LoongArch64 subjective higlights
I get back to work on simdutf recently, and noticed that the library gained support for LoongArch64. This is a custom design and custom ISA by Loongson from China. They provide documentation for scalar ISA, but not for the vector extension. Despite that, GCC, binutils, QEMU and other tools already support the ISA. To our luck, Jiajie Chen did an impressive work of reverse engineering the vector stuff and published results online as The Unofficial LoongArch Intrinsics Guide.
These extensions are similar, especially most instructions present in LSX exist in LSAX. According to the Wikipedia entry, the ISA is mixture of RISC-V and MIPS.
ISA supports both integer and floating point instructions. There's support for 8-bit, 16-bit, 32-bit, 64-bit and also 128-bit integers. Floating point instructions cover single precision, double precision and half precision numbers.
My impression is that the ISA is well designed, but have not vectorized any code for that architecture. Below is the list of features I found interesting while browsing the intrinsics guide.
