[LLVMdev] ConstantRange in PR1255

[Stepan Dyatkovskiy]

Hi Duncan,

Yes. ConstantRange has a little bit different purposes instead.
OK. I'll build another Range class then.

-Stepan.
Duncan Sands wrote:
> Hi Stepan,
>
>> Hmmm... why?
>
> because you basically want pairs (set, destination) where set could be a
> arbitrary set of integers. As in practice these sets are a union of a
> small number of intervals, the set abstraction should efficiently represent
> unions of intervals, but that's more of an optimization than anything else.
> Probably for the needs of switch lowering you will need to expose the
> underlying intervals, but the basic abstraction is a set. You could
> build it
> on top of ConstantRange if you like, but as most of ConstantRange is not
> very
> relevant, you could also quite reasonably build it some other way. In
> fact I
> was assuming that that's what you had in mind...
>
> Ciao, Duncan.
>
>> Duncan Sands wrote:
>>> Hi Stepan,
>>>
>>>> Well... each case is represented as pair<BB, vector<Range> >. Right?
>>>
>>> after thinking about this some more I think you are right to not use
>>> ConstantRange, and instead to build your own set abstraction.
>>>
>>> Ciao, Duncan.
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>>
>