Re: Confusion: setup-semantics? PC not updated? Immediate operands?

[Hans-Peter Nilsson <hans-peter.nilsson@axis.com>]

> Date: Tue, 29 Jan 2002 23:06:49 -0500
> From: "Frank Ch. Eigler" <fche@redhat.com>

> On Wed, Jan 30, 2002 at 12:46:46PM +1100, Ben Elliston wrote:
> > [...]
> > arm.cpu was the first port to use setup-semantics and back then, we
> > were doing early SID component development.  [...]
> 
> Odd - I thought that this setup-semantics stuff was just an
> experimental stub, like a bunch of other cgen constructs.
> Normally I would try getting this sort of work done outside
> cgen, within the hand-written portion of instruction execution
> loops.

Seeing it in the manual and not marked as experimental made me
think it was ready for the masses.  (Same goes for "condition".)

> As to the original question of who increments the PC, this
> depends on several parameters: whether sid or sim family,
> whether scache or pbb generated kernel.  AFAIK the
> setup-semantics stuff is never actually *necessary*.

Could you please elaborate?  I agree that the setup-semantics
feature isn't necessary in general, though it helps simplifying
the CGEN description.  But you mention this in context of
(incrementing) PC, so it looks as if you mean something
specific.  Not necessary to obtain a PC value?  I can't get a
correct PC value for non-CTI insns.

brgds, H-P