Function ggml_backend_graph_copy

external/ggml/src/ggml-backend.cpp:2068–2148

}

struct ggml_backend_graph_copy ggml_backend_graph_copy(ggml_backend_t backend, struct ggml_cgraph * graph) {
    GGML_ASSERT(graph);
    struct ggml_hash_set hash_set = ggml_hash_set_new(graph->visited_hash_set.size);
    struct ggml_tensor ** node_copies = (ggml_tensor **) calloc(hash_set.size, sizeof(node_copies[0])); // NOLINT
    bool * node_init = (bool *) calloc(hash_set.size, sizeof(node_init[0]));

    struct ggml_init_params params = {
        /* .mem_size   = */ ggml_tensor_overhead()*hash_set.size + ggml_graph_overhead_custom(graph->size, false),
        /* .mem_buffer = */ NULL,
        /* .no_alloc   = */ true
    };

    struct ggml_context * ctx_allocated = ggml_init(params);
    struct ggml_context * ctx_unallocated = ggml_init(params);

    if (ctx_allocated == NULL || ctx_unallocated == NULL) {
        GGML_LOG_ERROR("%s: failed to allocate context for graph copy\n", __func__);
        ggml_hash_set_free(&hash_set);
        free(node_copies);
        free(node_init);
        ggml_free(ctx_allocated);
        ggml_free(ctx_unallocated);
        return {
            /* .buffer           = */ NULL,
            /* .ctx_allocated    = */ NULL,
            /* .ctx_unallocated  = */ NULL,
            /* .graph            = */ NULL,
        };
    }

    // dup nodes
    for (int i = 0; i < graph->n_nodes; i++) {
        struct ggml_tensor * node = graph->nodes[i];
        graph_copy_dup_tensor(hash_set, node_copies, ctx_allocated, ctx_unallocated, node);
    }

    // allocate nodes
    ggml_backend_buffer_t buffer = ggml_backend_alloc_ctx_tensors(ctx_allocated, backend);
    if (buffer == NULL) {
        GGML_LOG_ERROR("%s: failed to allocate buffer for graph copy\n", __func__);
        ggml_hash_set_free(&hash_set);
        free(node_copies);
        free(node_init);
        ggml_free(ctx_allocated);
        ggml_free(ctx_unallocated);
        return {
            /* .buffer           = */ NULL,
            /* .ctx_allocated    = */ NULL,
            /* .ctx_unallocated  = */ NULL,
            /* .graph            = */ NULL,
        };
    }

    //printf("copy buffer size: %zu MB\n", ggml_backend_buffer_get_size(buffer) / 1024 / 1024);

    // copy data and init views
    for (int i = 0; i < graph->n_nodes; i++) {
        struct ggml_tensor * node = graph->nodes[i];