Function write_u64

gguf-tools/deepseek4-quantize.c:1407–1409

        int64_t v = load_i64_le(src->data + (size_t)i * 8);
        if (v < INT32_MIN || v > INT32_MAX) die("I64 value out of I32 range");
        dst[i] = (int32_t)v;
    }
    return out;
}

static size_t tensor_nbytes(ds4q_type type, const int64_t *ne, int n_dims) {