// packed_low = bitwise_and(packed_low, 0x0F)
//
// packed_high = slice(value, [0, value.shape[1] / 2, 0, 0], slice_shape)
// packed_high = left_shift(packed_high, 4)
//
// packed_value = bitwise_or(packed_low, packed_high)
Value PackOperand(OpBuilder &builder, Location loc, Value value, int pack_dim) {
  ShapedType value_type = mlir::cast<ShapedType>(value.getType());
  const int rank = value_type.getRank();