Is there a std-variant for rv64g? And if not, how easy is it to setup for rv64gc? I have an emulator with a known rv64gc bug, and it's faster to emulate uncompr

Is there a std-variant for rv64g? And if not, how easy is it to setup for rv64gc? I have an emulator with a known rv64gc bug, and it's faster to emulate uncompressed instructions (until I start translating them, I guess). Also, what language is the assembler written in? Is it embeddable?