mirror of
https://github.com/RPCS3/llvm.git
synced 2024-12-16 00:17:32 +00:00
move a bunch of predicates up into their own section
in this file, no other changes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52303 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
parent
e7275794d3
commit
defa1c8034
@ -32,110 +32,48 @@
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#include <algorithm>
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using namespace llvm;
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namespace {
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/// NoAA - This class implements the -no-aa pass, which always returns "I
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/// don't know" for alias queries. NoAA is unlike other alias analysis
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/// implementations, in that it does not chain to a previous analysis. As
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/// such it doesn't follow many of the rules that other alias analyses must.
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///
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struct VISIBILITY_HIDDEN NoAA : public ImmutablePass, public AliasAnalysis {
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static char ID; // Class identification, replacement for typeinfo
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NoAA() : ImmutablePass((intptr_t)&ID) {}
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explicit NoAA(intptr_t PID) : ImmutablePass(PID) { }
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//===----------------------------------------------------------------------===//
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// Useful predicates
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//===----------------------------------------------------------------------===//
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virtual void getAnalysisUsage(AnalysisUsage &AU) const {
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AU.addRequired<TargetData>();
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// Determine if an AllocationInst instruction escapes from the function it is
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// contained in. If it does not escape, there is no way for another function to
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// mod/ref it. We do this by looking at its uses and determining if the uses
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// can escape (recursively).
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static bool AddressMightEscape(const Value *V) {
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for (Value::use_const_iterator UI = V->use_begin(), E = V->use_end();
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UI != E; ++UI) {
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const Instruction *I = cast<Instruction>(*UI);
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switch (I->getOpcode()) {
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case Instruction::Load:
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break; //next use.
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case Instruction::Store:
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if (I->getOperand(0) == V)
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return true; // Escapes if the pointer is stored.
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break; // next use.
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case Instruction::GetElementPtr:
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if (AddressMightEscape(I))
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return true;
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break; // next use.
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case Instruction::BitCast:
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if (AddressMightEscape(I))
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return true;
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break; // next use
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case Instruction::Ret:
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// If returned, the address will escape to calling functions, but no
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// callees could modify it.
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break; // next use
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case Instruction::Call:
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// If the call is to a few known safe intrinsics, we know that it does
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// not escape
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if (!isa<MemIntrinsic>(I))
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return true;
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break; // next use
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default:
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return true;
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}
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virtual void initializePass() {
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TD = &getAnalysis<TargetData>();
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}
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virtual AliasResult alias(const Value *V1, unsigned V1Size,
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const Value *V2, unsigned V2Size) {
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return MayAlias;
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}
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virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
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std::vector<PointerAccessInfo> *Info) {
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return UnknownModRefBehavior;
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}
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virtual void getArgumentAccesses(Function *F, CallSite CS,
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std::vector<PointerAccessInfo> &Info) {
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assert(0 && "This method may not be called on this function!");
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}
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virtual void getMustAliases(Value *P, std::vector<Value*> &RetVals) { }
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virtual bool pointsToConstantMemory(const Value *P) { return false; }
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virtual ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size) {
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return ModRef;
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}
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virtual ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
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return ModRef;
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}
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virtual bool hasNoModRefInfoForCalls() const { return true; }
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virtual void deleteValue(Value *V) {}
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virtual void copyValue(Value *From, Value *To) {}
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};
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} // End of anonymous namespace
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// Register this pass...
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char NoAA::ID = 0;
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static RegisterPass<NoAA>
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U("no-aa", "No Alias Analysis (always returns 'may' alias)", true, true);
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// Declare that we implement the AliasAnalysis interface
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static RegisterAnalysisGroup<AliasAnalysis> V(U);
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ImmutablePass *llvm::createNoAAPass() { return new NoAA(); }
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namespace {
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/// BasicAliasAnalysis - This is the default alias analysis implementation.
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/// Because it doesn't chain to a previous alias analysis (like -no-aa), it
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/// derives from the NoAA class.
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struct VISIBILITY_HIDDEN BasicAliasAnalysis : public NoAA {
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static char ID; // Class identification, replacement for typeinfo
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BasicAliasAnalysis() : NoAA((intptr_t)&ID) { }
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AliasResult alias(const Value *V1, unsigned V1Size,
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const Value *V2, unsigned V2Size);
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ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
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ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
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return NoAA::getModRefInfo(CS1,CS2);
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}
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/// hasNoModRefInfoForCalls - We can provide mod/ref information against
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/// non-escaping allocations.
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virtual bool hasNoModRefInfoForCalls() const { return false; }
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/// pointsToConstantMemory - Chase pointers until we find a (constant
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/// global) or not.
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bool pointsToConstantMemory(const Value *P);
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private:
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// CheckGEPInstructions - Check two GEP instructions with known
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// must-aliasing base pointers. This checks to see if the index expressions
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// preclude the pointers from aliasing...
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AliasResult
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CheckGEPInstructions(const Type* BasePtr1Ty,
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Value **GEP1Ops, unsigned NumGEP1Ops, unsigned G1Size,
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const Type *BasePtr2Ty,
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Value **GEP2Ops, unsigned NumGEP2Ops, unsigned G2Size);
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};
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} // End of anonymous namespace
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// Register this pass...
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char BasicAliasAnalysis::ID = 0;
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static RegisterPass<BasicAliasAnalysis>
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X("basicaa", "Basic Alias Analysis (default AA impl)", false, true);
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// Declare that we implement the AliasAnalysis interface
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static RegisterAnalysisGroup<AliasAnalysis, true> Y(X);
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ImmutablePass *llvm::createBasicAliasAnalysisPass() {
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return new BasicAliasAnalysis();
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}
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return false;
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}
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/// getUnderlyingObject - This traverses the use chain to figure out what object
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@ -190,103 +128,6 @@ static const Value *GetGEPOperands(const Value *V,
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return V;
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}
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/// pointsToConstantMemory - Chase pointers until we find a (constant
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/// global) or not.
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bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) {
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if (const GlobalVariable *GV =
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dyn_cast<GlobalVariable>(getUnderlyingObject(P)))
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return GV->isConstant();
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return false;
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}
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// Determine if an AllocationInst instruction escapes from the function it is
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// contained in. If it does not escape, there is no way for another function to
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// mod/ref it. We do this by looking at its uses and determining if the uses
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// can escape (recursively).
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static bool AddressMightEscape(const Value *V) {
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for (Value::use_const_iterator UI = V->use_begin(), E = V->use_end();
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UI != E; ++UI) {
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const Instruction *I = cast<Instruction>(*UI);
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switch (I->getOpcode()) {
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case Instruction::Load:
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break; //next use.
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case Instruction::Store:
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if (I->getOperand(0) == V)
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return true; // Escapes if the pointer is stored.
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break; // next use.
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case Instruction::GetElementPtr:
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if (AddressMightEscape(I))
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return true;
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break; // next use.
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case Instruction::BitCast:
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if (AddressMightEscape(I))
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return true;
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break; // next use
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case Instruction::Ret:
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// If returned, the address will escape to calling functions, but no
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// callees could modify it.
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break; // next use
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case Instruction::Call:
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// If the call is to a few known safe intrinsics, we know that it does
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// not escape
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if (!isa<MemIntrinsic>(I))
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return true;
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break; // next use
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default:
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return true;
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}
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}
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return false;
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}
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// getModRefInfo - Check to see if the specified callsite can clobber the
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// specified memory object. Since we only look at local properties of this
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// function, we really can't say much about this query. We do, however, use
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// simple "address taken" analysis on local objects.
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//
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AliasAnalysis::ModRefResult
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BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
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if (!isa<Constant>(P)) {
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const Value *Object = getUnderlyingObject(P);
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// If this is a tail call and P points to a stack location, we know that
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// the tail call cannot access or modify the local stack.
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// We cannot exclude byval arguments here; these belong to the caller of
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// the current function not to the current function, and a tail callee
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// may reference them.
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if (isa<AllocaInst>(Object))
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if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction()))
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if (CI->isTailCall())
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return NoModRef;
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// Allocations and byval arguments are "new" objects.
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if (isa<AllocationInst>(Object) || isa<Argument>(Object)) {
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// Okay, the pointer is to a stack allocated (or effectively so, for
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// for noalias parameters) object. If the address of this object doesn't
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// escape from this function body to a callee, then we know that no
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// callees can mod/ref it unless they are actually passed it.
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if (isa<AllocationInst>(Object) ||
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cast<Argument>(Object)->hasByValAttr() ||
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cast<Argument>(Object)->hasNoAliasAttr())
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if (!AddressMightEscape(Object)) {
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bool passedAsArg = false;
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for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
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CI != CE; ++CI)
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if (isa<PointerType>((*CI)->getType()) &&
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(getUnderlyingObject(*CI) == P ||
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alias(cast<Value>(CI), ~0U, P, ~0U) != NoAlias))
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passedAsArg = true;
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if (!passedAsArg)
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return NoModRef;
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}
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}
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}
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// The AliasAnalysis base class has some smarts, lets use them.
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return AliasAnalysis::getModRefInfo(CS, P, Size);
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}
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/// isIdentifiedObject - Return true if this pointer refers to a distinct and
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/// identifiable object. This returns true for:
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/// Global Variables and Functions
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@ -354,6 +195,179 @@ static bool isObjectSmallerThan(const Value *V, unsigned Size,
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return false;
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}
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//===----------------------------------------------------------------------===//
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// NoAA Pass
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//===----------------------------------------------------------------------===//
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namespace {
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/// NoAA - This class implements the -no-aa pass, which always returns "I
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/// don't know" for alias queries. NoAA is unlike other alias analysis
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/// implementations, in that it does not chain to a previous analysis. As
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/// such it doesn't follow many of the rules that other alias analyses must.
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///
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struct VISIBILITY_HIDDEN NoAA : public ImmutablePass, public AliasAnalysis {
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static char ID; // Class identification, replacement for typeinfo
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NoAA() : ImmutablePass((intptr_t)&ID) {}
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explicit NoAA(intptr_t PID) : ImmutablePass(PID) { }
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virtual void getAnalysisUsage(AnalysisUsage &AU) const {
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AU.addRequired<TargetData>();
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}
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virtual void initializePass() {
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TD = &getAnalysis<TargetData>();
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}
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virtual AliasResult alias(const Value *V1, unsigned V1Size,
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const Value *V2, unsigned V2Size) {
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return MayAlias;
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}
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virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
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std::vector<PointerAccessInfo> *Info) {
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return UnknownModRefBehavior;
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}
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virtual void getArgumentAccesses(Function *F, CallSite CS,
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std::vector<PointerAccessInfo> &Info) {
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assert(0 && "This method may not be called on this function!");
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}
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virtual void getMustAliases(Value *P, std::vector<Value*> &RetVals) { }
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virtual bool pointsToConstantMemory(const Value *P) { return false; }
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virtual ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size) {
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return ModRef;
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}
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virtual ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
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return ModRef;
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}
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virtual bool hasNoModRefInfoForCalls() const { return true; }
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virtual void deleteValue(Value *V) {}
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virtual void copyValue(Value *From, Value *To) {}
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};
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} // End of anonymous namespace
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// Register this pass...
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char NoAA::ID = 0;
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static RegisterPass<NoAA>
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U("no-aa", "No Alias Analysis (always returns 'may' alias)", true, true);
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// Declare that we implement the AliasAnalysis interface
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static RegisterAnalysisGroup<AliasAnalysis> V(U);
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ImmutablePass *llvm::createNoAAPass() { return new NoAA(); }
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//===----------------------------------------------------------------------===//
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// BasicAA Pass
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//===----------------------------------------------------------------------===//
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namespace {
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/// BasicAliasAnalysis - This is the default alias analysis implementation.
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/// Because it doesn't chain to a previous alias analysis (like -no-aa), it
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/// derives from the NoAA class.
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struct VISIBILITY_HIDDEN BasicAliasAnalysis : public NoAA {
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static char ID; // Class identification, replacement for typeinfo
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BasicAliasAnalysis() : NoAA((intptr_t)&ID) { }
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AliasResult alias(const Value *V1, unsigned V1Size,
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const Value *V2, unsigned V2Size);
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ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
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ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
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return NoAA::getModRefInfo(CS1,CS2);
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}
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/// hasNoModRefInfoForCalls - We can provide mod/ref information against
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/// non-escaping allocations.
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virtual bool hasNoModRefInfoForCalls() const { return false; }
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/// pointsToConstantMemory - Chase pointers until we find a (constant
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/// global) or not.
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bool pointsToConstantMemory(const Value *P);
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private:
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// CheckGEPInstructions - Check two GEP instructions with known
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// must-aliasing base pointers. This checks to see if the index expressions
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// preclude the pointers from aliasing...
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AliasResult
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CheckGEPInstructions(const Type* BasePtr1Ty,
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Value **GEP1Ops, unsigned NumGEP1Ops, unsigned G1Size,
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const Type *BasePtr2Ty,
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Value **GEP2Ops, unsigned NumGEP2Ops, unsigned G2Size);
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};
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} // End of anonymous namespace
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// Register this pass...
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char BasicAliasAnalysis::ID = 0;
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static RegisterPass<BasicAliasAnalysis>
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X("basicaa", "Basic Alias Analysis (default AA impl)", false, true);
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// Declare that we implement the AliasAnalysis interface
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static RegisterAnalysisGroup<AliasAnalysis, true> Y(X);
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ImmutablePass *llvm::createBasicAliasAnalysisPass() {
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return new BasicAliasAnalysis();
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}
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/// pointsToConstantMemory - Chase pointers until we find a (constant
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/// global) or not.
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bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) {
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if (const GlobalVariable *GV =
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dyn_cast<GlobalVariable>(getUnderlyingObject(P)))
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return GV->isConstant();
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return false;
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}
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// getModRefInfo - Check to see if the specified callsite can clobber the
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// specified memory object. Since we only look at local properties of this
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// function, we really can't say much about this query. We do, however, use
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// simple "address taken" analysis on local objects.
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//
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AliasAnalysis::ModRefResult
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BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
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if (!isa<Constant>(P)) {
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const Value *Object = getUnderlyingObject(P);
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// If this is a tail call and P points to a stack location, we know that
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// the tail call cannot access or modify the local stack.
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// We cannot exclude byval arguments here; these belong to the caller of
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// the current function not to the current function, and a tail callee
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// may reference them.
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if (isa<AllocaInst>(Object))
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if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction()))
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if (CI->isTailCall())
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return NoModRef;
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// Allocations and byval arguments are "new" objects.
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if (isa<AllocationInst>(Object) || isa<Argument>(Object)) {
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// Okay, the pointer is to a stack allocated (or effectively so, for
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// for noalias parameters) object. If the address of this object doesn't
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// escape from this function body to a callee, then we know that no
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// callees can mod/ref it unless they are actually passed it.
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if (isa<AllocationInst>(Object) ||
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cast<Argument>(Object)->hasByValAttr() ||
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cast<Argument>(Object)->hasNoAliasAttr())
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if (!AddressMightEscape(Object)) {
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bool passedAsArg = false;
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for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
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CI != CE; ++CI)
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if (isa<PointerType>((*CI)->getType()) &&
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(getUnderlyingObject(*CI) == P ||
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alias(cast<Value>(CI), ~0U, P, ~0U) != NoAlias))
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passedAsArg = true;
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if (!passedAsArg)
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return NoModRef;
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}
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}
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}
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// The AliasAnalysis base class has some smarts, lets use them.
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return AliasAnalysis::getModRefInfo(CS, P, Size);
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}
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// alias - Provide a bunch of ad-hoc rules to disambiguate in common cases, such
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// as array references. Note that this function is heavily tail recursive.
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// Hopefully we have a smart C++ compiler. :)
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