namespace {
struct VISIBILITY_HIDDEN SROA : public FunctionPass {
static char ID; // Pass identification, replacement for typeid
- explicit SROA(signed T = -1) : FunctionPass((intptr_t)&ID) {
+ explicit SROA(signed T = -1) : FunctionPass(&ID) {
if (T == -1)
SRThreshold = 128;
else
return Changed;
}
+/// getNumSAElements - Return the number of elements in the specific struct or
+/// array.
+static uint64_t getNumSAElements(const Type *T) {
+ if (const StructType *ST = dyn_cast<StructType>(T))
+ return ST->getNumElements();
+ return cast<ArrayType>(T)->getNumElements();
+}
+
// performScalarRepl - This algorithm is a simple worklist driven algorithm,
// which runs on all of the malloc/alloca instructions in the function, removing
// them if they are only used by getelementptr instructions.
(isa<StructType>(AI->getAllocatedType()) ||
isa<ArrayType>(AI->getAllocatedType())) &&
AI->getAllocatedType()->isSized() &&
- TD.getABITypeSize(AI->getAllocatedType()) < SRThreshold) {
+ // Do not promote any struct whose size is larger than "128" bytes.
+ TD.getABITypeSize(AI->getAllocatedType()) < SRThreshold &&
+ // Do not promote any struct into more than "32" separate vars.
+ getNumSAElements(AI->getAllocatedType()) < SRThreshold/4) {
// Check that all of the users of the allocation are capable of being
// transformed.
switch (isSafeAllocaToScalarRepl(AI)) {
continue;
}
+ // Replace:
+ // %res = load { i32, i32 }* %alloc
+ // with:
+ // %load.0 = load i32* %alloc.0
+ // %insert.0 insertvalue { i32, i32 } zeroinitializer, i32 %load.0, 0
+ // %load.1 = load i32* %alloc.1
+ // %insert = insertvalue { i32, i32 } %insert.0, i32 %load.1, 1
+ // (Also works for arrays instead of structs)
+ if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
+ Value *Insert = UndefValue::get(LI->getType());
+ for (unsigned i = 0, e = ElementAllocas.size(); i != e; ++i) {
+ Value *Load = new LoadInst(ElementAllocas[i], "load", LI);
+ Insert = InsertValueInst::Create(Insert, Load, i, "insert", LI);
+ }
+ LI->replaceAllUsesWith(Insert);
+ LI->eraseFromParent();
+ continue;
+ }
+
+ // Replace:
+ // store { i32, i32 } %val, { i32, i32 }* %alloc
+ // with:
+ // %val.0 = extractvalue { i32, i32 } %val, 0
+ // store i32 %val.0, i32* %alloc.0
+ // %val.1 = extractvalue { i32, i32 } %val, 1
+ // store i32 %val.1, i32* %alloc.1
+ // (Also works for arrays instead of structs)
+ if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
+ Value *Val = SI->getOperand(0);
+ for (unsigned i = 0, e = ElementAllocas.size(); i != e; ++i) {
+ Value *Extract = ExtractValueInst::Create(Val, i, Val->getName(), SI);
+ new StoreInst(Extract, ElementAllocas[i], SI);
+ }
+ SI->eraseFromParent();
+ continue;
+ }
+
GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User);
// We now know that the GEP is of the form: GEP <ptr>, 0, <cst>
unsigned Idx =
if (BitCastInst *C = dyn_cast<BitCastInst>(User))
return isSafeUseOfBitCastedAllocation(C, AI, Info);
+ if (isa<LoadInst>(User))
+ return; // Loads (returning a first class aggregrate) are always rewritable
+
+ if (isa<StoreInst>(User) && User->getOperand(0) != AI)
+ return; // Store is ok if storing INTO the pointer, not storing the pointer
+
GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User);
if (GEPI == 0)
return MarkUnsafe(Info);
bool IsAllZeroIndices = true;
- // If this is a use of an array allocation, do a bit more checking for sanity.
+ // If the first index is a non-constant index into an array, see if we can
+ // handle it as a special case.
if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) {
- uint64_t NumElements = AT->getNumElements();
-
- if (ConstantInt *Idx = dyn_cast<ConstantInt>(I.getOperand())) {
- IsAllZeroIndices &= Idx->isZero();
-
- // Check to make sure that index falls within the array. If not,
- // something funny is going on, so we won't do the optimization.
- //
- if (Idx->getZExtValue() >= NumElements)
- return MarkUnsafe(Info);
-
- // We cannot scalar repl this level of the array unless any array
- // sub-indices are in-range constants. In particular, consider:
- // A[0][i]. We cannot know that the user isn't doing invalid things like
- // allowing i to index an out-of-range subscript that accesses A[1].
- //
- // Scalar replacing *just* the outer index of the array is probably not
- // going to be a win anyway, so just give up.
- for (++I; I != E && (isa<ArrayType>(*I) || isa<VectorType>(*I)); ++I) {
- uint64_t NumElements;
- if (const ArrayType *SubArrayTy = dyn_cast<ArrayType>(*I))
- NumElements = SubArrayTy->getNumElements();
- else
- NumElements = cast<VectorType>(*I)->getNumElements();
-
- ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand());
- if (!IdxVal) return MarkUnsafe(Info);
- if (IdxVal->getZExtValue() >= NumElements)
- return MarkUnsafe(Info);
- IsAllZeroIndices &= IdxVal->isZero();
- }
-
- } else {
+ if (!isa<ConstantInt>(I.getOperand())) {
IsAllZeroIndices = 0;
+ uint64_t NumElements = AT->getNumElements();
// If this is an array index and the index is not constant, we cannot
// promote... that is unless the array has exactly one or two elements in
return MarkUnsafe(Info);
}
}
+
+ bool hasVector = false;
+
+ // Walk through the GEP type indices, checking the types that this indexes
+ // into.
+ for (; I != E; ++I) {
+ // Ignore struct elements, no extra checking needed for these.
+ if (isa<StructType>(*I))
+ continue;
+
+ ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand());
+ if (!IdxVal) return MarkUnsafe(Info);
+ // Are all indices still zero?
+ IsAllZeroIndices &= IdxVal->isZero();
+
+ if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) {
+ // This GEP indexes an array. Verify that this is an in-range constant
+ // integer. Specifically, consider A[0][i]. We cannot know that the user
+ // isn't doing invalid things like allowing i to index an out-of-range
+ // subscript that accesses A[1]. Because of this, we have to reject SROA
+ // of any accesses into structs where any of the components are variables.
+ if (IdxVal->getZExtValue() >= AT->getNumElements())
+ return MarkUnsafe(Info);
+ }
+
+ // Note if we've seen a vector type yet
+ hasVector |= isa<VectorType>(*I);
+
+ // Don't SROA pointers into vectors, unless all indices are zero. When all
+ // indices are zero, we only consider this GEP as a bitcast, but will still
+ // not consider breaking up the vector.
+ if (hasVector && !IsAllZeroIndices)
+ return MarkUnsafe(Info);
+ }
+
// If there are any non-simple uses of this getelementptr, make sure to reject
// them.
return isSafeElementUse(GEPI, IsAllZeroIndices, AI, Info);
// It is likely that OtherPtr is a bitcast, if so, remove it.
if (BitCastInst *BC = dyn_cast<BitCastInst>(OtherPtr))
OtherPtr = BC->getOperand(0);
+ // All zero GEPs are effectively casts
+ if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(OtherPtr))
+ if (GEP->hasAllZeroIndices())
+ OtherPtr = GEP->getOperand(0);
+
if (ConstantExpr *BCE = dyn_cast<ConstantExpr>(OtherPtr))
if (BCE->getOpcode() == Instruction::BitCast)
OtherPtr = BCE->getOperand(0);
// If this is a memcpy/memmove, emit a GEP of the other element address.
Value *OtherElt = 0;
if (OtherPtr) {
- Value *Idx[2];
- Idx[0] = Zero;
- Idx[1] = ConstantInt::get(Type::Int32Ty, i);
+ Value *Idx[2] = { Zero, ConstantInt::get(Type::Int32Ty, i) };
OtherElt = GetElementPtrInst::Create(OtherPtr, Idx, Idx + 2,
- OtherPtr->getNameStr()+"."+utostr(i),
+ OtherPtr->getNameStr()+"."+utostr(i),
MI);
}
const Type *EltTy =cast<PointerType>(EltPtr->getType())->getElementType();
// If we got down to a scalar, insert a load or store as appropriate.
- if (EltTy->isFirstClassType()) {
+ if (EltTy->isSingleValueType()) {
if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) {
Value *Elt = new LoadInst(SROADest ? OtherElt : EltPtr, "tmp",
MI);
/// HasPadding - Return true if the specified type has any structure or
/// alignment padding, false otherwise.
-static bool HasPadding(const Type *Ty, const TargetData &TD,
- bool inPacked = false) {
+static bool HasPadding(const Type *Ty, const TargetData &TD) {
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
const StructLayout *SL = TD.getStructLayout(STy);
unsigned PrevFieldBitOffset = 0;
unsigned FieldBitOffset = SL->getElementOffsetInBits(i);
// Padding in sub-elements?
- if (HasPadding(STy->getElementType(i), TD, STy->isPacked()))
+ if (HasPadding(STy->getElementType(i), TD))
return true;
// Check to see if there is any padding between this element and the
}
} else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
- return HasPadding(ATy->getElementType(), TD, false);
+ return HasPadding(ATy->getElementType(), TD);
} else if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) {
- return HasPadding(VTy->getElementType(), TD, false);
+ return HasPadding(VTy->getElementType(), TD);
}
- return inPacked ?
- false : TD.getTypeSizeInBits(Ty) != TD.getABITypeSizeInBits(Ty);
+ return TD.getTypeSizeInBits(Ty) != TD.getABITypeSizeInBits(Ty);
}
/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of
Instruction *User = cast<Instruction>(*UI);
if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
+ // FIXME: Loads of a first class aggregrate value could be converted to a
+ // series of loads and insertvalues
+ if (!LI->getType()->isSingleValueType())
+ return 0;
+
if (MergeInType(LI->getType(), UsedType, TD))
return 0;
} else if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
// Storing the pointer, not into the value?
if (SI->getOperand(0) == V) return 0;
+
+ // FIXME: Stores of a first class aggregrate value could be converted to a
+ // series of extractvalues and stores
+ if (!SI->getOperand(0)->getType()->isSingleValueType())
+ return 0;
// NOTE: We could handle storing of FP imms into integers here!
// We do this to support (f.e.) loads off the end of a structure where
// only some bits are used.
if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth())
- NV = BinaryOperator::createLShr(NV,
+ NV = BinaryOperator::CreateLShr(NV,
ConstantInt::get(NV->getType(),ShAmt),
LI->getName(), LI);
else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth())
- NV = BinaryOperator::createShl(NV,
+ NV = BinaryOperator::CreateShl(NV,
ConstantInt::get(NV->getType(),-ShAmt),
LI->getName(), LI);
// only some bits in the structure are set.
APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth));
if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) {
- SV = BinaryOperator::createShl(SV,
+ SV = BinaryOperator::CreateShl(SV,
ConstantInt::get(SV->getType(), ShAmt),
SV->getName(), SI);
Mask <<= ShAmt;
} else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) {
- SV = BinaryOperator::createLShr(SV,
+ SV = BinaryOperator::CreateLShr(SV,
ConstantInt::get(SV->getType(),-ShAmt),
SV->getName(), SI);
Mask = Mask.lshr(ShAmt);
// in the new bits.
if (SrcWidth != DestWidth) {
assert(DestWidth > SrcWidth);
- Old = BinaryOperator::createAnd(Old, ConstantInt::get(~Mask),
+ Old = BinaryOperator::CreateAnd(Old, ConstantInt::get(~Mask),
Old->getName()+".mask", SI);
- SV = BinaryOperator::createOr(Old, SV, SV->getName()+".ins", SI);
+ SV = BinaryOperator::CreateOr(Old, SV, SV->getName()+".ins", SI);
}
}
return SV;
projects / oota-llvm.git / blobdiff