13b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner//===- GlobalsModRef.cpp - Simple Mod/Ref Analysis for Globals ------------===// 22b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman// 33b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// The LLVM Compiler Infrastructure 43b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 72b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman// 83b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner//===----------------------------------------------------------------------===// 93b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// 103b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// This simple pass provides alias and mod/ref information for global values 11fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner// that do not have their address taken, and keeps track of whether functions 12fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner// read or write memory (are "pure"). For this simple (but very common) case, 13fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner// we can provide pretty accurate and useful information. 143b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// 153b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner//===----------------------------------------------------------------------===// 163b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 173b27d68c6af2582df0962557f1fe5c3f70f46e3fChris Lattner#define DEBUG_TYPE "globalsmodref-aa" 183b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner#include "llvm/Analysis/Passes.h" 19d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/SCCIterator.h" 20d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/Statistic.h" 213b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner#include "llvm/Analysis/AliasAnalysis.h" 223b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner#include "llvm/Analysis/CallGraph.h" 23f006b183e2d2bebcf6968d1dd7350397c95b0325Victor Hernandez#include "llvm/Analysis/MemoryBuiltins.h" 245034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman#include "llvm/Analysis/ValueTracking.h" 250b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/Constants.h" 260b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/DerivedTypes.h" 270b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/Instructions.h" 280b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/IntrinsicInst.h" 290b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/Module.h" 30d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/Pass.h" 31551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/CommandLine.h" 32d7d83db5f22d05e5b14b6b1d838668222113c83aReid Spencer#include "llvm/Support/InstIterator.h" 333b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner#include <set> 343b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattnerusing namespace llvm; 353b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 363b27d68c6af2582df0962557f1fe5c3f70f46e3fChris LattnerSTATISTIC(NumNonAddrTakenGlobalVars, 373b27d68c6af2582df0962557f1fe5c3f70f46e3fChris Lattner "Number of global vars without address taken"); 383b27d68c6af2582df0962557f1fe5c3f70f46e3fChris LattnerSTATISTIC(NumNonAddrTakenFunctions,"Number of functions without address taken"); 393b27d68c6af2582df0962557f1fe5c3f70f46e3fChris LattnerSTATISTIC(NumNoMemFunctions, "Number of functions that do not access memory"); 403b27d68c6af2582df0962557f1fe5c3f70f46e3fChris LattnerSTATISTIC(NumReadMemFunctions, "Number of functions that only read memory"); 413b27d68c6af2582df0962557f1fe5c3f70f46e3fChris LattnerSTATISTIC(NumIndirectGlobalVars, "Number of indirect global objects"); 423b27d68c6af2582df0962557f1fe5c3f70f46e3fChris Lattner 433b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattnernamespace { 44fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// FunctionRecord - One instance of this structure is stored for every 45fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// function in the program. Later, the entries for these functions are 46fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// removed if the function is found to call an external function (in which 47fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// case we know nothing about it. 486726b6d75a8b679068a58cb954ba97cf9d1690baNick Lewycky struct FunctionRecord { 49fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// GlobalInfo - Maintain mod/ref info for all of the globals without 50fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// addresses taken that are read or written (transitively) by this 51fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// function. 5279fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::map<const GlobalValue*, unsigned> GlobalInfo; 53fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 542bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands /// MayReadAnyGlobal - May read global variables, but it is not known which. 552bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands bool MayReadAnyGlobal; 562bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands 5779fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman unsigned getInfoForGlobal(const GlobalValue *GV) const { 582bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands unsigned Effect = MayReadAnyGlobal ? AliasAnalysis::Ref : 0; 5979fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::map<const GlobalValue*, unsigned>::const_iterator I = 6079fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman GlobalInfo.find(GV); 61fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner if (I != GlobalInfo.end()) 622bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands Effect |= I->second; 632bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands return Effect; 64fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner } 652b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman 66fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// FunctionEffect - Capture whether or not this function reads or writes to 67fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// ANY memory. If not, we can do a lot of aggressive analysis on it. 68fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner unsigned FunctionEffect; 69105d26acb4158daea4e54919cfd12545a3d901eaChris Lattner 702bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands FunctionRecord() : MayReadAnyGlobal (false), FunctionEffect(0) {} 71fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner }; 723b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 73fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// GlobalsModRef - The actual analysis pass. 746726b6d75a8b679068a58cb954ba97cf9d1690baNick Lewycky class GlobalsModRef : public ModulePass, public AliasAnalysis { 75fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// NonAddressTakenGlobals - The globals that do not have their addresses 76fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// taken. 7779fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::set<const GlobalValue*> NonAddressTakenGlobals; 783b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 79ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner /// IndirectGlobals - The memory pointed to by this global is known to be 80ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner /// 'owned' by the global. 8179fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::set<const GlobalValue*> IndirectGlobals; 829a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 83ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner /// AllocsForIndirectGlobals - If an instruction allocates memory for an 84ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner /// indirect global, this map indicates which one. 8579fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::map<const Value*, const GlobalValue*> AllocsForIndirectGlobals; 869a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 873b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner /// FunctionInfo - For each function, keep track of what globals are 883b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner /// modified or read. 8979fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::map<const Function*, FunctionRecord> FunctionInfo; 903b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 913b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner public: 921997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel static char ID; 93081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson GlobalsModRef() : ModulePass(ID) { 94081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson initializeGlobalsModRefPass(*PassRegistry::getPassRegistry()); 95081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson } 961cee94f04111cfd7114979d6dfddce2669c9380dDevang Patel 97b12914bfc0f76a7a48357162d5f4c39a1343e69bChris Lattner bool runOnModule(Module &M) { 983b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner InitializeAliasAnalysis(this); // set up super class 993b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner AnalyzeGlobals(M); // find non-addr taken globals 1003b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner AnalyzeCallGraph(getAnalysis<CallGraph>(), M); // Propagate on CG 1013b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return false; 1023b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 1033b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 1043b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 1053b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner AliasAnalysis::getAnalysisUsage(AU); 1063b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner AU.addRequired<CallGraph>(); 1073b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner AU.setPreservesAll(); // Does not transform code 1083b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 1093b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 1103b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner //------------------------------------------------ 1113b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // Implement the AliasAnalysis API 1122b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman // 113b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman AliasResult alias(const Location &LocA, const Location &LocB); 11479fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman ModRefResult getModRefInfo(ImmutableCallSite CS, 115b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman const Location &Loc); 11679fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman ModRefResult getModRefInfo(ImmutableCallSite CS1, 11779fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman ImmutableCallSite CS2) { 11879fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman return AliasAnalysis::getModRefInfo(CS1, CS2); 1194a7ebfa4111305ea22fc753d4f029eed88149662Reid Spencer } 1203b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 1210af024c5d00c2a2d0e35ba33f4aaf4ed3fadfae2Chris Lattner /// getModRefBehavior - Return the behavior of the specified function if 1220af024c5d00c2a2d0e35ba33f4aaf4ed3fadfae2Chris Lattner /// called from the specified call site. The call site may be null in which 1230af024c5d00c2a2d0e35ba33f4aaf4ed3fadfae2Chris Lattner /// case the most generic behavior of this function should be returned. 124a41af344c2964573318a77e2b43eafd4d3804003Dan Gohman ModRefBehavior getModRefBehavior(const Function *F) { 12542c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman ModRefBehavior Min = UnknownModRefBehavior; 12642c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman 127ae9f3a3b7c915f725aef5a7250e88eaeddda03c6Anton Korobeynikov if (FunctionRecord *FR = getFunctionInfo(F)) { 128fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner if (FR->FunctionEffect == 0) 12942c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman Min = DoesNotAccessMemory; 130dedf2bd5a34dac25e4245f58bb902ced6b64edd9Misha Brukman else if ((FR->FunctionEffect & Mod) == 0) 13142c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman Min = OnlyReadsMemory; 132ae9f3a3b7c915f725aef5a7250e88eaeddda03c6Anton Korobeynikov } 13342c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman 13442c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman return ModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min); 135e79422096ea5319a365d160693d0957a2a4df75eOwen Anderson } 136e79422096ea5319a365d160693d0957a2a4df75eOwen Anderson 137e79422096ea5319a365d160693d0957a2a4df75eOwen Anderson /// getModRefBehavior - Return the behavior of the specified function if 138e79422096ea5319a365d160693d0957a2a4df75eOwen Anderson /// called from the specified call site. The call site may be null in which 139e79422096ea5319a365d160693d0957a2a4df75eOwen Anderson /// case the most generic behavior of this function should be returned. 140a41af344c2964573318a77e2b43eafd4d3804003Dan Gohman ModRefBehavior getModRefBehavior(ImmutableCallSite CS) { 14142c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman ModRefBehavior Min = UnknownModRefBehavior; 14242c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman 14342c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman if (const Function* F = CS.getCalledFunction()) 14442c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman if (FunctionRecord *FR = getFunctionInfo(F)) { 14542c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman if (FR->FunctionEffect == 0) 14642c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman Min = DoesNotAccessMemory; 14742c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman else if ((FR->FunctionEffect & Mod) == 0) 14842c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman Min = OnlyReadsMemory; 14942c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman } 15042c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman 15142c31a70735e55bf82e66a9315c97d1821c9a798Dan Gohman return ModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min); 152fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner } 153fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 1543b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner virtual void deleteValue(Value *V); 1553b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner virtual void copyValue(Value *From, Value *To); 156392249fcf368a22f48091a16c180160221c7e89aOwen Anderson virtual void addEscapingUse(Use &U); 1573b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 158fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner /// getAdjustedAnalysisPointer - This method is used when a pass implements 159fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner /// an analysis interface through multiple inheritance. If needed, it 160fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner /// should override this to adjust the this pointer as needed for the 161fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner /// specified pass info. 16290c579de5a383cee278acc3f7e7b9d0a656e6a35Owen Anderson virtual void *getAdjustedAnalysisPointer(AnalysisID PI) { 16390c579de5a383cee278acc3f7e7b9d0a656e6a35Owen Anderson if (PI == &AliasAnalysis::ID) 164fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner return (AliasAnalysis*)this; 165fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner return this; 166fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner } 167fc570e4bff4e08aaf8efa9f90a2cdb5b885f321cChris Lattner 1683b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner private: 169fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner /// getFunctionInfo - Return the function info for the function, or null if 1709a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands /// we don't have anything useful to say about it. 17179fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman FunctionRecord *getFunctionInfo(const Function *F) { 17279fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman std::map<const Function*, FunctionRecord>::iterator I = 17379fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman FunctionInfo.find(F); 174fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner if (I != FunctionInfo.end()) 175fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner return &I->second; 176fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner return 0; 177fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner } 178fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 1793b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner void AnalyzeGlobals(Module &M); 1803b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner void AnalyzeCallGraph(CallGraph &CG, Module &M); 181ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner bool AnalyzeUsesOfPointer(Value *V, std::vector<Function*> &Readers, 182ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner std::vector<Function*> &Writers, 183ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GlobalValue *OkayStoreDest = 0); 184ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner bool AnalyzeIndirectGlobalMemory(GlobalValue *GV); 1853b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner }; 1863b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 1873b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 188844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar GlobalsModRef::ID = 0; 1892ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_AG_PASS_BEGIN(GlobalsModRef, AliasAnalysis, 1902ab36d350293c77fc8941ce1023e4899df7e3a82Owen Anderson "globalsmodref-aa", "Simple mod/ref analysis for globals", 1912ab36d350293c77fc8941ce1023e4899df7e3a82Owen Anderson false, true, false) 1922ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_AG_DEPENDENCY(CallGraph) 1932ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_AG_PASS_END(GlobalsModRef, AliasAnalysis, 19402dd53e1c5b941ca5f60fca1b95ebcaf9ccd1dfcOwen Anderson "globalsmodref-aa", "Simple mod/ref analysis for globals", 195ce665bd2e2b581ab0858d1afe359192bac96b868Owen Anderson false, true, false) 196844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 1973b04a8ac455568f9b98ab7e9a43076260cb737aeChris LattnerPass *llvm::createGlobalsModRefPass() { return new GlobalsModRef(); } 1983b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 199ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// AnalyzeGlobals - Scan through the users of all of the internal 2009a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands/// GlobalValue's in the program. If none of them have their "address taken" 2013b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// (really, their address passed to something nontrivial), record this fact, 2023b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// and record the functions that they are used directly in. 2033b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattnervoid GlobalsModRef::AnalyzeGlobals(Module &M) { 2043b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner std::vector<Function*> Readers, Writers; 2053b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 206bb46f52027416598a662dc1c58f48d9d56b1a65bRafael Espindola if (I->hasLocalLinkage()) { 207ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (!AnalyzeUsesOfPointer(I, Readers, Writers)) { 208fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner // Remember that we are tracking this global. 209fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner NonAddressTakenGlobals.insert(I); 2103b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner ++NumNonAddrTakenFunctions; 2113b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 2123b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner Readers.clear(); Writers.clear(); 2133b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 2143b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 215f5eaf3c62c7b2f2da1f85ac411c4f13bcbf131f1Chris Lattner for (Module::global_iterator I = M.global_begin(), E = M.global_end(); 216f5eaf3c62c7b2f2da1f85ac411c4f13bcbf131f1Chris Lattner I != E; ++I) 217bb46f52027416598a662dc1c58f48d9d56b1a65bRafael Espindola if (I->hasLocalLinkage()) { 218ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (!AnalyzeUsesOfPointer(I, Readers, Writers)) { 2193b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // Remember that we are tracking this global, and the mod/ref fns 220fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner NonAddressTakenGlobals.insert(I); 2219a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 222fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner for (unsigned i = 0, e = Readers.size(); i != e; ++i) 223fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner FunctionInfo[Readers[i]].GlobalInfo[I] |= Ref; 224fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 225fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner if (!I->isConstant()) // No need to keep track of writers to constants 226fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner for (unsigned i = 0, e = Writers.size(); i != e; ++i) 227fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner FunctionInfo[Writers[i]].GlobalInfo[I] |= Mod; 2283b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner ++NumNonAddrTakenGlobalVars; 2299a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 230ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // If this global holds a pointer type, see if it is an indirect global. 2311df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands if (I->getType()->getElementType()->isPointerTy() && 232ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner AnalyzeIndirectGlobalMemory(I)) 233ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner ++NumIndirectGlobalVars; 2343b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 2353b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner Readers.clear(); Writers.clear(); 2363b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 2373b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 2383b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 239ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// AnalyzeUsesOfPointer - Look at all of the users of the specified pointer. 240ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// If this is used by anything complex (i.e., the address escapes), return 241ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// true. Also, while we are at it, keep track of those functions that read and 242ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// write to the value. 243ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// 244ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// If OkayStoreDest is non-null, stores into this global are allowed. 245ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattnerbool GlobalsModRef::AnalyzeUsesOfPointer(Value *V, 246ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner std::vector<Function*> &Readers, 247ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner std::vector<Function*> &Writers, 248ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GlobalValue *OkayStoreDest) { 2491df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands if (!V->getType()->isPointerTy()) return true; 2503b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 251d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif for (Value::use_iterator UI = V->use_begin(), E=V->use_end(); UI != E; ++UI) { 252d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif User *U = *UI; 253d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif if (LoadInst *LI = dyn_cast<LoadInst>(U)) { 2543b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner Readers.push_back(LI->getParent()->getParent()); 255d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) { 256ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (V == SI->getOperand(1)) { 257ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner Writers.push_back(SI->getParent()->getParent()); 258ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } else if (SI->getOperand(1) != OkayStoreDest) { 259ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return true; // Storing the pointer 260ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 261d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) { 262ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (AnalyzeUsesOfPointer(GEP, Readers, Writers)) return true; 263d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (BitCastInst *BCI = dyn_cast<BitCastInst>(U)) { 26446e8312fb733338e9af4db3757a1a8beddeae15aVictor Hernandez if (AnalyzeUsesOfPointer(BCI, Readers, Writers, OkayStoreDest)) 26546e8312fb733338e9af4db3757a1a8beddeae15aVictor Hernandez return true; 2668e0d1c03ca7fd86e6879b4e37d0d7f0e982feef6Benjamin Kramer } else if (isFreeCall(U, TLI)) { 267d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif Writers.push_back(cast<Instruction>(U)->getParent()->getParent()); 268d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (CallInst *CI = dyn_cast<CallInst>(U)) { 2693b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // Make sure that this is just the function being called, not that it is 2703b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // passing into the function. 27122a5b298201d62daea3e06718469d8ad017895e1Bill Wendling for (unsigned i = 0, e = CI->getNumArgOperands(); i != e; ++i) 27222a5b298201d62daea3e06718469d8ad017895e1Bill Wendling if (CI->getArgOperand(i) == V) return true; 273d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (InvokeInst *II = dyn_cast<InvokeInst>(U)) { 2743b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // Make sure that this is just the function being called, not that it is 2753b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // passing into the function. 27622a5b298201d62daea3e06718469d8ad017895e1Bill Wendling for (unsigned i = 0, e = II->getNumArgOperands(); i != e; ++i) 27722a5b298201d62daea3e06718469d8ad017895e1Bill Wendling if (II->getArgOperand(i) == V) return true; 278d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U)) { 2799a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (CE->getOpcode() == Instruction::GetElementPtr || 2803da59db637a887474c1b1346c1f3ccf53b6c4663Reid Spencer CE->getOpcode() == Instruction::BitCast) { 281ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (AnalyzeUsesOfPointer(CE, Readers, Writers)) 2823b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return true; 2833b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } else { 2843b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return true; 2852b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman } 286d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } else if (ICmpInst *ICI = dyn_cast<ICmpInst>(U)) { 287e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer if (!isa<ConstantPointerNull>(ICI->getOperand(1))) 288ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return true; // Allow comparison against null. 2893b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } else { 2903b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return true; 2913b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 292d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif } 293d7cc5215f131a4df933c750595d7c642df3ee5b8Gabor Greif 2943b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return false; 2953b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 2963b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 297ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// AnalyzeIndirectGlobalMemory - We found an non-address-taken global variable 298ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// which holds a pointer type. See if the global always points to non-aliased 299ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// heap memory: that is, all initializers of the globals are allocations, and 300ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// those allocations have no use other than initialization of the global. 301ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// Further, all loads out of GV must directly use the memory, not store the 302ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// pointer somewhere. If this is true, we consider the memory pointed to by 303ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner/// GV to be owned by GV and can disambiguate other pointers from it. 304ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattnerbool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) { 305ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Keep track of values related to the allocation of the memory, f.e. the 306ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // value produced by the malloc call and any casts. 307ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner std::vector<Value*> AllocRelatedValues; 3089a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 309ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Walk the user list of the global. If we find anything other than a direct 310ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // load or store, bail out. 311ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner for (Value::use_iterator I = GV->use_begin(), E = GV->use_end(); I != E; ++I){ 3128ba992ad527e50060083e83433b7125bbaa6b737Gabor Greif User *U = *I; 3138ba992ad527e50060083e83433b7125bbaa6b737Gabor Greif if (LoadInst *LI = dyn_cast<LoadInst>(U)) { 314ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // The pointer loaded from the global can only be used in simple ways: 315ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // we allow addressing of it and loading storing to it. We do *not* allow 316ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // storing the loaded pointer somewhere else or passing to a function. 317ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner std::vector<Function*> ReadersWriters; 318ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (AnalyzeUsesOfPointer(LI, ReadersWriters, ReadersWriters)) 319ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return false; // Loaded pointer escapes. 320ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // TODO: Could try some IP mod/ref of the loaded pointer. 3218ba992ad527e50060083e83433b7125bbaa6b737Gabor Greif } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) { 322ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Storing the global itself. 323ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (SI->getOperand(0) == GV) return false; 3249a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 325ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // If storing the null pointer, ignore it. 326ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (isa<ConstantPointerNull>(SI->getOperand(0))) 327ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner continue; 3289a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 329ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Check the value being stored. 3305034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman Value *Ptr = GetUnderlyingObject(SI->getOperand(0)); 331ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner 3328e0d1c03ca7fd86e6879b4e37d0d7f0e982feef6Benjamin Kramer if (!isAllocLikeFn(Ptr, TLI)) 333ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return false; // Too hard to analyze. 3349a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 335ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Analyze all uses of the allocation. If any of them are used in a 336ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // non-simple way (e.g. stored to another global) bail out. 337ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner std::vector<Function*> ReadersWriters; 338ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (AnalyzeUsesOfPointer(Ptr, ReadersWriters, ReadersWriters, GV)) 339ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return false; // Loaded pointer escapes. 340ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner 341ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Remember that this allocation is related to the indirect global. 342ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner AllocRelatedValues.push_back(Ptr); 343ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } else { 344ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Something complex, bail out. 345ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return false; 346ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 347ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 3489a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 349ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Okay, this is an indirect global. Remember all of the allocations for 350ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // this global in AllocsForIndirectGlobals. 351ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner while (!AllocRelatedValues.empty()) { 352ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner AllocsForIndirectGlobals[AllocRelatedValues.back()] = GV; 353ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner AllocRelatedValues.pop_back(); 354ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 355ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner IndirectGlobals.insert(GV); 356ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return true; 357ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner} 358ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner 3593b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// AnalyzeCallGraph - At this point, we know the functions where globals are 3603b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// immediately stored to and read from. Propagate this information up the call 361fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner/// graph to all callers and compute the mod/ref info for all memory for each 3622b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman/// function. 3633b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattnervoid GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) { 3643b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // We do a bottom-up SCC traversal of the call graph. In other words, we 3653b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // visit all callees before callers (leaf-first). 3669a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG); I != E; 3679a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands ++I) { 3689a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands std::vector<CallGraphNode *> &SCC = *I; 369f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands assert(!SCC.empty() && "SCC with no functions?"); 3709a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 371f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands if (!SCC[0]->getFunction()) { 372f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands // Calls externally - can't say anything useful. Remove any existing 373f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands // function records (may have been created when scanning globals). 374f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands for (unsigned i = 0, e = SCC.size(); i != e; ++i) 375f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands FunctionInfo.erase(SCC[i]->getFunction()); 37634f2a0ca17f00f9ce2081ee278685a007856fd90Duncan Sands continue; 377f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands } 378f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands 379f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands FunctionRecord &FR = FunctionInfo[SCC[0]->getFunction()]; 3803b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 3819a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands bool KnowNothing = false; 3829a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands unsigned FunctionEffect = 0; 3839a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 3849a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Collect the mod/ref properties due to called functions. We only compute 3859a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // one mod-ref set. 3869a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands for (unsigned i = 0, e = SCC.size(); i != e && !KnowNothing; ++i) { 3879a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands Function *F = SCC[i]->getFunction(); 3889a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (!F) { 3899a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands KnowNothing = true; 390fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner break; 3913b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner } 392fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 3939a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (F->isDeclaration()) { 3949a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Try to get mod/ref behaviour from function attributes. 395d0ac373660de64fe210e50458c7702432b3f9605Duncan Sands if (F->doesNotAccessMemory()) { 396d0ac373660de64fe210e50458c7702432b3f9605Duncan Sands // Can't do better than that! 397d0ac373660de64fe210e50458c7702432b3f9605Duncan Sands } else if (F->onlyReadsMemory()) { 3989a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands FunctionEffect |= Ref; 3992bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands if (!F->isIntrinsic()) 4001abe60b9be1b7b33e1fa422add5296d392831850Duncan Sands // This function might call back into the module and read a global - 4012bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands // consider every global as possibly being read by this function. 4022bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands FR.MayReadAnyGlobal = true; 403d0ac373660de64fe210e50458c7702432b3f9605Duncan Sands } else { 404892b84007c980e58181cd94fea7d70c5ed9642c8Duncan Sands FunctionEffect |= ModRef; 405892b84007c980e58181cd94fea7d70c5ed9642c8Duncan Sands // Can't say anything useful unless it's an intrinsic - they don't 406892b84007c980e58181cd94fea7d70c5ed9642c8Duncan Sands // read or write global variables of the kind considered here. 407892b84007c980e58181cd94fea7d70c5ed9642c8Duncan Sands KnowNothing = !F->isIntrinsic(); 4089a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4099a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands continue; 4109a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4119a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 4129a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands for (CallGraphNode::iterator CI = SCC[i]->begin(), E = SCC[i]->end(); 413f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands CI != E && !KnowNothing; ++CI) 4149a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (Function *Callee = CI->second->getFunction()) { 4159a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (FunctionRecord *CalleeFR = getFunctionInfo(Callee)) { 4169a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Propagate function effect up. 4179a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands FunctionEffect |= CalleeFR->FunctionEffect; 4189a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 4199a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Incorporate callee's effects on globals into our info. 42079fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman for (std::map<const GlobalValue*, unsigned>::iterator GI = 4219a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands CalleeFR->GlobalInfo.begin(), E = CalleeFR->GlobalInfo.end(); 4229a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands GI != E; ++GI) 423f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands FR.GlobalInfo[GI->first] |= GI->second; 4242bb4a4d31590c1d3c7b620d7ab6959af05920cd5Duncan Sands FR.MayReadAnyGlobal |= CalleeFR->MayReadAnyGlobal; 4259a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } else { 4269a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Can't say anything about it. However, if it is inside our SCC, 4279a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // then nothing needs to be done. 4289a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands CallGraphNode *CalleeNode = CG[Callee]; 4299a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (std::find(SCC.begin(), SCC.end(), CalleeNode) == SCC.end()) 4309a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands KnowNothing = true; 4319a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4329a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } else { 4339a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands KnowNothing = true; 4349a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4359a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4369a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 4379a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // If we can't say anything useful about this SCC, remove all SCC functions 4389a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // from the FunctionInfo map. 4399a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (KnowNothing) { 4409a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands for (unsigned i = 0, e = SCC.size(); i != e; ++i) 4419a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands FunctionInfo.erase(SCC[i]->getFunction()); 442b070beee77cf9a0befd06a4fdacb824b1da0b55aDuncan Sands continue; 4439a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4442b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman 4459a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Scan the function bodies for explicit loads or stores. 446fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner for (unsigned i = 0, e = SCC.size(); i != e && FunctionEffect != ModRef;++i) 447fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner for (inst_iterator II = inst_begin(SCC[i]->getFunction()), 4482b37d7cf28b1382420b5e4007042feeb66d21ac8Misha Brukman E = inst_end(SCC[i]->getFunction()); 449fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner II != E && FunctionEffect != ModRef; ++II) 4509e72a79ef4a9fcda482ce0b0e1f0bd6a4f16cffdNuno Lopes if (LoadInst *LI = dyn_cast<LoadInst>(&*II)) { 451fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner FunctionEffect |= Ref; 4529e72a79ef4a9fcda482ce0b0e1f0bd6a4f16cffdNuno Lopes if (LI->isVolatile()) 453b8ca4ff6439c1543a0c6729cbcd6c70c3be7dc3cDuncan Sands // Volatile loads may have side-effects, so mark them as writing 454b8ca4ff6439c1543a0c6729cbcd6c70c3be7dc3cDuncan Sands // memory (for example, a flag inside the processor). 455b8ca4ff6439c1543a0c6729cbcd6c70c3be7dc3cDuncan Sands FunctionEffect |= Mod; 4569e72a79ef4a9fcda482ce0b0e1f0bd6a4f16cffdNuno Lopes } else if (StoreInst *SI = dyn_cast<StoreInst>(&*II)) { 457fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner FunctionEffect |= Mod; 4589e72a79ef4a9fcda482ce0b0e1f0bd6a4f16cffdNuno Lopes if (SI->isVolatile()) 459b8ca4ff6439c1543a0c6729cbcd6c70c3be7dc3cDuncan Sands // Treat volatile stores as reading memory somewhere. 460b8ca4ff6439c1543a0c6729cbcd6c70c3be7dc3cDuncan Sands FunctionEffect |= Ref; 4618e0d1c03ca7fd86e6879b4e37d0d7f0e982feef6Benjamin Kramer } else if (isAllocationFn(&*II, TLI) || isFreeCall(&*II, TLI)) { 4623fe4d3cb5bd5ea7948faeed8451b61380d928808Chris Lattner FunctionEffect |= ModRef; 4638f3fabe0febb7335c4349d3d6081deca95419d48Rafael Espindola } else if (IntrinsicInst *Intrinsic = dyn_cast<IntrinsicInst>(&*II)) { 4648f3fabe0febb7335c4349d3d6081deca95419d48Rafael Espindola // The callgraph doesn't include intrinsic calls. 4658f3fabe0febb7335c4349d3d6081deca95419d48Rafael Espindola Function *Callee = Intrinsic->getCalledFunction(); 4668f3fabe0febb7335c4349d3d6081deca95419d48Rafael Espindola ModRefBehavior Behaviour = AliasAnalysis::getModRefBehavior(Callee); 4678f3fabe0febb7335c4349d3d6081deca95419d48Rafael Espindola FunctionEffect |= (Behaviour & ModRef); 468b8ca4ff6439c1543a0c6729cbcd6c70c3be7dc3cDuncan Sands } 469fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 4709a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if ((FunctionEffect & Mod) == 0) 4719a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands ++NumReadMemFunctions; 4729a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands if (FunctionEffect == 0) 4739a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands ++NumNoMemFunctions; 474f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands FR.FunctionEffect = FunctionEffect; 475fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner 4769a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // Finally, now that we know the full effect on this SCC, clone the 4779a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands // information to each function in the SCC. 4789a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands for (unsigned i = 1, e = SCC.size(); i != e; ++i) 479f423abc289bca6c0b0cbb3c28bfb2f844bc7398fDuncan Sands FunctionInfo[SCC[i]->getFunction()] = FR; 4809a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands } 4813b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 4823b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 4833b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 4843b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 4853b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// alias - If one of the pointers is to a global that we are tracking, and the 4863b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// other is some random pointer, we know there cannot be an alias, because the 4873b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner/// address of the global isn't taken. 4883b04a8ac455568f9b98ab7e9a43076260cb737aeChris LattnerAliasAnalysis::AliasResult 489b2143b6247901ae4eca2192ee134564c4f5f7853Dan GohmanGlobalsModRef::alias(const Location &LocA, 490b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman const Location &LocB) { 491ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Get the base object these pointers point to. 4925034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman const Value *UV1 = GetUnderlyingObject(LocA.Ptr); 4935034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman const Value *UV2 = GetUnderlyingObject(LocB.Ptr); 4949a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 495ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // If either of the underlying values is a global, they may be non-addr-taken 496ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // globals, which we can answer queries about. 49779fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman const GlobalValue *GV1 = dyn_cast<GlobalValue>(UV1); 49879fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman const GlobalValue *GV2 = dyn_cast<GlobalValue>(UV2); 499ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (GV1 || GV2) { 500ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // If the global's address is taken, pretend we don't know it's a pointer to 501ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // the global. 502ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (GV1 && !NonAddressTakenGlobals.count(GV1)) GV1 = 0; 503ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (GV2 && !NonAddressTakenGlobals.count(GV2)) GV2 = 0; 504ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner 505f451cb870efcf9e0302d25ed05f4cac6bb494e42Dan Gohman // If the two pointers are derived from two different non-addr-taken 506ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // globals, or if one is and the other isn't, we know these can't alias. 507ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if ((GV1 || GV2) && GV1 != GV2) 508ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner return NoAlias; 509ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner 510ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Otherwise if they are both derived from the same addr-taken global, we 511ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // can't know the two accesses don't overlap. 512ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 5139a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 514ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // These pointers may be based on the memory owned by an indirect global. If 515ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // so, we may be able to handle this. First check to see if the base pointer 516ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // is a direct load from an indirect global. 517ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GV1 = GV2 = 0; 51879fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman if (const LoadInst *LI = dyn_cast<LoadInst>(UV1)) 519ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0))) 520ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (IndirectGlobals.count(GV)) 521ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GV1 = GV; 52279fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman if (const LoadInst *LI = dyn_cast<LoadInst>(UV2)) 52379fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0))) 524ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (IndirectGlobals.count(GV)) 525ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GV2 = GV; 5269a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 527ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // These pointers may also be from an allocation for the indirect global. If 528ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // so, also handle them. 529ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (AllocsForIndirectGlobals.count(UV1)) 530ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GV1 = AllocsForIndirectGlobals[UV1]; 531ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (AllocsForIndirectGlobals.count(UV2)) 532ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner GV2 = AllocsForIndirectGlobals[UV2]; 5339a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 534ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Now that we know whether the two pointers are related to indirect globals, 535ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // use this to disambiguate the pointers. If either pointer is based on an 536ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // indirect global and if they are not both based on the same indirect global, 537ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // they cannot alias. 5383b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner if ((GV1 || GV2) && GV1 != GV2) 5393b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return NoAlias; 5409a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 541b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman return AliasAnalysis::alias(LocA, LocB); 5423b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 5433b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 5443b04a8ac455568f9b98ab7e9a43076260cb737aeChris LattnerAliasAnalysis::ModRefResult 54579fca6fea87be7221843031870bbf2c9ae1fc555Dan GohmanGlobalsModRef::getModRefInfo(ImmutableCallSite CS, 546b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman const Location &Loc) { 5473b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner unsigned Known = ModRef; 5483b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 5493b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner // If we are asking for mod/ref info of a direct call with a pointer to a 550fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner // global we are tracking, return information if we have it. 551b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman if (const GlobalValue *GV = 5525034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman dyn_cast<GlobalValue>(GetUnderlyingObject(Loc.Ptr))) 553bb46f52027416598a662dc1c58f48d9d56b1a65bRafael Espindola if (GV->hasLocalLinkage()) 55479fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman if (const Function *F = CS.getCalledFunction()) 555fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner if (NonAddressTakenGlobals.count(GV)) 55679fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman if (const FunctionRecord *FR = getFunctionInfo(F)) 557fe98f27e807b478d85240240cb19b6673aaaafb8Chris Lattner Known = FR->getInfoForGlobal(GV); 5583b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 5593b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner if (Known == NoModRef) 5603b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner return NoModRef; // No need to query other mod/ref analyses 561b2143b6247901ae4eca2192ee134564c4f5f7853Dan Gohman return ModRefResult(Known & AliasAnalysis::getModRefInfo(CS, Loc)); 5623b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 5633b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 5643b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 5653b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner//===----------------------------------------------------------------------===// 5663b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// Methods to update the analysis as a result of the client transformation. 5673b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner// 5683b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattnervoid GlobalsModRef::deleteValue(Value *V) { 569ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) { 570ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (NonAddressTakenGlobals.erase(GV)) { 571ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // This global might be an indirect global. If so, remove it and remove 572ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // any AllocRelatedValues for it. 573ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (IndirectGlobals.erase(GV)) { 574ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Remove any entries in AllocsForIndirectGlobals for this global. 57579fca6fea87be7221843031870bbf2c9ae1fc555Dan Gohman for (std::map<const Value*, const GlobalValue*>::iterator 576ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner I = AllocsForIndirectGlobals.begin(), 577ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner E = AllocsForIndirectGlobals.end(); I != E; ) { 578ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner if (I->second == GV) { 579ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner AllocsForIndirectGlobals.erase(I++); 580ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } else { 581ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner ++I; 582ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 583ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 584ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 585ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 586ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner } 5879a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 588ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // Otherwise, if this is an allocation related to an indirect global, remove 589ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner // it. 590ab38358fa08bcb4c7c1fc1409bc01408b49de933Chris Lattner AllocsForIndirectGlobals.erase(V); 5919a036b945c67aeb44093c6c515e4b85e21094335Duncan Sands 592cd883f203d23c7e44b12dff62df2e6d65d8f231cChris Lattner AliasAnalysis::deleteValue(V); 5933b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 5943b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner 5953b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattnervoid GlobalsModRef::copyValue(Value *From, Value *To) { 596cd883f203d23c7e44b12dff62df2e6d65d8f231cChris Lattner AliasAnalysis::copyValue(From, To); 5973b04a8ac455568f9b98ab7e9a43076260cb737aeChris Lattner} 598392249fcf368a22f48091a16c180160221c7e89aOwen Anderson 599392249fcf368a22f48091a16c180160221c7e89aOwen Andersonvoid GlobalsModRef::addEscapingUse(Use &U) { 600392249fcf368a22f48091a16c180160221c7e89aOwen Anderson // For the purposes of this analysis, it is conservatively correct to treat 601392249fcf368a22f48091a16c180160221c7e89aOwen Anderson // a newly escaping value equivalently to a deleted one. We could perhaps 602392249fcf368a22f48091a16c180160221c7e89aOwen Anderson // be more precise by processing the new use and attempting to update our 6037a2bdde0a0eebcd2125055e0eacaca040f0b766cChris Lattner // saved analysis results to accommodate it. 604392249fcf368a22f48091a16c180160221c7e89aOwen Anderson deleteValue(U); 605392249fcf368a22f48091a16c180160221c7e89aOwen Anderson 606392249fcf368a22f48091a16c180160221c7e89aOwen Anderson AliasAnalysis::addEscapingUse(U); 607392249fcf368a22f48091a16c180160221c7e89aOwen Anderson} 608