519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 166619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 166719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 166819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Assume the worst. 166919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 167019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 167119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 167219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// CanUse - Test whether the given instruction can "use" the given pointer's 167319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// object in a way that requires the reference count to be positive. 167419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool 167519bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanCanUse(const Instruction *Inst, const Value *Ptr, ProvenanceAnalysis &PA, 167619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class) { 167719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // IC_Call operations (as opposed to IC_CallOrUser) never "use" objc pointers. 167819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_Call) 167919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 168019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 168119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Consider various instructions which may have pointer arguments which are 168219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // not "uses". 168319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const ICmpInst *ICI = dyn_cast<ICmpInst>(Inst)) { 168419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Comparing a pointer with null, or any other constant, isn't really a use, 168519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // because we don't care what the pointer points to, or about the values 168619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // of any other dynamic reference-counted pointers. 168719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsPotentialUse(ICI->getOperand(1))) 168819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 168919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else if (ImmutableCallSite CS = static_cast<const Value *>(Inst)) { 169019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For calls, just check the arguments (and not the callee operand). 169119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (ImmutableCallSite::arg_iterator OI = CS.arg_begin(), 169219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OE = CS.arg_end(); OI != OE; ++OI) { 169319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Op = *OI; 169419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(Op) && PA.related(Ptr, Op)) 169519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 169619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 169719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 169819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else if (const StoreInst *SI = dyn_cast<StoreInst>(Inst)) { 169919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Special-case stores, because we don't care about the stored value, just 170019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // the store address. 170119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Op = GetUnderlyingObjCPtr(SI->getPointerOperand()); 170219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we can't tell what the underlying object was, assume there is a 170319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // dependence. 170419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return IsPotentialUse(Op) && PA.related(Op, Ptr); 170519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 170619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 170719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check each operand for a match. 170819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (User::const_op_iterator OI = Inst->op_begin(), OE = Inst->op_end(); 170919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OI != OE; ++OI) { 171019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Op = *OI; 171119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsPotentialUse(Op) && PA.related(Ptr, Op)) 171219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 171319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 171419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 171519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 171619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 171719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// CanInterruptRV - Test whether the given instruction can autorelease 171819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// any pointer or cause an autoreleasepool pop. 171919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool 172019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanCanInterruptRV(InstructionClass Class) { 172119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 172219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPop: 172319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_CallOrUser: 172419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Call: 172519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Autorelease: 172619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleaseRV: 172719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutorelease: 172819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutoreleaseRV: 172919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 173019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 173119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 173219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 173319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 173419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 173519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 173619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// DependenceKind - There are several kinds of dependence-like concepts in 173719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// use here. 173819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman enum DependenceKind { 173919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NeedsPositiveRetainCount, 174019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CanChangeRetainCount, 174119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainAutoreleaseDep, ///< Blocks objc_retainAutorelease. 174219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainAutoreleaseRVDep, ///< Blocks objc_retainAutoreleaseReturnValue. 174319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainRVDep ///< Blocks objc_retainAutoreleasedReturnValue. 174419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 174519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 174619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 174719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// Depends - Test if there can be dependencies on Inst through Arg. This 174819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// function only tests dependencies relevant for removing pairs of calls. 174919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool 175019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanDepends(DependenceKind Flavor, Instruction *Inst, const Value *Arg, 175119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis &PA) { 175219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we've reached the definition of Arg, stop. 175319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Inst == Arg) 175419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 175519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 175619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Flavor) { 175719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case NeedsPositiveRetainCount: { 175819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetInstructionClass(Inst); 175919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 176019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPop: 176119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPush: 176219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_None: 176319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 176419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 176519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return CanUse(Inst, Arg, PA, Class); 176619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 176719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 176819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 176919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case CanChangeRetainCount: { 177019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetInstructionClass(Inst); 177119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 177219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPop: 177319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Conservatively assume this can decrement any count. 177419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 177519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPush: 177619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_None: 177719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 177819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 177919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return CanAlterRefCount(Inst, Arg, PA, Class); 178019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 178119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 178219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 178319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case RetainAutoreleaseDep: 178419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (GetBasicInstructionClass(Inst)) { 178519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPop: 178619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Don't merge an objc_autorelease with an objc_retain inside a different 178719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // autoreleasepool scope. 178819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 178919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 179019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: 179119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for a retain of the same pointer for merging. 179219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return GetObjCArg(Inst) == Arg; 179319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 179419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Nothing else matters for objc_retainAutorelease formation. 179519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 179619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 179719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 179819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 179919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case RetainAutoreleaseRVDep: { 180019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetBasicInstructionClass(Inst); 180119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 180219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 180319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: 180419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for a retain of the same pointer for merging. 180519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return GetObjCArg(Inst) == Arg; 180619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 180719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Anything that can autorelease interrupts 180819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // retainAutoreleaseReturnValue formation. 180919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return CanInterruptRV(Class); 181019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 181119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 181219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 181319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 181419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case RetainRVDep: 181519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return CanInterruptRV(GetBasicInstructionClass(Inst)); 181619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 181719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 181819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("Invalid dependence flavor"); 181919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 182019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 182119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 182219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// FindDependencies - Walk up the CFG from StartPos (which is in StartBB) and 182319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// find local and non-local dependencies on Arg. 182419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// TODO: Cache results? 182519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic void 182619bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanFindDependencies(DependenceKind Flavor, 182719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg, 182819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *StartBB, Instruction *StartInst, 182919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 4> &DependingInstructions, 183019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const BasicBlock *, 4> &Visited, 183119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis &PA) { 183219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator StartPos = StartInst; 183319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 183419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<std::pair<BasicBlock *, BasicBlock::iterator>, 4> Worklist; 183519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.push_back(std::make_pair(StartBB, StartPos)); 183619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 183719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<BasicBlock *, BasicBlock::iterator> Pair = 183819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.pop_back_val(); 183919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *LocalStartBB = Pair.first; 184019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator LocalStartPos = Pair.second; 184119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator StartBBBegin = LocalStartBB->begin(); 184219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (;;) { 184319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (LocalStartPos == StartBBBegin) { 184419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman pred_iterator PI(LocalStartBB), PE(LocalStartBB, false); 184519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PI == PE) 184619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we've reached the function entry, produce a null dependence. 184719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.insert(0); 184819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else 184919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Add the predecessors to the worklist. 185019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 185119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *PredBB = *PI; 185219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Visited.insert(PredBB)) 185319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.push_back(std::make_pair(PredBB, PredBB->end())); 185419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (++PI != PE); 185519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 185619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 185719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 185819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = --LocalStartPos; 185919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Depends(Flavor, Inst, Arg, PA)) { 186019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.insert(Inst); 186119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 186219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 186319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 186419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (!Worklist.empty()); 186519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 186619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Determine whether the original StartBB post-dominates all of the blocks we 186719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // visited. If not, insert a sentinal indicating that most optimizations are 186819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // not safe. 186919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<const BasicBlock *, 4>::const_iterator I = Visited.begin(), 187019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman E = Visited.end(); I != E; ++I) { 187119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const BasicBlock *BB = *I; 187219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (BB == StartBB) 187319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 187419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const TerminatorInst *TI = cast<TerminatorInst>(&BB->back()); 187519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (succ_const_iterator SI(TI), SE(TI, false); SI != SE; ++SI) { 187619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const BasicBlock *Succ = *SI; 187719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Succ != StartBB && !Visited.count(Succ)) { 187819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.insert(reinterpret_cast<Instruction *>(-1)); 187919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return; 188019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 188119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 188219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 188319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 188419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 188519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool isNullOrUndef(const Value *V) { 188619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa<ConstantPointerNull>(V) || isa<UndefValue>(V); 188719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 188819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 188919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstatic bool isNoopInstruction(const Instruction *I) { 189019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa<BitCastInst>(I) || 189119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (isa<GetElementPtrInst>(I) && 189219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<GetElementPtrInst>(I)->hasAllZeroIndices()); 189319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 189419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 189519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeRetainCall - Turn objc_retain into 189619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// objc_retainAutoreleasedReturnValue if the operand is a return value. 189719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid 189819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::OptimizeRetainCall(Function &F, Instruction *Retain) { 189919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallSite CS(GetObjCArg(Retain)); 190019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Call = CS.getInstruction(); 190119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Call) return; 190219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Call->getParent() != Retain->getParent()) return; 190319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 190419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that the call is next to the retain. 190519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator I = Call; 190619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++I; 190719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (isNoopInstruction(I)) ++I; 190819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (&*I != Retain) 190919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return; 191019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 191119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Turn it to an objc_retainAutoreleasedReturnValue.. 191219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 191319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumPeeps; 191419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<CallInst>(Retain)->setCalledFunction(getRetainRVCallee(F.getParent())); 191519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 191619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 191719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeRetainRVCall - Turn objc_retainAutoreleasedReturnValue into 191819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// objc_retain if the operand is not a return value. Or, if it can be 191919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// paired with an objc_autoreleaseReturnValue, delete the pair and 192019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// return true. 192119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 192219bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::OptimizeRetainRVCall(Function &F, Instruction *RetainRV) { 192319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for the argument being from an immediately preceding call. 192419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Arg = GetObjCArg(RetainRV); 192519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallSite CS(Arg); 192619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Instruction *Call = CS.getInstruction()) 192719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Call->getParent() == RetainRV->getParent()) { 192819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator I = Call; 192919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++I; 193019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (isNoopInstruction(I)) ++I; 193119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (&*I == RetainRV) 193219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 193319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 193419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 193519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for being preceded by an objc_autoreleaseReturnValue on the same 193619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pointer. In this case, we can delete the pair. 193719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator I = RetainRV, Begin = RetainRV->getParent()->begin(); 193819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (I != Begin) { 193919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do --I; while (I != Begin && isNoopInstruction(I)); 194019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GetBasicInstructionClass(I) == IC_AutoreleaseRV && 194119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman GetObjCArg(I) == Arg) { 194219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 194319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumPeeps; 194419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(I); 194519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(RetainRV); 194619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 194719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 194819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 194919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 195019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Turn it to a plain objc_retain. 195119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 195219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumPeeps; 195319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<CallInst>(RetainRV)->setCalledFunction(getRetainCallee(F.getParent())); 195419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 195519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 195619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 195719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeAutoreleaseRVCall - Turn objc_autoreleaseReturnValue into 195819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// objc_autorelease if the result is not used as a return value. 195919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid 196019bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV) { 196119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for a return of the pointer value. 196219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Ptr = GetObjCArg(AutoreleaseRV); 196319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<const Value *, 2> Users; 196419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Users.push_back(Ptr); 196519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 196619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Ptr = Users.pop_back_val(); 196719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end(); 196819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UI != UE; ++UI) { 196919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const User *I = *UI; 197019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<ReturnInst>(I) || GetBasicInstructionClass(I) == IC_RetainRV) 197119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return; 197219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isa<BitCastInst>(I)) 197319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Users.push_back(I); 197419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 197519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (!Users.empty()); 197619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 197719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 197819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumPeeps; 197919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<CallInst>(AutoreleaseRV)-> 198019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman setCalledFunction(getAutoreleaseCallee(F.getParent())); 198119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 198219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 198319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeIndividualCalls - Visit each call, one at a time, and make 198419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// simplifications without doing any additional analysis. 198519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCOpt::OptimizeIndividualCalls(Function &F) { 198619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Reset all the flags in preparation for recomputing them. 198719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UsedInThisFunction = 0; 198819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 198919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Visit all objc_* calls in F. 199019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ) { 199119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = &*I++; 199219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetBasicInstructionClass(Inst); 199319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 199419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 199519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: break; 199619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 199719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Delete no-op casts. These function calls have special semantics, but 199819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // the semantics are entirely implemented via lowering in the front-end, 199919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // so by the time they reach the optimizer, they are just no-op calls 200019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // which return their argument. 200119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // 200219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // There are gray areas here, as the ability to cast reference-counted 200319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pointers to raw void* and back allows code to break ARC assumptions, 200419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // however these are currently considered to be unimportant. 200519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_NoopCast: 200619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 200719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumNoops; 200819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Inst); 200919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 201019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 201119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the pointer-to-weak-pointer is null, it's undefined behavior. 201219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_StoreWeak: 201319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_LoadWeak: 201419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_LoadWeakRetained: 201519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_InitWeak: 201619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_DestroyWeak: { 201719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *CI = cast<CallInst>(Inst); 201819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isNullOrUndef(CI->getArgOperand(0))) { 201919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *Ty = CI->getArgOperand(0)->getType(); 202019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman new StoreInst(UndefValue::get(cast<PointerType>(Ty)->getElementType()), 202119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant::getNullValue(Ty), 202219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI); 202319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->replaceAllUsesWith(UndefValue::get(CI->getType())); 202419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->eraseFromParent(); 202519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 202619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 202719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 202819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 202919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_CopyWeak: 203019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_MoveWeak: { 203119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *CI = cast<CallInst>(Inst); 203219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isNullOrUndef(CI->getArgOperand(0)) || 203319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman isNullOrUndef(CI->getArgOperand(1))) { 203419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *Ty = CI->getArgOperand(0)->getType(); 203519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman new StoreInst(UndefValue::get(cast<PointerType>(Ty)->getElementType()), 203619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant::getNullValue(Ty), 203719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI); 203819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->replaceAllUsesWith(UndefValue::get(CI->getType())); 203919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->eraseFromParent(); 204019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 204119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 204219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 204319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 204419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 204519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OptimizeRetainCall(F, Inst); 204619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 204719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: 204819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (OptimizeRetainRVCall(F, Inst)) 204919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 205019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 205119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleaseRV: 205219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OptimizeAutoreleaseRVCall(F, Inst); 205319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 205419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 205519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 205619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_autorelease(x) -> objc_release(x) if x is otherwise unused. 205719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsAutorelease(Class) && Inst->use_empty()) { 205819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = cast<CallInst>(Inst); 205919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = Call->getArgOperand(0); 206019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = FindSingleUseIdentifiedObject(Arg); 206119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Arg) { 206219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 206319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumAutoreleases; 206419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 206519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Create the declaration lazily. 206619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = Inst->getContext(); 206719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *NewCall = 206819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst::Create(getReleaseCallee(F.getParent()), 206919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->getArgOperand(0), "", Call); 207019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewCall->setMetadata(ImpreciseReleaseMDKind, 207119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MDNode::get(C, ArrayRef<Value *>())); 207219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Call); 207319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Inst = NewCall; 207419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Class = IC_Release; 207519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 207619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 207719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 207819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For functions which can never be passed stack arguments, add 207919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // a tail keyword. 208019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsAlwaysTail(Class)) { 208119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 208219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<CallInst>(Inst)->setTailCall(); 208319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 208419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 208519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Set nounwind as needed. 208619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (IsNoThrow(Class)) { 208719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 208819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<CallInst>(Inst)->setDoesNotThrow(); 208919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 209019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 209119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsNoopOnNull(Class)) { 209219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UsedInThisFunction |= 1 << Class; 209319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 209419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 209519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 209619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = GetObjCArg(Inst); 209719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 209819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // ARC calls with null are no-ops. Delete them. 209919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isNullOrUndef(Arg)) { 210019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 210119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumNoops; 210219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Inst); 210319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 210419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 210519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 210619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Keep track of which of retain, release, autorelease, and retain_block 210719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // are actually present in this function. 210819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UsedInThisFunction |= 1 << Class; 210919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 211019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If Arg is a PHI, and one or more incoming values to the 211119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // PHI are null, and the call is control-equivalent to the PHI, and there 211219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // are no relevant side effects between the PHI and the call, the call 211319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // could be pushed up to just those paths with non-null incoming values. 211419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For now, don't bother splitting critical edges for this. 211519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<std::pair<Instruction *, const Value *>, 4> Worklist; 211619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.push_back(std::make_pair(Inst, Arg)); 211719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 211819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::pair<Instruction *, const Value *> Pair = Worklist.pop_back_val(); 211919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Inst = Pair.first; 212019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = Pair.second; 212119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 212219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const PHINode *PN = dyn_cast<PHINode>(Arg); 212319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!PN) continue; 212419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 212519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Determine if the PHI has any null operands, or any incoming 212619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // critical edges. 212719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool HasNull = false; 212819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool HasCriticalEdges = false; 212919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 213019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Incoming = 213119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StripPointerCastsAndObjCCalls(PN->getIncomingValue(i)); 213219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isNullOrUndef(Incoming)) 213319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman HasNull = true; 213419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else if (cast<TerminatorInst>(PN->getIncomingBlock(i)->back()) 213519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman .getNumSuccessors() != 1) { 213619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman HasCriticalEdges = true; 213719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 213819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 213919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 214019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we have null operands and no critical edges, optimize. 214119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!HasCriticalEdges && HasNull) { 214219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 4> DependingInstructions; 214319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const BasicBlock *, 4> Visited; 214419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 214519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that there is nothing that cares about the reference 214619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // count between the call and the phi. 214719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FindDependencies(NeedsPositiveRetainCount, Arg, 214819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Inst->getParent(), Inst, 214919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions, Visited, PA); 215019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (DependingInstructions.size() == 1 && 215119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman *DependingInstructions.begin() == PN) { 215219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 215319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumPartialNoops; 215419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Clone the call into each predecessor that has a non-null value. 215519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *CInst = cast<CallInst>(Inst); 215619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *ParamTy = CInst->getArgOperand(0)->getType(); 215719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 215819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Incoming = 215919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StripPointerCastsAndObjCCalls(PN->getIncomingValue(i)); 216019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!isNullOrUndef(Incoming)) { 216119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Clone = cast<CallInst>(CInst->clone()); 216219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Op = PN->getIncomingValue(i); 216319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *InsertPos = &PN->getIncomingBlock(i)->back(); 216419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Op->getType() != ParamTy) 216519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Op = new BitCastInst(Op, ParamTy, "", InsertPos); 216619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Clone->setArgOperand(0, Op); 216719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Clone->insertBefore(InsertPos); 216819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Worklist.push_back(std::make_pair(Clone, Incoming)); 216919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 217019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 217119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Erase the original call. 217219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(CInst); 217319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 217419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 217519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 217619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (!Worklist.empty()); 217719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 217819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 217919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 218019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// CheckForCFGHazards - Check for critical edges, loop boundaries, irreducible 218119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// control flow, or other CFG structures where moving code across the edge 218219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// would result in it being executed more. 218319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid 218419bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB, 218519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 218619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBState &MyStates) const { 218719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If any top-down local-use or possible-dec has a succ which is earlier in 218819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // the sequence, forget it. 218919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (BBState::ptr_const_iterator I = MyStates.top_down_ptr_begin(), 219019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman E = MyStates.top_down_ptr_end(); I != E; ++I) 219119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (I->second.GetSeq()) { 219219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: break; 219319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: { 219419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = I->first; 219519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const TerminatorInst *TI = cast<TerminatorInst>(&BB->back()); 219619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool SomeSuccHasSame = false; 219719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool AllSuccsHaveSame = true; 219819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MyStates.getPtrTopDownState(Arg); 219919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (succ_const_iterator SI(TI), SE(TI, false); SI != SE; ++SI) { 220019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &SuccS = BBStates[*SI].getPtrBottomUpState(Arg); 220119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (SuccS.GetSeq()) { 220219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 220319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: { 220419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!S.RRI.KnownSafe && !SuccS.RRI.KnownSafe) 220519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.ClearSequenceProgress(); 220619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 220719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 220819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 220919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SomeSuccHasSame = true; 221019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 221119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 221219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 221319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 221419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!S.RRI.KnownSafe && !SuccS.RRI.KnownSafe) 221519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AllSuccsHaveSame = false; 221619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 221719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 221819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("bottom-up pointer in retain state!"); 221919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 222019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 222119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the state at the other end of any of the successor edges 222219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // matches the current state, require all edges to match. This 222319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // guards against loops in the middle of a sequence. 222419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (SomeSuccHasSame && !AllSuccsHaveSame) 222519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.ClearSequenceProgress(); 222619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 222719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: { 222819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = I->first; 222919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const TerminatorInst *TI = cast<TerminatorInst>(&BB->back()); 223019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool SomeSuccHasSame = false; 223119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool AllSuccsHaveSame = true; 223219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MyStates.getPtrTopDownState(Arg); 223319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (succ_const_iterator SI(TI), SE(TI, false); SI != SE; ++SI) { 223419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &SuccS = BBStates[*SI].getPtrBottomUpState(Arg); 223519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (SuccS.GetSeq()) { 223619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: { 223719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!S.RRI.KnownSafe && !SuccS.RRI.KnownSafe) 223819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.ClearSequenceProgress(); 223919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 224019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 224119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 224219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SomeSuccHasSame = true; 224319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 224419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 224519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 224619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 224719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 224819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!S.RRI.KnownSafe && !SuccS.RRI.KnownSafe) 224919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AllSuccsHaveSame = false; 225019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 225119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 225219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("bottom-up pointer in retain state!"); 225319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 225419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 225519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the state at the other end of any of the successor edges 225619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // matches the current state, require all edges to match. This 225719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // guards against loops in the middle of a sequence. 225819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (SomeSuccHasSame && !AllSuccsHaveSame) 225919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.ClearSequenceProgress(); 226019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 226119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 226219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 226319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 226419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 226519bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::VisitBottomUp(BasicBlock *BB, 226619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 226719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains) { 226819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool NestingDetected = false; 226919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBState &MyStates = BBStates[BB]; 227019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 227119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Merge the states from each successor to compute the initial state 227219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // for the current block. 227319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const TerminatorInst *TI = cast<TerminatorInst>(&BB->back()); 227419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman succ_const_iterator SI(TI), SE(TI, false); 227519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (SI == SE) 227619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.SetAsExit(); 227719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else 227819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 227919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const BasicBlock *Succ = *SI++; 228019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Succ == BB) 228119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 228219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Succ); 228319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we haven't seen this node yet, then we've found a CFG cycle. 228419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Be optimistic here; it's CheckForCFGHazards' job detect trouble. 228519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (I == BBStates.end()) 228619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 228719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.InitFromSucc(I->second); 228819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (SI != SE) { 228919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Succ = *SI++; 229019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Succ != BB) { 229119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman I = BBStates.find(Succ); 229219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (I != BBStates.end()) 229319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.MergeSucc(I->second); 229419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 229519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 229619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 229719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (SI != SE); 229819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 229919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Visit all the instructions, bottom-up. 230019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (BasicBlock::iterator I = BB->end(), E = BB->begin(); I != E; --I) { 230119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = llvm::prior(I); 230219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetInstructionClass(Inst); 230319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = 0; 230419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 230519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 230619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Release: { 230719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = GetObjCArg(Inst); 230819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 230919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MyStates.getPtrBottomUpState(Arg); 231019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 231119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we see two releases in a row on the same pointer. If so, make 231219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // a note, and we'll cicle back to revisit it after we've 231319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // hopefully eliminated the second release, which may allow us to 231419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // eliminate the first release too. 231519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Theoretically we could implement removal of nested retain+release 231619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pairs by making PtrState hold a stack of states, but this is 231719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // simple and avoids adding overhead for the non-nested case. 231819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (S.GetSeq() == S_Release || S.GetSeq() == S_MovableRelease) 231919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NestingDetected = true; 232019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 232119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeqToRelease(Inst->getMetadata(ImpreciseReleaseMDKind)); 232219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.clear(); 232319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.KnownSafe = S.IsKnownNested() || S.IsKnownIncremented(); 232419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall(); 232519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.Calls.insert(Inst); 232619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 232719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.IncrementRefCount(); 232819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.IncrementNestCount(); 232919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 233019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 233119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainBlock: 233219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 233319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: { 233419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = GetObjCArg(Inst); 233519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 233619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MyStates.getPtrBottomUpState(Arg); 233719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.DecrementRefCount(); 233819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetAtLeastOneRefCount(); 233919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.DecrementNestCount(); 234019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 234119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // An objc_retainBlock call with just a use still needs to be kept, 234219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // because it may be copying a block from the stack to the heap. 234319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_RetainBlock && S.GetSeq() == S_Use) 234419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_CanRelease); 234519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 234619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (S.GetSeq()) { 234719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 234819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 234919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 235019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 235119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReverseInsertPts.clear(); 235219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // FALL THROUGH 235319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 235419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Don't do retain+release tracking for IC_RetainRV, because it's 235519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // better to let it remain as the first instruction after a call. 235619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class != IC_RetainRV) { 235719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.IsRetainBlock = Class == IC_RetainBlock; 235819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retains[Inst] = S.RRI; 235919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 236019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.ClearSequenceProgress(); 236119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 236219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 236319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 236419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 236519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("bottom-up pointer in retain state!"); 236619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 236719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 236819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 236919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPop: 237019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Conservatively, clear MyStates for all known pointers. 237119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.clearBottomUpPointers(); 237219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 237319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPush: 237419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_None: 237519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These are irrelevant. 237619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 237719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 237819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 237919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 238019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 238119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Consider any other possible effects of this instruction on each 238219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pointer being tracked. 238319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (BBState::ptr_iterator MI = MyStates.bottom_up_ptr_begin(), 238419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ME = MyStates.bottom_up_ptr_end(); MI != ME; ++MI) { 238519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Ptr = MI->first; 238619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Ptr == Arg) 238719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; // Handled above. 238819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MI->second; 238919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Sequence Seq = S.GetSeq(); 239019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 239119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for possible releases. 239219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (CanAlterRefCount(Inst, Ptr, PA, Class)) { 239319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.DecrementRefCount(); 239419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Seq) { 239519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 239619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_CanRelease); 239719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 239819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 239919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 240019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 240119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 240219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 240319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 240419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 240519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("bottom-up pointer in retain state!"); 240619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 240719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 240819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 240919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for possible direct uses. 241019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Seq) { 241119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 241219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 241319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (CanUse(Inst, Ptr, PA, Class)) { 241419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(S.RRI.ReverseInsertPts.empty()); 241519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReverseInsertPts.insert(Inst); 241619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_Use); 241719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else if (Seq == S_Release && 241819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (Class == IC_User || Class == IC_CallOrUser)) { 241919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Non-movable releases depend on any possible objc pointer use. 242019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_Stop); 242119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(S.RRI.ReverseInsertPts.empty()); 242219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReverseInsertPts.insert(Inst); 242319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 242419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 242519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 242619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (CanUse(Inst, Ptr, PA, Class)) 242719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_Use); 242819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 242919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 243019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 243119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 243219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 243319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 243419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("bottom-up pointer in retain state!"); 243519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 243619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 243719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 243819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 243919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return NestingDetected; 244019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 244119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 244219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 244319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::VisitTopDown(BasicBlock *BB, 244419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 244519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases) { 244619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool NestingDetected = false; 244719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBState &MyStates = BBStates[BB]; 244819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 244919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Merge the states from each predecessor to compute the initial state 245019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // for the current block. 245119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const_pred_iterator PI(BB), PE(BB, false); 245219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PI == PE) 245319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.SetAsEntry(); 245419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else 245519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman do { 245619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const BasicBlock *Pred = *PI++; 245719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pred == BB) 245819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 245919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Pred); 246019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(I != BBStates.end()); 246119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we haven't seen this node yet, then we've found a CFG cycle. 246219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Be optimistic here; it's CheckForCFGHazards' job detect trouble. 246319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!I->second.isVisitedTopDown()) 246419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 246519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.InitFromPred(I->second); 246619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (PI != PE) { 246719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Pred = *PI++; 246819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Pred != BB) { 246919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman I = BBStates.find(Pred); 247019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(I != BBStates.end()); 247119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (I->second.isVisitedTopDown()) 247219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.MergePred(I->second); 247319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 247419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 247519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 247619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } while (PI != PE); 247719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 247819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Visit all the instructions, top-down. 247919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 248019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = I; 248119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetInstructionClass(Inst); 248219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = 0; 248319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 248419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 248519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainBlock: 248619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 248719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: { 248819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = GetObjCArg(Inst); 248919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 249019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MyStates.getPtrTopDownState(Arg); 249119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 249219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Don't do retain+release tracking for IC_RetainRV, because it's 249319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // better to let it remain as the first instruction after a call. 249419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class != IC_RetainRV) { 249519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we see two retains in a row on the same pointer. If so, make 249619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // a note, and we'll cicle back to revisit it after we've 249719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // hopefully eliminated the second retain, which may allow us to 249819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // eliminate the first retain too. 249919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Theoretically we could implement removal of nested retain+release 250019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pairs by making PtrState hold a stack of states, but this is 250119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // simple and avoids adding overhead for the non-nested case. 250219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (S.GetSeq() == S_Retain) 250319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NestingDetected = true; 250419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 250519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_Retain); 250619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.clear(); 250719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.IsRetainBlock = Class == IC_RetainBlock; 250819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Don't check S.IsKnownIncremented() here because it's not 250919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // sufficient. 251019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.KnownSafe = S.IsKnownNested(); 251119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.Calls.insert(Inst); 251219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 251319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 251419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetAtLeastOneRefCount(); 251519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.IncrementRefCount(); 251619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.IncrementNestCount(); 251719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 251819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 251919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Release: { 252019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = GetObjCArg(Inst); 252119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 252219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MyStates.getPtrTopDownState(Arg); 252319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.DecrementRefCount(); 252419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.DecrementNestCount(); 252519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 252619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (S.GetSeq()) { 252719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 252819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 252919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReverseInsertPts.clear(); 253019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // FALL THROUGH 253119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 253219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind); 253319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall(); 253419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Releases[Inst] = S.RRI; 253519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.ClearSequenceProgress(); 253619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 253719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 253819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 253919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 254019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 254119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 254219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("top-down pointer in release state!"); 254319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 254419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 254519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 254619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPop: 254719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Conservatively, clear MyStates for all known pointers. 254819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyStates.clearTopDownPointers(); 254919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 255019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPush: 255119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_None: 255219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These are irrelevant. 255319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 255419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 255519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 255619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 255719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 255819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Consider any other possible effects of this instruction on each 255919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pointer being tracked. 256019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (BBState::ptr_iterator MI = MyStates.top_down_ptr_begin(), 256119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ME = MyStates.top_down_ptr_end(); MI != ME; ++MI) { 256219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Ptr = MI->first; 256319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Ptr == Arg) 256419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; // Handled above. 256519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PtrState &S = MI->second; 256619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Sequence Seq = S.GetSeq(); 256719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 256819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for possible releases. 256919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (CanAlterRefCount(Inst, Ptr, PA, Class)) { 257019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.DecrementRefCount(); 257119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Seq) { 257219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 257319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_CanRelease); 257419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(S.RRI.ReverseInsertPts.empty()); 257519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReverseInsertPts.insert(Inst); 257619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 257719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // One call can't cause a transition from S_Retain to S_CanRelease 257819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // and S_CanRelease to S_Use. If we've made the first transition, 257919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // we're done. 258019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 258119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 258219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 258319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 258419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 258519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 258619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 258719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 258819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("top-down pointer in release state!"); 258919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 259019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 259119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 259219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check for possible direct uses. 259319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Seq) { 259419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_CanRelease: 259519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (CanUse(Inst, Ptr, PA, Class)) 259619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_Use); 259719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 259819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Retain: 259919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // An objc_retainBlock call may be responsible for copying the block 260019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // data from the stack to the heap. Model this by moving it straight 260119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // from S_Retain to S_Use. 260219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (S.RRI.IsRetainBlock && 260319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CanUse(Inst, Ptr, PA, Class)) { 260419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(S.RRI.ReverseInsertPts.empty()); 260519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.RRI.ReverseInsertPts.insert(Inst); 260619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman S.SetSeq(S_Use); 260719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 260819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 260919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Use: 261019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_None: 261119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 261219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Stop: 261319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_Release: 261419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case S_MovableRelease: 261519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman llvm_unreachable("top-down pointer in release state!"); 261619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 261719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 261819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 261919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 262019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CheckForCFGHazards(BB, BBStates, MyStates); 262119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return NestingDetected; 262219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 262319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 262419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// Visit - Visit the function both top-down and bottom-up. 262519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 262619bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::Visit(Function &F, 262719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> &BBStates, 262819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains, 262919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases) { 263019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Use reverse-postorder on the reverse CFG for bottom-up, because we 263119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // magically know that loops will be well behaved, i.e. they won't repeatedly 263219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // call retain on a single pointer without doing a release. We can't use 263319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // ReversePostOrderTraversal here because we want to walk up from each 263419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // function exit point. 263519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<BasicBlock *, 16> Visited; 263619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<std::pair<BasicBlock *, pred_iterator>, 16> Stack; 263719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<BasicBlock *, 16> Order; 263819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) { 263919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = I; 264019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (BB->getTerminator()->getNumSuccessors() == 0) 264119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Stack.push_back(std::make_pair(BB, pred_begin(BB))); 264219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 264319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (!Stack.empty()) { 264419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman pred_iterator End = pred_end(Stack.back().first); 264519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (Stack.back().second != End) { 264619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = *Stack.back().second++; 264719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Visited.insert(BB)) 264819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Stack.push_back(std::make_pair(BB, pred_begin(BB))); 264919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 265019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Order.push_back(Stack.pop_back_val().first); 265119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 265219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool BottomUpNestingDetected = false; 265319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallVectorImpl<BasicBlock *>::const_reverse_iterator I = 265419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Order.rbegin(), E = Order.rend(); I != E; ++I) { 265519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = *I; 265619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BottomUpNestingDetected |= VisitBottomUp(BB, BBStates, Retains); 265719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 265819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 265919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Use regular reverse-postorder for top-down. 266019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool TopDownNestingDetected = false; 266119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typedef ReversePostOrderTraversal<Function *> RPOTType; 266219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RPOTType RPOT(&F); 266319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (RPOTType::rpo_iterator I = RPOT.begin(), E = RPOT.end(); I != E; ++I) { 266419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = *I; 266519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman TopDownNestingDetected |= VisitTopDown(BB, BBStates, Releases); 266619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 266719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 266819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return TopDownNestingDetected && BottomUpNestingDetected; 266919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 267019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 267119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// MoveCalls - Move the calls in RetainsToMove and ReleasesToMove. 267219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCOpt::MoveCalls(Value *Arg, 267319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRInfo &RetainsToMove, 267419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRInfo &ReleasesToMove, 267519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains, 267619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases, 267719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVectorImpl<Instruction *> &DeadInsts, 267819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Module *M) { 267919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *ArgTy = Arg->getType(); 268019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *ParamTy = PointerType::getUnqual(Type::getInt8Ty(ArgTy->getContext())); 268119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 268219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Insert the new retain and release calls. 268319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 268419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PI = ReleasesToMove.ReverseInsertPts.begin(), 268519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PE = ReleasesToMove.ReverseInsertPts.end(); PI != PE; ++PI) { 268619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *InsertPt = *PI; 268719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *MyArg = ArgTy == ParamTy ? Arg : 268819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman new BitCastInst(Arg, ParamTy, "", InsertPt); 268919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = 269019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst::Create(RetainsToMove.IsRetainBlock ? 269119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman getRetainBlockCallee(M) : getRetainCallee(M), 269219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MyArg, "", InsertPt); 269319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->setDoesNotThrow(); 269419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainsToMove.IsRetainBlock) 269519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->setTailCall(); 269619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 269719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 269819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PI = RetainsToMove.ReverseInsertPts.begin(), 269919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PE = RetainsToMove.ReverseInsertPts.end(); PI != PE; ++PI) { 270019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *LastUse = *PI; 270119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *InsertPts[] = { 0, 0, 0 }; 270219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (InvokeInst *II = dyn_cast<InvokeInst>(LastUse)) { 270319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // We can't insert code immediately after an invoke instruction, so 270419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // insert code at the beginning of both successor blocks instead. 270519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // The invoke's return value isn't available in the unwind block, 270619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // but our releases will never depend on it, because they must be 270719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // paired with retains from before the invoke. 270819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InsertPts[0] = II->getNormalDest()->getFirstInsertionPt(); 270919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InsertPts[1] = II->getUnwindDest()->getFirstInsertionPt(); 271019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 271119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Insert code immediately after the last use. 271219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InsertPts[0] = llvm::next(BasicBlock::iterator(LastUse)); 271319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 271419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 271519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Instruction **I = InsertPts; *I; ++I) { 271619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *InsertPt = *I; 271719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *MyArg = ArgTy == ParamTy ? Arg : 271819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman new BitCastInst(Arg, ParamTy, "", InsertPt); 271919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = CallInst::Create(getReleaseCallee(M), MyArg, 272019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "", InsertPt); 272119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Attach a clang.imprecise_release metadata tag, if appropriate. 272219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (MDNode *M = ReleasesToMove.ReleaseMetadata) 272319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->setMetadata(ImpreciseReleaseMDKind, M); 272419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->setDoesNotThrow(); 272519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ReleasesToMove.IsTailCallRelease) 272619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->setTailCall(); 272719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 272819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 272919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 273019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Delete the original retain and release calls. 273119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 273219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AI = RetainsToMove.Calls.begin(), 273319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AE = RetainsToMove.Calls.end(); AI != AE; ++AI) { 273419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *OrigRetain = *AI; 273519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retains.blot(OrigRetain); 273619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DeadInsts.push_back(OrigRetain); 273719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 273819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 273919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AI = ReleasesToMove.Calls.begin(), 274019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AE = ReleasesToMove.Calls.end(); AI != AE; ++AI) { 274119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *OrigRelease = *AI; 274219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Releases.erase(OrigRelease); 274319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DeadInsts.push_back(OrigRelease); 274419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 274519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 274619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 274719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 274819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCOpt::PerformCodePlacement(DenseMap<const BasicBlock *, BBState> 274919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &BBStates, 275019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> &Retains, 275119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> &Releases, 275219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Module *M) { 275319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool AnyPairsCompletelyEliminated = false; 275419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRInfo RetainsToMove; 275519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RRInfo ReleasesToMove; 275619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<Instruction *, 4> NewRetains; 275719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<Instruction *, 4> NewReleases; 275819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallVector<Instruction *, 8> DeadInsts; 275919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 276019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (MapVector<Value *, RRInfo>::const_iterator I = Retains.begin(), 276119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman E = Retains.end(); I != E; ++I) { 276219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *V = I->first; 276319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!V) continue; // blotted 276419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 276519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Retain = cast<Instruction>(V); 276619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Arg = GetObjCArg(Retain); 276719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 276819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the object being released is in static storage, we know it's 276919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // not being managed by ObjC reference counting, so we can delete pairs 277019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // regardless of what possible decrements or uses lie between them. 277119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool KnownSafe = isa<Constant>(Arg); 277219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 277319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Same for stack storage, unless this is an objc_retainBlock call, 277419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // which is responsible for copying the block data from the stack to 277519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // the heap. 277619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!I->second.IsRetainBlock && isa<AllocaInst>(Arg)) 277719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman KnownSafe = true; 277819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 277919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // A constant pointer can't be pointing to an object on the heap. It may 278019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // be reference-counted, but it won't be deleted. 278119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const LoadInst *LI = dyn_cast<LoadInst>(Arg)) 278219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const GlobalVariable *GV = 278319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman dyn_cast<GlobalVariable>( 278419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StripPointerCastsAndObjCCalls(LI->getPointerOperand()))) 278519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GV->isConstant()) 278619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman KnownSafe = true; 278719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 278819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If a pair happens in a region where it is known that the reference count 278919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // is already incremented, we can similarly ignore possible decrements. 279019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool KnownSafeTD = true, KnownSafeBU = true; 279119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 279219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Connect the dots between the top-down-collected RetainsToMove and 279319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // bottom-up-collected ReleasesToMove to form sets of related calls. 279419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // This is an iterative process so that we connect multiple releases 279519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // to multiple retains if needed. 279619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned OldDelta = 0; 279719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned NewDelta = 0; 279819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned OldCount = 0; 279919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned NewCount = 0; 280019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool FirstRelease = true; 280119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool FirstRetain = true; 280219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetains.push_back(Retain); 280319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (;;) { 280419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallVectorImpl<Instruction *>::const_iterator 280519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NI = NewRetains.begin(), NE = NewRetains.end(); NI != NE; ++NI) { 280619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *NewRetain = *NI; 280719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo>::const_iterator It = Retains.find(NewRetain); 280819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(It != Retains.end()); 280919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const RRInfo &NewRetainRRI = It->second; 281019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman KnownSafeTD &= NewRetainRRI.KnownSafe; 281119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 281219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LI = NewRetainRRI.Calls.begin(), 281319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LE = NewRetainRRI.Calls.end(); LI != LE; ++LI) { 281419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *NewRetainRelease = *LI; 281519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo>::const_iterator Jt = 281619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Releases.find(NewRetainRelease); 281719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Jt == Releases.end()) 281819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_retain; 281919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const RRInfo &NewRetainReleaseRRI = Jt->second; 282019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(NewRetainReleaseRRI.Calls.count(NewRetain)); 282119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ReleasesToMove.Calls.insert(NewRetainRelease)) { 282219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OldDelta -= 282319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBStates[NewRetainRelease->getParent()].GetAllPathCount(); 282419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 282519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Merge the ReleaseMetadata and IsTailCallRelease values. 282619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (FirstRelease) { 282719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleasesToMove.ReleaseMetadata = 282819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetainReleaseRRI.ReleaseMetadata; 282919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleasesToMove.IsTailCallRelease = 283019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetainReleaseRRI.IsTailCallRelease; 283119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FirstRelease = false; 283219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 283319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ReleasesToMove.ReleaseMetadata != 283419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetainReleaseRRI.ReleaseMetadata) 283519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleasesToMove.ReleaseMetadata = 0; 283619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ReleasesToMove.IsTailCallRelease != 283719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetainReleaseRRI.IsTailCallRelease) 283819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleasesToMove.IsTailCallRelease = false; 283919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 284019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 284119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Collect the optimal insertion points. 284219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!KnownSafe) 284319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 284419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RI = NewRetainReleaseRRI.ReverseInsertPts.begin(), 284519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RE = NewRetainReleaseRRI.ReverseInsertPts.end(); 284619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RI != RE; ++RI) { 284719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *RIP = *RI; 284819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ReleasesToMove.ReverseInsertPts.insert(RIP)) 284919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewDelta -= BBStates[RIP->getParent()].GetAllPathCount(); 285019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 285119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewReleases.push_back(NewRetainRelease); 285219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 285319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 285419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 285519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetains.clear(); 285619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NewReleases.empty()) break; 285719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 285819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Back the other way. 285919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallVectorImpl<Instruction *>::const_iterator 286019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NI = NewReleases.begin(), NE = NewReleases.end(); NI != NE; ++NI) { 286119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *NewRelease = *NI; 286219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo>::const_iterator It = 286319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Releases.find(NewRelease); 286419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(It != Releases.end()); 286519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const RRInfo &NewReleaseRRI = It->second; 286619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman KnownSafeBU &= NewReleaseRRI.KnownSafe; 286719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 286819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LI = NewReleaseRRI.Calls.begin(), 286919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LE = NewReleaseRRI.Calls.end(); LI != LE; ++LI) { 287019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *NewReleaseRetain = *LI; 287119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo>::const_iterator Jt = 287219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retains.find(NewReleaseRetain); 287319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Jt == Retains.end()) 287419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_retain; 287519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const RRInfo &NewReleaseRetainRRI = Jt->second; 287619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman assert(NewReleaseRetainRRI.Calls.count(NewRelease)); 287719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RetainsToMove.Calls.insert(NewReleaseRetain)) { 287819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned PathCount = 287919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BBStates[NewReleaseRetain->getParent()].GetAllPathCount(); 288019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OldDelta += PathCount; 288119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OldCount += PathCount; 288219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 288319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Merge the IsRetainBlock values. 288419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (FirstRetain) { 288519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainsToMove.IsRetainBlock = NewReleaseRetainRRI.IsRetainBlock; 288619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FirstRetain = false; 288719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else if (ReleasesToMove.IsRetainBlock != 288819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewReleaseRetainRRI.IsRetainBlock) 288919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // It's not possible to merge the sequences if one uses 289019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_retain and the other uses objc_retainBlock. 289119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_retain; 289219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 289319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Collect the optimal insertion points. 289419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!KnownSafe) 289519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (SmallPtrSet<Instruction *, 2>::const_iterator 289619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RI = NewReleaseRetainRRI.ReverseInsertPts.begin(), 289719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RE = NewReleaseRetainRRI.ReverseInsertPts.end(); 289819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RI != RE; ++RI) { 289919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *RIP = *RI; 290019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (RetainsToMove.ReverseInsertPts.insert(RIP)) { 290119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PathCount = BBStates[RIP->getParent()].GetAllPathCount(); 290219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewDelta += PathCount; 290319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewCount += PathCount; 290419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 290519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 290619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetains.push_back(NewReleaseRetain); 290719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 290819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 290919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 291019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewReleases.clear(); 291119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NewRetains.empty()) break; 291219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 291319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 291419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the pointer is known incremented or nested, we can safely delete the 291519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // pair regardless of what's between them. 291619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (KnownSafeTD || KnownSafeBU) { 291719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainsToMove.ReverseInsertPts.clear(); 291819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleasesToMove.ReverseInsertPts.clear(); 291919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewCount = 0; 292019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 292119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Determine whether the new insertion points we computed preserve the 292219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // balance of retain and release calls through the program. 292319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // TODO: If the fully aggressive solution isn't valid, try to find a 292419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // less aggressive solution which is. 292519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NewDelta != 0) 292619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_retain; 292719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 292819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 292919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Determine whether the original call points are balanced in the retain and 293019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // release calls through the program. If not, conservatively don't touch 293119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // them. 293219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // TODO: It's theoretically possible to do code motion in this case, as 293319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // long as the existing imbalances are maintained. 293419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (OldDelta != 0) 293519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_retain; 293619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 293719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Ok, everything checks out and we're all set. Let's move some code! 293819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 293919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AnyPairsCompletelyEliminated = NewCount == 0; 294019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NumRRs += OldCount - NewCount; 294119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MoveCalls(Arg, RetainsToMove, ReleasesToMove, 294219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retains, Releases, DeadInsts, M); 294319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 294419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman next_retain: 294519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewReleases.clear(); 294619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NewRetains.clear(); 294719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainsToMove.clear(); 294819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleasesToMove.clear(); 294919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 295019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 295119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Now that we're done moving everything, we can delete the newly dead 295219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // instructions, as we no longer need them as insert points. 295319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (!DeadInsts.empty()) 295419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(DeadInsts.pop_back_val()); 295519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 295619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return AnyPairsCompletelyEliminated; 295719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 295819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 295919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeWeakCalls - Weak pointer optimizations. 296019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCOpt::OptimizeWeakCalls(Function &F) { 296119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // First, do memdep-style RLE and S2L optimizations. We can't use memdep 296219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // itself because it uses AliasAnalysis and we need to do provenance 296319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // queries instead. 296419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ) { 296519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = &*I++; 296619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetBasicInstructionClass(Inst); 296719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class != IC_LoadWeak && Class != IC_LoadWeakRetained) 296819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 296919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 297019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Delete objc_loadWeak calls with no users. 297119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_LoadWeak && Inst->use_empty()) { 297219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Inst->eraseFromParent(); 297319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 297419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 297519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 297619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // TODO: For now, just look for an earlier available version of this value 297719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // within the same block. Theoretically, we could do memdep-style non-local 297819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // analysis too, but that would want caching. A better approach would be to 297919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // use the technique that EarlyCSE uses. 298019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman inst_iterator Current = llvm::prior(I); 298119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *CurrentBB = Current.getBasicBlockIterator(); 298219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (BasicBlock::iterator B = CurrentBB->begin(), 298319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman J = Current.getInstructionIterator(); 298419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman J != B; --J) { 298519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *EarlierInst = &*llvm::prior(J); 298619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass EarlierClass = GetInstructionClass(EarlierInst); 298719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (EarlierClass) { 298819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_LoadWeak: 298919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_LoadWeakRetained: { 299019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If this is loading from the same pointer, replace this load's value 299119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // with that one. 299219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = cast<CallInst>(Inst); 299319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *EarlierCall = cast<CallInst>(EarlierInst); 299419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Arg = Call->getArgOperand(0); 299519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *EarlierArg = EarlierCall->getArgOperand(0); 299619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (PA.getAA()->alias(Arg, EarlierArg)) { 299719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::MustAlias: 299819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 299919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the load has a builtin retain, insert a plain retain for it. 300019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_LoadWeakRetained) { 300119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *CI = 300219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst::Create(getRetainCallee(F.getParent()), EarlierCall, 300319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "", Call); 300419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->setTailCall(); 300519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 300619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Zap the fully redundant load. 300719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->replaceAllUsesWith(EarlierCall); 300819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->eraseFromParent(); 300919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto clobbered; 301019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::MayAlias: 301119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::PartialAlias: 301219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto clobbered; 301319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::NoAlias: 301419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 301519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 301619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 301719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 301819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_StoreWeak: 301919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_InitWeak: { 302019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If this is storing to the same pointer and has the same size etc. 302119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // replace this load's value with the stored value. 302219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = cast<CallInst>(Inst); 302319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *EarlierCall = cast<CallInst>(EarlierInst); 302419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Arg = Call->getArgOperand(0); 302519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *EarlierArg = EarlierCall->getArgOperand(0); 302619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (PA.getAA()->alias(Arg, EarlierArg)) { 302719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::MustAlias: 302819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 302919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If the load has a builtin retain, insert a plain retain for it. 303019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_LoadWeakRetained) { 303119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *CI = 303219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst::Create(getRetainCallee(F.getParent()), EarlierCall, 303319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "", Call); 303419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->setTailCall(); 303519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 303619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Zap the fully redundant load. 303719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->replaceAllUsesWith(EarlierCall->getArgOperand(1)); 303819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Call->eraseFromParent(); 303919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto clobbered; 304019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::MayAlias: 304119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::PartialAlias: 304219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto clobbered; 304319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case AliasAnalysis::NoAlias: 304419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 304519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 304619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 304719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 304819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_MoveWeak: 304919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_CopyWeak: 305019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // TOOD: Grab the copied value. 305119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto clobbered; 305219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleasepoolPush: 305319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_None: 305419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_User: 305519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Weak pointers are only modified through the weak entry points 305619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // (and arbitrary calls, which could call the weak entry points). 305719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 305819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 305919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Anything else could modify the weak pointer. 306019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto clobbered; 306119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 306219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 306319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman clobbered:; 306419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 306519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 306619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Then, for each destroyWeak with an alloca operand, check to see if 306719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // the alloca and all its users can be zapped. 306819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ) { 306919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = &*I++; 307019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetBasicInstructionClass(Inst); 307119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class != IC_DestroyWeak) 307219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 307319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 307419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = cast<CallInst>(Inst); 307519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Arg = Call->getArgOperand(0); 307619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AllocaInst *Alloca = dyn_cast<AllocaInst>(Arg)) { 307719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Value::use_iterator UI = Alloca->use_begin(), 307819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UE = Alloca->use_end(); UI != UE; ++UI) { 307919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *UserInst = cast<Instruction>(*UI); 308019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (GetBasicInstructionClass(UserInst)) { 308119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_InitWeak: 308219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_StoreWeak: 308319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_DestroyWeak: 308419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 308519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 308619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto done; 308719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 308819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 308919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 309019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Value::use_iterator UI = Alloca->use_begin(), 309119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UE = Alloca->use_end(); UI != UE; ) { 309219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *UserInst = cast<CallInst>(*UI++); 309319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!UserInst->use_empty()) 309419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UserInst->replaceAllUsesWith(UserInst->getOperand(1)); 309519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UserInst->eraseFromParent(); 309619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 309719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Alloca->eraseFromParent(); 309819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman done:; 309919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 310019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 310119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 310219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 310319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeSequences - Identify program paths which execute sequences of 310419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// retains and releases which can be eliminated. 310519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCOpt::OptimizeSequences(Function &F) { 310619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Releases, Retains - These are used to store the results of the main flow 310719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// analysis. These use Value* as the key instead of Instruction* so that the 310819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// map stays valid when we get around to rewriting code and calls get 310919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// replaced by arguments. 311019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<Value *, RRInfo> Releases; 311119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman MapVector<Value *, RRInfo> Retains; 311219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 311319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// BBStates, This is used during the traversal of the function to track the 311419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// states for each identified object at each block. 311519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DenseMap<const BasicBlock *, BBState> BBStates; 311619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 311719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Analyze the CFG of the function, and all instructions. 311819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool NestingDetected = Visit(F, BBStates, Retains, Releases); 311919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 312019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Transform. 312119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return PerformCodePlacement(BBStates, Retains, Releases, F.getParent()) && 312219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman NestingDetected; 312319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 312419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 312519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// OptimizeReturns - Look for this pattern: 312619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// 312719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// %call = call i8* @something(...) 312819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// %2 = call i8* @objc_retain(i8* %call) 312919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// %3 = call i8* @objc_autorelease(i8* %2) 313019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// ret i8* %3 313119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// 313219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// And delete the retain and autorelease. 313319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// 313419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// Otherwise if it's just this: 313519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// 313619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// %3 = call i8* @objc_autorelease(i8* %2) 313719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// ret i8* %3 313819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// 313919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// convert the autorelease to autoreleaseRV. 314019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCOpt::OptimizeReturns(Function &F) { 314119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!F.getReturnType()->isPointerTy()) 314219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return; 314319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 314419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 4> DependingInstructions; 314519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const BasicBlock *, 4> Visited; 314619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) { 314719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = FI; 314819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReturnInst *Ret = dyn_cast<ReturnInst>(&BB->back()); 314919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Ret) continue; 315019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 315119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = StripPointerCastsAndObjCCalls(Ret->getOperand(0)); 315219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FindDependencies(NeedsPositiveRetainCount, Arg, 315319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BB, Ret, DependingInstructions, Visited, PA); 315419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (DependingInstructions.size() != 1) 315519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 315619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 315719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman { 315819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Autorelease = 315919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman dyn_cast_or_null<CallInst>(*DependingInstructions.begin()); 316019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Autorelease) 316119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 316219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass AutoreleaseClass = 316319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman GetBasicInstructionClass(Autorelease); 316419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!IsAutorelease(AutoreleaseClass)) 316519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 316619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GetObjCArg(Autorelease) != Arg) 316719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 316819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 316919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.clear(); 317019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Visited.clear(); 317119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 317219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that there is nothing that can affect the reference 317319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // count between the autorelease and the retain. 317419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FindDependencies(CanChangeRetainCount, Arg, 317519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BB, Autorelease, DependingInstructions, Visited, PA); 317619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (DependingInstructions.size() != 1) 317719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 317819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 317919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman { 318019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Retain = 318119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman dyn_cast_or_null<CallInst>(*DependingInstructions.begin()); 318219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 318319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that we found a retain with the same argument. 318419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Retain || 318519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman !IsRetain(GetBasicInstructionClass(Retain)) || 318619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman GetObjCArg(Retain) != Arg) 318719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 318819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 318919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.clear(); 319019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Visited.clear(); 319119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 319219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Convert the autorelease to an autoreleaseRV, since it's 319319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // returning the value. 319419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (AutoreleaseClass == IC_Autorelease) { 319519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Autorelease->setCalledFunction(getAutoreleaseRVCallee(F.getParent())); 319619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AutoreleaseClass = IC_AutoreleaseRV; 319719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 319819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 319919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that there is nothing that can affect the reference 320019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // count between the retain and the call. 320119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Note that Retain need not be in BB. 320219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FindDependencies(CanChangeRetainCount, Arg, Retain->getParent(), Retain, 320319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions, Visited, PA); 320419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (DependingInstructions.size() != 1) 320519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 320619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 320719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman { 320819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Call = 320919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman dyn_cast_or_null<CallInst>(*DependingInstructions.begin()); 321019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 321119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that the pointer is the return value of the call. 321219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Call || Arg != Call) 321319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 321419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 321519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that the call is a regular call. 321619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetBasicInstructionClass(Call); 321719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class != IC_CallOrUser && Class != IC_Call) 321819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman goto next_block; 321919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 322019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If so, we can zap the retain and autorelease. 322119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 322219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumRets; 322319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Retain); 322419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Autorelease); 322519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 322619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 322719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 322819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 322919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman next_block: 323019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.clear(); 323119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Visited.clear(); 323219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 323319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 323419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 323519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCOpt::doInitialization(Module &M) { 323619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 323719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 323819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 323919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Run = ModuleHasARC(M); 324019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Run) 324119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 324219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 324319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Identify the imprecise release metadata kind. 324419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ImpreciseReleaseMDKind = 324519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getContext().getMDKindID("clang.imprecise_release"); 324619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 324719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Intuitively, objc_retain and others are nocapture, however in practice 324819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // they are not, because they return their argument value. And objc_release 324919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // calls finalizers. 325019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 325119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These are initialized lazily. 325219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainRVCallee = 0; 325319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AutoreleaseRVCallee = 0; 325419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ReleaseCallee = 0; 325519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainCallee = 0; 325619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainBlockCallee = 0; 325719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AutoreleaseCallee = 0; 325819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 325919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 326019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 326119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 326219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCOpt::runOnFunction(Function &F) { 326319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 326419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 326519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 326619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If nothing in the Module uses ARC, don't do anything. 326719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Run) 326819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 326919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 327019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = false; 327119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 327219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PA.setAA(&getAnalysis<AliasAnalysis>()); 327319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 327419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // This pass performs several distinct transformations. As a compile-time aid 327519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // when compiling code that isn't ObjC, skip these if the relevant ObjC 327619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // library functions aren't declared. 327719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 327819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Preliminary optimizations. This also computs UsedInThisFunction. 327919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OptimizeIndividualCalls(F); 328019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 328119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Optimizations for weak pointers. 328219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UsedInThisFunction & ((1 << IC_LoadWeak) | 328319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_LoadWeakRetained) | 328419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_StoreWeak) | 328519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_InitWeak) | 328619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_CopyWeak) | 328719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_MoveWeak) | 328819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_DestroyWeak))) 328919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OptimizeWeakCalls(F); 329019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 329119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Optimizations for retain+release pairs. 329219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UsedInThisFunction & ((1 << IC_Retain) | 329319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_RetainRV) | 329419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (1 << IC_RetainBlock))) 329519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UsedInThisFunction & (1 << IC_Release)) 329619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Run OptimizeSequences until it either stops making changes or 329719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // no retain+release pair nesting is detected. 329819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (OptimizeSequences(F)) {} 329919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 330019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Optimizations if objc_autorelease is used. 330119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (UsedInThisFunction & 330219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ((1 << IC_Autorelease) | (1 << IC_AutoreleaseRV))) 330319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman OptimizeReturns(F); 330419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 330519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Changed; 330619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 330719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 330819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCOpt::releaseMemory() { 330919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PA.clear(); 331019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 331119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 331219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 331319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// ARC contraction. 331419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman//===----------------------------------------------------------------------===// 331519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 331619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// TODO: ObjCARCContract could insert PHI nodes when uses aren't 331719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// dominated by single calls. 331819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 331919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Operator.h" 332019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/InlineAsm.h" 332119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Analysis/Dominators.h" 332219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 332319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanSTATISTIC(NumStoreStrongs, "Number objc_storeStrong calls formed"); 332419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 332519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumannamespace { 332619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// ObjCARCContract - Late ARC optimizations. These change the IR in a way 332719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// that makes it difficult to be analyzed by ObjCARCOpt, so it's run late. 332819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman class ObjCARCContract : public FunctionPass { 332919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Changed; 333019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis *AA; 333119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DominatorTree *DT; 333219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ProvenanceAnalysis PA; 333319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 333419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// Run - A flag indicating whether this optimization pass should run. 333519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool Run; 333619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 333719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// StoreStrongCallee, etc. - Declarations for ObjC runtime 333819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// functions, for use in creating calls to them. These are initialized 333919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// lazily to avoid cluttering up the Module with unused declarations. 334019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *StoreStrongCallee, 334119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman *RetainAutoreleaseCallee, *RetainAutoreleaseRVCallee; 334219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 334319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// RetainRVMarker - The inline asm string to insert between calls and 334419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// RetainRV calls to make the optimization work on targets which need it. 334519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const MDString *RetainRVMarker; 334619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 334719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getStoreStrongCallee(Module *M); 334819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getRetainAutoreleaseCallee(Module *M); 334919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Constant *getRetainAutoreleaseRVCallee(Module *M); 335019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 335119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman bool ContractAutorelease(Function &F, Instruction *Autorelease, 335219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class, 335319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 4> 335419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &DependingInstructions, 335519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const BasicBlock *, 4> 335619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &Visited); 335719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 335819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman void ContractRelease(Instruction *Release, 335919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman inst_iterator &Iter); 336019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 336119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual void getAnalysisUsage(AnalysisUsage &AU) const; 336219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool doInitialization(Module &M); 336319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman virtual bool runOnFunction(Function &F); 336419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 336519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman public: 336619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static char ID; 336719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ObjCARCContract() : FunctionPass(ID) { 336819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman initializeObjCARCContractPass(*PassRegistry::getPassRegistry()); 336919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 337019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman }; 337119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 337219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 337319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanchar ObjCARCContract::ID = 0; 337419bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS_BEGIN(ObjCARCContract, 337519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc-arc-contract", "ObjC ARC contraction", false, false) 337619bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_AG_DEPENDENCY(AliasAnalysis) 337719bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS_DEPENDENCY(DominatorTree) 337819bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanINITIALIZE_PASS_END(ObjCARCContract, 337919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc-arc-contract", "ObjC ARC contraction", false, false) 338019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 338119bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanPass *llvm::createObjCARCContractPass() { 338219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return new ObjCARCContract(); 338319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 338419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 338519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCContract::getAnalysisUsage(AnalysisUsage &AU) const { 338619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.addRequired<AliasAnalysis>(); 338719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.addRequired<DominatorTree>(); 338819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AU.setPreservesCFG(); 338919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 339019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 339119bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCContract::getStoreStrongCallee(Module *M) { 339219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!StoreStrongCallee) { 339319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 339419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); 339519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8XX = PointerType::getUnqual(I8X); 339619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 339719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(I8XX); 339819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(I8X); 339919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 340019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 340119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 340219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(1, Attribute::NoCapture); 340319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 340419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StoreStrongCallee = 340519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction( 340619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman "objc_storeStrong", 340719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(Type::getVoidTy(C), Params, /*isVarArg=*/false), 340819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 340919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 341019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return StoreStrongCallee; 341119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 341219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 341319bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCContract::getRetainAutoreleaseCallee(Module *M) { 341419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainAutoreleaseCallee) { 341519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 341619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); 341719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 341819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(I8X); 341919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType *FTy = 342019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(I8X, Params, /*isVarArg=*/false); 342119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 342219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 342319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainAutoreleaseCallee = 342419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction("objc_retainAutorelease", FTy, Attributes); 342519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 342619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return RetainAutoreleaseCallee; 342719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 342819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 342919bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanConstant *ObjCARCContract::getRetainAutoreleaseRVCallee(Module *M) { 343019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainAutoreleaseRVCallee) { 343119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = M->getContext(); 343219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); 343319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman std::vector<Type *> Params; 343419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Params.push_back(I8X); 343519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType *FTy = 343619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FunctionType::get(I8X, Params, /*isVarArg=*/false); 343719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AttrListPtr Attributes; 343819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes.addAttr(~0u, Attribute::NoUnwind); 343919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainAutoreleaseRVCallee = 344019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M->getOrInsertFunction("objc_retainAutoreleaseReturnValue", FTy, 344119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Attributes); 344219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 344319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return RetainAutoreleaseRVCallee; 344419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 344519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 344619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// ContractAutorelease - Merge an autorelease with a retain into a fused 344719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// call. 344819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool 344919bac1e08be200c31efd26f0f5fd144c9b3eefd3John BaumanObjCARCContract::ContractAutorelease(Function &F, Instruction *Autorelease, 345019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class, 345119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 4> 345219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &DependingInstructions, 345319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const BasicBlock *, 4> 345419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &Visited) { 345519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = GetObjCArg(Autorelease); 345619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 345719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Check that there are no instructions between the retain and the autorelease 345819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // (such as an autorelease_pop) which may change the count. 345919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *Retain = 0; 346019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_AutoreleaseRV) 346119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FindDependencies(RetainAutoreleaseRVDep, Arg, 346219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Autorelease->getParent(), Autorelease, 346319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions, Visited, PA); 346419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else 346519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman FindDependencies(RetainAutoreleaseDep, Arg, 346619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Autorelease->getParent(), Autorelease, 346719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions, Visited, PA); 346819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 346919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Visited.clear(); 347019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (DependingInstructions.size() != 1) { 347119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.clear(); 347219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 347319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 347419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 347519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retain = dyn_cast_or_null<CallInst>(*DependingInstructions.begin()); 347619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DependingInstructions.clear(); 347719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 347819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Retain || 347919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman GetBasicInstructionClass(Retain) != IC_Retain || 348019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman GetObjCArg(Retain) != Arg) 348119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 348219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 348319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 348419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumPeeps; 348519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 348619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Class == IC_AutoreleaseRV) 348719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retain->setCalledFunction(getRetainAutoreleaseRVCallee(F.getParent())); 348819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else 348919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Retain->setCalledFunction(getRetainAutoreleaseCallee(F.getParent())); 349019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 349119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Autorelease); 349219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return true; 349319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 349419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 349519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// ContractRelease - Attempt to merge an objc_release with a store, load, and 349619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// objc_retain to form an objc_storeStrong. This can be a little tricky because 349719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// the instructions don't always appear in order, and there may be unrelated 349819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman/// intervening instructions. 349919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanvoid ObjCARCContract::ContractRelease(Instruction *Release, 350019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman inst_iterator &Iter) { 350119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LoadInst *Load = dyn_cast<LoadInst>(GetObjCArg(Release)); 350219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Load || !Load->isSimple()) return; 350319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 350419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For now, require everything to be in one basic block. 350519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = Release->getParent(); 350619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Load->getParent() != BB) return; 350719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 350819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Walk down to find the store. 350919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator I = Load, End = BB->end(); 351019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++I; 351119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AliasAnalysis::Location Loc = AA->getLocation(Load); 351219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (I != End && 351319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (&*I == Release || 351419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IsRetain(GetBasicInstructionClass(I)) || 351519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman !(AA->getModRefInfo(I, Loc) & AliasAnalysis::Mod))) 351619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++I; 351719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StoreInst *Store = dyn_cast<StoreInst>(I); 351819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Store || !Store->isSimple()) return; 351919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Store->getPointerOperand() != Loc.Ptr) return; 352019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 352119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *New = StripPointerCastsAndObjCCalls(Store->getValueOperand()); 352219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 352319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Walk up to find the retain. 352419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman I = Store; 352519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator Begin = BB->begin(); 352619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (I != Begin && GetBasicInstructionClass(I) != IC_Retain) 352719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman --I; 352819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Retain = I; 352919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GetBasicInstructionClass(Retain) != IC_Retain) return; 353019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (GetObjCArg(Retain) != New) return; 353119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 353219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 353319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++NumStoreStrongs; 353419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 353519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LLVMContext &C = Release->getContext(); 353619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); 353719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *I8XX = PointerType::getUnqual(I8X); 353819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 353919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Args[] = { Load->getPointerOperand(), New }; 354019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Args[0]->getType() != I8XX) 354119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Args[0] = new BitCastInst(Args[0], I8XX, "", Store); 354219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Args[1]->getType() != I8X) 354319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Args[1] = new BitCastInst(Args[1], I8X, "", Store); 354419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *StoreStrong = 354519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst::Create(getStoreStrongCallee(BB->getParent()->getParent()), 354619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Args, "", Store); 354719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StoreStrong->setDoesNotThrow(); 354819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StoreStrong->setDebugLoc(Store->getDebugLoc()); 354919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 355019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (&*Iter == Store) ++Iter; 355119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Store->eraseFromParent(); 355219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Release->eraseFromParent(); 355319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman EraseInstruction(Retain); 355419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Load->use_empty()) 355519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Load->eraseFromParent(); 355619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 355719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 355819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCContract::doInitialization(Module &M) { 355919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Run = ModuleHasARC(M); 356019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Run) 356119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 356219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 356319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // These are initialized lazily. 356419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman StoreStrongCallee = 0; 356519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainAutoreleaseCallee = 0; 356619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainAutoreleaseRVCallee = 0; 356719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 356819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Initialize RetainRVMarker. 356919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainRVMarker = 0; 357019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NamedMDNode *NMD = 357119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman M.getNamedMetadata("clang.arc.retainAutoreleasedReturnValueMarker")) 357219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (NMD->getNumOperands() == 1) { 357319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const MDNode *N = NMD->getOperand(0); 357419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (N->getNumOperands() == 1) 357519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const MDString *S = dyn_cast<MDString>(N->getOperand(0))) 357619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainRVMarker = S; 357719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 357819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 357919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 358019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 358119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 358219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanbool ObjCARCContract::runOnFunction(Function &F) { 358319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!EnableARCOpts) 358419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 358519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 358619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If nothing in the Module uses ARC, don't do anything. 358719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!Run) 358819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return false; 358919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 359019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = false; 359119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman AA = &getAnalysis<AliasAnalysis>(); 359219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman DT = &getAnalysis<DominatorTree>(); 359319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 359419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PA.setAA(&getAnalysis<AliasAnalysis>()); 359519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 359619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For ObjC library calls which return their argument, replace uses of the 359719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // argument with uses of the call return value, if it dominates the use. This 359819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // reduces register pressure. 359919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<Instruction *, 4> DependingInstructions; 360019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman SmallPtrSet<const BasicBlock *, 4> Visited; 360119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ) { 360219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Inst = &*I++; 360319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 360419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Only these library routines return their argument. In particular, 360519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_retainBlock does not necessarily return its argument. 360619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InstructionClass Class = GetBasicInstructionClass(Inst); 360719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman switch (Class) { 360819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Retain: 360919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutorelease: 361019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_FusedRetainAutoreleaseRV: 361119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 361219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Autorelease: 361319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_AutoreleaseRV: 361419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (ContractAutorelease(F, Inst, Class, DependingInstructions, Visited)) 361519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 361619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 361719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_RetainRV: { 361819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we're compiling for a target which needs a special inline-asm 361919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // marker to do the retainAutoreleasedReturnValue optimization, 362019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // insert it now. 362119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!RetainRVMarker) 362219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 362319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock::iterator BBI = Inst; 362419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman --BBI; 362519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman while (isNoopInstruction(BBI)) --BBI; 362619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (&*BBI == GetObjCArg(Inst)) { 362719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InlineAsm *IA = 362819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman InlineAsm::get(FunctionType::get(Type::getVoidTy(Inst->getContext()), 362919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /*isVarArg=*/false), 363019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman RetainRVMarker->getString(), 363119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /*Constraints=*/"", /*hasSideEffects=*/true); 363219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst::Create(IA, "", Inst); 363319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 363419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 363519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 363619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_InitWeak: { 363719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // objc_initWeak(p, null) => *p = null 363819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CallInst *CI = cast<CallInst>(Inst); 363919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (isNullOrUndef(CI->getArgOperand(1))) { 364019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Value *Null = 364119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ConstantPointerNull::get(cast<PointerType>(CI->getType())); 364219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 364319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman new StoreInst(Null, CI->getArgOperand(0), CI); 364419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->replaceAllUsesWith(Null); 364519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman CI->eraseFromParent(); 364619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 364719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 364819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 364919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman case IC_Release: 365019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ContractRelease(Inst, I); 365119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 365219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman default: 365319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman continue; 365419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 365519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 365619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Don't use GetObjCArg because we don't want to look through bitcasts 365719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // and such; to do the replacement, the argument must have type i8*. 365819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman const Value *Arg = cast<CallInst>(Inst)->getArgOperand(0); 365919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (;;) { 366019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If we're compiling bugpointed code, don't get in trouble. 366119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (!isa<Instruction>(Arg) && !isa<Argument>(Arg)) 366219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 366319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Look through the uses of the pointer. 366419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end(); 366519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman UI != UE; ) { 366619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Use &U = UI.getUse(); 366719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned OperandNo = UI.getOperandNo(); 366819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++UI; // Increment UI now, because we may unlink its element. 366919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Instruction *UserInst = dyn_cast<Instruction>(U.getUser())) 367019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Inst != UserInst && DT->dominates(Inst, UserInst)) { 367119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Changed = true; 367219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Instruction *Replacement = Inst; 367319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Type *UseTy = U.get()->getType(); 367419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PHINode *PHI = dyn_cast<PHINode>(UserInst)) { 367519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // For PHI nodes, insert the bitcast in the predecessor block. 367619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman unsigned ValNo = 367719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PHINode::getIncomingValueNumForOperand(OperandNo); 367819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman BasicBlock *BB = 367919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PHI->getIncomingBlock(ValNo); 368019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Replacement->getType() != UseTy) 368119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Replacement = new BitCastInst(Replacement, UseTy, "", 368219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &BB->back()); 368319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman for (unsigned i = 0, e = PHI->getNumIncomingValues(); 368419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman i != e; ++i) 368519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (PHI->getIncomingBlock(i) == BB) { 368619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // Keep the UI iterator valid. 368719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (&PHI->getOperandUse( 368819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PHINode::getOperandNumForIncomingValue(i)) == 368919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman &UI.getUse()) 369019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman ++UI; 369119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman PHI->setIncomingValue(i, Replacement); 369219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 369319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } else { 369419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (Replacement->getType() != UseTy) 369519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Replacement = new BitCastInst(Replacement, UseTy, "", UserInst); 369619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman U.set(Replacement); 369719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 369819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 369919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 370019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 370119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // If Arg is a no-op casted pointer, strip one level of casts and 370219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // iterate. 370319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman if (const BitCastInst *BI = dyn_cast<BitCastInst>(Arg)) 370419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = BI->getOperand(0); 370519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else if (isa<GEPOperator>(Arg) && 370619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman cast<GEPOperator>(Arg)->hasAllZeroIndices()) 370719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = cast<GEPOperator>(Arg)->getPointerOperand(); 370819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else if (isa<GlobalAlias>(Arg) && 370919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman !cast<GlobalAlias>(Arg)->mayBeOverridden()) 371019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman Arg = cast<GlobalAlias>(Arg)->getAliasee(); 371119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman else 371219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman break; 371319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 371419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 371519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 371619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return Changed; 371719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman} 3718