Re: [Qemu-ppc] Implement instructions: yield, mdoio, mdoom

[alarson]

David Gibson <address@hidden> wrote on 06/24/2016 02:17:52 
AM:

DG> Ah.. hmm, yes you might be right.  I think I was mixing up what
DG> gen_pause() did with gen_wait().  I'm having a bit of trouble
DG> working out what an EXCP_HLT will actually do.  A bunch of places
DG> set it, but hardly anywhere actually checks for it.

Well, its probably little consolation, but I had the same problem.
Most of the exception checks seem to be range oriented without
actually checking the values, so typical search techniques don't work
well.

DG> Well.. implementing mdoio and mdoom the same as yield should be
DG> correct if non-optimal.

That was my thought.  I'd still like an opinion on this:

AL> I could either:
AL>   1. Add explicit code for registers 27, 29, and 30, or
AL>   2. Change the existing code to call gen_pause() whenever rs!=0
AL>     (simple noop).
AL> 
AL> My rationale for #2 is that it is simpler, and seems likely to be
AL> right for future encodings of "or".