[m-dev.] from [mercury-users] Re: Question regarding determinism

[Fergus Henderson]

On 14-Sep-1998, Peter Schachte <pets at cs.mu.OZ.AU> wrote:
> On Mon, Sep 14, 1998 at 04:00:19PM +1000, Andrew Bromage wrote:
> 
> > > You also keep a list of
> > > the output variables of nondet/multidet goals scheduled so far,
> > 
> > Which is, in general, impossible to tell while you're doing mode
> > analysis if you haven't done determinism inference.
> 
> Ah, maybe I forgot to mention that I'm suggesting doing determinism
> analysis at the same time you're doing mode analysis.  If you're doing
> inference, I really think you should do it bottom-up one SCC at a
> time, for efficiency, but it's not necessary for correctness.

If mode inference is to work, then mode analysis has to be done top-down
(at least unless you change the mode analysis algorithm drastically).
The reason for this is that the initial insts for a procedure are not
known until you've analysed at least one of the calls to that procedure.

Determinism analysis should as you say be done bottom-up, for efficiency.

This is a good argument for keeping these two phases separate ;-)

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3        |     -- the last words of T. S. Garp.