Method get_grad_var

src/opr/impl/loop/grad.cpp:947–959

}

VarNode* LoopGrad::get_grad_var(size_t inp_idx) {
    auto&& cache = m_grad_result_cache.at(inp_idx);
    if (!cache.first) {
        if (static_cast<GradDesc*>(m_desc.get())
                    ->bind_grad_var(m_fwd_loop_opr->input(inp_idx), output(inp_idx))) {
            cache.second = output(inp_idx);
        } else {
            cache.second = nullptr;
        }
        cache.first = true;
    }
    return cache.second;
}

void LoopGrad::scn_do_execute() {
    mgb_assert(m_nr_scn_do_execute_run + 1 == m_fwd_loop_opr->m_nr_scn_do_execute_run);