[RFC] PowerPC DFA description

Daniel Egger degger@fhm.edu
Wed May 29 15:52:00 GMT 2002


Am Don, 2002-05-30 um 00.28 schrieb David Edelsohn:

> 	That is associating instruction types with function units, not
> automata.  How many automata per function unit is a different question --
> at least the way Red Hat generated the initial description.

Seems I was mislead by the automaton names. What about renaming the
vec_alu automaton to something like vector and differentiating between
the units like you did with the IU's on 750 vs. 7450? I'm still unsure 
about how to model the notion of a subunit though; if we hide all three
subunits on the 7400 in one cpu_unit we'd loose the possibility to
schedule optimally since VALU can execute several instructions in
parallel but just one can be issued per cycle.

I take it that the second argument of define_cpu_unit has to be a
automaton and may not be another unit?
 
-- 
Servus,
       Daniel



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