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Re: Motion P1788/M0029.01: Level-3-interface-only --- Final version to vote on



> Subject: Re: Motion P1788/M0029.01: Level-3-interface-only --- Final version to vote on
> From: John Pryce <j.d.pryce@xxxxxxxxxxxx>
> Date: Thu, 5 Jan 2012 08:21:19 +0000
> To: stds-1788 <stds-1788@xxxxxxxxxxxxxxxxx>
> 
> Dan
> 
> On 4 Jan 2012, at 20:47, Dan Zuras Intervals wrote:
> >> This might conceivably make sense if you had a 200-processor machine =
> >> where (inf,sup) was more efficient on 100 of the processors, and =
> >> (-inf,sup) was more efficient the other 100, and the compiler inserts =
> >> code to flip the relevant sign bit whenever it sees a datum is flying =
> >> from one kind of processor to the other...??
> > 
> > 	On a heterogeneous collection of machines, interchange
> > 	would happen in exactly this manner.  So the issue of
> > 	operations among [lo,hi] or [-lo,hi], or even [lo,-hi]
> > 	implementations never comes up because one never sees
> > 	more than one implementation on any conforming system.
> 
> I was thinking of a system designed such that the existence of those
> 200 processors is invisible at user level, i.e. there is just one
> conforming system, not 200.
> 
> John

	As you wish.  In order to MAKE the heterogeneity invisible
	to that user there must be a back end that KNOWS which
	style of processor is being compiled to &, therefore, which
	style of interval goes there.  As well as the appropriate
	wrappers for interval interchange.  Don't you agree?  - Dan