Tenstorrent readies stripped-down Ascalon XG CPU without crypto extensions for export

Tenstorrent has published a GCC compiler patch that reveals a new variant of its Ascalon X processor core. The XG model differs from the base X version by dropping the zvkng set of vector cryptographic instructions.

Tenstorrent engineers are already working to add support for the new core to the open-source GCC compiler. The patch, submitted for review to the project's mailing list, mentions the "global version of Ascalon X," suggesting that XG is aimed at markets outside the United States, including China. Removing crypto instructions and reducing throughput appear to align with export restrictions.

In terms of structure, GCC support for Ascalon XG closely mirrors the existing support for Ascalon X. The only difference is the excluded zvkng. The core otherwise retains a full feature set, including rva23s64, zfbfmin, zfh, zkr, zvbc, zvfbfmin, zvfbfwma, zvfh, zvl256b, smaia, smmpm, smnpm, smrnmi, smstateen, ssaia, ssstrict, and svadu. The compiler targets it using the "tt-ascalon-xg" identifier.

Previously, Ascalon X was positioned as a high-performance out-of-order core compliant with the RISC-V RVA23 specification, significantly outpacing the H and S models. The emergence of XG suggests Tenstorrent is looking to broaden its lineup with a feature-reduced option for international customers.

The patch is now under review, and no timeline has been given for when Ascalon XG support will land in the mainline GCC.