Hi Aleksandar, > Your series is getting better and better with each version, which is very > good. For a change, I don't have any objection about the title. :)
Good! > Patch 7 will be integrated shortly in the MIPS queue, you don't need to > worry about it. Thanks! > With this series you are not only supporting your prime use case, but you > are introducing a new instruction set to QEMU. Try to step back and get > wider perspective. No matter how limited the support for the new ISA is, > its introduction to QEMU must have following elements: > > (1) Definition of basic preprocessor constants for the new ISA. > (2) All opcodes for the ISA. > (3) Basic decoding engine for new instructions. > > Your patch 1 adresses 1). However, there are no patches for (2) and (3) in > this series. Let me walk though the details on how to implement (2) and (3). Thank you for your detailed description, it was helpful. > (2) All opcodes for the ISA. > > Only if an R5900 instruction has the same name, opcode, and functionality, > corresponding MIPS III/IV opcode can and must be reused for R5900. For all > other cases, R5900-specific opcode must be supplied. I'll limit further > consideration to MMI instructions, but you should consider the whole R5900 > instruction set. I'm preparing v8 with (2) and (3) and other changes, to be posted shortly. > Of course, you need to specify functions decode_ee_mmi0(), > decode_ee_mmi1(), decode_ee_mmi2(), and decode_ee_mmi3() too. Done. > You can change format and naming in the code above, but I insist that each > unimplemeted instuction has its own "TODO" and "generate_exception()". They have TODOs, but it turns out that having individual generate_exception calls is somewhat impractical, because instructions are typically grouped and folded into other functions in various ways. I think this is reasonable evident when looking at how the v8 patch series develops. > FPU opcodes need such treatment too. This will affect your overall > solution, hopefully it will be better after the reorganization. I'm not sure whether the R5900 FPU opcode anomalies are documented. I will have to investigate this. Fredrik