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);
}
}
-
+
+
+ // 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;
+
+ // Don't SROA pointers into vectors.
+ if (isa<VectorType>(*I))
+ return MarkUnsafe(Info);
+
+ // Otherwise, we must have an index into an array type. 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.
+ ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand());
+ if (!IdxVal) return MarkUnsafe(Info);
+ if (IdxVal->getZExtValue() >= cast<ArrayType>(*I)->getNumElements())
+ return MarkUnsafe(Info);
+
+ IsAllZeroIndices &= IdxVal->isZero();
+ }
+
// If there are any non-simple uses of this getelementptr, make sure to reject
// them.
return isSafeElementUse(GEPI, IsAllZeroIndices, AI, Info);
// 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);
}
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!
projects / oota-llvm.git / blobdiff