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			1705 lines
		
	
	
		
			54 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			1705 lines
		
	
	
		
			54 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===- FunctionAttrs.cpp - Pass which marks functions attributes ----------===//
 | |
| //
 | |
| //                     The LLVM Compiler Infrastructure
 | |
| //
 | |
| // This file is distributed under the University of Illinois Open Source
 | |
| // License. See LICENSE.TXT for details.
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
 | |
| //
 | |
| // This file implements a simple interprocedural pass which walks the
 | |
| // call-graph, looking for functions which do not access or only read
 | |
| // non-local memory, and marking them readnone/readonly.  It does the
 | |
| // same with function arguments independently, marking them readonly/
 | |
| // readnone/nocapture.  Finally, well-known library call declarations
 | |
| // are marked with all attributes that are consistent with the
 | |
| // function's standard definition. This pass is implemented as a
 | |
| // bottom-up traversal of the call-graph.
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
 | |
| 
 | |
| #include "llvm/Transforms/IPO.h"
 | |
| #include "llvm/ADT/SCCIterator.h"
 | |
| #include "llvm/ADT/SetVector.h"
 | |
| #include "llvm/ADT/SmallSet.h"
 | |
| #include "llvm/ADT/Statistic.h"
 | |
| #include "llvm/Analysis/AliasAnalysis.h"
 | |
| #include "llvm/Analysis/CallGraph.h"
 | |
| #include "llvm/Analysis/CallGraphSCCPass.h"
 | |
| #include "llvm/Analysis/CaptureTracking.h"
 | |
| #include "llvm/IR/GlobalVariable.h"
 | |
| #include "llvm/IR/InstIterator.h"
 | |
| #include "llvm/IR/IntrinsicInst.h"
 | |
| #include "llvm/IR/LLVMContext.h"
 | |
| #include "llvm/Target/TargetLibraryInfo.h"
 | |
| using namespace llvm;
 | |
| 
 | |
| #define DEBUG_TYPE "functionattrs"
 | |
| 
 | |
| STATISTIC(NumReadNone, "Number of functions marked readnone");
 | |
| STATISTIC(NumReadOnly, "Number of functions marked readonly");
 | |
| STATISTIC(NumNoCapture, "Number of arguments marked nocapture");
 | |
| STATISTIC(NumReadNoneArg, "Number of arguments marked readnone");
 | |
| STATISTIC(NumReadOnlyArg, "Number of arguments marked readonly");
 | |
| STATISTIC(NumNoAlias, "Number of function returns marked noalias");
 | |
| STATISTIC(NumAnnotated, "Number of attributes added to library functions");
 | |
| 
 | |
| namespace {
 | |
|   struct FunctionAttrs : public CallGraphSCCPass {
 | |
|     static char ID; // Pass identification, replacement for typeid
 | |
|     FunctionAttrs() : CallGraphSCCPass(ID), AA(nullptr) {
 | |
|       initializeFunctionAttrsPass(*PassRegistry::getPassRegistry());
 | |
|     }
 | |
| 
 | |
|     // runOnSCC - Analyze the SCC, performing the transformation if possible.
 | |
|     bool runOnSCC(CallGraphSCC &SCC) override;
 | |
| 
 | |
|     // AddReadAttrs - Deduce readonly/readnone attributes for the SCC.
 | |
|     bool AddReadAttrs(const CallGraphSCC &SCC);
 | |
| 
 | |
|     // AddArgumentAttrs - Deduce nocapture attributes for the SCC.
 | |
|     bool AddArgumentAttrs(const CallGraphSCC &SCC);
 | |
| 
 | |
|     // IsFunctionMallocLike - Does this function allocate new memory?
 | |
|     bool IsFunctionMallocLike(Function *F,
 | |
|                               SmallPtrSet<Function*, 8> &) const;
 | |
| 
 | |
|     // AddNoAliasAttrs - Deduce noalias attributes for the SCC.
 | |
|     bool AddNoAliasAttrs(const CallGraphSCC &SCC);
 | |
| 
 | |
|     // Utility methods used by inferPrototypeAttributes to add attributes
 | |
|     // and maintain annotation statistics.
 | |
| 
 | |
|     void setDoesNotAccessMemory(Function &F) {
 | |
|       if (!F.doesNotAccessMemory()) {
 | |
|         F.setDoesNotAccessMemory();
 | |
|         ++NumAnnotated;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     void setOnlyReadsMemory(Function &F) {
 | |
|       if (!F.onlyReadsMemory()) {
 | |
|         F.setOnlyReadsMemory();
 | |
|         ++NumAnnotated;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     void setDoesNotThrow(Function &F) {
 | |
|       if (!F.doesNotThrow()) {
 | |
|         F.setDoesNotThrow();
 | |
|         ++NumAnnotated;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     void setDoesNotCapture(Function &F, unsigned n) {
 | |
|       if (!F.doesNotCapture(n)) {
 | |
|         F.setDoesNotCapture(n);
 | |
|         ++NumAnnotated;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     void setOnlyReadsMemory(Function &F, unsigned n) {
 | |
|       if (!F.onlyReadsMemory(n)) {
 | |
|         F.setOnlyReadsMemory(n);
 | |
|         ++NumAnnotated;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     void setDoesNotAlias(Function &F, unsigned n) {
 | |
|       if (!F.doesNotAlias(n)) {
 | |
|         F.setDoesNotAlias(n);
 | |
|         ++NumAnnotated;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     // inferPrototypeAttributes - Analyze the name and prototype of the
 | |
|     // given function and set any applicable attributes.  Returns true
 | |
|     // if any attributes were set and false otherwise.
 | |
|     bool inferPrototypeAttributes(Function &F);
 | |
| 
 | |
|     // annotateLibraryCalls - Adds attributes to well-known standard library
 | |
|     // call declarations.
 | |
|     bool annotateLibraryCalls(const CallGraphSCC &SCC);
 | |
| 
 | |
|     void getAnalysisUsage(AnalysisUsage &AU) const override {
 | |
|       AU.setPreservesCFG();
 | |
|       AU.addRequired<AliasAnalysis>();
 | |
|       AU.addRequired<TargetLibraryInfo>();
 | |
|       CallGraphSCCPass::getAnalysisUsage(AU);
 | |
|     }
 | |
| 
 | |
|   private:
 | |
|     AliasAnalysis *AA;
 | |
|     TargetLibraryInfo *TLI;
 | |
|   };
 | |
| }
 | |
| 
 | |
| char FunctionAttrs::ID = 0;
 | |
| INITIALIZE_PASS_BEGIN(FunctionAttrs, "functionattrs",
 | |
|                 "Deduce function attributes", false, false)
 | |
| INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 | |
| INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
 | |
| INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
 | |
| INITIALIZE_PASS_END(FunctionAttrs, "functionattrs",
 | |
|                 "Deduce function attributes", false, false)
 | |
| 
 | |
| Pass *llvm::createFunctionAttrsPass() { return new FunctionAttrs(); }
 | |
| 
 | |
| 
 | |
| /// AddReadAttrs - Deduce readonly/readnone attributes for the SCC.
 | |
| bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
 | |
|   SmallPtrSet<Function*, 8> SCCNodes;
 | |
| 
 | |
|   // Fill SCCNodes with the elements of the SCC.  Used for quickly
 | |
|   // looking up whether a given CallGraphNode is in this SCC.
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
 | |
|     SCCNodes.insert((*I)->getFunction());
 | |
| 
 | |
|   // Check if any of the functions in the SCC read or write memory.  If they
 | |
|   // write memory then they can't be marked readnone or readonly.
 | |
|   bool ReadsMemory = false;
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
| 
 | |
|     if (!F)
 | |
|       // External node - may write memory.  Just give up.
 | |
|       return false;
 | |
| 
 | |
|     AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(F);
 | |
|     if (MRB == AliasAnalysis::DoesNotAccessMemory)
 | |
|       // Already perfect!
 | |
|       continue;
 | |
| 
 | |
|     // Definitions with weak linkage may be overridden at linktime with
 | |
|     // something that writes memory, so treat them like declarations.
 | |
|     if (F->isDeclaration() || F->mayBeOverridden()) {
 | |
|       if (!AliasAnalysis::onlyReadsMemory(MRB))
 | |
|         // May write memory.  Just give up.
 | |
|         return false;
 | |
| 
 | |
|       ReadsMemory = true;
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     // Scan the function body for instructions that may read or write memory.
 | |
|     for (inst_iterator II = inst_begin(F), E = inst_end(F); II != E; ++II) {
 | |
|       Instruction *I = &*II;
 | |
| 
 | |
|       // Some instructions can be ignored even if they read or write memory.
 | |
|       // Detect these now, skipping to the next instruction if one is found.
 | |
|       CallSite CS(cast<Value>(I));
 | |
|       if (CS) {
 | |
|         // Ignore calls to functions in the same SCC.
 | |
|         if (CS.getCalledFunction() && SCCNodes.count(CS.getCalledFunction()))
 | |
|           continue;
 | |
|         AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(CS);
 | |
|         // If the call doesn't access arbitrary memory, we may be able to
 | |
|         // figure out something.
 | |
|         if (AliasAnalysis::onlyAccessesArgPointees(MRB)) {
 | |
|           // If the call does access argument pointees, check each argument.
 | |
|           if (AliasAnalysis::doesAccessArgPointees(MRB))
 | |
|             // Check whether all pointer arguments point to local memory, and
 | |
|             // ignore calls that only access local memory.
 | |
|             for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
 | |
|                  CI != CE; ++CI) {
 | |
|               Value *Arg = *CI;
 | |
|               if (Arg->getType()->isPointerTy()) {
 | |
|                 AliasAnalysis::Location Loc(Arg,
 | |
|                                             AliasAnalysis::UnknownSize,
 | |
|                                             I->getMetadata(LLVMContext::MD_tbaa));
 | |
|                 if (!AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) {
 | |
|                   if (MRB & AliasAnalysis::Mod)
 | |
|                     // Writes non-local memory.  Give up.
 | |
|                     return false;
 | |
|                   if (MRB & AliasAnalysis::Ref)
 | |
|                     // Ok, it reads non-local memory.
 | |
|                     ReadsMemory = true;
 | |
|                 }
 | |
|               }
 | |
|             }
 | |
|           continue;
 | |
|         }
 | |
|         // The call could access any memory. If that includes writes, give up.
 | |
|         if (MRB & AliasAnalysis::Mod)
 | |
|           return false;
 | |
|         // If it reads, note it.
 | |
|         if (MRB & AliasAnalysis::Ref)
 | |
|           ReadsMemory = true;
 | |
|         continue;
 | |
|       } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 | |
|         // Ignore non-volatile loads from local memory. (Atomic is okay here.)
 | |
|         if (!LI->isVolatile()) {
 | |
|           AliasAnalysis::Location Loc = AA->getLocation(LI);
 | |
|           if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
 | |
|             continue;
 | |
|         }
 | |
|       } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 | |
|         // Ignore non-volatile stores to local memory. (Atomic is okay here.)
 | |
|         if (!SI->isVolatile()) {
 | |
|           AliasAnalysis::Location Loc = AA->getLocation(SI);
 | |
|           if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
 | |
|             continue;
 | |
|         }
 | |
|       } else if (VAArgInst *VI = dyn_cast<VAArgInst>(I)) {
 | |
|         // Ignore vaargs on local memory.
 | |
|         AliasAnalysis::Location Loc = AA->getLocation(VI);
 | |
|         if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
 | |
|           continue;
 | |
|       }
 | |
| 
 | |
|       // Any remaining instructions need to be taken seriously!  Check if they
 | |
|       // read or write memory.
 | |
|       if (I->mayWriteToMemory())
 | |
|         // Writes memory.  Just give up.
 | |
|         return false;
 | |
| 
 | |
|       // If this instruction may read memory, remember that.
 | |
|       ReadsMemory |= I->mayReadFromMemory();
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Success!  Functions in this SCC do not access memory, or only read memory.
 | |
|   // Give them the appropriate attribute.
 | |
|   bool MadeChange = false;
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
| 
 | |
|     if (F->doesNotAccessMemory())
 | |
|       // Already perfect!
 | |
|       continue;
 | |
| 
 | |
|     if (F->onlyReadsMemory() && ReadsMemory)
 | |
|       // No change.
 | |
|       continue;
 | |
| 
 | |
|     MadeChange = true;
 | |
| 
 | |
|     // Clear out any existing attributes.
 | |
|     AttrBuilder B;
 | |
|     B.addAttribute(Attribute::ReadOnly)
 | |
|       .addAttribute(Attribute::ReadNone);
 | |
|     F->removeAttributes(AttributeSet::FunctionIndex,
 | |
|                         AttributeSet::get(F->getContext(),
 | |
|                                           AttributeSet::FunctionIndex, B));
 | |
| 
 | |
|     // Add in the new attribute.
 | |
|     F->addAttribute(AttributeSet::FunctionIndex,
 | |
|                     ReadsMemory ? Attribute::ReadOnly : Attribute::ReadNone);
 | |
| 
 | |
|     if (ReadsMemory)
 | |
|       ++NumReadOnly;
 | |
|     else
 | |
|       ++NumReadNone;
 | |
|   }
 | |
| 
 | |
|   return MadeChange;
 | |
| }
 | |
| 
 | |
| namespace {
 | |
|   // For a given pointer Argument, this retains a list of Arguments of functions
 | |
|   // in the same SCC that the pointer data flows into. We use this to build an
 | |
|   // SCC of the arguments.
 | |
|   struct ArgumentGraphNode {
 | |
|     Argument *Definition;
 | |
|     SmallVector<ArgumentGraphNode*, 4> Uses;
 | |
|   };
 | |
| 
 | |
|   class ArgumentGraph {
 | |
|     // We store pointers to ArgumentGraphNode objects, so it's important that
 | |
|     // that they not move around upon insert.
 | |
|     typedef std::map<Argument*, ArgumentGraphNode> ArgumentMapTy;
 | |
| 
 | |
|     ArgumentMapTy ArgumentMap;
 | |
| 
 | |
|     // There is no root node for the argument graph, in fact:
 | |
|     //   void f(int *x, int *y) { if (...) f(x, y); }
 | |
|     // is an example where the graph is disconnected. The SCCIterator requires a
 | |
|     // single entry point, so we maintain a fake ("synthetic") root node that
 | |
|     // uses every node. Because the graph is directed and nothing points into
 | |
|     // the root, it will not participate in any SCCs (except for its own).
 | |
|     ArgumentGraphNode SyntheticRoot;
 | |
| 
 | |
|   public:
 | |
|     ArgumentGraph() { SyntheticRoot.Definition = nullptr; }
 | |
| 
 | |
|     typedef SmallVectorImpl<ArgumentGraphNode*>::iterator iterator;
 | |
| 
 | |
|     iterator begin() { return SyntheticRoot.Uses.begin(); }
 | |
|     iterator end() { return SyntheticRoot.Uses.end(); }
 | |
|     ArgumentGraphNode *getEntryNode() { return &SyntheticRoot; }
 | |
| 
 | |
|     ArgumentGraphNode *operator[](Argument *A) {
 | |
|       ArgumentGraphNode &Node = ArgumentMap[A];
 | |
|       Node.Definition = A;
 | |
|       SyntheticRoot.Uses.push_back(&Node);
 | |
|       return &Node;
 | |
|     }
 | |
|   };
 | |
| 
 | |
|   // This tracker checks whether callees are in the SCC, and if so it does not
 | |
|   // consider that a capture, instead adding it to the "Uses" list and
 | |
|   // continuing with the analysis.
 | |
|   struct ArgumentUsesTracker : public CaptureTracker {
 | |
|     ArgumentUsesTracker(const SmallPtrSet<Function*, 8> &SCCNodes)
 | |
|       : Captured(false), SCCNodes(SCCNodes) {}
 | |
| 
 | |
|     void tooManyUses() override { Captured = true; }
 | |
| 
 | |
|     bool captured(const Use *U) override {
 | |
|       CallSite CS(U->getUser());
 | |
|       if (!CS.getInstruction()) { Captured = true; return true; }
 | |
| 
 | |
|       Function *F = CS.getCalledFunction();
 | |
|       if (!F || !SCCNodes.count(F)) { Captured = true; return true; }
 | |
| 
 | |
|       bool Found = false;
 | |
|       Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
 | |
|       for (CallSite::arg_iterator PI = CS.arg_begin(), PE = CS.arg_end();
 | |
|            PI != PE; ++PI, ++AI) {
 | |
|         if (AI == AE) {
 | |
|           assert(F->isVarArg() && "More params than args in non-varargs call");
 | |
|           Captured = true;
 | |
|           return true;
 | |
|         }
 | |
|         if (PI == U) {
 | |
|           Uses.push_back(AI);
 | |
|           Found = true;
 | |
|           break;
 | |
|         }
 | |
|       }
 | |
|       assert(Found && "Capturing call-site captured nothing?");
 | |
|       (void)Found;
 | |
|       return false;
 | |
|     }
 | |
| 
 | |
|     bool Captured;  // True only if certainly captured (used outside our SCC).
 | |
|     SmallVector<Argument*, 4> Uses;  // Uses within our SCC.
 | |
| 
 | |
|     const SmallPtrSet<Function*, 8> &SCCNodes;
 | |
|   };
 | |
| }
 | |
| 
 | |
| namespace llvm {
 | |
|   template<> struct GraphTraits<ArgumentGraphNode*> {
 | |
|     typedef ArgumentGraphNode NodeType;
 | |
|     typedef SmallVectorImpl<ArgumentGraphNode*>::iterator ChildIteratorType;
 | |
| 
 | |
|     static inline NodeType *getEntryNode(NodeType *A) { return A; }
 | |
|     static inline ChildIteratorType child_begin(NodeType *N) {
 | |
|       return N->Uses.begin();
 | |
|     }
 | |
|     static inline ChildIteratorType child_end(NodeType *N) {
 | |
|       return N->Uses.end();
 | |
|     }
 | |
|   };
 | |
|   template<> struct GraphTraits<ArgumentGraph*>
 | |
|     : public GraphTraits<ArgumentGraphNode*> {
 | |
|     static NodeType *getEntryNode(ArgumentGraph *AG) {
 | |
|       return AG->getEntryNode();
 | |
|     }
 | |
|     static ChildIteratorType nodes_begin(ArgumentGraph *AG) {
 | |
|       return AG->begin();
 | |
|     }
 | |
|     static ChildIteratorType nodes_end(ArgumentGraph *AG) {
 | |
|       return AG->end();
 | |
|     }
 | |
|   };
 | |
| }
 | |
| 
 | |
| // Returns Attribute::None, Attribute::ReadOnly or Attribute::ReadNone.
 | |
| static Attribute::AttrKind
 | |
| determinePointerReadAttrs(Argument *A,
 | |
|                           const SmallPtrSet<Argument*, 8> &SCCNodes) {
 | |
|                                                        
 | |
|   SmallVector<Use*, 32> Worklist;
 | |
|   SmallSet<Use*, 32> Visited;
 | |
|   int Count = 0;
 | |
| 
 | |
|   // inalloca arguments are always clobbered by the call.
 | |
|   if (A->hasInAllocaAttr())
 | |
|     return Attribute::None;
 | |
| 
 | |
|   bool IsRead = false;
 | |
|   // We don't need to track IsWritten. If A is written to, return immediately.
 | |
| 
 | |
|   for (Use &U : A->uses()) {
 | |
|     if (Count++ >= 20)
 | |
|       return Attribute::None;
 | |
| 
 | |
|     Visited.insert(&U);
 | |
|     Worklist.push_back(&U);
 | |
|   }
 | |
| 
 | |
|   while (!Worklist.empty()) {
 | |
|     Use *U = Worklist.pop_back_val();
 | |
|     Instruction *I = cast<Instruction>(U->getUser());
 | |
|     Value *V = U->get();
 | |
| 
 | |
|     switch (I->getOpcode()) {
 | |
|     case Instruction::BitCast:
 | |
|     case Instruction::GetElementPtr:
 | |
|     case Instruction::PHI:
 | |
|     case Instruction::Select:
 | |
|     case Instruction::AddrSpaceCast:
 | |
|       // The original value is not read/written via this if the new value isn't.
 | |
|       for (Use &UU : I->uses())
 | |
|         if (Visited.insert(&UU))
 | |
|           Worklist.push_back(&UU);
 | |
|       break;
 | |
| 
 | |
|     case Instruction::Call:
 | |
|     case Instruction::Invoke: {
 | |
|       bool Captures = true;
 | |
| 
 | |
|       if (I->getType()->isVoidTy())
 | |
|         Captures = false;
 | |
| 
 | |
|       auto AddUsersToWorklistIfCapturing = [&] {
 | |
|         if (Captures)
 | |
|           for (Use &UU : I->uses())
 | |
|             if (Visited.insert(&UU))
 | |
|               Worklist.push_back(&UU);
 | |
|       };
 | |
| 
 | |
|       CallSite CS(I);
 | |
|       if (CS.doesNotAccessMemory()) {
 | |
|         AddUsersToWorklistIfCapturing();
 | |
|         continue;
 | |
|       }
 | |
| 
 | |
|       Function *F = CS.getCalledFunction();
 | |
|       if (!F) {
 | |
|         if (CS.onlyReadsMemory()) {
 | |
|           IsRead = true;
 | |
|           AddUsersToWorklistIfCapturing();
 | |
|           continue;
 | |
|         }
 | |
|         return Attribute::None;
 | |
|       }
 | |
| 
 | |
|       Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
 | |
|       CallSite::arg_iterator B = CS.arg_begin(), E = CS.arg_end();
 | |
|       for (CallSite::arg_iterator A = B; A != E; ++A, ++AI) {
 | |
|         if (A->get() == V) {
 | |
|           if (AI == AE) {
 | |
|             assert(F->isVarArg() &&
 | |
|                    "More params than args in non-varargs call.");
 | |
|             return Attribute::None;
 | |
|           }
 | |
|           Captures &= !CS.doesNotCapture(A - B);
 | |
|           if (SCCNodes.count(AI))
 | |
|             continue;
 | |
|           if (!CS.onlyReadsMemory() && !CS.onlyReadsMemory(A - B))
 | |
|             return Attribute::None;
 | |
|           if (!CS.doesNotAccessMemory(A - B))
 | |
|             IsRead = true;
 | |
|         }
 | |
|       }
 | |
|       AddUsersToWorklistIfCapturing();
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     case Instruction::Load:
 | |
|       IsRead = true;
 | |
|       break;
 | |
| 
 | |
|     case Instruction::ICmp:
 | |
|     case Instruction::Ret:
 | |
|       break;
 | |
| 
 | |
|     default:
 | |
|       return Attribute::None;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   return IsRead ? Attribute::ReadOnly : Attribute::ReadNone;
 | |
| }
 | |
| 
 | |
| /// AddArgumentAttrs - Deduce nocapture attributes for the SCC.
 | |
| bool FunctionAttrs::AddArgumentAttrs(const CallGraphSCC &SCC) {
 | |
|   bool Changed = false;
 | |
| 
 | |
|   SmallPtrSet<Function*, 8> SCCNodes;
 | |
| 
 | |
|   // Fill SCCNodes with the elements of the SCC.  Used for quickly
 | |
|   // looking up whether a given CallGraphNode is in this SCC.
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
|     if (F && !F->isDeclaration() && !F->mayBeOverridden())
 | |
|       SCCNodes.insert(F);
 | |
|   }
 | |
| 
 | |
|   ArgumentGraph AG;
 | |
| 
 | |
|   AttrBuilder B;
 | |
|   B.addAttribute(Attribute::NoCapture);
 | |
| 
 | |
|   // Check each function in turn, determining which pointer arguments are not
 | |
|   // captured.
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
| 
 | |
|     if (!F)
 | |
|       // External node - only a problem for arguments that we pass to it.
 | |
|       continue;
 | |
| 
 | |
|     // Definitions with weak linkage may be overridden at linktime with
 | |
|     // something that captures pointers, so treat them like declarations.
 | |
|     if (F->isDeclaration() || F->mayBeOverridden())
 | |
|       continue;
 | |
| 
 | |
|     // Functions that are readonly (or readnone) and nounwind and don't return
 | |
|     // a value can't capture arguments. Don't analyze them.
 | |
|     if (F->onlyReadsMemory() && F->doesNotThrow() &&
 | |
|         F->getReturnType()->isVoidTy()) {
 | |
|       for (Function::arg_iterator A = F->arg_begin(), E = F->arg_end();
 | |
|            A != E; ++A) {
 | |
|         if (A->getType()->isPointerTy() && !A->hasNoCaptureAttr()) {
 | |
|           A->addAttr(AttributeSet::get(F->getContext(), A->getArgNo() + 1, B));
 | |
|           ++NumNoCapture;
 | |
|           Changed = true;
 | |
|         }
 | |
|       }
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     for (Function::arg_iterator A = F->arg_begin(), E = F->arg_end();
 | |
|          A != E; ++A) {
 | |
|       if (!A->getType()->isPointerTy()) continue;
 | |
|       bool HasNonLocalUses = false;
 | |
|       if (!A->hasNoCaptureAttr()) {
 | |
|         ArgumentUsesTracker Tracker(SCCNodes);
 | |
|         PointerMayBeCaptured(A, &Tracker);
 | |
|         if (!Tracker.Captured) {
 | |
|           if (Tracker.Uses.empty()) {
 | |
|             // If it's trivially not captured, mark it nocapture now.
 | |
|             A->addAttr(AttributeSet::get(F->getContext(), A->getArgNo()+1, B));
 | |
|             ++NumNoCapture;
 | |
|             Changed = true;
 | |
|           } else {
 | |
|             // If it's not trivially captured and not trivially not captured,
 | |
|             // then it must be calling into another function in our SCC. Save
 | |
|             // its particulars for Argument-SCC analysis later.
 | |
|             ArgumentGraphNode *Node = AG[A];
 | |
|             for (SmallVectorImpl<Argument*>::iterator UI = Tracker.Uses.begin(),
 | |
|                      UE = Tracker.Uses.end(); UI != UE; ++UI) {
 | |
|               Node->Uses.push_back(AG[*UI]);
 | |
|               if (*UI != A)
 | |
|                 HasNonLocalUses = true;
 | |
|             }
 | |
|           }
 | |
|         }
 | |
|         // Otherwise, it's captured. Don't bother doing SCC analysis on it.
 | |
|       }
 | |
|       if (!HasNonLocalUses && !A->onlyReadsMemory()) {
 | |
|         // Can we determine that it's readonly/readnone without doing an SCC?
 | |
|         // Note that we don't allow any calls at all here, or else our result
 | |
|         // will be dependent on the iteration order through the functions in the
 | |
|         // SCC.
 | |
|         SmallPtrSet<Argument*, 8> Self;
 | |
|         Self.insert(A);
 | |
|         Attribute::AttrKind R = determinePointerReadAttrs(A, Self);
 | |
|         if (R != Attribute::None) {
 | |
|           AttrBuilder B;
 | |
|           B.addAttribute(R);
 | |
|           A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
 | |
|           Changed = true;
 | |
|           R == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg;
 | |
|         }
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // The graph we've collected is partial because we stopped scanning for
 | |
|   // argument uses once we solved the argument trivially. These partial nodes
 | |
|   // show up as ArgumentGraphNode objects with an empty Uses list, and for
 | |
|   // these nodes the final decision about whether they capture has already been
 | |
|   // made.  If the definition doesn't have a 'nocapture' attribute by now, it
 | |
|   // captures.
 | |
| 
 | |
|   for (scc_iterator<ArgumentGraph*> I = scc_begin(&AG); !I.isAtEnd(); ++I) {
 | |
|     const std::vector<ArgumentGraphNode *> &ArgumentSCC = *I;
 | |
|     if (ArgumentSCC.size() == 1) {
 | |
|       if (!ArgumentSCC[0]->Definition) continue;  // synthetic root node
 | |
| 
 | |
|       // eg. "void f(int* x) { if (...) f(x); }"
 | |
|       if (ArgumentSCC[0]->Uses.size() == 1 &&
 | |
|           ArgumentSCC[0]->Uses[0] == ArgumentSCC[0]) {
 | |
|         Argument *A = ArgumentSCC[0]->Definition;
 | |
|         A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
 | |
|         ++NumNoCapture;
 | |
|         Changed = true;
 | |
|       }
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     bool SCCCaptured = false;
 | |
|     for (auto I = ArgumentSCC.begin(), E = ArgumentSCC.end();
 | |
|          I != E && !SCCCaptured; ++I) {
 | |
|       ArgumentGraphNode *Node = *I;
 | |
|       if (Node->Uses.empty()) {
 | |
|         if (!Node->Definition->hasNoCaptureAttr())
 | |
|           SCCCaptured = true;
 | |
|       }
 | |
|     }
 | |
|     if (SCCCaptured) continue;
 | |
| 
 | |
|     SmallPtrSet<Argument*, 8> ArgumentSCCNodes;
 | |
|     // Fill ArgumentSCCNodes with the elements of the ArgumentSCC.  Used for
 | |
|     // quickly looking up whether a given Argument is in this ArgumentSCC.
 | |
|     for (auto I = ArgumentSCC.begin(), E = ArgumentSCC.end(); I != E; ++I) {
 | |
|       ArgumentSCCNodes.insert((*I)->Definition);
 | |
|     }
 | |
| 
 | |
|     for (auto I = ArgumentSCC.begin(), E = ArgumentSCC.end();
 | |
|          I != E && !SCCCaptured; ++I) {
 | |
|       ArgumentGraphNode *N = *I;
 | |
|       for (SmallVectorImpl<ArgumentGraphNode*>::iterator UI = N->Uses.begin(),
 | |
|              UE = N->Uses.end(); UI != UE; ++UI) {
 | |
|         Argument *A = (*UI)->Definition;
 | |
|         if (A->hasNoCaptureAttr() || ArgumentSCCNodes.count(A))
 | |
|           continue;
 | |
|         SCCCaptured = true;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|     if (SCCCaptured) continue;
 | |
| 
 | |
|     for (unsigned i = 0, e = ArgumentSCC.size(); i != e; ++i) {
 | |
|       Argument *A = ArgumentSCC[i]->Definition;
 | |
|       A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
 | |
|       ++NumNoCapture;
 | |
|       Changed = true;
 | |
|     }
 | |
| 
 | |
|     // We also want to compute readonly/readnone. With a small number of false
 | |
|     // negatives, we can assume that any pointer which is captured isn't going
 | |
|     // to be provably readonly or readnone, since by definition we can't
 | |
|     // analyze all uses of a captured pointer.
 | |
|     //
 | |
|     // The false negatives happen when the pointer is captured by a function
 | |
|     // that promises readonly/readnone behaviour on the pointer, then the
 | |
|     // pointer's lifetime ends before anything that writes to arbitrary memory.
 | |
|     // Also, a readonly/readnone pointer may be returned, but returning a
 | |
|     // pointer is capturing it.
 | |
| 
 | |
|     Attribute::AttrKind ReadAttr = Attribute::ReadNone;
 | |
|     for (unsigned i = 0, e = ArgumentSCC.size(); i != e; ++i) {
 | |
|       Argument *A = ArgumentSCC[i]->Definition;
 | |
|       Attribute::AttrKind K = determinePointerReadAttrs(A, ArgumentSCCNodes);
 | |
|       if (K == Attribute::ReadNone)
 | |
|         continue;
 | |
|       if (K == Attribute::ReadOnly) {
 | |
|         ReadAttr = Attribute::ReadOnly;
 | |
|         continue;
 | |
|       }
 | |
|       ReadAttr = K;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     if (ReadAttr != Attribute::None) {
 | |
|       AttrBuilder B;
 | |
|       B.addAttribute(ReadAttr);
 | |
|       for (unsigned i = 0, e = ArgumentSCC.size(); i != e; ++i) {
 | |
|         Argument *A = ArgumentSCC[i]->Definition;
 | |
|         A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
 | |
|         ReadAttr == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg;
 | |
|         Changed = true;
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   return Changed;
 | |
| }
 | |
| 
 | |
| /// IsFunctionMallocLike - A function is malloc-like if it returns either null
 | |
| /// or a pointer that doesn't alias any other pointer visible to the caller.
 | |
| bool FunctionAttrs::IsFunctionMallocLike(Function *F,
 | |
|                               SmallPtrSet<Function*, 8> &SCCNodes) const {
 | |
|   SmallSetVector<Value *, 8> FlowsToReturn;
 | |
|   for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
 | |
|     if (ReturnInst *Ret = dyn_cast<ReturnInst>(I->getTerminator()))
 | |
|       FlowsToReturn.insert(Ret->getReturnValue());
 | |
| 
 | |
|   for (unsigned i = 0; i != FlowsToReturn.size(); ++i) {
 | |
|     Value *RetVal = FlowsToReturn[i];
 | |
| 
 | |
|     if (Constant *C = dyn_cast<Constant>(RetVal)) {
 | |
|       if (!C->isNullValue() && !isa<UndefValue>(C))
 | |
|         return false;
 | |
| 
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     if (isa<Argument>(RetVal))
 | |
|       return false;
 | |
| 
 | |
|     if (Instruction *RVI = dyn_cast<Instruction>(RetVal))
 | |
|       switch (RVI->getOpcode()) {
 | |
|         // Extend the analysis by looking upwards.
 | |
|         case Instruction::BitCast:
 | |
|         case Instruction::GetElementPtr:
 | |
|         case Instruction::AddrSpaceCast:
 | |
|           FlowsToReturn.insert(RVI->getOperand(0));
 | |
|           continue;
 | |
|         case Instruction::Select: {
 | |
|           SelectInst *SI = cast<SelectInst>(RVI);
 | |
|           FlowsToReturn.insert(SI->getTrueValue());
 | |
|           FlowsToReturn.insert(SI->getFalseValue());
 | |
|           continue;
 | |
|         }
 | |
|         case Instruction::PHI: {
 | |
|           PHINode *PN = cast<PHINode>(RVI);
 | |
|           for (int i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
 | |
|             FlowsToReturn.insert(PN->getIncomingValue(i));
 | |
|           continue;
 | |
|         }
 | |
| 
 | |
|         // Check whether the pointer came from an allocation.
 | |
|         case Instruction::Alloca:
 | |
|           break;
 | |
|         case Instruction::Call:
 | |
|         case Instruction::Invoke: {
 | |
|           CallSite CS(RVI);
 | |
|           if (CS.paramHasAttr(0, Attribute::NoAlias))
 | |
|             break;
 | |
|           if (CS.getCalledFunction() &&
 | |
|               SCCNodes.count(CS.getCalledFunction()))
 | |
|             break;
 | |
|         } // fall-through
 | |
|         default:
 | |
|           return false;  // Did not come from an allocation.
 | |
|       }
 | |
| 
 | |
|     if (PointerMayBeCaptured(RetVal, false, /*StoreCaptures=*/false))
 | |
|       return false;
 | |
|   }
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| /// AddNoAliasAttrs - Deduce noalias attributes for the SCC.
 | |
| bool FunctionAttrs::AddNoAliasAttrs(const CallGraphSCC &SCC) {
 | |
|   SmallPtrSet<Function*, 8> SCCNodes;
 | |
| 
 | |
|   // Fill SCCNodes with the elements of the SCC.  Used for quickly
 | |
|   // looking up whether a given CallGraphNode is in this SCC.
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
 | |
|     SCCNodes.insert((*I)->getFunction());
 | |
| 
 | |
|   // Check each function in turn, determining which functions return noalias
 | |
|   // pointers.
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
| 
 | |
|     if (!F)
 | |
|       // External node - skip it;
 | |
|       return false;
 | |
| 
 | |
|     // Already noalias.
 | |
|     if (F->doesNotAlias(0))
 | |
|       continue;
 | |
| 
 | |
|     // Definitions with weak linkage may be overridden at linktime, so
 | |
|     // treat them like declarations.
 | |
|     if (F->isDeclaration() || F->mayBeOverridden())
 | |
|       return false;
 | |
| 
 | |
|     // We annotate noalias return values, which are only applicable to 
 | |
|     // pointer types.
 | |
|     if (!F->getReturnType()->isPointerTy())
 | |
|       continue;
 | |
| 
 | |
|     if (!IsFunctionMallocLike(F, SCCNodes))
 | |
|       return false;
 | |
|   }
 | |
| 
 | |
|   bool MadeChange = false;
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
|     if (F->doesNotAlias(0) || !F->getReturnType()->isPointerTy())
 | |
|       continue;
 | |
| 
 | |
|     F->setDoesNotAlias(0);
 | |
|     ++NumNoAlias;
 | |
|     MadeChange = true;
 | |
|   }
 | |
| 
 | |
|   return MadeChange;
 | |
| }
 | |
| 
 | |
| /// inferPrototypeAttributes - Analyze the name and prototype of the
 | |
| /// given function and set any applicable attributes.  Returns true
 | |
| /// if any attributes were set and false otherwise.
 | |
| bool FunctionAttrs::inferPrototypeAttributes(Function &F) {
 | |
|   FunctionType *FTy = F.getFunctionType();
 | |
|   LibFunc::Func TheLibFunc;
 | |
|   if (!(TLI->getLibFunc(F.getName(), TheLibFunc) && TLI->has(TheLibFunc)))
 | |
|     return false;
 | |
| 
 | |
|   switch (TheLibFunc) {
 | |
|   case LibFunc::strlen:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::strchr:
 | |
|   case LibFunc::strrchr:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isIntegerTy())
 | |
|       return false;
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotThrow(F);
 | |
|     break;
 | |
|   case LibFunc::strtol:
 | |
|   case LibFunc::strtod:
 | |
|   case LibFunc::strtof:
 | |
|   case LibFunc::strtoul:
 | |
|   case LibFunc::strtoll:
 | |
|   case LibFunc::strtold:
 | |
|   case LibFunc::strtoull:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::strcpy:
 | |
|   case LibFunc::stpcpy:
 | |
|   case LibFunc::strcat:
 | |
|   case LibFunc::strncat:
 | |
|   case LibFunc::strncpy:
 | |
|   case LibFunc::stpncpy:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::strxfrm:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::strcmp: //0,1
 | |
|     case LibFunc::strspn: // 0,1
 | |
|     case LibFunc::strncmp: // 0,1
 | |
|     case LibFunc::strcspn: //0,1
 | |
|     case LibFunc::strcoll: //0,1
 | |
|     case LibFunc::strcasecmp:  // 0,1
 | |
|     case LibFunc::strncasecmp: // 
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::strstr:
 | |
|   case LibFunc::strpbrk:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::strtok:
 | |
|   case LibFunc::strtok_r:
 | |
|     if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::scanf:
 | |
|     if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::setbuf:
 | |
|   case LibFunc::setvbuf:
 | |
|     if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::strdup:
 | |
|   case LibFunc::strndup:
 | |
|     if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::stat:
 | |
|   case LibFunc::statvfs:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::sscanf:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::sprintf:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::snprintf:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(2)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 3);
 | |
|     setOnlyReadsMemory(F, 3);
 | |
|     break;
 | |
|   case LibFunc::setitimer:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(1)->isPointerTy() ||
 | |
|         !FTy->getParamType(2)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setDoesNotCapture(F, 3);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::system:
 | |
|     if (FTy->getNumParams() != 1 ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "system" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::malloc:
 | |
|     if (FTy->getNumParams() != 1 ||
 | |
|         !FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     break;
 | |
|   case LibFunc::memcmp:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::memchr:
 | |
|   case LibFunc::memrchr:
 | |
|     if (FTy->getNumParams() != 3)
 | |
|       return false;
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotThrow(F);
 | |
|     break;
 | |
|   case LibFunc::modf:
 | |
|   case LibFunc::modff:
 | |
|   case LibFunc::modfl:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::memcpy:
 | |
|   case LibFunc::memccpy:
 | |
|   case LibFunc::memmove:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::memalign:
 | |
|     if (!FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotAlias(F, 0);
 | |
|     break;
 | |
|   case LibFunc::mkdir:
 | |
|     if (FTy->getNumParams() == 0 ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::mktime:
 | |
|     if (FTy->getNumParams() == 0 ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::realloc:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::read:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "read" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::rewind:
 | |
|     if (FTy->getNumParams() < 1 ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::rmdir:
 | |
|   case LibFunc::remove:
 | |
|   case LibFunc::realpath:
 | |
|     if (FTy->getNumParams() < 1 ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::rename:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::readlink:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::write:
 | |
|     if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "write" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::bcopy:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::bcmp:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::bzero:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::calloc:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     break;
 | |
|   case LibFunc::chmod:
 | |
|   case LibFunc::chown:
 | |
|     if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::ctermid:
 | |
|   case LibFunc::clearerr:
 | |
|   case LibFunc::closedir:
 | |
|     if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::atoi:
 | |
|   case LibFunc::atol:
 | |
|   case LibFunc::atof:
 | |
|   case LibFunc::atoll:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::access:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::fopen:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::fdopen:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::feof:
 | |
|   case LibFunc::free:
 | |
|   case LibFunc::fseek:
 | |
|   case LibFunc::ftell:
 | |
|   case LibFunc::fgetc:
 | |
|   case LibFunc::fseeko:
 | |
|   case LibFunc::ftello:
 | |
|   case LibFunc::fileno:
 | |
|   case LibFunc::fflush:
 | |
|   case LibFunc::fclose:
 | |
|   case LibFunc::fsetpos:
 | |
|   case LibFunc::flockfile:
 | |
|   case LibFunc::funlockfile:
 | |
|   case LibFunc::ftrylockfile:
 | |
|     if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::ferror:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F);
 | |
|     break;
 | |
|   case LibFunc::fputc:
 | |
|   case LibFunc::fstat:
 | |
|   case LibFunc::frexp:
 | |
|   case LibFunc::frexpf:
 | |
|   case LibFunc::frexpl:
 | |
|   case LibFunc::fstatvfs:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::fgets:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(2)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 3);
 | |
|     break;
 | |
|   case LibFunc::fread:
 | |
|     if (FTy->getNumParams() != 4 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(3)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 4);
 | |
|     break;
 | |
|   case LibFunc::fwrite:
 | |
|     if (FTy->getNumParams() != 4 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(3)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 4);
 | |
|     break;
 | |
|   case LibFunc::fputs:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::fscanf:
 | |
|   case LibFunc::fprintf:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::fgetpos:
 | |
|     if (FTy->getNumParams() < 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::getc:
 | |
|   case LibFunc::getlogin_r:
 | |
|   case LibFunc::getc_unlocked:
 | |
|     if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::getenv:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setOnlyReadsMemory(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::gets:
 | |
|   case LibFunc::getchar:
 | |
|     setDoesNotThrow(F);
 | |
|     break;
 | |
|   case LibFunc::getitimer:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::getpwnam:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::ungetc:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::uname:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::unlink:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::unsetenv:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::utime:
 | |
|   case LibFunc::utimes:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::putc:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::puts:
 | |
|   case LibFunc::printf:
 | |
|   case LibFunc::perror:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::pread:
 | |
|     if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "pread" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::pwrite:
 | |
|     if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "pwrite" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::putchar:
 | |
|     setDoesNotThrow(F);
 | |
|     break;
 | |
|   case LibFunc::popen:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::pclose:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::vscanf:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::vsscanf:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(1)->isPointerTy() ||
 | |
|         !FTy->getParamType(2)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::vfscanf:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(1)->isPointerTy() ||
 | |
|         !FTy->getParamType(2)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::valloc:
 | |
|     if (!FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     break;
 | |
|   case LibFunc::vprintf:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::vfprintf:
 | |
|   case LibFunc::vsprintf:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::vsnprintf:
 | |
|     if (FTy->getNumParams() != 4 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(2)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 3);
 | |
|     setOnlyReadsMemory(F, 3);
 | |
|     break;
 | |
|   case LibFunc::open:
 | |
|     if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "open" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::opendir:
 | |
|     if (FTy->getNumParams() != 1 ||
 | |
|         !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::tmpfile:
 | |
|     if (!FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     break;
 | |
|   case LibFunc::times:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::htonl:
 | |
|   case LibFunc::htons:
 | |
|   case LibFunc::ntohl:
 | |
|   case LibFunc::ntohs:
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAccessMemory(F);
 | |
|     break;
 | |
|   case LibFunc::lstat:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::lchown:
 | |
|     if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::qsort:
 | |
|     if (FTy->getNumParams() != 4 || !FTy->getParamType(3)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; places call through function pointer.
 | |
|     setDoesNotCapture(F, 4);
 | |
|     break;
 | |
|   case LibFunc::dunder_strdup:
 | |
|   case LibFunc::dunder_strndup:
 | |
|     if (FTy->getNumParams() < 1 ||
 | |
|         !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::dunder_strtok_r:
 | |
|     if (FTy->getNumParams() != 3 ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::under_IO_getc:
 | |
|     if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::under_IO_putc:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::dunder_isoc99_scanf:
 | |
|     if (FTy->getNumParams() < 1 ||
 | |
|         !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::stat64:
 | |
|   case LibFunc::lstat64:
 | |
|   case LibFunc::statvfs64:
 | |
|     if (FTy->getNumParams() < 1 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::dunder_isoc99_sscanf:
 | |
|     if (FTy->getNumParams() < 1 ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::fopen64:
 | |
|     if (FTy->getNumParams() != 2 ||
 | |
|         !FTy->getReturnType()->isPointerTy() ||
 | |
|         !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     setOnlyReadsMemory(F, 2);
 | |
|     break;
 | |
|   case LibFunc::fseeko64:
 | |
|   case LibFunc::ftello64:
 | |
|     if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     break;
 | |
|   case LibFunc::tmpfile64:
 | |
|     if (!FTy->getReturnType()->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotAlias(F, 0);
 | |
|     break;
 | |
|   case LibFunc::fstat64:
 | |
|   case LibFunc::fstatvfs64:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   case LibFunc::open64:
 | |
|     if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
 | |
|       return false;
 | |
|     // May throw; "open" is a valid pthread cancellation point.
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setOnlyReadsMemory(F, 1);
 | |
|     break;
 | |
|   case LibFunc::gettimeofday:
 | |
|     if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
 | |
|         !FTy->getParamType(1)->isPointerTy())
 | |
|       return false;
 | |
|     // Currently some platforms have the restrict keyword on the arguments to
 | |
|     // gettimeofday. To be conservative, do not add noalias to gettimeofday's
 | |
|     // arguments.
 | |
|     setDoesNotThrow(F);
 | |
|     setDoesNotCapture(F, 1);
 | |
|     setDoesNotCapture(F, 2);
 | |
|     break;
 | |
|   default:
 | |
|     // Didn't mark any attributes.
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| /// annotateLibraryCalls - Adds attributes to well-known standard library
 | |
| /// call declarations.
 | |
| bool FunctionAttrs::annotateLibraryCalls(const CallGraphSCC &SCC) {
 | |
|   bool MadeChange = false;
 | |
| 
 | |
|   // Check each function in turn annotating well-known library function
 | |
|   // declarations with attributes.
 | |
|   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 | |
|     Function *F = (*I)->getFunction();
 | |
| 
 | |
|     if (F && F->isDeclaration())
 | |
|       MadeChange |= inferPrototypeAttributes(*F);
 | |
|   }
 | |
| 
 | |
|   return MadeChange;
 | |
| }
 | |
| 
 | |
| bool FunctionAttrs::runOnSCC(CallGraphSCC &SCC) {
 | |
|   AA = &getAnalysis<AliasAnalysis>();
 | |
|   TLI = &getAnalysis<TargetLibraryInfo>();
 | |
| 
 | |
|   bool Changed = annotateLibraryCalls(SCC);
 | |
|   Changed |= AddReadAttrs(SCC);
 | |
|   Changed |= AddArgumentAttrs(SCC);
 | |
|   Changed |= AddNoAliasAttrs(SCC);
 | |
|   return Changed;
 | |
| }
 |