nanoMIPS instruction set support

[XVilka]

nanoMIPS™ Architecture

Designed for embedded devices, nanoMIPS is a variable lengths instruction set architecture (ISA) offering high performance in substantially reduced code size. Under comparable compiler flags, it can deliver up to 40% smaller code than MIPS32. With smaller memory accesses and efficient use of the instruction cache, nanoMIPS also helps to reduce system power consumption.

The nanoMIPS ISA combines recoded and new 16-, 32-, and 48-bit instructions to achieve an ideal balance of performance and code density. It incorporates all MIPS32 instructions and architecture modules including MIPS DSP and MIPS MT, as well as new instructions for advanced code size reduction.

nanoMIPS is supported in release 6 of the MIPS architecture. It is first implemented in the new MIPS I7200 multi-threaded multi-core processor series. Compiler support is included in the MIPS GNU-based development tools.

It is different from the "standard" instruction set.

MIPS_nanomips32_ISA_TRM_01_01_MD01247.pdf

[trufae]

its implemented in c++ in qemu https://github.com/qemu/qemu/blob/master/disas/nanomips.cpp