Function ggml_graph_cpy

external/ggml/src/ggml.c:7320–7365

            }
            GGML_ASSERT(node->src[j]->type == GGML_TYPE_F32 || node->src[j]->type == GGML_TYPE_F16);
            node_needs_grad = true;
            break;
        }
        if (!node_needs_grad) {
            continue;
        }

        // inplace operations are currently not supported
        GGML_ASSERT(!node->view_src || node->op == GGML_OP_CPY || node->op == GGML_OP_VIEW ||
            node->op == GGML_OP_RESHAPE || node->op == GGML_OP_PERMUTE || node->op == GGML_OP_TRANSPOSE);

        const size_t ihash = ggml_hash_find(&cgraph->visited_hash_set, node);
        GGML_ASSERT(ihash != GGML_HASHSET_FULL);
        GGML_ASSERT(ggml_bitset_get(cgraph->visited_hash_set.used, ihash));
        if (grad_accs && grad_accs[i]) {
            cgraph->grad_accs[ihash] = grad_accs[i];
            cgraph->grads[ihash]     = cgraph->grad_accs[ihash];
        } else if (node->flags & GGML_TENSOR_FLAG_LOSS) {
            // loss tensors always need a gradient accumulator
            cgraph->grad_accs[ihash] = ggml_new_tensor(ctx, GGML_TYPE_F32, GGML_MAX_DIMS, node->ne);
            cgraph->grads[ihash]     = cgraph->grad_accs[ihash];
        }
        grads_needed[ihash] = true;
    }

    for (int i = n_nodes_f - 1; i >= 0; --i) {
        // inplace operations to add gradients are not created by ggml_compute_backward except for gradient accumulation
        // use allocator to automatically make inplace operations
        ggml_compute_backward(ctx, cgraph, i, grads_needed);
    }

    free(grads_needed);
}

static void * incr_ptr_aligned(void ** p, size_t size, size_t align) {
    void * ptr = *p;
    ptr = (void *) GGML_PAD((uintptr_t) ptr, align);
    *p = (void *) ((char *) ptr + size);
    return ptr;
}

static size_t ggml_graph_nbytes(size_t size, bool grads) {
    size_t hash_size = ggml_hash_size(size * 2);
    void * p = 0;
    incr_ptr_aligned(&p, sizeof(struct ggml_cgraph), 1);
    incr_ptr_aligned(&p, size * sizeof(struct ggml_tensor *), sizeof(struct ggml_tensor *)); // nodes
    incr_ptr_aligned(&p, size * sizeof(struct ggml_tensor *), sizeof(struct ggml_tensor *)); // leafs
    incr_ptr_aligned(&p, hash_size * sizeof(int32_t), sizeof(int32_t)); // use_counts
    incr_ptr_aligned(&p, hash_size * sizeof(struct ggml_tensor *), sizeof(struct ggml_tensor *)); // hash keys