// Select constant vector splats whose value is a power of 2.
//
// In addition to the requirements of selectVSplat(), this function returns
// true and sets Imm if:
// * The splat value is the same width as the elements of the vector
// * The splat value is a power of two.
//
// This function looks through ISD::BITCAST nodes.
// TODO: This might not be appropriate for big-endian MSA since BITCAST is
// sometimes a shuffle in big-endian mode.
bool MipsSEDAGToDAGISel::selectVSplatUimmPow2(SDValue N, SDValue &Imm) const {
APInt ImmValue;
EVT EltTy = N->getValueType(0).getVectorElementType();
if (N->getOpcode() == ISD::BITCAST)
N = N->getOperand(0);
if (selectVSplat (N.getNode(), ImmValue) &&
ImmValue.getBitWidth() == EltTy.getSizeInBits()) {
int32_t Log2 = ImmValue.exactLogBase2();
if (Log2 != -1) {
Imm = CurDAG->getTargetConstant(Log2, EltTy);
return true;
}
}
return false;
}
