Function ggml_backend_tensor_copy

ggml/src/ggml-backend.cpp:477–498

// backend copy

void ggml_backend_tensor_copy(const struct ggml_tensor * src, struct ggml_tensor * dst) {
    GGML_ASSERT(ggml_are_same_layout(src, dst) && "cannot copy tensors with different layouts");

    if (src == dst) {
        return;
    }

    if (ggml_backend_buffer_is_host(src->buffer)) {
        ggml_backend_tensor_set(dst, src->data, 0, ggml_nbytes(src));
    } else if (ggml_backend_buffer_is_host(dst->buffer)) {
        ggml_backend_tensor_get(src, dst->data, 0, ggml_nbytes(src));
    } else if (!ggml_backend_buffer_copy_tensor(src, dst)) {
#ifndef NDEBUG
        GGML_LOG_DEBUG("%s: warning: slow copy from %s to %s\n", __func__, ggml_backend_buffer_name(src->buffer), ggml_backend_buffer_name(dst->buffer));
#endif // NDEBUG
        size_t nbytes = ggml_nbytes(src);
        void * data = malloc(nbytes);
        ggml_backend_tensor_get(src, data, 0, nbytes);
        ggml_backend_tensor_set(dst, data, 0, nbytes);
        free(data);
    }
}

void ggml_backend_tensor_copy_async(ggml_backend_t backend_src, ggml_backend_t backend_dst, const struct ggml_tensor * src, struct ggml_tensor * dst) {
    GGML_ASSERT(ggml_are_same_layout(src, dst) && "cannot copy tensors with different layouts");