[PATCH] MIPS: Correct opcode for some IL3A instructions

[Maciej W. Rozycki]

Hi Jiaxun,

> >  Are you sure it is the right reference though?  I looked through
> the 
> > manual and I cannot find encodings for these instructions shown
> anywhere.  
> > Granted, I might well be missing something, given my regrettable lack
> of 
> > skills in Chinese, so I will appreciate a specific page pointer if
> indeed 
> 
> Well, in this document, they didn't exactly mention the opcode, and I
> infered the opcodes by the sequences of these instructions appeared in
> this document.... According my test, they are right.
> 
> After checked all loongson's publictions, I realized no document from
> Loongson can clearly proof this.
> 
> Will acks from Loongson and Lemote staffs be enough to back this
> change?

 For long-term maintenance reasons we require published backing 
documentation for things like instruction encodings, so that for example 
if we spot a bug in code somewhere or do a code rewrite, then we can 
make a fix or go ahead with changes respectively without having to guess 
or chase people who may not be available anymore.

 You don't need to document the semantics of individual instructions.  
Just listing the instruction formats used (i.e. where the individual 
operands go in the instruction word) and opcode encodings will be 
enough.  That is you do not need to disclose anything beyond what is 
already there in libopcodes.

 I don't know why the original submission for the affected instructions 
has been accepted in the first place; we've had this rule for backing 
documentation since forever.

 I hope this clears the situation.  If you have further questions, then 
please let me know.

  Maciej