Recently, the infrastructure of Loongson Instruction Set Architecture (LoongArch®) has passed the evaluation of a well-known third-party intellectual property evaluation institution in China and has been officially released.

The Instruction Set Architecture (ISA) constitutes the foundation of the information industry. Therefore, it is almost impossible to build a self-developed IT ecosystem based on imported commercial ISAs. Thanks to over 20 years of CPU development and ecosystem construction experience, Loongson unveiled LoongArch in 2020. This ISA incorporates about 2000 instructions and consists of a compulsory infrastructure and several optional extensions. It defines several standard extensions in the first version, including Loongson Binary Translation (LBT) extension, Loongson Virtualization (LVZ) extension, Loongson SIMD (LSX) extension, and Loongson Advanced SIMD (ASX) extension. LoongArch ISA does not incorporate MIPS ISA.

LoongArch boasts three distinguishing features – fully self-developed, modern techniques, and cross-ISA compatibility.

Loongson attached great importance to the intellectual property of LoongArch and entrusted a well-known third-party intellectual property evaluation institution in China to evaluate the infrastructure of LoongArch thoroughly and carefully. Almost all mainstream ISAs in the world, including ALPHA, ARM, MIPS, POWER, RISC-V, and X86, and tens of thousands of patents related to them have been carefully analyzed. In January 2021, the evaluation institution made the following conclusions:

(1) The ISA framework, instruction format, instruction coding rules, and addressing modes of LoongArch are designed self-independently.

(2) The chapter organizations, instruction description format, and instruction content in the LoongArch ISA manual are distinctly different from those of all mainstream ISAs mentioned above.

(3) No risks of infringement of LoongArch to the Chinese patents of all mainstream ISAs mentioned above have been found.

Loongson has released the ISA manual of LoongArch infrastructure to some specific customers and partners. Once the evaluation completes, Loongson will release the final version of the LoongArch ISA manual to a greater scope of entities. Loongson also plans to cooperate with industry chain partners to establish an open ISA alliance at an appropriate time. The alliance members will be able to use LoongArch ISA and Loongson’s CPU IPs for free.