#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
+#include "llvm/ParameterAttributes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/BitVector.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/ManagedStatic.h"
/// such it doesn't follow many of the rules that other alias analyses must.
///
struct VISIBILITY_HIDDEN NoAA : public ImmutablePass, public AliasAnalysis {
+ static char ID; // Class identification, replacement for typeinfo
+ NoAA() : ImmutablePass((intptr_t)&ID) {}
+ explicit NoAA(intptr_t PID) : ImmutablePass(PID) { }
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetData>();
}
};
// Register this pass...
+ char NoAA::ID = 0;
RegisterPass<NoAA>
U("no-aa", "No Alias Analysis (always returns 'may' alias)");
/// Because it doesn't chain to a previous alias analysis (like -no-aa), it
/// derives from the NoAA class.
struct VISIBILITY_HIDDEN BasicAliasAnalysis : public NoAA {
+ static char ID; // Class identification, replacement for typeinfo
+ BasicAliasAnalysis() : NoAA((intptr_t)&ID) { }
AliasResult alias(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size);
bool pointsToConstantMemory(const Value *P);
virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
-
std::vector<PointerAccessInfo> *Info);
+ std::vector<PointerAccessInfo> *Info);
private:
// CheckGEPInstructions - Check two GEP instructions with known
// must-aliasing base pointers. This checks to see if the index expressions
// preclude the pointers from aliasing...
AliasResult
- CheckGEPInstructions(const Type* BasePtr1Ty, std::vector<Value*> &GEP1Ops,
- unsigned G1Size,
- const Type *BasePtr2Ty, std::vector<Value*> &GEP2Ops,
- unsigned G2Size);
+ CheckGEPInstructions(const Type* BasePtr1Ty,
+ Value **GEP1Ops, unsigned NumGEP1Ops, unsigned G1Size,
+ const Type *BasePtr2Ty,
+ Value **GEP2Ops, unsigned NumGEP2Ops, unsigned G2Size);
};
// Register this pass...
+ char BasicAliasAnalysis::ID = 0;
RegisterPass<BasicAliasAnalysis>
X("basicaa", "Basic Alias Analysis (default AA impl)");
return new BasicAliasAnalysis();
}
-// hasUniqueAddress - Return true if the specified value points to something
-// with a unique, discernable, address.
-static inline bool hasUniqueAddress(const Value *V) {
- return isa<GlobalValue>(V) || isa<AllocationInst>(V);
-}
-
// getUnderlyingObject - This traverses the use chain to figure out what object
// the specified value points to. If the value points to, or is derived from, a
// unique object or an argument, return it.
static const Value *getUnderlyingObject(const Value *V) {
if (!isa<PointerType>(V->getType())) return 0;
- // If we are at some type of object... return it.
- if (hasUniqueAddress(V) || isa<Argument>(V)) return V;
+ // If we are at some type of object, return it. GlobalValues and Allocations
+ // have unique addresses.
+ if (isa<GlobalValue>(V) || isa<AllocationInst>(V) || isa<Argument>(V))
+ return V;
// Traverse through different addressing mechanisms...
if (const Instruction *I = dyn_cast<Instruction>(V)) {
- if (isa<CastInst>(I) || isa<GetElementPtrInst>(I))
+ if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I))
return getUnderlyingObject(I->getOperand(0));
} else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
- if (CE->getOpcode() == Instruction::Cast ||
+ if (CE->getOpcode() == Instruction::BitCast ||
CE->getOpcode() == Instruction::GetElementPtr)
return getUnderlyingObject(CE->getOperand(0));
- } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
- return GV;
}
return 0;
}
return 0;
}
-static const Value *GetGEPOperands(const Value *V, std::vector<Value*> &GEPOps){
+static const Value *GetGEPOperands(const Value *V,
+ SmallVector<Value*, 16> &GEPOps){
assert(GEPOps.empty() && "Expect empty list to populate!");
GEPOps.insert(GEPOps.end(), cast<User>(V)->op_begin()+1,
cast<User>(V)->op_end());
return false;
}
+// Determine if an AllocationInst instruction escapes from the function it is
+// contained in. If it does not escape, there is no way for another function to
+// mod/ref it. We do this by looking at its uses and determining if the uses
+// can escape (recursively).
static bool AddressMightEscape(const Value *V) {
for (Value::use_const_iterator UI = V->use_begin(), E = V->use_end();
UI != E; ++UI) {
const Instruction *I = cast<Instruction>(*UI);
switch (I->getOpcode()) {
- case Instruction::Load: break;
+ case Instruction::Load:
+ break; //next use.
case Instruction::Store:
if (I->getOperand(0) == V)
return true; // Escapes if the pointer is stored.
- break;
+ break; // next use.
case Instruction::GetElementPtr:
- if (AddressMightEscape(I)) return true;
- break;
- case Instruction::Cast:
+ if (AddressMightEscape(I))
+ return true;
+ break; // next use.
+ case Instruction::BitCast:
if (!isa<PointerType>(I->getType()))
return true;
- if (AddressMightEscape(I)) return true;
- break;
+ if (AddressMightEscape(I))
+ return true;
+ break; // next use
case Instruction::Ret:
// If returned, the address will escape to calling functions, but no
// callees could modify it.
- break;
+ break; // next use
default:
return true;
}
return AliasAnalysis::getModRefInfo(CS, P, Size);
}
+static bool isNoAliasArgument(const Argument *Arg) {
+ const Function *Func = Arg->getParent();
+ const ParamAttrsList *Attr = Func->getFunctionType()->getParamAttrs();
+ if (Attr) {
+ unsigned Idx = 1;
+ for (Function::const_arg_iterator I = Func->arg_begin(),
+ E = Func->arg_end(); I != E; ++I, ++Idx) {
+ if (&(*I) == Arg &&
+ Attr->paramHasAttr(Idx, ParamAttr::NoAlias))
+ return true;
+ }
+ }
+ return false;
+}
+
// alias - Provide a bunch of ad-hoc rules to disambiguate in common cases, such
// as array references. Note that this function is heavily tail recursive.
// Hopefully we have a smart C++ compiler. :)
const Value *V2, unsigned V2Size) {
// Strip off any constant expression casts if they exist
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V1))
- if (CE->getOpcode() == Instruction::Cast &&
- isa<PointerType>(CE->getOperand(0)->getType()))
+ if (CE->isCast() && isa<PointerType>(CE->getOperand(0)->getType()))
V1 = CE->getOperand(0);
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V2))
- if (CE->getOpcode() == Instruction::Cast &&
- isa<PointerType>(CE->getOperand(0)->getType()))
+ if (CE->isCast() && isa<PointerType>(CE->getOperand(0)->getType()))
V2 = CE->getOperand(0);
// Are we checking for alias of the same value?
if (V1 == V2) return MustAlias;
if ((!isa<PointerType>(V1->getType()) || !isa<PointerType>(V2->getType())) &&
- V1->getType() != Type::LongTy && V2->getType() != Type::LongTy)
+ V1->getType() != Type::Int64Ty && V2->getType() != Type::Int64Ty)
return NoAlias; // Scalars cannot alias each other
// Strip off cast instructions...
- if (const Instruction *I = dyn_cast<CastInst>(V1))
- if (isa<PointerType>(I->getOperand(0)->getType()))
- return alias(I->getOperand(0), V1Size, V2, V2Size);
- if (const Instruction *I = dyn_cast<CastInst>(V2))
- if (isa<PointerType>(I->getOperand(0)->getType()))
- return alias(V1, V1Size, I->getOperand(0), V2Size);
+ if (const BitCastInst *I = dyn_cast<BitCastInst>(V1))
+ return alias(I->getOperand(0), V1Size, V2, V2Size);
+ if (const BitCastInst *I = dyn_cast<BitCastInst>(V2))
+ return alias(V1, V1Size, I->getOperand(0), V2Size);
// Figure out what objects these things are pointing to if we can...
const Value *O1 = getUnderlyingObject(V1);
// Pointing at a discernible object?
if (O1) {
if (O2) {
- if (
isa<Argument>(O1)) {
+ if (
const Argument *O1Arg = dyn_cast<Argument>(O1)) {
// Incoming argument cannot alias locally allocated object!
if (isa<AllocationInst>(O2)) return NoAlias;
+
+ // If they are two different objects, and one is a noalias argument
+ // then they do not alias.
+ if (O1 != O2 && isNoAliasArgument(O1Arg))
+ return NoAlias;
+
// Otherwise, nothing is known...
- } else if (isa<Argument>(O2)) {
+ }
+
+ if (const Argument *O2Arg = dyn_cast<Argument>(O2)) {
// Incoming argument cannot alias locally allocated object!
if (isa<AllocationInst>(O1)) return NoAlias;
+
+ // If they are two different objects, and one is a noalias argument
+ // then they do not alias.
+ if (O1 != O2 && isNoAliasArgument(O2Arg))
+ return NoAlias;
+
// Otherwise, nothing is known...
} else if (O1 != O2) {
// If they are two different objects, we know that we have no alias...
Constant::getNullValue(cast<User>(BasePtr2)->getOperand(1)->getType()));
// Do the base pointers alias?
- AliasResult BaseAlias = alias(BasePtr1, V1Size, BasePtr2, V2Size);
+ AliasResult BaseAlias = alias(BasePtr1, ~0U, BasePtr2, ~0U);
if (BaseAlias == NoAlias) return NoAlias;
if (BaseAlias == MustAlias) {
// If the base pointers alias each other exactly, check to see if we can
// non-aliasing.
// Collect all of the chained GEP operands together into one simple place
- std::vector<Value*> GEP1Ops, GEP2Ops;
+ SmallVector<Value*, 16> GEP1Ops, GEP2Ops;
BasePtr1 = GetGEPOperands(V1, GEP1Ops);
BasePtr2 = GetGEPOperands(V2, GEP2Ops);
// do the comparison.
if (BasePtr1 == BasePtr2) {
AliasResult GAlias =
- CheckGEPInstructions(BasePtr1->getType(), GEP1Ops, V1Size,
- BasePtr2->getType(), GEP2Ops, V2Size);
+ CheckGEPInstructions(BasePtr1->getType(),
+ &GEP1Ops[0], GEP1Ops.size(), V1Size,
+ BasePtr2->getType(),
+ &GEP2Ops[0], GEP2Ops.size(), V2Size);
if (GAlias != MayAlias)
return GAlias;
}
}
if (V1Size != ~0U && V2Size != ~0U)
- if (const User *GEP = isGEP(V1)) {
- std::vector<Value*> GEPOperands;
+ if (isGEP(V1)) {
+ SmallVector<Value*, 16> GEPOperands;
const Value *BasePtr = GetGEPOperands(V1, GEPOperands);
AliasResult R = alias(BasePtr, V1Size, V2, V2Size);
GEPOperands[i] =
Constant::getNullValue(GEPOperands[i]->getType());
int64_t Offset =
- getTargetData().getIndexedOffset(BasePtr->getType(), GEPOperands);
+ getTargetData().getIndexedOffset(BasePtr->getType(),
+ &GEPOperands[0],
+ GEPOperands.size());
if (Offset >= (int64_t)V2Size || Offset <= -(int64_t)V1Size)
return NoAlias;
return MayAlias;
}
-static bool ValuesEqual(Value *V1, Value *V2) {
+// This function is used to determin if the indices of two GEP instructions are
+// equal. V1 and V2 are the indices.
+static bool IndexOperandsEqual(Value *V1, Value *V2) {
if (V1->getType() == V2->getType())
return V1 == V2;
if (Constant *C1 = dyn_cast<Constant>(V1))
if (Constant *C2 = dyn_cast<Constant>(V2)) {
- // Sign extend the constants to long types.
- C1 = ConstantExpr::getSignExtend(C1, Type::LongTy);
- C2 = ConstantExpr::getSignExtend(C2, Type::LongTy);
+ // Sign extend the constants to long types, if necessary
+ if (C1->getType() != Type::Int64Ty)
+ C1 = ConstantExpr::getSExt(C1, Type::Int64Ty);
+ if (C2->getType() != Type::Int64Ty)
+ C2 = ConstantExpr::getSExt(C2, Type::Int64Ty);
return C1 == C2;
}
return false;
/// CheckGEPInstructions - Check two GEP instructions with known must-aliasing
/// base pointers. This checks to see if the index expressions preclude the
/// pointers from aliasing...
-AliasAnalysis::AliasResult BasicAliasAnalysis::
-CheckGEPInstructions(const Type* BasePtr1Ty, std::vector<Value*> &GEP1Ops,
- unsigned G1S,
- const Type *BasePtr2Ty, std::vector<Value*> &GEP2Ops,
- unsigned G2S) {
+AliasAnalysis::AliasResult
+BasicAliasAnalysis::CheckGEPInstructions(
+ const Type* BasePtr1Ty, Value **GEP1Ops, unsigned NumGEP1Ops, unsigned G1S,
+ const Type *BasePtr2Ty, Value **GEP2Ops, unsigned NumGEP2Ops, unsigned G2S) {
// We currently can't handle the case when the base pointers have different
// primitive types. Since this is uncommon anyway, we are happy being
// extremely conservative.
// Find the (possibly empty) initial sequence of equal values... which are not
// necessarily constants.
- unsigned NumGEP1Operands = GEP1Ops.size(), NumGEP2Operands = GEP2Ops.size();
+ unsigned NumGEP1Operands = NumGEP1Ops, NumGEP2Operands = NumGEP2Ops;
unsigned MinOperands = std::min(NumGEP1Operands, NumGEP2Operands);
unsigned MaxOperands = std::max(NumGEP1Operands, NumGEP2Operands);
unsigned UnequalOper = 0;
while (UnequalOper != MinOperands &&
- ValuesEqual(GEP1Ops[UnequalOper], GEP2Ops[UnequalOper])) {
+ IndexOperandsEqual(GEP1Ops[UnequalOper], GEP2Ops[UnequalOper])) {
// Advance through the type as we go...
++UnequalOper;
if (const CompositeType *CT = dyn_cast<CompositeType>(BasePtr1Ty))
// getelementptrs, check to see if the tail of the leftover one is all zeros.
// If so, return mustalias.
if (UnequalOper == MinOperands) {
- if (GEP1Ops.size() < GEP2Ops.size()) std::swap(GEP1Ops, GEP2Ops);
+ if (NumGEP1Ops < NumGEP2Ops) {
+ std::swap(GEP1Ops, GEP2Ops);
+ std::swap(NumGEP1Ops, NumGEP2Ops);
+ }
bool AllAreZeros = true;
for (unsigned i = UnequalOper; i != MaxOperands; ++i)
if (Constant *G2OC = dyn_cast<ConstantInt>(const_cast<Value*>(G2Oper))){
if (G1OC->getType() != G2OC->getType()) {
// Sign extend both operands to long.
- G1OC = ConstantExpr::getSignExtend(G1OC, Type::LongTy);
- G2OC = ConstantExpr::getSignExtend(G2OC, Type::LongTy);
+ if (G1OC->getType() != Type::Int64Ty)
+ G1OC = ConstantExpr::getSExt(G1OC, Type::Int64Ty);
+ if (G2OC->getType() != Type::Int64Ty)
+ G2OC = ConstantExpr::getSExt(G2OC, Type::Int64Ty);
GEP1Ops[FirstConstantOper] = G1OC;
GEP2Ops[FirstConstantOper] = G2OC;
}
if (G1OC != G2OC) {
- // Handle the "be careful" case above: if this is an array
+ // Handle the "be careful" case above: if this is an array/vector
// subscript, scan for a subsequent variable array index.
- if (isa<ArrayType>(BasePtr1Ty)) {
- const Type *NextTy =cast<ArrayType>(BasePtr1Ty)->getElementType();
+ if (isa<SequentialType>(BasePtr1Ty)) {
+ const Type *NextTy =
+ cast<SequentialType>(BasePtr1Ty)->getElementType();
bool isBadCase = false;
for (unsigned Idx = FirstConstantOper+1;
- Idx != MinOperands && isa<ArrayType>(NextTy); ++Idx) {
+ Idx != MinOperands && isa<SequentialType>(NextTy); ++Idx) {
const Value *V1 = GEP1Ops[Idx], *V2 = GEP2Ops[Idx];
if (!isa<Constant>(V1) || !isa<Constant>(V2)) {
isBadCase = true;
break;
}
- NextTy = cast<ArrayType>(NextTy)->getElementType();
+ NextTy = cast<SequentialType>(NextTy)->getElementType();
}
if (isBadCase) G1OC = 0;
// Make sure they are comparable (ie, not constant expressions), and
// make sure the GEP with the smaller leading constant is GEP1.
if (G1OC) {
- Constant *Compare = ConstantExpr::getSetGT(G1OC, G2OC);
- if (ConstantBool *CV = dyn_cast<ConstantBool>(Compare)) {
- if (CV->getValue()) // If they are comparable and G2 > G1
+ Constant *Compare = ConstantExpr::getICmp(ICmpInst::ICMP_SGT,
+ G1OC, G2OC);
+ if (ConstantInt *CV = dyn_cast<ConstantInt>(Compare)) {
+ if (CV->getZExtValue()) { // If they are comparable and G2 > G1
std::swap(GEP1Ops, GEP2Ops); // Make GEP1 < GEP2
+ std::swap(NumGEP1Ops, NumGEP2Ops);
+ }
break;
}
}
// case, there may still be hope. Check this now.
if (FirstConstantOper == MinOperands) {
// Make GEP1Ops be the longer one if there is a longer one.
- if (GEP1Ops.size() < GEP2Ops.size())
+ if (NumGEP1Ops < NumGEP2Ops) {
std::swap(GEP1Ops, GEP2Ops);
+ std::swap(NumGEP1Ops, NumGEP2Ops);
+ }
// Is there anything to check?
- if (GEP1Ops.size() > MinOperands) {
+ if (NumGEP1Ops > MinOperands) {
for (unsigned i = FirstConstantOper; i != MaxOperands; ++i)
- if (isa<ConstantInt>(GEP1Ops[i]) &&
- !cast<Constant>(GEP1Ops[i])->isNullValue()) {
+ if (isa<ConstantInt>(GEP1Ops[i]) &&
+ !cast<ConstantInt>(GEP1Ops[i])->isZero()) {
// Yup, there's a constant in the tail. Set all variables to
// constants in the GEP instruction to make it suiteable for
// TargetData::getIndexedOffset.
// Okay, now get the offset. This is the relative offset for the full
// instruction.
const TargetData &TD = getTargetData();
- int64_t Offset1 = TD.getIndexedOffset(GEPPointerTy, GEP1Ops);
+ int64_t Offset1 = TD.getIndexedOffset(GEPPointerTy, GEP1Ops,
+ NumGEP1Ops);
- // Now crop off any constants from the end...
- GEP1Ops.resize(MinOperands);
- int64_t Offset2 = TD.getIndexedOffset(GEPPointerTy, GEP1Ops);
+ // Now check without any constants at the end.
+ int64_t Offset2 = TD.getIndexedOffset(GEPPointerTy, GEP1Ops,
+ MinOperands);
// If the tail provided a bit enough offset, return noalias!
if ((uint64_t)(Offset2-Offset1) >= SizeMax)
const Type *ZeroIdxTy = GEPPointerTy;
for (unsigned i = 0; i != FirstConstantOper; ++i) {
if (!isa<StructType>(ZeroIdxTy))
- GEP1Ops[i] = GEP2Ops[i] = Constant::getNullValue(Type::UIntTy);
+ GEP1Ops[i] = GEP2Ops[i] = Constant::getNullValue(Type::Int32Ty);
if (const CompositeType *CT = dyn_cast<CompositeType>(ZeroIdxTy))
ZeroIdxTy = CT->getTypeAtIndex(GEP1Ops[i]);
// Loop over the rest of the operands...
for (unsigned i = FirstConstantOper+1; i != MaxOperands; ++i) {
- const Value *Op1 = i < GEP1Ops.size() ? GEP1Ops[i] : 0;
- const Value *Op2 = i < GEP2Ops.size() ? GEP2Ops[i] : 0;
+ const Value *Op1 = i < NumGEP1Ops ? GEP1Ops[i] : 0;
+ const Value *Op2 = i < NumGEP2Ops ? GEP2Ops[i] : 0;
// If they are equal, use a zero index...
if (Op1 == Op2 && BasePtr1Ty == BasePtr2Ty) {
if (!isa<ConstantInt>(Op1))
if (Op1) {
if (const ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
// If this is an array index, make sure the array element is in range.
- if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
- if (Op1C->getRawValue() >= AT->getNumElements())
+ if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty)) {
+ if (Op1C->getZExtValue() >= AT->getNumElements())
return MayAlias; // Be conservative with out-of-range accesses
-
+ } else if (const VectorType *PT = dyn_cast<VectorType>(BasePtr1Ty)) {
+ if (Op1C->getZExtValue() >= PT->getNumElements())
+ return MayAlias; // Be conservative with out-of-range accesses
+ }
+
} else {
// GEP1 is known to produce a value less than GEP2. To be
// conservatively correct, we must assume the largest possible
// value possible.
//
if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
- GEP1Ops[i] = ConstantSInt::get(Type::LongTy,AT->getNumElements()-1);
+ GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,AT->getNumElements()-1);
+ else if (const VectorType *PT = dyn_cast<VectorType>(BasePtr1Ty))
+ GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,PT->getNumElements()-1);
+
}
}
if (Op2) {
if (const ConstantInt *Op2C = dyn_cast<ConstantInt>(Op2)) {
// If this is an array index, make sure the array element is in range.
- if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
- if (Op2C->getRawValue() >= AT->getNumElements())
+ if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty)) {
+ if (Op2C->getZExtValue() >= AT->getNumElements())
+ return MayAlias; // Be conservative with out-of-range accesses
+ } else if (const VectorType *PT = dyn_cast<VectorType>(BasePtr1Ty)) {
+ if (Op2C->getZExtValue() >= PT->getNumElements())
return MayAlias; // Be conservative with out-of-range accesses
+ }
} else { // Conservatively assume the minimum value for this index
GEP2Ops[i] = Constant::getNullValue(Op2->getType());
}
}
if (GEPPointerTy->getElementType()->isSized()) {
- int64_t Offset1 = getTargetData().getIndexedOffset(GEPPointerTy, GEP1Ops);
- int64_t Offset2 = getTargetData().getIndexedOffset(GEPPointerTy, GEP2Ops);
+ int64_t Offset1 =
+ getTargetData().getIndexedOffset(GEPPointerTy, GEP1Ops, NumGEP1Ops);
+ int64_t Offset2 =
+ getTargetData().getIndexedOffset(GEPPointerTy, GEP2Ops, NumGEP2Ops);
assert(Offset1<Offset2 && "There is at least one different constant here!");
if ((uint64_t)(Offset2-Offset1) >= SizeMax) {
- //std::cerr << "Determined that these two GEP's don't alias ["
- // << SizeMax << " bytes]: \n" << *GEP1 << *GEP2;
+ //cerr << "Determined that these two GEP's don't alias ["
+ // << SizeMax << " bytes]: \n" << *GEP1 << *GEP2;
return NoAlias;
}
}
}
namespace {
- struct StringCompare {
+ struct VISIBILITY_HIDDEN StringCompare {
bool operator()(const char *LHS, const char *RHS) {
return strcmp(LHS, RHS) < 0;
}
static ManagedStatic<std::vector<const char*> > NoMemoryTable;
static ManagedStatic<std::vector<const char*> > OnlyReadsMemoryTable;
+static ManagedStatic<BitVector> NoMemoryIntrinsics;
+static ManagedStatic<BitVector> OnlyReadsMemoryIntrinsics;
+
AliasAnalysis::ModRefBehavior
BasicAliasAnalysis::getModRefBehavior(Function *F, CallSite CS,
std::vector<PointerAccessInfo> *Info) {
- if (!F->isExternal()) return UnknownModRefBehavior;
+ if (!F->isDeclaration()) return UnknownModRefBehavior;
static bool Initialized = false;
if (!Initialized) {
OnlyReadsMemoryFns,
OnlyReadsMemoryFns+
sizeof(OnlyReadsMemoryFns)/sizeof(OnlyReadsMemoryFns[0]));
-#define GET_MODREF_BEHAVIOR
-#include "llvm/Intrinsics.gen"
-#undef GET_MODREF_BEHAVIOR
-
+
// Sort the table the first time through.
std::sort(NoMemoryTable->begin(), NoMemoryTable->end(), StringCompare());
std::sort(OnlyReadsMemoryTable->begin(), OnlyReadsMemoryTable->end(),
StringCompare());
+
+ NoMemoryIntrinsics->resize(Intrinsic::num_intrinsics);
+ OnlyReadsMemoryIntrinsics->resize(Intrinsic::num_intrinsics);
+#define GET_MODREF_BEHAVIOR
+#include "llvm/Intrinsics.gen"
+#undef GET_MODREF_BEHAVIOR
+
Initialized = true;
}
+ // If this is an intrinsic, we can use lookup tables
+ if (unsigned id = F->getIntrinsicID()) {
+ if (NoMemoryIntrinsics->test(id))
+ return DoesNotAccessMemory;
+ if (OnlyReadsMemoryIntrinsics->test(id))
+ return OnlyReadsMemory;
+
+ return UnknownModRefBehavior;
+ }
+
+ ValueName *Name = F->getValueName();
+ unsigned NameLen = Name->getKeyLength();
+ const char *NamePtr = Name->getKeyData();
+
+ // If there is an embedded nul character in the function name, we can never
+ // match it.
+ if (strlen(NamePtr) != NameLen)
+ return UnknownModRefBehavior;
+
std::vector<const char*>::iterator Ptr =
std::lower_bound(NoMemoryTable->begin(), NoMemoryTable->end(),
- F->getName().c_str(), StringCompare());
- if (Ptr != NoMemoryTable->end() && *Ptr == F->getName())
+ NamePtr, StringCompare());
+ if (Ptr != NoMemoryTable->end() && strcmp(*Ptr, NamePtr) == 0)
return DoesNotAccessMemory;
Ptr = std::lower_bound(OnlyReadsMemoryTable->begin(),
OnlyReadsMemoryTable->end(),
- F->getName().c_str(), StringCompare());
- if (Ptr != OnlyReadsMemoryTable->end() && *Ptr == F->getName())
+ NamePtr, StringCompare());
+ if (Ptr != OnlyReadsMemoryTable->end() && strcmp(*Ptr, NamePtr) == 0)
return OnlyReadsMemory;
return UnknownModRefBehavior;
projects / oota-llvm.git / blobdiff