Implement expand of BUILD_VECTOR containing variable elements.
This implements CodeGen/Generic/vector.ll:test_variable_buildvector
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26852 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 52c43af..a0c10a0 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -779,8 +779,38 @@
// Otherwise, this isn't a constant entry. Allocate a sufficiently
// aligned object on the stack, store each element into it, then load
// the result as a vector.
- assert(0 && "Cannot lower variable BUILD_VECTOR yet!");
- abort();
+ MVT::ValueType VT = Node->getValueType(0);
+ // Create the stack frame object.
+ MachineFrameInfo *FrameInfo = DAG.getMachineFunction().getFrameInfo();
+ unsigned ByteSize = MVT::getSizeInBits(VT)/8;
+ int FrameIdx = FrameInfo->CreateStackObject(ByteSize, ByteSize);
+ SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, TLI.getPointerTy());
+
+ // Emit a store of each element to the stack slot.
+ std::vector<SDOperand> Stores;
+ bool isLittleEndian = TLI.isLittleEndian();
+ unsigned TypeByteSize =
+ MVT::getSizeInBits(Node->getOperand(0).getValueType())/8;
+ unsigned VectorSize = MVT::getSizeInBits(VT)/8;
+ // Store (in the right endianness) the elements to memory.
+ for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
+ unsigned Offset;
+ if (isLittleEndian)
+ Offset = TypeByteSize*i;
+ else
+ Offset = TypeByteSize*(e-i-1);
+
+ SDOperand Idx = DAG.getConstant(Offset, FIPtr.getValueType());
+ Idx = DAG.getNode(ISD::ADD, FIPtr.getValueType(), FIPtr, Idx);
+
+ Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, DAG.getEntryNode(),
+ Node->getOperand(i), Idx,
+ DAG.getSrcValue(NULL)));
+ }
+ SDOperand StoreChain = DAG.getNode(ISD::TokenFactor, MVT::Other, Stores);
+
+ // Result is a load from the stack slot.
+ Result = DAG.getLoad(VT, StoreChain, FIPtr, DAG.getSrcValue(0));
break;
}
}