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Re: [cxx-conversion] Make double_int a class with methods and operators. (issue6443093)


Hi,

On Thu, 9 Aug 2012, Mike Stump wrote:

> On Aug 9, 2012, at 8:19 AM, Michael Matz wrote:
> > Hmm.  And maintaining a cache is faster than 
> > passing/returning/manipulating two registers?
> 
> For the most part, we merely mirror existing code, check out 
> lookup_const_double and immed_double_const.

No, I won't without patches on this list.  You keep repeating bragging 
about wide_int during the last two weeks, without offering anything 
concrete about it whatsoever.  You'll understand that I (or anybody else) 
can't usefully discuss with you any merits or demerits of the 
implementation you chose.  (can I btw. complain about the retainment of 
underscores?  If it's a base data type, then why not wideint?  Make that a 
testament for the "quality" of feedback you'll get with the information 
given)

I mean, preparing the audience for an upcoming _suggested_ change in data 
structure of course is fine.  But argueing as if the change happenend 
already, and what's more concerning, as if the change was even already 
suggested and agreed upon even though that's not the case, is just bad 
style.

I would suggest to stay conservative about whatever you have (except if 
it's momentarily materializing), and _especially don't argue against or 
for or not against or for whatever improvement is suggested on the grounds 
that you have a better, as of yet secret but surely taking-over-the-world 
very-soon-now implementation of datastructure X_.  Nobody has seen it yet, 
so you can't expect to get any feedback on it.  Certainly that's the thing 
you need to get it into the code base.

> If the existing code is wrong, love to have someone fix it.  :-)  Also, 
> bear in mind, on a port with with OImode math for example, on a 32-bit 
> host, it would be 8 registers...

Nice try.  But what problem do _you_ want to solve?  For instance why 
should a port with OImode for example be interesting to the FSF?  I hope 
you recognize this as half-rhethorical question, but still, how exactly 
will wide_int help for the goal (which remains to be shown as useful), how 
is it implemented?, why isn't it worse than crap on sensible (i.e. 64bit) 
hosts, and why should everybody not interested in such target pay the 
price, or why isn't there a price to pay for non-OI-targets?

I'm actually more intersted in comments to the first part, but still, 
comments on OI appreciated.


Ciao,
Michael.


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