Function ggml_opt_alloc

subprojects/llama.cpp/ggml/src/ggml-opt.cpp:724–779

}

void ggml_opt_alloc(ggml_opt_context_t opt_ctx, bool backward) {
    GGML_ASSERT(!opt_ctx->eval_ready);
    if (opt_ctx->build_type == GGML_OPT_BUILD_TYPE_OPT && opt_ctx->opt_period > 1 && opt_ctx->opt_i == 0) {
        ggml_graph_reset(opt_ctx->gb_grad);
    }
    if (backward) {
        const int32_t opt_i_next = (opt_ctx->opt_i + 1) % opt_ctx->opt_period;
        opt_ctx->build_type = opt_i_next == 0 ? GGML_OPT_BUILD_TYPE_OPT : GGML_OPT_BUILD_TYPE_GRAD;
    } else {
        opt_ctx->build_type = GGML_OPT_BUILD_TYPE_FORWARD;
    }

    if (!opt_ctx->static_graphs) {
        ggml_opt_build(opt_ctx);
    }

    struct ggml_cgraph * graph = nullptr;
    switch (opt_ctx->build_type) {
        case GGML_OPT_BUILD_TYPE_FORWARD: {
            graph = opt_ctx->gf;
        } break;
        case GGML_OPT_BUILD_TYPE_GRAD: {
            graph = opt_ctx->gb_grad;
        } break;
        case GGML_OPT_BUILD_TYPE_OPT: {
            graph = opt_ctx->gb_opt;
        } break;
    }
    GGML_ASSERT(graph);

    if (opt_ctx->allocated_graph == graph) {
        opt_ctx->eval_ready = true;
        return;
    }

    ggml_backend_sched_reset(opt_ctx->backend_sched); // clear allocation of previous graph

    if (opt_ctx->static_graphs) {
        ggml_init_params params = {
            /*.mem_size   =*/ graph->size*ggml_tensor_overhead() + ggml_graph_overhead_custom(graph->size, graph->grads),
            /*.mem_buffer =*/ nullptr,
            /*.no_alloc   =*/ true,
        };
        ggml_free(opt_ctx->ctx_copy);
        opt_ctx->ctx_copy = ggml_init(params);

        opt_ctx->allocated_graph_copy = dup_graph(opt_ctx->ctx_copy, graph);
    } else {
        opt_ctx->allocated_graph_copy = graph;
    }

    ggml_backend_sched_alloc_graph(opt_ctx->backend_sched, opt_ctx->allocated_graph_copy);
    opt_ctx->allocated_graph = graph;

    opt_ctx->eval_ready = true;
}

void ggml_opt_eval(ggml_opt_context_t opt_ctx, ggml_opt_result_t result) {