Loongson started with MIPS CPUs but current CPUs are not MIPS-compatible. LoongArch, while being very similar to MIPS, uses a different encoding. And some other details have changed. Better to say, MIPS-inspired.
What are LoongArch's technical advantages over RISC-V? In other words, why should a company develop their own architecture (which then they need to push support for) rather than use an existing, free one?
Back when LoongArch was announced, RISC-V did not yet have enough (ratified) extensions to achieve feature-parity.
Even if it had, LoongArch is much more similar to MIPS. LoongSon would have had to make more microarchitectural changes before being able to tape out their first non-MIPS CPU.
I don't know about advantages, but lead times in the chip business are long and you're not turning around on a dime without very pressing reasons. Loongson has probably had many things in the pipeline as RISC-V started gaining steam. Their current processors are more advanced designs than the best known RISC-Vs.
MarsIronPI|2 months ago
Findecanor|2 months ago
Even if it had, LoongArch is much more similar to MIPS. LoongSon would have had to make more microarchitectural changes before being able to tape out their first non-MIPS CPU.
inejge|2 months ago