Method perform_dtr

src/core/impl/graph/seq_dtr.cpp:85–399

}

SeqModifierForDTR::SeqModifyAction SeqModifierForDTR::ModifyActionPlanner::perform_dtr(
        CompNode comp_node, const OprNodeArray& opr_seq, Config* config) {
    prepare(opr_seq);
    SeqModifyAction action;

    if (comp_node.locator().stream < 0) {
        // do not modify system stream oprs
        return action;
    }

    ThinHashSet<Var*> alive_vars;
    size_t cur_usage = 0;
    size_t cur_op_cnt = 0;

    //! map from original var to latest var
    ThinHashMap<VarNode*, Var*> latest_var;
    ThinHashMap<VarNode*, size_t> pin;

    auto need_regen = [&](Var* var) {
        return alive_vars.find(var) == alive_vars.end();
    };

    auto add_alive = [&](Var* var) {
        auto&& ins = alive_vars.insert(var);
        mgb_assert(ins.second);
        cur_usage += var->size;
    };

    auto remove_alive = [&](Var* var) {
        if (alive_vars.erase(var)) {
            auto size = var->size;
            mgb_assert(size <= cur_usage);
            cur_usage -= size;
            return true;
        }
        return false;
    };

    auto get_latest = [&](Var* var) {
        auto iter = latest_var.find(var->orig_var);
        if (iter == latest_var.end()) {
            return var;
        } else {
            return iter->second;
        }
    };

    ThinHashMap<Var*, double> dfs_back;
    ThinHashMap<Var*, double> dfs_ops;
    ThinHashMap<Var*, double> dfs_front;
    ThinHashMap<Var*, double> dfs_mem;
    auto regen_time = [&](Var* var) {
        thin_function<double(Var*)> dfs_b;
        thin_function<double(Var*)> dfs_f;
        dfs_b = [&](Var* var) {
            if (dfs_back.find(var) != dfs_back.end()) {
                return dfs_back[var];
            }