Function exp2

dnn/include/megdnn/dtype/bfloat16.hpp:1875–1877

Binary exponential. \param arg function argument \return 2 raised to \a arg template typename enable ::type exp2(T arg) { return functions::exp2(arg); }

//		template<typename T> typename enable<expr,T>::type exp2(T arg) {
// return functions::exp2(arg); }
MEGDNN_HOST MEGDNN_DEVICE inline expr exp2(bfloat16 arg) {
    return functions::exp2(arg);
}
MEGDNN_HOST MEGDNN_DEVICE inline expr exp2(expr arg) {
    return functions::exp2(arg);
}