# `nvptx-builtins` > NVPTX builtins like `__syncthreads` and `blockIdx.x` ## License The documentation is licensed under - Creative Commons Attribution 4.0 License ([LICENSE-CC-BY](LICENSE-CC-BY) or https://creativecommons.org/licenses/by/4.0/legalcode) And the source code is licensed under either of - Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) - MIT License ([LICENSE-MIT](LICENSE-MIT) or https://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions.