diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 21e7e98c85..6ae44eb353 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -4230,9 +4230,26 @@ SDValue ARMTargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG, // If we are VDUPing a value that comes directly from a vector, that will // cause an unnecessary move to and from a GPR, where instead we could // just use VDUPLANE. - if (Value->getOpcode() == ISD::EXTRACT_VECTOR_ELT) - N = DAG.getNode(ARMISD::VDUPLANE, dl, VT, + if (Value->getOpcode() == ISD::EXTRACT_VECTOR_ELT) { + // We need to create a new undef vector to use for the VDUPLANE if the + // size of the vector from which we get the value is different than the + // size of the vector that we need to create. We will insert the element + // such that the register coalescer will remove unnecessary copies. + if (VT != Value->getOperand(0).getValueType()) { + ConstantSDNode *constIndex; + constIndex = dyn_cast<ConstantSDNode>(Value->getOperand(1)); + assert(constIndex && "The index is not a constant!"); + unsigned index = constIndex->getAPIntValue().getLimitedValue() % + VT.getVectorNumElements(); + N = DAG.getNode(ARMISD::VDUPLANE, dl, VT, + DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, DAG.getUNDEF(VT), + Value, DAG.getConstant(index, MVT::i32)), + DAG.getConstant(index, MVT::i32)); + } else { + N = DAG.getNode(ARMISD::VDUPLANE, dl, VT, Value->getOperand(0), Value->getOperand(1)); + } + } else N = DAG.getNode(ARMISD::VDUP, dl, VT, Value); |