4 ms·

Isn't loongson older than riscv by more than a decade? https://en.m.wikipedia.org/wiki/Loongson https://en.m.wikipedia.org/wiki/Loongson

by zibzab 5y ago

kouteiheika 5y ago
Weren't they using MIPS previously and only recently came up with the new ISA? From the Wikipedia article you've linked to: > Loongson moved to their own processor instruction set architecture (ISA) in 2021 with the release of the Loongson 3 5000 series. So, again, the question is - why just not switch to RISC-V at this point? ...unless this isn't actually very different from MIPS, and is just a renamed clone of MIPS, but they're pretending like it isn't? (Which would answer my question.)
- native_samples 5y ago
  From reading the FAQ it appears to be MIPSish with arbitrary changes and minus the vector extension, with a riscv inspired abi. As for why bother, the goal of the project is Chinese independence from Western tech. Therefore it must be "different" but not different enough to cause much actual work or problems. Think of it as an ISA with Chinese characteristics.
- zibzab 5y ago
  goodson _was_ mips, I assume they made it official mips at some point. so the question is basically the opposite: why riscv when MIPS already existed and was being used by third parties?
  - yjftsjthsd-h 5y ago
    > why riscv when MIPS already existed MIPS, POWER, and SPARC, AIUI - all open enough that you could make your own processor using them.
  - therealcamino 5y ago
    Well, one of the designers of RISC-V was Dave Patterson, who was also the main force behind MIPS 25-ish years earlier. So it's meant to be an improvement, a 5th generation RISC architecture, not just an equal alternative with a different license. I don't know much about the differences, but the system of standardized extensions is pretty cool and makes the same base architecture applicable to a wider range of applications. http://www.riscvbook.com/ http://www.riscvbook.com/

Isn't loongson older than riscv by more than a decade? https://en.m.wikipedia.org/wiki/Loongson https://en.m.wikipedia.org/wiki/Loongson

by zibzab 5y ago

Isn't loongson older than riscv by more than a decade? https://en.m.wikipedia.org/wiki/Loongson https://en.m.wikipedia.org/wiki/Loongson

kouteiheika 5y ago

Weren't they using MIPS previously and only recently came up with the new ISA? From the Wikipedia article you've linked to: > Loongson moved to their own processor instruction set architecture (ISA) in 2021 with the release of the Loongson 3 5000 series. So, again, the question is - why just not switch to RISC-V at this point? ...unless this isn't actually very different from MIPS, and is just a renamed clone of MIPS, but they're pretending like it isn't? (Which would answer my question.)

native_samples 5y ago
From reading the FAQ it appears to be MIPSish with arbitrary changes and minus the vector extension, with a riscv inspired abi. As for why bother, the goal of the project is Chinese independence from Western tech. Therefore it must be "different" but not different enough to cause much actual work or problems. Think of it as an ISA with Chinese characteristics.
zibzab 5y ago
goodson _was_ mips, I assume they made it official mips at some point. so the question is basically the opposite: why riscv when MIPS already existed and was being used by third parties?
- yjftsjthsd-h 5y ago
  > why riscv when MIPS already existed MIPS, POWER, and SPARC, AIUI - all open enough that you could make your own processor using them.
- therealcamino 5y ago
  Well, one of the designers of RISC-V was Dave Patterson, who was also the main force behind MIPS 25-ish years earlier. So it's meant to be an improvement, a 5th generation RISC architecture, not just an equal alternative with a different license. I don't know much about the differences, but the system of standardized extensions is pretty cool and makes the same base architecture applicable to a wider range of applications. http://www.riscvbook.com/ http://www.riscvbook.com/