Method process_chain

src/gopt/impl/basic_arith/chain.cpp:679–708

}

void ReorderArithChainPass::Impl::process_chain(VarNode* endpoint, Mode mode) {
    if (m_cvprop.is_const(endpoint))
        return;

    auto vars = extract_chain_terms(endpoint, mode);
    if (vars.size() == 1)
        return;

    // to ensure the same set of input terms get the same reduced var
    // TODO: consider maintain a cache(map) of (sorted input terms -> reduced var)
    std::sort(vars.begin(), vars.end(), [](VarNode* x, VarNode* y) {
        return x->id() < y->id();
    });
    m_shp2terms.clear();
    for (auto i : vars) {
        auto inew = m_rewriter.get_var(i);
        m_shp2terms[i->shape()][m_cvprop.is_const(i)].push_back(inew);
    }

    auto sum = reduce_shp2terms(mode);

    if (m_rewriter.get_var(endpoint) != sum) {
        m_rewriter.replace_var(
                endpoint, sum,
                mgb_ssprintf_log(
                        "reorder %zu %s terms", vars.size(),
                        megdnn::Elemwise::ModeTrait::from_mode(mode).name)
                        .c_str());
    }
}

const char* ReorderArithChainPass::name() const {
    return mgb_cstr_log("reorder_arith_chain");